wilmington source water protection plan
DESCRIPTION
The City of Wilmington developed this Source Water Protection Plan (SWP Plan) in order to better protect its water supply for future generations, reduce long term operating costs and carbon footprint, avoid future treatment requirements, improve planning and response to future spills and water quality events, and leverage upstream investments to protect its water supply.Recognizing the efforts and input of the many dedicated stakeholders in the Brandywine Creek Watershed who have been involved with this SWP Plan is very important. The SWP Plan integrates the significant amount of information from their previous studies and plans. Without the involvement of these stakeholders and the benefit of their previous efforts, this plan would have not been possible.TRANSCRIPT
2010
Crockett Consulting
11/28/2010
City of Wilmington Source Water Protection Plan
Acknowledgements
The following organizations and persons provided significant contributions throughout the Source Water Protection planning effort by the City of Wilmington. Without their efforts, the plan would not have been as successful.
Brandywine Conservancy – Robert Lonsdorf, Kevin Anderson
Brandywine Valley Association – Bob Struble, Jane Fava
Chester County Conservation District – Dan Grieg, Bill Callahan, Christian Strohmeier, Chotty Sprenkle
Chester County Water Resources Authority – Jan Bowers
City of Wilmington – Matt Miller, Colleen Arnold, Sean Duffy, Kara Coats, Kash Srinivasan
University of Delaware Water Resources Authority – Gerald Kauffman and Martha Corrozi
DNREC – Doug Rambo and John Barndt
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City of Wilmington Source Water Protection Plan Executive Summ
Foreword
ary
Producing safe clean and affordable drinking water involves using a multiple barrier approach comprised of three main interrelated steps; (1) protecting source water supply areas, (2) treating drinking water to standards, and (3) monitoring and maintaining the integrity of the drinking water distribution system to ensure successful delivery to customers. However, the single most important barrier continues to be source water protection for the following reasons (Trust for Public Lands, 2004):
• The emergence of new contaminants that suppliers may not be prepared to test or treat
• More frequent spikes in contaminant loads due to storms and flooding that make treatment more challenging
• Constantly changing standards and regulations regarding new contaminants, which are present in the water long before they are identified as threats to public health
• Increases treatment and capital costs due to higher pollutant loads and changing water quality standards
• The loss of natural lands to development impacts not only the quality and quantity of drinking water, but also the cost of treating it.
• With the loss of natural barriers protecting the source water supply, man‐made or engineered barriers must be introduced in treatment.
The constantly expanding diversity of contaminants, coupled with greater pollutant loads and fewer natural barriers, makes treatment more difficult over time and expensive and increase the chances that contaminants will reach the tap. Based on these factors, source water protection is the only approach that reduces the long term vulnerability of the water supplier to these concerns and ultimately is the most sustainable. With the promulgation of the Long Term 2 Enhanced Surface Water Treatment Rule by EPA in 2006, water suppliers are for the first time in history regulated based on the quality of their source water and required to upgrade treatment based on the water quality before it is even treated. This sets a regulatory precedent that can now be continued in the future for other contaminants.
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Throughout the United States and the world, protecting watersheds for drinking water supplies has been shown to be a more cost effective and protective approach to water supplies than building or expanding treatment. In the Northeastern United States alone two of its biggest cities, New York and Boston both rely on heavily forested and protected water supplies to provide high quality drinking water to its citizens. Both cities have chosen to sustain land management of its water supplies in order to save costs. New York City has estimated that if water quality degraded and it was required to filter water that the additional treatment would cost nearly $ 7 billion, with over $300 million in annual operating costs (Trust for Public Lands, 2004). These benefits are not just available to large cities. The town of Auburn, Maine saved $30 million in capital costs, and an additional $750,000 in annual operating costs, by spending $570,000 to acquire land in their watershed. By protecting 434 acres of land around Lake Auburn, the water systems are able to maintain water quality standards and avoid building a new filtration plant (Trust for Public Lands, 2004).
Hundreds of communities have worked to preserve their upstream lands regardless of whether they had reservoirs or were along streams and rivers. This is shown in the desire of citizens to fund conservation of watershed lands to protect water supplies. Hundreds of local governments have passed ballot measures in recent years. During 2002 and 2003 local governments across the United States passed ballot measures that included funding for land conservation (Trust for Public Lands, 2004). Seventy‐five percent (in 2002) and 83 percent (in 2003) of local ballot measures placed before the voters passed around the country. (Trust for Public Lands, 2004)
A recent report from the World Bank concluded that source water protection is no longer a luxury but a necessity
A recent report from the World Bank, titled Running Pure, continues to emphasize the critical need for source water protection. The report concluded that protecting forests around the catchment areas is no longer a luxury but a necessity (Dudley and Stolton, 2003, Barnes, 2009). The World Bank study also concluded when forests are removed, the costs of providing clean and safe drinking water to urban areas increase dramatically (Dudley and Stolton, 2003). Studies by the Trust for Public Lands and the American Water Works Research Foundation (Pyke, Becker, Head, and O’Melia, 2003, Trust for Public Lands, 2004) that compared forested land use to water supply water quality impacts indicated that watersheds with above 40% forested land cover were linked to a higher quality water supply. A higher quality water supply resulted in lower water treatment costs for the water utility. This 40% goal is also suggested by American Forests for urban tree canopies to support green infrastructure (mitigate stormwater impacts) and by studies of forest cover in many watersheds by the Stroud Water Research
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Center indicate that watersheds with greater than 40% forest cover tend to support cold water fisheries and higher water quality, assuming other impacts are minimal (American Forests,
9). 2009, Jackson, 200
Introduction The City of Wilmington developed this Source Water Protection Plan (SWP Plan) in order to better protect its water supply for future generations, reduce long term operating costs and carbon footprint, avoid future treatment requirements, improve planning and response to future spills and water quality events, and leverage upstream investments to protect its water supply.
Recognizing the efforts and input of the many dedicated stakeholders in the Brandywine Creek Watershed who have been involved with this SWP Plan is very important. The SWP Plan integrates the significant amount of information from their previous studies and plans. Without the involvement of these stakeholders and the benefit of their previous efforts, this plan would have not been possible.
Key Water Quality Findings • Chloride and conductivity appear to have the most pronounced and continuous
increasing trends from the early 1970s to current periods in the Lower Brandywine. There is no indication that this trend is “leveling off” or diminishing.
• Alkalinity and hardness appear to have increasing trends that mirror that of chloride and conductivity, but appear to be related to groundwater and base flow changes.
• Total phosphorus appears to be decreasing while total orthophosphate concentrations remain relatively unchanged.
• Nitrate concentrations historically increased since the 1970s, but appear to be leveling off in recent years while ammonia concentrations have decreased historically.
• There were no discernible historical trends observed for total organic carbon (TOC), bacteria/pathogens, total iron and manganese, temperature, and pH. Trends may be occurring, but analytical method variability, analytical detection limits, analytical method changes, and frequency/seasonality of monitoring may not have been able to detect them.
• When turbidity (clarity of the water) in the Brandywine Creek exceeds 10 NTU it has the potential for negative impacts on water treatment and water quality.
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Key Point Source Findings • There are over 700 potential regulated facilities in the watershed. Approximately 35%
of the sources are dischargers, 36% are storage tanks, 16% are septic systems, and the remaining sources include various types.
• Under dry weather conditions, spills from the farthest reaches of the watershed will make it to Wilmington’s intakes in less than 6 days and potentially less than 2 days under normal conditions without delays from impoundments. Under dry weather conditions, spills from the Route 30 corridor such as Coatesville, Exton, and Downingtown can potentially reach Wilmington’s intakes in roughly 1 to 3 days. Under dry weather conditions, spills into the main stem can reach the intake in less than a day in most cases. Under bank full flow (flooding related) conditions, all spills from all locations can potentially reach the Wilmington intake in 5 to 15 hours unless there is a
as in one of the large reservoirs in the basin. delay caused by impoundments such
Key Non Point Source Findings • Contaminant loading estimates suggest non
point sources are the most significant sources of pollution in the watershed.
• The greatest non‐point source contaminant loadings typically come from throughout the West Branch of the Brandywine Creek and its tributaries, mainly due to agricultural land use with some focus in the Coatesville area. The West Branch and its tributaries are high for all contaminant categories including nutrients, sediment, pathogens, and TOC. Only the sections of the East Branch including Downingtown, Exton, and West Chester appeared as areas with high potential loadings for TOC, fecal coliforms, and Cryptosporidium.
During the past decadethe Brandywine Creek watershed lost 10% of its forest cover. How much will be left by 2100?
• The lowest non‐point source contaminant loadings came from throughout the watershed usually focused in areas of low human population. However, these areas may coincide with areas of high loadings due to agricultural activity and suggest potential synergy areas for restoration and preservation work to be combined. In fact, three “synergy” areas were identified; these include Doe Run, Buck Run, and the West Branch of the Brandywine Creek in the Pocopson Township area.
• Livestock and dairy cattle in particular are potentially the most significant source of pathogens and certain emerging contaminants in the watershed.
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Key Land Use Findings • During the past decade the watershed lost 10% of its forest cover. The forest cover that
is preserved in the watershed and development reduction of forest cover will reach a balance point between 2040 and 2100 and no additional forest cover will be gained in the watershed. Therefore, protection of existing forest cover is critical in this century for the future of the watershed.
Wilmington’s Water Quality Priorities Based on the potential source investigations and water quality information, the following are Wilmington’s water quality priorities.
Contaminant Source Priority issue Contaminants Addressed
Agriculture Dairy Farms, cows in stream, manure management
Cryptosporidium, pathogens, nutrients, turbidity,
disinfection by products, trace organics (antibiotics)
Wastewater Raw and untreated sewage discharges, outbreaks
Cryptosporidium, pathogens, trace organics, baseflow,
nutrients Urban/Suburban Runoff Road Runoff, Streambank
erosion Turbidity, sodium & chloride,
baseflow
Riparian buffer removal Streambank erosion Disinfection by products, turbidity
Summary of Recommended Implementation Activities Based on the information compiled, a series of goals, objectives, indicators, and implementation tasks (short and long term) were developed for the City of Wilmington’s water supply. Overall, 4 major goals, 29 major objectives, 78 implementation tasks covering various time periods, and 46 potential progress indicators were created as part of the implementation plan for Wilmington to initiate and sustain a Source Water Protection Program that can lead to successful achievement of its goals.
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Implementation of the various objectives is further broken down into definable tasks at various time scales in order to be accomplished. The various tasks can be divided into the following types of major implementation activities:
• Agricultural Mitigation
• Agricultural Preservation
• Forest Preservation
• Riparian Buffer Restoration and Forest Reforestation
• Wastewater Discharge Enhancement and Emergency Response Preparation and Communication
• Stormwater Runoff Mitigation
• Stakeholder Partnerships and Outreach & Public Education
• Monitoring & Technical Studies
• Hoopes Reservoir Protection
• Financial Support and Analysis
These activities can have short term and long term elements as well as localized and watershed wide components. These elements can be implemented with partners and other sources of funding. In most cases, Wilmington’s role will be technical support or helping stakeholder to access other funding sources. In some cases, Wilmington may need to take the lead to implement the activity. The most important source water protection activities for the
are described below. previously mentioned categories
Agricultural Mitigation
Agricultural Mitigation is a low cost / high return mitigation activity. Honey Brook is the top priority area for this work.
Mitigating agricultural impacts provides benefits to the water supply. It prevents and reduces pathogens such as Cryptosporidium, sediment, livestock pharmaceuticals, ammonia, nitrate, and phosphorus. A study by AWWA and the Trust for Public Lands of water supplies suggested that for every 4 percent increase in raw water turbidity, treatment costs increase 1 percent. (Trust for Public Lands, 2004)
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Agricultural mitigation efforts need to focus the primary efforts on the Honey Brook Township area of the West Branch of the Brandywine Creek. There are 1,700 acres of land and 25 miles of stream in need of protection in this priority area. In order to protect the Honey Brook clusters, roughly 10% or 170 acres or 2.5 miles of streambank would need mitigation annually. It will require about $217,000 per mile of streambank with fencing with a total cost of over 5 million dollars to ultimately address the Honey Brook township clusters.
In the New Castle County section of the main stem of the Brandywine Creek, activities need to focus on projects to get cows and livestock out of the tributaries to the main stem Brandywine Creek from the City’s intake upstream to the Delaware border. There are roughly 3 miles of tributaries and stream along agricultural properties in Delaware upstream of Wilmington’s intake that requires some level of mitigation or protection. There are also 92 acres of pasture areas that will need examination for potential mitigation. It should be an immediate priority to implement streambank fencing in areas where livestock are accessing the stream in Delaware and a long term effort to protect the remaining areas in Delaware.
Throughout the watershed the most important mitigation activities include streambank fencing and implementation of conservation and nutrient management plans at dairy and livestock farms. Approximately $450,000 per year of funding in the watershed from various non City sources should be dedicated to these efforts with a total of 8.9 million dollars to implement 20 miles of streambank fencing and mitigation work at 100 farms over the next 10 to 20 years. Some potential partners for this effort include the Pennsylvania Department of Environmental Protection, Chester County Conservation District, New Castle County Conservation District, Delaware Natural Resources Environmental Conservation, Chester County, United States Department of Agriculture, Natural Resources Conservation Service, Trout Unlimited, Duck Unlimited. Wilmington’s role will be mostly related to technical support and assistance in accessing other funding sources with some potential for direct funding assistance if leveraging is available.
Agricultural Preservation Agricultural preservation provides benefits to the water supply because properly managed and preserved farmland can support significant riparian buffers and prevents the addition of urban/suburban stormwater challenges due to development. A study by AWWA and the Trust for Public Lands of water supplies suggested that for every 4 percent increase in raw water turbidity, treatment costs increase 1 percent. (Trust for Public Lands, 2004)
Agricultural Preservation efforts should focus on preserving as much farmland as possible in riparian buffer areas along first and second order streams by 2100. This will cost about $5 million per year and attempt to preserve over 69 square miles of farmland (roughly 60% of
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existing farmland in the watershed). The 2,700 acres of farmland along first order streams in the Honey Brook area on the West Branch represents prime agricultural parcels should be the primary preservation target area of the initial 5 to 10 year period. In New Castle County there is approximately 1,778 acres of farmland that needs to be assessed for its preservation status.
Some potential partners for this effort include the Pennsylvania Department of Environmental Protection, Brandywine Conservancy, Chester County Conservation District, New Castle County Conservation District, Delaware Natural Resources Environmental Conservation, Delaware Nature Society, Chester County, United States Department of Agriculture, Natural Resources Conservation Service, Trout Unlimited, Duck Unlimited. Wilmington’s role will be mostly related to technical support and assistance in accessing other funding sources with some potential for
veraging is available. direct funding assistance if le
Forest Preservation Forests prevent pathogens such as Cryptosporidium, road salts, and increased flows due to development. Forests also have significant buffer impacts that reduce/filter sediment, ammonia, nitrate, and phosphorus. Treatment costs increase as forested lands drop below 40% of the watershed. For every 10 percent increase in forest cover in the source area, treatment and chemical costs decreased approximately 20 percent, up to about 60 percent forest cover as reported in a study by AWWA and the Trust for Public Lands (Trust for Public Lands, 2004). As noted in this plan, the forested land cover of the Brandywine Watershed is estimated at approximately 28% forested land cover in 2009 (data provided by GIS estimates by Brandywine Conservancy). Based on historical development rates and woodland loss information (Brandywine Conservancy report reference 2009), over the past 10 to 15 years there has been an average 1% per year loss in forested lands. This equals approximately 9.09 square miles of forested land lost per decade to development pre‐recession. Forest Preservation is a long
term protection activity The Upper East Branch areas of Perkins and Indian Run is a top priority area
Forest Preservation efforts need to focus the short term efforts on the Perkins Run and Indian Run cluster areas along first order streams. Within the Delaware portion of the Brandywine Watershed there is approximately 1,000 acres of riparian forested lands that need to be examined for preservation.
Preservation of priority areas will require about $800,000 per year and protect 2 miles of stream bank and 1,000 acres per year. Watershed wide, approximately 75 square miles, need to be preserved at a cost of approximately 48 million dollars. Some potential partners for this
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effort include the Pennsylvania Department of Conservation of Natural Resources, Chester County Water Resources Authority, New Castle County, Delaware Natural Resources Environmental Conservation, Chester County, Brandywine Conservancy, Brandywine Valley Association, Natural Lands Trust, Trust for Public Lands, William Penn Foundation, Conservation Fund, Pennsylvania Environment Coalition, Delaware Horticultural Society, Delaware Nature Society. Wilmington’s role will be mostly related to technical support and assistance in accessing other funding sources with some potential for direct funding assistance if leveraging is available.
Riparian Buffer Restoration & Forest Reforestation Riparian Buffer Restoration efforts require a detailed watershed wide analysis and groundtruthing of riparian buffer gaps to be completed. The first step requires facilitating a watershed wide reforestation plan by stakeholders. In the meantime until complete watershed wide information is available, initial efforts by the City of Wilmington should be piloted within the tributaries to the main stem in New Castle County where detailed information is available and effectiveness can be monitored. Detailed information provided by the Brandywine Conservancy suggests the lands in the Wilson Run tributary and the agricultural lands near Smiths Bridge Road in Ramsey Run, Beaver Run, and an unnamed tributary are the greatest priority. This work involves a relatively limited number of stakeholders and property owners. The City of Wilmington should immediately meet with these stakeholders to discuss ways to improve riparian buffer protection in these areas.
In addition, a watershed wide initiative for reforestation should be developed that is linked to potential funding sources via carbon credits, carbon sequestration, or carbon cap and trade programs for energy suppliers and businesses. Many large industries reside in the watershed and region that may be interested in this approach. However a framework needs to be developed that regulators will accept and a champion to administer and implement the program will need to be identified.
Can watershed reforestation be funded by linking it to carbon credits and greenhouse gas emissions?
Some initial steps to starting this effort include the following:
• Develop programs to reforest key riparian parcels upstream of COW intake in New Castle County along the main stem and first order streams.
• Assist stakeholders to obtain funding to complete a reforestation plan for the watershed.
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• Develop funding agreements with Brandywine Conservancy and Brandywine Valley Watershed association to leverage specific reforestation efforts in first order streams or headwaters areas.
• Develop regional initiative with BC, BVA, water suppliers, and Chester County to reforest remaining forested riparian buffer lands along first and second order streams by 2100.
• Support initiatives by partners to develop a “forest bank” related reforestation approach that is supported by carbon sequestration and greenhouse gas emission trades in the region.
Wastewater Discharge Enhancements and Emergency Response Preparation and Communication These activities should result in improved response and awareness of upstream accidents and activities that could result in acute water quality events or long term water quality changes that will impact Wilmington’s intakes. Point source management should focus on the following priority activities:
• Support upgrades to advanced tertiary and UV treatment to mitigate pathogens
• Enhance communications with Health Departments regarding upstream occurrence of waterborne or gastrointestinal disease events
• Increase communication for improved responses in case of accident
• Receive calls from Marsh Creek Lake during releases
• Develop internal protocols to respond to calls from upstream dischargers, water suppliers, etc.
• Visit high priority point sources to improve awareness for downstream notifications
• Develop appropriate phone and contact information list for high priority point sources immediately.
Emergency response efforts should focus on the following priority activities:
• Visit high ranked facilities upstream, update internal information, and exchange emergency contact information
• Visit all major upstream discharges upstream and exchange contact information
• Contact Chester County Health and get added to phone chain for spills
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• Investigate enrolling in Delaware Valley Early Warning System
• Improve notification about reservoir releases upstream (CWRA)
• Enhance the turbidity early warning system to include conductivity warnings for road salt application
• Contact emergency responders in NCC upstream of COW intake and drinking water to communicate water supply sensitivity to wash down and accidents.
• Design and install water supply educational roadway signs at key locations in the watershed & Hoopes Reservoir.
Wilmington’s role will be mostly related to technical support and direct outreach and alth departments, and emergency responders. communication with upstream facilities, he
Stormwater Runoff Mitigation Stormwater management should focus on the following priority activities:
• Support riparian buffer ordinance protections upstream in DE and PA
• Identify opportunities to match SWP efforts with ACT 167 and Chester County Ordinance Initiatives (Landscapes, Watersheds, etc.)
• Monitor TMDL activities related to upstream MS4 permits
• Assist/facilitate creation of upstream stormwater utilities
• Set up a pilot project with DELDOT and COW for using brining to reduce road salt application near intake
• Examine the potential for ordinances to minimize salt use on private parking lots
Wilmington’s role will be mostly related to technical support and sharing information on administering a stormwater utility.
Stakeholder Partnerships Stakeholder partnership efforts should focus on the following priority activities:
• Implementation of the SWP Ordinance
• Obtain approval and endorsement of the Wilmington Source Water Protection Plan by key stakeholders, PADEP, DNREC, and EPA Region 3
• Integration of the SWP Plan into stakeholder activities through education
• Participate in the Phase 7 scope of work development for the EPA Watersheds Grant
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• Working with stakeholders at Hoopes Reservoir for reforestation of the buffer area.
• Conduct workshops to enroll upstream golf courses in the Audubon Certification Program
• Design and install water supply educational roadway signs at key locations in the Brandywine Creek watershed (near the intakes) & Hoopes reservoir areas.
• Arrange SWP Program in order to submit application for AWWA Accreditation
Wilmington’s role will be mostly related to direct outreach and communication with upstream stakeholders.
Monitoring Awareness, understanding, and knowledge of water quality trends, phenomena, and events through monitoring can allow for predictive and preventative actions to protect the water supply or enhance its treatment. Monitoring efforts should focus on the following priority activities:
• Microbial source tracking study completion and evaluation
• Add conductivity to early warning system upstream where needed
• Continue to track and evaluate watershed pharmaceutical monitoring efforts
• Updating long term monitoring trends
Wilmington’s role will be mostly related to technical and financial support and direct participation of monitoring studies.
Hoopes Reservoir Protection Hoopes Reservoir management should focus on the following priority activities:
• Conduct forest survey of Hoopes
• Improve markers of COW Property boundaries
• Create an enforcement process for deforestation
• Educate adjacent property owners
• Reforest the Hoopes Area in coordination with neighboring landowners
• Identify areas for critical land acquisition/easements around Hoopes if any remain
• Initiate communication and education of emergency responders near Hoopes
Wilmington’s role will be mostly related to direct implementation and leadership of these activities by COW staff.
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Financial Support and Analysis Long term funding will lead to consistent implementation of water supply protection goals. Without funding programs in the watershed will not be able to mitigate current and future pollution sources and the water quality will degrade in the Brandywine Creek. Given the current global economic situation funding for these efforts is limited and highly competitive. Funding efforts should focus on two parallel tracks. The first effort will include efforts to support leveraging and obtaining funds through traditional grant opportunities with stakeholders for specific defined projects and efforts. The second effort will require working with stakeholders such as the University of Delaware Water Resource Agency to identify the value of the Brandywine and develop a sustainable source of funding in the watershed from non‐grant sources.
Recommended Immediate Priority Activities It may be difficult to determine where to start implementing the Source Water Protection Plan with the limited resources available since there are such a large number of activities recommended in the plan. The following activities are recommended for initial implementation.
• Implement the SWP Ordinance • Facilitate and support streambank fencing directly upstream in New Castle County • Continue to leverage preservation efforts with watershed partners • Partner with Brandywine Conservancy on larger efforts for forest preservation and
reforestation • Implement several streambank fencing projects in the Honey Brook area with BC, CCCD,
and BVA and evaluate the benefits to Wilmington • Estimate the cost benefit and long term impacts of deforestation of the watershed on
long term water quality and treatment costs • Enhance current protocols for Hoopes Reservoir usage due to Brandywine Creek water
quality • Develop and establish protocols to respond to upstream notifications • Familiarize staff with watershed and key upstream dischargers and information on
watershed • Continue to build partnerships with upstream stakeholders • Present the SWP Plan to stakeholders and educate City officials • Obtain endorsement of the SWP Plan by City Council • Initiate monitoring for the Microbial Source Tracking Project • Identify and leverage opportunities through the Christina Coalition • Initiate road salt reduction discussions and develop a pilot project
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TABLE OF CONTENTS
1. Section 1 - Overview of Source Water Program and Protection Plan .................... 5
1.1. Introduction ......................................................................................................................................... 5
1.2. Background on Source Water Assessments ....................................................................... 7
1.3. Key Findings of Source Water Assessments ....................................................................... 9
1.4. Relating the Source Water Assessments to the Protection Plan ......................... 14
1.5. Other Data Informing the Protection Plan ....................................................................... 14
1.6. Implementing Projects Outlined in the Protection Plan .......................................... 14
2. Section 2 - Watershed Description, Characterization, & Analysis ....................... 15
2.1. Watershed & Surface Water intakes ................................................................................... 15
2.1.1. General Overview ................................................................................................................ 15
2.1.2. Physiography and Geology ............................................................................................. 23
2.1.3. Soils ............................................................................................................................................. 28
2.1.4. Hydrology ................................................................................................................................ 31
2.1.5. Reservoirs & Impoundments In The Watershed ............................................... 41
2.1.6. First Order Streams ............................................................................................................ 44
2.1.7. Watershed Growth, Population, and Land Use Impacts ................................ 47
2.1.8. The Value of Watershed Preservation and Reforestation ............................ 49
2.2. Surface Water Intakes ................................................................................................................. 55
2.2.1. Surface Water Withdrawals and Community Water Systems ......................... 55
2.2.2. Groundwater Withdrawals ................................................................................................. 62
2.2.3. Time of Travel Delineations .......................................................................................... 67
2.3. Identification of Universal Water Quality Issues ......................................................... 71
2.3.1. Summary of Wilmington Intake Water Quality Data (1996-2007) ......... 73
2.3.2. General Potential Seasonal and Source Impacts ................................................ 76
2.3.3. Inorganics ................................................................................................................................ 79
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2.3.4. Chloride & Conductivity Trends From Road Salts ............................................. 80
2.3.5. Alkalinity Impacts on TOC Removal and Corrosion Control ....................... 85
2.3.6. High Turbidity Impacts on Wilmington Intake Water Quality and Treatment ..................................................................................................................................................... 88
2.3.7. Pathogens ................................................................................................................................ 91
2.3.8. Giardia and Cryptosporidium ........................................................................................ 93
2.3.9. Disinfection by Product Pre-cursors ........................................................................ 96
2.3.10. Nutrients .................................................................................................................................. 98
2.3.11. Algae ........................................................................................................................................ 101
2.3.12. Trace Organics ................................................................................................................... 104
2.3.13. Metals ...................................................................................................................................... 106
2.3.14. Long Term Water Quality and Historical trends 1979-2007 ................... 109
2.3.15. Spatial Comparison of Water Quality Trends ................................................... 114
2.3.16. Comparison of Water Quality by Land use, Location, and Weather ..... 115
2.3.16.1. TSS and Nutrients Spatial Comparison ........................................................... 116
2.3.16.2. Bacteria Spatial Data Comparison ..................................................................... 117
2.4. Potential Sources of Contamination Analysis ............................................................. 120
2.4.1. Point Sources Inventory ............................................................................................... 120
2.4.2. Upstream Discharges & Baseflow impacts ......................................................... 141
2.4.3. Point Source Loadings ................................................................................................... 141
2.4.4. Non Point Sources Inventory ..................................................................................... 145
2.4.5. Non Point Source Loadings ......................................................................................... 151
2.4.6. Comparison of Point & Non Point Source Loadings ...................................... 159
3. Section 3 - Prioritization of Potential Sources and Identification of Restoration & Protection Projects ........................................................................................................................ 161
3.1. Priority Issues in the Watershed........................................................................................ 161
3.2. Prioritization Methodology ................................................................................................... 162
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3.3. Prioritization Results – Point Sources ............................................................................ 164
3.4. Priority Non-Point Source Areas – Subwatershed Rankings .............................. 175
3.4.1. Priority Non-Point Sources –Priority Cluster Areas for Agricultural Mitigation ................................................................................................................................................... 181
3.4.2. Priority Areas For Stormwater Mitigation ......................................................... 189
3.4.3. Priority Non-Point Sources – High Priority Geographical Areas for Preservation ............................................................................................................................................. 194
3.4.4. Priority Non-Point Sources – High Priority Geographical Areas for Riparian Buffer Restoration, Reforestation, and Preservation ................................... 207
3.5. Common Priorities with Stakeholders ............................................................................ 228
3.6. Brandywine Watershed / Christina Basin Clean Water Partnership Stakeholder Efforts & Projects ............................................................................................................ 229
4.1. Funding Sources in the Brandywine Watershed ....................................................... 233
4.2. Public Outreach ........................................................................................................................... 238
4.2.1. Within the City of Wilmington ................................................................................... 238
4.2.2. Upstream Partner Outreach ....................................................................................... 238
4.3. Policy Issues ............................................................................................................................. 239
4.3.1. Needed Policy Changes .................................................................................................. 239
5. Section 5 - Emergency Preparedness, Spill Response, & Contingency Planning 240
5.1. Turbidity Early Warning System ........................................................................................ 240
5.2. Upstream Notification & Communication ..................................................................... 246
5.3. Emergency Response Tools ................................................................................................... 249
5.4. Contingency Planning ............................................................................................................... 249
5.4.1. Contaminant Response Plans for Accidental or Deliberate Release into Source of Potable Waters .................................................................................................................. 249
5.5. Alternative Supplies .................................................................................................................. 250
6. Section 6 – Regulatory Compliance & AWWA Certification .................................. 251
6.1. LT2ESWTR & Stage 2 DBPR ................................................................................................... 251
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6.2. Watershed Control Program Certification Evaluation ........................................... 254
6.3. AWWA SWP Accreditation Evaluation ............................................................................ 257
7. Section 7 - Brandywine Watershed Source Water Protection Objectives, Progress Indicators, & Implementation Activities ................................................................. 260
7.1. SWP Goals ........................................................................................................................................ 260
7.2. SWP Objectives ............................................................................................................................. 261
7.3. Implementation Activities ..................................................................................................... 263
7.3.1. Agricultural Mitigation .................................................................................................. 264
7.3.2. Agricultural Preservation ............................................................................................ 268
7.3.3. Forest Preservation ........................................................................................................ 271
7.3.4. Riparian Buffer & Forest Reforestation ............................................................... 274
7.3.5. Wastewater Discharge Enhancements and Emergency Response Preparation and Communication ................................................................................................. 277
7.3.6. Stormwater Runoff Mitigation .................................................................................. 278
7.3.7. Stakeholder Partnerships and Public Education & Outreach ................. 279
7.3.8. Monitoring & Technical Studies ............................................................................... 280
7.3.9. Hoopes Reservoir Protection .................................................................................... 281
7.3.10. Financial Support and Analysis ................................................................................ 282
7.4. Recommended Immediate Priority Activities ............................................................ 283
7.5. Cost Estimates ............................................................................................................................... 284
7.6. Progress Indicators ................................................................................................................... 284
Works Cited .......................................................................................................................................... 293
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1. Section 1 - Overview of Source Water Program and Protection Plan
1.1. Introduction
Producing safe clean and affordable drinking water involves using a multiple barrier approach comprises three main interrelated steps; (1) protecting source water supply areas, (2) treating drinking water to standards, and (3) monitoring and maintaining the integrity of the drinking water distribution system to ensure successful delivery to customers. However, the single most important barrier continues to be source water protection for the following reasons (Trust for Public Lands, 2004):
• The emergence of new contaminants that suppliers may not be prepared to test or treat
• More frequent spikes in contaminant loads due to storms and flooding that make treatment more challenging
• Constantly changing standards and regulations regarding new contaminants, which are present in the water long before they are identified as threats to public health
• Increased treatment and capital costs due to higher pollutant loads and changing water quality standards
• The loss of natural lands to development impacts not only the quality and quantity of drinking water, but also the cost of treating it.
• With the loss of natural barriers protecting the source water supply, man-made or engineered barriers must be introduced in treatment.
These constantly expanding diversity of contaminants, coupled with greater pollutant loads and fewer natural barriers, over time will make treatment more difficult and expensive and increase the chances that contaminants will reach the tap. Based on these factors, source water protection is the only approach that will reduce the long term vulnerability of the water supplier to these concerns and will ultimately be the most sustainable. With the promulgation of the Long Term 2 Enhanced Surface Water Treatment Rule by EPA in 2006, water suppliers are for the first time in history regulated based on the quality of their source water and required to upgrade treatment based on the water quality before it is even treated. This sets a regulatory precedent that can now be continued in the future for other contaminants.
Throughout the United States and the world protecting watersheds for drinking water supplies has been shown to be a more cost effective and protective approach to water supplies. In the Northeastern United States alone two of its biggest cities, New York and Boston both rely on heavily forested and protected water supplies to provide high quality drinking water to its citizens. Both cities have chosen to sustain land management of its
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water supplies in order to save costs. New York City has estimated that if water quality degraded and it was required to filter the water that the additional treatment would cost nearly $ 7 billion, with over $300 million in annual operating costs (Trust for Public Lands, 2004). These benefits are not just available to large cities. The town of Auburn, Maine saved $30 million in capital costs, and an additional $750,000 in annual operating costs, by spending $570,000 to acquire land in their watershed. By protecting 434 acres of land around Lake Auburn, the water systems are able to maintain water quality standards and avoid building a new filtration plant (Trust for Public Lands, 2004).
Hundreds of communities have worked to preserve their upstream lands regardless of whether they had reservoirs or were along streams and rivers. This has been shown by the desire of citizens to fund conservation of watershed lands to protect water supplies. Hundreds of local governments have passed ballot measures in recent years. During 2002 and 2003 local governments across the United States passed ballot measures that included funding for land conservation (Trust for Public Lands, 2004). Seventy-five percent (in 2002) and 83 percent (in 2003) of local ballot measures placed before the voters passed around the country. (Trust for Public Lands, 2004)
A recent report from the World Bank, titled Running Pure, continues to emphasize the critical need for source water protection. The report concluded that protecting forests around the catchment areas is no longer a luxury but a necessity (Dudley and Stolton, 2003, Barnes, 2009). The World Bank study also concluded when forests are removed, the costs of providing clean and safe drinking water to urban areas increase dramatically (Dudley and Stolton, 2003). Studies by the Trust for Public Lands and the American Water Works Research Foundation (Pyke, Becker, Head, and O’Melia, 2003, Trust for Public Lands, 2004) that compared forested land use to water supply water quality impacts indicated that watersheds with above 40% forested land cover were linked to a higher quality water supply. A higher quality water supply resulted in lower water treatment costs for the water utility. This 40% goal is also suggested by American Forests for urban tree canopies to support green infrastructure (mitigate stormwater impacts) and by studies of forest cover in many watersheds by the Stroud Water Research Center which indicate that watersheds with greater than 40% forest cover tend to support cold water fisheries and higher water quality, assuming other impacts are minimal (American Forests, 2009, Jackson, 2009).
Source Water Protection is the first step of the multiple barrier approach that focuses on mitigating current and future water supply contamination. The basic principle of source water protection is simply that the cleaner the water at the source, the less it must be treated to provide safe drinking water. With rapidly increasing energy and chemical costs for water treatment in recent years, source water protection is more than a precautionary activity, but also a potential long term cost savings program. Also, as water utilities start adopting a triple bottom line approach which includes economic, environmental, and social costs the source water protection approach will become a more integral part of the business model for water utilities.
Source water protection, though already employed by many water utilities, was given a significant amount of national attention due to Federal legislation in 1996. The Safe Drinking Water Act Reauthorization of 1996 required states to develop a Source Water
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Assessment and Protection (SWAP) Program. This program was designed to assess the drinking water sources that serve public water systems for their susceptibility to pollution and to use this information to eventually build voluntary, community-based barriers to drinking water contamination such as source water protection plans. These assessments were of the raw water quality, not of finished water quality or of water supplier compliance with standards.
The source water protection process can be summarized in three basic steps, 1) identify and prioritize the potential contaminants of drinking water, 2) determine the pathways by which these contaminants enter the source water, both surface water and groundwater, and 3) develop methods and programs which reduce or eliminate the contamination of water used for drinking water supply. The Source Water Assessment Program (SWAP) addressed number 1) above, the identification and prioritization of potential contaminants within the watershed of a source water. The Source Water Protection Plan efforts of Wilmington are focused on addressing numbers 2) and 3) above.
1.2. Background on Source Water Assessments
The USEPA established a new requirement under Section 1453 of the 1996 Safe Drinking Water Act. The Act requires each state to develop a Source Water Assessment and Protection Program (SWAP) to evaluate all drinking water sources that serve public drinking supplies and to provide a mechanism for development of local protection programs. As part of the requirement all surface water sources in the United States were investigated for potential sources of contamination and vulnerability to pollution.
In 1996 the U.S. Congress amended the Safe Drinking Water Act (SDWA) establishing a Source
Water Assessment and Protection Program (SWAPP). The program, coordinated nationally by
the U.S. Environmental Protection Agency (EPA), requires all states to develop a plan for
evaluating the drinking water supply sources used by public water systems in their state and then
follow the plan to conduct source water susceptibility assessments. Susceptibility assessments
will include a determination of the area that has the greatest affect on the quality of each public
drinking water source and an inventory of the potential contaminants within the designated area.
The ultimate goal of the SWAPP was to provide local government the information it needs to
improve the protection of public drinking water sources through its land management authority. It
should be recognized that for many years the primary mechanism for insuring the safety and
quality of drinking water has been water treatment facilities. Public water suppliers have spent
billions of dollars developing sophisticated water treatment techniques that remove materials that
are harmful to our health. The SWAPP was designed to another protective mechanism to
safeguard drinking water supplies by identifying the potential sources of contamination that may
affect raw water quality and providing assistance in managing or eliminating these potential
contaminant sources.
In October 1999 the U.S. EPA formally approved Delaware’s Source Water Assessment Plan
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which outlined the methodology Delaware followed to determine the susceptibility of the 582 public water systems in the state. All assessments followed the same general approach, although the details may vary depending on the size of the water system. The Delaware Source Water Assessment conducted by the University of Delaware Water Resources Association used the following four step approach.
1. Delineate the source water areas for each intake (watershed) or well (wellhead).
Initially, the area most important to water quality for each public system was mapped. For surface water, the watershed area upstream of the intake was examined, with particular attention focused on areas adjacent to streams and tributaries.
2. Determine the vulnerability of each intake or well to contamination.
Second, the vulnerability of the surface water intake or well was determined using a decision making chart developed in Delaware’s source water plan. Vulnerability was defined as the relative ease with which contaminants, if released within a source water area, could move and enter a public water supply well or intake at concentrations of concern.
3. Identify existing and potential sources of contamination in the source water area.
Third, an inventory of all documented existing and potential sources of contamination from discrete sources within these delineated areas were developed. The land use within these areas was also assessed for potential non-point sources of pollution.
4. Determine the susceptibility of the source water area to contamination.
This last step examined water quality test data from the previous 10 years. This sampling data was supplemented by water quality tests that were conducted in August 2001 by the State as part of a special water quality investigation of drinking water supplies. All of this information was evaluated and distilled into a ranking of susceptibility based on the methodology and matrix developed by the SWAPP Citizen and Technical Advisory Committee.
Susceptibility was reported for eight categories of contaminants, as follows:
Nutrients (nitrate, etc.)
Pathogens (bacteria, cryptosporidium, giardia, etc.)
Petroleum Hydrocarbons (benzene, toluene, etc.)
Pesticides (endrin, lindane, etc.)
Polychlorinated biphenyls (PCBs)
Other Organics (chloroform, etc.)
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Metals (lead, copper, zinc, etc.)
Other Inorganics (chloride, sodium, etc.)
The methods used for the assessment are outlined in the DNREC or Pennsylvania Department of Environmental Protection’s (DEP) approved SWAP program, approved by USEPA in March 2000.
The original Source Water Assessment Report for the City of Wilmington, Delaware public water supply intake on the Brandywine Creek was prepared by the University of Delaware, Institute for Public Administration – Water Resources Agency (UDWRA) by contractual agreement with the Delaware Department of Natural Resources and Environmental Control (DNREC), Division of Water Resources. The UDWRA prepared the report utilizing best professional judgment in accordance with methodology established in the October 1999 State of Delaware Source Water Assessment Plan and supplemented by the policies prescribed by the DNREC with concurrence by the SWAPP Citizen and Technical Advisory Committee. The SWAPP assessment was prepared by Martin Wollaston and Jerry Kauffman, assisted by the following UDWRA staff and students: Nicole Minni, Vern Svatos, Justin Bower, Scott Smizik, Martha Corrozi, and Arthur Jenkins. Copies of this report are available from DNREC.
1.3. Key Findings of Source Water Assessments
The findings of the original source water assessment were the first step in understanding Wilmington’s water supply and were considered appropriate and helpful within the boundaries of the intended purpose of the assessments. Given this preliminary nature, the application of the findings to Source Water Protection Planning efforts are limited. First, it provided high, very high, and exceeds standards susceptibility rankings for all the contaminant groups solely based on the presence and levels of various contaminants in the source water. The assessment did not take into account the ability of the removal of the treatment process, proximity of sources, or magnitude. Also, the assessment only accounted for 196 square miles of the 325 square mile watershed or roughly 60% of the watershed. The intent at the time of the assessment was that information from the upstream water intake source water assessments in West Chester and Coatesville in PA would be incorporated at a later period. However, this did not occur and major sources in Coatesville, Downingtown, West Chester and upstream of those areas were not included in the assessment. It was assumed that the intakes for those areas would take appropriate action to address local contaminant issues that would benefit Wilmington downstream. However, the actions resulting from the Source Water Assessments have been limited since there is no mandate or funding for water suppliers to address findings in the Source Water Assessments. Therefore, 90% of the drainage area for Wilmington’s water supply depends upon the actions of upstream communities in another state and three upstream water suppliers. High ranking point sources from the SWAP are shown in Table 1-1 below.
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Table 1-1 – High Ranking Point Sources Identified in 1999 SWAP
Source Type State Contaminants
Greenville Country
Club
NPDES DE Pathogens Other Organics
Winterthur NPDES DE Pathogens Other Organics
Hagley Museum
US Tank DE Petroleum Other Organics
Texaco Service Sta.
US Tank DE Petroleum Other Organics
The four sources above were the only high ranking sources of the 257 point sources identified upstream. The Christina Watershed Action Strategy identified 433 point sources upstream of the Wilmington intake. This means there were 176 additional point sources that were unaccounted for or ranked in the Source Water Assessment by DNREC. Also, these four top priority point sources were not field verified, nor were there performance, discharge violations, stream impacts, etc. A comparison of the top point sources to stream and intake water quality or other related studies and information to corroborate their current or potential impact was not conducted.
The top priority source types and issues from other SWAP reports upstream and other relevant watershed plans were compared with the Wilmington SWAP report (Table 1-2). The limits of the SWAP report are apparent when compared to the Wilmington WQ data and other studies (Table 1-3). As shown in Table 1-2, sources from wastewater, agriculture, transportation, and stormwater runoff are the greatest common concerns including riparian buffer loss. One study actually prioritized and ranked the importance of various subbasins within the Brandywine for action (Table 1-4). These priorities, priority areas and recommended actions and related ongoing initiatives in the Brandywine Watershed will need to be evaluated in the SWP Plan to determine if they will address the specific source related potential impacts at the Wilmington intake.
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Table 1-2 – Comparison of Summary of Top Priority Point Sources & Issues from Previous SWAP and Watershed Studies
Priority Source Type / Issue
Wilmington SWAP - DNREC
Ingram Mills
Downing-town Coatesville
303d list
Brandy-wine
Action Plan
Christina Tributary
Action Team
Chester County
Compendium Wilmington
WQ Data Total
transportation 1 1 1 1 1 1 6
wastewater 1 1 1 1 1 1 1 7
agriculture 1 1 1 1 1 1 1 7
auto & heavy equipment 1 1 1 1 4
recreational 1 1 2
reservoir releases 1 1 2
urban/suburban runoff 1 1 1 1 1 1 1 7
Superfund Sites 1 1
Riparian buffer loss/development 1 1 1 1 1 1 6
Taste & Odor compounds 1 1 2
Golf Courses 1 1 1 3
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Table 1-3 – Summary of SWAP Report Characteristics
Utility COW Aqua PA Downingtown
MWA PA American
Intake Wilmington
SWAP Ingram
Mills Fern Hill E. Branch
Brandywine W.
Branch Rock Run
Regulator DNREC PADEP PADEP PADEP PADEP PADEP
Assessor U of D WRA SSM SSM SSM SSM SSM
Drainage Area 319 113 2.7 64 32 6
Branch Main stem E. Branch E. Branch E. Branch W.
Branch Rock Run
Tributary Main stem E. Branch
E. Br. Chester Creek E. Branch
W. Branch
Rock Run
# of contributing tributaries all 12 1 7
Birch & 2 Log Run 2 UNT
# of municipalities 48 12 9 1
% Agriculture 37 50 18 62 68 64
% Forest 40 35 5 32 30 18
% Urban/Built 23 13 70 4 2 16
% Other 0 2 7 2 0 2
# of point sources
inventoried 257/433 325 NA 70 40 NA
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Table 3 – Summary of Priority Subbasins from Chester County Compendium
Water Quality General Water Quality (303d) Stormwater Stream Preservation Groundwater
Subbasin Priority Subbasin Priority Subbasin Priority Subbasin Priority Subbasin Priority
West Valley 1 Wilmington 1 Wilmington 1 West Valley 1 West Valley 1
Sucker
Run/Rock Run 2 West Valley 2 West Valley 2
Beaver
Creek 2
Beaver
Creek 2
Wilmington 3 Doe Run 3
Above
Chadds Ford 3
Pocopson
Creek 3 Wilmington 3
Marsh Creek 4
Marsh
Creek 4
Beaver
Creek 4
Marsh
Creek 4
Pocopson
Creek 4
Beaver Creek 5
Above
Chadds
Ford 5
Pocopson
Creek 5
Sucker
Run/Rock
Run 5
Marsh
Creek 5
Shamona Creek 6 Buck Run 6 Broad Run 6
Shamona
Creek 6
Above
Chadds
Ford 6
Upper West
Branch 7
Sucker
Run/Rock
Run 7 Marsh Creek 7
Above
Chadds
Ford 7
Sucker
Run/Rock
Run 7
Above Chadds
Ford 8
Upper West
Branch 8 Taylor Run 8
Upper East
Branch 8
Shamona
Creek 8
Broad Run 9 Broad Run 9
Below
Chadds Ford 9 Broad Run 9 Taylor Run 9
Upper East
Branch 10
Beaver
Creek 10
Sucker
Run/Rock
Run 10
Below
Chadds
Ford 10 Broad Run 10
Pocopson
Creek 11 Taylor Run 11
Upper East
Branch 11 Taylor Run 11
Upper West
Branch 11
Below Chadds
Ford 12
Shamona
Creek 12 Buck Run 12 Doe Run 12
Upper East
Branch 12
Taylor Run 13
Below
Chadds
Ford 13
Upper West
Branch 13 Buck Run 13
Below
Chadds
Ford 13
Buck Run 14
Upper East
Branch 14
Shamona
Creek 14 Wilmington 14 Buck Run 14
Doe Run 15
Pocopson
Creek 15 Doe Run 15
Upper West
Branch 15 Doe Run 15
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1.4. Relating the Source Water Assessments to the Protection Plan
This protection plan builds on the results of the source water assessments. It reassesses the inventory of sources and priorities based on their potential drinking water impact and refines previous contaminant based rankings based on pollutants of primary concern. This information is then utilized to develop a specific plan of actions to resolve current and future drinking water issues that can be used by water suppliers, regulators, or other watershed stakeholders.
1.5. Other Data Informing the Protection Plan
There are over 30 different water quality, water quantity, watershed characterization, watershed planning, and land use planning related studies and reports that have been conducted for the Brandywine Creek watershed or portions of it. Most of these studies have been influenced by the 303d impairment listings for the Clean Water Act. According to these studies agriculture and urban runoff/development are the biggest causes of impairment to the watershed.
The priorities and recommendations of the other studies will be examined and compared to the drinking water priorities in this plan in order to provide a comprehensive approach to improving the Brandywine Creek. By addressing priorities and sources that impact multiple watershed needs (water supply, aquatic life, recreation) the potential for successful efforts is greater than if they are pursued separately.
1.6. Implementing Projects Outlined in the Protection Plan
There are three levels of activity needed to successfully implement the protection plan. First, there are projects and initiatives that need to be undertaken by the City of Wilmington that are oriented towards protection of the water supply in the areas within the City of Wilmington along the Lower Brandywine Creek. These efforts include the adoption and enforcement of the Source Water Protection Ordinance. Second, the City of Wilmington will need to participate or lead specific initiatives that are being coordinated in the Christina River and Brandywine Creeks through the Christina Basin Water Quality Committee and Tributary Action Teams. These efforts will focus on helping to affect changes in regulatory policies and priorities as well as funding priorities from grants and government agencies (including USDA) that will also address Wilmington’s drinking water issue. Third, specific partnerships will need to be developed to support and coordinate efforts with specific stakeholders to preserve critical lands, to influence positive land use management and growth in Chester County, and continue support and enforcement of ordinances and land controls in New Castle County.
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2. Section 2 - Watershed Description, Characterization, & Analysis
2.1. Watershed & Surface Water intakes
2.1.1. General Overview
The Brandywine Creek watershed drains 325 square miles and includes two states, Delaware and Pennsylvania, and three counties (University of Delaware, 2002) (See Table 2-1). It consists of fifteen subbasins and flows into the Christina River at Wilmington, Delaware. All together, there are 48 municipalities in the two states that are either fully or partially within the Christina watershed. The Brandywine Creek is part of the Christina River Basin, which flows into the Delaware River at Wilmington, Delaware (Chester County Water Resources Authority, 2002).
Table 2-1 – State Land Area within the Brandywine Creek Watershed
Watershed PA DE MD Subtotal
Brandywine Creek 300.14 24.58 0 324.72
% of area 92 8 0 100
Source: PADEP, 2003
The headwaters of Brandywine Creek are in Chester County, PA, and the stream flows south into New Castle County, Delaware, where it is tributary to the Christina River (Figure 2-1, Table 2-3a). A small area in the easternmost part of the basin is in Delaware County, PA. The largest population centers in the watershed are the City of Wilmington, Delaware, and the boroughs of Downingtown, Coatesville, and West Chester, PA (Figure 2-2). According to PADEP (PADEP, 2003), a total of 372 streams flow for 536 miles in the Brandywine Creek Watershed of which over 50% are first order stream miles. Roughly 20% of the stream miles are impaired in the Brandywine Watershed and with future population growth these impairments may increase without additional management. Table 2-2 provides a summary
of the general major watershed characteristics.
In 1995, 37% of the Brandywine Creek watershed, including the portion in the State of Delaware was in agricultural land use. In Chester County, the majority of the farms were
dairy operations, with cash crops and livestock the 2nd
and 3rd
most common agricultural use. Sixty-five percent of the farms had conservation plans. The upper East Branch and West Branch, Doe Run, Buck Run, and the lower West Branch have the highest concentration of farms in the watershed.
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Table 2-2 – Summary of Brandywine Creek Watershed Characteristics
Land Area 325 sq.miles
1995 Land Use as % of Total Land Area
Agriculture 37 %
Developed 26 %
Other 37 %
Total Stream Miles 567 miles
1st Order Stream Miles 315 miles
% 1st Order Stream Miles 55 %
Impaired Stream Miles 140 miles
% Impaired Stream Miles 20 %
1998 Estimated Population 220,700 persons
2020 Projected Population 281,000 persons
% Population Increase by 2020 27 %
1998 Estimated Withdrawals (permitted) 19,463 MGY
1998 Estimated Withdrawals (permitted) 53.3 MGD
1998 Population on Public Water 62 %
Predominant Geology Crystalline
Source: Chester County Water Resources Authority, 2002
The Brandywine Creek is the source of drinking water for approximately 205,500 people used by five different water suppliers throughout the watershed (Table 2-3). The communities served by these suppliers depend on the quantity and quality of the Brandywine for current and future economic stability and growth.
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Table 2-3 – Major Water Supplies and Population Served by the Brandywine Creek
Water System Population
Served
Wilmington 140,000
PAWC Coatesville 18,000
Downingtown Authority 10,000
Aqua PA Ingrams Mill 29,000
Honey Brook Borough 2,500
Total 199,500
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Figure 2-1 – Streams and Drainage of the Brandywine Creek Watershed
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Table 2-3a – Streams and Drainage of the Brandywine Creek Watershed
Related Subshed **
EPA ID EPA/USGS TMDL Subshed Description CCWRAID Christina ID
BVA SOW ID
CCWRA description (from compendium maps)
BVA SOW description (From State of Watershed Reports)
1 WBr Brandywine to gage nr Honey Brook B12 B1 A1
Upper West Branch Brandywine Creek
Upper West Branch at Honey Brook
2 WBr Brandywine to Birch Run confluence B12 B2 A1
Upper West Branch Brandywine Creek
Upper West Branch at Honey Brook
3 WBr Brandywine above Rock Run B14 B2 A2/A3
West Branch Brandywine Creek/Rock Run/Sucker Run
Upper W. Branch at Coatesville/Hibernia
4 WBr Brandywine to gage at Coatesville B14 B3 A2/A3
West Branch Brandywine Creek/Rock Run/Sucker Run
Upper W. Branch at Coatesville/Hibernia
5 WBr Brandywine to gage at Modena B14 B3 A2/A3
West Branch Brandywine Creek/Rock Run/Sucker Run
Upper W. Branch at Coatesville/Hibernia
6 WBr Brandywine to Buck Run confluence B14 B4 A2/A3
West Branch Brandywine Creek/Rock Run/Sucker Run
Upper W. Branch at Coatesville/Hibernia
7 WBr Brandywine to Broad Run confluence B13 B4 A7/A4
West Branch Brandywine Creek/Broad Run
Broad Creek / Lower W. Branch at Embreeville
8 WBr Brandywine to Wawaset B13 B4 A7/A4 West Branch Brandywine Creek/Broad Run
Broad Creek / Lower W. Branch at Embreeville
9 Upper EBr Brandywine Creek B11 B8 B8 Upper East Branch Brandywine Creek Upper East Branch at Struble Lake
10 EBr Brandywine to Marsh Creek B7 B8 B8/B9 East Branch Brandywine Creek/Shamona Creek
Upper E. Branch at Shamona Creek
11 EBr Brandywine to gage nr Downingtown B7 B9 B8/B9
East Branch Brandywine Creek/Shamona Creek
Upper E. Branch at Shamona Creek
12 EBr Brandywine to Beaver Creek B9 B12 B12 East Branch Brandywine Creek/Beaver Creek Beaver Creek
13 EBr Brandywine to gage below Dowingtown B9 B10 B12
East Branch Brandywine Creek/Beaver Creek Beaver Creek
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Related Subshed **
EPA ID EPA/USGS TMDL Subshed Description CCWRAID Christina ID
BVA SOW ID
CCWRA description (from compendium maps)
BVA SOW description (From State of Watershed Reports)
14 EBr Brandywine to Wawaset B8 B10 B10 East Branch Brandywine Creek/Taylor Run Lower East Branch
15 Main stem Brandywine to Pocopson confluence B4 B14 C14/C15
Brandywine Creek/Pocopson Creek
Pocopson Creek / Main stem Above Chadds Ford
16 Main stem Brandywine to Chadds Ford gage B1 B14 C14
Brandywine Creek above Chadds Ford Main stem above Chadds Ford
17 Main stem Brandywine to Smiths Bridge B3 B16 C16
Brandywine Creek below Chadds Ford Main stem below Chadds Ford
18 Main stem Brandywine to Rockland Rd. Bridge B3 B16 C16
Brandywine Creek below Chadds Ford Main stem below Chadds Ford
19 Main stem Brandywine to gage at Wilmington B3 B16 C16
Brandywine Creek below Chadds Ford Main stem below Chadds Ford
20 Buck Run to Doe Run confluence B5 B5 A5 Buck Run Buck Run
21 Doe Run to gage near Springdell B6 B6 A6 Doe Run Doe Run
22 Doe Run to Buck Run confluence B6 B6 A6 Doe Run Doe Run
23 Buck Run tributary B5 B5 A5 Buck Run Buck Run
24 Little Broad Run to gage nr Marshallton B13 B7 A7/A4
West Branch Brandywine Creek/Broad Run
Broad Creek / Lower W. Branch at Embreeville
25 Broad Run tributary B13 B7 A7/A4 West Branch Brandywine Creek/Broad Run
Broad Creek / Lower W. Branch at Embreeville
26 Marsh Creek to gage nr Glenmoore B10 B11 B11 Marsh Creek Marsh Creek
27 Lower Marsh Creek B10 B11 B11 Marsh Creek Marsh Creek
28 Unnamed trib. to Valley Creek B15 B13 B13 West Valley Creek Valley Creek / W. Valley Creek
29 West Valley Creek tributary B15 B13 B13 West Valley Creek Valley Creek / W. Valley Creek
30 Beaver Creek tributary B9 B12 B12 East Branch Brandywine Creek/Beaver Creek Beaver Creek
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Related Subshed **
EPA ID EPA/USGS TMDL Subshed Description CCWRAID Christina ID
BVA SOW ID
CCWRA description (from compendium maps)
BVA SOW description (From State of Watershed Reports)
31 Pocopson Creek tributary B4 B15 C14/C15 Brandywine Creek/Pocopson Creek
Pocopson Creek / Main stem Above Chadds Ford
32 Birch Run tributary (Chambers Lake) B12 B1 A1
Upper West Branch Brandywine Creek
Upper West Branch at Honey Brook
33 Rock Run tributary B14 B2 A2/A3 West Branch Brandywine Creek/Rock Run/Sucker Run
Upper W. Branch at Coatesville/Hibernia
34 Main stem Brandywine to Christina confluence B2 B17 C17
Brandywine Creek at Wilmington Main stem through Wilmington
35 Upper Marsh Creek B10 B8 B11 Marsh Creek Marsh Creek
** Note that the subsheds from EPA/USGS are smaller subshed areas than that used by CCWRA, University of Delaware, or BVA, thus the related subsheds are larger areas and not necessarily the same hydrologic boundaries and could incorporate multiple EPA subsheds. An EPA subshed may fall within two different CCWRA, BVA, or Christina subsheds depending on how they were created. A direct comparison or translation of information from non-EPA/USGS subsheds is not possible and any information from different subsheds must be evaluated within that system only.
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Figure 2-2 – Municipalities of the Brandywine Creek Watershed
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2.1.2. Physiography and Geology
The geology of the Brandywine watershed is rooted in the central Appalachian Piedmont physiographic province of southeastern Pennsylvania and northern Delaware. The Piedmont, in its most basic definition, means foothills. These are the foothills to the Appalachian Mountains, a mountain range that originated in North America between 545 and 250 million years ago (M.A.). The Brandywine watershed lies primarily in the Piedmont Upland section of the province; however a thin band of piedmont lowland section, stretching from Parkesburg to West Whiteland Township nearly bisects it (Fig. 2-3).
Current studies indicate that the geology of the central Appalachian Piedmont preserves a record of plate tectonic convergence that includes subduction-related arc magmatism, arc-continent accretion, post-accretion magmatism and coincident low- to moderate-pressure high-temperature metamorphism, and regional metamorphism at moderate to deep levels resulting from crustal thickening during subsequent plate convergence (Bosbyshell, 2001). This means that there have been episodes where oceanic crust containing volcanic islands slid into what is now the present day North American continent (Plank et al, 1998). Over time the sediments from the island arc joined with those sediments from the colliding continent. During this process and later stages of continental collision magma was generated and moved upward through fissures creating some of the igneous bodies in the region. Later periods of continent-continent collision created additional folding and faulting of the many sedimentary layers in the region and contributed to the uplift of the Appalachian Mountains (Figure 2-4). These episodes of folding and faulting and the compression forces due to continental collisions have led to the many metamorphic rock types (quartzite, gneiss, marble, etc) observed in the region.
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Figure 2-3: Physiography and Geology of the Brandywine Creek Watershed, Pennsylvania and Delaware
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Figure 2-4: Cross section showing sequence of events related to the emplacement of rock types found in the mid-Atlantic Piedmont Province. (A) 543 million years ago, active volcano is offshore; (B) 500 million years ago, volcano and pile of sediments scraped off the subducting slab are larger than in (A); and (C) 440 million years ago, collision between the volcanic islands and the ancient continent has formed a tall mountain range. From Plank, M.O. and Schenck, W.S., 1998.
The headwaters of both the East and West Branches of the Brandywine Creek occur in the Piedmont Upland Province near Honey Brook in northwestern Chester County. As the branches flow east and south they flow across the crystalline rocks of the Honey Brook Massif, a large body of mostly metamorphosed granites and amphiboles overlain by a basalt-rhyolite sequence of volcanic rocks (Sloto, 1994). Adjacent to the Honey Brook Massif to the south is the Mine Ridge Massif. This is a body of amphibolites, felsic/mafic gneisses, metadiabases, and ultramafites closely mixed with each other throughout the formation.
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Figures 2-5a&b: Geologic features of the Piedmont Upland province.. From Crawford et al, 1999.
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As the waters continue to flow south and east they enter the Chester Valley and, in doing so, the Piedmont Lowland Province (Figures 2-5a&b). This is a narrow terrain that cuts across the center of the watershed from southwest to northeast in a band that trends through Parkesburg, Coatesville and Downingtown. This area is underlain by Cambrian and Ordovician (542-444 M.A.) limestones and dolomites as well as a bottom layer of quartzite that also appear north of the Chester Valley and west of the Honey Brook Massif (Sloto, 1994). These rocks were deposited in a marine environment associated with continental margin sedimentation during a time when this region was the eastern boundary of the North American continent. The quartzites of this region are very durable and form the distinct hills that are encountered. The limestones and dolomites are more susceptible to erosion from weather and flowing surface/ground waters. The Elbrook Limestone, for example, forms the low hills in the Chester Valley section of the Piedmont Lowlands (Sloto, 1994).
Flowing out of the Chester Valley, the waters once again enter the Piedmont Upland province on their way to their confluence southwest of West Chester. This section contains the Baltimore Gneiss and the Glenarm Group, a series of geologic units comprised of the Setters Quartzite, Cockeysville Marble, and the Glenarm Wissahickon formations. The Baltimore Gneiss is most likely the oldest rock in the mid-Atlantic Piedmont. These billion year old rocks support the hills of southeastern Chester County and northern New Castle County. They form the core of the Woodville Nappe, the Mill Creek Nappe, and the Avondale anticline. These are just a few of the dome-like structures that crop out in a belt stretching between Baltimore, Maryland and Philadelphia, Pennsylvania (Plank and Schenck, 1998).
After the east and west branches combine they flow south across the rocks of the Glenarm Group, across the Avondale Anticline section of the Baltimore Gneiss, and into the Mt. Cuba Wissahickon Formation. Sediments that became the Glenarm Group (Setters Quartzite, Cockeysville Marble, Glenarm Wissahickon Formations), and the Mt. Cuba Wissahickon Formation were deposited in marine rift basins floored by continental crust which is represented by the Baltimore Gneiss (Blackmer, 2005). The Mt. Cuba Wissahickon Formation forms the dominant rock type in the far southeastern Pennsylvania and Delaware Piedmont and may be as much as 8,000 feet thick due to numerous episodes of folding and faulting according to Thompson (1976). This formation is less resistant to chemical and physical weathering than the adjacent Wilmington Complex to the south and east. Thus, deeply incised stream valleys and steep slopes characterize this portion of the watershed. Amphibolites and gneisses of the Wissahickon support ridges while mica schists erode to form deep-sided valleys (Plank and Schenck, 1998).
The creek then crosses the formations of the Wilmington Complex prior to being withdrawn by the City of Wilmington. These Formations are comprised of mostly hard mafic and felsic gneisses and amphibolites that are primarily visible at the surface in the form of rounded boulders. The rocks of the Wilmington Complex form the gentle rolling hills of north Wilmington and its suburbs (Plank and Schenck, 1998).
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2.1.3. Soils
The Brandywine Watershed has different soils types that have varying ranges of permeability and drainage which affect groundwater recharge, erodability, and stormwater runoff. The permeability of soils are dependent on the type (sand, silt or clay) and hydrologic soil group A,B,C,D. Soils are used to delineate floodplains, identify fragile erosion prone slopes and define septic system limitations. Generally silts and clays are less permeable, generate greater stormwater runoff, and sustain greater sediment loads. In contrast, sands and gravels provide greater groundwater recharge and less runoff and sediment loads (Bowers, 1998).
As shown in Figure 2-6, the majority of the soil associations in watershed of the Glenelg–Manor–Chester groups. The middle band of soils in the watershed is limestone. Small localized areas along the edges of the upper West Branch and the lower East Branch in PA are Neshaminy-Glenelg. There are some minor amounts of Edgemont in the upper watershed. There is one small patch of Neshaminy-Chrome-Conowingo near West Chester on the edge of the watershed boundary. There is Neshaminy-Talleyville-Urban land association and Elsinboro-Delanco-Urban land in the Delaware part of the watershed about halfway between Chadds Ford and the Wilmington intake. The characteristics of these soils are provided in Table 2-4.
Most of the development in the middle band of the watershed (Coatesville, Downingtown, and the Route 30 corridor) also coincides with the Hagerstown Conestoga Guthrie soils with low permeability. Thus development of this corridor in a limestone area with low permeability makes the traditional infiltration techniques for stormwater management difficult or not applicable. This clearly shows the conflict between the focused past and future growth of the watershed and its natural characteristics.
The Soil Conservation Service also classified soils into hydrologic groups to indicate the minimum rate of infiltration obtained for bare soil after prolonged wetting. The groups, which are A, B, C, and D, are also used in determining runoff curve numbers. The soil types in the Brandywine Creek watershed are classified as B, C, and D soils, but the majority of the soils are type B soils.
Group B soils have moderate infiltration rates when thoroughly wetted and consist chiefly of moderately deep to deep, moderately well to well drained soils with moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission (0.15- 0.30 in/hr).
Group C soils have low infiltration rates when thoroughly wetted and consist chiefly of soils with a layer that impedes downward movement of water and soils with moderately fine to fine texture. These soils have a low rate of water transmission (0.05-0.15 in/hr).
Group D soils have high runoff potential. They have very low infiltration rates when thoroughly wetted and consist chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a clay pan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very low rate of water transmission (0-0.05 in/hr).
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Figure 2-6 – Brandywine Creek Watershed Soils (source: Keorkle and Senior, 2002)
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Table 2-4 – Soils of the Brandywine Creek Watershed
MAP
ID
Desig-
nation
Soil
Association Description
Depth to
Bed-rock
Depth to
Groundwat
er Table
(ft)
SCS
Hydrologic
Soil Group
(A, B, C, or D)
Permeability
(in/hr)
Soil Type (sand,
loam, clay)
1 GMC
Glenelg -
Manor -
Chester
Nearly level to steep, well-drained, medium-
textured soils formed over micaceous
crystalline rocks; on uplands 2-7 5+ B 0.63 - 2.0 loam, silt loam
2 E Edgemont
Moderately deep, channery soils on grayish
quartzite and phyllite 2-6 5+ B 0.63 - 2.0 channery loam
3 HCG
Hagerstown -
Conestoga -
Guthrie Deep, silty soils on limestone 3-6 B/C/D C,B,D < 0.2 silt loam
4 NG
Neshaminy -
Glenelg
Moderately deep and deep, well drained,
silty, channery, and gravelly soils on gabbro
and granodiorite 3-6 5+ B 0.63 - 2.0 gravelly silt loam
5 NCC
Neshaminy -
Chrome -
Conowingo
Moderately deep and deep, silty soils on
serpentine 1-6 2-5 B/C 0.63 - 2.0
gravelly silt loam
gravelly silty clay
loam
6 NAW
Neshaminy -
Aldino -
Watchung
Level to steep, well drained, moderately well
drained, and poorly drained, medium-
textured soils formed over dark colored
gabboric rocks on uplands 4-10 0-4 B/C/D < 0.2 silt loam
7 NTU
Neshaminy -
Talleyville -
Urban
Level to moderately sloping, well-drained,
medium-texture soils, relatively undisturbed
to severely disturbed; fored over dark colored
gabbroic rocks; on uplands 6-10 4-6 B 0.63 - 2.0 silt loam
8 EDU
Elsinboro -
Delance -
Urban
Level to gently sloping, well drained and
moderately well drained, medium-textured
soils, relatively undisturbed to severely
disturbed; formed on old alluvium on stream
terraces 6 -20 2-5 B/C 0.63 - 2.0 silt loam
Source: Appendix D, Phase III Report, - Bowers, 1999
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2.1.4. Hydrology
The Brandywine Creek Watershed currently has a humid continental climate. Average yearly precipitation is about 43 in. with summer and winter mean temperatures of about 24 and 0 °C, respectively. Prevailing winds are westerly during the winter and southerly during the summer. Weather systems that affect the area generally originate in the central United States and move eastward over the Appalachians. Periodically, moist northward moving weather systems bring moderate and heavy precipitation to the area. It is important to note however that based on low and high emission models for climate change the climate is expected to change to be more similar to either Southern Virginia or Georgia by 2100 (Union of Concerned Scientists, 2008). Therefore, current climatological, meteorological, and hydrological analyses of past and current data may not be the appropriate predictors of future systems by 2100.
The water budget for the Brandywine Creek Watershed is dependent upon the geology, rainfall patterns during the period of record, topographic features such as slope, soils, and degree of development and impervious cover. The USGS prepared the water budgets for Brandywine Creek watershed in the Chester County Compendium (Chester County Water Resources Authority, 2001). Because average water budgets are calculated by averaging each component over the period of record, the results are often not additive to the total average annual precipitation. The average water budget components calculated by USGS for Brandywine Creek watershed by USGS shows that approximately 16% of the annual precipitation is lost to runoff in the watershed (Table 2-5).
Table 2-5 – Water Budget for the Brandywine Creek Watershed
Water Budget Element inches/yr
Runoff 7.2
Evapotranspiration 25.9
Baseflow 12.8
Recharge 14.8
Precipitation 45.9
Source: Chester County Water Resources Authority, 2001
Though the water budget provides an overall idea of the hydrologic cycle, the daily observation of this is through flow in the Brandywine Creek. Analysis of the flow in the watershed provides a more specific description of its behavior during runoff and baseflow
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periods. Long-term historical data were examined in order to gauge the natural variation in climate and geology. Data was collected from the USGS gauge station network and Delaware rain gauge network. In the Brandywine Creek above Wilmington watershed in Delaware and Pennsylvania, the record low daily mean streamflow during drought dropped 35 percent, from 102 million liters per day in 1966 to 76 million liters per day in 2002 (Kauffman, 2006).
Figure 2-7 shows the average annual flow from 1972 to 2006 at Chadds Ford and Wilmington. The Wilmington gauge has an additional 27 square miles of drainage as compared to Chadds Ford and should have a greater annual flow. However, during extremely wet years (1996 and 2003) and the drought of record (2002) the Chadds Ford gauge registered a greater average annual flow than the Wilmington gauge station demonstrating the dominance of the flow contribution in the Pennsylvania part of the watershed (See Figure 2-8).
Precipitation can vary from 33.9 to 66.9 inches per year with an average of 46.5 inches per year based on rain gauge data from the Porter Reservoir from 1946 to 2006 (Figure 2-9). Monthly rainfall can range from 4.8 to 14.9 inches per month with an average of 7.9 inches per month (Table 2-6). Monthly maximum rainfall in Figure 2-9 shows that between 6 and 14 inches of rain can fall monthly. Annual rainfall can deviate by -13 to +22 inches per year from the annual average (Figure 2-11). As shown, there appears to be an increase in the extremes in annual precipitation and a potential upward trend in annual precipitation since 1970. Further analysis would need to be conducted to determine if this trend is real. As shown in Figure 2-11 there is a wide variation in annual flow from year to year (a factor of 2.5) depending upon the precipitation patterns. The comparison of annual flow to deviation in annual precipitation seems to provide a better indication of the severity of annual flow changes than total annual precipitation (Figure 2-12). Looking at the annual deviations in flow and precipitation combined suggests that an extremely dry year can lead to lower than normal flows the following year. However, the data also suggests that wetter than normal years do not lead to higher than normal flows in any following years. This suggests that wetter years do not seem to provide insurance against lower flows in subsequent years especially if there is a significant lack of rainfall.
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Annual flow (cfs)
0
100
200
300
400
500
600
700
800
900
1000
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
Year
Flo
w
Figure 2-7 – Average Annual Flow at Chadds Ford 1974 to 2007
Table 2-6 – Summary of Rainfall for the Brandywine Creek Watershed at Porter WTP (1948 – 2004)
Parameter Annual rainfall
(in) Monthly rainfall
(in)
avg 46.2 7.9
max 68.9 14.9
min 33.6 4.8
stdev 8.4 2.2
90%tile 57.4 10.7
# 55 56
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Comparison of Average Annual Brandywine Creek Flow at Chadds Ford and
Wilmington
0
100
200
300
400
500
600
700
800
900
1000
19
72
19
73
19
74
19
75
19
76
19
77
19
78
19
79
19
80
19
81
19
82
19
83
19
84
19
85
19
86
19
87
19
88
19
89
19
90
19
91
19
92
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
Year
Flo
w
Chadds Ford f low (cfs)
Wilmington Flow (cfs)
Figure 2-8 – Comparison of Avg. Annual Brandywine Creek Flow between Wilmington and Chadd Ford
Total Annual rainfall (in) Porter Reservoir 1948-2004
0
10
20
30
40
50
60
70
80
19
46
19
48
19
50
19
52
19
54
19
56
19
58
19
60
19
62
19
64
19
66
19
68
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
Total Annual rainfall (in)
Figure 2-9 – Average Annual Rainfall at Porter WTP 1948 to 2004
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max monthly (in)
0
2
4
6
8
10
12
14
161
94
61
94
81
95
01
95
21
95
41
95
61
95
81
96
01
96
21
96
41
96
61
96
81
97
01
97
21
97
41
97
61
97
81
98
01
98
21
98
41
98
61
98
81
99
01
99
21
99
41
99
61
99
82
00
02
00
22
00
42
00
62
00
8
max monthly (in)
Figure 2-10 – Maximum Monthly Rainfall at Porter 1948 - 2004
-15
-10
-5
0
5
10
15
20
25
19
46
19
48
19
50
19
52
19
54
19
56
19
58
19
60
19
62
19
64
19
66
19
68
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
Year
Av
g.
An
nu
al
Pre
cip
De
via
tio
n (
in)
Figure 2-11 – Average Annual Rainfall Differences from Long Term Average Annual Rainfall 1948 to 2004
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Comparison of Average Annual Brandywine Creek Flow at Chadds Ford and
Wilmington
0
100
200
300
400
500
600
700
800
900
10001972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
Year
Flo
w
-20
-10
0
10
20
30
40
50
60
70
80
An
nu
al R
ain
fall (
in)
Chadds Ford f low (cfs)
Wilmington Flow (cfs)
Annual Rainfall (in)
annual deviation
Figure 2-12 – Comparison of Average Annual Brandywine Creek Flow and Average Annual Rainfall Deficit/Surplus
Extreme flow conditions can represent periods of greatest concern for water suppliers where water quality can be extremely affected. For example, since 1911 there have been 11 events where the flow exceeded 8,000 cfs at Chadds Ford (Table 2-7). Those events most likely lead to intake closures or water quality that was challenging to treat at the water facility.
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Table 2-7 – Detailed Summary of Extreme High Flow Events > 8,000 cfs
Years with
flow > 8,000
cfs Hurricane
Name
Years with flow >
8,000 cfs Hurricane
Name
Years with flow >
8,000 cfs Flow (cfs)
Hurricane Name
1920 NA 1972 Agnes 1999 Floyd
1933 NA 1978 10K 2000 >10,000
1979 2003 >10,000
2004 >10,000 Ivan/Jeanne
2006
Notes: 1971-1979 wet period
1993-2006 wet period
As shown by the previous figures, the cycles of lowest daily flows and highest flows appear to follow a 30 to 35 year cycle as seen in other regional climate analysis (Interlandi and Crockett, 2000). The lowest flows occurred during the 1930s and 1940s, 1960s, and late 1990’s into early 2000 (See Table 2-8 and Figure 2-13). 1971 to 1979 appears to be one of the periods with the greatest average daily flows. From 1959 to 1966 was the greatest period of consecutive years when the annual precipitation was below the average annual precipitation for Wilmington. This also coincided with one of the worst basinwide drought periods of record (> 200 year drought). Approximately 33 (60%) of the past 55 years between 1949 and 2003 were dryer than average and 22 (40% of the past 55 years were wetter than average. In the case of most of the wetter years of record, they can be associated with single significant named storm events. In 1999, Hurricane Floyd deposited record rainfall amounts in the region. In 1996, significant snowstorms dropped over 3 feet of snow in places in the Delaware Valley leading to snowmelt and baseflow elevation issues. In 1972 Hurricane Agnes came up the Susquehanna River Basin resulting in the flood of record which had residual effects on the adjacent Delaware River Basin.
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Bottom 1% of Mean Daily Flow - Chadds Ford 1911-
2007
0
10
20
30
40
50
60
70
80
1/0
/1900
9/2
6/1
902
6/2
2/1
905
3/1
8/1
908
12/1
3/1
910
9/8
/1913
6/4
/1916
3/1
/1919
11/2
5/1
921
8/2
1/1
924
5/1
8/1
927
2/1
1/1
930
11/7
/1932
8/4
/1935
4/3
0/1
938
1/2
4/1
941
10/2
1/1
943
7/1
7/1
946
4/1
2/1
949
1/7
/1952
10/3
/1954
6/2
9/1
957
3/2
5/1
960
12/2
0/1
962
9/1
5/1
965
6/1
1/1
968
3/8
/1971
12/2
/1973
8/2
8/1
976
5/2
5/1
979
2/1
8/1
982
11/1
4/1
984
8/1
1/1
987
5/7
/1990
1/3
1/1
993
10/2
8/1
995
7/2
4/1
998
4/1
9/2
001
1/1
4/2
004
10/1
0/2
006
7/6
/2009
Date
Me
an
Da
ily
Flo
w (
cfs
)
Figure 2-13 – Lowest Mean Daily Flows at Chadds Ford 1911 - 2007
Table 2-8 – Detailed Summary of Extreme Low Flow Events (< 70 cfs)
years with Flow < 70 cfs years with Flow < 70 cfs years with Flow < 70 cfs
1921 1963 1995
1930 1964 1999
1932 1966 2002
1941
1944
The flow response at various locations in the watershed is significant to examine potential runoff pollutant loadings. A detailed analysis of the average daily flow at a location can provide information on the frequency that a given average daily flow can occur. For example, as shown in Figure 2-14, the average daily flow at Chadds Ford from 1911 to 2007 is estimated to be 290 cfs, but ranges from 33 to 10,100 cfs. Eighty percent of the average daily flows occur between 121 and 765 cfs. Only 10% of the flows occur above and below those limits respectively.
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A summary of the flow related statistics at various locations in the watershed is provided in Table 2-9. The data shows some level of relationship with drainage area which has been defined in USGS studies, but does not show any apparent differences in flow due to impervious cover between various parts of the watershed produce apparently different annual flow statistics on a per area basis. However, the impact of different cover types may be more evident when examined on a daily basis.
Chadds Ford 1911-2007
1
10
100
1,000
10,000
100,000
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
% flow less than
avg
dail
y f
low
(cfs
)
Figure 2-14 – Cumulative Frequency of Flows at Chadds Ford
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Table 2-9 - Summary of Daily Flow Statistics at Various Locations in the Brandywine Creek Watershed
USGS Station
# Location/Description Drainage
Area (mi2) 10% 50%
(mean) 90% min max
1480300 West Branch Brandywine Creek near Honey Brook, PA
18.7 6.8 15 44 1 1620
1480400 Birch Run near Wagontown, PA
4.55 1.5 3.9 13 0.1 250
1480500 West Branch Brandywine Creek at Coatesville, PA
45.8 15 42 114 3 3400
1480617 West Branch Brandywine Creek at Modena, PA
55 26 57 150 7.4 4010
1480638 Broad Run at Northbrook, PA 6.39 3.7 9.6 23 1.7 277
1480675 Marsh Creek near Glenmoore, PA
8.57 2.1 7.8 26 0.21 444
1480685 Marsh Creek near Downingtown, PA
20.3 7 16 66 0.18 462
1480700 East Branch Brandywine Creek near Downingtown, PA
60.6 25 60 177 7.2 3220
1480870 East Branch Brandywine Creek below Downingtown,
PA 89.9 42 101 306 19 3040
1481000 Brandywine Creek at Chadds Ford, PA
287 122 284 758 33 10600
1481500 Brandywine Creek at Wilmington, DE
314 134 340 890 35 14300
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2.1.5. Reservoirs & Impoundments In The Watershed
Approximately nine major reservoirs are located within the watershed (Table 2-10). Some are owned and operated by individual water utilities and others are owned and operated by regional organizations such as the Chester County Water Resources Agency for both water supply and recreation. These reservoirs are used in two different ways. The reservoirs of Marsh Creek and Chambers Lake are multiple purpose reservoirs providing flood control, recreation, and water supply releases during extreme low flow periods. The Rock Run Reservoir and other utility owned reservoirs are designed for continuous direct withdrawal to meet daily demand from nearby water treatment facilities.
Releases from these reservoirs have been observed to have impacts on downstream water quality such as turbidity. Therefore, it is important to document the owners, operators, and operating principles behind these reservoirs.
Chambers Lake Reservoir / Hibernia Dam - Built by and is owned and operated by the Chester County Water Resources Authority (CCWRA) in partnership with the City of Coatesville Authority, the NRCS and other state and local sponsors. Its role in water supply was intended to solely serve as a supplemental source of replacement water to support water supply withdrawals when taken by CCA from the West Branch Brandywine Creek. The Chambers Lake Reservoir is used in “tandem” with the CCA owned Rock Run Reservoir during periods of extended dry weather and low stream flow. CCA withdraws water from both Rock Run and West Branch Brandywine Creek at pre-determined balances. A complicated series of “triggers” have been established to guide which source is to provide the majority of withdrawal. At certain points, the shift is switched between the Rock Run and West Branch Brandywine sources to insure that neither supporting reservoir is completely depleted and that both reservoirs are drawn down in a generally synchronized manner. Chambers Lake Reservoir was completed in 1994 and filled in 1995. It has been used to support CCA withdrawals during the droughts of 1997, 1998 and 1999. Chambers Lake is a 400 million gallon water supply reservoir that is used to provide water for the Coatesville regional water supply system during droughts. Hibernia Dam is of earthen construction. Its height is 64.5 feet with a length of 700 feet. Its capacity is 2016 acre feet. Normal storage is 1225 acre feet. It drains an area of 4.5 square miles. It has a normal surface area of 84.9 acres.
Struble Lake – Located on East Branch Brandywine Creek in Chester County, Pennsylvania, Struble Lake is used for flood control and recreation purposes. Construction was completed in 1971. It has a normal surface area of 146 acres. It is owned by Chester County Water Resources Authority. The dam is of earthen construction. Its height is 31 feet with a length of 1500 feet. Its capacity is 2880 acre feet. Normal storage is 1025 acre feet. It drains an area of 2.8 square miles.
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Table 2-10 – Summary of Reservoir Characteristics in the Brandywine Creek Watershed
Reservoir Purpose Owner Storage
(MG) Drainage
Area (mi2)
Surface Area
(acres)
capacity (acre feet)
normal capacity
(acre feet)
withdrawal draft
Chambers Lake/ Hibernia Dam water supply
CCWRA, CCA, NRCS 400 4.5 84.9 2016 1225 NA
Marsh Creek
flood control, water supply
and recreation DCNR 2 billion 20 525 24,000 6380 NA
Struble Lake
flood control and
recreation CCWRA,
CCA, NRCS 334 2.8 146 2880 1025 NA
Barneston Dam flood control CCWRA,
CCA, NRCS NA 11.9 NA 3700 NA NA
Beaver Creek Dam flood control CCWRA,
CCA, NRCS 14 3.1 11 1464 43 NA
Rock Run / Coatesville Reservoir water supply CCA 329 5.3 61 1250 1010
964 mg/yr withdrawal
draft
Hoopes Reservoir water supply COW 2 billion NA NA NA NA NA
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Marsh Creek Reservoir - (similar to Chambers Lake Reservoir) was designed to operate only during periods when stream flows in Brandywine Creek are at extreme lows. Both Marsh Creek and Chambers Lake reservoirs are required to begin releases to support downstream withdrawals when the stream gage at Chadds Ford reads at or below 140 cfs. This flow trigger was agreed to several years ago by water supply planners and agencies in Pennsylvania and Delaware to assure that the natural stream flow is maintained under dry weather conditions to support the surface water withdrawals taken by the City of Wilmington from the lower Brandywine Creek. The Marsh Creek reservoir is 525-acres, and provides flood control, water supply and recreation. It has a normal surface area of 535 acres. It is owned by DCNR - Bureau of State Parks. Construction of the dam was completed in 1973. The dam at Marsh Creek is of earthen construction, rock fill. Its height is 90 feet with a length of 990 feet. Its capacity is 24,000 acre feet (over 7 billon gallons). Normal storage is 6,380 acre feet. It drains an area of 20 square miles.
Barneston Dam - is located on East Branch Brandywine Creek in Chester County, Pennsylvania and is used for flood control purposes. Construction was completed in 1983. It is owned by Chester County Water Resources Authority. Barneston Dam is of earthen construction. Its height is 43 feet with a length of 1305 feet. Its capacity is 3700 acre feet. It drains an area of 11.9 square miles.
Beaver Creek Dam - located on Beaver Creek in Chester County, Pennsylvania and is used for flood control purposes. Construction was completed in 1975. It has a normal surface area of 11 acres. It is owned by Chester County Water Resources Authority. The dam is of earthen construction. Its height is 36 feet with a length of 1370 feet. Its capacity is 1464 acre feet. Normal storage is 43 acre feet. It drains an area of 3.1 square miles.
Rock Run / Coatesville Reservoir - Coatesville Reservoir is the result of Rock Run Dam on the Rock Run River in Chester County, Pennsylvania and is used for drinking water and recreation purposes. Construction was completed in 1917. It has a normal surface area of 61 acres. It is owned by Pennsylvania - American Water Company. Rock Run, dam is concrete, buttress supported. Its height is 42 feet with a length of 583 feet. Its capacity is 1250 acre feet. Normal storage is 1010 acre feet. It drains an area of 5.3 square miles. The current average daily withdrawal volume is approximately 964 mg/year.
Hoopes Reservoir - Owned by the City of Wilmington and was originally Delaware's only reserve storage reservoir. The total capacity is 2.0 billion gallons and the useable capacity is 1.8 billion gallons. The reservoir was built in 1932 and it is an off-stream pump storage impoundment. Raw water is pumped from the Brandywine Creek through a 4-mile pipeline to replenish the reservoir. The City releases water from the reservoir back to Wilmington or to the United Water Delaware water company usually only during drought or low flow periods in the summer when stream flows are low in the Brandywine, Red Clay, and White Clay Creeks. However, water can be released from Hoopes Reservoir during other times, for instance while the City intake canal is closed for cleaning or due to hazardous waste spills on the above creeks. The City’s water treatment plants are located in Wilmington, not at the reservoir, at the Brandywine and Porter Filter Plants (University of Delaware, 2002). The releases vary depending on the stream flows and emergencies that occur. During the drought of 1999, the City released 95 mg from Hoopes Reservoir, 10 mg to Wilmington and 85 mg to United Water Delaware (University of Delaware, 2002). During the drought of
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1995, Wilmington released 460 mg to the City and to United Water Delaware (University of Delaware, 2002).
2.1.6. First Order Streams
A first order stream, sometimes called a headwaters stream, is a stream that has no permanent tributaries. Therefore, this waterbody is the first section of the Brandywine Creek that will receive the impacts of land based activities and pollution. First order streams can provide important functions in maintaining baseflow, absorbing pollutants, and providing nursery areas and habitat for aquatic life. Given the important function and vulnerability of these streams to activities such as agriculture and development/urban runoff they must be given priority for protection.
A detailed analysis of first order streams is provided in the Chester County Watershed Compendium (Chester County Water Resources Authority, 2001). This information was examined to determine which areas have the most first order streams and related land area and then compared to land use to determine which areas may be more eligible for preservation, agricultural restoration, or urban restoration. Of the 567 stream miles in the watershed, 58% or 328 miles are first order streams. Over 55% of the land area within the Brandywine Creek watershed drains to first order streams.
The average miles of first order streams per drainage area for the entire Brandywine Creek is 1.01 miles of first order stream per square mile of drainage area (see Table 2-11). Approximately 8 of the 15 subbasins are above the watershed average. The remaining 7 are below the average. The range is from 0.35 miles/sq. mi. along the main stem Brandywine Creek at Wilmington to over 1.46 miles/sq. mi. along the Brandywine Creek at Chadds Ford. Though the highest ratio of 1st order stream miles to drainage area appears to be in the Lower Basin between Chadds Ford and Doe Run, this does not indicate the true impact of 1st order drainage areas from a contaminant perspective. The East and West Branch Brandywine Creek subbasins have the greatest total area of 1st order drainage area acreage as compared to the lower basin and main stem areas. This suggests preservation and protection efforts for first order streams will have the most impact on the E. and W. Branches and that pollution and land activities in these areas will have the greatest negative impact on the watershed. A more detailed analysis of land use within the first order stream and other stream corridors is discussed later in this section and section 3.
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Table 2-11 – Brandywine Creek Watershed First Order Stream Characteristics
Subbasin Name
Total
Stream
Miles
1st Order
Stream
Miles
% of
Total
Stream
Miles
Drainage
Area
(sq.mi)
1st order
miles/DA
Total
Acres
Acres in
1st Order
Drainage
Areas
% acres
first
order
Brandywine Creek at
Wilmington 6.8 2.1 30.9% 6.06 0.35 3877 399 10.3%
Upper W. Branch
Brandywine Creek 36.6 18.9 51.6% 30.24 0.63 19353 9751 50.4%
Upper E. Branch Brandywine
Creek 34.4 17.5 50.9% 25.66 0.68 16425 8570 52.2%
W. Branch Brandywine
Creek/Rock Run/Sucker Run 38.1 21 55.1% 27.08 0.78 17331 9760 56.3%
Buck Run 43.7 22.1 50.6% 26.89 0.82 17208 8631 50.2%
E. Branch
Brandywine/Beaver Creek 47.4 24.6 51.9% 26.06 0.94 16677 8106 48.6%
E. Branch Brandywine
Creek/Shamona Creek 28.2 17.4 61.7% 17.76 0.98 11368 7177 63.1%
Marsh Creek 34.6 20.1 58.1% 20.31 0.99 13000 7304 56.2%
Doe Run 39.4 23.7 60.2% 21.68 1.09 13872 8751 63.1%
West Valley Creek 37.2 24.4 65.6% 20.67 1.18 13227 8658 65.5%
Brandywine Creek/Pocopson
Creek 40.3 23.9 59.3% 19.74 1.21 12633 7457 59.0%
Brandywine Creek below
Chadds Ford 64.2 40.5 63.1% 30.36 1.33 19432 10891 56.0%
W. Branch Brandywine
Creek/Broad Run 66.4 39.3 59.2% 29.09 1.35 18620 10653 57.2%
E. Branch Brandywine
Creek/Taylor Run 27.4 17.5 63.9% 12.89 1.36 8247 5080 61.6%
Brandywine Creek above
Chadds Ford 22.3 14.7 65.9% 10.06 1.46 6437 3954 61.4%
Total 567 327.7 57.8% 324.55 1.01 207707 115142 55.4%
Source: Chester County Water Resource Authority, 2002
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Figure 2-14 – First Order Streams
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2.1.7. Watershed Growth, Population, and Land Use Impacts
The past, present, and future trends in population growth and land use in the watershed can be used to identify concerns and strategies related to current and future water quality issues. For example, less forests and more impervious cover can have water quality and quantity impacts. Though any general strategy is aimed at preventing both, the critical unknowns to most managers are how fast the land use will change and at what point a tipping point of irreversible negative impacts will be reached that could be avoided with long term planning and action.
There are very few estimates of long term population for the Brandywine Creek Watershed. However, there are recent estimates of the population in the watershed and predictions of future population growth. Table 2-12 provides these estimates and their relative population density in the watershed.
Table 2-12 – Past and Future Population Estimates For the Brandywine Creek Watershed
Source Year estimated average
population
density/sq. mile
estimated
population in
watershed
BVA SOW
Report 1998
1980 400 130,000
BVA SOW,
1997
1995 681 221,325
Brandywine
Watershed
Action Plan
1998 679 220,700
BVA SOW
Report 1998
2020 824 267,960
Brandywine
Watershed
Action Plan
2020 865 280,993
Previous studies have suggested population growth estimates of approximately 1,766 persons per year in the watershed (Brandywine Valley Association, 1998). These population growth estimates were used in past studies to predict future potential impervious cover in the watershed. It was estimated in 1998 that impervious cover would increase from 10.9% to 13.3% in 2020. This comes to an estimated 226 acres of impervious cover per year would be added to the watershed on average over that time.
Looking at these population and land use trends, it raises the question regarding how much
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forested land will be preserved or available to protect water quality over the coming 20 to 100 years. To answer this question, we need to understand a number of factors including the historical and current preservation rates of forests and the rate of forest cover loss. Historical rates of forest land cover suggest approximately 0.9 square miles of forest is lost per year in the watershed. For the purpose of this analysis a range from 0.5 to 1.875 square miles of forest lost per year was used. Historical rates of forest preservation are roughly 1.562 square miles per year. For the purpose of this analysis a range of 0.5 to 1.562 square miles per year was used.
If a range of forest preservation or forest losses and the starting point of 1998 are used for forested lands and preserved forested lands, a simplistic linear analysis estimates a range of future woodlands and impervious area scenarios that are possible in the next 10 to 60 years. Overall, this analysis suggests that the amount of forested land available and preserved forested land will roughly balance out between 2020 and 2070, depending upon the rates of forest land loss to development and rates of preservation. Depending on how preservation and development happens the forested land cover in the watershed could reach a balance point anywhere from 15% to 27% forested land cover (Table 2-13). As the forested land use drops towards the 15 to 20% range this will start to have negative impacts on aquatic life, water quality, flooding, base flow, and other hydrologic dependent aspects of the watershed. This also allows Wilmington to plan and estimate future water quality impacts and costs due to future land uses.
Table 2-13 – Past and Future Population Estimates For the Brandywine Creek Watershed
Scenario best case moderate
case
worst case
% forests/woodlands
remaining in watershed
21 to 27% 17-23 % 15 to 20%
years 2033 -
2070
2026 -
2046
2019 - 2028
According to equations for estimating treatment costs in the study by the Trust for Public Lands (Protecting the Source, 2004), the worst case reduction in forested land (15%) could have the potential for long term increased water treatment costs of over 30% for the City of Wilmington during the next 20 to 60 years. It is important to qualify that this is a preliminary estimate using national values and will need to be calibrated and validated with Wilmington specific costs at a later date. Regardless it does suggest some level of long term impact on treatment costs for Wilmington and a period (between 2030 and 2070) as to which actions to protect forested lands for the water supply will be ineffective. Overall, these findings also suggest that land preservation and loss of forested land will be a critical activity that will need to be conducted as soon as possible in order to protect Wilmington’s water supply.
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2.1.8. The Value of Watershed Preservation and Reforestation
A recent study by the United States Forest Service in the Northeast and Midwest found that the forests in 20 states help to protect more than 1,600 drinking water supplies that are the source of water for more than 52 million Americans (Barnes, 2009). The quality of the water depends, in part on the forest lands and their watersheds. The study mentions that the value of forests specifically to water quality and water supply is often overlooked by both the public and policymakers.
Potential for Significant Forest Losses
In the recent U.S. Forest Service study described above, the loss of forested lands is staggering in the Northeast and Midwest. Estimates suggest that forests in drinking water supply watersheds are being converted to other uses at an estimated rate of 350 acres per day with projected increases in the rate of loss to as much as 900 acres per day in 2030 with an overall loss of over 12 million acres of private forest land in these states by 2030. The common element to these losses is that over 82% of forested lands in the study were in private ownership which accelerates that loss of forested lands. Privately owned lands is a surrogate for the underlying factors related to zoning and other regulations of those private lands further accelerated by the residential real estate boom. Only 16% of the forested lands in the study were in State or Federal ownership. Specifically from the study, the State of Delaware and Pennsylvania were ranked using a number of factors. The study concluded that the State of Delaware was ranked above average in the Northeastern Area for having high-quality watersheds under development pressure. In addition, it identified that approximately 16.7 percent of private forestlands on high-quality watershed areas are subject to development pressure by 2030. In general, Delaware ranked in the top 11 percent of all the region’s watersheds because the watershed is at high risk for development and also provides high-quality drinking water to a large population. Over 85% of the forested lands in Delaware watersheds were identified as owned by private owners.
As mentioned previously in this plan, the forested land cover of the Brandywine Watershed is estimated at approximately 28% forested land cover in 2009 (data provided by GIS estimates by Brandywine Conservancy). Based on historical development rates and woodland loss information (Brandywine Conservancy report reference 2009), over the past 10 to 15 years there has been an average 1% per year loss in forested lands. This equals approximately 9.09 square miles of forested land lost per decade to development. Thus, 0.909 square miles per year of land (582 acres) should be reforested per year to address these losses in order to maintain the current estimated forest cover of roughly 28% (91.57 square miles) of forested land in the Brandywine Watershed.
Setting Priorities for Reforestation
According to a riparian zone analysis by the Brandywine Conservancy that looked at forest cover within 100’ of all mapped streams within the Brandywine watershed, there are roughly 13,000 acres of land potentially available for reforestation in riparian buffer areas
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in the Brandywine Creek Watershed (Brandywine Conservancy, unpublished data, 2009). Assuming 80% of these can actually be reforested, reforestation of all riparian buffer areas would only cover a portion of the total reforested lands needed for an ideal amount of forested lands like New York City or Boston uses for its water supply. Other high priority lands beyond riparian buffers such as headwaters drainage areas, steep slopes, significant connection to habitats and natural lands, etc. will need to be considered for reforestation as well as riparian areas. Other opportunities for reforestation include reforestation of a reasonable portion of currently protected open space of all kinds, including, for example state, county and municipal parks as well as private open space such as homeowner association lands and the eased properties of Brandywine Conservancy.
Though the costs to reforest the watershed may appear to be significant, increasing forest cover will help reduce many of the impairment issues with stormwater and other compliance needs would decrease. In terms of overall long term costs for the watershed this may be a viable strategy as an element of regulatory compliance. For example, stream restoration can cost upwards of $1 million per mile of streambank restored and with over 100 miles of impaired streams in the Brandywine Creek Watershed this could exceed $100 million to repair the stream without addressing the long term cause of the impairment. Managing an urban storm water utility for the entire watershed could have operating costs of up to $1 million per square mile per year depending upon the regulatory compliance needs and levels and extent of service. Thus, in terms of long term costs and returns, reforestation provides the best potential for long term return on investment, lowering stormwater compliance and water treatment costs compared to other approaches.
Perhaps the best way for stakeholders to achieve a significant increase in forested cover would be to merge efforts for carbon caps and carbon sequestration that need to be achieved by power companies and other industries with tree planting and reforestation and leverage regional, state, and national incentives and programs that will be developed around carbon reductions. For example, the costs of the trees and tree plantings could be subsidized by a company that needs the carbon credits. The cost of an easement for the reforested area could also be potentially added to those costs. Creating easements or land restrictions attached to property deeds for reforested areas would be a key to ensuring this approach. Another version of this program would be to create a “forest bank” similar to the approach used in wetland banking. An example of how this could occur is the following. A landowner that is interested in reforestation would contact a lead organization in the watershed. The organization would match the landowner looking for reforestation with funding from businesses in need of carbon credits. The organization in the middle of this transaction could serve as the banker or lender of the land for reforestation or for managing the reforestation funding depending on the most effective approach. The organization could also sell the carbon credits from other reforestation projects to interested businesses to recoup the costs of the reforestation and potentially cover funding for the next reforestation project.
Initial Steps to Address Future Deforestation and Reforestation
Because of its high value in protecting watershed health, preservation of existing forested
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lands is a primary priority. A secondary priority, however, is to establish more forested land cover than currently exists in the watershed through reforestation, particularly of high priority areas. It is recommended that the City of Wilmington reach out to other local governments in both states, key land management stakeholders, water suppliers, and environmental organizations in the watershed to discuss the concerning loss of forested lands and how to set in place a watershed wide initiative to stem the loss of forested lands and develop a sustainable framework for reforesting the watershed that could be linked to future carbon caps and credits. The management of the forested land in the watershed is the most critical long term activity that the region’s water suppliers will need to invest resources and efforts in order to protect the high quality water and reliable quantity of water that they currently enjoy from the Brandywine Creek or Hoopes Reservoir.
2.1.9. Analysis of Stream Impairments & Sources
A stream is considered impaired if it cannot meet the water quality and narrative standards that are used to define the fishable and swimmable goals of the Clean Water Act. In practice, the impairments to a stream are mostly based on macroinvertebrate or living organism assessments and water quality measurements. If the water quality fails to meet the water quality standards and criteria established by the designated use of the stream, it is considered impaired. In general, the Brandywine Creek main stem is listed by section 303d as impaired by nutrients, pathogens, and chlordane. The West Branch Brandywine Creek (including Sucker Run and other small tributaries) is listed as impaired by nutrients and siltation from agriculture as well as chlordane. The East Branch Brandywine Creek (including West Valley Creek, Taylor Run and some small tributaries) is listed for flow alteration and siltation. Roughly 20% of the stream miles in the Brandywine Creek are impaired as shown in Table 2-14. Table 2-15 and Figure 2-15 provides the breakdown of the impairment sources. Figure 2-16 provides a map of the impaired stream areas by source.
As shown, agriculture is the single largest source of impairment followed by urban/stormwater runoff, habitat and hydromodification (riparian buffer losses), unknown sources. These impairments are described in more detail in following sections.
Table 2-14 – Summary of Impaired Stream Miles in the Brandywine Creek Watershed
Watershed
Miles of
Stream
Impaired
Miles of
Stream
Attaining
Miles of
Unassessed
Steams
Total
Miles
Brandywine
Creek 102.94 427.5 5.41 535.85
Source PADEP, 2003
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Table 2-15 – Sources of Impairment in the Brandywine Creek Watershed
Protected Water Use (Chapter 93) Source of Impairment Miles Impaired Priority
Aquatic Life Agricultural 46.38 High
Fishing Fish Consumption Advisory* 5.85 High
Fishing Industrial Point Source *** 0 High
Aquatic Life Urban Runoff/Storm Sewers 30.82 High
Aquatic Life & Fishing Unknown Sources **** 35.79 High
Aquatic Life Habitat Modification 12.31 Low
Aquatic Life Hydromodification 6.66 Low
Aquatic Life Municipal Point Source 0 High
Aquatic Life Construction 0 Low
Aquatic Life Other 2.31 Low
Aquatic Life Natural Sources 0.68 Low
Miles Impaired
33%
4%0%
22%
25%
9%
5%
0%0% 2%
0%
Agricultural
Fish Consumption Advisory*
Industrial Point Source ***
Urban Runoff/Storm Sew ers
Unknow n Sources ****
Habitat Modif ication
Hydromodification
Municipal Point Source
Construction
Other
Natural Sources
Figure 2-15 – Breakdown of Miles of Stream Impairments by Percentage of Total Amount in the Brandywine Creek Watershed
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Figure 2-16 – Impaired Streams in the Brandywine Creek Watershed
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2.1.9.1. Urban Runoff Impairments
The industrial and urban development in the cities and boroughs of West Chester, Coatesville, Downingtown and Parkesburg have resulted in degradation of portions the Brandywine Creek watershed from municipal and industrial discharges and urban runoff and storm sewers. Streams through the urbanized areas also suffer from habitat alterations, flow variability, and siltation. The streams in the Brandywine Creek with the most impairment are those in the industrial/urban areas of Dowingtown (East Branch Brandywine Creek and Beaver Creek), Coatesville (Valley Creek, Sucker Run, and West Branch Brandywine Creek), Parkesburg (Buck Run), and West Chester (Taylor Run). These impaired areas also have some of the highest percentage of impervious surface in the watershed. The highest percentages of impervious surface are in West Valley Creek watershed (20%), which flows into Downingtown and the lower East Branch Brandywine Creek near West Chester (15%).
2.1.9.2. Agricultural Impairments
Streams in the Honey Brook area (upper East Branch, West Branch and Honey Brook Creek) are impaired due to agricultural runoff. Agriculture impairments impact the East and West Branches of Brandywine Creek, Plum Run, Radley Run, Sucker Run, Buck Run, Broad Run, and Indian Run. Crop and animal production can adversely impact aquatic life. Erosion of topsoil and runoff of applied manure or chemical fertilizers contribute to stream sedimentation and nutrient loading. Barnyard runoff of manure and proximity of livestock to the stream can also contribute to nutrient loading and sedimentation (bank destabilization) respectively. Agricultural best management practices are voluntary and little regulation exists for reducing pollutant loads from agricultural areas.
2.1.9.3. Municipal Point Source Impairments
Municipal point source discharges also cause organic enrichment and low dissolved oxygen in Beaver Creek, Buck Run, and Broad Run.
2.1.9.4. Linking Impairment Reduction with Water Supply Protection
An impaired stream can be subject regulation in order to return it to an unimpaired status. Sometimes, but not always, the sources of impairment to aquatic life may also have impacts on water treatment. Since the regulatory authority to address water quality impacts for water supply is not organized in a way that makes it effective, the most powerful and effective regulatory approach is to coordinate regulation of water supply issues with impairment regulation. This can result in promulgation of total maximum daily loads to reduce permitted discharges from point sources such as wastewater plants and stormwater outfalls. TMDLs have been promulgated for nutrients, TSS, and bacteria for the Brandywine Creek. Thus, it is critical for Wilmington to monitor the TMDL implementation process to
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ensure it addresses their upstream sources of concern appropriately.
2.2. Surface Water Intakes
2.2.1. Surface Water Withdrawals and Community Water Systems
The Brandywine Creek watershed has numerous surface water withdrawals for public water supply, commercial and industrial uses. A total of 37 surface water withdrawals are inventoried in the watershed, and in 1998, it was estimated that there were over 15 billion gallons withdrawn from the watershed. A total of 31 million gallons of water per day are withdrawn by surface water supplies for drinking water, irrigation, and commercial/industrial needs in the watershed. This is roughly 17% of the average daily flow in the Brandywine Creek.
As described earlier, certain withdrawals are either partially or fully offset by waters stored in Marsh Creek Reservoir or Chambers Lake. Table 2-17 and Figures 2-17 & 2-18 provide a summary of the major withdrawals from the Brandywine Creek and their types.
Table 2-16 – Surface Water Withdrawals by Type in the Brandywine Watershed
Withdrawal Type
Maximum Permitted Withdrawal
(MGD)
Total Average Withdrawal
(MGD)
Public Water Supply 57.7 27.2
Commercial / Industrial 8 3.5
Irrigation 3.8 0.3
TOTAL 69.5 31
Several existing community water supply systems in the watershed rely on ground water sources. In addition, several surface water intakes and treatment plant facilities for public supplies exist in the Brandywine Creek watershed. Such sources may offer opportunities for future supplies both within and adjacent to their corresponding subbasins. Table 2-16 provides a specific breakdown of the detailed withdrawal information for major suppliers. Table 2-18 provides a list of the remaining 63 small community systems in the Brandywine Creek Watershed.
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Specific information for the major water supply intakes are as follows:
Pennsylvania American Water Company Rock Run Reservoir – The current allocation is 3 MGD. The current average daily withdrawal volume is approximately 2.5 MGD.
Pennsylvania American Water Company West Branch Brandywine - The current allocation is 4 MGD. The current use of this intake is only on an as needed basis, generally during prolonged drought events, to supplement the Rock Run Reservoir. During recent drought events, maximum daily withdrawal volume was approximately 2 MGD.
Figure 2-17 – Comparison of Maximum Major Surface Water Withdrawal from the Brandywine Creek
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Figure 2-18 – Comparison of Average Major Surface Water Withdrawal from the Brandywine Creek
Downingtown Municipal Water Authority (DMWA) East Branch Brandywine Creek/Downingtown – The current maximum allocation is 2.5 MGD. The DMWA has additional water supply storage allocation available in Marsh Creek Reservoir to support a total allocation of 3.8 MGD. The DMWA’s current average daily withdrawal volume is approximately 1.1 MGD.
Aqua Pennsylvania Water Company East Branch Brandywine Creek/Ingram’s Mill - The current allocation is 6.0 MGD, with a 1-day maximum of 8.5 MGD. The current average daily withdrawal volume at this intake is approximately 2.8 MGD.
These existing surface water intakes potentially represent sources of additional water for other subbasins depending on the proximity of connecting infrastructure to the area of need and impact to subbasin water balances. Several inter-basin and inter-watershed transfers of water already exist in Chester County’s watersheds. Examples of the distribution of water from surface water sources include:
The Pennsylvania American Water Company’s Coatesville regional distribution system serves water from 3 sources of surface waters including the Rock Run and West Branch
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Brandywine intakes listed above, and an intake on upper West Branch Octoraro Creek.
The Downingtown Municipal Water Authority’s intake on East Branch Brandywine provides water for the immediate Downingtown region.
The Ingram’s Mill intake (Aqua-PA) on East Branch Brandywine Creek serves water to much of the greater West Chester region.
The City of Wilmington’s source of water for its water distribution system is in the lower Brandywine Creek watershed. The City also operates Hoopes Reservoir for use when extended dry weather events necessitate additional water to meet demands.
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Table 2-17 – Detailed Listing of Major Surface Water Withdrawals From the Brandywine Creek Watershed for 1998
Flow (Mgal/d)
Subbasin withdrawals
Name Type capacity or flow
limit
1994-1998
average
West Branch City of Coatesville Authority - W. Branch Brandywine Creek
DW 1 0.354
West Branch City of Coatesville Authority - Rock Run
DW 3 2.68
West Branch Lukens Steel IND 4.76 1.35
West Branch Sealed Air Corporation IND 0.278 0.034
West Branch Embreeville Center DW 0.2 0.149
East Branch Downingtown Municipal Authority DW 2.5 1.02
East Branch Sonoco Products IND 1.32 1.6
East Branch Milestone Materials IND 0.62 0.42
East Branch Whitford Country Club IRR 0.643 0.026
East Branch Philadelphia Suburban Water- Ingrams Mill
DW 6 2.8
East Branch Brandywine Paperboard IND 0.024 0.019
Main stem Radley Run Country Club IRR 0.1 0.02
Main stem Brandywine Country Club IRR 0.51 0.022
Main stem Wilmington Country Club IRR 1.8 0.165
Main stem Dupont Country Club IRR 0.72 0.019
Main stem Wilmington Finishing IND 1 0.046
Main stem City of Wilmington DW 48 25
Source: Keorkle and Senior, 2002
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Table 2-18 – List of Small Community Water Systems in the Brandywine Creek Watershed
Number System Name Number System Name
1 Appleville Mobile Home Park 33 Londonderry Court
2 Avonwhell Estate Mobile Home Park 34 Longwoods Gardens
3 Brandywine Terrace Mobile Home Park 35 Malvern Courts Inc.
4 Caln Mobile Home Park 36 Maplewood Mobile Home Park
5 Camp Hill Special School 37 Martin's Mobile Home Village
6 Camphill Village USA Inc. 38 Movern Mushroom Farms
7 CFS - School at Church Farm 39 Mount Idy Mobile Home Park
8 Chatham Acres Nursing Home 40 Nottingham Manor Mobile Home Court
9 Chatwood Water Company 41 Oxford Village Mobile Home Park
10 Coatesville Veterans Administration Hospital 42 Perry Phillips Mobile Homes
11 Cochranville Mobile Home Park 43 Phoenix Mobile Homes
12 Coventry Garden Apartments 44 Phoenixville Mobile Homes Inc.
13 Coventry Manor Nursing Home 45 Philadelphia Suburban Water Co. -
Culbertson Run
14 Coventry Terrace 46 Philadelphia Suburban Water Co. -
Brandywine Hospital
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15 Devereux Foundation 47 Ridgeview Mobile Homes
16 East Fallowfield Utilities, Inc. 48 Riveredge
17 Echo Valley 49 S.E. PA Veterans Center
18 Gregory Courts Inc. 50 Shady Grove Mobile Home Park
19 Heatherwood Retirement 51 Shady Side Mobile Home Park
20 Hideaway Mobile Home Park 52 Springton Court Mobile Homes
21 Highland Court 53 St. Mary's of Providence
22 Icedale Mobile Home Courts 54 St. Stephens Green
23 Imperial Mobile Home Park 55 Stone Barn
24 Independence Park 56 Stoney Run Mobile Home Park
25 Indian Run Village 57 Taylor's Mobile Home Park
26 Kendal Crosslands/Consiston 58 Tel Hai Rest Home
27 Keystone Court 59 Valley Springs Water Co.
28 Lake Road Mobile Home Park 60 Valley View Mobile Home Park
29 Lazy Acres Mobile Home Park 61 Warwick Mobile Home Park
30 Lincoln Crest Mobile Home Park 62 Wetherhill Estates
31 Loags Corner Mobile Home Park 63 Willowdale Water Company
32 London Grove Mobile Home Park
Source: Chester County Water Resources Authority, 2001
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2.2.2. Groundwater Withdrawals
Groundwater withdrawals are important sources of drinking water for small communities and can have localized or global impacts on the baseflow of a watershed depending on a number of factors. Table 2-19 provides a summary of the results from a groundwater withdrawal capacity and sustainability analysis in the Chester County Compendium (Chester County Water Resources Authority, 2001) to determine which subbasins in the watershed may see negative impacts. When the percent of net withdrawals is less than 50% of the subbasin’s target, the ground water resources are considered non-stressed. Net withdrawals greater than 50% are considered potentially stressed. Net withdrawals near or exceeding 100% are considered stressed. Using these criteria, the only area determined to have potential negative impacts or unsustainable groundwater capacity was the West Valley Creek subbasin. All other subbasins in the watershed were determined to have appropriate capacity for growth up to and possibly beyond 2020.
In Table 2-20 the relative total annual withdrawals of groundwater and surface water are summarized along with future needs for water and wastewater by subbasin. The table shows that for the watershed, an estimated 4.05 billion gallons per year or 21% of the water withdrawn is from the ground water supplies. There is an estimated 1.6 billion gallons per year recharged back to the aquifers, for a net ground water withdrawal of 2.5 billion gallons per year for the Brandywine Creek watershed in 1998. The methodology and data used to develop these estimates were presented in the Chester County Compendium (Chester County Water Resources Authority, 2001).
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Table 2-19 – Summary of 1998 Net Ground Water Withdrawals by Subbasin (in MGY)
Subbasin Name 1 in 25 year
Average Annual
Base Flow
Groundwater
Withdrawal Target as %
of 1 in 25 Yr Baseflow
Volume
Withdrawn
Volume
Recharged
Net
Withdrawal
Net Withdrawal as %
of Withdrawal Target
Brandywine Creek Above
Chadds Ford
1098 50% 65 133 -68 -12%
Brandywine Creek at
Wilmington
661 100% 17 14 3 0%
Brandywine Creek below
Chadds Ford
3313 100% 112 31 81 2%
Brandywine Creek/Pocopson
Creek
2154 100% 283 173 110 5%
Buck Run 2925 100% 121 82 39 1%
Doe Run 2358 100% 46 39 7 0%
East Branch Brandywine
Creek/Shamona Creek
1938 50% 216 104 112 12%
East Branch Brandywine
Creek/Taylor Run
1407 50% 174 67 107 15%
East Branch Brandywine /
Beaver Creek
2825 50% 627 172 455 32%
Marsh Creek 2217 50% 274 149 125 11%
Upper East Branch
Brandywine Creek
2800 50% 166 104 62 4%
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Upper West Branch
Brandywine Creek
3300 50% 302 120 182 11%
West Branch Brandywine
Creek/Broad Run
3175 50% 310 230 80 5%
West Branch Brandywine
Creek/Sucker Run
2945 50% 290 106 184 12%
West Valley Creek 2233 50% 1046 45 1001 90%
Total 4049 1568 2481
Source: Chester County Water Resource Authority, 2001
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Table 2-20 – Estimated Average Annual Water Withdrawals and Future Needs by Subbasin (in MGY)
1998 Withdrawals 2020 Projected Needs
Subbasin Name Groundwater
Withdrawals
Surface
Water
Withdrawals
Total Water
Withdrawals
Total
Water
Used
Additional
Water
Demand
Additional
Wastewater
Capacity
Needs
Brandywine Creek Above Chadds Ford 65 0 65 159 74 67
Brandywine Creek at Wilmington 17 9905 9922 1726 185 167
Brandywine Creek below Chadds Ford 112 74 186 613 119 107
Brandywine Creek/Pocopson Creek 283 22 305 601 166 149
Buck Run 121 0 121 266 43 39
Doe Run 46 0 46 46 11 10
East Branch Brandywine Creek/Shamona Creek 216 379 595 439 157 142
East Branch Brandywine Creek/Taylor Run 174 1480 1654 628 96 87
East Branch Brandywine / Beaver Creek 627 648 1275 929 237 213
Marsh Creek 274 0 274 188 145 131
Upper East Branch Brandywine Creek 166 2 168 143 54 48
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Upper West Branch Brandywine Creek 302 0 302 212 71 64
West Branch Brandywine Creek/Broad Run 310 0 310 255 100 90
West Branch Brandywine Creek/Sucker Run 290 1777 2067 988 261 235
West Valley Creek 1046 1128 2174 966 303 273
Total 4049 15415 19464 8159 2023 1820
Source: Chester County Water Resource Authority, 2001
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2.2.3. Time of Travel Delineations
The location of a potential source or existing source of contamination in relation to the downstream water intake is critical to determining its planning priority and emergency response preparation. For example, during a low probability accident, a large storage tank or bridge crossing located just upstream of an intake would potentially represent an opportunity for a significant negative immediate impact on the water supply intake downstream. Another situation might represent an upstream discharger that is always in compliance, but may have an unforeseen operational problem beyond their control. In these situations, the water utility will need to know how long a potential discharge from these facilities could reach the intake at the earliest, the most likely time to reach the intake, and how long it will take for the pollutant plume to pass. This information is critical for the water supplier to determine how long to pull from the creek, when to shut down the intake, and how long it will need to use an alternative source. Other information such as the type of contaminant will also determine what water monitoring methods and potential treatment changes are employed during the event. Other than accidents, routine events such as localized thunderstorms and discharges from facilities that are out of compliance or discharging different contaminants sporadically (taste and odor compounds) also represent periods when this information is useful.
The City of Wilmington has the capability to switch from the Brandywine Creek as its main water source to the Hoopes Reservoir during periods of undesirable water quality. In order to maximize this capability, the City of Wilmington contracted the USGS to develop a turbidity early warning system that would provide advance warning of approaching turbidity spikes to the City’s intakes so it could switch to the Hoopes supply prior to the arrive of the turbidity spike. Typically during dry weather periods the turbidity is only 1-2 NTU, but during wet weather events it can exceed 200 NTU. These higher turbidities have been associated with elevated levels of other contaminants that are described in depth in section 2.3.
The first step in this process was developing potential relationships between the flow at Chadds Ford and the peak turbidity at Wilmington’s intake. It was determined from analysis of existing data that at 2,000 cfs the turbidity at the Wilmington intake exceeded 20 NTU which was greater than desired for use by Wilmington. Another analysis of the timing of the turbidity peaks was conducted by USGS. It determined that when the flow at Chadds Ford reached 2,000 cfs that the turbidity spike would reach Wilmington’s intakes in less than 8 hours. This was tested in the summer of 2006 and validated against existing data by USGS. Attempts were made later in 2006 by USGS to extend the warning system to upstream stations at the bottom of the East and West Branches of the Brandywine Creek, but similar relationships like the one with Chadds Ford could not be developed.
An analysis was conducted to estimate the ranges of time for something released into the Brandywine Creek or its tributaries to reach the City of Wilmington Intake. In Figure 2-19, a graph of the range of potential travel times is provided to estimate the earliest arrival of a contaminant in a given situation. The left side of the graph represents the distance of the release from the intake and increases as it progresses to the right. The right axis on the graph represents the estimated time in hours for the release to reach the intake. It is important to note that these estimates represent a conservative estimate of the leading
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edge of a plume to reach the intake under various conditions. A range of average flows are shown on the graph ranging from 0.5 ft/s to 5 ft/s. Flow velocities vary significantly across the stream cross section and along the length of a stream. Therefore, these are meant to represent average cross sectional velocities over the length of the release distance. It is important to note that this graph does not estimate the time for maximum concentration to arrive or for the tail of the plume to pass the intake. Also, the type of contaminant released can have a significant effect on transport. For example, some oils may tend to stay near the surface and be affected by wind dispersion or trapped behind rock weirs and dams while other contaminants may dissolve completely and not be affected by these phenomenons. Site specific bends and impoundment areas along a stream, especially mill dams may significantly delay a contaminant plumes arrival and can prolong its presence in the stream.
The effect of stream velocity on distance traveled is shown in Figure 2-20. As shown, the farthest stream distance to travel in the Brandywine Creek is roughly 50 miles. Depending upon the velocity of the stream it can take anywhere from 15 hours to 6 days to go that distance. A stream velocity of 0.5 ft/s represents an average slow flow in the creek. This flow typically is near settling velocity for larger particles. A stream velocity of 2 ft/s represents the speed at which particles reach a “scouring” velocity where particles on the stream bottom may become suspended. This speed represents a speed of particle transport with little settling attenuation. A velocity of 5 ft/s is the peak bank full velocity estimated by the USGS for various locations in the Brandywine Creek watershed and represents the fastest flow velocity that can be observed. This represents the fastest a contaminant could reach the Wilmington intake.
As shown in Figure 2-19, under dry weather conditions, spills from the farthest reaches of the watershed will make it to the intake in less than 6 days and probably less than 2 days under normal conditions without impoundments. Under dry weather conditions, spills from the Route 30 corridor such as Coatesville, Malvern, and Downingtown will reach the intake in roughly 1 to 3 days. Under dry weather conditions, spills on the main stem can reach the intake in less than a day in most cases. Under bank full flow conditions, all spills from all locations will reach the Wilmington intake in 5 to 15 hours unless there is an impoundment such as in one of the large reservoirs in the basin.
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0
10
20
30
40
50
60
To
p o
f
Ma
inste
m
(E&
W jo
in)
We
st
Ch
este
r
Do
wn
ing
tow
n
Co
ate
sville
Ma
lve
rn
To
p o
f E
.
Bra
nch
To
p o
f W
.
Bra
nch
Location
Dis
tan
ce (
str
eam
mil
es)
0
20
40
60
80
100
120
140
160
Ho
urs
to
in
take (
ho
urs
)
distance (stream miles)
hours @ 0.5 ft/s
hours @ 5 ft/s
hours @ 2 ft/s
Figure 2-19 – Estimated Time of Travel and Distance from Various Locations in the Brandywine Creek Watershed to Wilmington’s BFP Intake
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Figure 2-20 – Distance Traveled (miles) As a Function of Stream Velocity
0
20
40
60
80
100
120
140
160
0 10 20 30 40 50
Distance (miles)
Ho
urs
0.5 ft/s
1 ft/s
2 ft/s
5 ft/s
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2.3. Identification of Universal Water Quality Issues
Summary of Water Quality Data Findings
When raw water turbidity exceeds 10 NTU the raw water quality has higher levels of disinfection by product precursors, pathogens, and ammonia.
The greatest chloride, sodium, and conductivity concentrations are associated with periods of road salt application. Long term increasing trends of these parameters were observed. When the conductivity at Wilmington is approximately 500 to 600 (units), chloride levels may reach 100 to 150 mg/L.
Preliminary data suggests that a UV254 reading of between 0.15 and 0.2 is a threshold where increased TOC and precursors are present and additional treatment or alternative sources such as Hoopes may be desired.
The detection rates of Cryptosporidium and Giardia suggest there is greater than normal presence of protozoa at the Brandywine and Porter intakes.
Pharmaceuticals have been detected in the Brandywine Creek including pharmaceuticals from both human and livestock sources.
Nutrient spikes during spring wet weather events suggest agriculture and suburban runoff are considered the greatest sources of nutrients with agriculture considered the greatest priority
Approximately one third to one half of the algae observed was filter clogging or nuisance algae. This suggests a potential for future taste & odor issues.
Chloride and conductivity appear to have the most pronounced and continuous increasing trends from the early 1970s to current periods in the Lower Brandywine. There is no indication that this trend is “leveling off” or diminishing.
Alkalinity and hardness appear to have increasing trends that mirror that of chloride and conductivity, but appear to be related to groundwater and base flow changes. If baseflow is reduced in the watershed and surface runoff is increased over time, the proportion of observations in the higher TOC removal categories will increase.
Total phosphorus appears to be decreasing while total orthophosphate concentrations remain relatively unchanged.
Nitrate concentrations historically increased since the 1970s, but appear to be leveling off in recent years while ammonia concentrations have decreased historically.
Dissolved oxygen concentrations appear to have some limited decreasing trend since the mid 1980s.
There were no discernible historical trends observed for total organic carbon, bacteria/pathogens, total iron and manganese, temperature, and pH. Trends may be occurring, but analytical method variability, analytical detection limits, analytical method changes, and frequency/seasonality of monitoring may not have been able to detect them.
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Raw water quality can have significant impacts on water treatment and finished water quality. Some contaminants are easily removed by the water treatment process. Other contaminants can actually have a negative impact on the water treatment process performance, require additional treatment, or affect distribution system chemistry such as corrosion control. Table 2-21 summarizes the general contaminant groups and their importance to water treatment.
Table 2-21 – Summary of Generalized Water Treatment & Distribution Impacts from Raw Water Quality
Contaminant Group
Water Treatment
Removal
Water Treatment
Impact
Distribution System Impact
Finished Water Impact
Disinfection by Product Pre-
cursors
Medium Higher Chlorine demand & more chemicals added
biofilm Higher Disinfection by-products
Pathogens (Cryptosporidium)
Low N/A N/A Increased Risk of Gastrointestinal
illness
Turbidity High More treatment chemicals added
N/A Increased Risk of Gastrointestinal
illness
Nutrients (ammonia, nitrate,
etc.)
Low Higher Chlorine demand
biofilm & corrosion
control
Plumbing corrosion impacts
Algae Medium Filtration clogging, more
frequent backwashing
N/A taste & odor complaints
Metals High Higher chlorine demand
Corrosion control
Plumbing corrosion impacts
Trace Organics Low N/A biofilm N/A
Chloride & Sodium Low Limits chemical salt addition for
coagulation
N/A taste & plumbing corrosion
Hardness & Alkalinity
Medium Affects coagulation chemistry & TOC control
Corrosion control
taste, scaling, plumbing
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2.3.1. Summary of Wilmington Intake Water Quality Data (1996-2007)
Intake data for the City of Wilmington raw water intake was analyzed for the period from 1996 to 2007. Analysis included basic statistics, seasonal variation, and potential correlation with other parameters. The maximum, minimum, and average concentrations are shown in Table 2-22 and Figure 2-21. As shown the most variable data is pathogens which by the very nature of the analytical method can create a 100 fold variation. Then metals and nutrients are the next in terms of overall variability. Inorganics exhibit natural variability given it’s a surface water body with a large drainage area. Finally, disinfection by product pre-cursors exhibit the least variability of all the contaminants, but are important because though low variability is observed, even small variability in pre-cursors can have a great impact on DBP formation during drinking water treatment.
0.001
0.01
0.1
1
10
100
1000
10000
E_ C
oli
Ente
rococci
Tota
l C
olif
orm
Tota
l O
rganic
Carb
on
Ultra
-Vio
let
Absorb
ance @
254nm
Alk
Calc
ium
Chlo
ride
Conductivity
Hard
ness
pH
Sulfate
Tem
pera
ture
Thre
shold
Odor
Num
ber
Turb
idity
Tota
l Ir
on
Tota
l M
anaganese
Zin
c
Am
monia
Nitra
te
Nitrite
Ort
hophosphate
Parameter
Co
ncen
trati
on
s
max
min
median
Biological MetalsInorganicsDBP Nutrients
Figure 2-21 – Concentration Ranges for Various Parameters in Wilmington’s Raw Water
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Table 2-22 - Summary of Wilmington Raw Water (Brandywine Creek) Water Quality 1996 - 2007
Group Parameter max min average 95% confidence
limit (upper)
95% confidence
limit (lower)
median standard deviation
90th percentile
count (N)
Biological E. Coli 2419.2 1 182.1 224.3 140.0 45.3 432.7 291.9 405
Enterococci 1226.2 1 96.9 173.4 20.5 19.7 230.8 256.2 35
Total Coliform 9805 9 778.8 861.8 695.7 200.5 953.1 2419.2 506
DBP Total Organic Carbon 7.69 1.2 2.5 2.6 2.3 2.1 1.0 3.8 336
UV 254 Absorbance 0.36 0.031 0.079 0.083 0.076 0.065 0.0455 0.135 592
Inorganic Alkalinity 94 15 52.6 53.0 52.2 52.0 9.2 64.0 2447
Calcium 26 2 20.5 21.7 19.3 22.0 6.1 25.0 95
Chloride 313 10 35.1 35.6 34.6 33.0 12.7 44.0 2449
Conductivity 1720 90 269.3 271.7 267.0 270.0 59.6 320.0 2500
Hardness 141 50 93.1 94.2 92.0 94.0 13.9 110.0 652
pH 8.6 6.2 7.4 7.4 7.3 7.4 0.2 7.7 2582
Sulfate 16.87 8.04 13.9 15.7 12.1 15.2 3.0 16.3 11
Temperature 30 2 15.1 15.4 14.8 14.0 6.9 25.0 2080
Threshold Odor Number
4 1 3.97 4 3.91 4 0.29 4 106
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Group Parameter max min average 95% confidence
limit (upper)
95% confidence
limit (lower)
median standard deviation
90th percentile
count (N)
Turbidity 260 0.46 6.4 7.0 5.8 2.4 15.7 11.1 2587
Metals Total Iron 1.401 0.004 0.2 0.2 0.2 0.1 0.2 0.3 396
Total Manganese 0.221 0.005 0.0 0.1 0.0 0.0 0.0 0.1 119
Zinc 0.662 0.0003 0.1 0.1 0.0 0.0 0.1 0.1 438
Nutrients Ammonia 0.9 0.005 0.1 0.1 0.1 0.1 0.1 0.3 129
Nitrate 3.6 0.4 2.1 2.2 2.0 2.1 0.6 2.9 143
Nitrite 0.36 0.001 0.0 0.0 0.0 0.0 0.0 0.0 127
Orthophosphate 2.2 0.01 0.3 0.3 0.3 0.2 0.1 0.4 623
Note: yellow highlights represent concentrations that have potential to create operational challenges:
Red represents concentrations that would exceed an MCL for finished water and therefore require removal by water treatment
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2.3.2. General Potential Seasonal and Source Impacts
Based on the analysis of the seasonal impacts of the water quality data provided in later sections, the most important findings are provided in Table 2-23. Table 2-24 provides the detailed findings for all the contaminants analyzed. As shown in Table 2-23, wastewater, urban and suburban runoff, and agriculture are the three potentially greatest significant and driving sources that impact water quality at the Wilmington intake. In addition, the impacts of these activities on the hydrologic cycle and baseflow as well as peak storm flows are reflected in the observed intake data. Overall, the data suggests that wastewater discharges have the greatest dry weather impact on overall priority contaminants for water treatment in the Brandywine Creek. Urban/Suburban Stormwater Runoff and Agricultural Runoff (seasonal) tend to have the greatest impact on wet weather water quality. Some studies have suggested that runoff related contaminants such as bacteria can also have dry weather affects as they are released from sediment (Cinotto, 2006). Overall, wet weather sources are considered the most significant source of all contaminants except for pathogens and emerging contaminants such as personal care products and pharmaceutical compounds which require more study.
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Table 2-23 - Summary of Priority Contaminants by Potential Impact
Potential General Priority Contaminant Sources
Priority Contaminant or Contaminant Group
Dry Weather Wet Weather
Flow* Wastewater discharges & groundwater
withdrawals
Urban/Suburban Stormwater Runoff
Pathogens Wastewater & sediment
regrowth/release
Agriculture, wildlife, sediment resuspension, suburban runoff
Disinfection By Products Wastewater Trees, agriculture, urban/suburban stormwater runoff
Algae Wastewater Agriculture
Chlorides Wastewater Road Salt Runoff
Turbidity Construction & accidents
Urban/Suburban Stormwater Runoff & Agriculture
Alkalinity Groundwater Urban/Suburban Stormwater Runoff
Nutrients Wastewater Agriculture & Urban/Suburban Stormwater Runoff
Metals Groundwater Urban/Suburban Stormwater & Road Runoff
Trace Organics (includes pharmaceuticals)
Wastewater Agriculture & Urban/Suburban Stormwater Runoff
* flow is not a regulated contaminant, but has a major impact on the concentrations and loads of all contaminants and therefore hydrologic impacts must be considered in a source prioritization.
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Table 2-24 – Summary of Seasonal Impacts and Potential Source Information
Group Parameter Dry Weather Potential Sources
Wet Weather Potential
Sources
Peak value of
record
Season(s) Peak
Values Occur
Lowest value of
record
Season(s)
Lowest Values
Occur
Preliminary Potential
Dominant Source - dry
weather
Preliminary Potential Dominant
Source - wet weather
E. Coli
wastewater, septic systems,
defective laterals, animal sources
wildlife, livestock,
urban/suburban stormwater N/A Winter/Spring N/A Summer wastewater
agriculture & urban/ suburban
stormwater
Enterococci
wastewater, septic systems,
defective laterals, animal sources
wildlife, livestock,
urban/suburban stormwater N/A Winter/Spring N/A Summer wastewater
agriculture & urban/ suburban
stormwater
Total Coliform
wastewater, septic systems,
defective laterals, animal sources
soils, wildlife, livestock,
urban/suburban stormwater N/A Summer N/A Spring unknown soil related sources
Total Organic Carbon wastewater
spring due to near bank sources
of plant organics, fall due to
canopy material
May/June and Sept
to Dec
late winter to early
spring unknown unknown
UV 254 Absorbance wastewater
spring due to near bank sources
of plant organics, fall due to
canopy material
May/June and Sept
to Dec
late winter to early
spring unknown unknown
Alkalinity groundwater urban/suburban stormwater 2/00, 9/02, 10/99 Fall 1/99, 4/00 winter groundwater urban/suburban stormwater
Calcium groundwater urban/suburban stormwater August 2003 April, July, August groundwater urban/suburban stormwater
Chloride
wastewater & industrial
discharges road salting January 1999
early winter to
early spring late spring (May) unknown road salting
Conductivity
wastewater & industrial
discharges urban/suburban stormwater January 1999
early winter to
early spring late spring (May) unknown road salting
Hardness groundwater urban/suburban stormwater August 2003 April, July, August groundwater urban/suburban stormwater
pH algae urban/suburban stormwater N/A April, July, August wastewater agriculture
Sulfate groundwater urban/suburban stormwater groundwater urban/suburban stormwater
Temperature
wastewater & industrial
discharges urban/suburban stormwater 8/06, 7/99 Summer 3/07, 12/00, 1/96 winter wastewater urban/suburban stormwater
Threshold Odor Number algae
Turbidity construction sites & accidents
Stream erosion from
urban/suburban stormwater,
agriculture unknown
agriculture & urban/ suburban
stormwater
Total Iron groundwater urban/suburban stormwater 1999 drought
spring, summer,
fall winter groundwater urban/suburban stormwater
Total Managanese groundwater urban/suburban stormwater 1999 drought
late spring/early
summer winter groundwater urban/suburban stormwater
Zinc groundwater urban/suburban stormwater 1999 drought winter & spring fall groundwater urban/suburban stormwater
Ammonia
agriculture, wastewater, septic
systems
agriculture, urban/suburban
stormwater winter/spring
summer 2002
drought summer wastewater agriculture
Nitrate
agriculture, wastewater, septic
systems
agriculture, urban/suburban
stormwater winter
summer 2002
drought summer wastewater agriculture
Nitrite
agriculture, wastewater, septic
systems
agriculture, urban/suburban
stormwater winter
summer 2002
drought summer wastewater agriculture
Orthophosphate
agriculture, wastewater, septic
systems
agriculture, urban/suburban
stormwater spring
summer 2002
drought summer wastewater agriculture
Algae
agriculture, wastewater, septic
systems urban/suburban stormwater N/A N/A N/A N/A wastewater agriculture
Cryptosporidium
agriculture, wastewater, septic
systems, animals
wildlife, livestock,
urban/suburban stormwater N/A N/A N/A N/A wastewater & sewage agriculture & wildlife
Giardia
agriculture, wastewater, septic
systems, animals
wildlife, livestock,
urban/suburban stormwater N/A N/A N/A N/A wastewater & sewage agriculture & wildlife
EDCs
wastewater & industrial
discharges
agriculture, urban/suburban
stormwater N/A N/A N/A N/A wastewater agriculture & wildlife
Nutrients
Biological
DBP
Inorganic
Metals
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2.3.3. Inorganics
Table 2-25 and Figure 2-22 provide a summary of the ranges of inorganics concentrations in the raw water at the Wilmington intake from 1996 to 2007. Conductivity was the most variable parameter followed by chloride, turbidity, and hardness. pH stayed within a limited range of 6.2 to 8.4 with an average of 7.4.
Table 2-25 - Inorganics Concentrations at the Wilmington Intake: 1996 To 2007
Parameter Alkalinity Calcium Chloride Conductivity Hardness pH Temperature Turbidity
max 94 26 313 1720 141 8.6 30 260
min 15 2 10 90 50 6.2 2 0.46
average 52.6 20.5 35.1 269.3 93.1 7.4 15.1 6.4
median 52 22 33 270 94 7.36 14 2.4
std. dev. 9.21 6.15 12.66 59.56 13.87 0.24 6.94 15.73
90%tile 64 25 44 320 110 7.7 25 11.1
N 2447 95 2449 2500 652 2582 2080 2587
0.1
1
10
100
1000
10000
Alk
alin
ity
Calc
ium
Ch
lori
de
Co
nd
ucti
vit
y
Hard
ness
pH
Tem
pera
ture
Tu
rbid
ity
Parameter
Co
ncen
trati
on
s
max
min
avg
Figure 2-24 - Summary of Inorganics Concentrations at the Wilmington Intake from 1996 To 2007
As shown in Figure 2-25, the greatest conductivity occurred during January 1999 and
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January 2002. The greatest chloride occurred during January 1999. The greatest turbidities were observed during November 2002, April 2004, and June 2006 (after a tropical depression). The lowest chloride and conductivity values were observed on 9/17/99 after Hurricane Floyd. The warmest water temperatures occurred during August 2006 and July 1999. The coldest water temperatures occurred during March 2007, December 2000, and January 1996. The greatest hardness was observed on August 2003. The greatest alkalinity was in February 2000, September 2002, and October 1999. The lowest alkalinity concentrations were observed from January 1999 to April 2000.
0.1
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1000
10000
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6/0
7
12/2
4/0
7
Date
Ino
rgan
ics
Alk Calcium Chloride
Conductivity Hardness pH
Temperature Turbidity
Figure 2-25 - Comparison of Daily Measurements of Inorganics at the Wilmington Intake 1996 - 2007
2.3.4. Chloride & Conductivity Trends From Road Salts
Based upon preliminary review of Wilmington’s intake data from 1996 to 2007, it is apparent that the highest conductivity and chloride concentrations appear during the months of December, January, February, and March (see Figures 2-26 to 2-28). Smaller increases in chloride and conductivity are observed in the summer months as well. Chloride and conductivity may appear to correlate well, but by basic linear regressions fail to achieve a significant R squared value of 0.9 or greater (see Figure 2-29). However, chloride and conductivity extreme concentrations do appear to have some limited correlation (Figure 2-30). The greatest chloride and conductivity concentrations do not
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trend with alkalinity seasonally (alkalinity is at a maximum during fall months) suggesting that groundwater influence or baseflow discharge sources are not dominant. The conductivity and chloride impact appears to not be linked to upstream point source discharge increasing with decreasing baseflow (i.e. higher alkalinity). When loadings from 2006 to 2007 were evaluated, loads were greater during the periods of snowfall and freezing conditions (see Figure 2-31). Based upon these findings, the greatest chloride and conductivity concentrations appear to be linked with road and sidewalk salt application and runoff into the Brandywine Creek.
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Date
Chlo
ride
0
200
400
600
800
1000
1200
1400
1600
1800
2000C
on
du
cti
vit
yChloride
Conductivity
Ch
lori
de
(m
g/L
)
Co
nd
uc
tiv
ity
FIGURE 2-26 - Concentrations of Chloride and Conductivity at Wilmington’s
Intake (1996-2007)
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1 2 3 4 5 6 7 8 9 10 11 12
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Co
nd
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tiv
ity
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350
Ch
lori
de
Conductivity
Chloride
Co
nd
uc
tiv
ity
Ch
lori
de
(m
g/L
)
Figure 2-27 - Comparison of Chloride and Conductivity at Wilmington’s Intake by Julian Month (1996-2007)
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nd
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tiv
ity
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350
Ch
lori
de
Conductivity
Chloride
Co
nd
uc
tiv
ity
Ch
lori
de
(m
g/L
)
Figure 2-28 - Comparison of Chloride and Conductivity Concentrations at Wilmington’s Intake by Julian Date (1996-2007)
y = 33.889x0.5836
R2 = 0.6394
10
100
1000
10000
10 100 1000
Chloride
Co
nd
uc
tiv
ity
Co
nd
uc
tiv
ity
Figure 2-29- Comparison of Regression between Chloride and Conductivity Concentrations at Wilmington’s Intake by Month (1996-2007)
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y = 2.6268x + 198.81
R2 = 0.9089
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
0 50 100 150 200 250 300 350
Chloride (mg/L)
Co
nd
ucti
vit
y
Conductivity
Linear (Conductivity)
Co
nd
uc
tiv
ity
Figure 2-29 - Comparison of Regression between Chloride and Conductivity Concentrations at Wilmington’s Intake for Extreme Concentrations
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/2007
date
ch
lori
de l
oad
g/s
g/s
ch
lori
de
loa
d g
/s
Period of snowfall
Figure 2-31- Chloride Loads (Flow*Concentration) For the Brandywine Creek at the Wilmington Intake For 2006 To 2007
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Table 2-26 provides a summary of the concentrations of chloride, conductivity, and alkalinity for Wilmington’s intake between 1996 and 2007. Chlorides ranged from 10 to 313 mg/L with a median concentration of 33 mg/L (std. dev. 20 – 46 mg/L). Wilmington’s
raw water chloride concentration is therefore not considered unpolluted using the 10 mg/L
threshold established by the World Health Organization.
Table 2-26- Summary of Wilmington Intake Concentrations 1996-2007
Parameter Chloride Conductivity Alkalinity
max 313 1720 94
min 10 90 15
avg 35 269 53
median 33 270 52
stdev 13 60 9
90%tile 44 320 64
N 2449 2500 2447
It is important to note that the chlorination process and the coagulation process (using ferric or aluminum salts) will inherently increase the finished water chloride concentration. Therefore, using estimates of chloride impacts from chlorination plus a safety factor for impacts from coagulation salts, intake concentrations beyond 150 mg/L to 200 mg/L could represent periods when the finished water could approach the SMCL of 250 mg/L depending upon the impact of the chemical water treatment process. This would indicate periods of potential customer complaints or noticeable taste.
2.3.5. Alkalinity Impacts on TOC Removal and Corrosion Control
A comparison of the TOC and alkalinity data from 2004 to 2007 (199 observations) was conducted to estimate the required TOC removal for Wilmington (Figures 2-32 to 2-34). Based on these observations it is estimated that 35% of the TOC in the raw water would need to be removed over 75% of the time. 25% and 45% of the TOC would need to be removed during 11% and 14% of the time, respectively. Currently, the average alkalinity is 52 mg/L at Wilmington’s intake with a standard deviation of 9 mg/L. This means that 67% of the observations were between 61 mg/L and 43 mg/L, just under or near the 60 mg/L alkalinity threshold for TOC removal changes from 35% to 45%. If baseflow is reduced in the watershed and surface runoff is increased over time, the proportion of observations in
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the higher TOC removal categories will increase. If baseflow is protected and enhanced then lower TOC removal categories will increase. Though higher alkalinity will mean lower TOC reduction requirements it also means that TOC reduction will be more difficult to achieve. TOC reduction requirements appear to be the greatest during periods of greater surface runoff such as winter and spring when alkalinity tends to be lower and TOC can achieve higher concentrations.
Alkalinity and hardness are directly affected by baseflow from groundwater sources. Any changes in baseflow from lack of groundwater recharge of rainfall or increases in surface runoff could have significant impacts on alkalinity and hardness driving it downward. This may have a mixed impact on water treatment since lower alkalinity will make corrosion control more difficult and expensive for lead and copper control (via addition of more lime and zinc orthophosphate) while TOC removal may be easier to achieve despite higher required TOC removals. Also, the water could reduce in hardness and result in improved usage by various specialized industrial user sectors.
10
30
50
70
90
110
130
150
1 2 3 4 5 6 7 8 9 10 11 12
Date
Ino
rga
nic
s
Alk Hardness
Figure 2-32 - Comparison of Alkalinity and Hardness Seasonal Trends at the Wilmington Intake 1996-2007
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Date
Ha
rdn
es
sHardnessHard
Moderately Hard
Soft
Figure 2-33 - Hardness Trends at the Wilmington Intake 1996-2007
Required TOC Removal For Wilmington's Source Water (2004-2007)
0
1
2
3
4
5
6
7
8
9
0 10 20 30 40 50 60 70 80 90 100
Alkalinity (mg/L as CaCO3)
TO
C (
mg
/L)
45%
35%
35%
25%
Figure 2-34 - Alkalinity and TOC Removal at the Wilmington Intake 1996-2007
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2.3.6. High Turbidity Impacts on Wilmington Intake Water Quality and Treatment
An analysis of water quality at the Wilmington intake from 1996 to 2007 identified the following conditions related to intake turbidities of greater than 10 NTU:
E. coli bacteria levels in the raw water increase to undesired levels (see Figure 2-35) and research studies of Cryptosporidium in the region suggest that turbidities over 10 NTU usually have elevated levels and more frequent presence of Cryptosporidium oocysts. The LT2ESWTR monitoring to date for Wilmington is not complete enough or designed collect data to determine if the same relationships are appropriate for the Brandywine. Therefore, until enough data is available a conservative assumption that higher turbidity raw water will have greater pathogen potential should be considered.
UV absorbance and Total Organic Carbon (TOC) have the potential to (but will not always) increase to levels that represent potential challenges for Disinfection by product (DBP) precursors (see figures 2-36 & 2-37)
A strong correlation between raw water UV254 and TOC exists suggesting UV254 can be a good operational predictor of TOC levels in the raw water (see Figure 2-38).
A UV254 absorbance of greater than 0.2 would potentially result in approximately 5.5 mg/L of TOC in the raw water.
A UV254 reading of between 0.15 and 0.2 is a threshold where increased TOC and precursors have the potential to be present and additional treatment or switching to Hoopes Reservoir may be desired.
A UV254 reading of over 0.2 was almost always associated with turbidities of 10 NTU or greater suggesting this is a potential period to avoid.
Ammonia levels over 0.35 mg/L have occurred at turbidities greater than 10 NTU. Higher ammonia levels represent periods of greater chlorine demand to maintain appropriate chlorine residuals.
Switching to Hoopes for better water quality during periods greater than 10 NTU is recommended for better LT2ESWTR and Stage 2 DBPR compliance
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1
10
100
1000
10000
0.1 1 10 100 1000
Turbidity
E. co
li (
cfu
/100m
L)
E_ Coli
NOTE: Above 10 NTU, E.coli
concentrations always over recreational
value of 126/100mL.
Figure 2-35 - Comparison of E. Coli and Turbidity Concentrations at the Wilmington Intake from 1996 To 2007
Figure 2-36 - Comparison of UV 254 Absorbance And Turbidity Concentrations at the Wilmington Intake from 1996 To 2007
y = 1.2065e13.332x
R2 = 0.4166
0.1
1
10
100
1000
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
UV 254
Tu
rbid
ity (
NT
U)
Turbidity
Expon. (Turbidity)
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Figure 2-37 - Comparison of Total Organic Carbon and Turbidity Concentrations at the Wilmington Intake from 1996 To 2007
Figure 2-38- Comparison of Total Organic Carbon and UV254 Absorbance Concentrations at the Wilmington Intake from 1996 To 2007
y = 1.7876x0.1946
R2 = 0.3037
0
1
2
3
4
5
6
7
8
9
0.1 1 10 100 1000
Turbidity (NTU)
TO
C (
mg
/L)
Total Organic Carbon
Power (Total Organic
Carbon)
y = 0.0395x - 0.0186
R2 = 0.8909
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 1 2 3 4 5 6 7 8 9
TOC (mg/L)
UV
-25
4 A
bs
orb
an
ce
Ultra-Violet Absorbance @
254nm
Linear (Ultra-Violet
Absorbance @ 254nm)
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2.3.7. Pathogens
Based on the analysis of intake data, it is not uncommon for concentrations of E. coli to exceed 1,000 cfu/100mL in the raw water. However, there is no direct correlation between turbidity and E. coli suggesting that not all significant pathogen levels are associated with wet weather events. A comparison of E. coli and turbidity does reveal that when raw water turbidity exceeds 10 NTU that E. coli concentrations are always above the EPA recreational limit suggesting a challenge period for pathogens (Figure 2-40).
The lowest concentrations of E. coli appear to occur during the summer months while the highest concentrations of E. coli appear to occur during the winter and spring months (See figure 2-39). Comparisons of the ratio of the E. coli to Total Coliform were conducted to determine periods and events when bacteria were predominately that from human sewage or animal runoff. The greatest E. coli and total coliform concentrations of identical values (EC/TC ratio =1) were all observed during winter during high turbidity events. These events produced concentrations of 2,420 cfu/100mL of total coliforms and E. coli. Only 53% of the EC/TC ratios of 1 were observed during high turbidity events (turbidity > 9 NTU). The remaining events were during turbidities that were not considered influenced by wet weather events and sources. The concentrations of E. coli and Total Coliform were 200 cfu/100mL during this period and suggest that pathogen sources such as sediment regrowth/release, leaking septic systems, defective laterals, direct livestock stream access, or wastewater discharges were likely sources of pathogens.
These findings suggest that runoff and wet weather sources (such as SSOs, stormwater, sediment resuspension, and animal runoff) are potentially significant sources of pathogens at the Wilmington intake responsible for the most extreme concentrations observed, but other sources during dry weather (sediment regrowth/release, leaking septic systems, cattle access to streams, defective laterals, and sewage discharges) may have greater periods of influence. Given the inaccuracy of bacteria indicator monitoring specific monitoring using bacteria source tracking and fingerprinting methods for various pathogen sources (E. coli and Cryptosporidium) should be conducted. Given the difficulty to monitor for viruses, it is not practical to conduct studies for these pathogens, but studies using indicators such as coliphages should be considered.
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1
10
100
1,000
10,000
1 2 3 4 5 6 7 8 9 10 11 12
Date
Ba
cte
ria
(c
fu/1
00
mL
)
E_ Coli
Enterococci
Total Coliform
Figure 2-39 – Concentrations of Coliforms at the Wilmington Intake by Julian Month (1996-2007)
1
10
100
1000
10000
0.1 1 10 100 1000
Turbidity
E. co
li (
cfu
/100m
L)
E_ Coli
NOTE: Above 10 NTU, E.coli
concentrations always over recreational
value of 126/100mL.
Figure 2-40 - Comparison of E. Coli and Turbidity at the Wilmington Intake (1996-2007)
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2.3.8. Giardia and Cryptosporidium
Giardia and Cryptosporidium monitoring was conducted monthly at the intake to the three water treatment plants for the LT2ESWTR required bin classification monitoring. After a 24 month effort, the data does provide some information of value. As shown in Table 2-27, the average Cryptosporidium concentration at the Brandywine plant is three times higher than the Porter plant, while the Hoopes Reservoir has only had one Cryptosporidium detected despite having wildlife present. The Hoopes Reservoir had near pristine levels of Cryptosporidium and Giardia.
Though the variability of the Cryptosporidium testing method is significant it does suggest something is causing a potential difference (sampling method or location) between the Porter and Brandywine Intakes. It was determined that the Porter samples were collected after raw water basin settling and the Brandywine samples were collected directly at the creek. This suggests the raw water basin at Porter provides some pathogen reduction.
The mean concentration of Cryptosporidium at the Brandywine Plant was just less than the 0.075 oocysts/L cutoff for requiring additional treatment as stated in the LT2ESWTR. Therefore, if water quality continues to degrade, future resampling in 5 years during the “rebinning” process may push the Brandywine Plant over the regulatory threshold. This potential future degradation could require the Brandywine Plant to install additional treatment processes such as membrane filters or ultraviolet light disinfection to meet regulatory requirements by 2020.
Table 2-28 shows the concentrations of Giardia at the three sites. The data shows the greatest average Giardia concentration at the Porter plant almost two times greater than the Brandywine Plant despite the raw water basin settling effect. Comparison of frequency of detection can also be used as an indicator of contamination (see Figures 2-41 & 2-42). The Brandywine Plant had Cryptosporidium detected twice as often (40%) as the Porter WTP (20%). The Brandywine Plant also had Giardia detected more frequently than the Porter WTP despite Porter having a higher average Giardia concentration. Again the sampling at the Porter Plant after the settling basin compared to the sampling from the raceway at the Brandywine Plant can explain the reasons for these observations and suggests the Brandywine Plant observations of Giardia and Cryptosporidium are the most accurate reflection of intake pathogen concentrations for both plants.
It is important to note the detection rates of Cryptosporidium and Giardia suggest there is significantly frequent contamination of protozoa at the Brandywine and Porter intakes. The 20 to 42% detection rate of Cryptosporidium is similar to more contaminated streams and rivers nationwide, but may also be a result of higher filter volumes which provide lower overall concentrations. The Giardia detection rate of 85% to over 96% at the Porter and Brandywine intakes was also significantly higher than national detection rates and more similar to that of more contaminated water bodies with higher concentrations. These findings suggest some constant source of Cryptosporidium and Giardia in the watershed. Analysis of upstream disease rates is recommended and a loading analysis to predict upstream disease levels is recommended. This would include DNA fingerprinting of
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Cryptosporidium in the creek and from different sources in the watershed.
TABLE 2-27 - Comparison of Cryptosporidium Concentrations in Wilmington’s Raw Water From LT2ESWTR Monitoring (2006-2007)
Source %
positive Average
(oocysts/L) Min
(oocysts/L) Max
(oocysts/L)
Brandywine 42% 0.063 0 0.240
Porter 19% 0.029 0 0.500
Hoopes 4% 0.001 0 0.020
TABLE 2-28- Comparison of Giardia Concentrations in Wilmington’s Raw Water From LT2ESWTR Monitoring (2006-2007)
Source %
positive Average (cysts/L)
Min (cysts/L)
Max (cysts/L)
Brandywine 96% 0.310 0.020 1.70
Porter 85% 0.470 0 7.20
Hoopes 8% 0.002 0 0.02
TABLE 2-28 - Summary of Average E. Coli Concentrations in Wilmington’s Raw Water From LT2ESWTR Monitoring (2006-2007)
E. coli in raw water Brandywine Filter Plant
Porter Filter Plant
Hoopes Reservoir
Average (cfu/100mL) 139 48 2
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0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Brandywine Porter Hoopes
Source
% P
osit
ive f
or
Pro
tozo
a
Crypto
Giardia
Note: Porter collected
after RWB effluent
Figure 2-41 - Frequency of Cryptosporidium and Giardia Detection in Wilmington’s Raw Water from LT2ESWTR Monitoring (2006-2007)
0.0001
0.001
0.01
0.1
1
Brandywine Porter Hoopes
Source
Avera
ge C
ryp
to &
Gia
rdia
(#/L
)
Crypto
Giardia
Note: Porter collected
after RWB effluent
LT2EWSTR Bin 2 Crypto Cutoff
Figure 2-42 – Average Concentrations of Cryptosporidium & Giardia in Wilmington’s Raw Water from LT2ESWTR Monitoring (2006-2007)
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2.3.9. Disinfection by Product Pre-cursors
Analysis of the TOC data was presented in the alkalinity as it relates to TOC removal requirements for enhanced coagulation. It is generally preferred to have raw water TOC of less than 4 mg/L for lowest disinfection by products. However, TOC values are observed occasionally every year over 4 mg/L (see Figure 2-43). Seasonally two peaks appear in TOC. The first peak occurs during May and June and the second peak occurs during September through December (see Figure 2-43). Generally TOC is lower during the spring. UV254 follows a similar trend. These trends indicate that in the fall TOC is related to leaf and plant detritus since this is a period of warmer water and low rainfall and the May and June increases are related to the warming of the water and intense storms bringing organic material from along the near stream banks into the creek.
A correlation between raw water UV254 and TOC with an R value of 0.89 indicates a relatively strong correlation between the two parameters and that UV can be a good operational predictor of TOC levels in the raw water (see Figure 2-44). Thus a UV254 absorbance of 0.2 would potentially result in approximately 5.5 mg/L of TOC in the raw water. These findings suggest that a strategy of utilizing the Hoopes reservoir not only for turbidity, but to avoid periods of high precursors be developed or if switching to Hoopes is not an option that specific treatment techniques be developed and optimized for these periods. Preliminary data suggests that a UV254 reading of between 0.15 and 0.2 is a threshold where increased TOC and precursors are present and additional treatment or alternative sources such as Hoopes may be desired.
0
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 10 11 12
Date
TO
C m
g/L
Figure 2-43- Total Organic Carbon Concentrations in Porter Raw Water by Julian Month (1996-2007)
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y = 0.0395x - 0.0186
R2 = 0.8909
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 2 4 6 8 10
TOC (mg/L)
UV
-25
4 A
bs
orb
an
ce
Ultra-Violet Absorbance @
254nm
Linear (Ultra-Violet
Absorbance @ 254nm)
Figure 2-44 - Comparison of TOC and UV254 for the Porter Intake
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2.3.10. Nutrients
Nutrients are important to drinking water for reasons ranging from public health to taste an odor. Nitrate is an example of a nutrient with public health concerns. Nitrate is essentially harmless to most people, but is considered an acute toxin to infants under six months of age. In infants, it causes a condition known as methemoglobinemia or “blue-baby syndrome,” which can be fatal. Blue-baby syndrome is caused when bacteria in the digestive tract of infants change the nitrate into nitrite, a much more harmful substance. The nitrite then enters the bloodstream, where it can lower the blood’s ability to carry oxygen to the body, causing a blueness to the skin. Infants under six months of age are at higher risk than others because their digestive tract is not fully developed. The most obvious symptom is a bluish skin coloring, especially around the eyes and mouth. Ruminant animals (cattle, sheep) are susceptible to nitrate poisoning because bacteria present in the rumen convert nitrate to nitrite. Nonruminant animals (swine, chickens) rapidly eliminate nitrate in their urine. Horses are monogastric, but their large cecum acts much like a rumen. This makes them more susceptible to nitrate poisoning than other monogastric animals (Seif, 1998). Nitrate levels at the Wilmington intake were the lowest during the drought in 2002. Nitrate levels were at their highest in 2003 and 2004 which had greater precipitation, but still well below the nitrate MCL. This suggests that nitrate is controlled by runoff from either agricultural or stormwater sources. Regardless of the observed impacts nitrate does not exceed 3.6 mg/L which is relatively good compared to other streams and rivers in the region. However, if the limit for nitrate is changed from 10 mg/L due to blue baby syndrome and a new limit of 2 – 3 mg/L is implemented due to proposed concerns over bladder cancer then nitrate removal may need to be revisited. Nitrate and nitrite levels exhibited expected behaviors. Nitrite concentrations were greatest in winter and early spring before waters are warm and biological activity increases. Nitrite levels reach their lowest concentrations during the fall when precipitation and runoff of ammonia is lowest and biological activity diminishes. The maximum observed nitrite level of 0.36 mg/L was well below the 1 mg/L MCL suggesting nitrite is not a concern at this time. However, any consideration of switching from free chlorine to chloramines should take ammonia and nitrate levels into account because it could cause disinfection impacts as well as distribution Heterotrophic Place Count Bacteria (HPC) and biofilm growth impacts.
Ammonia concentrations tended to be the greatest during winter and spring months when biological activity is low and conversion to nitrite or nitrate is inhibited. Ammonia concentrations exceeded 0.2 mg/L at times in every season with the most frequent in winter and spring and the lowest in fall. As discussed previously ammonia levels over 0.2 mg/L can cause challenges for disinfection efficiency and chlorination. The periods of ammonia concentrations beyond 0.2 mg/L suggest impacts from upstream sources of human sewage or agriculture.
Orthophosphate is a measurement of the dissolved form of phosphorus in water and only a fraction of the total phosphorus present in water. The amount of orthophosphate in the water is dependent upon the form from the source discharging phosphorus and oxygen conditions in the water. Most environmental phosphorus is in the precipitate form attached to iron and in particulates that settle out in sediments. However if the sediment is exposed to an anoxic condition, the phosphorus can then be reduced to the dissolved form and then leach back into the water column. Orthophosphate is the phosphorus form that is most
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readily taken up by plants and algae. Thus, high levels of orthophosphate can result in relatively sudden and intense algal blooms. Normally runoff from stormwater from residential and urban areas is not as high in orthophosphate as agricultural runoff from fertilizers. Orthophosphate dose have some positive impacts. Zinc orthophosphate is added by many water suppliers for corrosion control of distribution piping systems.
Analysis of the orthophosphate measurements at the Wilmington intake observed the trend of lowest concentrations during summer months due to uptake and biological activity and higher concentrations in winter when biological activity is its lowest. There were some relatively high levels of orthophosphate observed during the spring. These spikes suggest that they are related to runoff from agricultural activities such as runoff after early manure and fertilizer spreading or tilling activities.
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Figure 2-45 – Nutrient Concentrations in Porter Raw Water (1996-2007)
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Figure 2-46 - Nutrient Concentrations in Porter Raw Water by Julian Month (1996-2007)
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2.3.11. Algae
Algae are microscopic oxygen producing photosynthetic organisms. They use light energy to convert carbon dioxide and water to sugars and cell matter. When light is not present they use oxygen and respire releasing carbon dioxide. During respiration of algae if enough are present it can actually drive the pH in the water down. The pH goes down because the algae produce CO2 and that combines with the water to form bicarbonates and carbonic acids. During photosynthesis the release of oxygen by algae (if enough are present) can raise the pH. This occurs when the oxygen reacts with the water to create hydroxyl ion (OH-) and raises the pH.
Algae can dramatically affect the pH in the water over the course of a day affecting coagulation chemistry. Certain algae called diatoms actually can cause head loss and filter clogging problems. Other algae such as blue green algae can release taste and odor causing chemicals at the part per trillion levels that produce taste and odor complaints by customers. There are a growing number of reports that algae such as dinoflagellates release toxic chemicals that have killed animals drinking from lakes and ponds. The red tide is an example of the impacts of the toxic effects of dinoflagellates. Therefore, algae can have routine nuisance impacts costing water suppliers time and money to treat the problem as well as more dramatic impacts under extreme conditions.
Two sampling events were conducted by COW in spring 2006 and 2007 and sent to a laboratory for algae identification and counting. The samples included Porter and Brandywine raw water. Based on analysis of these samples the following was determined:
Filter clogging algae are present and there is evidence of algal blooms occurring based on online DO and pH data (Table 2-30)
Over half of the algae detected in the detailed samples (by frequency, not count/concentration) were filter clogging or nuisance algae (Figure 2-47).
Approximately one third to one half of the algae concentration observed from individual samples were filter clogging or nuisance algae.
The Brandywine Membrane Filtration Pilot Plant must consider these impacts during studies
Geosmin and MIB samples collected with the algae samples only detected geosmin once (7/21/06 at 3.5 ng/L). All other samples were non detect for MIB and Geosmin. Once concentrations cross the 10 ng/L threshold powdered activated carbon would need to be added at the WTP to avoid potential taste & odor complaints. (The normal human threshold is 10 ng/L).
The presence of these algae suggest a potential for future taste & odor issues
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Table 2-30 – Summary of Algae Types and Frequency Detected in Wilmington’s Raw Water In 2006 & 2007
Algae name # times detected %
detected Algae Type/Importance
Gloecystis 1 4% Unknown
Unidentified flagellates 5 20% Unknown
Achnanthes 1 4% Algae growing on surfaces
Gomphonema 1 4% Algae growing on surfaces
Microspora 1 4% Algae growing on surfaces
Cocconeis 2 8% Clean water algae
Navicula 6 24% Clean water algae/filter
clogging algae
Chlorella 1 4% Filter clogging algae
Nitzschia 1 4% Fresh water pollution algae
Lyngbya 2 8% Fresh water pollution algae/ blue-green algae/T&O algae
Oscillatoria 1 4% Fresh water pollution algae/ blue-green algae/T&O algae
Scenedesmus 1 4% Surface water algae
Stauroneis 1 4% Surface water algae
Synedra 1 4% T & O algae
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Figure 2-47 – Frequency of Algae Types Detected in the Brandywine Creek at Wilmington’s Intake
Breakdown of Algae Types Detected In Wilmington Raw Water
filter clogging/T&O algae
56%
Surface growing algae
12%
Other
32%
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2.3.12. Trace Organics
Trace organics include pharmaceuticals and personal care products. Currently some of the trace organics are being investigated for potential as endocrine disrupting compounds (EDCs). This subset of the trace organics that have been suggested to have the potential for environmental (aquatic life) or health effects at very low levels (1 – 10 ng/L) are of the most concern to water suppliers. Studies by the American Water Works Foundation show that these compounds are not easily removed by the water treatment process. New studies are currently underway to examine the toxicological relevance of these compounds in drinking water. Preliminary findings of most research on pharmaceuticals (one of the groups of trace organics) suggests that a person would need to drink 8 glasses of water per day for thousands of years to get the same dose as an infants dose of Tylenol. Thus, attention is turning towards personal care products and items such as plasticizers, flame retardants, and chemicals which mimic estrogen due to potential endocrine effects at very low concentrations. It is clear there is growing public and media pressure on the issue of Pharmaceuticals in drinking water. In March 2007, the Associated Press ran an in-depth three part investigative article on this issue. This touched off local media and political inquiries into the issue.
Before the recent media coverage of this issue, the City of Wilmington in 2007 initiated a quarterly sampling program with USGS using non standardized research analytical methods to identify trace organics in the Brandywine Creek at Chadds Ford. Part of the reason for this study was due to the fact that trace organics can serve as good tracers to identify potential sources impacting the water supply for other contaminants. For example if livestock related chemicals are found, then it lends strength to prioritizing agricultural controls. The monitoring analyzed for 54 different pharmaceutical compounds. Only 12 pharmaceuticals were detected as shown in Table 2-31. Additional monitoring will be conducted in Chadds Ford and the East and West Branch of the Brandywine Creek to help identify sources.
Table 2-31 – Pharmaceuticals Detected in the Brandywine Creek at Chadds Ford
Note: Concentrations in ppb or ug/L
The preliminary results of the sampling did identify that the largest concentrations of
Med identified Description Concentrations
Acetaminophen Tylenol 0.014 - 0.018
Caffeine coffee byproduct 0.016 - 0.047
Carbamazepine anticonvulsant 0.013 - 0.046
Cotinine nicotine byproduct 0.015
Diltiazem blood pressure 0.003
Diphenahydramine cold medicine / allergy 0.002
Sulfamethoxazole antibacterial 0.016 - 0.035
Azithromycin antibiotic - human 0.035
Roxithromycin antibiotic - human 0.073
Sulfachloro-pyridazine antibiotic - livestock 0.006
Tylosin antibiotic - livestock 0.542
Trimethroprim antibiotic - human 0.007 - 0.015
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antibiotics were from livestock suggesting agricultural runoff controls are a greater priority. The detection of the antibiotics also suggests that studies of antibiotic resistant bacteria may be useful in identifying sources of pathogens in the watershed. The expected low level identification of human medicines also confirms that wastewater discharges do contribute trace organics to the water supply and that other trace contaminants such as pathogens may have the potential to be delivered by wastewater as well downstream to Wilmington’s water supply. Further study is needed upstream of Chadd’s Ford to help isolate the various geographical areas and sources/activities of the trace organics.
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2.3.13. Metals
Figures 2-48 to 2-50 show the observed metals data for the Wilmington intake. Zinc concentrations were the greatest during 1999. In general, zinc concentrations are greater during winter and spring and lowest during the fall. It is unknown if this is related to precipitation or release of zinc from corrosion of piping systems. None of the zinc concentrations were within a factor of 10 of the secondary MCL.
Iron concentrations were the greatest during the summer and fall when precipitation is low and water temperatures are higher and more baseflow from groundwater occurs. This results in a greater release of iron from geological formations. Iron concentrations were the highest in the spring when surface runoff was dominant. During all months of the year iron concentrations at the Wilmington intake were great enough to exceed the secondary MCL.
Based on these findings, the dominant source of iron is in crustal forms from groundwater sources, but extreme weather events can produce high iron concentrations at times. Since iron concentrations can exceed the secondary MCL in the raw water, oxidation of the iron must be conducted prior to filtration in order to remove it properly in the drinking water treatment process.
Manganese concentrations were the greatest during the late spring and early summer when surface runoff was dominant. Manganese concentrations were the lowest in the fall when precipitation is low and water temperatures are higher and more baseflow from groundwater occurs. This results in a greater release of manganese from geological formations. During all months of the year manganese concentrations at the Wilmington intake were great enough to exceed the secondary MCL.
Based on these findings, the dominant source of manganese is in surface forms impacted by runoff and precipitation. Since manganese concentrations can exceed the secondary MCL in the raw water, oxidation of the manganese must be conducted prior to filtration in order to remove it properly in the drinking water treatment process.
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0.001
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Figure 2-48 - Total Iron Concentrations in Porter Raw Water by Julian Month (1996-2007)
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Figure 2-49 - Total Manganese Concentrations in Porter Raw Water by Julian Month (1996-2007)
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Figure 2-50 - Zinc Concentrations in Porter Raw Water by Julian Month (1996-2007)
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2.3.14. Long Term Water Quality and Historical trends 1979-2007
Long term trends allow the ability to determine the past, current, and potential future water quality of the watershed and to evaluate how changes in regulation, industry, and development/land use have impacted the watershed. This is valuable information that can inform which areas of the past and current watershed protection efforts have been successful and what gaps remain.
The identification of long term trends also allows for prediction of future water quality. Specific trends for certain parameters provide identification of potential contaminant sources of concern for future mitigation and protection planning work. This data combined with the seasonal analysis (Julian calendar analysis) will provide additional perspective to contaminant issues and sources and may even provide some indication of general geographic areas within the watershed for focused data collection, monitoring, or protection/mitigation activities.
It was determined that the Lower Brandywine Creek would be the best area to receive the sum of all the changes in water quality and pollution activities in the watershed and would serve as the best starting point to identify any potential long term trends. The EPA STORET water quality data for 52 parameters for the period from 1967 to 1999 at five locations on the Lower Brandywine was obtained from DNREC in June of 2007 for long term trend analysis. The first step in this process was to determine through a simple screening process if any potential trends could be observed and comparison with trends observed in USGS studies from 1981 to 1997 in the Upper Brandywine. Once a potential trend was observed, the data was then compared to data from the City of Wilmington intake for the period from 1997 to 2007 to see if the same trend continued. This allows for a later analysis that compares the long term trends analyzed for upstream locations on the Brandywine by USGS. If the same trends for the same parameters in the lower Brandywine in Delaware match that for the upper Brandywine or a specific branch, geographical isolation of sources or land use activities for source water protection planning may be possible. The locations provided in the data from DNREC/STORET included the following five locations in Table 2-32.
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Table 2-32 – Locations of DNREC/STORET Long Term Trend Data Analysis from 1967 to 1997
AGENCY STATION LAT LONG USGS HUC
LOCATION NAME
21DELAWQ 104011 394532 753315 2040205 BRANDYWINE CREEK, FOOT BRIDGE IN BRANDYWINE PARK
21DELAWQ 104021 394613 753445 2040205 BRANDYWINE, RD 279 BRIDGE, DU PONT EXP STATION
21DELAWQ 104031 394720 753432 2040205 BRANDYWINE, DU PONT STATION AT HAGLEY MUSEUM
21DELAWQ 104041 394749 753431 2040205 BRANDYWINE CREEK AT ROCKLAND BRIDGE
21DELAWQ 104051 395015 753445 2040205 BRANDYWINE CREEK AT SMITH BRIDGE
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Figure 2- 51 - Sampling Locations in the Lower Brandywine Used In the Trend Analysis
As shown above the five sampling locations cover a distance of roughly 12 kilometers starting at the upstream location at the Delaware State Border, bracketing the Dupont Experimental Station, and extending down to the City of Wilmington’s intakes.
Data from all five locations was pooled in order to accommodate for missing time periods in data sets and to cover seasonal gaps in monitoring. It was assumed by pooling the data that the water quality at the various locations is statistically identical or at a minimum not statistically significantly different. This assumption remains to be tested and will be tested in later phases for any significant observed trends.
A total of 52 parameters were examined for potential trends. Only 17 parameters had sufficient data and were of relevance to drinking water quality. The final parameters analyzed are provided in Table 2-33 below.
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Table 2-33 – Parameters Examined for Long Term Trends in Delaware
Inorganics Pathogens Nutrients Metals Organics
Dissolved Oxygen Enterococcus Total
phosphorus Total Iron Total organic
carbon
pH Fecal coliform Total
orthophosphate Total
Manganese
Chloride Fecal
streptococcus Ammonia (total NH3 and NH4)
Conductivity
Nitrate (total NO3 and total
NO3+NO2)
Alkalinity
Hardness
Temperature
The analytical methods, detection limits, recovery, precision, and variability for many water quality parameters have changed substantially since 1970. Therefore, when conducting a historical trend analysis, it is important to remember that not all decreasing or increasing trends are related to real water quality changes from pollution sources and could be an artifact of the analytical process. Once trends are observed and even if plausible explanations or sources are available, future analysis will need to be conducted to determine the types and time period that different analytical methods were used and their potential impact on the observed data and trends.
Comparison of probe, field, and lab data are also always an element to consider when conducting historical trend analyses. The data from any of the three methods for the same parameter can observe similar or different trends. Therefore an understanding of the shortcomings and inaccuracies of these methods is important to determine which measurement is most likely the true measurement at the location and representative of what is occurring.
The following was observed in the Lower Brandywine from the potential trend analysis:
Chloride and conductivity appear to have the most pronounced and continuous increasing trends from the early 1970s to current periods in the Lower Brandywine. There is no indication that this trend is “leveling off” or diminishing. As mentioned in previous analysis regarding the Wilmington intake water quality data, it appears that these concentrations are related to road salt runoff, road salt runoff accumulation in the watershed and groundwater, and potentially even the effects of increased irrigation (from landscaping, farming, sewage disposal) causing “salting”
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effects on surface waters.
Alkalinity and hardness appear to have increasing trends that mirror that of chloride and conductivity, but appear to be related to groundwater and base flow changes. As mentioned in previous memos regarding analysis of Wilmington intake data, increasing alkalinity will affect the requirements for TOC removal by the Wilmington water treatment plants and have potential impacts on future water treatment designs, operations, and distribution system corrosion control approaches.
Total phosphorus appears to be decreasing while total orthophosphate concentrations remain relatively unchanged suggesting that any improvements in phosphorus reduction in the watershed will need to be significant in order to have an effect on orthophosphate concentrations and thus ecological activities influenced by orthophosphate uptake in the water column (i.e. algal growth).
Nitrate concentrations appear to be have increased since the 1970s, but appear to be leveling off in recent years while ammonia concentrations have decreased historically (are they stable?). This appears to be related mainly to the advent of secondary wastewater treatment since the trend starts in the mid 1980s when most sewage treatment plants were required to enact secondary wastewater treatment. TKN appears to be decreasing historically, but leveling off in recent years.
Dissolved oxygen concentrations appear to have some limited decreasing trend since the mid 1980s. This appears to coincide with changes to secondary wastewater treatment suggesting that nitrogenous biological oxygen demand (NBOD) from upstream wastewater discharges in Pennsylvania, may have some potential role in the slightly decreasing dissolved oxygen trend in the Lower Brandywine. Future data needs to be collected to confirm these observations and determine their validity. In addition, calculations on time of travel from upstream sewage treatment plants during a variety of base flow conditions needs to be examined to determine if their sufficient time for NBOD exertion to occur. Given the variety of small and large historic mill dams and impoundments along the Brandywine, especially in the Lower Brandywine, there may be some localized NBOD effects from these impoundments “holding” water longer than main stream channel water. There are no major changes in the extremes or trends of other algae related parameters such as water temperature and pH concentrations to suggest that the downward DO trend is algae related at this time, but it does not rule out algae growth and population type as a possible factor.
There were no discernible historical trends observed for total organic carbon, bacteria/pathogens, total iron and manganese, temperature, and pH. Trends may be occurring, but analytical method variability, analytical detection limits, analytical method changes, and frequency/seasonality of monitoring may not have been able to detect them.
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Table 2-34 – Summary of Historical and Current Water Quality Trends in the Chester County Portion of the Brandywine Creek Reported in Various USGS Studies
Parameter
Historical Trend (pre-
1990) Current Trend
(post 1990)
USGS Trend (1981-1997)
Potential for
Negative Impacts Notes:
Chloride Increasing Increasing NA Yes Most notable increasing
trend in watershed
Conductivity Increasing Increasing Increasing Yes Most notable increasing
trend in watershed
Alkalinity Increasing Increasing NA Yes related to base flow changes potentially
Hardness Increasing Increasing NA Yes related to base flow changes potentially
Total Phosphorus Decreasing Decreasing Decreasing No
Orthophosphate Decreasing Stable NA Yes dissolved phosphorus
can impact algal growth
Nitrate Increasing Stable Increasing No
Ammonia Decreasing Decreasing Decreasing No
TKN Decreasing Stable NA No
Dissolved Oxygen Increasing Increasing/Stable Increasing No Positive trend
2.3.15. Spatial Comparison of Water Quality Trends
In addition to the Lower Brandywine Trend analysis another analysis of long term trends from 1981-1997 was conducted for Chester County (Reif, 2002). Increasing trends in nitrate and specific conductance were observed while decreasing trends in phosphorus and ammonia were observed. Increases in nitrate and specific conductance were attributed to wastewater discharge and conversion of ammonia. Decreases in phosphorus were attributed to reduced agricultural activity, improvements in wastewater treatment, and elimination of phosphates in detergents. Increases in dissolved oxygen during this period were also attributed to reduced agricultural impact and improved agricultural management and wastewater treatment improvements. Evaluation of bed sediment data suggests that pesticides have decreased or are of limited presence in the Brandywine due to reductions in
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agriculture use and outlawing of the substances.
Trends are not necessarily observed watershed wide homogeneously in the Brandywine Creek, but can have spatial differences. According to USGS, (Reif, 2002), statistical analysis showed 10 of 11 sites in the Brandywine observed increasing trends in specific conductance and 8 of 11 sites observed increasing trends in nitrate. Concentrations of phosphorus and ammonia went down or stayed the same at 4 of 11 and 3 of 11 sites respectively in the Brandywine from 1981-1997. The specific sites with these trends were not identified by USGS in the report.
Comparison of overall contaminant concentrations also has an impact on the trends, especially if one area of the watershed is significantly higher or lower. The West Branch and East Branch of the Brandywine have roughly similar concentrations of nitrate, though West Branch has all increasing trends of nitrate while the East Branch has some increasing trends. Specific conductance increases suggest that in addition to nitrate that sodium, chloride, and TDS may be increasing in these areas. The USGS study suggested that trends in nutrient concentrations follow a spatial pattern related to land use in Chester County.
The USGS observed most dramatic improvement in water quality were the trends for phosphorus, ammonia, and dissolved oxygen. For example, data from 3 monitoring stations since 1972 indicate the concentrations of minimum dissolved oxygen have increased over time. In 1997, there only were 3 days when the minimum concentration of dissolved oxygen was below 5.0 mg/L on the East Branch Brandywine Creek below Downingtown compared to 103 days in 1981 (Reif, 2002).
2.3.16. Comparison of Water Quality by Land use, Location, and Weather
There is no single report that compares the water quality at different locations in the watershed. This is mainly due to the fact that there are only a handful of sites where comparative data is available and usually beyond basic parameters there are less than 25 observations. Thus, a detailed statistical analysis comparing the water quality between different locations in the watershed is not a feasible exercise, but could be possible in a future effort. Therefore, it is suggested that future watershed monitoring programs become synchronized in order to conduct a geographical comparison of a variety of key parameters.
Since a true statistical comparison of various locations in the watershed was not feasible given the data management and comparison issues another method of comparison was performed utilizing comparisons from past water quality studies. The comparisons are conducted by using data and graphs from studies conducted by USGS to examine the differences in stream water quality samples in the Brandywine for different land uses and weather conditions. All graphs in this section are from the various USGS reports.
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2.3.16.1. TSS and Nutrients Spatial Comparison
In previous studies (Keorkle and Senior, 2002), it has been found that the TSS during dry weather is always below 20 mg/L and usually in single digits values. Overall wet weather TSS values were roughly 100 times higher than during dry weather for all land uses except for forested lands.
During dry weather there only appears to be higher TSS in the main stem, but this could be due to the many dams and fluvialgeomorphological differences between the branches and main stem and less related to land use.
During wet weather the sampling location representative of a majority residential unsewered land use observed the highest median TSS concentrations closely followed by agricultural livestock and row crop land use/watershed station. Residential sewered and main stem mixed use lands produced substantially lower median TSS values with the lowest TSS values observed in the forested land use areas. These observations were not unexpected given that residential development and agricultural activities can create the greatest streambank encroachment, erosion, and degrading activity.
During base-flow periods agricultural row crop areas, agricultural livestock areas, and residential unsewered areas observed higher levels of nitrate over 3 mg/L. These impacts were observed further downstream at the main stem mixed use sites and appear to be dominant. Residential sewered and forested land use stations observed ranges of concentrations that were roughly similar (range: 0.5 to 2 mg/L).
During wet weather nitrate concentrations generally decreased at all sites or were not substantially different. Overall agricultural row crop, agricultural livestock, and residential unsewered continued to be the dominant land uses with the greatest nitrate concentrations compared to other locations. The manure and fertilizer runoff and local impact on groundwater from agricultural activities is an obvious source of nitrate in the stream. The source of the nitrate concentrations from residential unsewered areas is suspected to be from septic systems in failure or impacting local groundwater systems. It has been well documented in other states and within Delaware that there are a significant number of failed septic systems reported and estimated (University of Delaware, 2007).
Total and dissolved ammonia was the greatest at agricultural livestock and residential unsewered areas during base flow periods. Agricultural row crops observed the greatest increase in total and dissolved ammonia concentrations from baseflow to stormflow periods which is suspected to be mainly due to manure and fertilizer. Agricultural livestock land use also saw a slight increase in concentrations during storm flow periods. The other stations and land use did not see any increase from base flow to storm flow periods.
The agricultural livestock station observed the greatest concentrations of total and dissolved phosphorous compared to other stations. Residential sewered and forested areas observed the lowest total phosphorus concentrations during baseflow and stormflow. Residential unsewered and forested areas observed the lowest orthophosphate concentrations during baseflow and stormflow. Dissolved orthophosphate concentrations
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increased significantly during stormflow at livestock agricultural areas, but remained relatively unchanged at other stations. Total phosphorus increased by a factor of 10 from baseflow to stormflow periods at the agricultural livestock, agricultural row crop, and residential unsewered locations.
Overall, the data from previous studies by USGS suggests that regardless of weather condition agricultural and residential unsewered areas are major contributors of TSS and nutrients.
2.3.16.2. Bacteria Spatial Data Comparison
There has been considerable study of the bacteria concentrations and hypothesis as to its sources in the Brandywine Creek Watershed to date. However, there have not been any studies using advanced methods such as DNA fingerprinting, genetic typing, or antibiotic resistance to conclusively determine bacteria sources in the watershed. Therefore, geographical, temporal, and land use based comparisons are the only tools available to identify potential sources of bacteria.
A study by USGS (Town, 2000) was conducted that examined the elevated bacteria concentrations during base flow and stormflow to indicate pollution from point and nonpoint sources. The study concluded that during base flow, elevated bacteria concentrations in the Brandywine Creek appear to come from nonpoint sources such as contaminated ground water, or from farm animals and wildlife entering and leaving waste in the stream. It also concluded that during stormflow, land-surface runoff, a nonpoint source, is the causal agent for the elevated bacteria concentrations in all of the subbasins. This information is further corroborated by a USGS study (Cinotto, 2005) of bacteria sources in 2005 that suggested nonpoint sources as well. The Cinotto study concluded that previously suspected sources of elevated bacteria concentrations, such as wastewater treatment facilities and on-lot sewage disposal systems, were not found to directly contribute to increased bacterial concentrations observed within the study area of the West Branch Brandywine Creek. Cinotto suggested that the primary sources of elevated bacteria concentrating throughout the study area were generally found to be related to natural processes occurring within the environment and anthropogenic influences centered around urban and industrial runoff issues. The combined conclusions of these studies suggest that livestock, wildlife, or urban/suburban runoff with bacteria regrowth as the main sources of bacteria in the watershed.
The USGS study concluded (Town, 2000), that the factors affecting bacteria concentrations in the Brandywine Creek Basin include nonpoint sources, stormflow, reservoirs, and seasonality. Suspected nonpoint sources included agriculture, ground-water contamination (residential septic systems or leaking landfills), urban/residential activities, resident wildlife, and land-surface runoff. As was expected, bacteria concentrations are higher in stormflow than in base flow because the runoff washes the land surface, and overland runoff transports bacteria (mostly attached to particulates) into the stream.
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The observed concentrations of bacteria in the USGS studies suggest that the West Branch has the highest base flow and storm flow concentrations of bacteria. This is suspected to be linked to the greater agricultural land use activities in the West Branch. This is further shown by USGS comparisons of median concentrations of fecal coliform bacteria from 1998 to 1999 (Table 2-35) and 1973 to 1999 where fecal coliforms were highest on the West Branch at Modena and Honey Brook and lowest on the Main stem at Chadds Ford. The East Branch at Downingtown had the greatest range in bacteria concentrations.
Table 2-35 –Comparison of Spatial and Weather Related Fecal Coliform Concentrations in the Brandywine Creek Reported by USGS (Town, 2000)
Baseflow Fecal Coliform
Stormflow Fecal Coliform
USGS Station ID
Site Name Range Median Range Median
1480300 West Branch Brandywine Creek near
Honey Brook 63-10,000 4,500 1,100-610,000 12,000
1480500 West Branch Brandywine Creek at
Coatesville Reservoir 2-1,800 410 3,700-16,000 7,200
1480617 West Branch Brandywine Creek at
Modena 6-4,400 940 2,700-15,000 6,000
1480870 East Branch Brandywine Creek below
Downingtown 80-8,000 590 1,400-12,000 4,500
1418000 Brandywine Creek at Chadds Ford 2-2,200 110 160-6,700 2,200
Source: Data reported in Town, 2000
The USGS study (Town, 2000) suggested that the tributaries on the West Branch that contribute elevated bacteria concentrations to Brandywine Creek during base flow include Birch Run, Rock Run, Doe Run, Little Broad Run, Broad Run, and Two Log Run. During stormflow, Buck Run also contributes elevated bacteria concentrations. The tributaries on the East Branch that contribute elevated bacteria concentrations to Brandywine Creek during base flow include Beaver Creek, Uwchlan Run, and Taylor Run. During stormflow, Marsh Creek, Culbertson Run, and Valley Creek were also determined to contribute elevated bacteria concentrations. Pocopson Creek, the only tributary on the main stem that was evaluated, contributed bacteria concentrations to the Brandywine Creek during base flow and stormflow.
Comparison of bacteria concentrations at sites above and below each of the three reservoirs in the Brandywine Creek Basin (Chambers Lake, Rock Run, and Marsh Creek Reservoirs) by USGS (Town, 2000) observed that bacteria concentrations in the streams that flow from the
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reservoirs are lower than bacteria concentrations in the streams that flow into the reservoirs. USGS suggested that this phenomenon is most likely due to the dilution of the small stream bacteria concentrations in the large volume of water in the reservoir and not due to any specific reduction mechanisms.
Seasonality plays a role in the concentration of bacteria in Brandywine Creek. During March, April, May, October, and November, water temperatures and bacteria concentrations are lower in the Brandywine Creek than during June, July, August, and September. This lends further credence to the bacteria regrowth and algae impacts on bacteria concentrations suggested by Cinotto.
The USGS that compared the impacts of different land use on bacteria concentrations showed no significant differences between fecal coliform concentrations in agricultural, forested, residential or mixed subbasins during base flow and stormflow (Town, 2000). However, sites in forested subbasins had a greater range in bacteria concentrations than did sites in agricultural, residential, or mixed subbasins. These results were in substantial contrast to the observed water quality data.
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Table 2-36 –Summary of Tributaries in the Brandywine Creek Watershed with Elevated Bacteria Concentrations Reported by USGS (Town, 2000)
Elevated Concentrations Observed During
Tributary Branch Baseflow Wet Weather
Birch Run West X
Rock Run West X
Doe Run West X
Little Broad Run West X
Broad Run West X
Two Log Run West X
Buck Run West
X
Beaver Creek East X
Uwchlan Run East X
Taylor Run East X
Marsh Creek East
X
Culbertson Run East
X
Valley Creek East
X
Pocopson Creek
Main
stem X X
2.4. Potential Sources of Contamination Analysis
2.4.1. Point Sources Inventory
Combining information from the states of Delaware and Pennsylvania for a comprehensive point source inventory was a challenging effort since the two states house information on different types of point sources in different places/programs and in formats that are not easily merged. Therefore, the first step in assessing the scope and location of point sources was to start with the review of the point sources from the Source Water Assessments
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conducted in the watershed. The Wilmington source water assessment was expected to provide the closest proximity sources and includes a 196 square-mile portion of the watershed (60%) and extends upstream starting at the Wilmington intake in Delaware and up to the first Pennsylvania intakes along the East Branch of the Brandywine Creek at West Chester and the West Branch of the Brandywine Creek at Coatesville. The Pennsylvania SWAP program conducted source water assessments upstream for the West Chester and Coatesville intakes for the remaining 129 square miles of the watershed (40%).
As described in the Delaware SWAP (University of Delaware, 2002), the delineated source water areas for surface water intakes were separated into Level 1 and Level 2 areas. The Level 1 areas were the lands closest to the main stream and its tributaries. These lands were expected to have the greatest impact on water quality. They included the Level 1A areas defined as the 100-year floodplain and erosion-prone slopes adjacent to the floodplain and the Level 1B areas defined as a buffer area of 200 feet on both sides of the stream. The erosion prone slopes were only designated on the Delaware portion of the watershed and were obtained from the New Castle County Water Resource Protection Area program developed years ago to protect public drinking water sources in New Castle County. The entire watershed area upstream of the intake is labeled as the Level 2 area (196 square miles). In the SWAP potential contaminants in the Level 2 area were important to water quality, but their impacts were considered lesser than those located in Level 1 areas because of the greater distance they must travel to enter a stream.
The Delaware Source Water Assessment Plan separated discrete sources into the following categories following a category scheme established by the State DNREC:
Hazardous Substance Sites (Superfund and SIRB)
Large On-Site Septic Systems
Underground Storage Tanks/Leaking UST
Waste Water Spray Irrigation
Landfills/Dumps Waste Sludge Application
NPDES Waste Water Discharges Confined Animal Feed Operations
Tire Piles Combined Sewer Overflows
Hazardous Waste Generators
Dredge Spoils
Toxic Release Inventory (TRI) Sites Domestic Septic Systems
Salvage Yards SARA Title III Sites
Pesticide Loading & Mixing Areas
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The existence of a discrete source doesn’t necessarily mean it was discharging a contaminant and even if there was a discharge that may be regulated by a permit. However, its location within a source water area may provide a threat to the drinking water source. The Delaware DNREC developed an extensive database (called the Site Index Database) of discrete sources and determined the relative risk that almost every discrete source in Delaware poses to a variety of media including surface waters.
2.4.1.1. Summary of Delaware SWAP Discrete Source Inventory
Approximately 433 point sources were identified in the 196 square mile area upstream from the Wilmington intake SWAP. In the Delaware portion of Wilmington’s Brandywine Creek intake delineated source water area, which were closest to the intake, there were 24 discrete sources in the Level 1 area and 287 discrete sources in the Level 2 area (Table 2-37). In the Pennsylvania portion of this delineated source water area the contaminant inventory was incomplete. There were a total of 122 known discrete sources with the majority of them associated with wastewater or stormwater management, including NPDES discharges, spray irrigation sites, and large septic systems. There were 72 discrete sources in the Level 1 area with all but one associated with stormwater or wastewater discharges. There were 50 discrete sources in the Level 2 area. It is important to note that the inventory compiled by Delaware stopped before reaching the majority of the populated areas upstream of West Chester, Coatesville, and Downingtown since PADEP was continuing the inventory beyond that point for those intakes.
It is also important to note that many of the PA inventories did not have data available from PA and could have missed significant potential sources. An example of this missing information is aboveground and underground storage tanks (AST/UST). A brief review of the AST/UST records for Chester County identified another 1270 AST/UST that may or may not reside in the watershed. Some of these tanks have the potential to store up to 30,000 gallons of chemicals including fuel oil, gasoline, diesel fuel, and hazardous substances. Section 3 in this report will discuss the potential impacts from accidents and tanks. From the upstream SWAP reports the total point sources in the entire watershed upstream of Wilmington is most likely double that reported in the Wilmington SWAP.
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Table 2-37 – Summary of Delaware SWAP Discrete Source Inventory
Discrete Site Type
Brandywine Creek at
Wilmington DE PA
DE PA Level
1 Level
2 Level
1 Level
2 total
Hazardous Substance Sites(Superfund and SIRB) 4 * 1 3 * * 4
Underground Storage Tanks 259 * 19 240 * * 259
Landfills/Dumps 0 9 0 0 1 8 9
NPDES Wastewater Discharges** 3 61 3 0 61 ** 64
Tire Piles 0 * 0 0 * * 0
Hazardous Waste Generators 42 * 0 42 * * 42
Toxic Release Inventory (TRI) Sites 2 * 1 1 * * 2
Salvage Yards 0 * 0 0 * * 0
Pesticide Loading, Mixing Areas 0 * 0 0 * * 0
Large On-Site Septic Systems 0 35 0 0 7 28 35
Waste Water Spray Irrigation 1 17 0 1 3 14 18
Waste Sludge Application 0 * 0 0 * * 0
Confined Animal Feed Operations (CAFOs) 0 * 0 0 * * 0
Combined Sewer Overflows 0 * 0 0 * * 0
Dredge Spoils 0 * 0 0 * * 0
Domestic Septic Systems 0 * 0 0 * * 0
SARA Title III Sites * * * * * * 0
Total 311 122 24 287 72 50 433
* Limited or No Data Available from PA.
Table 2-38 provides a list of the point source types identified in the other source water
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assessments for water intakes upstream of Wilmington. The evaluation of top priority sources of pollution from the prior SWAP reports in Section 1.3 shows that upstream discharges were the most important point sources due to their potential for impact during dry weather and plant failures/accidents. The reports all gave storage tanks and other point sources lower priority over non-point sources such as urban/suburban stormwater runoff, agricultural runoff, and transportation corridor accidents. These rankings were created by program officers with on the ground field knowledge of the facilities and thus are considered the best available information and judgement related to their potential for concern. Though the ranking schemes were based on a number of factors, emergency planning prioritization for these point sources should be conducted that will prioritize which sites may have the greatest impact during an emergency/accident that has a low likelihood of occurrence, but a high potential impact. This separate emergency prioritization would be used for emergency planning purposes only, but may help aid in regulatory inspection programs and notification requirements in permits and improved first responder training and education.
Combining the point source inventory information from the upstream SWAPs and the other available GIS coverages from PA and DE, the total estimated number of relevant point sources is 706 (See Table 2-39). This is almost twice the original estimate of point sources in the Wilmington SWAP in 2002. The location of these potential sources is in Figure 2-52.
Table 2-38 – Summary of SWAP Point Source Inventories for the Brandywine Creek Watershed
SWAP Wilmington Downingtown Coatesville West
Chester Total
UST 259 24 8 291
TRI 2 3 0 5
RCRIS 42 16 6 64
PWS ID'd 0 19 19 38
NPDES/PCS 64 6 1 71
Mines 0 1 4 5
Superfund/SIRB 4 4
Landfills/Dumps 9 9
Spray Irrigation 18 18
Septic Systems 35 35
TOTAL 433 69 38 325 865
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Table 2-39 – Summary of SWAP Point Source Inventories for the Brandywine Creek Watershed from Available GIS Coverages
Discrete Site Type
PA part of COW SWAP
GIS
DE part of COW SWAP
GIS
PA UST GIS
coverage (via
WRA)*
PA NPDES
GIS coverage
(via WRA)**
PA HWG GIS
coverage via WRA
PA Water Resources
GIS Coverage
(via WRA) subtotal
Hazardous Substance Sites(Superfund and SIRB) 4 4
Underground Storage Tanks 148 109 257
Landfills/Dumps 12 12
NPDES and Wastewater Discharges 129 3 93 22 247
Tire Piles 0
Hazardous Waste Generators 41 3 44
Toxic Release Inventory (TRI) Sites 2 2
Salvage Yards 0
Pesticide Loading, Mixing Areas 0
Large On-Site Septic Systems 35 77 112
Waste Water Spray Irrigation 20 7 27
Waste Sludge Application 0
Confined Animal Feed Operations (CAFOs) 1 1
Combined Sewer Overflows 0
Dredge Spoils 0
Domestic Septic Systems 0
SARA Title III Sites 0
Total 706
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Figure 2-52 – Location of Potential Point Sources in the Brandywine Creek Watershed
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2.4.1.2. NPDES Dischargers
In the source water assessments were 64 known discharges with NPDES permits in the watershed as of 2003. The largest 30 NPDES dischargers are shown in Table 2-39. Figure 2-52 shows their location. The total volume discharged to the watershed in 1998 was estimated to be 5.3 billion gallons per year or 12.9 million gallons per day on average.
Point sources can have some effect on the water quality in the watershed during baseflow periods. Under certain conditions NPDES discharges have been reported to make up over 15% of the flow in the Brandywine Creek (BVA, 1999). These discharges cannot be ignored since they affect the baseline water quality in the watershed during non rain event influenced period (roughly 60% of the year).
Though NPDES discharges have permit requirements to reduce specified pollutants to prevent water quality problems, the NPDES and TMDL process of the Clean Water Act does not specifically regulate many of the same water quality parameters that are regulated by the Safe Drinking Water Act. For example, Cryptosporidium does not have a federal or state water quality standard though water suppliers are regulated based upon the concentrations in their raw water. Many of the emerging contaminants that water suppliers are concerned about are not regulated by any state and federal agencies in the region including taste and odor compounds, pharmaceuticals, and personal care products. Regardless of the gaps between the CWA and SDWA, the NPDES process does provide opportunities and mechanisms to ultimately address nutrients, TSS, TDS, and TOC from point sources and provides some limited and indirect improvements towards excessive algal growth, taste and odor compounds, and pathogens.
When examining all dischargers, proximity is also an important factor for potential impact on a downstream water intake. According to the GIS coverages, only the Dupont Experimental Station NPDES discharge is within or near 1 mile from the Wilmington intake. The next closest NPDES discharge is 4 miles upstream from the intake at Winterthur. Five miles upstream the Greenville Country Club is the third closest NPDES. The largest concentration of major dischargers is located along or near the Route 30 corridor, including Malvern, Downingtown, and Coatesville.
Of the 92 NPDES dischargers identified in Pennsylvania a detailed breakdown by Standard Industrial Classification is provided. As shown in Table 2-40 the majority of discharger in PA (34 or 37%) is sewage system facilities.
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Table 2-40 –The Top 30 Largest NPDES Dischargers in the Brandywine Creek Watershed 1998
Subbasin Dischargers Name Type flow limit (MGD) 1994-1998 average (MGD)
West Branch Northwest Chester County STP STP 0.6 0.433
West Branch Tel Hai Rest Home STP STP 0.055 0.044
West Branch Coatesville City Authority - WTP IND 0.14 0.073
West Branch Lukens Steel no. 1 and no. 16 IND 1 0.76
West Branch Coatesville City Authority - STP STP 3.85 2.87
West Branch South Coatesville Borough STP STP 0.39 0.224
West Branch Parkesburg Borough Authority STP STP 0.7 0.263
West Branch Lincoln Crest Mobile Home Park STP STP 0.036 0.038
West Branch Embreeville Center STP STP 0.2 0.059
East Branch Indian Run Mobile Home Park STP STP 0.0375 0.037
East Branch Little Washington Wastewater Company STP STP 0.0531 0.042
East Branch Eaglepoint Development STP STP 0.015 0.001
East Branch PA Turnpike Service Plaza STP STP 0.05 0.014
East Branch Uwchlan Township Municipal Authority STP STP 0.475 0.033
East Branch Pepperidge Farm IND 0.144 0.021
East Branch Downingtown Area Regional Authority STP 7.134 5.4
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East Branch Sonoco Products IND 1.028 0.806
East Branch Broad Run Sewer Company STP STP 0.4 0.26
East Branch West Chester Borough - Taylor Run STP STP 1.8 1.27
East Branch Philadelphia Suburban Water- Ingrams Mill WTP 0.369 0.137
Main stem Radley Run Mews STP STP 0.032 0.017
Main stem Radley Run Country Club STP STP 0.017 0.008
Main stem Birmingham/TSA STP STP 0.04 0.0107
Main stem Birmingham Township STP STP 0.15 0.05
Main stem Knights Bridge/Villa at Painters STP STP 0.045 0.021
Main stem Menhenhall Inn STP STP 0.022 0.011
Main stem Unionville - Chadds Ford Elementary School STP 0.0063 0.0027
Main stem Winterthur STP STP 0.025 0.011
total (MGD) total (MGD)
18.8 12.9
Source: Keorkle and Senior, 2002
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Table 2-41 – Summary of SIC Codes for 92 NPDES Dischargers in PA
# of facilities Standard Industrial Classification
34 SEWERAGE SYSTEMS
5 GASOLINE SERVICE STATIONS
4 PRIVATE HOUSEHOLDS
3 REFINED PETROLEUM PIPELINE
3 INDUSTRIAL INORGANIC CHEMICALS
2 PHYSICAL FITNESS FACILITIES
2 UNSUPPORTED PLSTICS FILM/SHEET
2 CANNED FRUITS, VEG, PRES, JAM
2 COMMERCIAL PHYSICAL RESEARCH
2 INORGANIC PIGMENTS
2 PLSTC MAT./SYN RESINS/NV ELAST
2 GLASS CONTAINERS
2 HOTELS AND MOTELS
2 WATER SUPPLY
2 MUSEUMS AND ART GALLERIES
1 MOTOR VEHICLES & CAR BODIES
1 ALKALIES AND CHLORINE
1 ANALYTICAL INSTRUMENTS
1 ASPHALT FELT AND COATINGS
1 BLAST FURN/STEEL WORKS/ROLLING
1 BREAD & OTHER BAKERY PRODUCTS
1 BUSINESS SERVICES, NEC
1 CANNED SPECIALTIES
1 EATING PLACES
1 ELECTRICAL SERVICES
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1 ELEMENTARY & SECONDARY SCHOOLS
1 INDUST. ORGANIC CHEMICALS NEC
1 IRON AND STEEL FORGINGS
1 NATURAL GAS LIQUIDS
1 OPER OF DWELL OTHER THAN APART
1 VOCATIONAL SCHOOLS, NEC
1 PAPERBOARD MILLS
1 PETROLEUM BULK STATIONS & TERM
1 SERVICES, NEC
1 PETROLEUM REFINING
1 REFUSE SYSTEMS
1 READY-MIXED CONCRETE
1 OIL FIELD MACHINERY
2.4.1.3. Underground Storage Tanks
Underground and Aboveground Storage Tanks can store large quantities of toxic chemicals that if directly released into the Brandywine Creek would result in potential water intake closures. According to records, there are 504 tanks in Delaware and 154 in PA upstream of the Wilmington intake (total 658 tanks). The types of tanks vary significantly, but a majority in Delaware and PA are commercial or gas station related (See tables 2-42 and 2-43). Though many tanks are reported, not all tanks are active. In PA, less than half of the 504 reported tanks are in a status that may be considered active or potentially active in the future (see Table 2-44).
Of the tanks in PA, an analysis was conducted of 220 tanks with more detailed information available. Of those only 112 tanks were considered active, in use, or exempt from state law. Of those tanks approximately 78% were gas or diesel fuel tanks. The remaining 12% held a variety of chemicals (see table 2-45). The size of the tanks ranged from 100 gallons to 20,000 gallons (see table 2-46). The largest tanks reaching 15,000 to 20,000 gallons tended to be for aviation gas, fuel oil, diesel fuel, kerosene, gasoline, and jet fuel. The largest hazardous substance tank was 1,000 gallons. Hazardous substances of unknown types were stored either at Sunoco market terminal in Exton or at Scott Honda.
Tanks ranged from 4 to over 76 years old in PA (see Table 2-47). The oldest tanks were located at Zekes. Almost all of the Delaware USTs are within 5 miles of the Wilmington intake suggesting that any direct releases from these tanks would have the potential for
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immediate impacts on Wilmington’s water supply. There is a large concentration of USTs on the west side of the main stem Brandywine within 1 to 2 miles of the intake. The next largest concentration of storage tanks is located generally around 20 miles from the Wilmington intake. This is still within a close enough distance to assume that dilution will be limited and impacts would appear within a day of the accident at Wilmington’s intake depending on flow and rainfall. The information in the PADEP records for storage tanks indicates there is no last date of inspection for some of the older tanks. Therefore older tanks that have not been inspected in the past decade should be a priority for inspection.
Table 2-42 – Types of Storage Tanks in Delaware Portion of the Brandywine Creek
Major Type Number Percentage
Agricultural 1 1%
Automotive 30 21%
Commercial/Retail/Services 33 23%
Educational 3 2%
Government 11 8%
Health Care 9 6%
Industrial 4 3%
Recreation 2 1%
Religious 12 8%
Residential 39 27%
Unknown 1 1%
Total 145
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Table 2-43 – Types of Storage Tanks in Pennsylvania Portion of the Brandywine Creek
Facility Type Number Percentage
Aviation 4 1%
Agricultural 4 1%
Manufacturing/Industrial 121 24%
Gas Station 128 25%
Gas Storage 5 1%
Other 19 4%
Oil Supplier 34 7%
Government 48 10%
Retails/Commercial 64 13%
Services 1 0%
Transportation 9 2%
Unavailable 1 0%
Unknown (for stds conv only) 65 13%
Utilities/Sanitary Services 1 0%
Total 504
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Table 2-44 – Storage Tank Status in Pennsylvania Portion
Tank Type Number Percentage
Active 1 0%
Closed w/out permit 200 40%
Currently in use 109 22%
Exempt from State Law 98 19%
Permanently Closed in Place
8 2%
Removed 72 14%
Temporarily out of use 8 2%
Transferred 3 1%
Unregulated Removed 5 1%
Total 504
Table 2-45 – Types of Substances Reported in Active Storage Tanks in PA
Type Number Percent
Aviation gas 1 1%
Diesel 40 22%
Gas 102 56%
Heating Oil 8 4%
Hazardous Substance 3 2%
Jet Fuel 3 2%
Kerosene 10 5%
New Motor Oil 1 1%
Other 12 7%
U.S. Dept. Of Labor Regulated 3 2%
Total 183
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Table 2-46 – Amount of Substances Stored in Tanks in PA Upstream of Wilmington’s Intake
Parameter Minimum
tank size
(gallons)
Maximum
tank size
(gallons)
Aviation Gas 15,000 15,000
Diesel 500 20,000
Gas 550 15,000
Heating Oil 12,000 20,000
Hazardous Substances 350 1,000
Jet Fuel 15,000 15,000
Kerosene 1,000 20,000
New Motor Oil 2,000 2,000
Other 3,000 5,000
U.S. Dept. Of Labor Regulated 300 2,000
Table 2-47 – Storage Tank Ages in PA (for tanks that had ages provided)
Parameter Age (years)
min 4
max 76
average 19
Std.dev. 11.7
Count 102
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2.4.1.4. Spray Irrigation and Large On-Site Septic Systems
Spray Irrigation and Large On-Site Septic Systems represent the potential for large concentrated areas of groundwater influence from sewage. Also spray irrigation has the potential to impact surface waters from runoff. Both activities are monitored and permitted by state and federal agencies to ensure they do not impact streams. In some cases, these facilities are required or preferred by regulators instead of direct discharge to the Brandywine Creek directly. Therefore, the potential for an immediate impact from these facilities is unlikely, but long term studies and monitoring are necessary to ensure as these options are more heavily utilized instead of direct discharge that they remain effective.
According to Delaware records, there is only 1 spray irrigation system in the Delaware portion of the Brandywine Creek Watershed. There are 20 identified spray irrigation systems in Pennsylvania. There were 35 large on-site septic systems identified in the PA drainage area during the Wilmington SWAP. Another 77 potential large on-site systems were identified further upstream in PA in its Significant Water Resources GIS coverage. Only limited information is available regarding these facilities and actual size and flow rates were not provided. No stakeholder information suggested significant concerns from any specific spray irrigation or on-site septic systems.
2.4.1.5. Residential Septic Systems
A residential septic system is actually a broad category that includes traditional or modern septic
systems, cesspools, and seepage pits. The difference between these systems is significant from a
contaminant mitigation perspective. A traditional septic system utilizes a solids settling tank and
soil absorption field usually involving a piping manifold system. A cesspool is the older
technology prior to septic tanks. A cesspool is a large box that drains either through the bottom
or sides into the ground. The design and operation of cesspools leads to significantly less
treatment, higher failure, and more interaction with groundwater (University of Delaware, 2007).
It is assumed that most septic systems in Delaware have on average a 1,000 gallon capacity.
Most cesspool systems due to failures and additional tank installations can have an average 2,000
gallon capacity. Traditional or modern septic systems may provide greater nutrient and bacteria
reduction and operate longer, but still can be a potential source of contamination since both
effluents contains pathogens and nutrients in excessive amounts.
Residential septic systems have long been suspected sources of nutrients and bacteria in watershed studies nationwide (University of Delaware, 2007). A study by USGS identified unsewered residential areas as having higher loads of sediment and nutrients compared to other residential land uses Keorkle and Senior, 2002). The interaction between surface flow and groundwater contributions especially during low flow periods combined with the low nutrient removal by septic systems suggests that cumulatively septic systems may actually play some role as a more diffuse non-point source than as a direct point source discharge individually. Due to these concerns, New Castle County has restricted septic system
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placement on steep slopes. (University of Delaware, 2007)
A number of efforts have been conducted to estimate the amount of septic systems and their operational status in the watershed. The most comprehensive evaluation is summarized in the Bacteria and Sediment TMDL for the Christina Watershed and is provided below in Table 2-48 (USEPA, 2006).
An estimated 587 septic systems are located in the Delaware portion of the Brandywine Creek Watershed. DNREC estimates that all of these systems are actually cesspools with a 10.9% failure rate. In the Chester County portion of the watershed, site-specific information on the locations or numbers of septic systems was not available. However, the worst case assumption is to use the entire number of septic systems estimated for Chester County since most of Chester County drains into the Brandywine Creek Watershed. Using 2005 estimates, there were at most potentially about 55,200 septic systems in the Chester County portion of the basin. The failure rate for these systems is roughly one known failure for every two newly permitted systems. It is less than the 10.9% failure rate for Delaware’s cesspool system, but over 1%. Other failure rates for septic systems in Delaware ranged from 2.9% to 11.2%. It is assumed that the failure rate in the watershed ranges from 1 to 10.9% depending upon location.
A worst case analysis can be conducted to provide some perspective on the overall potential
impacts on septic systems. Assuming a typical household generates 10–15 pounds of nitrogen
per year and 1–2 pounds of phosphorus per year and there are 55,200 septic systems in the
Brandywine Creek, the septic systems will generate 250-376 tons of nitrogen and 15 to 50 tons of
phosphorous per year. If this is assumed to enter the creek annually it still only makes up 2 to 4%
of the total phosphorous and nitrate annual loads for the entire watershed that were estimated by
USGS in 1998. Compared to other point sources septic systems only are 10 to 15% and 1 to 2%
of the point source load from NPDES dischargers for nitrogen and phosphorus respectively. Thus
during baseflow periods septic systems are not currently the dominant point source potential
impact on intake water quality.
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Table 2-48 – Census Data for Septic System Estimates
Location
Septic System Estimate New Castle
County Chester County Source
2004 DNREC Estimate of Septic Systems in Christina River Basin 1,713 ----- USEPA, 2006
2005 Estimated Number of Septic Systems in Christina River Basin 1,650 55,200 USEPA, 2006
2005 Estimated Number of Malfunctioning Septic Systems in Christina River Basin 17 552 USEPA, 2006
2005 Estimated failure rate 1.03% 1.00%
1990 Estimated septic tanks or cesspools countywide 12,142 50,396 University of Delaware,
2007
Estimated # of Septic Systems in Delaware Portion of Brandywine Creek 587 -----
University of Delaware, 2007
Estimated failure rate for septic systems in Brandywine Creek 10.90% -----
University of Delaware, 2007
Range of failure rates for Christina basin and subbasins
2.9 - 11.2% (7.2 avg) ------
University of Delaware, 2007
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2.4.1.6. Hazardous Waste, Toxic Release Inventory, Landfills, and Contaminated Sites
There are activities, facilities, and sites in the watershed that may generate, release, store, discharge, or release toxic and hazardous substances. Most of these places are regulated or monitored under the Toxic Release Inventory (TRI), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Superfund program, or Resource Conservation and Recovery Act (RCRA). Facilities reported by the TRI system can generate or discharge toxic substances into the air, land, or water. CERCLA or Superfund is a program that monitors and cleans up the most contaminated lands that directly release or threaten to release hazardous substances. RCRA facilities are regulated the framework for the proper management of hazardous and nonhazardous solid waste including controlling hazardous waste from the time it is generated units its ultimate disposal – in effect, from "cradle to grave".
In the watershed upstream of the Wilmington intake there are 61 known facilities that are regulated under the previously mentioned programs, 2 from TRI, 3 from CERCLA, 3 Commercial hazardous waste generators in Pennsylvania, 41 hazardous waste generators in Delaware, and 12 landfills in Pennsylvania. It is important to note that being listed in these programs does not necessarily mean the facility is releasing or discharging a toxic or hazardous substance upstream from the water intake. In most situations, facilities in these programs are heavily monitored to prevent such events from occurring. In order to determine their potential for impact on the intake the permit compliance status, status of remediation, and mitigation requirements should be evaluated. At the very minimum, these are facilities that notification and communication protocols should be established between Wilmington and the facility. The following Toxic Release Inventory and Superfund facilities are located immediately upstream from the Wilmington Intake:
Toxic Release Inventory Facilities
Dupont Experimental Station
Wilmington Piece Dye
Superfund (CRCLA) Sites
Bancroft Mills
Dupont Exp. Station
Container Corp.
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2.4.1.7. Combined Sewer Overflows
A combined sewer system is a system that has both stormwater and sanitary sewage combined in one conveyance pipe instead of two separate pipes. During dry weather a combined sewer does not discharge into the local waterbody. During wet weather, the flow in the pipe can exceed the carrying capacity of the collection system and discharge via an overflow into a nearby stream or river, this is called a combined sewer overflow (CSO). The nature of the discharge is a mixture of urban stormwater runoff and sanitary sewage. Thus, it naturally has been reported to contain high concentrations of pathogens and other contaminants compared to other wet weather sources. Elimination of discharges of untreated sewage and combined sewers upstream from drinking water intakes is a major goal of most regulatory programs.
The Rockford Road CSO is located in the City of Wilmington in the Rockford Park neighborhood immediately upstream of the Wilmington intakes on the opposite side of the Brandywine Creek from the Wills intake for Porter Filter Plant and Hoopes and on the same side of the Brandywine Creek as the Brandywine Filter Plant raceway. The City of Wilmington has an initiative underway to eliminate the Rockford Road CSO by removing the stormwater from the combined system to a new separate stormwater system.
2.4.1.8. Transportation Crossings & Pipelines
There are several major highway and railroad bridge crossings immediately upstream of the intake and along major branches of the Brandywine Creek. The railroads and highways also run parallel along the main stem and branches of the Brandywine Creek on winding roads that are subject to accidents near the water. Trucks on highways can transport toxic chemicals, petroleum substances, and fertilizers. An accident in one of these sensitive locations could result in the release of anywhere from a few gallons to several thousand gallons of material into the Brandywine Creek. Railroad crossings also represent a similar concern given the wide variety of chemicals transported in large quantities across and along the creek. The I-95 bridge, Route 30, and Route 100 road crossings represent the crossings with the greatest vulnerability, while the Route 100 sections that parallel the main stem is the greatest water supply vulnerability from a truck accident. The railroad crossing near I-95 and along the Route 30 corridor and lines that run along the main stem and West Branch to Coatesville are the areas of greatest water supply vulnerability from a railroad accident.
A number of natural gas and petroleum pipelines are located running throughout the watershed. Accidental releases due to pipeline breaks represent a potential source. However, the herbicide spraying to maintain the pipeline right of ways and other maintenance or clearing activities also represent a potential source of contamination.
A full listing of all relevant point sources is provided in Appendix A.
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2.4.2. Upstream Discharges & Baseflow impacts
There were 64 known discharges with NPDES permits in the watershed as of 2003. The top 30 NPDES dischargers were provided in the previous section. The total volume discharged to the watershed in 1998 was estimated to be 5.3 billion gallons per year or 12.9 million gallons per day on average. This is different from the cumulative maximum permitted discharges of 19.23 million gallons per day.
Point sources can have some effect on the water quality in the watershed during baseflow periods. Under certain conditions NPDES discharges have been reported to make up over 15% of the flow in the Brandywine Creek (BVA, 1999). These discharges cannot be ignored since they affect the baseline water quality in the watershed during non rain event influenced period (roughly 60% of the year).
The sewage discharge in the year 2100 was projected for the watershed using a population of 213,000 persons and an average discharge of 12.9 MGD as the current status and the projected population of 384,000 persons. It was projected that the future sewage discharges in the watershed by 2100 are projected to almost double to 23.2 MGD. This suggests that during non rainfall periods that the NPDES discharges in the future could make up 30% of the baseflow especially if this increase in discharges is associated with increased withdrawals from the basin. The water quality impacts from the contaminant loads associated with the additional sewage discharges would need to be offset by increased wastewater treatment or land application if the pollutant loads to the watershed from point sources are not to increase.
A cursory review of discharge applications and dockets recently permitted by regulating agencies for the Brandywine Creek watershed suggests that nutrient load reductions are already being prescribed via additional treatment or land application for some dischargers in the watershed. However, these increased regulatory requirements may not address the issues of contaminants that appear to fall between the gaps linking CWA and SDWA. The ability of regulatory initiatives for point sources in the watershed to address emerging contaminants will need to be examined.
2.4.3. Point Source Loadings
The loads of the priority contaminant groups were estimated to determine their relative potential impact on intake concentrations at the Wilmington intake under average, maximum, and future maximum wastewater discharges. These estimates were to provide under a conservative “worst case” of the potential significance of these discharges. Table 2-49 summarizes the total annual loads of the various contaminants of concern. Table 2-50 provides a summary of the potential impacts at the Wilmington intake in relation to regulatory and operational impact thresholds as well as a comparison with the concentrations currently observed at the intake. Table 2-51 provides an estimate of the
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percentage of the regulatory threshold or observed concentrations at the Wilmington intake that could be related to NPDES discharges/point sources. These data suggest that NPDES discharges have the most potential for impact on regulatory thresholds for Cryptosporidium. The NPDES discharges also have the potential to be a significant portion of the average concentration of TOC and nitrate at the Wilmington intake. However, though the wastewater discharges may have the potential to be a significant contributor of TOC, the type and fraction of natural organic matter in the TOC is more important than the amount. For example, natural runoff with certain types of vegetation may contribute a more specific or potent natural organic matter with a higher disinfection by product potential than water with an equal or greater amount of TOC in wastewater. In the future under certain conditions, NPDES discharges could have the potential to be a significant portion of the average ammonia concentration at the Wilmington intake as well.
Table 2-49 – Annual Estimated Loads of Various Contaminants of Concern
Annual Load of Total Wastewater
Discharges at
Parameter units 19.2 MGD 23.2 MGD
Nitrate* tons/yr 638.8 1149.8
Ammonia* tons/yr 12.5 22.5
Phosphorus* tons/yr 24.3 43.7
fecal coliform** cfu/yr 5.3E+13 6.4E+13
Cryptosporidium** oocysts/yr 2.7E+11 3.2E+11
TOC** tons/yr 663.1 801.3
* load estimated by Keorkle and Senior, 2002
** load estimated using average or maximum effluent concentrations
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Table 2-50 – Intake Impacts of Wastewater Discharges
Parameter
STP Effluent Discharge
(MGD)
STP effluent concentration
used Units
Estimated intake
concentration Units
Regulatory limit /
Operational impact
threshold
average / max
observed at intake
Crypto- sporidium 12.9 1 oocysts/L 0.04 oocysts/L 0.075 0.065/0.88
Crypto- sporidium 19.2 1 oocysts/L 0.06 oocysts/L 0.075 0.065/0.88
Crypto- sporidium 23.2 1 oocysts/L 0.07 oocysts/L 0.075 0.065/0.88
fecal coliform 12.9 200 cfu/100mL 79 cfu/100mL N/A 182/2419 (E.coli)
fecal coliform 19.2 200 cfu/100mL 118 cfu/100mL N/A 182/2419 (E.coli)
fecal coliform 23.2 200 cfu/100mL 142 cfu/100mL N/A 182/2419 (E.coli)
TOC 12.9 25 mg/L 0.99 mg/L 4 / 8 2.5/7.69
TOC 19.2 25 mg/L 1.47 mg/L 4 / 8 2.5/7.69
TOC 23.2 25 mg/L 1.78 mg/L 4 / 8 2.5/7.69
Nitrate 12.9 10 mg/L 0.95 mg/L 10 2.1/3.6
Nitrate 19.2 10 mg/L 1.42 mg/L 10 2.1/3.6
Nitrate 23.2 10 mg/L 2.55 mg/L 10 2.1/3.6
Phosphorus 12.9 0.1 mg/L 0.04 mg/L N/A 0.3/2.2 (Ortho-P)
Phosphorus 19.2 0.1 mg/L 0.05 mg/L N/A 0.3/2.2 (Ortho-P)
Phosphorus 23.2 0.1 mg/L 0.10 mg/L N/A 0.3/2.2 (Ortho-P)
Ammonia 12.9 1 mg/L 0.02 mg/L 0.1 0.1/0.9
Ammonia 19.2 1 mg/L 0.03 mg/L 0.1 0.1/0.9
Ammonia 23.2 1 mg/L 0.05 mg/L 0.1 0.1/0.9
* assumes an annual flow of 505.7 cfs in the Brandywine Creek at Wilmington and 100% mixing for concentration estimates
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Table 2-51 – Estimated Potential Impact and Contribution of Point Sources to Wilmington’s Intake Concentrations for Various Contaminants
Parameter
STP Effluent Discharge
(MGD) Estimated intake
concentration % reg
threshold
% max or avg conc at
intake Note
Crypto 12.9 0.04 53% 4% reg/avg
Crypto 19.2 0.06 78% 7% reg/avg
Crypto 23.2 0.07 95% 8% reg/avg
fecal coliform 12.9 79 40% 3% reg/max
fecal coliform 19.2 118 59% 5% reg/max
fecal coliform 23.2 142 71% 6% reg/max
TOC 12.9 0.99 25% 40% reg/avg
TOC 19.2 1.47 37% 59% reg/avg
TOC 23.2 1.78 44% 71% reg/avg
Nitrate 12.9 0.40 10% 45% reg/avg
Nitrate 19.2 1.42 14% 67% reg/avg
Nitrate 23.2 2.55 26% 121% reg/avg
Phosphorus 12.9 0.00 40% 13% reg/avg
Phosphorus 19.2 0.05 54% 18% reg/avg
Phosphorus 23.2 0.10 97% 32% reg/avg
Ammonia 12.9 0.04 20% 20% reg/avg
Ammonia 19.2 0.03 28% 28% reg/avg
Ammonia 23.2 0.05 50% 50% reg/avg
color denotes potential for impact on regulatory or operational threshold or a significant factor
color denotes potential for impact on average intake concentration
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2.4.4. Non Point Sources Inventory
Nonpoint source (NPS) pollution, unlike pollution from point sources, comes from many distributed sources in the watershed. NPS pollution is caused by runoff from ground cover. As the runoff flows over the ground surfaces, it picks up and carries away natural and human-made pollutants, finally depositing them into streams and rivers. These pollutants include:
Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas;
Oil, grease, metals, and toxic chemicals from urban runoff and energy production;
Sediment from improperly managed construction sites, destabilized streambanks, crop and forest lands, and eroding streambanks;
Salt from irrigation practices and road de-icing materials
Metals from acid mine drainage from abandoned mines;
Bacteria and nutrients from livestock, pet wastes, and wildlife
Atmospheric deposition and hydromodification are also considered sources of nonpoint source pollution. An example of atmospheric deposition is from PCBs. An example of hydromodification is streambank erosion due to channelization and downcutting of streams from urban stormwater runoff.
The impacts from non-point source runoff are usually categorized into Urban/Suburban Runoff, Agricultural Runoff, and Wildlife/Forest Runoff related impacts.
2.4.4.1. Urban/Suburban Stormwater
Urban and suburban stormwater runoff can contain various metals, nutrients, pathogens, organic chemicals, and sediment. In addition to these constituents, the high flow velocities from urban runoff can actually create significant erosion of streambanks and scour significant deposits of contaminated sediments. Though some data suggests the runoff from areas with more than 40% impervious cover can result in metal levels in streams that are toxic, the most significant damage is caused by flow. Flow not only erodes the streambank and downcuts the main channel, it also scours the streambed eliminating aquatic life habitat embedding the streambed from deposits that essentially choke out the chance for life to establish and sustain in the streambed. From a drinking water perspective there is a growing amount of reports in literature that urban and suburban runoff can actually produce trace organic waste contaminants such as PBDEs and other compounds that are not easily removed by water treatment and represent a potential human health concern.
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Therefore, the prevention of stormwater runoff and management of stormwater runoff through proper treatment is the most important activity that can be undertaken.
2.4.4.2. Agriculture Activities
Agricultural lands are estimated to make up 39% of the land cover in the Brandywine Creek Watershed. Census data from the USDA in 2002 suggests that approximately one quarter of the land is croplands, one quarter is pasture, and the remaining half is undetermined. Recently the TMDL report by USEPA (USEPA, 2006) classified 84% of the agricultural land use in the Brandywine as row croplands and the remaining 16% was livestock pasture areas. The type of agricultural use and proximity to the stream is extremely important when prioritizing the mitigation of agricultural land uses. The location and concentration of animal feeding and watering activities, barnyards, and manure application can all be important in the loading of pathogens and pharmaceuticals from a particular livestock operation. The tilling or no-tilling, riparian buffers, fertilizer and manure applications for croplands can have a significant impact on the sediment, nutrients, pesticides/herbicides, and pharmaceuticals that reach the stream from cropland operations.
The inventories of livestock in Chester County and New Castle County from the last three agricultural census periods are shown in Table 2-52. As shown there are approximately 766,000 livestock in Chester and New Castle County. Assuming that the livestock is divided evenly in the counties and using the percentage of the counties that drain into the Brandywine Creek Watershed, there is potentially 580,000 livestock in the Brandywine Creek Watershed. If there are roughly 213,000 people living in the Brandywine watershed, this suggests that there are more than 2 livestock animals per person living in the watershed. Thus, the waste from a population of animals that can create more fecal material than humans creates a situation of untreated sewage/animal waste that is an order of magnitude greater than human contributions that are typically treated. It should be noted that over 90% of the livestock included poultry. Removing the poultry from the potential livestock, there are potentially 32,000 cattle, pigs, horses, sheep, and lambs in the watershed. Again, given these larger animals can produce ten times more fecal material than humans on a daily basis they would represent the same potential fecal production as 320,000 people. Most importantly this waste is not treated and in most cases spread in the watershed for fertilizer or potentially concentrated near or into streams. Other than fecal coliform bacteria there is data suggesting that neonatal livestock actually can produce pathogen levels such as Cryptosporidium at levels that are even more significant than adult livestock or humans. For example a young calf could produce the equivalent daily load of Cryptosporidium as 100 adult cows or 1,000 immunocompromised humans (Crockett, 2007).
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Table 2-52 - Livestock Inventories from 2002 USDA Agricultural Census & Estimated in the Brandywine Creek Watershed by EPA
USDA Countywide Census Data 2002 EPA Estimate for Watershed
Category Chester County New Castle County Chester County
New Castle County
Cattle and calves
41,878 2,665 5286 / 31900 * 633 / 1736 *
Hogs and Pigs
12,860 86 6,540
280
Poultry
696,361 740,480
220,308
Horses
8,597
833 5,293
737
Sheep
2,856
366 2,580
222
Total
762,552
3,950 792,079
223,916
Source: USEPA, 2006
2.4.4.3. Wildlife
Wildlife also generates bacteria on the land surfaces and in streams. Wild animals are also assumed to be the only source of bacteria on forested land. A precise estimate of the number of wild animals in the Brandywine Creek is not available. Wild animal populations were estimated based on animal densities in the EPA TMDL report (USEPA, 2006). Based on these values it is estimated there are approximately 71,715 wild animals in the watershed. Surprisingly, these estimates suggest that 60% of the wild animals are located in row crop lands and 32% are in forested lands in the watershed. The number of wild animals is roughly 10% of the estimated number of livestock in the watershed. Removing poultry from the watershed estimate, wildlife is approximately twice the number of animals estimated for cattle, horse, and pig livestock in the watershed.
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Table 2-53 – Estimated Location of Wild Animals in the Brandywine Watershed
Wild Animal
Row crop
(total # animals)
Livestock (total #
animals)
Forest (total #
animals)
total # wild
animals in watershed
Ducks 3,192 612 1,027 4,831
Geese 5,320 1,020 - 6,340
Deer - 714 3,595 4,309
Beaver 532 102 1,027 1,661
Raccoons 266 51 514 831
Other 34,048 3,264 16,432 53,744
Total 43,358 5,763 22,594 71,715
Source: USEPA, 2006
2.4.4.4. Domestic Pets
Domestic pets are potential sources of bacteria in a similar way as wildlife. Cats and dogs can contribute fecal material within the watershed that may find its way into surface waters. This source is more likely in more populated areas where large numbers of pets (and abandoned pets) tend to be found.
As reported by EPA in the TMDL report (USEPA, 2006), a national study American Pet Products Manufactures Association reported that 39.1 percent of households own at least one dog and 32.1 percent own at least one cat. The average number of dogs per dog-owning household is 1.41, and the average number for cats is 2.4 per cat-owning household. There are an estimated 149,812 households in the Christina River Basin (USEPA, 2006). Based on the APPMA national study, approximately 58,576 households own dogs and 48,090 households own cats. Using these values produces an estimate of 82,593 dogs and 115,415 cats within the Christina River Basin (see Table 2-54). Assuming the Brandywine Creek is approximately 57% of the Christina River Basin, a rough estimate of cats and dogs is 65,787 and 47,078 respectively. The total number of cats and dogs is 112,865 pets which is roughly 15% of the estimated animals in the watershed as shown in Tables 2-55 and 2-56.
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Table 2-54 – Estimated Numbers of Cats and Dogs in the Christina and Brandywine Watersheds
Pet Christina Brandywine
cats 115,415 65,787
dogs 82,593 47,078
Table 2-55 – Estimated Numbers of Animals in the Brandywine Watershed
animal type total estimated # in Brandywine Watershed
cats&dogs 112,865
wild animals 71,715
livestock 579,317
livestock w/out poultry 31,667
total # animals 763,896
total # animals w/out poultry
216,247
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Table 2-56 – Detailed Breakdown of Estimated Numbers of Animals in the Brandywine Watershed
animal category
animal Total estimated # in Brandywine
Watershed
livestock beef cattle 3,374
livestock dairy cattle 19,173
livestock swine (hogs) 3,887
livestock poultry 547,649
livestock horses 3,437
livestock sheep 1,597
livestock other ag animals
200
wild Ducks 4,831
wild Geese 6,340
wild Deer 4,309
wild Beaver 1,661
wild Raccoons 831
wild Other wild animals
53,744
pets cats 65,787
pets dogs 47,078
Total 763,896
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2.4.5. Non Point Source Loadings
The multitude of non-point sources requires a series of loading analysis aimed at identifying the priority non-point sources as they relate to impacts on the Wilmington intake. These analyses include comparisons of landuse types to identify specific types of non-point source activities to control. It also includes analysis of the animal contributions to non-point source contaminants in order to prioritize within a given landuse (ex. Agricultural), which types of animal practices are more important to mitigate/control. A final analysis is also conducted to geographically prioritize the subsheds that have the largest non-point source contributions of contaminants for focused implementation plan development at the clustered parcel and first order stream level. It also identifies key subsheds that currently have low non-point source loadings and should be examined for detailed prioritization plan activities.
2.4.5.1. Land Use Type Estimates
As shown below in Table 2-57 the priority land use type depends upon the potential contaminant concern. For example, the estimates suggest that agricultural row crop lands are the dominant source of nitrogen, phosphorus, and sediment from non-point sources in the watershed. However, from a pathogen perspective, agricultural livestock, urban and sewered residential areas are dominant sources. Residential and urban areas and agricultural row crop areas had the highest contributions of Total Organic Carbon.
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Table 2-57 – Summary of Load Portions Attributed to Different Land Use Types in the Brandywine Creek Watershed
% annual Load
Land Use/Surrogate Cryptosporidium Fecal Coliform TOC Nitrogen Phosphorous TSS
Residential-septic 10% 0% 12% 7% 6% 3%
Residential sewer 18% 33% 16% 7% 5% 3%
Urban 12% 21% 14% 4% 3% 2%
Agricultural - livestock 24% 0% 4% 4% 7% 15%
Agricultural - row crop 8% 0% 15% 62% 68% 52%
Agricultural - mushroom 0% 0% 0% 0% 0% 0%
Forested 0% 0% 9% 2% 3% 2%
Open 0% 0% 2% 2% 1% 1%
Wetland water 0% 0% 0% 0% 0% 0%
Undesignated 1% 0% 1% 2% 0% 18%
Impervious-residential 14% 24% 12% 5% 4% 2%
Impervious-urban 13% 23% 15% 5% 4% 2%
Note: Data estimated merged with data from Keorkle and Senior, 2002
2.4.5.2. Animal Non Point Source Contributions
As noted above the agricultural livestock and urban/residential land uses were considered the dominant sources of pathogens. However, it does not provide information as to which sources within those land uses are potential priorities for mitigation. Using estimated fecal production and concentrations in animal feces reported in literature (USEPA 2006, Crockett, 2007). An estimate of the relative contribution of fecal coliforms and Cryptosporidium in the watershed is available in Tables 2-58 and 2-59. Using these estimates dairy cattle and especially dairy calves are potentially the greatest contributors of pathogens to these land uses and a primary source for control. Pigs, dogs, and geese were estimated to be the other secondary major sources for control and mitigation on a subshed basis depending upon water quality measurements and available land uses. Further confirmation using DNA fingerprinting and microbial source tracking methods for bacteria and Cryptosporidium should be conducted to confirm these estimates.
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Table 2-58 – Animal Contributions of Fecal Coliform in the Brandywine Watershed
animal category
Animal Total estimated #
in Brandywine
fecal coliform production
(cfu/animal/day)
fecal coliform
production (cfu/day)
% fecal coliform
production
livestock beef cattle 3,374 1.04E+11 3.51E+14 9%
livestock dairy cattle 19,173 1.01E+11 1.94E+15 51%
livestock swine (hogs) 3,887 1.08E+10 4.20E+13 1%
livestock Poultry 547,649 1.36E+08 7.45E+13 2%
livestock Horses 3,437 4.20E+08 1.44E+12 0%
livestock Sheep 1,597 1.20E+10 1.92E+13 1%
livestock other ag animals 200 3.81E+10 7.59E+12 0%
wild Ducks 4,831 2.43E+09 1.17E+13 0%
wild Geese 6,340 4.90E+10 3.11E+14 8%
wild Deer 4,309 5.00E+08 2.15E+12 0%
wild Beaver 1,661 2.50E+08 4.15E+11 0%
wild Raccoons 831 1.25E+08 1.04E+11 0%
wild Other wild animals
53,744 1.05E+10 5.62E+14 15%
pets Cats 65,787 4.09E+09 2.69E+14 7%
pets Dogs 47,078 4.09E+09 1.93E+14 5%
Total 763,896 3.78E+15
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Table 2-59 – Animal Contributions of Cryptosporidium in the Brandywine Watershed
Animal category
Animal Total estimated # animals in Watershed
median oocysts/ day total
% of total
median
max oocysts/ day total
% of total max
livestock beef cattle 3,374 2.0E+07 0% 2.0E+07 0%
livestock beef calves 337 2.0E+08 0% 2.0E+08 0%
livestock dairy cattle 19,173 7.7E+07 0% 7.7E+07 0%
livestock dairy calves 1,917 5.8E+12 98% 5.8E+12 95%
livestock swine (hogs) 3,887 7.3E+09 0% 1.2E+11 2%
livestock poultry 547,649 0.0E+00 0% 0.0E+00 0%
livestock horses 3,437 3.1E+08 0% 3.1E+08 0%
livestock sheep 1,597 3.7E+07 0% 1.5E+10 0%
livestock other ag animals 200 0.0E+00 0% 0.0E+00 0%
wild Ducks 4,831 3.5E+07 0% 1.6E+09 0%
wild Geese 6,340 4.5E+09 0.1% 7.8E+09 0.1%
wild Deer 4,309 9.8E+06 0% 9.8E+06 0%
wild Beaver 1,661 1.9E+05 0% 1.9E+05 0%
wild Raccoons 831 5.1E+06 0% 8.4E+06 0%
wild Other wild animals
53,744 6.1E+06 0% 6.1E+06 0%
pets cats 65,787 1.3E+08 0% 1.3E+08 0%
pets dogs 47,078 1.3E+11 2% 1.3E+11 2%
Total 766,151 5.90E+12 6.03E+12
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2.4.5.3. Subwatershed Loading Comparisons
An analysis was conducted to estimate the loading of various contaminants by subwatershed in order to provide a relative basis from which to assign geographical priorities for various contaminants of concern to Wilmington’s water intake. The USEPA TMDL and USGS HSPF study (USEPA, 2004 and Keorkle and Senior, 2002) provided the basis for the subwatershed land uses. Loadings were estimated for phosphorus, nitrogen, and sediment by multiplying the event mean concentrations provided in the TMDL and USGS documents (lbs/acre/yr) times the acres of the various landuses for the appropriate segments as provided by the USGS. Loadings for TOC, fecal coliform, and Cryptosporidium were calculated by multiplying event mean concentrations for each land use subtype times the land use subtype for each reach and summing them together for a total load for the reach. Loads were calculated annually on a total load for each subwatershed. Loads were also calculated to determine a per square mile total annual load for each subwatershed since all of the subwatersheds are different sizes and thus would lead to potential improper comparison.
As shown in Table 2-60, the greatest loadings typically came from throughout the West Branch of the Brandywine Creek and its tributaries mainly due to agricultural land use with some focus in the Coatesville area. The West Branch and its tributaries were high for all contaminant categories including nutrients, sediment, pathogens, and TOC. Only the sections of the East Branch including Downingtown, Exton, and West Chester appeared as areas with high potential loadings for TOC, fecal coliforms, and Cryptosporidium.
The West Branch of the Brandywine Creek at Honey Brook was estimated to produce the greatest loads of sediment and Cryptosporidium. The West Branch of the Brandywine Creek in the Coatesville area was identified as having high loads of TOC, fecal coliforms, and Cryptosporidium. The West Branch of the Brandywine Creek in the Pocopson Township area was identified as having high potential phosphorous loadings. Significant tributaries to the West Branch such as Buck Run and Doe Run were identified as areas with high nutrients and sediment loading.
The East Branch of the Brandywine Creek at Downingtown was identified as an area of high loadings for TOC, fecal coliform, and Cryptosporidium. The tributaries to the East Branch at Taylor Run in the West Chester, West Goshen, and E. Bradford townships were identified as high loading areas for fecal coliform only. Valley Creek in the Exton area of the watershed including West Whiteland and East Bradford townships was another high loading area for pathogens and TOC. Beaver Creek in East and West Brandywine and Caln townships had high loadings for TOC and fecal coliforms.
In the Lower Brandywine Creek, the main stem area draining New Castle County just outside of Wilmington on the east side of the main stem Brandywine was identified for high TOC and pathogen loadings as well.
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Table 2-60 - Priority Subwatersheds of Greatest Relative Annual Loads of Various Contaminants in the Brandywine Watershed
Subbasin name Shed TP N TSS TOC Fecal Crypto
West Branch Brandywine Creek 1 X
West Branch Brandywine Creek 5 X X X
West Branch Brandywine Creek 8 X
East Branch Brandywine Creek 12 X X X
East Branch Brandywine Creek/Taylor Run 14
Upper & Lower Buck Run 20 X
Upper Doe Run 21 X X X
Lower Doe Run 22 X X X
Trib to Valley Creek 28 X X
Valley Creek 29 X
Beaver Creek 30
Lower Main stem Brandywine 34 X X X X
shaded are high by total annual load
As shown in Table 2-61, the lowest loadings came from throughout the watershed usually focused in areas of low human population. However, these areas may coincide with areas of high loadings due to agricultural activity and suggest potential synergy areas for restoration and preservation work to be combined. In fact, three “synergy” areas were identified; these include Doe Run, Buck Run, and the West Branch of the Brandywine Creek in the Pocopson Township area.
The typical areas were identified as areas for continued preservation including the Chadds Ford township area, headwaters of the Upper Marsh Creek/Struble Lake Area, headwaters of the Upper Marsh Creek/Marsh Creek Reservoir Area, and West Caln township/Hibernia Reservoir Area. The majority of lowest loadings were for pathogens and TOC. However,
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generally low loadings are observed across all contaminant categories in these areas.
Tributaries such as Pocopson Creek, Birch Run, and Indian Run were also identified as potential preservation areas for low pathogen and TOC loadings. Broad Run, Birch Run, and Marsh Creek/Lyons Run were identified for preservation for low nutrients and TSS loadings.
The low nutrients and TSS loadings for some areas was due to the fact that they are heavily urbanized and would appear to have a low load as an artifact of the calculation method. However, these urban areas are not viable land preservation areas.
Overall, preservation of headwater areas in Honey Brook, West Nantmeal, East Nantmeal, Wallace, West Caln, and Upper Uwchlan appear to be the best areas for focused clustered parcel preservation of forested and open lands of first and second order tributaries.
Preservation of agricultural lands in Honey Brook, Highland, Sadsbury, Londonderry, W. Marlborough and E. Fallowfield townships appear to be the best areas for focused clustered farm parcel preservation of first and second order tributaries.
The Lower East and West Branches at East and West Bradford and Newlin townships are potential preservation areas. Main stem preservation areas should continue to be focused on the Chadds Ford, Pocopson and Pennsbury areas.
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Table 2-61- Priority Subwatersheds of Lowest Relative Annual Loads of Various Contaminants in the Brandywine Watershed
Subbasin name Shed TP N TSS TOC Fecal Crypto
West Branch Brandywine Creek 4 X X X
West Branch Brandywine Creek 7 X
West Branch Brandywine Creek 8 X X X
East Branch Brandywine Creek 9 X X
East Branch Brandywine Creek/Indian Run 10 X
East Branch Brandywine Creek 12
Brandywine Creek 17 X
Beaver Creek-2 18 X
Upper Doe Run 21 X X
Lower Doe Run 22 X X
Lower Buck Run 23 X X
Trib to Broad Run-2 24 X X
Broad Run-2 25
Marsh Creek/Lyons Run 26 X
Pocopson Creek 31 X
Birch Run 32 X X X
Upper Marsh Creek 35 X X
shaded are low by total annual load
Note: loads were examined as % avg. load by square mile
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2.4.6. Comparison of Point & Non Point Source Loadings
Point sources represent a potential source of contamination that has the opportunity to be addressed and controlled through various mechanisms by the City of Wilmington. It is also important to put the contribution of point sources for contaminants in perspective to non point sources so their importance can be examined. The best example of an available comparison was conducted by USGS for the Brandywine Creek TMDL. As shown in Table 2-62, non-point sources of nutrients, especially phosphorus, make up the majority of most nutrient contaminant loads. In Table 2-63, the annual estimated loads using alternative calculation methods suggest that in general non point sources are the dominant source of all contaminants that impact the Wilmington intake.
Table 2-62 - Summary of Contaminant Loads Estimated by USGS 1994 – 1998 (tons)
Nitrate Ammonia Phosphorus
Nonpoint 6,050 139 1,574
Point 2,555 50 97
Total 8605 189 1671
2000 Estimate of total load proportion between point and non point sources
Nonpoint 70% 74% 94%
Point 30% 26% 6%
2100 Estimate of total load proportion with point source increase from 12.9 to 23.2 mgd and no change in nonpoint load
Nonpoint 57% 61% 90%
Point 43% 39% 10%
Source: Keorkle and Senior, 2002
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Table 2-63 - Comparison of Annual Loads from Point and Non-Point Sources
Source Phosphorus Nitrogen TSS TOC
fecal
coliform Cryptosporidium
Non-point 88% 61% 100% 79% 100% 78%
Point Source* 12% 39% 0% 21% 0% 22%
Point Source
2020** 20% 53% 0% 24% 0% 26%
* is conservative estimate using 19.2 MGD (all NPDES dischargers at permit limit)
* is conservative estimate for growth in 2020 using 23.2 MGD (all NPDES dischargers at permit limit)
Though some data suggests that point sources may not appear to be the dominant sources of certain types of pollution in the watershed, they may still be important potential sources of contamination and could impact water intake quality under specific conditions. When it is not raining, some non-point source originating pollutants are not present and point sources are the only source of a particular contaminant. Cryptosporidium, pharmaceuticals, and organic waste contaminants are good examples of these situations. For example, a Cryptosporidium outbreak such as the one in the summer/fall of 2007 represented the conditions where a large loading of Cryptosporidium in the watershed had the potential to impact water quality at the intakes downstream. Another example is the case of a malfunction or treatment failure at an upstream discharger. This may result in large quantities of raw sewage discharged to the stream. Toxic spills and industrial discharges can also cause impacts on wastewater discharges that may need to be considered.
Though the previous examples represented acute situations, chronic events can happen that impact downstream water quality. For example, a discharger can have a discharge of a chemical or compound at trace levels that is sporadic and difficult to detect or trace. An example of these types of events in the Brandywine would be the discharge of a taste and odor compound such as trichloroanesol or a compound that once it enters the stream can be converted to a form that represents a water quality impact.
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3. Section 3 - Prioritization of Potential Sources and Identification of Restoration & Protection Projects
3.1. Priority Issues in the Watershed
Based on the water quality analysis and technical data presented in Section 2, the priority contaminant groups in the watershed that impact water quality and water supply for the City of Wilmington were ranked in the following order:
Cryptosporidium & pathogens
Turbidity
Disinfection by product pre-cursors (surrogate: Total Organic Carbon)
Sodium & chloride
Algae/ Nutrients
Trace Organics
Baseflow (though flow is not a regulated contaminant it affects dilution of contaminants)
The priority sources of these contaminants are a wide varying range of activities. Within each major source type a priority issue is identified by contaminant group in Table 3-1.
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Table 3-1 – Contaminant Sources and Priority Issues
Contaminant Source Priority issue Contaminants Addressed
Agriculture Dairy Farms, cows in stream, manure management
Cryptosporidium, pathogens, nutrients, turbidity,
disinfection by products, trace organics (antibiotics)
Wastewater Raw and untreated sewage discharges, outbreaks
Cryptosporidium, pathogens, trace organics, baseflow
Urban/Suburban Runoff Road Runoff, Streambank erosion
Turbidity, sodium & chloride, baseflow
Riparian buffer removal Streambank erosion Disinfection by products, turbidity
3.2. Prioritization Methodology
The prioritization of sources was divided into a number of separate elements because the priority of a source depends upon many factors including the potential vulnerability, susceptibility, and possibility of a potential source to impact the water supply. Some sources have impacts that are continuous with chronic impacts and take a long time to lead to a threshold change in water quality. Meanwhile, some sources only have impacts during very infrequent and unlikely events but lead to immediate, acute impacts that could cause the closure of the water intake or treatment changes.
These situations are further complicated by wet and dry weather conditions. There are also the water quality impacts during dry weather periods which are almost 300 days per year while during wet weather periods dry weather sources do not have a dominant influence. As discussed in section 2, over 2/3 of all the different annual contaminant loads were due to non-point or wet weather sources. However, their impact on water treatment may be limited compared to things that impact water quality during dry weather. (It is understood that wet weather runoff can result in dry weather water quality impacts after a storm and sediment has settled).
Given these situations choosing an overall “top” priority source depends on the perspective of time and weather conditions. Most water quality managers will choose to give the immediate impacts the greatest priority, while some will give the source with greatest potential impact the greatest priority. These choices are both right given the various perspectives and needs of the water utility at a given time and the resources involved.
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However, it is still necessary to prioritize these sources in some logical fashion to determine which actions are necessary in the short and long term to mitigate future impacts on water quality.
A number of prioritizations were conducted to provide priority lists based on the situation, condition, and time perspective. The point sources prioritization approach assumes only dry weather water quality impacts on a routine daily continuous basis and based on low likelihood accidental spill impacts. Point source prioritization was then based upon the distance from the intake, the discharge flow or amount stored at a given facility. Individual contaminant ranking was not necessary since there is no way to choose which contaminant (microbial, toxics, or organics) is more important since the water treatment process is equally vulnerable to specific elements of these general classes. The way these prioritizations should be used is so that emergency planning and response communications can be prioritized and mitigated using the low likelihood high impact rankings and so long term source water protection issues can be addressed via the constant daily discharge rankings. Higher ranked NPDES dischargers may need to be considered for long term support for upgrades to tertiary treatment or ultraviolet light disinfection for protection of Wilmington’s intake against pathogens.
Non-point sources tend to be long term chronic sources, though they can have acute impacts during severe or unique wet weather periods. Non-point sources were prioritized based on the overall load contribution and loading per square mile. A distance factor was not included since during a storm event most pollutants can reach the Wilmington intake between a few hours to less than a day thus a relatively immediate impact. A cross contaminant group ranking was then determined using weighting factors based on the priority a given contaminant group is to the Wilmington intake. This information was then used to identify priority cluster areas for mitigation of non-point sources for agricultural runoff. This information was also used to help prioritize forested areas for preservation. Sub-priority areas were based on field investigations and other information provided by stakeholders and local studies.
This same approach coupled with landuse and riparian buffer characteristics was used to determine the lowest impact areas and identify sub priority areas of high priority for preservation. This allowed the non-point source impacts can be broken into the urban/suburban stormwater runoff, agricultural mitigation, or forest preservation priorities. The priority clusters for agriculture and preservation (forested) areas were identified in the most detail. However urban/suburban stormwater impacts are the most costly and difficult to address and mitigate. Therefore, this plan acknowledges that for urban/suburban areas the current MS4, TMDL, and stormwater ordinances are the frameworks for addressing these areas and any prioritization of urban/suburban stormwater influence is addressed via this framework and therefore prioritization of these areas has already been conducted by regulatory agencies.
All priority areas and issues were compared to the findings of previous planning efforts and reports. This provided some relative check to identify any differences with previous efforts by stakeholders and how the SWP Plan builds on those efforts.
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3.3. Prioritization Results – Point Sources
Starting with over 600 point sources upstream from Wilmington’s intake a final list of 344 active facilities was identified for priority ranking. The classes of priority were broken into High, Medium-High, Medium, and Low. Figure 3-1 shows the breakdown of the classes based on the overall point source score to show where the dividing lines were set between classes based on statistical breakpoints. A total of 37 facilities were determined to be of “High” priority for emergency response planning and source water protection activities. Another 34, 78, and 194 facilities were determined to be considered “Medium-High”, “Medium”, and “Low” priority respectively. Of the “High” ranked facilities, only three sites were a Superfund, TRI, or Hazardous Waste Generation sites. Over half of the “High” ranked facilities were storage tanks and the other half were NPDES dischargers. Other “High” ranked point sources in the table include a Combined Sewer Overflow outfall and locations of potential vulnerability to transportation accidents. Table 3-2 lists the recommended emergency response preparation activities to be conducted by the Wilmington SWP staff for the various priority levels. The High ranked transportation accident areas require special activity not listed in Table 3-2 which includes meeting with emergency response agencies responsible for spill and accident notification, response, and cleanup in the vulnerable areas and establishing communication protocols. Figure 3-2 identifies the location of the High ranked facilities and Table 3-3 provides the listings for the High and Medium High ranked facilities upstream of Wilmington’s intake.
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Figure 3-1 – Priority Point Source Ranking Characterization of Scores and Classification
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Table 3-2 – Priority Point Source Recommended Emergency Response Preparation Activities
Point Source Priority
Visit Frequency
Update contact
information
Locational / Monitoring Information
Water Quality Impact Preparation
High Once per year Check bi-annually
Identify outfalls, detailed location
maps, locate sampling points
Conduct estimates of water quality impacts from releases under
various extreme scenarios (loss of treatment, full release), estimate and verify time of travel,
monitor disease rates
Medium High Every 2 years Annually
Identify outfalls, detailed location
maps, locate sampling points
Conduct estimates of water quality impacts from releases under
various extreme scenarios (loss of treatment, full release), estimate and verify time of travel,
monitor disease rates
Medium Every 3 years Every 3
years Identify outfalls
only
Conduct estimates using a predetermined worst case
screening accident scenario, refine distance estimates, develop low flow and high flow TOT
estimates
Low Every permit
cycle Every
permit cycle Identify outfalls
only
Conduct estimates using worst case screening
scenario, refine estimates, develop low flow & high
flow TOT estimates
Note: High priority transportation accidents will require a separate activity related to emergency response education, communication, and preparation from that provided in the table above.
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Figure 3-2 – Location of High Ranked Point Sources Upstream of the Wilmington Intake
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Table 3-3 – Top Priority Point Sources Upstream of the Wilmington Intake
NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
COW-0001 City of Wilmington Rockford
Road CSO
Combined
Sewer Overflow
CSO NA < 1 NA High
COW-0002 Tanker Truck Accidents from I-
95, Route 100 and 30
Transportation
Accident
None NA < 1 - 10 NA Petroleum/
Toxics
High
COW-0003 Railroad Accidents from bridge
crossing and along main stem
Brandywine roads
Transportation
Accident
None NA < 1 - 10 NA Petroleum/
Toxics
High
COW-0004 Accidents from Pipeline
Crossings on the Brandywine
Transportation
Accident
None NA > 20 NA Petroleum/
Toxics
High
PA0026531 Downingtown Area Regional
Authority
PCS/NPDES ATP2 7.134 20.1 9.63 High
PA0026859 Coatesville City Authority PCS/NPDES ATP1 3.85 27.5 6.16 High
6437 Dupont Experimental Station SFUND & TRI 5.60 High
7107 Ei Dupont Experimental Station HW_Gen & TRI 4.64 High
PA0026018 West Chester Borough
Mua/Taylor Run
PCS/NPDES MUN 1.8 15.1 4.42 High
569614 Zekes Hc Sheeler AST 20000 Heating Oil 3.95 High
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NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
508704 Reilly & Sons AST 20000 Heating Oil 3.86 High
508704 Reilly & Sons AST 20000 Diesel Fuel 3.86 High
569614 Zekes Hc Sheeler AST 12000 Heating Oil 3.63 High
569614 Zekes Hc Sheeler AST 8000 Kerosene 3.47 High
569614 Zekes Hc Sheeler AST 20000 Heating Oil 3.37 High
517410 Jc Hayes AST 20000 Heating Oil 3.33 High
517410 Jc Hayes AST 20000 Kerosene 3.33 High
4161 Brandywine Raceway Assoc
Inc
UST 3.05 High
4400 Hagley Museum & Library UST 3.05 High
593737 Petrocon AST 4000 Kerosene 3.05 High
DE0021768 Winterthur Museum PCS/NPDES STP 0.025 0.0 3.03 High
PA0043982 Broad Run Sewer Co. PCS/NPDES ATP2 0.4 18.2 2.94 High
PA0053449 Birmingham Twp. Stp PCS/NPDES STP 0.15 8.9 2.93 High
6644 Bancroft Mills SFUND 2.92 High
593737 Petrocon AST 550 Gas 2.91 High
PA0054917 Uwchlan Twp. Municipal PCS/NPDES STP 0.475 23.3 2.89 High
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NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
Authority
PA0055476 Birmingham TSA/Ridings At
Chadds Ford
PCS/NPDES STP 0.04 6.4 2.88 High
511023 Texaco 100250 UST 12000 Gas 2.87 High
PA0024473 Parkersburg Borough Authority
Wwtp
PCS/NPDES STP 0.7 33.5 2.86 High
PA0055484 Keating, Herbert & Elizabeth PCS/NPDES SRD 0.0005 6.4 2.84 High
PA0055085 Winslow, Nancy PCS/NPDES SRD 0.0005 6.4 2.84 High
PA0030848 Unionville - Chadds Ford Elem.
School
PCS/NPDES STP 0.0063 7.0 2.83 High
PA0057011 Thornbury Twp./Bridlewood
Farms Stp
PCS/NPDES STP 0.0773 10.2 2.82 High
1542 Chester Cnty Airport AST 15000 Aviation
Gas
2.82 High
1542 Chester Cnty Airport AST 15000 Jet Fuel 2.82 High
4830 Carpenter Estates UST 2.82 High
3682 Dupont Winterthur Museum UST 2.82 High
5086 Estate Of Neil H Keough J UST 2.82 High
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NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
5040 Lanphear Property Albert UST 2.82 High
4838 St Joseph On The Brandywine UST 2.82 High
4198 Wilmington Country Club UST 2.82 High
PA0036200 Radley Run Mews PCS/NPDES STP 0.032 8.9 2.81 Medium
High
PA0031097 Radley Run C. C. PCS/NPDES STP 0.017 8.9 2.79 Medium
High
511023 Texaco 100250 UST 10000 Diesel Fuel 2.79 Medium
High
511023 Texaco 100250 UST 10000 Gas 2.79 Medium
High
569163 Longwood Gardens AST 6000 Diesel Fuel 2.76 Medium
High
PA0056120 Schindler PCS/NPDES SRD 0.0005 9.5 2.76 Medium
High
4986 A Felix Dupont UST 2.74 Medium
High
4666 Alapoccas Maintenance Base UST 2.74 Medium
High
4374 Alexis I Dupont Middle School UST 2.74 Medium
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NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
High
4674 Bayard Sharp Estate UST 2.74 Medium
High
3604 Brandywine Commons UST 2.74 Medium
High
3838 Concord Pike Gulf UST 2.74 Medium
High
4744 Craven Property UST 2.74 Medium
High
3611 Dupont Experimental Station UST 2.74 Medium
High
4865 Hank Blacks Foreign Car UST 2.74 Medium
High
5076 Henry Property John UST 2.74 Medium
High
6089 Laird Property UST 2.74 Medium
High
4280 Lincoln Towers UST 2.74 Medium
High
5077 Norwood Property UST 2.74 Medium
High
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NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
4114 Porter Filter Plant UST 2.74 Medium
High
6229 Reed Property UST 2.74 Medium
High
4557 Ross Holden UST 2.74 Medium
High
6135 Stonesgate Retirement
Community
UST 2.74 Medium
High
6105 Thornton Property UST 2.74 Medium
High
4620 Widener University UST 2.74 Medium
High
4386 Wilmington Piece Dye
Company
UST 2.74 Medium
High
4878 Woodlawn Trustees Inc UST 2.74 Medium
High
PA0056171 Mcglaughlin, Jeffrey PCS/NPDES SRD 0.0005 10.8 2.73 Medium
High
PA0036897 South Coatesville Borough PCS/NPDES ATP1 0.39 26.9 2.72 Medium
High
511023 Texaco 100250 UST 8000 Gas 2.71 Medium
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NPDES NPDES NPDES UST UST
MASTER ID Site Name SITE TYPE NPDES
type
Flow
(MGD)
Intake Distance
(miles)
Capacity
(gallons)
Substance
Stored
Overall
score
Rank
High
515503 Thorndale Exxon UST 10000 Gas 2.71 Medium
High
573143 Sunoco 0013 6804 UST 8000 Gas 2.70 Medium
High
569511 Sunoco 0318 3209 UST 12000 Gas 2.69 Medium
High
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3.4. Priority Non-Point Source Areas – Subwatershed Rankings
Loading Scores were calculated using the following equation which incorporated the relative magnitude of the load per square mile for a given subwatershed, the overall load contribution to the entire watershed, and the percentage of the subwatershed that is forested. As a watershed is more forested and its loadings are smaller in the overall watershed loading and compared to the average subwatershed it received a lower ranking.
The individual contaminant load score was calculated using the following formula:
(1-% forested) X ratio of contaminant load per square mile for subshed/average contaminant load per square mile for all subsheds X % of total watershed load for contaminant
The overall contaminant load score was calculated into loading scores, the average loading score and the weighted loading score. The average loading score is just the average of all the contaminant load scores to provide an overall gage of the total contaminant loading from a given subwatershed. The weighted loading score is a weighted average calculated based on the priority of the contaminant group as described earlier in this section. The weightings given to the various individual contaminants are as are provided in Table 3-4.
Table 3-4 – Weightings for Contaminant Groups for Overall Rankings
Total
Phosphorus Nitrogen
Total
Suspended
Solids
Total
Organic
Carbon
Fecal
coliform Cryptosporidium
0.15 0.15 0.05 0.25 0.05 0.35
Table 3-5 below provide a summary of the ten watersheds with the greatest weighted loading score and their land use attributes/characteristics. As expected, the subwatersheds with the greatest loading scores tended to have either the highest amount of urban/residential or agricultural lands in the watershed. Figure 3-3 shows their location in the watershed.
Table 3-6 provides the individual, average, and weighted contaminant loading scores for all 35 subwatersheds in the Brandywine Creek Watershed.
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Table 3-5 – Top Ten Areas with Greatest Overall Combined Weighted Pollutant Loadings in the Brandywine Watershed
Reach # Stream Name weighted avg score
% Agricultural
- Pasture Hay
% Agricultural - Row Crops
% Ag land total
% forested
Urban / Residential
total
Impervious total
34 Lower Brandywine Creek 0.612334 0% 2% 2% 14% 62% 29%
29 Valley Creek 0.592378 0% 21% 21% 35% 33% 13%
30 Beaver Creek 0.516642 0% 32% 32% 30% 33% 9%
20 Upper Buck Run 0.323445 6% 53% 59% 25% 13% 3%
28 Trib. To Valley Creek 0.210492 0% 3% 3% 21% 67% 23%
14 Brandywine Creek East Br. 0.203494 0% 32% 32% 30% 32% 9%
19 Brandywine Creek 0.199628 0% 4% 4% 17% 34% 9%
27 Marsh Creek 0.186072 9% 21% 29% 34% 26% 3%
33 Rock Run 0.169321 4% 38% 42% 30% 21% 4%
15 Brandywine Creek 0.165557 0% 41% 41% 17% 34% 7%
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Table 3-6 – Individual, Average, and Weighted Pollutant Loading Scores in the Brandywine Watershed
Reach # Stream Name % forested
TP score
Nitrogen score
TSS score
TOC score
Fecal score
Crypto score
Average score
weighted avg
score
34 Lower Brandywine Creek 14% 0.018 0.031 0.077 0.231 0.210 1.523 0.348 0.612334
29 Valley Creek 35% 0.034 0.041 0.056 0.122 0.124 1.548 0.321 0.592378
30 Beaver Creek 30% 0.046 0.051 0.055 0.078 0.074 1.360 0.277 0.516642
20 Upper Buck Run 25% 0.096 0.091 0.046 0.017 0.018 0.823 0.182 0.323445
28 Trib. To Valley Creek 21% 0.008 0.009 0.017 0.084 0.099 0.518 0.122 0.210492
14 Brandywine Creek East Br. 30% 0.034 0.031 0.034 0.065 0.066 0.493 0.120 0.203494
19 Brandywine Creek 17% 0.011 0.019 0.029 0.051 0.049 0.510 0.111 0.199628
27 Marsh Creek 34% 0.013 0.015 0.013 0.005 0.007 0.513 0.094 0.186072
33 Rock Run 30% 0.020 0.017 0.012 0.009 0.010 0.458 0.088 0.169321
15 Brandywine Creek 17% 0.040 0.034 0.028 0.035 0.035 0.407 0.097 0.165557
22 Lower Doe Run 18% 0.066 0.060 0.020 0.002 0.002 0.356 0.084 0.145226
31 Pocopson Creek 22% 0.032 0.026 0.014 0.005 0.004 0.364 0.074 0.138237
21 Upper Doe Run 17% 0.064 0.059 0.019 0.001 0.002 0.332 0.079 0.135781
9 Upper Brandywine Creek East Br. 33% 0.024 0.031 0.019 0.003 0.007 0.350 0.072 0.132808
35 Upper Marsh Creek 34% 0.011 0.011 0.006 0.001 0.002 0.312 0.057 0.113301
16 Brandywine Creek 39% 0.018 0.015 0.014 0.013 0.010 0.279 0.058 0.107207
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Reach # Stream Name % forested
TP score
Nitrogen score
TSS score
TOC score
Fecal score
Crypto score
Average score
weighted avg
score
18 Brandywine Creek 38% 0.011 0.021 0.021 0.012 0.011 0.252 0.055 0.097674
25 Broad Run 30% 0.016 0.013 0.010 0.010 0.009 0.247 0.051 0.094048
5 Brandywine Creek West Br. 35% 0.018 0.019 0.032 0.095 0.093 0.158 0.069 0.090974
13 Brandywine Creek East Br. 48% 0.007 0.009 0.014 0.031 0.030 0.205 0.049 0.084071
32 Birch Run 53% 0.003 0.003 0.003 0.001 0.001 0.194 0.034 0.069324
10 Brandywine Creek East Br. 40% 0.029 0.024 0.016 0.008 0.006 0.158 0.040 0.066394
12 Brandywine Creek East Br. 39% 0.006 0.005 0.008 0.034 0.037 0.152 0.040 0.065486
11 Brandywine Creek East Br. 36% 0.014 0.012 0.012 0.023 0.023 0.153 0.039 0.064974
1 Upper Brandywine Creek West Br. 20% 0.043 0.070 0.049 0.009 0.028 0.092 0.049 0.055263
7 Brandywine Creek West Br. 38% 0.032 0.026 0.012 0.004 0.003 0.064 0.023 0.032711
17 Brandywine Creek 49% 0.007 0.006 0.004 0.002 0.002 0.082 0.017 0.031411
6 Brandywine Creek West Br. 35% 0.015 0.013 0.009 0.005 0.005 0.064 0.019 0.028649
24 Trib. To Broad Run 8% 0.001 0.001 0.001 0.003 0.003 0.057 0.011 0.02119
26 Marsh Creek 60% 0.001 0.001 0.001 0.001 0.001 0.053 0.010 0.01926
3 Brandywine Creek West Br. 40% 0.008 0.007 0.006 0.004 0.004 0.030 0.010 0.014264
8 Brandywine Creek West Br. 25% 0.016 0.013 0.005 0.001 0.001 0.024 0.010 0.012931
2 Brandywine Creek West Br. 46% 0.006 0.006 0.006 0.004 0.005 0.021 0.008 0.011008
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Reach # Stream Name % forested
TP score
Nitrogen score
TSS score
TOC score
Fecal score
Crypto score
Average score
weighted avg
score
23 Lower Buck Run 49% 0.003 0.003 0.001 0.000 0.000 0.022 0.005 0.008468
4 Brandywine Creek West Br. 69% 0.000 0.000 0.000 0.001 0.001 0.002 0.001 0.001058
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Figure 3-3 – Top Contaminant Loading Score Areas in the Brandywine Creek
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3.4.1. Priority Non-Point Sources –Priority Cluster Areas for Agricultural Mitigation
The priority cluster areas for agriculture were identified based on an analysis conducted of the potential Cryptosporidium loadings of livestock in the watershed (see Tables 3-7 and Figure 3-4). Cryptosporidium is the most important contaminant group of all the contaminant groups with turbidity being a second priority. Using the livestock and wildlife estimates provided in the USEPA Bacteria TMDL, an analysis was conducted that estimated the livestock loadings based on animal type (see Tables 3-8 and 3-9). From this analysis, it was determined that the most important animals in terms of Cryptosporidium loadings into the watershed were dairy calves and cows. Based on interviews and communication with the Chester County Conservation District it was determined that the highest concentration of dairy farms were in the Honey Brook township area of the West Branch of the watershed. A windshield survey of the Honey Brook farming areas was conducted with the Chester County Conservation district to confirm and prioritize dairy farming areas based on dairy cows in the stream as the highest priority. Areas where cows were observed in the stream or known to be in the stream were estimated and a series of farm parcel clusters along tributaries and the West Branch of the Brandywine Creek was identified for future mitigation. These were broken into four different clusters with clusters 1 and 3 given the greatest priority based on cows in the stream and potential cooperation/synergy with existing stakeholder efforts (See Figure 3-5). Information regarding the cost estimates is provided in section 7.4. Clusters 2 and 4 were given second priority for implementation after clusters 1 and 3 are completed. These findings complement the recommendations of the CCCD and the Christina Basin partnership and the TWIG grant. Those studies suggested Honey Brook Township, Buck Run, and Doe Run as the highest priorities for agricultural mitigation. These findings identify a strong synergy between the stakeholders in the watershed priorities and the priorities for protection of Wilmington’s water supply.
Mitigation of cows in the stream near the Wilmington intake is also a priority, but cannot be specified at the cluster level using the prioritization approach. Thus, any cows in the stream near the Wilmington intake in New Castle County and near the main stem including its tributaries such as the Pocopson Creek should be evaluated and prioritized for cluster areas similar to the Honey Brook analysis. An analysis is currently being conducted by the Brandywine Conservancy that will prioritize these agricultural areas where livestock are in the stream in New Castle County.
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Table 3-7 – Brandywine Subwatersheds Ranked by Cryptosporidium Loading
Reach # Stream Name Crypto score
% Agricultural
- Pasture Hay
% Agricultural - Row Crops
% Agricultural
land total
% forested
29 Valley Creek 1.548 0% 21% 21% 35%
34 Lower Brandywine Creek 1.523 0% 2% 2% 14%
30 Beaver Creek 1.360 0% 32% 32% 30%
20 Upper Buck Run 0.823 6% 53% 59% 25%
28 Trib. To Valley Creek 0.518 0% 3% 3% 21%
27 Marsh Creek 0.513 9% 21% 29% 34%
19 Brandywine Creek 0.510 0% 4% 4% 17%
14 Brandywine Creek East Br. 0.493 0% 32% 32% 30%
33 Rock Run 0.458 4% 38% 42% 30%
15 Brandywine Creek 0.407 0% 41% 41% 17%
31 Pocopson Creek 0.364 0% 49% 49% 22%
22 Lower Doe Run 0.356 8% 71% 79% 18%
9 Upper Brandywine Creek East Br.
0.350 27% 27% 54% 33%
21 Upper Doe Run 0.332 8% 69% 76% 17%
35 Upper Marsh Creek 0.312 12% 36% 48% 34%
16 Brandywine Creek 0.279 0% 26% 26% 39%
18 Brandywine Creek 0.252 2% 19% 21% 38%
25 Broad Run 0.247 0% 41% 41% 30%
13 Brandywine Creek East Br. 0.205 0% 14% 14% 48%
32 Birch Run 0.194 16% 16% 32% 53%
10 Brandywine Creek East Br. 0.158 0% 36% 36% 40%
5 Brandywine Creek West Br. 0.158 0% 19% 19% 35%
11 Brandywine Creek East Br. 0.153 0% 33% 33% 36%
12 Brandywine Creek East Br. 0.152 0% 11% 11% 39%
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1 Upper Brandywine Creek West Br.
0.092 46% 22% 68% 20%
17 Brandywine Creek 0.082 0% 27% 27% 49%
6 Brandywine Creek West Br. 0.064 4% 36% 40% 35%
7 Brandywine Creek West Br. 0.064 0% 49% 49% 38%
24 Trib. To Broad Run 0.057 0% 3% 3% 8%
26 Marsh Creek 0.053 7% 20% 26% 60%
3 Brandywine Creek West Br. 0.030 7% 23% 30% 40%
8 Brandywine Creek West Br. 0.024 0% 62% 62% 25%
23 Lower Buck Run 0.022 5% 44% 49% 49%
2 Brandywine Creek West Br. 0.021 9% 19% 28% 46%
4 Brandywine Creek West Br. 0.002 0% 15% 15% 69%
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Table 3-8 – Top 12 Brandywine Subwatersheds Ranked by Cryptosporidium Score and Livestock Land use
Reach #
Stream Name Crypto score
% Agricultural
- Pasture Hay
% Agricultural - Row Crops
% Agricultural
land total
% forested
1 Upper Brandywine Creek West Br.
0.092 46% 22% 68% 20%
9 Upper Brandywine Creek East Br.
0.350 27% 27% 54% 33%
32 Birch Run 0.194 16% 16% 32% 53%
35 Upper Marsh Creek 0.312 12% 36% 48% 34%
2 Brandywine Creek West Br.
0.021 9% 19% 28% 46%
27 Marsh Creek 0.513 9% 21% 29% 34%
22 Lower Doe Run 0.356 8% 71% 79% 18%
21 Upper Doe Run 0.332 8% 69% 76% 17%
3 Brandywine Creek West Br.
0.030 7% 23% 30% 40%
26 Marsh Creek 0.053 7% 20% 26% 60%
20 Upper Buck Run 0.823 6% 53% 59% 25%
23 Lower Buck Run 0.022 5% 44% 49% 49%
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Table 3-9 - Final Ranking of Subwatersheds for Agriculture Incorporating Factors for Dairy Farms and Cows in Stream
Reach #
Stream Name Ag mitigation load/land
score
Dairy livestock factor (H,
M, L, U)
Diary Score
Ag mitigation combined
score
1 Upper Brandywine Creek West Br.
0.93 H 3 3.93
9 Upper Brandywine Creek East Br.
0.63 H 3 3.63
35 Upper Marsh Creek 0.32 H 3 3.32
22 Lower Doe Run 0.25 M 2 2.25
23 Lower Buck Run 0.10 M 2 2.10
31 Pocopson Creek 0.09 M 2 2.09
32 Birch Run 0.36 L 1 1.36
2 Brandywine Creek West Br. 0.19 L 1 1.19
19 Brandywine Creek 0.13 L 1 1.13
18 Brandywine Creek 0.11 L 1 1.11
16 Brandywine Creek 0.07 L 1 1.07
17 Brandywine Creek 0.02 L 1 1.02
29 Valley Creek 0.39 U 0 0.39
34 Lower Brandywine Creek 0.38 U 0 0.38
30 Beaver Creek 0.34 U 0 0.34
20 Upper Buck Run 0.32 U 0 0.32
27 Marsh Creek 0.31 U 0 0.31
21 Upper Doe Run 0.24 U 0 0.24
33 Rock Run 0.20 U 0 0.20
3 Brandywine Creek West Br. 0.16 U 0 0.16
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Reach #
Stream Name Ag mitigation load/land
score
Dairy livestock factor (H,
M, L, U)
Diary Score
Ag mitigation combined
score
26 Marsh Creek 0.14 U 0 0.14
28 Trib. To Valley Creek 0.13 U 0 0.13
14 Brandywine Creek East Br. 0.12 U 0 0.12
15 Brandywine Creek 0.10 U 0 0.10
6 Brandywine Creek West Br. 0.10 U 0 0.10
25 Broad Run 0.06 U 0 0.06
13 Brandywine Creek East Br. 0.05 U 0 0.05
10 Brandywine Creek East Br. 0.04 U 0 0.04
5 Brandywine Creek West Br. 0.04 U 0 0.04
11 Brandywine Creek East Br. 0.04 U 0 0.04
12 Brandywine Creek East Br. 0.04 U 0 0.04
7 Brandywine Creek West Br. 0.02 U 0 0.02
24 Trib. To Broad Run 0.01 U 0 0.01
8 Brandywine Creek West Br. 0.01 U 0 0.01
4 Brandywine Creek West Br. 0.00 U 0 0.00
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Figure 3-4 – Priority Areas for Agricultural Mitigation To Protect Wilmington’s Water Supply
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Figure 3-5 – Location of Honey Brook Farm Clusters for Top Priority Agricultural Mitigation Activities to Protect Wilmington’s Water Supply
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3.4.2. Priority Areas For Stormwater Mitigation
The priority areas for stormwater were ranked by using the weighted contaminant loading scores, the percentage of impervious land, and the percentage of urban/residential land in a subwatershed to determine an overall stormwater score. An initial stormwater load score was calculated as follows:
Stormwater load score = % urban&residential land use + 2 X % impervious land use + 2 X weighted average contaminant loading score
Then additional land use and ordinance factors were used to calculate an overall stormwater mitigation score as follows:
Overall stormwater mitigation score = (%urban&residential land use to % agricultural land ratio + % urban&residential land use to % forested land ratio) / 10 + stormwater load score - ordinance factor
Based on this scoring system the top watersheds were identified in Tables 3-10 and 3-11 and Figure 3-6. In each of the subwatersheds specific mitigation activities will need to be identified. For example in subwatershed 15, there is already a mitigation project underway with the Brandywine Valley Watershed Association for Plum Run and Radley Run. In subwatershed 34, partnerships with New Castle County and the continued implementation of the WRPA ordinance and Wilmington’s proposed WRPA ordinance are critical activities to addressing stormwater in addition to the movement to impervious cover parcel based stormwater billing in this area of Delaware. In the East Branch subwatersheds, specifically in the Valley Creek and Beaver Creek subwatersheds (including their tributaries), increased stringency of stormwater ordinances for development and retrofitting of existing basins for additional infiltration is recommended as an interim step until a stormwater utility can be established in these areas. These areas would also be priority areas to focus any watershed based reforestation programs.
Subwatersheds 12, 13, and 19 also have dual priorities. Subwatersheds 12 and 13 are also priority areas for forest preservation in addition to stormwater mitigation. The synergy of riparian forest preservation and open space preservation in these areas to prevent the worsening of stormwater issues will also help towards laying groundwork for stormwater mitigation projects. These subwatersheds also represent a good opportunity to merge reforestation efforts with forest preservation efforts for a greater overall improvement.
In Subwatershed 19, it is a stormwater priority area and an agricultural mitigation priority area due to the close proximity to the Wilmington intake and thus any activities in or near the stream, floodplain, or waterways have a direct and immediate negative potential impact on Wilmington’s water quality.
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Table 3-10 - Top Watersheds for Stormwater Mitigation
Subwatershed /Reach
#
Stream Name % Ag land total
% forested
Urban / Residential total
Impervious total
Overall Stormwater Mitigation Score
34 Lower Brandywine Creek 2% 14% 62% 29% 5.75
24 Trib. To Broad Run 3% 8% 88% 10% 4.74
28 Trib. To Valley Creek 3% 21% 67% 23% 4.11
29 Valley Creek 21% 35% 33% 13% 2.03
19 Brandywine Creek 4% 17% 34% 9% 1.94
30 Beaver Creek 32% 30% 33% 9% 1.75
12 Brandywine Creek East Br. 11% 39% 45% 13% 1.36
5 Brandywine Creek West Br. 19% 35% 39% 16% 1.19
14 Brandywine Creek East Br. 32% 30% 32% 9% 1.12
15 Brandywine Creek 41% 17% 34% 7% 1.09
13 Brandywine Creek East Br. 14% 48% 31% 10% 0.95
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Table 3-11 – Ranking of Subwatersheds for Stormwater Mitigation in the Brandywine Creek
Reach # Stream Name % Ag land total
% forested Urban / Residential
total
Impervious total
Overall Stormwater Mitigation
Score
34 Lower Brandywine Creek 2% 14% 62% 29% 5.75
24 Trib. To Broad Run 3% 8% 88% 10% 4.74
28 Trib. To Valley Creek 3% 21% 67% 23% 4.11
29 Valley Creek 21% 35% 33% 13% 2.03
19 Brandywine Creek 4% 17% 34% 9% 1.94
30 Beaver Creek 32% 30% 33% 9% 1.75
12 Brandywine Creek East Br. 11% 39% 45% 13% 1.36
5 Brandywine Creek West Br. 19% 35% 39% 16% 1.19
14 Brandywine Creek East Br. 32% 30% 32% 9% 1.12
15 Brandywine Creek 41% 17% 34% 7% 1.09
13 Brandywine Creek East Br. 14% 48% 31% 10% 0.95
20 Upper Buck Run 59% 25% 13% 3% 0.91
27 Marsh Creek 29% 34% 26% 3% 0.86
16 Brandywine Creek 26% 39% 33% 5% 0.86
31 Pocopson Creek 49% 22% 27% 3% 0.79
33 Rock Run 42% 30% 21% 4% 0.76
25 Broad Run 41% 30% 27% 6% 0.72
11 Brandywine Creek East Br. 33% 36% 26% 7% 0.68
18 Brandywine Creek 21% 38% 19% 5% 0.62
3 Brandywine Creek West Br. 30% 40% 28% 4% 0.54
10 Brandywine Creek East Br. 36% 40% 22% 3% 0.53
6 Brandywine Creek West Br. 40% 35% 23% 4% 0.48
2 Brandywine Creek West Br. 28% 46% 24% 4% 0.47
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9 Upper Brandywine Creek East Br.
54% 33% 8% 1% 0.42
17 Brandywine Creek 27% 49% 17% 4% 0.41
35 Upper Marsh Creek 48% 34% 9% 2% 0.40
32 Birch Run 32% 53% 14% 2% 0.39
21 Upper Doe Run 76% 17% 5% 1% 0.37
4 Brandywine Creek West Br. 15% 69% 14% 5% 0.36
22 Lower Doe Run 79% 18% 3% 1% 0.35
26 Marsh Creek 26% 60% 13% 3% 0.31
1 Upper Brandywine Creek West Br.
68% 20% 8% 2% 0.28
7 Brandywine Creek West Br. 49% 38% 10% 2% 0.25
8 Brandywine Creek West Br. 62% 25% 11% 2% 0.24
23 Lower Buck Run 49% 49% 0% 0% 0.02
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Figure 3-6 - Priority Areas for Stormwater Mitigation To Protect Wilmington’s Water Supply
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3.4.3. Priority Non-Point Sources – High Priority Geographical Areas for Preservation
Tables 3-12 & 3-13 and Figures 3-7 and 3-8 show the high priority subwatershed areas for agricultural and forest preservation. These were calculated using the following metrics and scores.
Preservation score = ((1 - % urban/residential land) * 2) + ( % forested land * %agricultural row crops land * 0.5) - (weighted contaminant load score * 2)
Ag preservation score = IF( %row crops land>0.04,1,0) + IF(% agricultural land total >0.3,1,0) + IF(weighted contaminant load score<0.1,1,0)
Forest preservation score = IF(weighted contaminant load score <0.1,0.5,0) + IF(weighted contaminant load score <0.01,0.5,0) + IF(% forested land>0.3,1,0) + IF(% urban/residential land <0.2,1,0)
Water supplier benefit score = # of water intakes downstream that benefit from the preservation in a given subwatershed
Overall Preservation Score = forest preservation rank + water supplier benefit score
Using these various scores the top subwatersheds were ranked by overall preservation score. This information was also compared with the agricultural preservation score to identify “synergy areas” where forest preservation activities could be synchronized with agricultural mitigation and preservation activities (Table 3-14). As shown the subwatersheds #9 and 35, the Upper Marsh Creek and Upper East Branch (including Perkins Run and Indian Run shown in Figure 3-9), are two high priority subwatersheds for forest preservation, agricultural preservation, and agricultural mitigation. Thus these areas serve as top priority areas for preservation activities due to the multiple potential partners and funding sources and greater chances for success. Second tier top priority areas included subwatersheds 4 (W. Branch at Coatesville), 12 (E. Branch), and 13 (E. Branch). Second tier top priority forested preservation areas include the lower section of the Upper East Branch (subwatersheds 12 & 13) and the West Branch at Coatesville (subwatershed 4).
Since most of the high priority and second priority areas for preservation were in the Upper East Branch of the Brandywine Creek, efforts to identify even smaller subwatersheds for further prioritization were conducted. Detailed priority cluster areas were determined by working with the Brandywine Conservancy. Existing prioritization of preservation areas have been conducted for the Upper East Branch (UEB) as part of a DCNR study in 2004. The Upper East Branch priority cluster is also one of the areas with the greatest potential. In the UEB study the top priority subwatersheds in the Upper East Branch for forested stream corridor preservation were Upper Marsh Creek, Perkins Run, and Indian Run (especially the North Branch) see Figure 3-10. Using the riparian buffer gap areas and estimates from this report specific areas and costs were used to estimate and determine how preservation of the forested areas could be achieved to protect the water supplies of the watershed. More information on the costs and metrics of progress are in section 7.
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Table 3-12 – Top Priority Areas for Forest Preservation for Long Term Protection of Wilmington’s Water Supply
Preservation Priority
Reach # Stream Name
Ag preservation rank (0-3, 3
best)
Forest preservation rank (0-3,3
best) Type of Preservation
Water Supplier benefit score
Overall Preservation
Score
Primary 26 Marsh Creek 2 2.5 Synergy w/ag efforts 3 5.5
Primary 35 Upper Marsh Creek 2 2 Synergy w/ag efforts 3 5
Primary 9 Upper Brandywine Creek East
Br. 2 2 Synergy w/ag efforts 3 5
Primary 11 Brandywine Creek East Br. 2 1.5 Synergy w/ag efforts 3 4.5
Primary 10 Brandywine Creek East Br. 2 1.5 Synergy w/ag efforts 3 4.5
Secondary 13 Brandywine Creek East Br. 1 1.5 Forest / riparian
corridor 3 4.5
Secondary 12 Brandywine Creek East Br. 1 1.5 Forest pres 3 4.5
Secondary 4 Brandywine Creek West Br. 1 3 Forest pres 1 4
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Table 3-13 – Top Priority Areas for Agricultural Preservation
Reach # Stream Name Ag preservation rank (0-3, 3
best)
Forest preservation rank (0-3,3
best)
Water Supplier benefit score
Overall Preservation
Score
3 Brandywine Creek West Br. 3 1.5 2 3.5
1 Upper Brandywine Creek West Br.
3 1.5 2 3.5
32 Birch Run 3 2.5 2 4.5
23 Lower Buck Run 3 3 1 4
33 Rock Run 2 0 1 1
22 Lower Doe Run 2 1 1 2
21 Upper Doe Run 2 1 1 2
20 Upper Buck Run 2 1 1 2
25 Broad Run 2 1.5 1 2.5
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Table 3-14 – Ranking of Areas for Agricultural and Forest Preservation in the Brandywine Creek for Water Supply Protection
Reach # Stream Name Ag preservation rank (0-3, 3
best)
Forest preservation rank (0-3,3
best)
Water Supplier benefit score
(0-4, 4 best)
Overall Preservation
Score
26 Marsh Creek 2 2.5 3 5.5
35 Upper Marsh Creek 2 2 3 5
9 Upper Brandywine Creek East Br.
2 2 3 5
32 Birch Run 3 2.5 2 4.5
13 Brandywine Creek East Br. 1 1.5 3 4.5
12 Brandywine Creek East Br. 1 1.5 3 4.5
11 Brandywine Creek East Br. 2 1.5 3 4.5
10 Brandywine Creek East Br. 2 1.5 3 4.5
23 Lower Buck Run 3 3 1 4
4 Brandywine Creek West Br. 1 3 1 4
18 Brandywine Creek- main stem downstream of Smith’s Bridge
1 2.5 1 3.5
17 Brandywine Creek – main stem 1 2.5 1 3.5
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Reach # Stream Name Ag preservation rank (0-3, 3
best)
Forest preservation rank (0-3,3
best)
Water Supplier benefit score
(0-4, 4 best)
Overall Preservation
Score
to Smith’s Bridge
7 Brandywine Creek West Br. 2 2.5 1 3.5
5 Brandywine Creek West Br. 1 1.5 2 3.5
3 Brandywine Creek West Br. 3 1.5 2 3.5
1 Upper Brandywine Creek West Br.
3 1.5 2 3.5
25 Broad Run 2 1.5 1 2.5
8 Brandywine Creek West Br. 2 1.5 1 2.5
6 Brandywine Creek West Br. 2 1.5 1 2.5
2 Brandywine Creek West Br. 2 1.5 1 2.5
29 Valley Creek 0 1 1 2
27 Marsh Creek 1 1 1 2
22 Lower Doe Run 2 1 1 2
21 Upper Doe Run 2 1 1 2
20 Upper Buck Run 2 1 1 2
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Reach # Stream Name Ag preservation rank (0-3, 3
best)
Forest preservation rank (0-3,3
best)
Water Supplier benefit score
(0-4, 4 best)
Overall Preservation
Score
16 Brandywine Creek 0 1 1 2
14 Brandywine Creek East Br. 1 1 1 2
24 Trib. To Broad Run 1 0.5 1 1.5
34 Lower Brandywine Creek 0 0 1 1
33 Rock Run 2 0 1 1
31 Pocopson Creek 1 0 1 1
30 Beaver Creek 1 0 1 1
28 Trib. To Valley Creek 0 0 1 1
19 Brandywine Creek 0 0 1 1
15 Brandywine Creek 1 0 1 1
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Figure 3-7 - Priority Areas for Forest Preservation To Protect Wilmington’s Water Supply
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Figure 3-8 - Priority Areas for Agricultural Preservation To Protect Wilmington’s Water Supply
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Figure 3-9 – Perkins Run and Indian Run Top Forest Preservation Priority Areas to Protect Wilmington’s Water Supply
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Figure 3-10 – Stream Corridor Preservation Priorities in the Upper East Branch – (used with permission from the Brandywine Conservancy Watershed Conservation
Plan, 2004)
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Figure 3-11– Map of Overlapping Priority Areas
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Figure 3-12 – Top Agricultural and Stormwater Mitigation Areas to Protect Wilmington’s Water Supply
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Figure 3-13 – Agricultural and Forest Preservation Priority Areas to Protect Wilmington’s Water Supply
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3.4.4. Priority Non-Point Sources – High Priority Geographical Areas for Riparian Buffer Restoration, Reforestation, and Preservation
In the previous section, preservation of prioritization of forested riparian buffers in largely pristine areas was discussed. However, in many cases it is difficult within any given parcel to just preserve the riparian buffer because it is intermittently disturbed by various human activities past and present. Therefore, it is more realistic to assume that any riparian buffer preservation activities will need to be conducted in conjunction with riparian buffer reforestation and restoration. Also, since a similar analysis to that conducted for the Upper East Branch of the Brandywine Creek has not been conducted watershed wide, only limited information is available or needs to be created for other areas of the watershed.
With this limited information a limited screening for prioritization to identify additional clusters or prioritize amongst the remaining priority was conducted using forested areas, current area preserved/protected and including factors such as proximity to the Wilmington intake. This created the ability to prioritize the areas on the main stem Brandywine to the Wilmington intake for preservation. Using these factors, preservation on the West branch was determined to only be feasible in combination with agricultural preservation and stream corridor efforts on a case by case basis given the dominant impacts of and opportunities with agriculture and agricultural preservation (see Figures 3-11 to 3-13). The remaining areas in the Lower Main stem Brandywine below Chadds Ford and into New Castle County were determined to be the most important of the secondary preservation areas due to their location immediately upstream of the Wilmington intake.
Examining the area along the main stem of the Brandywine in more depth, it appears the area above Smith’s Bridge is either protected by existing parks/open space, railways or roadways that create a limited buffer to development along or near the stream and thus provide some limited preservation along the stream. Therefore, riparian buffer preservation, reforestation, and restoration in the Lower Main stem will need to be focused on opportunities and priorities within the tributaries to the main stem. Within the Lower Main stem a general screening for prioritization of preservation areas were identified below Chadds Ford to the PA border by examining the current protected and preserved lands, the potential for connection of forested stream corridors within tributaries to the lower mainsteam and overall existing forested stream corridors within the tributaries. Based on this analysis the following tributaries were ranked as shown in Table 3-15. The results suggest that the completion of forest preservation in Ramsey Run, Rocky Run/Hurricane Run, and Beaver Creek and Craigs Mill Run should be completed first. Given the amount of land in this area attributed to golf courses these may be good initial starting areas for riparian buffer restoration and preservation efforts.
The only tributary to the main stem not included in this analysis was Pocopson Creek due to its large size compared to the other tributaries and proximity to the confluence of the East and West Branches of the Brandywine Creek. Field surveys of the Pocopson Creek have identified cows in the stream, some large continuous tracks of fully buffered stream sections, and large continuous tracks of stream in agricultural lands. Given on the ground observations as compared to the desktop values, the Pocopson Creek should be considered
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as an additional area for agricultural preservation work coordination with the recommended agricultural mitigation and reforestation efforts.
Given the results of the screening a more in depth analysis was conducted to obtain more detailed information. The Brandywine Conservancy donated staff time to this effort and conducted a GIS analysis that identified areas of potential riparian buffer gaps, protected lands, and lower main stem area was then evaluated for specific tributaries and areas for future preservation or reforestation efforts within Delaware or near the PA border. It is important to acknowledge that the following part of this section was compiled, analyzed, produced, and published by the Brandywine Conservancy (Anderson, 2008) and was extremely useful to the future prioritization of riparian buffer efforts in the Lower Brandywine main stem.
The land use and land cover within the Delaware portion of the watershed used in the analysis was based on a statewide land use layer produced in 2007. From this coverage it was determined that single family dwellings are the single largest land use/cover type (24 percent), followed by deciduous forest (22 percent). Farmland comprised 12 percent of the Delaware portion of the watershed and is concentrated west of Route 202 near the Pennsylvania border as mentioned earlier near Smiths Bridge (see Figure 3-14 and Table 3-16). A relatively high proportion (10 percent) of land is in recreational use (golf courses and state, city, and county parks). Portions of four golf courses fall within the Delaware portion of the watershed, including the Biderman Golf Course near Winterthur and the golf courses at Brandywine Country Club, Wilmington Country Club, and Dupont Country Club. The opportunities at golf courses related to riparian buffers are discussed later in this section.
Figure 3-15 shows the 2007 land use and land cover within riparian buffers, defined as areas of land within 100 feet of a stream centerline or body of water. Roughly 1,636 acres of land or 11% of the total Delaware portion of the watershed is within the 100 foot buffer. Of the 1,636 acres of land within riparian buffers, 45 percent is in forest cover. The next greatest land use/land cover type within riparian buffers is single family dwellings (17 percent), followed by farmland (9 percent), urban/built-up (8 percent), and recreational (8 percent). Such variability suggests that any program aimed at reforesting or improving management of all buffer lands should be designed to reach small-lot landowners as well as larger estate, farmland, and institutional landowners.
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Table 3-15 – Priority Lower Main stem Tributaries for Protection & Preservation Efforts
Tributary Total
Length
(km)
Length
needing
forest/open
space
length
w/forest/open
space
%
protected
%
unprotected
L or R
side
looking
upstream
sequence
from
intake
protection
score
Ramsey Run 1.4 0.7 0.7 50% 50% R 2 1.30
Rocky Run/Hurricane
Run
4.8 0.9 3.9 81% 19% R 1 1.09
Beaver Creek 15 4.7 10.3 69% 31% R 3 1.01
Craigs Mill Run 8.2 3.2 5 61% 39% L 4 0.99
Ring Run 8.7 4.3 4.4 51% 49% L 7 0.79
Harvey Run 16.3 6.1 10.2 63% 37% R 6 0.77
Wilson Run 2.7 0.45 2.25 83% 17% R 5 0.67
Bennetts Run 10.9 4.5 6.4 59% 41% L 9 0.51
Brinton Run 5.2 1.1 4.1 79% 21% R 8 0.41
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Figure 3-16 and Table 3-17 shows that close to 40 percent of land within the Delaware portion of the Brandywine Creek watershed is in some form of protection, whether eased or owned by a land trust, public agency, nonprofit organization, or homeowners association. “Protection status” does not speak to the management of these lands for water quality purposes (i.e. protected lands may not have adequate riparian forest buffers), but generally indicates that they are off-limits to future residential or commercial development. With close to 40 percent of the watershed in some form of protection, targeted outreach to, and/or program implementation through, a few key land trusts (including the Brandywine Conservancy), nonprofits, and government agencies could have far reaching positive impacts on water quality.
Figure 3-17 shows that close to 16 percent of protected lands within the Delaware portion of the Brandywine Creek watershed is within the 100 foot buffer. Of the 1,636 acres of land within riparian buffers, roughly 56 percent is in some form of protection. This strengthens the need for targeting outreach to and/or implementing best management practices in cooperation with the owners and easement holders of protected lands. As presented in Figure 3-17, these lands generally offer greater opportunity for buffer reforestation and enhancement. Such an approach may also prove more cost-effective than a program aimed at all riparian buffer landowners.
Based on these results an effort to get even more detailed forested land use information for stream buffer restoration was conducted. Higher resolution data captured from aerial photographs and limited ground-truthing in 2002 indicates that roughly 32 percent of the Delaware portion of the watershed is forested, more than the amount identified with the coarser land use/land cover data presented in Figure 3-18 based on 2007 data. Comparison of the two land cover datasets indicates that this older one may potentially be more accurate. Therefore, it is used as the basis for the final riparian buffer forested cover and prioritization analysis depicted in Figures 3-18 and 19 and Tables 3-18.
As shown in Figure 3-20 nearly 60 percent of the land within riparian buffers is forested. This exceeds the estimate presented in Figure 3-17. Roughly 30 percent of riparian buffers are not forested and not developed, suggesting that close to one-third of riparian buffers in the Delaware portion of the watershed (484 acres) could be reforested or enhanced.
Synthesizing information presented in Figures 3-15 through 3-19, Figure 3-20 identifies potential gaps in riparian forest cover throughout the Delaware portion of the watershed. All tax parcels with gaps in riparian forest cover are highlighted, with the top 30 ranked by the acreage of non-forested riparian buffer area per parcel. These 30 parcels – in some cases owned by the same landowner – contain 277 acres of non-forested riparian buffer land, roughly 57 percent of all non-forested riparian buffer land in the Delaware portion of the watershed. Agriculture, including hay, row crops, and pasturage, is the most common land use of the top 30 (11 parcels), followed by golf courses (6 parcels) and parks (5 parcels). Twenty of the top 30 “reforestation opportunity parcels” are in some form of protection.
The two top priority riparian reforestation areas appear to be the Wilson Run Cluster (areas 1, 5, 8, 16, 20) and the Smith Bridge Road Agricultural Corridor Cluster (areas 4, 5, 11, 14, 17, 22, 28) which includes the Beaver Creek, Ramsey Run, and unnamed tributary (see
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Table 3-19 and Figure 3-20). Both of these clusters of parcels only involve a handful of landowners and already possess some protected lands suggesting they may be open to riparian buffer restoration efforts. Also, these clusters possess a variety of land uses. The Smith Bridge Road Cluster is mostly agricultural land with cows in the headwater streams. The Wilson Run Cluster is mostly gardens, but also has a significant golf course area. These both represent opportunities to pilot and demonstrate how better management of riparian corridors at golf courses and agricultural lands on headwater tributaries can be conducted effectively for watershed wide application.
Within the two major clusters, the greatest priority areas are areas 1, 5, 8, and 28 due to the presence of cows in the stream or other activities that could have a direct impact on water quality at Wilmington’s intake. In the future, actions to verify these gaps and meet with the key stakeholders/property owners to determine ways to improve the riparian buffers within these key parcels will need to be determined. Also, future watershed monitoring by COW may want to focus on establishing a baseline at these top priority tributaries so as riparian buffer improvements are made they can be measured and quantified.
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Table 3-16 – Land Use within the Delaware Portion and 100 ft Riparian Buffer of the Brandywine Creek Watershed (Source: Brandywine Conservancy, 2008)
Land Use/Land Cover Type Acres % of
Watershed Acres
% of Riparian
Buffer Area
Single Family Dwellings 3,566.8 24.30 256.8 15.69
Multi Family Dwellings 165.6 1.13 2.9 0.17
Mobile home Parks/Courts 22.4 0.15 0.0 0.00
Commercial 1,098.0 7.48 70.9 4.33
Junk/Salvage Yards 8.8 0.06 3.2 0.20
Retail Sales/Wholesale/Professional Services 1,089.1 7.42 67.7 4.14
Industrial 114.5 0.78 10.6 0.64
Transportation/Communication 346.4 2.36 19.7 1.20
Highways/Roads/Access roads/Freeways/Interstates 248.1 1.69 5.2 0.32
Parking Lots 11.1 0.08 0.3 0.02
Railroads 87.2 0.59 14.1 0.86
Utilities 0.0 0.00 0.0 0.00
Mixed Urban or Built-up Land 1,476.9 10.06 130.9 8.00
Mixed Urban or Built-up Land 621.4 4.23 16.2 0.99
Other Urban or Built-up Land 855.5 5.83 114.8 7.01
Institutional/Governmental 623.6 4.25 34.9 2.13
Recreational 1,474.7 10.05 129.9 7.94
Farms, Pastures, and Cropland 1,778.1 12.12 144.5 8.83
Cropland 1,579.2 10.76 132.6 8.11
Farmsteads and Farm Related Buildings 72.0 0.49 7.0 0.43
Idle Fields 32.1 0.22 0.0 0.00
Pasture 94.8 0.65 4.8 0.30
Rangeland 47.4 0.32 10.0 0.61
Herbaceous Rangeland 37.3 0.25 4.5 0.27
Mixed Rangeland 10.2 0.07 5.6 0.34
Deciduous Forest 3,289.2 22.41 726.2 44.39
Evergreen Forest 11.4 0.08 0.2 0.01
Mixed Forest 33.5 0.23 1.4 0.09
Shrub/Brush Rangeland 40.3 0.27 8.3 0.51
Man-made Reservoirs and Impoundments 87.5 0.60 10.4 0.63
Open Water 231.4 1.58 29.9 1.83
Bays and Coves 31.4 0.21 3.1 0.19
Non-tidal Open Water 7.2 0.05 5.5 0.34
Waterways/Streams/Canals 192.8 1.31 21.3 1.30
Emergent Wetlands - tidal and non-tidal 36.5 0.25 21.4 1.31
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Land Use/Land Cover Type Acres % of
Watershed Acres
% of Riparian
Buffer Area
Non-tidal Emergent Wetland 22.5 0.15 13.7 0.84
Tidal Emergent Wetland 14.0 0.10 7.8 0.47
Non-tidal Forested Wetland 16.0 0.11 11.1 0.68
Non-tidal Scrub/Shrub Wetland 2.4 0.02 1.0 0.06
Tidal Shoreline 2.1 0.01 1.6 0.10
Transitional (incl. cleared, filled, and graded areas) 211.9 1.44 13.7 0.84
Table 3-17 – Summary of Protected Lands within the Delaware Portion and 100 ft Riparian Buffer of the Brandywine Creek Watershed (Source: Brandywine Conservancy, 2008)
Protected Land Type Acres % of
Watershed
Acres within Riparian Buffer
% of Riparian Buffer Area
Riparian/ Watershed
Lands Owned or Eased by Land Trusts 2009.1 13.7 312.9 19.1 16%
Public Lands 1921.3 13.1 301.8 18.4 16%
Non-Profit Institution Lands 1715.6 11.7 291.1 17.8 17%
Homeowners Association Lands 36.4 0.3 12.1 0.7 33%
Sum 5682.4 38.8 917.9 56.1 16%
Table 3-18 – Summary of Final Forested Lands within the Delaware Portion and 100 ft Riparian Buffer of the Brandywine Creek Watershed (Source: Brandywine Conservancy, 2008)
Land Cover Type Acres % of Watershed Acres (of Riparian
Buffer)
% of Total Buffer
Developed 2,984.3 20.3 128.5 7.9
Forested 4,621.7 31.5 978.5 59.8
Non-Forested 6,678.0 45.5 484.3 29.6
Water/Wetland 325.1 2.2 41.8 2.6
Missing data* 70.9 0.5 2.9 0.2
Sum 14,680.0 100.0 1,636.0 100.0 *The land cover layer does not match the Brandywine Creek watershed boundary due to differences in data collection
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Table 3–19 - Priority Areas for Riparian Buffer Restoration in New Castle County – (Source: Brandywine Conservancy, 2008)
Rank Non-Forested Buffer Acreage Land Use* Protected^ Notes
1 38.57 Institutional/Agriculture Yes hay
2 25.84 Golf Course No
3 17.44 Agriculture Yes mixed
4 15.99 Golf Course No
5 15.34 Agriculture No mixed
6 13.67 Institutional (Hospital) Yes
7 10.77 Agriculture Yes hay
8 9.76 Golf Course No
9 9.63 Park Yes
10 8.59 Agriculture Yes crops
11 8.48 Institutional/Agriculture Yes hay
12 7.71 Institutional (Museum) Yes
13 7.48 Agriculture Yes mixed
14 7.00 Residential (HOA land) Yes
15 6.53 Golf Course Yes
16 6.50 Agriculture Yes mixed
17 6.41 Golf Course No
18 5.52 Golf Course Yes
19 5.37 Agriculture No crops/dairy production
20 5.29 Agriculture Yes hay/horses
21 5.01 Residential (HOA land) Yes
22 4.97 Park Yes
23 4.91 Institutional (College) No
24 4.56 Agriculture Yes mixed
25 4.48 Park Yes
26 4.43 Park Yes
27 4.39 Commercial No
28 4.33 Park Yes
29 4.11 Residential No
30 3.77 Agriculture No hay/horses
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Figure 3-14
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Figure 3-15
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Figure 3-16
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Figure 3-17
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Figure 3-18
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Figure 3-19
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Figure 3-20
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The Brandywine Conservancy also conducted an additional GIS screening of potential riparian buffer opportunities in the Brandywine Creek. This prioritization was conducted using the similar methodologies discussed previously in this section. Tables 3- 20 and 21 summarize the potential amounts of riparian buffer opportunities in the watershed. As shown all the sections of the watershed except the main stem portion of the Brandywine in Delaware had over 50% to 60% riparian buffer opportunities. When examined on a percentage basis it appears that the Upper East Branch and Central Brandywine sections have the greatest potential riparian buffer areas and potential riparian buffer opportunities. Figures 3-21 to 25 show the riparian areas in each watershed. The numbered areas in the figures identify the larger potential riparian opportunities.
Table 3- 20 – Acres of Potentially Buffered and Non-Buffered Riparian Areas In Sections of The Brandywine Watershed
Section of Watershed
Buffered Riparian (acres)
Riparian Opportunity
(acres) Total
(acres) %
opportunity
Upper West Branch 1326.505 2006.701 3333.2 60%
Upper East Branch 2726.2 3177.83 5904 54%
Buck & Doe Run 1419.305 2178.235 3597.5 61%
Central Brandywine Creek 2134.6 3267.8 5402.4 60%
Main stem Brandywine (PA)
1824.9 2046.9 3871.8 53%
Main stem Brandywine (DE)
978.5 484.3 1462.8 33%
Total 10410.01 13161.766 23571.7 56%
Table 3- 21 – Percentage of Potentially Buffered and Non-Buffered Riparian Areas In Sections of The Brandywine Watershed
Section of Watershed
Buffered Riparian (acres)
Riparian Opportunity
(acres) Total
(acres)
Upper West Branch 13% 15% 14%
Upper East Branch 26% 24% 25%
Buck & Doe Run 14% 17% 15%
Central Brandywine Creek 21% 25% 23%
Main stem Brandywine (PA) 18% 16% 16%
Main stem Brandywine (DE) 9% 4% 6%
Total 100% 100% 100%
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Figure 3-21
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Figure 3-22
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Figure 3-23
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Figure 3-24
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Figure 3-25
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3.5. Common Priorities with Stakeholders
In reality, implementation of the preservation and mitigation areas though prioritized for Wilmington’s water supply needs may not be the order in which things may be implemented. In fact, the identification of common priority mitigation areas and preservation activities for Wilmington with the other stakeholders will ultimately result in the most quickly implemented, cost effective, sustainable, and successful projects. Therefore, though the previously described priorities are for Wilmington, flexibility of Wilmington’s SWP program to adjust to work with stakeholders will be a priority. Nonetheless, there are several common priorities that were identified between the Wilmington SWP Plan and other stakeholders that can serve as a starting point for common partnerships and efforts. Table 3-22 shows common priorities between the Wilmington SWP Plan and other stakeholder priorities.
Table 3-22– Common Priorities of the Wilmington SWP Plan with Other Previous Stakeholder Plans and Priorities
Priority Source / Type Common Priority Stakeholder Other Plans
Agriculture Honey Brook area & clusters
CCCD, Coatesville PA American
TWIG scope of work, CCC, BAP, Phase II & III
reports, DE PCS
Preservation Upper East Branch Brandywine conservancy,
Aqua PA
UEB DCNR, Watersheds/Landscapes,
CCC, BAP, DE PCS
Stormwater Mitigation Radley Run/Plum Run
BVA
Stormwater Ordinances CCWRA, WRAUD DE PCS, Phase I, II, III reports, TMDL
Stormwater Stormwater Utility NCC, WRAUD DE PCS
Point Source Accidents/Spills Aqua, Downingtown,
Coatesville, CCHD
None
Point Source NPDES Discharges Aqua, PADEP, BVA
TMDL, BAP,
Stormwater Sodium/Chloride DNREC , DELDOT None
Emerging Contaminants Trace Organics USGS None
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3.6. Brandywine Watershed / Christina Basin Clean Water Partnership Stakeholder Efforts & Projects
The Brandywine Creek Watershed is fortunate to have a number of stakeholders that are actively involved in efforts to address the various issues identified in previous sections of this report. These activities are mainly coordinated in a larger effort by the Christina Basin Clean Water Partnership. The Christina Basin Clean Water Partnership is a multi-state stakeholder and regulatory agency endorsed effort to restore the Christina River Basin and its tributaries to unimpaired status. A majority of its work is focused on identifying and implementing approaches to implement the TMDLs in the watershed to achieve meaningful environmental results. Other than the regulatory agencies such as USEPA, DNREC, and PADEP many other stakeholder organizations are involved at various levels in efforts in the Brandywine Creek Watershed. The best example of stakeholder coordination, partnering, and leveraging due to the Christina Basin Clean Water Partnership is the awarding of Watershed Initiative Grant. It was a $1 million dollar grant awarded to the Christina Basin Clean Water Partnership. The three year grant was used to study and test several agricultural and stormwater best management practices to reduce nonpoint source runoff. Some specific projects included restoration of 10,000 feet of agricultural streams and implementation of a SMARTYARD program. It also includes the following on-the-ground projects:
One stormwater retrofit project at Ashbridge Square in East Caln Township, Pennsylvania
Survey work for three nutrient-management control systems in Chester County, Pennsylvania
Treatment of 500 acres of cropland per a nutrient-management plan in Chester County, Pennsylvania
Stabilization/reforestation of 1,200 linear feet of stream bank on Ludwig Creek, a headwater to Brandywine Creek
Five water-control structures (two small basins and three crossings) in Chester County, Pennsylvania
Four nutrient-management plans
One rain garden along Cool Run, a tributary to the White Clay Creek National Wild and Scenic River in Newark, Delaware
Stream restoration along 5,000 linear feet of Pike Creek in New Castle County, Delaware, including the creation of three acres of wetlands and five acres of riparian corridor using native plants
The restoration of 350 linear feet of stream along a tributary to the Red Clay Creek in New Castle County, Delaware
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25 SMARTYARD projects
Site selection for seven wetland projects at the University of Delaware’s Agriculture Complex
The following describes some of those stakeholders and highlights some of their specific efforts in the Brandywine Creek Watershed.
Brandywine Conservancy (BC) – The Brandywine Conservancy includes the Environmental Management Center with the main goal of protecting the natural and cultural resources of the Brandywine watershed and other selected areas. To date, the Conservancy has been involved in the permanent protection of more than 41,000 acres of land through services to landowners, farmers, municipalities, and developers. This is accomplished through providing conservation services to landowners, farmers, municipalities and developers. Their professional staff also offers technical assistance and expertise for conservation and comprehensive land use planning which includes conservation easements, assistance to local governments and water protection efforts. The Conservancy has provided significant assistance to the City of Wilmington’s Source Water Protection Plan regarding items related to natural resource inventories, GIS mapping, and conservation efforts. In 2008, the City of Wilmington initiated a funding agreement with the Brandywine Conservancy that provides a $10,000 matching contribution to headwaters preservation projects.
Brandywine Valley Association (BVA) – The Brandywine Valley Association was the first small watershed association in America. BVA focuses on providing water protection and environmental education. Its current focus is on its red streams to blue program which is aimed at restoring impaired streams in the watershed. Its current restoration efforts are focused in the East Branch at Plum Run and Radley Run. The BVA is also providing assistance to the City of Wilmington in its Source Water Protection Plan by hosting a water supplier issue forum to discuss water supply issues with watershed stakeholders.
Chester County Water Resources Authority (CCWRA) – The mission of Chester County Water Resources Authority is to provide the basic science, analyses and planning necessary to protect public safety, to preserve the integrity of Chester County’s natural water resources and watershed systems, and to balance the needs of water users in support of Landscapes and planned growth for Chester County.
The CCWRA created and published Watersheds—An Integrated Water Resources Management Plan for Chester County, Pennsylvania and Its Watersheds which was adopted as a component of Landscapes, Chester County’s comprehensive land use policy plan. To encourage the implementation of Watersheds, CCWRA conducts, coordinates, and facilitates water resources management and planning activities.
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The CCWRA with its partners has ongoing programs to:
Characterize and monitor the County’s streams and ground water.
Provide scientific data, investigations, and projects to address priority concerns.
Provide reliable water resources information to municipalities, water users, and the public.
Coordinate with municipalities, water purveyors, government agencies, environmental, watershed and conservancy organizations, and others involved in activities that affect Chester County’s water resources and watersheds.
Operate Struble, Beaver Creek, Barneston, and Hibernia Dams, and Chambers Lake reservoir to protect public safety during floods and droughts.
Own and maintain nearly 200 acres of adjoining riparian lands and easements and the 80-acre Chambers Lake reservoir. Chambers Lake is a 400 million gallon water supply reservoir that is used to provide water for the Coatesville regional water supply system during droughts.
Chester County Conservation District (CCCD) – the mission of the Chester county conservation district is to provide leadership in addressing natural resource conservation in the sustainable use of those resources by the citizens of Chester County through education and technical assistance. This includes the following programs:
Erosion and Sediment Control
National Pollutant Discharge Elimination System (NPDES) Post Construction Stormwater Management
Agriculture
Education
Dirt and Gravel Road Program
Watershed Coordinator Assistance
University of Delaware, Water Resources Agency (UDWRA) - The UDWRA provides technical assistance for water resources and watershed policy and to governments in Delaware and the Delaware Valley through the University's public service, education, and research role. It’s funded by four governments - the State of Delaware, New Castle County, City of Newark, and City of Wilmington along with grants from public and private sources. The staff at the WRA utilizes an interdisciplinary team approach and specializes in technical assistance, research, and information management in the fields of water supply, water quality, and watershed management and planning. The WRA provides Local Government Water Management Assistance, Natural Resources and Infrastructure Inventory, Infrastructure and Land Use Reviews, Public Assistance and Education, and Federal,
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Regional and Statewide Grant Administration.
Aqua Pennsylvania (Aqua PA) - A national and regional water supplier, Aqua PA conducts activities to protect its water supply intake on the East Branch of the Brandywine Creek. It conducts monitoring and watershed inspections and participates in stakeholder activities and events.
Pennsylvania American Water Company (PAWC) - PAWC is a national and regional water supplier. It conducts activities that promote water supply protection for its intake at Coatesville on the West Branch of the Brandywine Creek. American Water launched an environmental grant program in 2005 and has since expanded the program into 20 states where the company provides water and wastewater services. Applicants are asked to address a source water protection need in the local community or a project that improves, restores, or protects one or more watersheds. Approximately $21,000 in grants was given in Pennsylvania in 2007 though none were in the Brandywine Creek Watershed.
Delaware Nature Society (DNS) - The DNS efforts focus in the state of Delaware primarily
on education, preservation, and conservation. Specifically it offers a variety of outdoor
programs in natural settings, preserves rare habitats, and assists in addressing
environmental concerns.
Partnership for the Delaware Estuary (PDE) – PDE was established in 1996 to take a leadership role in protecting and enhancing the Delaware Estuary. The mission of the Partnership for the Delaware Estuary, one of 28 National Estuary Programs, is to lead collaborative and creative efforts to protect and enhance the Delaware Estuary and its tributaries for current and future generations.
Some relevant programs include it Corporate Environmental Stewardship Program (CESP) and Schoolyard Habitats programs. The CESP helps corporations discover that ecological enhancement and economic savings are not mutually exclusive. The Schoolyard Habitats Program offers to help schools, institutions, and organizations create and enhance wildlife habitats.
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Section 4 – Funding, Public Outreach, & Policy Needs
4.1. Funding Sources in the Brandywine Watershed
A search of Federal Funding Databases identified over 71 different federal funding grant sources for watershed related programs (http://cfpub.epa.gov/fedfund/search1.cfm ) that distribute millions per year in federal dollars to address watershed issues. Over 27 different organizations were identified that provide funding or resources to the Brandywine Watershed (See Table 4-1). Most notably in Pennsylvania over $2.6 million dollars in grants were provided between 1999 and 2006 through the PADEP Growing Greener Program (see Appendix B for a detailed listing). Approximately $19 million was provided for conservation and preservation in Chester County from the PADCNR grants programs of the grant funding is derived from programs that are oriented around addressing non-point source pollution and the EPA 319 program. Delaware also receives 319 funding, but the portion of the Brandywine Creek Watershed is Delaware is such a small portion of the state that it can only receive small portions of funding.
It may appear on paper that many of these funding sources are adequate to address the funding needs identified in Wilmington’s Source Water Protection Plan. For example, of the 2.5 million in Growing Greener funding only roughly $500,000 was directly related to high priority projects in the SWP Plan (roughly 20%), and even this money was shared amongst the Honey Brook, Buck Run, and Doe Run areas. In addition to the final project funded the true implementation these grant sources are susceptible to significant annual fluctuations and are not consistently dedicated to specific long term projects or areas. Finally, each year significant administrative resources are expended to apply, process, and track these grants to measure effectiveness. These short term results and metrics are necessary, but lead to inefficiencies to address the needs of larger longer term watershed management programs.
If one compares the five year funding needs of the Honey Brook cluster initiative in the Wilmington SWP Plan with combined 5 year funding of past potential watershed funds, it is clear it significantly exceeds the available funding by a factor of five or greater ($500,000 over 5 years vs. $500,000 per year needed for Honey Brook). Comparing preservation, the long term average preservation rate in the watershed is roughly 1,200 acres per year. The focus area preservation rate for the Upper East Branch areas of Perkins Run and Indian Run in the COW SWPP is 1,000 acres alone at $800,000 per year. It is likely that the current preservation and conservation funds will not all be able to be allocated to this priority area, so it is assumed that roughly half of the $800,000 per year needed in the focus area will need to come from new sources.
Another funding source and approach will be necessary given the inconsistencies of funding and the clear gap between the necessary funding for the plan and current potential funding for all priorities. Wilmington may want to consider optional funding through avenues such as voluntary donations on customer’s water bills or approaching larger industrial users of Wilmington’s water to fund specific initiatives. Other options include access to the State Revolving Fund monies. According to conversations with EPA and DNREC, Wilmington
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could use Delaware SRF monies upstream in PA. However, SRF money is a loan and a cost justification of the ultimate long term savings and benefits to water treatment versus the loan costs would need to be conducted.
Overall, Wilmington will need to identify key funding opportunities and new techniques for leveraging stakeholder resources and grant sources in order to achieve the goals of the source water protection plan. In some cases, the goals of its program based on measurable results may be limited by available funding and may need to be revised at a later date. However, current financial limitations should not be the way to set watershed protection goals. The focus should be on demonstrating the need and locating the funding mechanisms.
Given the findings of this analysis the following is recommended for Wilmington to fund its SWP Plan activities:
1. Identify the appropriate current funding sources and stakeholders for a particular element of the plan
2. Determine the limitations to achieving plan goal through current funding sources
3. Identify opportunities to leverage additional existing resources and funds to achieve the plan goal
4. If shortfalls still exist explore non-traditional and new sources of funding to address the gap if desired.
5. If shortfalls exist and cannot be addressed, then goals and targets will need to be adjusted based on financial limitations until new funding sources are created.
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Table 4-1 – Potential Funding Organizations in the Brandywine Watershed
Organization Type State Organization Primary Focus/Relationship
Potential Amount or Matching Resources
Public DE DNREC 319 non-point source reduction > $100,000 /yr
Public DE DNREC State Revolving
Fund drinking water improvements > $100,000/yr
Public PA PADCNR Preservation > $1 million/yr
Public PA PA American Water
Company Watershed restoration $10,000
Public All EPA 319 non-point source reduction $ 200 million nationally in 2008
Public All EPA Targeted Watersheds
Initiative non-point source reduction $1 million to Christina Basin
Public PA PADEP - Growing Greener
& 319 non-point source reduction
$5.7 Million Statewide (319), $94 million (GG), $2.6 million in
Brandywine 1999-2006
Public All U.S. Fish & Wildlife NFWF Habitat restoration/protection $50,000 - $300,000
Public All U.S. Forest Service Forestry improvements Various
Public All U.S. Army Corps Restoration > $1 million/yr
Public PA
League of Women Voters Water Resource Education
Network Education $5,000 / yr
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Organization Type State Organization Primary Focus/Relationship
Potential Amount or Matching Resources
Public All Partnership for the Delaware Estuary Education Free stewardship programs
Public All USDA/NRCS - EQIP & CRP Agricultural
Preservation/Mitigation > $200,000 / yr
Public PA PA Sea Grant (NOAA) Planning/Studies Various
Public All Coastal Zone Management
(NOAA) Coastal Protection/Restoration Up to $100,000 / yr
Public All DELDOT & PENNDOT Highway Mitigation Programs Various
Public All National Science
Foundation Monitoring & Studies Various
Public All
U.S. Geological Survey & Dept. of Interior Heritage
Corridor Various Various
Private All William Penn Foundation Planning/Studies Various
Private All Brandywine Conservancy Conservation/Preservation Various
Private All Brandywine Valley
Association Education/Restoration Various
Private All Dupont Clear Into the
Future Preservation/Restoration Up to $300,000/yr
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Organization Type State Organization Primary Focus/Relationship
Potential Amount or Matching Resources
Private All Golf Courses Stewardship Various
Private DE Nature Conservancy
Delaware Preservation/Restoration Various
Private DE Delaware Nature Society Preservation/Education Various
Public All U of Delaware Water
Resources Agency Coordination/Planning Various
Public PA Chester County Water Resources Authority Coordination, Planning, Monitoring Various
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4.2. Public Outreach
4.2.1. Within the City of Wilmington
Within the City of Wilmington, public outreach for the Source Water Protection Plan has come through meetings with interdepartmental agencies about the plan and SWP Ordinance. Public outreach has been accomplished through handouts at Earth Day and through significant focus in the latest Consumer Confidence Report (CCR) by the City of Wilmington to all of its customers. Over 3 pages of the CCR were dedicated to the Source Water Protection Plan effort. To date, no calls, emails, or correspondence from the public about the CCR focus has been received.
Future efforts will need to focus on communicating the findings of the SWP Plan to the public without divulging security sensitive information. Also integration of the SWP Ordinance and the SWP Plan will be key in its implementation. It is recommended that the SWP Plan and its implementation by Wilmington’s Source Water Protection Program is endorsed by City Council and the public. This may involve obtaining a City Council Resolution. Prior to the resolution, key community stakeholders should be identified for focused communication about the plan and to receive input. It is also recommended an Advisory Committee including private citizens, stakeholders, and pertinent city agency leaders be formed to help inform Wilmington’s Source Water Protection Program as it implements the plan and for continuous dialogue and communication regarding progress if City Council passes a resolution requiring the plans implementation. However, general public review of portions of the SWP Plan may create security concerns due to the sensitive nature of the material and must be done very carefully.
4.2.2. Upstream Partner Outreach
Implementation of Wilmington’s Source Water Protection Plan and Program is dependent upon the involvement of upstream stakeholders. Therefore, communication and partnership with this organization is critical to its success. To date, Wilmington has met with a variety of upstream stakeholders to gather input and discuss its Source Water Protection Plan. These included regulators, conservation districts, watershed groups, conservancies, municipalities, county governments, and water suppliers. These consisted of both formal meetings at stakeholder’s offices and discussions at facilitated meetings or events. Wilmington continues to communicate its activities through the Christina Basin Partnership in order to reach the most stakeholders. On 10/3/08, the findings of the plan were presented to stakeholders for input. In addition, draft versions of the plan were distributed for stakeholder comments in late 2008. In early 2009, the plan with recommended changes by stakeholders was revised, presented, and shared with stakeholders. Specific efforts for partner projects were identified and pursued for implementation based on stakeholder input in 2009 and 2010.
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4.3. Policy Issues
4.3.1. Needed Policy Changes
Throughout the meetings with stakeholders and analysis of existing information and data in the watershed a number of policy issues were identified. These policy issues fell into general categories involving funding, stormwater, land use ordinances, highway runoff, emergency management, and land preservation.
Funding – There are significant gaps between the funding needs to make significant progress in implementing the water quality goals for the watershed and actual funding sources. A dedicated and consistent source of funding is necessary. A watershed wide restoration or watershed management fund needs to be established. The sources and mechanisms for that fund need to be explored and created by leaders in the watershed.
Stormwater – Upstream communities in New Castle County and Chester County need to develop stormwater utilities that establish and impervious cover based billing system for stormwater. Upstream MS4 permits need to have TMDL’s incorporated in a meaningful and productive manner.
Land Use Ordinances – The framework and approach of the Delaware Water Resource Protection Area related ordinances and Chester County municipal ordinances for development and stormwater management have considerable differences. A uniform set of ordinances based on watershed goals is necessary to achieve greater results. This also includes ordinances for riparian buffer protection and forest cover requirements.
Highway Runoff – Data clearly indicates that highway runoff is impacting the sodium and chloride levels in the watershed. Implementation of brining to reduce road salt activities wherever safely possible should be implemented. A pilot program along sensitive stream areas should be developed and implemented.
Emergency Management – Improvement in communication and notification of potential events between dischargers, regulated facilities, health departments, and water suppliers is needed. For example, water suppliers were not informed by health agencies about the cryptosporidiosis outbreak in West Chester, PA above Wilmington’s water intake. Downstream notification requirements in Pennsylvania and Delaware should be compared and coordinated to help protect water suppliers.
Land Preservation – It is estimated that most of the forested land in the watershed that can be developed will be developed by 2100. Thus identifying and preserving the most environmentally valuable contiguous forested lands is critical. There is no single acknowledged overall plan for detailed prioritization and implementation of forested or agricultural land preservation in the watershed. A group of stakeholders will need to form a preservation committee and develop clear goals and direction for future watershed preservation.
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5. Section 5 - Emergency Preparedness, Spill Response, & Contingency Planning
5.1. Turbidity Early Warning System
The City of Wilmington has the capability to switch from the Brandywine Creek as its main water source to the Hoopes Reservoir during periods of undesirable water quality. In order to maximize this capability, the City of Wilmington contracted the USGS to develop a turbidity early warning system that would provide advance warning of approaching turbidity spikes to the City’s intakes so it could switch to the Hoopes supply prior to the arrive of the turbidity spike. Typically during dry weather periods the turbidity is only 1-2 NTU, but during wet weather events it can exceed 200 NTU. These higher turbidities have been associated with elevated levels of other contaminants that are described in depth in section 2.3.
The first step in this process was developing potential relationships between the flow at Chadds Ford and the peak turbidity at Wilmington’s intake. It was determined from analysis of existing data that at 2,000 cfs the turbidity at the Wilmington intake exceeded 20 NTU which was greater than desired for use by Wilmington. Another analysis of the timing of the turbidity peaks was conducted by USGS. The USGS determined that when the flow at Chadds Ford reached 2,000 cfs that the turbidity spike would reach Wilmington’s intakes in less than 8 hours. This was tested in the summer of 2006 and validated against existing data. Attempts were made later in 2006 by USGS to extend the warning system to upstream stations at the bottom of the East and West Branches of the Brandywine Creek, but similar relationships like the one at Chadds Ford could not be developed.
Analysis of the raw water quality data for the Porter Filtration Plant suggests there is potential for undesirable raw water quality in the Brandywine Creek during periods when the turbidity exceeds 10 NTU. A simple estimate is provided by review of the mean daily online turbidity data at the USGS station in Wilmington shows that overall 16% of the year (58 days) the mean daily turbidity is over the 10 NTU threshold (Figure 5-1). Analysis of 96 years of flow data suggests approximately 7% or 27 days a year the 840 cfs surrogate for the 10 NTU threshold will be exceeded on the Brandywine Creek resulting in a switch over to the Hoopes reservoir (Figure 5-2). Thus, using the flow at Chadds Ford as an indicator of the potential frequency of turbidity above 10 NTU, approximately 7% or 27 days a year the threshold will be exceeded resulting in a switch to the Hoopes reservoir.
Based on the 96 years of historical data a flow at the Chadds Ford station that will trigger the turbidity threshold for more than 5 consecutive days would only occur potentially once per year assuming climate change does not vary flows beyond the historical pattern (Figures 5-3 and 5-4). Based on the historical record, the maximum duration of flow over 840 cfs at Chadds Ford was 30 days, but the 99th percentile of consecutive days over 840 cfs was only 5 days. Thus an extreme event such as a major series of hurricanes or tropical depressions would need to occur and any withdrawals made from Hoopes during these extreme periods would most likely be negated by the recharge and direct rainfall runoff to the Hoopes reservoir during these periods.
A worst case impact scenario for storage in the Hoopes Reservoir under the new 10 NTU
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withdrawal threshold suggests no significant reduction in annual storage in a typical year. If an additional 2 feet of storage was added to the Hoopes reservoir, it would create an additional 125 MG/yr of storage that would significantly offset any potential negative storage impacts from using the 10 NTU turbidity threshold to switch from the Brandywine Creek to Hoopes Reservoir (Table 5-1). However, it is still recommended that the impacts of using the new trigger on Hoopes Reservoir storage be monitored and tracked to determine any long term impacts on storage and drought planning that could not be foreseen in the planning estimates.
The turbidity peak timing relationships for Chadds Ford and the Wilmington intake should continue to be updated and refined using the new online turbidity data at the Porter intake in order to ensure the timing is adjusted to reflect future changes in weather patterns (rainfall intensity) and land use changes (more impervious cover) that have the potential to reduce the time for turbidity peaks to reach Wilmington’s intakes. If modeling tools and data are readily available for the Brandywine Creek, worst case future land use and weather pattern changes could be modeled to determine the magnitude of impact 20 to 30 years in the future due to climate change. This would be helpful in determining if future watershed changes would result in increased use of the Hoopes Reservoir and provide estimates for any planning for construction of additional storage for the Hoopes Reservoir.
There are concerns that switching to the 10 NTU threshold would cause additional difficulties in operational procedures and protocols. However, based on the changes in timing, the operational impact of using the 10 NTU threshold may allow for more lead time for staff to conduct the switch over to the Hoopes Reservoir from the Brandywine Creek. For example, using the past 25 NTU trigger, the plant only has 7 hours to switch to the Hoopes Reservoir. Using the 10 NTU trigger, the USGS equations suggest that if the peak flow was constant (i.e. the flow peaked at 840 cfs), it would take 30.5 hours for the turbidity peak to reach Wilmington (Figure 5-5). However, using this value is misleading since the peak flows often exceed 840 cfs and rapidly continue to higher flowrates. For example, the flow at Chadds Ford may reach 840 cfs, but within 3 hours later it can exceed the 25 NTU flow of 2000 cfs. Using the 25 NTU peak timing suggests 8 hours until the turbidity peak reaches Wilmington while the 10 NTU peak suggested 30.5 hours creating a significant overestimate of travel time. In order to resolve this concern, an analysis of the 15 minute flow data was conducted at Chadds Ford from 2004 to 2007 since some of the greatest flows in the past 30 years were observed during this period. The difference between the time the flow reached the 10 NTU trigger (840 cfs) and the time the flow reached the 25 NTU trigger (2000 cfs) was calculated and ranked into a cumulative density function to determine the appropriate adjustment factor to the peaking time for the 10 NTU trigger. During the period there were 31 events when the flow exceeded both 840 and 2000 cfs in a single event (Figure 5-6). Over 90% of the difference in the time the flow reaches 840 and 2000cfs at Chadds Ford is less than 8 hours with 3 hours as the median. Only 20% of the events caused the difference in time to be less than 2 hours.
Based on this analysis it suggests that adding 3 hours to the existing 8 hour time of travel prediction for the turbidity peak from the 25 NTU (2000 cfs) trigger would be a more representative description of the timing for the turbidity peak for the 10 NTU (840 cfs) trigger. Therefore, once receiving the call from the USGS station, the plant will have 11 hours to switch to the Hoopes Reservoir. This new timing does not require any significant
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changes from the current turbidity arrangement and does not eliminate the potential need for staff to come in on weekends to conduct the switchover, but does eliminate the need to conduct it outside of normal daylight hours.
Using the same flow duration analysis at Chadds Ford, the number of consecutive days at Chadds Ford above 840 cfs was used to estimate the range of consecutive days that Wilmington would potentially draw from the Hoopes Reservoir using the 10 NTU turbidity threshold. As shown in Figure 5, it was estimated that only one time a year the flow exceeds the turbidity threshold for more than 3 days (9 days per year potentially).
Figure 5-1 – Frequency of Mean Daily Turbidity at Wilmington 2006-2007
Mean Daily Turbidity at Wilmington USGS (9/06-6/07)
0102030405060708090
100110120130140150160170180190
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
cumulative probability
me
an
da
ily
tu
rbid
ity
(N
TU
)
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0%
1%
2%
3%
4%
5%
6%
7%
8%
>840cfs >3 days >5 days >7 days >10 days
Consecutive days > 840 cfs
% o
f d
ay
s in
96
ye
ars
Figure 5-2 – Frequency of Consecutive Days over Flow Trigger at Chadds Ford
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cumulative probability
# c
on
secu
tive d
ays >
840 c
fs m
ean
flo
w
Figure 5-3 – Frequency of Consecutive Days Greater Than Flow Trigger at Chadds Ford
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0
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Date
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tiv
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ay
s f
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Figure 5-4 – Observed Number of Consecutive Days Greater Than Flow Trigger at Chadds Ford (1964 to 2007)
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Wilmington Turbidity (NTU)
Figure 5-5 – Comparison of Turbidity Peak at the Wilmington Intake and Time for Peak to Reach the Wilmington Intake and Chadds Ford Flow
Note: flows continue to peak past 840 cfs, thus the 30 hour estimate is improper to use. Due to flows
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peaking beyond the 840 cfs threshold, action should be taken in under 11 hours.
Table 5-1 – Estimated Annual Impact on Hoopes
Storage Parameter Storage Impact Using
840 cfs trigger
Annual Hoopes withdrawal using 10 NTU threshold (MG/yr) 662
Hoopes Total Storage (MG) 2,000
% Hoopes storage used annually 33%
Amount recharged annually via rainfall and runoff (MG/yr) 840
Recharge – withdrawal (MG/yr) 178
Additional storage if Hoopes is raised 2 ft for safety purposes (MG/yr) 125
Estimated annual surplus/deficit of storage (MG/yr) 303
*Note: estimate is a gross estimate and does not include periods when individual rainfall events exceed the reservoir storage and are lost. Therefore any estimated surplus could be less.
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Difference Between Time Fow Reaches 840 cfs and 2000 cfs at Chadds Ford Station
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etw
ee
n 8
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tart
Figure 5-6 – Comparison of The Difference in Time That Flow Reaches 840 cfs and 2000 cfs at the USGS Chadds Ford Station for 31 Events Between 2004 and 2007 (using 15 minute flow data)
5.2. Upstream Notification & Communication
Timely and effective notification to Wilmington about upstream events that could affect water quality is desired for the following reasons:
There are over 700 regulated facilities, several major highways carrying thousands of cars and trucks per day, major railroad corridors along the stream, and agricultural activities upstream from Wilmington’s intake.
The time of travel to the Wilmington intake can range from less than a few hours to over 6 days depending on the location of an accident or the flow condition.
Though Wilmington has the ability to switch to the Hoopes Reservoir, it takes time to make the switch and has operational impacts.
Upstream disease outbreaks and sewage treatment plant upsets could impact
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regulatory monitoring and compliance.
Given that most of the watershed is upstream in another state, it is easy for events in Pennsylvania to not be reported to the proper persons in Wilmington. Therefore, it is important to set in place a process that provides opportunities for communication and notification at a variety of levels. The levels of communication and notification are the following:
Individual Facility Level – Upstream facilities have been introduced to Wilmington personnel and educated about the proper contact information and notification protocols. The focus is on getting information on upstream process upsets and accidental discharges that could impact water quality.
County Emergency Responder Level – Key emergency responders in Chester and New Castle counties are educated about the proper contact information and notification protocols. Wilmington’s notification is formally included in the water supplier notification process. The focus is on getting information and warning about upstream accidents in transportation corridors, fires, or other situations that could impact water quality.
County Health Department Level - Key public health personnel in Chester and New Castle counties are educated about the proper contact information and notification protocols. Wilmington’s notification is formally included in the water supplier notification process. The main focus of this notification is to be warned early about events related to upstream disease outbreaks that could impact Wilmington’s intake (such as cryptosporidiosis, giardiasis, or enterovirus outbreaks).
State Emergency Responder Level - Key emergency responders at PADEP and DNREC are educated about the proper contact information and notification protocols. Wilmington’s notification is formally included in the water supplier notification process. The focus is on getting additional warnings regarding upstream water quality events.
Inter-Water Supplier Level – upstream water suppliers are educated about the proper contact information and notification protocols. The focus is on getting additional warnings regarding upstream water quality events or changes in water quality. Knowing when something reaches an upstream intake and what upstream treatment techniques are or are not working is essential information to prepare for a spill that could reach the intake.
By implementing a focused outreach program to improve the notification and communication with strategic areas and organizations listed above will result in multiple layers of potential communication providing various pieces of information about potential upstream events that will lead to better responses by Wilmington personnel. It also provides redundancy in case any individual communication path is terminated due to unforeseen circumstances. At the individual facility level Table 5-2 provides recommended frequencies and types of information that Wilmington should gather during the outreach process.
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Table 5-2 – Recommended Individual Facility Level Communication Frequency and Data
Point Source
Priority Visit
Frequency Update contact
information
Locational / Monitoring Information
Water Quality Impact Preparation
High Once per
year Check bi-annually
Identify outfalls, detailed location
maps, locate sampling points
Conduct estimates of water quality impacts from releases
under various extreme scenarios (loss of treatment, full release),
estimate and verify time of travel, monitor disease rates
Medium High Every 2 years Annually
Identify outfalls, detailed location
maps, locate sampling points
Conduct estimates of water quality impacts from releases
under various extreme scenarios (loss of treatment, full release),
estimate and verify time of travel, monitor disease rates
Medium Every 3 years Every 3 years Identify outfalls
only
Conduct estimates using a predetermined worst case
screening accident scenario, refine distance estimates,
develop low flow and high flow TOT estimates
Low Every permit
cycle Every permit
cycle Identify outfalls
only
Conduct estimates using a predetermined worst case
screening accident scenario, refine distance estimates,
develop low flow and high flow TOT estimates
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5.3. Emergency Response Tools
The only major emergency response tool that Wilmington employs currently is the Turbidity Early Warning System that was described earlier. However, there are several other emergency response tools available to Wilmington.
The simplest tool available is the Chester County Health Department’s phone notification chain. This phone chain provides simple, but relatively rapid notification of accidents that result in releases to the streams in Chester County.
A more complex tool that could be available is the Delaware Valley Early Warning System (DVEWS). The DVEWS is an integrated web and phone based system that is operated on the Schuylkill and Delaware Rivers in Pennsylvania and New Jersey. Water suppliers, county, state, and federal agencies are involved in this system and provide information to it. The system would need expansion to include the Brandywine Creek Watershed that may require some costs to Wilmington. In addition, annual membership costs are required for the operation and maintenance of the system that water suppliers contribute.
At the minimum, it is recommended that Wilmington contacts Chester County to get enrolled in the phone notification chain program. Also, Wilmington should investigate the costs and benefits to participation in the Delaware Valley Early Warning System.
5.4. Contingency Planning
5.4.1. Contaminant Response Plans for Accidental or Deliberate Release into Source of Potable Waters
Wilmington can withdraw from two different locations on the Brandywine (Wills Pump Station and Brandywine Race) as well as provide all its water needs for a limited period of time from the Hoopes Reservoir. The standard response to any water quality event in the Brandywine Creek is to switch to the Hoopes Reservoir. In the event the Hoopes Reservoir is not available due to contamination or a major failure of the conveyance system to or from Hoopes to the water facilities, Wilmington has a number of interconnections with other water suppliers and can draw from the raw water basin at Porter for a period of time until the Hoopes system is available. In addition, there is significant finished water storage available in the event the water treatment facilities are shut down. It is assumed that in most cases any contamination event on the Brandywine Creek may pass by the Wilmington intake before raw and finished water storage would run out. Another option during a water quality event is to request a release from one of the upstream reservoirs operated by PA or Chester County in order to dilute any pollution during dry weather periods. Wilmington should update its protocol for communication for an upstream reservoir release. An analysis of the critical failure elements of the Hoopes system, potential redundancies, and repair times in the event of a dual failure is recommended.
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5.5. Alternative Supplies
Wilmington can withdraw from two different locations on the Brandywine (Wills Pump Station and Brandywine Race) as well as provide all its water needs for a limited period of time from the Hoopes Reservoir. Therefore, Wilmington does not plan to locate alternate supplies in the short or long term future. If for some reason the Brandywine and Hoopes sources were not going to be available to Wilmington for some unforeseen reason, studies and plans to use the desalinization of the Delaware River would need to be considered.
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6. Section 6 – Regulatory Compliance & AWWA Certification
6.1. LT2ESWTR & Stage 2 DBPR
The Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and the Stage 2 Disinfection By-Products Rule (Stage 2 DBPR) are the two major regulations that their drinking water compliance can be impacted by source water quality. The LT2ESWTR is the direct connection of a treatment requirement based on raw water concentrations of Cryptosporidium. The Stage 1 DBPR has a direct requirement for Total Organic Carbon (TOC) removal based on source water concentration. The Stage 2 DBPR has an indirect treatment requirement based on the finished water concentration of disinfection by products such as total trihalomethanes TTHMs) and haloacetic acids (HAAs). TTHMs and HAAs are formed as a result of the organic matter in the water reacting to chlorine or disinfection processes. These requirements force the utility to use less disinfection or move disinfection further back in the treatment train such that less DBPs are formed during water treatment. This complicated balancing act of increasing treatment and potentially disinfection to reduce microbial risks from Cryptosporidium while reducing disinfection by products is called the Microbial Disinfection By Product (MDBP) challenge to water suppliers.
The purpose of the LT2ESWTR is to reduce disease incidence associated with Cryptosporidium and other pathogenic microorganisms in drinking water. The rule applies to all public water systems that use surface water or ground water that is under the direct influence of surface water. The rule was to bolster existing regulations and provide a higher level of protection of drinking water supplies by:
Targeting additional Cryptosporidium treatment requirements to higher risk systems
Requiring provisions to reduce risks from uncovered finished water storage facilities
Providing provisions to ensure that systems maintain microbial protection as they take steps to reduce the formation of disinfection byproducts
Under the LT2ESWTR, systems will monitor their water sources to determine treatment requirements. This monitoring includes an initial two years of monthly sampling for Cryptosporidium. Filtered water systems will be classified in one of four treatment categories (bins) based on their monitoring results (See Tables 6-1 to 6-3). Currently Wilmington’s Monitoring data indicates that it will be located in Bin 1 for the Porter Filtration Plant, but the data suggests the average is near the Bin 1 upper limit. The Brandywine Filtration Plant is near Bin 1 limit as well, but is installing membrane filtration systems to meet the LT2ESWTR requirements. Systems classified in higher treatment bins
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must provide 90 to 99.7 percent (1.0 to 2.5-log) additional treatment for Cryptosporidium. Systems will select from a wide range of treatment and management strategies in the "microbial toolbox" to meet their additional treatment requirements. Some of these potential “toolbox” options are the use of improved filtration, increased disinfection, or a watershed control program (source water protection program) (see Table 6-2).
Table 6-1 – Source Water Concentration and Additional Treatment Requirements of the Long Term 2 Enhanced Surface Water Treatment Rule
Source Water Concentration (oocysts/L)
Bin classification
Additional treatment requirement
< 0.075 1 No additional treatment
0.075 to < 1.0 2 1 - log treatment
1.0 to < 3.0 3 2 - log treatment
3.0 or greater 4 3 - log treatment
Table 6-2 – Toolbox Options and Cryptosporidium Treatment Credit of the Long Term 2 Enhanced Surface Water Treatment Rule
Toolbox option Cryptosporidium treatment credit
Watershed Control Program 0.5 log credit
Alternative source/intake management No prescribed credit, based on
monitoring
presedimentation basin with coagulation 0.5 log credit, basins must achieve
monthly mean reduction of 0.5 log or greater in turbidity
two stage lime softening 0.5 log credit
bank filtration 0.5 log credit
combined filter performance 0.5 log credit, CFE < 0.15 NTU at
least 95% of monthly measurements
individual filter performance 0.5 log credit (additive to CFE), IFE <
0.15 NTU at least 95% of monthly measurements per filter
demonstration of performance based on demonstration
bags and cartridge filters up to 2 log credit
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Toolbox option Cryptosporidium treatment credit
membrane filtration based on demonstration
second stage filtration 0.5 log credit
slow sand filters 2.5 log credit
chlorine dioxide based on CT and CT table
ozone based on CT and CT table
UV based on UV dose and UV does table
The Stage 1 DBP Rule regulates water systems that use surface water or ground water under the direct influence of surface water and use conventional filtration treatment. These systems are required to remove specified percentages of organic materials, measured as total organic carbon (TOC) that may react with disinfectants to form DBPs (See Table 6-3). Removal will be achieved through a treatment technique (enhanced coagulation or enhanced softening) unless a system meets alternative criteria. As discussed in Section 2, Wilmington’s TOC and Alkalinity have changing trends that could affect this required removal rate making it potentially more difficult and costly to achieve over the long term.
Table 6-3 - Required Removal of Total Organic Carbon by Enhanced Coagulation and Enhanced Softening for Subpart H Systems Using Conventional Treatment1
Source Water TOC (mg/L) Source Water Alkalinity (mg/L as CaCO3)
0-60 >60-120 >1202
>2.0-4.0 35.0% 25.0% 15.0%
>4.0-8.0 45.0% 35.0% 25.0%
>8.0 50.0% 40.0% 30.0%
1Systems meeting at least one of the alternative compliance criteria in the rule are not required to meet the
removals in this table. 2Systems practicing softening must meet the TOC removal requirements in the last column to the right.
The Stage 2 DBP rule builds upon earlier rules that addressed disinfection byproducts to improve drinking water quality and provide additional public health protection from disinfection byproducts. This final rule strengthens public health protection for customers by tightening compliance monitoring requirements for two groups of DBPs, trihalomethanes (TTHM) and haloacetic acids (HAA5). The rule targets systems with the greatest risk and will reduce potential health risks related to DBP exposure and provide more equitable public health protection.
Under the Stage 2 DBP rule, systems will conduct an evaluation of their distribution
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systems, known as an Initial Distribution System Evaluation (IDSE), to identify the locations with high disinfection byproduct concentrations. These locations will then be used by the systems as the sampling sites for Stage 2 DBP rule compliance monitoring.
Compliance with the maximum contaminant levels for two groups of disinfection byproducts (TTHM and HAA5) will be calculated for each monitoring location in the distribution system. This approach, referred to as the locational running annual average (LRAA), differs from current requirements, which determine compliance by calculating the running annual average of samples from all monitoring locations across the system.
The Stage 2 DBP rule also requires each system to determine if they have exceeded an operational evaluation level, which is identified using their compliance monitoring results. The operational evaluation level provides an early warning of possible future MCL violations, which allows the system to take proactive steps to remain in compliance. A system that exceeds an operational evaluation level is required to review their operational practices and submit a report to their state that identifies actions that may be taken to mitigate future high DBP levels, particularly those that may jeopardize their compliance with the DBP MCLs.
Wilmington is currently conducting its ISDE monitoring and results are not available to evaluate its potential compliance and linkage to source water quality at this time.
6.2. Watershed Control Program Certification Evaluation
The LT2ESWTR allows water suppliers to implement a number of items if additional Cryptosporidium treatment is required. If Wilmington chooses to apply for the Watershed Control Program Credit (though it is not necessary at this time). The Watershed Control Program Credit is a credit offered by implementing a watershed protection program. In order to be eligible to receive this credit initially, it must perform the following steps:
Notify the State of the intent to develop a new or continue an existing watershed control program for Cryptosporidium treatment credit no later than two years prior to the date Wilmington must comply with additional Cryptosporidium treatment requirements under today’s rule.
Submit a proposed watershed control plan to the State for approval no later than one year prior to the date the Wilmington must comply with additional Cryptosporidium treatment requirements under today’s rule. The watershed control plan must contain these elements:
1. The designation of an ‘‘area of influence’’ in the watershed, which is defined as the area outside of which the likelihood of Cryptosporidium contamination affecting the treatment plant intake is not significant;
2. The identification of both potential and actual sources of Cryptosporidium
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contamination, including a qualitative assessment of the relative impact of these contamination sources on water quality at the treatment plant intake;
3. An analysis of control measures that could mitigate the sources of Cryptosporidium contamination, including the relative effectiveness of control measures in reducing Cryptosporidium loading to the source water and their feasibility; and
4. A statement of goals and specific actions the Wilmington will undertake to reduce source water Cryptosporidium levels, including a description of how the actions will contribute to specific goals, watershed partners and their roles, resource requirements and commitments, and a schedule for plan implementation.
Based on the previous elements of the Source Water Protection Plan, it is believed that Wilmington has and will accomplish each of the four requirements outlined above in order to receive the credit if it so chooses to apply for it. If the State approves the watershed control plan for Cryptosporidium treatment credit, Wilmington must perform the following steps to be eligible to maintain the credit:
Submit an annual watershed control program status report to the State no later than a date specified by the State. The status report must describe the following: (1) how Wilmington is implementing the approved watershed control plan; (2) the adequacy of the plan to meet its goals; (3) how Wilmington is addressing any shortcomings in plan implementation; and (4) any significant changes that have occurred in the watershed since the last watershed sanitary survey.
Notify the State prior to making any significant changes to the approved watershed control plan. If any change is likely to reduce the planned level of source water protection, Wilmington must include in this notification a statement of actions that will be taken to mitigate this effect.
Perform a watershed sanitary survey no less frequently than Wilmington must undergo a sanitary survey under 40 CFR 142.16(b)(3)(i), which is every three to five years, and submit the survey report to the State for approval. The State may require a PWS to perform a watershed sanitary survey at an earlier date if the State determines that significant changes may have occurred in the watershed since the previous sanitary survey. A person approved by the State must conduct the watershed sanitary survey and the survey must meet applicable State guidelines. The watershed sanitary survey must encompass the area of influence as identified in the State-approved watershed control plan, assess the implementation of actions to reduce source water Cryptosporidium levels, and identify any significant new sources of Cryptosporidium.
Wilmington is eligible to receive Cryptosporidium treatment credit under today’s rule for preexisting watershed control programs (e.g., programs in place at the time of rule promulgation). To be eligible for credit, such programs must meet the requirements stated in this section and the watershed control plan must address future actions that will further reduce source water Cryptosporidium levels.
If the State determines that Wilmington is not implementing the approved watershed
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control plan (i.e., Wilmington is not carrying out the actions on the schedule in the approved plan), the State may revoke the Cryptosporidium treatment credit for the watershed control program. Failure by Wilmington to demonstrate treatment credit at least equal to its Cryptosporidium treatment requirement under today’s rule due to such a revocation of credit is a treatment technique violation. The violation lasts until the State determines that Wilmington is implementing an approved watershed control plan or is otherwise achieving the required level of Cryptosporidium treatment credit.
Wilmington must make the approved watershed control plan, annual status reports, and watershed sanitary surveys available to the public upon request. These documents must be in a plain language style and include criteria by which to evaluate the success of the program in achieving plan goals. If approved by the State, Wilmington may withhold portions of these documents based on security considerations.
The required elements for a watershed control plan are the minimum necessary for a program that will be effective in reducing levels of Cryptosporidium and other pathogens in a treatment plant intake. These elements include defining the area of the watershed where contamination can affect the intake water quality, identifying sources of contamination within this area, evaluating control measures to reduce contamination, and developing an action plan to implement specific control measures.
Wilmington will need to leverage other Federal, State, and local programs in developing the elements of their watershed control plans. In 2002, EPA launched the Watershed Initiative (67 FR 36172, May 23, 2002) (USEPA 2002b), which will provide grants to support watershed-based approaches to preventing, reducing, and eliminating water pollution. In addition, EPA recently promulgated regulations for Concentrated Animal Feeding Operations that will limit discharges that contribute microbial pathogens to watersheds.
Since Wilmington does not control the watersheds of their sources of supply. Their watershed control plans should involve partnerships with watershed landowners and government agencies that have authority over activities in the watershed that may contribute Cryptosporidium to the water supply. Stakeholders that control activities that could contribute to Cryptosporidium contamination include municipal government and private operators of wastewater treatment plants, livestock farmers and persons who spread manure, individuals with failing septic systems, logging operations, and other government and commercial organizations.
After a State approves a watershed control plan for Wilmington and initially awards 0.5-log Cryptosporidium treatment credit, Wilmington must submit a watershed control program status report to the State each year. These reports are required for States to exercise oversight and ensure that Wilmington implement the approved watershed control plan. They also provide a mechanism for Wilmington to work with the States to address any shortcomings or necessary modifications in watershed control plans that are identified after plan approval.
In addition, Wilmington must undergo watershed sanitary surveys every three to five years by a State-approved party. These surveys will provide information to PWSs and States regarding significant changes in the watershed that may warrant modification of the approved watershed control plan. Also, they allow for an assessment of watershed control
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plan implementation.
The proposed rule required watershed sanitary surveys annually, but EPA has reduced the frequency to every three to five years in today’s final rule. This frequency is consistent with existing requirements for sanitary surveys. If significant changes in the watershed do occur, Wilmington must identify these changes in their annual program status reports. In addition, States have the authority to require that a watershed sanitary survey be conducted at an earlier date if the State determines that significant changes may have occurred in the watershed since the previous survey. The current rule gives States authority to revoke Cryptosporidium treatment credit for a watershed control program at any point if a State determines that Wilmington is not implementing the approved watershed control plan.
Wilmington should be eligible to receive Cryptosporidium treatment credit for watershed control programs that are in place prior to the treatment compliance date such as its easement efforts with the Brandywine Conservancy. The same requirements for watershed control program treatment credit apply regardless of whether the program is new or existing at the time Wilmington submits the watershed control plan for approval. In the case of existing programs, the watershed control plan must list future activities Wilmington will undertake that will reduce source water contamination.
The Toolbox Guidance Manual lists programmatic resources and guidance available to assist Wilmington in building partnerships and implementing watershed protection activities. It also incorporates information on the effectiveness of different control measures to reduce Cryptosporidium levels and provides case studies of watershed control programs.
In addition to this guidance and other technical resources, EPA provides funding for watershed and source water protection through the Drinking Water State Revolving Fund (DWSRF) and Clean Water State Revolving Fund (DWSRF). Under the DWSRF program, States may fund source water protection activities by PWSs, including watershed management and pathogen source reduction plans. CWSRF funds can be used for agricultural best management practices to reduce pathogen loading in receiving waters and for the replacement of failing septic systems.
6.3. AWWA SWP Accreditation Evaluation
The City of Wilmington can choose to develop the Source Water Protection Program in order to achieve accreditation by AWWA. In order to accomplish accreditation it will need to have a program and plan that includes the following six major elements:
Vision of the program
Source water characterization
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Goals
Action Plan
Implementation of the action plan
Provides evaluation and revision
The vision of the program must do the following:
Recognize that source water protection as one of the steps in the multiple barrier approach
Ensure safety and quality of the drinking water
Commit or intention to commit sufficient resources to accomplish the vision
Identify key stakeholders to develop a vision statement
In Wilmington’s current plan in Section 7, the goals of the program currently acknowledge most of these elements. However, a formal vision will need to be written for the program. A draft vision for the program could potentially include the following language:
Source Water Protection is a key step in the multiple barrier approach to drinking water for the City of Wilmington, and therefore, the City of Wilmington in order to ensure the future safety and quality of the drinking water supply for future generations will commit the appropriate resources to implementing its source water protection plan. The City of Wilmington will implement the source water protection program and plan with its many upstream stakeholders.
Management and key leaders in the City of Wilmington potentially including City Council may need to formally acknowledge and endorse this vision and plan.
A source water characterization must include the following elements:
Delineation of the source water area
Water quality and quantity data analysis
Contaminant sources and landuse including evaluation of controls of those sources
Compliance with regulatory requirements
Security issues – describe response of personnel in case of security incident
Emergency preparedness and response
Stakeholders
Section 2 of the Source Water Protection Plan includes all of these elements in considerable
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detail. This area of accreditation is covered well.
The accreditation program also requires goals to be defined. These goals are different than the goals in the Source Water Protection plan because they are very specific. Therefore the objectives in Section 7 would be more similar to the goals required for accreditation. Goals for accreditation would need to provide the following elements:
Address specific problems or issues
Be expressed in terms that can be measured
Meet or surpass existing or pending regulations
Since all the goals and objectives in the plan in Section 7 include 46 indicators to measure progress, it is believed the elements of the current plan could be easily rearranged into a set of specific programmatic goals.
The action plan required for accreditation is similar to the implementation tasks discussed in Section 7. An action plan is focused on identifying actions to mitigate water quality in the watershed. The action plan must include the following:
Identify specific projects, programs, and activities for mitigation
Prioritization of projects and sources
Identify resources needed for mitigation
Identify problems and obstacles
Implements controls to monitor progress
The implementation plan in section 7 appears to include these elements.
The program implementation is the way the source water program develops, promotes, or implements a combination of voluntary or regulatory programs/practices. This element includes:
Watershed planning
Land conservation
Landuse controls
Currently Wilmington is implementing all three of the previous elements so program implementation would most likely be considered satisfactory. The remaining steps in accreditation include the provisions to review and evaluate the program and verification of implementation or improvements. Wilmington’s program includes indicators to monitor and evaluate success of the plan as well as verification. Since the program is new conscious and documented requirements to conduct review, evaluation, and verification, at the project and program level need to be developed.
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7. Section 7 - Brandywine Watershed Source Water Protection Objectives, Progress Indicators, & Implementation Activities
Based on the information provided in the previous sections, a series of goals, objectives, indicators, and implementation tasks (short and long term) were developed for the City of Wilmington’s water supply. Overall, 4 major goals, 29 major objectives, 78 implementation tasks covering various time periods, and 46 potential progress indicators were created as part of the implementation plan for Wilmington to initiate and sustain a Source Water Protection Program that can lead to successful achievement of its goals.
These goals, objectives, and tasks are not to be considered a separate effort from the overall efforts of stakeholders in the watershed, but a specific prioritization of activities related to protection of the City of Wilmington’s drinking water source that can be integrated with upstream efforts. The following items significantly complement the general goals and recommendations of the Chester County Compendium, the Brandywine Action Plan, the Delaware Pollution Control Strategy, and the TMDLs for the Brandywine Creek Watershed. Therefore, synergy of common SWP activities with activities from the other stakeholders and plans is encouraged and recommended during implementation of this program.
7.1. SWP Goals
Goals are meant to be general descriptions of the ultimate achievement of an endeavor. Therefore, the goals for Wilmington’s source water protection efforts are provided to give a vision of what is desired in the long term. As shown the four major goals are:
1. Develop and operate a nationally recognized sustainable source water protection program with in-house expertise and save capital and operating dollars;
2. Preserve or improve the current water quality and quantity of the Brandywine Creek and Hoopes Reservoir for Wilmington’s water supply;
3. Improve early warning and emergency communications;
4. Establish relationships and participate in efforts with stakeholders that shape and influence policy, regulation, resources, and initiatives in the watershed
Have a strong voice in activities that influence water policy in the region
Develop key partnerships with stakeholders that can impact the future of Wilmington’s water supply
Leverage the efforts and resources of other stakeholders to address priority water quality issues
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7.2. SWP Objectives
Under each goal there are a number of objectives serving as the stepping stones for achievement. Objectives are clear actions having measurable outcomes. The objectives are provided in accordance with the intended goal below.
1. Goal - Develop and operate a nationally recognized sustainable source water protection program with in-house expertise and save capital and operating dollars.
Hire, train, and support an in-house dedicated staff member (or staff member with Source Water Protection (SWP) in its job description) to attend stakeholder and community meetings, conduct studies, manage contracts, coordinate and monitor efforts, and participate in various internal, stakeholder, and regulator activities in the watershed related to Source Water Protection. Provide expert assistance and resources to the in-house staff as needed. This staff member is also responsible for the pursuit of external funding to support the City’s SWP efforts.
Develop a program that obtains accreditation from American Water Works Association (AWWA) by meeting the requirements of the AWWA Source Water Protection Standard
Achieve regional and national recognition for its source water protection efforts.
2. Goal - Preserve or improve the current water quality and quantity of the Brandywine Creek and Hoopes Reservoir for Wilmington’s water supply.
Partner with other watershed stakeholders, such as Chester County Conservation District, Brandywine Conservancy, Brandywine Valley Association, Chester Water Resources Authority, United States Geological Survey, Water Resources Association of the University of Delaware and others to:
Develop and implement conservation and nutrient management plans and streambank fencing on all dairy farms along first and second order streams in the Honey Brook region of the West Branch of the Brandywine Creek watershed.
Preserve as much farmland as possible in riparian buffer areas along first and second order streams by 2070. With specific milestones for 2020.
Develop an initiative to preserve remaining forested riparian buffer lands along first and second order streams between 2030 and 2070.
Partner with upstream communities to identify which areas need to develop and implement land use ordinances similar to the New Castle County Water Resource Protection Area (WRPA) ordinance that reduce impervious cover in critical riparian areas. Support efforts to extend riparian land protections
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similar to the NCC WRPA ordinances upstream along all tributaries of the Brandywine Creek.
Support the development of storm water utilities with impervious cover parcel based billing systems in the Brandywine Creek Watershed to reduce stormwater runoff and improve long term groundwater recharge.
Support efforts by upstream communities to improve and enforce stormwater and riparian ordinances.
Encourage upstream communities to reduce road salt application through the use of brining to reduce chloride impacts and reduce road salting costs while maintaining proper road safety in the Brandywine Creek Watershed.
Partner with upstream communities to reduce pathogen and emerging contaminants in upstream wastewater discharges.
Conclusively identify the dominant upstream sources of Cryptosporidium and bacteria in the watershed.
Identify contributing sources of trace organics from human or animal activity during wet and dry weather periods in the Brandywine Creek Watershed.
Conduct studies using thermal sensing equipment and flyovers to identify sewage infiltration to the Brandywine River and its tributaries.
3. Goal - Improve early warning of spills or water quality or quantity changes in stream and emergency communications
Participate in the Chester County Health Department (CCHD) Notification System and set up protocol for notification of events by CCHD.
Develop a working group of water suppliers and emergency responders to discuss and improve emergency notification/communication and response to events that pose a risk to water quality and water treatment.
Develop a Standard Operating Procedure (SOP) listing the locations, methods, equipment, and personnel needed to sample the Brandywine Creek and Hoopes Reservoir in response to a serious water quality event.
Conduct a study of current in-stream monitoring network and ways it can be enhanced for improved warning and response while providing useful long term source water protection data.
Conduct a study using a time of travel and dilution/concentration model of various contaminant types (conservative, non-conservative, oils) spilled into the Brandywine Creek to improve intake pumping and monitoring responses. Link
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the spill model to stream monitoring network for real time projections.
4. Goal - Establish relationships and participate in efforts with stakeholders that shape and influence policy, regulation, resources, and initiatives in the watershed
Continue to actively participate in Christina Clean Water Partnership.
Continue to participate in watershed events such as annual clean ups with various organizations.
Support enhanced funding initiatives to sustain water quality improvements to the Brandywine Creek Watershed.
Develop a water supplier initiative for the Brandywine Creek.
Join the Source Water Collaborative with EPA.
Develop funding agreements with upstream stakeholder and watershed organizations to leverage specific efforts.
Support and/or participate in grant applications with partnering organizations to support projects that improve or protect water quality.
7.3. Implementation Activities
The various activities that are necessary for implementation can be divided into the following types of major implementation activity areas:
Agricultural Mitigation
Agricultural Preservation
Forest Preservation
Riparian Buffer and Forest Reforestation
Wastewater Discharge Management and Emergency Response Preparation and Communication
Stormwater Runoff Mitigation
Stakeholder Partnerships and Outreach & Public Education
Monitoring & Technical Studies
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Hoopes Reservoir Protection
Financial Support and Analysis
These activities can have short term and long term elements as well as localized and watershed wide components. The most pertinent activities include the following:
7.3.1. Agricultural Mitigation
Top Priority Areas: Honey Brook Township clusters 1, 2, and 3 and immediately upstream of Wilmington’s intake in New Castle County Delaware (see Figure 7-1)
Secondary Priority Areas: W. Branch of Brandywine Creek
Key Activity: Streambank fencing to reduce livestock access and runoff impacts. Nutrient management and conservation plans at livestock and dairy farms.
Major Program Milestone for 2020: 100 farms with streambank fencing and management plans and/or 20 miles of streambank fencing. Completion of streambank fencing in Honey Brook cluster 1 or 3. (see Figure 7-1)
Wilmington’s Role/Responsibility: Technical support, minor/limited match funding support, monitoring support, grant support
Amount of Financial Assistance Necessary from Other Sources: $450,000 per year from Federal, State, Local, and private sources. Usually the greatest challenge is locating a local match to the USDA funding sources. In most cases the farmer cannot provide the entire required federal match, but should be required to have some match in the projects.
Benefits to Wilmington’s Water Supply: Prevents and reduces pathogens such as Cryptosporidium, sediment, livestock pharmaceuticals, ammonia, nitrate, and phosphorus. A study by AWWA and the Trust for Public Lands of water supplies suggested that for every 4 percent increase in raw water turbidity, treatment costs increase 1 percent. (Trust for Public Lands, 2004)
Partners: Chester County Conservation District, Brandywine Conservancy, Honey Brook Township, New Castle County Conservation District, Delaware Nutrient Management Commission, USDA NRCS, DNREC, PADCNR, PADEP, Trout Unlimited, Ducks Unlimited.
There are 327.7 miles of agricultural lands along first order streams in the Brandywine Creek Watershed. However, agricultural mitigation efforts need to focus primarily on the Honey Brook Township area of the West Branch Brandywine Creek, where 1,700 acres of land and 25 miles of stream are in need of protection in this priority area. Within this larger area, approximately 7 farms covering 450 acres are of the highest priority because of cattle access to the stream. In order to protect the Honey Brook clusters, roughly 10% or 170
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acres or 2.5 miles of streambank would need mitigation annually. It is estimated that $217,000 per mile of streambank with fencing with a total cost of over 5 million dollars is ultimately required to protect the Honey Brook township clusters.
In the New Castle County section of the main stem of the Brandywine Creek, activities need to focus on projects to get cows and livestock out of the tributaries to the main stem Brandywine Creek from the City’s intake upstream to the Delaware border. Roughly 3 miles of tributaries and stream along agricultural properties in Delaware upstream of Wilmington’s intake, requires some level of mitigation or protection. It is estimated that 92 acres of pasture areas also need examination for potential mitigation. An immediate priority to implement streambank fencing in areas where livestock are accessing the stream in Delaware and a long term effort to protect the remaining areas in Delaware.
Throughout the watershed the most important mitigation activities include streambank fencing and implementation of conservation and nutrient management plans at dairy and livestock farms. It is estimated that $450,000 per year should be dedicated to these efforts with a total of 8.9 million dollars to implement 20 miles of streambank fencing and mitigation work at 100 farms over the next 10 to 20 years.
The following are specific priority agricultural activities that should be considered for implementation immediately:
Meet with landowners and partners to support a project to get cows out of the stream as soon as possible at farms near Smiths Bridge Road.
Meet with New Castle County Conservation District to discuss initial approaches for farm protection projects for remaining farms along tributaries and the main stem.
Meet with Chester County Conservation District to identify leveraging opportunities and to identify farms in the Honey Brook priority area that are ready for streambank fencing and protection projects.
Facilitate efforts for funding and implementation of Honey Brook Clusters 1 & 3. (see Figure 7-1)
Facilitate and match funding efforts for funding of additional no-till farm equipment for Amish farming. Meet with Chester County Conservation District to determine mechanisms of how to support this effort.
Officially recognize the recent preservation of the Harsh Farm property.
Develop a process for Wilmington to officially recognize award winning farms upstream.
Identify and prioritize dairy farms with and without conservation and nutrient management plans in the Honey Brook area.
Expand upon the agricultural preservation priorities in the Upper East Branch to Honey Brook township and the West Branch of the Brandywine Creek.
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Identify, scope, and support application for PA American Water Works Service Company Watershed grant and PADEP Growing Greener grant project to support an agricultural mitigation priority project in the Honey Brook clusters.
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Figure 7-1 – Priority Agricultural Mitigation Areas on West Branch Brandywine Creek in Honey Brook
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7.3.2. Agricultural Preservation
Top Priority Areas: Honey Brook Township clusters 1, 2, and 3 and immediately upstream of Wilmington’s intake in New Castle County Delaware. (see Figure 7-2)
Secondary Priority Areas: W. Branch of Brandywine Creek
Key Activity: Preserve farmland, with primary emphasis on parcels with first order streams or adjacent to streams.
Major Program Milestone for 2020: 5,500 acres preserved.
Wilmington’s Role/Responsibility: Technical support, minor/limited match funding support, monitoring support, grant support
Amount of Financial Assistance Necessary from Other Sources: $5 million per year from Federal, State, Local, and private sources.
Benefits to Wilmington’s Water Supply: Prevents and reduces pathogens such as Cryptosporidium, sediment, ammonia, nitrate, and phosphorus as well as contaminants related to urbanization of farmland from urban stormwater. A study by AWWA and the Trust for Public Lands of water supplies suggested that for every 4 percent increase in raw water turbidity, treatment costs increase 1 percent (Trust for Public Lands, 2004).
Partners: Chester County Conservation District, Brandywine Conservancy, Honey Brook Township, New Castle County Conservation District, Delaware Nutrient Management Commission, USDA NRCS, DNREC, PADCNR, PADEP, Trout Unlimited, Ducks Unlimited.
Properly managed and preserved farmland can support significant riparian buffers and prevents the addition of urban/suburban stormwater challenges due to development. Agricultural Preservation efforts should focus on preserving as much farmland as possible in riparian buffer areas along first and second order streams by 2100. In order to preserve roughly 60% of the existing farmland in the watershed (or 69 square miles of land) requires roughly $5 million per year for 100 years (preserving 550 acres/yr). The Honey Brook area on the West Branch, Buck and Doe Run, and the Upper East Branch prime agricultural parcels should be the primary area of initial focus.
In New Castle County it is estimated that 1,778 acres of farmland needs to be assessed for its preservation status. It is estimated that 2700 acres of farms are adjacent to 33 miles of stream within Honey Brook Township. These lands represent initial priorities for preservation during the initial 5 to 10 year period in conjunction with other key preservation areas identified in the West Branch.
The following are specific priority agricultural activities that should be considered for implementation immediately:
Identify preserved farms in Honey Brook Township for comparison to priority cluster areas
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Identify preserved or eased farms in New Castle County for comparison to remaining farm areas.
Identify mechanisms/frameworks for agricultural preservation
Identify ways to enhance/accelerate current agricultural preservation efforts
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Figure 7-2 – Priority Agricultural Preservation Areas on West Branch Brandywine Creek in Honey Brook
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7.3.3. Forest Preservation
Top Priority Areas: Perkins Run and Indian Run clusters (See Figure 7-3)
Secondary Priority Areas: Marsh Creek and Upper East Branch
Key Needed Activity: Preserve forested lands especially along first order tributaries via conservation easements and other approaches.
Major Program Milestone for 2020: 20 miles/10,000 acres (2 miles/1,000 acres per year). The rate is nearly twice the annual rate of loss of forested land due to development in the watershed.
Wilmington’s Role/Responsibility: Technical support, minor/limited match funding support, monitoring support, grant support.
Amount of Financial Assistance Necessary from Other Sources: $800,000 per year from various public and private funding sources.
Benefits to Wilmington’s Water Supply: Prevents pathogens such as Cryptosporidium, road salts, and increased flows due to development. Forests reduce/filter sediment, ammonia, nitrate, and phosphorus. Treatment costs increase as forested lands drop below 40% of the watershed. For every 10 percent increase in forest cover in the source area, treatment and chemical costs decreased approximately 20 percent, up to about 60 percent forest cover as reported in a study by AWWA and the Trust for Public Lands (Trust for Public Lands, 2004). Partners: Brandywine Conservancy, USDA Forest Service, DNREC, PADCNR, PADEP, Natural Lands Trust, Trust for Public Lands, William Penn Foundation, Conservation Fund, Pennsylvania Environment Coalition, Delaware Horticultural Society, Delaware Nature Society.
Forest Preservation efforts need to focus the short term efforts on the Perkins Run and Indian Run cluster areas along first order streams. Within the Delaware portion of the Brandywine Watershed there is approximately 1,000 acres of riparian forested lands that need to be examined for preservation.
Preservation of priority areas will require about $800,000 per year and protect 2 miles of stream bank and 1,000 acres per year. Watershed wide approximately 75 square miles need to be preserved at a cost of approximately 48 million dollars. Some potential partners for this effort include the Pennsylvania Department of Conservation of Natural Resources, Chester County Water Resources Authority, New Castle County, Delaware Natural Resources Environmental Conservation, Chester County, Brandywine Conservancy, Brandywine Valley Association, Natural Lands Trust, Trust for Public Lands, William Penn Foundation, Conservation Fund, Pennsylvania Environment Coalition, Delaware Horticultural Society, Delaware Nature Society.
The following are specific priority forest preservation activities that should be considered
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for implementation immediately:
Continue the Brandywine Conservancy headwaters preservation, track leveraging and benefits
Initiate, facilitate, and support efforts to preserve forested riparian buffer areas in Indian Creek and Perkins Run along the Upper East Branch
Lead and facilitate the initial efforts for a larger effort to prioritize and preserve forested buffer areas watershed wide.
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Figure 7-3 – Priority Forest Preservation Areas of Perkins Run and Indian Run on East Branch Brandywine Creek
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7.3.4. Riparian Buffer & Forest Reforestation
Top Priority Areas: First order riparian lands and headwaters areas
Secondary Priority Areas: Watershed Wide
Key Needed Activity: Reforest lands along first order tributaries and along the riparian corridor in general.
Major Program Milestone for 2020: 582 acres per year. The rate is roughly equal to the annual rate of loss of forested land due to development in the watershed.
Wilmington’s Role/Responsibility: Technical support, minor/limited match funding support, monitoring support, grant support.
Amount of Financial Assistance Necessary from Other Sources: $500,000 per year from various public and private funding sources.
Benefits to Wilmington’s Water Supply: Prevents pathogens such as Cryptosporidium, road salts, increased flows due to development. Forests reduce/filter sediment, ammonia, nitrate, and phosphorus. Treatment costs increase as forested lands drop below 40% of the watershed. For every 10 percent increase in forest cover in the source area, treatment and chemical costs decreased approximately 20 percent, up to about 60 percent forest cover in a study by AWWA and the Trust for Public Lands (Trust for Public Lands, 2004).
Partners: Brandywine Conservancy, USDA Forest Service, DNREC, PADCNR, PADEP, Natural Lands Trust, Trust for Public Lands, William Penn Foundation, Conservation Fund, Pennsylvania Environment Coalition, Delaware Horticultural Society, Delaware Nature Society.
Riparian Buffer Restoration efforts require a detailed watershed wide analysis and groundtruthing of riparian buffer gaps to be completed. In lieu of complete information watershed wide, a teamed grant application to fund a study for the watershed wide analysis should be completed. On a parallel track, initial efforts by the City of Wilmington should be piloted within the tributaries to the main stem in New Castle County where detailed information is available and effectiveness can be monitored. Detailed information provided by the Brandywine Conservancy suggests the lands in the Wilson Run tributary and the agricultural lands near Smiths Bridge Road in Ramsey Run, Beaver Run, and an unnamed tributary are the greatest priority (See Figure 7-4). This work involves a relatively limited number of stakeholders and property owners. The City of Wilmington should immediately meet with these stakeholders to discuss ways to improve riparian buffer protection in these areas. Given, the garden lands and the nearby golf course are large landowners with potential for matching interests, it is recommended that efforts start with those two locations first.
In addition, a watershed wide initiative for reforestation should be developed that is linked to potential funding sources via carbon credits, carbon sequestration, or carbon cap and
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trade programs for energy suppliers and businesses. There are many large industries in the watershed and region that may be interested in this approach. However a framework needs to be developed that regulators will accept and a champion to administer and implement the program will need to be identified.
Some initial steps to starting this effort include the following:
Develop programs to reforest key riparian parcels upstream of COW intake in New Castle County along the main stem and first order streams.
Develop funding agreements with Brandywine Conservancy and Brandywine Valley Watershed association to leverage specific reforestation efforts in first order streams or headwaters areas.
Develop regional initiative with BCC, BVA, water suppliers, and Chester County to reforest remaining forested riparian buffer lands along first and second order streams by 2100.
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Figure 7-4
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7.3.5. Wastewater Discharge Enhancements and Emergency Response Preparation and Communication
Top Priority Activities: Visit high priority point sources. Increase notification of emergency and water quality events upstream that have potential to impact water supply.
Key Needed Activity: Monitor upstream discharger and point source facility activities. Improve communication of potential water quality events with upstream facilities.
Major Program Milestone for 2010: Visit all top priority point source facilities and establish lines of communication/notification.
Wilmington’s Role/Responsibility: Facilitator, technical
Amount of Financial Assistance Necessary from Other Sources: Staff time
Benefits to Wilmington’s Water Supply: Improved response and awareness of upstream accidents and activities that could result in acute water quality events or long term water quality changes that will impact Wilmington’s intakes
Partners: PADEP, DNREC, Chester County Health Department, New Castle County, City of Coatesville, City of Downingtown, upstream water suppliers
Point source management and emergency response efforts should focus on the following priority activities:
Support upgrades to advanced tertiary and UV treatment to mitigate pathogens
Enhance communications with Health Departments regarding upstream occurrence of waterborne or gastrointestinal disease greater than would otherwise be expected in a particular time and place.
Increase communication for improved responses in case of accident
Convene a workshop with PADEP, CCHD, DNREC, and pertinent health agencies for future warning to water suppliers about Cryptosporidiosis outbreaks and monitoring of upstream wastewater discharges during events
Enroll in Chester County upstream notification - get calls from phone chain
Receive calls from Marsh Creek Lake during releases – contact Park Manager
Develop internal protocols to respond to calls from upstream dischargers, water
suppliers, etc.
Visit high point sources – ongoing effort that requires training staff and developing
outreach / communication information for upstream facilities.
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Develop appropriate phone and contact information list for high priority point sources
immediately.
Establish protocol for watershed surveys and data collection
Emergency response efforts should focus on the following priority activities:
Visit high ranked facilities upstream, update internal information, and exchange emergency contact information
Visit all major upstream discharges upstream – exchange contact information
Contact Chester County Health and get added to phone chain for spills
Investigate enrolling in Delaware Valley Early Warning System
Improve notification about reservoir releases upstream (CWRA)
Enhance the turbidity early warning system to include conductivity warnings for road salt application
Contact emergency responders in NCC upstream of COW intake and drinking water to communicate water supply sensitivity to wash down and accidents.
Design and install water supply educational roadway signs at key locations in the watershed & Hoopes Reservoir.
Develop an SOP listing the locations, methods, equipment, and personnel needed to sample the Brandywine Creek and Hoopes Reservoir in response to a serious water quality event.
7.3.6. Stormwater Runoff Mitigation
Top Priority Activities: Incentives, implementation, and enforcement of stormwater management ordinances for all development. Enhancement of upstream MS4 programs.
Key Needed Activity: Consistent and complementary regulations, standards, protections, buffers, steep slope requirements, implementation, and enforcement of stormwater ordinances and regulations throughout the entire Brandywine Creek Watershed.
Major Program Milestone for 2020: Implementation and enforcement of consistent and complementary stormwater regulations and ordinances watershed wide
Wilmington’s Role/Responsibility: Facilitator, technical
Amount of Financial Assistance Necessary from Other Sources: Staff time
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Benefits to Wilmington’s Water Supply: Partners: PADEP, DNREC, Chester County Water Resources Authority, New Castle County
Stormwater management should focus on the following priority activities:
Identify opportunities to match SWP efforts with ACT 167 and Chester County Ordinance Initiatives (Landscapes, Watersheds, etc.)
Support riparian buffer ordinance protections upstream in DE and PA
Monitor TMDL activities related to upstream MS4 permits
Provide support and assistance during the creation of upstream stormwater utilities
Support the adoption of LEEDs requirements for new construction in upstream communities
Develop and implement a pilot project with DELDOT and COW for using brining to reduce road salt application near intake
Reconvene a Public Works working group at Wilmington about road salt and brining to identify key areas for brining and resources/barriers to implementing brining in these areas.
Develop a pilot program with DNREC, DELDOT, and PENNDOT to identify critical areas to reduce road salt application through the use of brining to reduce chloride impacts and reduce road salting costs while maintaining proper road safety in the Brandywine Creek Watershed
Integrate and enhance the aspects of the PADEP and Chester County stormwater regulations with the steep slope and erosion prone slope related aspects of the New Castle County Water Resource Protection Area ordinance watershed wide.
7.3.7. Stakeholder Partnerships and Public Education & Outreach
Key Needed Activity: Staff involvement and attendance at key stakeholder events and forums. Routine communication and engagement of stakeholders.
Major Program Milestone for 2020: Known by all stakeholders as a key partner in the watershed and stakeholders consider the Brandywine Creek’s top priority is water supply protection.
Wilmington’s Role/Responsibility: Facilitator, technical
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Amount of Financial Assistance Necessary from Other Sources: Staff time
Benefits to Wilmington’s Water Supply: Potential opportunities to leverage other resources and efforts to achieve a source water goal Partners: Members of the Christina Basin Coalition
Stakeholder partnership efforts should focus on the following priority activities:
Implementation of the SWP Ordinance
Participate in the Phase 7 scope of work development for the EPA Watersheds Grant
Support efforts for workshops to enroll upstream golf courses in Audubon Certification Program and the continued participation of golf courses.
Arrange SWP Program in order to submit application for AWWA Accreditation.
Set up water supplier meeting to discuss SWP Plan, support for watershed protection, and coordination of efforts, set up protocols for calls and communication during events
Evaluate the need and develop, if appropriate, funding agreements with partnering organizations in the watershed, which will leverage specific preservation and restoration efforts.
Participate in watershed events such as annual clean ups with various organizations.
Initiate and facilitate discussions to develop a combined water supplier funding initiative for the Brandywine Creek
Conduct an annual SWP workshop on the Brandywine
Obtain approval and endorsement of the Wilmington Source Water Protection Plan by key stakeholders, PADEP, DNREC, and EPA Region 3
Design and install water supply educational roadway signs at key locations in the Brandywine Creek watershed (near the intakes) & Hoopes reservoir areas.
7.3.8. Monitoring & Technical Studies
Key Needed Activity: Monitoring to identify upstream sources of pollution for prioritization and mitigation.
Major Program Milestone for 2020: Identification of major pathogen sources upstream for mitigation. Development of an early warning monitoring system for water quality
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events.
Wilmington’s Role/Responsibility: Facilitator, technical
Amount of Financial Assistance Necessary from Other Sources: Staff time and laboratory resources
Benefits to Wilmington’s Water Supply: Awareness, understanding, and knowledge of water quality trends, phenomena, and events through monitoring can allow for predictive and preventative actions. Partners: USGS, water suppliers, DNREC, PADEP, EPA, local/regional universities
Monitoring efforts should focus on the following priority activities:
Pathogen source tracking study plan
Add conductivity to early warning system upstream where needed
Participate in emerging contaminant monitoring as needed
Conduct a study using a time of travel and dilution/concentration model of various contaminant types (conservative, non-conservative, oils) spilled into the Brandywine Creek to improve intake pumping and monitoring responses. Eventually link the spill model to stream monitoring network for real time projections.
Enhance the turbidity early warning system to include conductivity warnings for road salt application
Explore, plan, & conduct microbial source tracking studies to identify dominant sources of Cryptosporidium and pathogens in watershed
Conduct a study of current in-stream monitoring network and ways it can be enhanced for improved warning and response while providing useful long term source water protection data.
Share data with PA and DE stakeholders and regulatory agencies for watershed wide water quality trending
Assess the risk and management options for forest fires at Hoopes Reservoir
7.3.9. Hoopes Reservoir Protection
Key Needed Activity: Reforestation of deforested areas. Forest management plan.
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Major Program Milestone for 2020: Reforestation of deforested areas along the reservoir
Wilmington’s Role/Responsibility: Facilitator, technical
Amount of Financial Assistance Necessary from Other Sources: Staff time
Benefits to Wilmington’s Water Supply: Sustained long term high quality water supply Partners: Mt. Cuba Center, emergency responders, neighboring property owners
Hoopes Reservoir management should focus on the following priority activities:
Conduct forest survey of Hoopes
Improve markers of COW Property boundaries
Create an enforcement process for deforestation
Educate adjacent property owners
Develop a stakeholder group (Friends of Hoopes Reservoir)
Reforest the Hoopes Area
Identify areas for critical land acquisition/easements around Hoopes if any remain
Initiate communication and education of emergency responders near Hoopes and put up appropriate signage at key road crossings.
Assess the risk and management options for forest fires at Hoopes Reservoir
Develop a volunteer surveillance and notification program with stakeholders near the reservoir to observe forest health, trespassing, and unusual occurrences in and around the reservoir.
7.3.10. Financial Support and Analysis
Key Needed Activity: Identification and acquisition of long term sustainable funding sources to implement efforts in the protection plan
Major Program Milestone for 2020: Sustainable funding framework created.
Wilmington’s Role/Responsibility: Facilitator, technical
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Amount of Financial Assistance Necessary from Other Sources: To be determined
Benefits to Wilmington’s Water Supply: Long term funding will lead to consistent implementation of water supply protection goals. Without funding programs in the watershed will not be able to mitigate current and future pollution sources and the water quality will degrade in the Brandywine Creek.
Partners: All
Support the efforts of the Christina Basin Coalition to develop a long term framework for sustainable funding.
Determine the cost and benefit of water supply protection specific to the City of Wilmington in terms of avoided long term treatment, operating, capital costs, and triple bottom line findings.
7.4. Recommended Immediate Priority Activities
It may be difficult to determine where to start implementing the Source Water Protection Plan with the limited resources available since there are such a large number of activities recommended in the plan. The following activities are recommended for initial implementation.
Implement the SWP Ordinance
Facilitate and support streambank fencing at farms near Smith’s Bridge Road
Continue to leverage preservation efforts with watershed partners such as Brandywine Conservancy
Partner with Brandywine Conservancy on larger efforts for forest preservation and reforestation
Implement several streambank fencing projects with CCCD and BVA and evaluate benefit to Wilmington.
Estimate the cost benefit and long term impacts of deforestation of the watershed on long term water quality and treatment costs
Enhance current protocols for Hoopes Reservoir usage due to Brandywine Creek water quality
Develop and establish protocols to respond to upstream notifications
Familiarize staff with watershed and key upstream dischargers and information on watershed
Continue to build partnerships with upstream stakeholders
Present the SWP Plan to stakeholders and educate the value to key City staff and officials
Obtain resolution approving the SWP Plan by City Council
Initiate monitoring for the Microbial Source Tracking Project
Identify and leverage opportunities through the Christina Coalition
Initiate road salt reduction discussions and develop a pilot project
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Secure nomination for the EPA Region 3 SWP Award
Compete for the AWWA Exemplary SWP Program National Award
7.5. Cost Estimates
In Table 7-1 and 7-2 the following assumptions were used to estimate some of the costs presented.
Farm mitigation costs were estimated using the following values:
Stream bank crossings required every 1500 LF of stream, $3,000 per crossing
Stream bank fencing = $1.75 / Linear foot of stream
General barnyard and manure storage improvements = $83,000 per farm
Nutrient management plan preparation = $20 per acre
Farm and Forested Land Preservation costs were estimated using the following:
Based on average parcel costs provided by Brandywine Conservancy every preserved farm or forested parcel (in most cases the parcel includes both land use types) was assumed to cost roughly $10,000.
The historical rate of land preservation in the watershed is approximately 1,200 acres per year. Using this rate over 40 years produces 48,000 acres or roughly 75 square miles of forested cover preserved or about 23% of the watershed. Over 111 square miles of land exists inside first order drainage areas according to estimates in the Chester County Compendium (CCWRA, 2001).
7.6. Progress Indicators
A number of potential indicators can be used to measure the progress and performance of the various major objectives and goals for the City of Wilmington’s SWP Program. Some metrics are qualitative while some are quantitative. Many of the indicators are provided below and summarized in Table 7-2.
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Table 7-2 Progress Indicators for Wilmington’s SWP Plan
Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
1 All preservation forested land preserved
in watershed acres 1,000 48,000 3 100 50+ years
1.1 All preservation
forested land preserved in riparian areas along all first order streams miles 8 107 7 100 40 years
1.1.1 All preservation
forested riparian land preserved in key
headwater streams of Perkins Run, Indian
Run, and Marsh Creek miles 2 20 10 100 10 years
1.1.2 All preservation
forested riparian areas along the main stem
Brandywine from COW's intake upstream to the E. and W. Branch
split - PA section acres 50 500 10 100 10 years
1.1.3 All preservation
forested riparian areas along the main stem
Brandywine from COW's intake upstream
- DE/NCC section acres/miles 0.4 / 9 4.0 / 90 10 100 10 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
1.1.4 All preservation
first order stream wooded parcels in
riparian corridors for preservation/easements
in the Pocopson creek subbasin watersheds to
complement agricultural mitigation
clusters miles 0.5 5 10 100 10 years
1.2 All preservation
Hoopes Reservoir lands reforestation of critical
drainage areas acres NA NA NA 100 5 years
2 All agricultural
stream miles preserved in agricultural lands
along first order streams miles 3 126.2 2 100 40 years
2.1 All agricultural
miles of streambank fencing along first order
streams miles 10 327.7 3 100 40 years
2.2 All agricultural acres preserved in
Honey Brook clusters acres 170 1700 10 100 10 years
2.1.1 All agricultural
miles of streambank fencing in Honey Brook
clusters miles 2.5 25 10 100 10 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
2.3 All agricultural
streambank fencing of the tributaries to the
main stem Brandywine from COW's intake upstream to the DE
border acres/miles 3 / 0.5 16 / 3 18 100 6 years
2.4 All agricultural
streambank fencing in the Pocopson creek
subbasin watersheds miles 1 10 10 100 10 years
3 All agricultural area of agricultural land
preserved acres 550 44,160 2 100 40 years
3.1 All agricultural
area of agricultural land with nutrient
management plans acres 1,000 40,000 2 100 40 years
3.2 All agricultural
area of agricultural land with conservation management plans acres 1,000 40,000 2 100 40 years
4 All agricultural
# of dairy farms with nutrient management
plans # farms 10 all 10 100 40 years
5 All agricultural
# of dairy farms with conservation
management plans # farms 10 all 10 100 40 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
6 All agricultural
# of farms in watershed with nutrient
management plans # farms 20 all 10 100 40 years
7 All agricultural
# of farms in watershed with conservation management plans # farms 20 all 10 100 40 years
8 All agricultural
# of no-till devices and usage by Amish in West
Branch # farms 2 5 40 100 5 years
9 pathogens
agricultural /
wastewater
2 year average concentration of
Cryptosporidium at Wilmington intake oocysts/L TBD
< 0.075 oocysts/L 5 25 5 years
10 emerging
contaminants wastewater
Number of emerging contaminants detected
above the ppt level from human sources # 1 < 10 NA NA 10 years
11 emerging
contaminants agricultural
Number of emerging contaminants detected
above the ppt level from agricultural sources # 1 < 10 NA NA 10 years
12 sodium & chloride
roads/ highways
maximum sodium and chloride concentrations
at the Wilmington intake during winter mg/L < SMCL < SMCL TBD TBD 10 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
13 sodium & chloride
roads/ highways
winter loads of sodium and chloride at the Wilmington intake mg /day TBD decrease TBD TBD 10 years
14 sodium & chloride
roads/ highways
Annual road application of road salts (tons) along Brandywine
sensitive roads tons/yr TBD decrease TBD TBD 10 years
15 sodium & chloride
roads/ highways
miles of sensitive/critical roads in the Brandywine with
brining road salt application protocols miles TBD all TBD TBD 10 years
16 algae /
nutrients all
concentrations of geosmin and MIB at the Wilmington intake and
other water intakes # events > 10
ppt 2
always below 10
ppt NA NA 10 years
17 turbidity stormwater
Average annual sediment load and
compliance with the sediment TMDL % compliance TBD 100% NA NA 40 years
18 All stormwater
Reduction in the number of impaired stream miles in the Brandywine Creek
watershed miles TBD TBD 2 100 40 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
19 pathogens all
# of locations meeting bacteria standards in
the Brandywine Creek watershed
Number of Pathogens TBD 100% NA NA 40 years
20 pathogens all Compliance with the
bacteria TMDL % compliance TBD 100% NA NA 40 years
21 emergency response
spills/ accidents
frequency/# of water quality events requiring
water intake closure Number of
Spills/Accidents 0 never NA NA 40 years
22 emergency response
spills/ accidents
# of notifications by CCHD or upstream
users/responders about potential WQ events
(more is good) Number of
Spills/Accidents 10 all NA 100 3 years
23a All partnerships
Funding for agricultural mitigation activities in
the watershed $ 1
million 40 million 3 100 40 years
23b All partnerships
Funding for agricultural preservation activities
in watershed $ $ 5
million 400
million 1.25 100 80 years
24 All partnerships
Funding for forest preservation activities
in the watershed $ $ 8
million $ 48
million 3 100 40 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
25 All partnerships
Funding for riparian buffer reforestation in
the watershed $ $
250,000 $
10,000,000 3 100 40 years
26 All partnerships
Funding for stormwater management in the
watershed $ TBD
300 million /
yr TBD 100 40 years
27
turbidity/ pathogens/
DBP stormwater
% of townships that have similar or better ordinance elements to
the NCC WRPA ordinance % 3% all 3 100 40 years
28
turbidity/ pathogens/
DBP stormwater
% of townships with parcel based impervious
cover stormwater billing % 3% all 3 100 40 years
29 All partnerships
Involvement in the Christina
Coalition/Partnership and presence on CC
committees # meetings/
calls attended NA all NA NA 40 years
30 All SWP
Program In-house ability for SWP # staff
1 full time staff
1 full time staff NA NA 1 year
31 All SWP
Program In-house ability for SWP $ allocated 150,000 $
6,000,000 NA NA 40 years
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Goal Level WQ priority Activity
Area Measurement Unit
Annual Goal
(units)
Ultimate Goal
(units) Annual
Goal (%) Ultimate Goal (%) Timeframe
32 All preservation # of golf courses with Audubon Certification # golf courses 2 12 17 100 6 years
33 All education
Public awareness of Brandywine as drinking
water supply % of customers
surveyed 5% 100% 5 100 20 years
34 All restoration
Riparian buffer reforestation &
restoration in New Castle County # acres 30 300 10 100 10 years
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WORKS CITED
American Forests. Setting Tree Canopy Goals.
http://www.americanforests.org/resources/urbanforests/treedeficit.php (accessed 10 12, 2009).
Anderson, K. and R. Lonsdorf, 2008. Brandywine Conservancy Preliminary Riparian Buffer Gap
Analysis. Personal Communication, 12/08/08.
Barnes, M., T. Albert, W. Lilja, R. Barten. Forests, Water and People: Drinking water supply and forest
lands in the Northeast and Midwest United States. Newtown Square, PA: United States Department of
Agriculture Forest Service, 2009.
Bowers, J., Greig, D., and Kauffman, G. Phase III Report: Christina Basin Water Quality Management
Strategy. Management Plan, Chester County: Chester County, 1999.
Bowers, J., Greig, D., and Kauffman, G. Phase I and II Report: Christina Basin Water Quality
Management Strategy. Management Plan, Chester County: Chester County, 1998.
Brandywine Conservancy, 2004. Upper East Branch Brandywine Creek River Conservation Plan. Report to the PA Department Conservation and Natural Resources.
Brandywine Valley Association & Chester County Water Resources Authority, . Brandywine Creek
Watershed Conservation Plan. Conservation Plan, Chester County: Brandywine Valley Association,
2003.
Brandywine Valley Association. State of the Watershed Report. Annual Report, West Chester:
Brandywine Valley Association, 2005.
Brandywine Valley Association. State of the Watershed Report. Annual Report, West Chester:
Brandywine Valley Association, 1998.
Brandywine Valley Association. State of the Watershed Report. Annual Report, West Chester:
Brandywine Valley Association, 1997.
Brandywine Valley Association. State of The Watershed Report. Annual Report, West Chester:
Brandywine Valley Association, 1999.
Chester County Board of Commissioners and Chester County Water Resources Authority. Watersheds –
An Integrated Water Resources Management Plan for Chester County, Pennsylvania and Its Watersheds.
Management Plan, West Chester: Chester County Water Resources Authority, 2002.
Chester County Water Resources Authority. Chester County Compendium. Edited by Dan Greig, Gerald
Kaufman Jan Bowers. West Chester: Chester County, 2001.
City of Wilmington Source Water Protection Plan
Page 294
Chester County Water Resources Authority. Water Resources Compendium – Part 1: Technical Report of
Assessment of 21 Watersheds Originating in Chester County, Pennsylvania. Water Resource Report,
West Chester: Chester County Water Resources Authority, 2001.
Chester County Water Resources Authority, Chester County Planning Commission, Camp Dresser and
McKee, Gaadt Perspectives, LLC,. Brandywine Creek Watershed Action Plan. Component of the Chester
County Compendium, West Chester: Chester County Water Resources Authority, 2002.
Cinotto, P.J. Occurrence of fecal-indicator bacteria and protocols for identification of fecal-contamination
sources in selected reaches of the West Branch Brandywine Creek, Chester County, Pennsylvania. U.S.
Geological Survey Scientific Investigations Report 2005-5039, New Cumberland: U.S. Geological
Survey, 2005, 91.
Corozzi, M. and G. Kauffman. Christina Basin Pollution Control Strategy. Management Plan, Newark:
University of Delaware, 2007.
Crockett, C.S. "The Role of Wastewater Treatment in Protecting Water Supplies Against Emerging
Pathogens." Water Environment Research 79, no. 3 (March 2007): 221-232.
Dudley, N. & Stolton, S. Running Pure. WWF/World Bank Alliance for Forest Conservation and
Sustainable Use, Gland, Switzerland: WWF, 2003.
Interlandi S.J. and C. S. Crockett "Recent Water Quality Trends In The Schuylkill River, Pennsylvania,
USA: A Preliminary Assessment of The Relative Influences of Climate, River Discharge, and Suburban
Development." Water Research 37, no. 8 (2003): 1737-1748.
Greig, D., J. Bowers, and G. Kauffman. A Christina Clean Water Strategy. Management Plan, West
Chester: Chester County, 1998.
Jackson, John. Understanding Stream Conditions: Lessons from an 11 Year Study of Macroinvertebrates
In Eastern Pennsylvania's Schuylkill River Watershed, With A Focus on Exceptional Value and High
Quality Streams. Research, Avondale, PA: Stroud Water Research Center, 2009.
Kauffman, G., Wozniak, S. L., and Vonck, K. J. A Watershed Restoration Action Strategy (WRAS) for
the Delaware Portion of the Christina Basin "A Clean Water Strategy to Protect and Restore the
Watersheds of the Brandywine, Red Clay, and White Clay Creeks and Christina River in Delaware.
Management Plan, Newark: University of Delaware, 2003.
Kauffman, Gerald J., Martha B. Corrozi, and Kevin J. Vonck. "Imperviousness: A Performance Measure
of a Delaware Water Resource Protection Area Ordinance." Journal of the American Water Resources
Association 42, no. 3 (2006): 603-615.
Koerkle, E. H., and Lisa A. Senior. Simulation Of Streamflow And Water Quality In The Brandywine
Creek Subbasin Of The Christina River Basin, Pennsylvania And Delaware, 1994-98. Water-Resources
Investigations Report 02-4279, New Cumberland: Department of Interior, United State Geological
Survey, 2002.
City of Wilmington Source Water Protection Plan
Page 295
Low, D.J., D. J. (Trust for Public Lands 2004)Hippe, and D. Yannacci. Geohydrology of Southeastern
Pennsylvania. Water-Resources Investigations Report 00-4166, New Cumberland: Department of
Interior, United States Geological Survey, 2002.
Pennsylvania Department of Environmental Protection. Watershed Restoration Action Strategy (WRAS)
State Water Plan Subbasins 03H and 03I Christina River Basin (Brandywine Creek and White Clay Creek
Watersheds) Chester, Delaware and Lancaster Counties. Status Report, Harrisburg: Pennsylvania
Department of Environmental Protection, 2003.
Pyke, Grantley W., William C. Becker, Richard Head, and Charles R. O’Melia. Impacts of Major Point
and Non-Point Sources on Raw Water Treatability. Research Report, Denver, CO: AWWARF, 2003.
Reif, A. G. Assessment of Stream Conditions and Trends in Biological and Water-Chemistry Data From
Selected Streams in Chester County, Pennsylvania, 1981-97. U.S. Geological Survey Water-Resources
Investigations Report 02-4242, New Cumberland: U.S. Geological Survey, 2002, 77.
Reif, A. G. Assessment of Water Chemistry, Habitat, and Benthic Macroinvertebrates at Selected Stream-
Quality Monitoring Sites in Chester County, Pennsylvania, 1998-2000. U.S. Geological Survey Open-File
Report 03-499, New Cumberland: U.S. Geological Survey, 2004, 84.
Reif, D. Water Quality Trends in Chester County, PA. Water Resources Investigation Report, New
Cumberland: Department of Interior, U.S. Geological Survey, 2002.
Self J.R. and R.M. Waskom. Nitrates in Drinking Water. Colorado State University
http://www.ext.colostate.edu/PUBS/crops/00517.html. 2009
Schreffler, C. L. Low-Flow Statistics of Selected Streams in Chester County, Pennsylvania. U.S.
Geological Survey Water-Resources Investigations Report 98-4117, Lemoyne: U.S. Geological Survey,
1998, 43.
Schreffler, Curtis L. USGS Low-Flow Statistics of Selected Streams in Chester County, Pennsylvania.
Water Resources Investigation Report 98-4117, New Cumberland: Department of Interior, United States
Geological Survey, 1998.
Town, D. A. Historical Trends and Concentrations of Fecal Coliform Bacteria in the Brandywine Creek
Basin, Chester County, Pennsylvania. U.S. Geological Survey Water-Resources Investigations Report 01-
4026, New Cumberland: U.S. Geological Survey, 2001, 46.
Trust for Public Lands. Protecting the Source. Environmental Study, San Francisco, CA: Trust for Public Lands and American Water Works Assocation, 2004.
U.S. Environmental Protection Agency, Region III. Bacteria and Sediment TMDL Development for
Christina River Basin, Pennsylvania-Delaware-Maryland. TMDL report, Philadelphia: U.S.
Environmental Protection Agency, Region III, 2005.
U.S. Environmental Protection Agency, Region III. Christina River Basin High-Flow TMDLs for
City of Wilmington Source Water Protection Plan
Page 296
Nutrients, Low Dissolved Oxygen, and Bacteria: Data Report (Draft). TMDL draft report, Philadelphia:
U.S Environmental Protection Agency, Region III, 2004.
U.S. Environmental Protection Agency, Region III. "Hydrodynamic and water quality model of Christina
River Basin." TMDL model report, Philadelphia, 2000.
U.S. Environmental Protection Agency, Region III. Total Maximum Daily Loads for Bacteria and
Sediment in the Christina River Basin, Pennsylvania, Delaware, and Maryland. Section 2 Source
Assessment. Philadelphia: U.S. Environmental Protection Agency, Region III, 2006, 2-1 to 2-17.
Union of Concerned Scientists. "Climate Change in Pennsylvania Impacts and Solutions for the Keystone
State." Union of Concerned Scientists. October 1, 2008.
http://www.ucsusa.org/assets/documents/global_warming/Climate-Change-in-Pennsylvania_Impacts-and-
Solutions.pdf (accessed October 10, 2008).
University of Delaware. Source Water Assessment of the City of Wilmington, Delaware Public Water
Supply Intake Located on the Brandywine Creek. Water supply assessment, College of Human Services,
Education, & Public Policy Institute, Water Resources Agency, Dover: DNREC, 2002.
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Appendix A
Point Source Inventory Ranking
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TABLE A-1 - Rank of Potentially Significant Point Sources Upstream of Wilmington’s Intake
NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
PA0026531 Downingtown Area Regional Authority
PCS/NPDES 8.63 7.134 20.1 9.63 High
PA0026859 Coatesville City Authority PCS/NPDES 5.16 3.85 27.5 6.16 High
6437 DUPONT EXPERIMENTAL STATION SFUND & TRI 4.35 5.60 High
7107 E I Dupont Experimental Station HW_Gen & TRI 3.39 4.64 High
PA0026018 West Chester Borough MUA/Taylor Run
PCS/NPDES 3.42 1.8 15.1 4.42 High
569614 ZEKES HC SHEELER AST 2.45 20000 HO 3.95 High
508704 REILLY & SONS AST 2.36 20000 HO 3.86 High
508704 REILLY & SONS AST 2.36 20000 DIESL 3.86 High
569614 ZEKES HC SHEELER AST 2.13 12000 HO 3.63 High
569614 ZEKES HC SHEELER AST 1.97 8000 KERO 3.47 High
569614 ZEKES HC SHEELER AST 1.87 20000 HO 3.37 High
517410 JC HAYES AST 1.83 20000 HO 3.33 High
517410 JC HAYES AST 1.83 20000 KERO 3.33 High
4161 Brandywine Raceway Assoc Inc UST 1.55 3.05 High
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
4400 HAGLEY MUSEUM & LIBRARY UST 1.55 3.05 High
593737 PETROCON AST 1.55 4000 KERO 3.05 High
DE0021768 Winterthur Museum PCS/NPDES 2.03 0.025 0.0 3.03 High
PA0043982 Broad Run Sewer Co. PCS/NPDES 1.94 0.4 18.2 2.94 High
PA0053449 Birmingham Twp. STP PCS/NPDES 1.93 0.15 8.9 2.93 High
6644 BANCROFT MILLS SFUND 2.42 2.92 High
593737 PETROCON AST 1.41 550 GAS 2.91 High
PA0054917 Uwchlan Twp. Municipal Authority PCS/NPDES 1.89 0.475 23.3 2.89 High
PA0055476 Birmingham TSA/Ridings at Chadds Ford
PCS/NPDES 1.88 0.04 6.4 2.88 High
511023 TEXACO 100250 UST 1.37 12000 GAS 2.87 High
PA0024473 Parkersburg Borough Authority WWTP
PCS/NPDES 1.86 0.7 33.5 2.86 High
PA0055484 Keating, Herbert & Elizabeth PCS/NPDES 1.84 0.0005 6.4 2.84 High
PA0055085 Winslow, Nancy PCS/NPDES 1.84 0.0005 6.4 2.84 High
PA0030848 Unionville - Chadds Ford Elem. School
PCS/NPDES 1.83 0.0063 7.0 2.83 High
PA0057011 Thornbury Twp./Bridlewood Farms STP
PCS/NPDES 1.82 0.0773 10.2 2.82 High
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
1542 CHESTER CNTY AIRPORT AST 1.32 15000 AVGAS 2.82 High
1542 CHESTER CNTY AIRPORT AST 1.32 15000 JET 2.82 High
4830 Carpenter Estates UST 1.32 2.82 High
3682 Dupont Winterthur Museum UST 1.32 2.82 High
5086 Estate of Neil H Keough J UST 1.32 2.82 High
5040 LANPHEAR Property ALBERT UST 1.32 2.82 High
4838 St Joseph On the Brandywine UST 1.32 2.82 High
4198 Wilmington Country Club UST 1.32 2.82 High
PA0036200 Radley Run Mews PCS/NPDES 1.81 0.032 8.9 2.81 Medium High
PA0031097 Radley Run C. C. PCS/NPDES 1.79 0.017 8.9 2.79 Medium High
511023 TEXACO 100250 UST 1.29 10000 DIESL 2.79 Medium High
511023 TEXACO 100250 UST 1.29 10000 GAS 2.79 Medium High
569163 LONGWOOD GARDENS AST 1.26 6000 DIESL 2.76 Medium High
PA0056120 Schindler PCS/NPDES 1.76 0.0005 9.5 2.76 Medium High
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
4986 A FELIX Dupont UST 1.24 2.74 Medium High
4666 Alapoccas Maintenance Base UST 1.24 2.74 Medium High
4374 Alexis I Dupont Middle School UST 1.24 2.74 Medium High
4674 Bayard Sharp Estate UST 1.24 2.74 Medium High
3604 Brandywine Commons UST 1.24 2.74 Medium High
3838 Concord Pike Gulf UST 1.24 2.74 Medium High
4744 Craven Property UST 1.24 2.74 Medium High
3611 Dupont Experimental Station UST 1.24 2.74 Medium High
4865 HANK BLACKS FOREIGN CAR UST 1.24 2.74 Medium High
5076 HENRY Property John UST 1.24 2.74 Medium High
6089 Laird Property UST 1.24 2.74 Medium High
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
4280 LINCOLN TOWERS UST 1.24 2.74 Medium High
5077 Norwood Property UST 1.24 2.74 Medium High
4114 Porter Filter Plant UST 1.24 2.74 Medium High
6229 REED Property UST 1.24 2.74 Medium High
4557 ROSS HOLDEN UST 1.24 2.74 Medium High
6135 Stonesgate Retirement Community UST 1.24 2.74 Medium High
6105 THORNTON Property UST 1.24 2.74 Medium High
4620 WIDENER University UST 1.24 2.74 Medium High
4386 Wilmington Piece Dye Company UST 1.24 2.74 Medium High
4878 WOODLAWN TRUSTEES Inc UST 1.24 2.74 Medium High
PA0056171 McGlaughlin, Jeffrey PCS/NPDES 1.73 0.0005 10.8 2.73 Medium High
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
PA0036897 South Coatesville Borough PCS/NPDES 1.72 0.39 26.9 2.72 Medium High
511023 TEXACO 100250 UST 1.21 8000 GAS 2.71 Medium High
515503 THORNDALE EXXON UST 1.21 10000 GAS 2.71 Medium High
573143 SUNOCO 0013 6804 UST 1.20 8000 GAS 2.70 Medium High
569511 SUNOCO 0318 3209 UST 1.19 12000 GAS 2.69 Medium High
PA0044776 NW Chester Co. Municipal Authority PCS/NPDES 1.68 0.6 36.8 2.68 Medium
1542 CHESTER CNTY AIRPORT AST 1.17 15000 JET 2.67 Medium
3940 Ace Citgo UST 1.16 2.66 Medium
3863 Avenue Gulf MICHAEL FUSCO UST 1.16 2.66 Medium
4920 BARBARA PRUITT EI DUPON UST 1.16 2.66 Medium
4752 BIDERMAN GOLF COURSE UST 1.16 2.66 Medium
5143 Brandywine Creek State Park UST 1.16 2.66 Medium
4418 City of Wilmington Parks UST 1.16 2.66 Medium
3826 Conoco Inc #08008 UST 1.16 2.66 Medium
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
3537 Delaware Auto Service UST 1.16 2.66 Medium
4273 Dupont BARLEY MILLRECORD MGMT
UST 1.16 2.66 Medium
4043 Dupont Country CLUB UST 1.16 2.66 Medium
4903 Estate OF PS Dupont III UST 1.16 2.66 Medium
3867 Exxon/JAMES L GARDNER UST 1.16 2.66 Medium
3753 FLINT Robert UST 1.16 2.66 Medium
4921 Jacques Amblard Property UST 1.16 2.66 Medium
4434 John Wanamaker Dept Store UST 1.16 2.66 Medium
4111 Kennett Pike Sub Station UST 1.16 2.66 Medium
4925 LINCOLN CAMERA Shop UST 1.16 2.66 Medium
4754 M&E Auto Service Center UST 1.16 2.66 Medium
4684 Medical Center of Delaware UST 1.16 2.66 Medium
3734 Shell Station Ponti UST 1.16 2.66 Medium
4148 STRAND MILLAS UST 1.16 2.66 Medium
3951 Sunoco 0004/6771 UST 1.16 2.66 Medium
3957 Sunoco 0004/7019 UST 1.16 2.66 Medium
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
4248 Texaco Service Station 140450075 UST 1.16 2.66 Medium
4737 WICK Property UST 1.16 2.66 Medium
4112 Wills Pump Station UST 1.16 2.66 Medium
569163 LONGWOOD GARDENS AST 1.16 3000 GAS 2.66 Medium
515090 EXTON EXXON UST 1.16 15000 GAS 2.66 Medium
PA0029912 Embreeville Hospital PCS/NPDES 1.65 0.1 18.2 2.65 Medium
515503 THORNDALE EXXON UST 1.13 8000 GAS 2.63 Medium
PA0057282 Jonathan & Susan Pope PCS/NPDES 1.62 0.0005 15.1 2.62 Medium
569511 SUNOCO 0318 3209 UST 1.11 10000 GAS 2.61 Medium
515503 THORNDALE EXXON UST 1.09 12000 GAS 2.59 Medium
PA0053937 Johnson Ralph & Gayla PCS/NPDES 1.58 0.0005 17.0 2.58 Medium
PA0056618 O'Cornwell, David & Jeanette PCS/NPDES 1.58 0.0005 17.0 2.58 Medium
569163 LONGWOOD GARDENS AST 1.08 2000 DIESL 2.58 Medium
569163 LONGWOOD GARDENS AST 1.08 2000 GAS 2.58 Medium
508704 REILLY & SONS UST 1.07 10000 DIESL 2.57 Medium
508704 REILLY & SONS UST 1.07 10000 GAS 2.57 Medium
515090 EXTON EXXON UST 1.04 12000 DIESL 2.54 Medium
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
PA0053996 Redmond, Michael PCS/NPDES 1.53 0.0005 18.8 2.53 Medium
PA0012815 Sunoco Products PCS/NPDES 1.52 1.028 20.1 2.52 Medium
515240 GETTY 69205 UST 0.99 10000 GAS 2.49 Medium
569163 LONGWOOD GARDENS AST 0.98 1500 DIESL 2.48 Medium
270237 CHESTER CNTY PRISON AST 0.97 2000 HZSUB 2.47 Medium
507814 FH 38291 UST 0.96 10000 GAS 2.46 Medium
507814 FH 38291 UST 0.96 10000 KERO 2.46 Medium
250910 ALCOA FLEXIBLE PKG DOWNINGTOWN PLT
AST 0.96 5000 OTHER 2.46 Medium
1542 CHESTER CNTY AIRPORT UST 0.94 12000 JET 2.44 Medium
PA0052663 Knight's Bridge Co/Villages at Painters
PCS/NPDES 1.43 0.09 6.4 2.43 Medium
4394 1401 Condominium Apartments UST 0.93 2.43 Medium
6124 1506 DelawareAvenue Corp UST 0.93 2.43 Medium
3904 Amoco #711 UST 0.93 2.43 Medium
5000 BAGELS & DONUTS UST 0.93 2.43 Medium
6024 BENEFICIAL NATIONAL Bank UST 0.93 2.43 Medium
6033 Brandywine REALTY & DEV Inc UST 0.93 2.43 Medium
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
5137 Casscells Property UST 0.93 2.43 Medium
3805 CERTIFIED Auto Service UST 0.93 2.43 Medium
4604 CHRIST Church UST 0.93 2.43 Medium
5042 CONCORD CLEANERS UST 0.93 2.43 Medium
6125 CYNWYD Corp UST 0.93 2.43 Medium
3575 Delaware Motor Sales Inc UST 0.93 2.43 Medium
3566 J & M LITTERELLE Inc UST 0.93 2.43 Medium
4790 KELLERS DRY CLEANERS UST 0.93 2.43 Medium
4803 LEXUS OF Wilmington UST 0.93 2.43 Medium
4931 NAPA Auto Parts UST 0.93 2.43 Medium
6351 Pawliczek Property UST 0.93 2.43 Medium
4874 SHARP Estate UST 0.93 2.43 Medium
5146 Sienna Hall UST 0.93 2.43 Medium
4587 ST ANNS Church UST 0.93 2.43 Medium
4526 St Francis Hospital UST 0.93 2.43 Medium
4919 STOCKWell ANTIQUARIES UST 0.93 2.43 Medium
4422 STRATFORD Apartments UST 0.93 2.43 Medium
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
4085 TALLEYVILLE POST Office UST 0.93 2.43 Medium
3592 UNION Park HONDA UST 0.93 2.43 Medium
3591 UNION Park PONTIAC UST 0.93 2.43 Medium
4973 UNION Park PONTIACEMPTY UST 0.93 2.43 Medium
458805 HESS MART 38353 UST 0.92 10000 KERO 2.42 Low
573143 SUNOCO 0013 6804 UST 0.91 1000 USDOL 2.41 Low
517410 JC HAYES UST 0.91 10000 GAS 2.41 Low
PA0047252 Pantos Corp/Painters Crossing PCS/NPDES 1.41 0.07 6.4 2.41 Low
515902 TOLENTINO ENTERPRISES UST 0.91 10000 GAS 2.41 Low
PA0053228 Gramm, Jeffery PCS/NPDES 1.41 0.0005 23.8 2.41 Low
PA0053236 Woodward, Raymond Sr. PCS/NPDES 1.41 0.0005 23.8 2.41 Low
PA0036374 Eaglepoint Dev. Association PCS/NPDES 1.40 0.015 24.5 2.40 Low
PA0053082 Mendenhall Inn PCS/NPDES 1.39 0.0206 5.1 2.39 Low
PA0050458 Little Washington Drainage Co. PCS/NPDES 1.39 0.0531 26.4 2.39 Low
PA0057274 Michael & Antionette Hughs PCS/NPDES 1.39 0.0005 24.5 2.39 Low
505452 HESS 38307 UST 0.89 10000 DIESL 2.39 Low
505452 HESS 38307 UST 0.89 10000 GAS 2.39 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
569389 SUNOCO 0014 1028 UST 0.88 10000 DIESL 2.38 Low
510844 SCOTT FAMILY PARTNERSHIP UST 0.88 4000 GAS 2.38 Low
250910 ALCOA FLEXIBLE PKG DOWNINGTOWN PLT
AST 0.87 3000 OTHER 2.37 Low
569522 GETTY 69730 UST 0.87 15000 GAS 2.37 Low
4741 Academy of Visitation UST 0.85 2.35 Low
4271 Acme Market #1205 UST 0.85 2.35 Low
4468 AstraZeneca Pharmaceuticals LP UST 0.85 2.35 Low
5937 BARONE JIM UST 0.85 2.35 Low
4517 Bayard Property UST 0.85 2.35 Low
6077 BLAIR Property UST 0.85 2.35 Low
4358 Brosius Eliason Company UST 0.85 2.35 Low
6345 Brown Property UST 0.85 2.35 Low
4497 Bush Special School UST 0.85 2.35 Low
4323 Catholic Diocese of Wilmington UST 0.85 2.35 Low
4324 Catholic Diocese of Wilmington UST 0.85 2.35 Low
5063 CHARIS HOUSE GRACE Church UST 0.85 2.35 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
4229 CIGNA Corporation UST 0.85 2.35 Low
4500 Concord High School UST 0.85 2.35 Low
4275 Council of the Devon UST 0.85 2.35 Low
4175 Delaware Motor Sales Body UST 0.85 2.35 Low
4573 DR Charles L MINOR UST 0.85 2.35 Low
4532 duPont Property IRENE UST 0.85 2.35 Low
3874 Exxon/Louis Novakis #27238 UST 0.85 2.35 Low
3982 FISKEKILL Estate UST 0.85 2.35 Low
4042 Former Dupont Elementary School UST 0.85 2.35 Low
6319 Former HADFIELD SEAFOOD UST 0.85 2.35 Low
6137 Former Mobil Station UST 0.85 2.35 Low
6349 Former WELSH Property UST 0.85 2.35 Low
5124 FormerLY BP GAS & GO UST 0.85 2.35 Low
4675 Frederic A Blank UST 0.85 2.35 Low
4872 GEORGE EDMONDS UST 0.85 2.35 Low
3944 Getty Service Station 08676 UST 0.85 2.35 Low
4518 GIOFFRE FRANK J UST 0.85 2.35 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
5085 Harrington Property UST 0.85 2.35 Low
4917 HERLIHY Property UST 0.85 2.35 Low
4379 Highlands Elementary School UST 0.85 2.35 Low
4545 HIGHLANDS IMMANUEL Church UST 0.85 2.35 Low
4677 INVERGARRY UST 0.85 2.35 Low
4540 Laird Property UST 0.85 2.35 Low
4923 LAZYBOY FURNITURE SHOWCAS UST 0.85 2.35 Low
4452 M Fierro & Sons Inc UST 0.85 2.35 Low
5080 May Property UST 0.85 2.35 Low
4980 Merkel UST 0.85 2.35 Low
4492 Michael L Hershey UST 0.85 2.35 Low
4875 Monument Square Apartments UST 0.85 2.35 Low
6287 Padua Academy UST 0.85 2.35 Low
4521 Pennsylvania Avenue Association UST 0.85 2.35 Low
3541 Pep Boys UST 0.85 2.35 Low
6074 POTTER Office Building UST 0.85 2.35 Low
5025 ROWLAND Property WALTER UST 0.85 2.35 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
6153 ROYAL CLEANERS UST 0.85 2.35 Low
6199 RUST Estate UST 0.85 2.35 Low
6078 ST ANTHONYS Church UST 0.85 2.35 Low
4311 ST MARY MAGDALEN Church UST 0.85 2.35 Low
4527 ST STEPHENS LUTHERAN Church UST 0.85 2.35 Low
3976 State LINE MACHINE Inc UST 0.85 2.35 Low
5098 THE PILOT School Inc UST 0.85 2.35 Low
3683 Tower Hill School UST 0.85 2.35 Low
6231 West END NEIGHBORHOOD HOUSE UST 0.85 2.35 Low
4489 WILKINSON Property BENJAMIN UST 0.85 2.35 Low
4631 WOODLAWN TRUSTEES UST 0.85 2.35 Low
458805 HESS MART 38353 UST 0.84 10000 GAS 2.34 Low
517410 JC HAYES UST 0.83 8000 DIESL 2.33 Low
569392 COUNTRYSIDE FOOD MART & DELI UST 0.83 10000 GAS 2.33 Low
569107 ZEKES SVC STA UST 0.82 10000 GAS 2.32 Low
569277 SUNOCO 0012 4180 UST 0.82 8000 GAS 2.32 Low
PA0050547 Indian Run Village PCS/NPDES 1.31 0.0375 28.9 2.31 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
569655 GETTY 69242 UST 0.81 10000 GAS 2.31 Low
569601 BRUNO & SONS UST 0.80 12000 GAS 2.30 Low
510844 SCOTT FAMILY PARTNERSHIP UST 0.80 2000 NMO 2.30 Low
PA0052990 Mitchell, Rodney PCS/NPDES 1.28 0.0005 28.7 2.28 Low
PA0056073 Vreeland, Russell PCS/NPDES 1.28 0.0005 28.7 2.28 Low
569743 GETTY 69724 UST 0.78 10000 GAS 2.28 Low
PA0055492 Topp, John & Jane PCS/NPDES 1.28 0.0005 28.9 2.28 Low
PA0050229 unknown PCS/NPDES 1.28 0.0005 28.9 2.28 Low
4801 Alfred I Dupont Institute UST 0.78 2.28 Low
3545 Diver Chevrolet UST 0.78 2.28 Low
4616 Former HESSLER Building UST 0.78 2.28 Low
4552 KENTMERE/MERCIFUL REST SOCIETY
UST 0.78 2.28 Low
3886 LYNAMS Mobil UST 0.78 2.28 Low
4680 Raskal Foundation UST 0.78 2.28 Low
4578 ROSIN REALTOR UST 0.78 2.28 Low
4758 SHINN PAINT CO FRANK B UST 0.78 2.28 Low
City of Wilmington Source Water Protection Plan
Page 314
NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
3680 Wilmington Friends School UST 0.78 2.28 Low
569389 SUNOCO 0014 1028 UST 0.77 8000 GAS 2.27 Low
569392 COUNTRYSIDE FOOD MART & DELI UST 0.75 8000 GAS 2.25 Low
PA0054691 Stoltzfus Ben Z. PCS/NPDES 1.25 0.0005 30.2 2.25 Low
569170 FADDIS CONCRETE PROD AST 0.73 500 DIESL 2.23 Low
PA0051365 West Chester Area Mun. Authority PCS/NPDES 1.23 0.369 15.7 2.23 Low
569601 BRUNO & SONS UST 0.72 10000 GAS 2.22 Low
569180 SUNOCO 0343 4008 UST 0.72 10000 GAS 2.22 Low
7936 Alexis I DuPont High School HW_Gen 1.45 2.20 Low
7152 State Line Mach Inc HW_Gen 1.45 2.20 Low
7232 Wilmington Piece Dye Co HW_Gen 1.45 2.20 Low
PA0036161 Lincoln Crest MHP STP PCS/NPDES 1.20 0.036 33.5 2.20 Low
PA0057231 Archie & Cloria Shearer PCS/NPDES 1.16 0.0005 33.5 2.16 Low
569107 ZEKES SVC STA UST 0.66 6000 DIESL 2.16 Low
510844 SCOTT FAMILY PARTNERSHIP UST 0.65 2000 USDOL 2.15 Low
569737 EAGLE MOBIL UST 0.64 8000 DIESL 2.14 Low
569737 EAGLE MOBIL UST 0.64 8000 GAS 2.14 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
PA0036412 Tel Hai Retirement Community PCS/NPDES 1.13 0.055 36.8 2.13 Low
PA0056324 Mobil SS#16 - GPB PCS/NPDES 1.12 0.044 17.0 2.12 Low
270147 EXTON TERM AST 0.61 1000 HZSUB 2.11 Low
510844 SCOTT FAMILY PARTNERSHIP UST 0.61 1000 HZSUB 2.11 Low
270147 EXTON TERM AST 0.60 350 HZSUB 2.10 Low
270147 EXTON TERM AST 0.59 300 USDOL 2.09 Low
PA0057339 Brian & Cheryl Davidson PCS/NPDES 1.08 0.0005 36.8 2.08 Low
517410 JC HAYES UST 0.57 6000 GAS 2.07 Low
569737 EAGLE MOBIL UST 0.56 6000 GAS 2.06 Low
517410 JC HAYES UST 0.55 1000 KERO 2.05 Low
463960 VA MED CTR UST 0.53 2000 DIESL 2.03 Low
463960 VA MED CTR UST 0.50 1000 DIESL 2.00 Low
PA0055531 Khalife, Paul PCS/NPDES 1.00 0.0007 20.1 2.00 Low
569737 EAGLE MOBIL UST 0.48 4000 KERO 1.98 Low
569406 EAST FALLOWFIELD TWP CHESTER CNTY
UST 0.47 1000 DIESL 1.97 Low
569406 EAST FALLOWFIELD TWP CHESTER CNTY
UST 0.47 1000 GAS 1.97 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
463960 VA MED CTR UST 0.45 1000 DIESL 1.95 Low
463960 VA MED CTR UST 0.45 1000 DIESL 1.95 Low
PA0027987 Pennsylvania Tpk./Caruiel Service Plaza
PCS/NPDES 0.94 0.05 24.5 1.94 Low
463960 VA MED CTR UST 0.42 2500 GAS 1.92 Low
PA0050005 Sun Company PCS/NPDES 0.87 0.14 10.8 1.87 Low
PA0011568-001
Lukens Steek Co. PCS/NPDES 0.81 0.5 27.5 1.81 Low
PA0011568-016
Lukens Steek Co. PCS/NPDES 0.81 0.5 27.5 1.81 Low
463960 VA MED CTR UST 0.27 1500 DIESL 1.77 Low
PA0055697 Spring Run Estates PCS/NPDES 0.77 0.049 31.2 1.77 Low
PA0051497 Lenape Forge PCS/NPDES 0.76 0.03 10.8 1.76 Low
7579 Alfred I DuPont Institute HW_Gen 0.97 1.72 Low
7897 Amoco #711 HW_Gen 0.97 1.72 Low
7153 Blue Swan Inc HW_Gen 0.97 1.72 Low
7704 Concord Mall Cleaners HW_Gen 0.97 1.72 Low
7498 Custom Auto Body Inc HW_Gen 0.97 1.72 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
7851 Cutler Camera HW_Gen 0.97 1.72 Low
7402 Delaware Mitsubishi HW_Gen 0.97 1.72 Low
7116 Diver, Frank W Inc HW_Gen 0.97 1.72 Low
7508 DuPont Country Club HW_Gen 0.97 1.72 Low
7148 Eden Buick HW_Gen 0.97 1.72 Low
6990 Exxon HW_Gen 0.97 1.72 Low
6949 Fairfax Valet Cleaners HW_Gen 0.97 1.72 Low
7250 Fairfax Valet Cleaners HW_Gen 0.97 1.72 Low
7884 J & M Litterelle Inc. HW_Gen 0.97 1.72 Low
7001 Jiffy Lube HW_Gen 0.97 1.72 Low
7783 Kays Dry Cleaners HW_Gen 0.97 1.72 Low
7010 Larrys Amoco HW_Gen 0.97 1.72 Low
7717 Larrys Amoco HW_Gen 0.97 1.72 Low
7809 Lynams Service Station HW_Gen 0.97 1.72 Low
7961 McClafferty Printing HW_Gen 0.97 1.72 Low
7462 One Hour Martinizing HW_Gen 0.97 1.72 Low
7997 R&R Dipping & Paint Stripping HW_Gen 0.97 1.72 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
7421 Royal Cleaners HW_Gen 0.97 1.72 Low
7209 Seymours Cleaners HW_Gen 0.97 1.72 Low
6974 Shell Oil Co. HW_Gen 0.97 1.72 Low
7636 Shell Oil Company HW_Gen 0.97 1.72 Low
7262 St Francis Hospital Inc HW_Gen 0.97 1.72 Low
7549 Star Enterprise HW_Gen 0.97 1.72 Low
7551 Star Enterprise HW_Gen 0.97 1.72 Low
6920 State Line Mach Inc. HW_Gen 0.97 1.72 Low
7963 Steve Swyka Auto Repair Spec HW_Gen 0.97 1.72 Low
6998 Sunoco HW_Gen 0.97 1.72 Low
7422 Towne & Country Cleaners HW_Gen 0.97 1.72 Low
8000 Union Park Pontiac Inc. HW_Gen 0.97 1.72 Low
PA0056561 Richard M. Armstrong Co. PCS/NPDES 0.64 0 14.4 1.64 Low
PA0051918 Pepperidge Farms PCS/NPDES 0.63 0.144 20.8 1.63 Low
PA0054747 Trans-Materials, Inc. PCS/NPDES 0.62 0 15.1 1.62 Low
PA0053561 Johnson Matthey PCS/NPDES 0.61 0.036 17.0 1.61 Low
PA0054305 Sun Co. Inc. (R&M) PCS/NPDES 0.58 0 17.0 1.58 Low
City of Wilmington Source Water Protection Plan
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NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
PA0030228 Downingtown I&A School PCS/NPDES 0.50 0.0225 20.8 1.50 Low
PA0057126 Hess Oil SS # 38291 PCS/NPDES 0.48 0 20.8 1.48 Low
PA0053678 Lambert Earl R. PCS/NPDES 0.48 0 20.8 1.48 Low
PA0053660 Mobil Oil Company #016 PCS/NPDES 0.48 0 20.8 1.48 Low
6503 CONTAINER CORP SFUND 0.97 1.47 Low
PA0012416 Coatesville Water Plant Rock Run PCS/NPDES 0.42 0.14 28.7 1.42 Low
PA0057045 Shyrock Brothers, Inc. PCS/NPDES 0.40 0 23.9 1.40 Low
PA0052949 Phila. Suburban Water Co. PCS/NPDES 0.39 0 24.5 1.39 Low
PA0053821 Chester County Aviation Inc. PCS/NPDES 0.31 0 27.5 1.31 Low
PA0052728 Farmland Industries Inc./Turkey Hill PCS/NPDES 0.25 0.0004 30.0 1.25 Low
598074 CCSWA LANCHESTER STABILIZED DSPL
Com/Hazwaste 0.75 Low
252600 DELAWARE CONTAINER COMPANY, INC.
Com/Hazwaste 0.75 Low
598074 IU CONVERSIONS SYS DSPL SITE Com/Hazwaste 0.75 Low
6614 BANCROFT MILLS- PRE REMEDIAL SFUND -0.48 0.02 Low
7946 Amoco #711 HW_Gen -0.97 -0.22 Low
6993 Pep Boys HW_Gen -0.97 -0.22 Low
City of Wilmington Source Water Protection Plan
Page 320
NPDES NPDES UST UST
MASTERID Site Name Site Type PS Score Flow (MGD)
Intake Distance (miles)
Capacity (gallons)
Substance Code
Overall score
Rank
6966 Towne & Country HW_Gen -0.97 -0.22 Low
City of Wilmington Source Water Protection Plan
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Appendix B
Grant Funding In the Brandywine Watershed
City of Wilmington Source Water Protection Plan
Page 322
TABLE B-1 – Grant Funding In the Brandywine Watershed From Pennsylvania
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Brandywine Conservancy
Odell Property Acquistion / Brandywine Battlefield
Open Space Acquisition
$4,919,300 $1,000,000 $300,000 25.2 GG2 2006 Chester
Brandywine Valley Association
Kranich Property Acquisition
Critical Habitat Acquisition
$270,000 $55,000 $50,000 4.3 GG1 2004 Chester
Caln Township Lloyd Park Master
Plan Master Site
Development Plan $30,000 $15,000 $15,000
COMM_Key 2003 Chester
Caln Township Lloyd Park Phase 1
Development Park Rehab / Dev
Project $594,700 $200,000 $200,000
COMM_Key 2006 Chester
Caln Township King Highway Master
Plan Master Site
Development Plan $35,000 $17,500 $17,000
COMM_Key 2006 Chester
Charlestown Township
McDevitt Conservation
Easement Land Acquisition $2,895,000 $1,447,500 $200,000 65.6 COMM_Key 2007 Chester
Charlestown Township
Stevens Property Conservation
Easement Land Acquisition $159,400 $79,700 $79,000 7.6 COMM_Key 2007 Chester
Charlestown Township
Coleman Conservation
Easement (Pigeon Run)
Land Acquisition $852,700 $426,400 $109,000 9 COMM_Key 2007 Chester
City of Wilmington Source Water Protection Plan
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Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Chester County Exton Park Site Park Rehab / Dev
Project $510,000 $255,000 $200,000
COMM_Key 2003 Chester
Chester County Black Rock Sanctuary
- Phase III Park Rehab / Dev
Project $392,800 $196,400 $195,000
LWCF 2004 Chester
Chester-Ridley-Crum Watersheds
Association
Crum Creek Watershed
Conservation Plan
Rivers Conservation Plan
$159,100 $79,500 $70,000
RIVER_Key 2003 Chester, Delaware
Coatesville City Palmer Park Park Rehab / Dev
Project $3,000,000 $500,000 $100,000
COMM_Key 2003 Chester
Coatesville City Brandywine Creek
Trail Park Rehab / Dev
Project $1,500,000 $250,000 $250,000
COMM_Key 2007 Chester
Downingtown Borough
Sky's the Limit All-Abilities Playground
Project
Park Rehab / Dev Project
$374,400 $100,000 $75,000
COMM_Key 2004 Chester
East Bradford Township
Paradise Farms Easement Project
Land Acquisition $3,993,000 $1,996,500 $200,000 330.8 GG1 2004 Chester
East Bradford Township
Sykes Property Acquisition
Land Acquisition $399,000 $179,600 $179,000 23 GG2 2006 Chester
East Brandywine Township
Community Park Addition / Brown
Property Land Acquisition $165,000 $50,000 $50,000 7 COMM_Key 2005 Chester
City of Wilmington Source Water Protection Plan
Page 324
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
East Fallowfield Township
Community Park Development - Phase
1
Park Rehab / Dev Project
$550,000 $250,000 $250,000
COMM_Key 2006 Chester
East Vincent Township
Francis Parcel Acquisition
Land Acquisition $138,900 $69,400 $10,900 3.2 COMM_Key 2003 Chester
East Vincent Township
Reiff Tract Acquisition
Land Acquisition $1,827,500 $912,500 $800,000 36 COMM_Key 2007 Chester
Franklin Township Trail Feasibility
Study Feasibility Study $38,000 $19,000 $19,000
COMM_Key 2006 Chester
Franklin Township Howard Property
Acquisition Land Acquisition $482,000 $241,000 $241,000 28.9 GG2 2006 Chester
French & Pickering Creeks Conservation
Trust, Inc.
Landscape Conservation Plan
$50,000 $25,000 $25,000
GG1 2005 Chester
French & Pickering Creeks Conservation
Trust, Inc. Miller Marsh Project
Open Space Acquisition
$105,000 $52,200 $52,000 14.2 LT_Key 2003 Chester
French & Pickering Creeks Conservation
Trust, Inc.
French Creek Trail Easement
Open Space Acquisition
$155,000 $77,500 $75,000 3.8 LT_Key 2005 Chester
Green Valleys Association of
Southeastern PA
Sustainable Municipal Watershed
Management
Rivers Conservation Implementation
Project $292,000 $115,000 $42,500
RIVER_Key 2003 Chester
City of Wilmington Source Water Protection Plan
Page 325
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Kennett Square Borough
Red Clay Greenway Trail
Park Rehab / Dev Project
$540,100 $100,000 $50,000
COMM_Key 2003 Chester
Kennett Township Kennett Pike
Bikeway Study Trail Study $97,400 $42,200 $42,000
COMM_Key 2006 Chester
Kennett Township Land Trust
Whittle Conservation Easement
Open Space Acquisition
$1,770,300 $550,000 $450,000 44 LT_Key 2007 Chester
Lancaster County Conservancy
Octorara Creek Acquisition
Rivers Conservation Acquisition
$782,210 $391,100 $391,000 150 GG2 2007 Chester, Lancaster
London Britain Township
Nichol Park Addition (Dehorty
Acquisition) Land Acquisition $398,000 $199,000 $199,000 14.5 COMM_Key 2005 Chester
London Britain Township
Nichol Park Expansion Project
Master Site Development Plan
$25,000 $12,500 $12,500
COMM_Key 2007 Chester
London Britain Township
Mason-Dixon Greenway South Trail
Park Rehab / Dev Project
$506,300 $250,000 $250,000
COMM_Key 2007 Chester
London Britain Township Land
Trust Walters Easement
Critical Habitat Acquisition
$719,300 $359,700 $300,000 26 LT_Key 2007 Chester
London Grove Township
Community Park Master Site Plan
Master Site Development Plan
$70,000 $35,000 $35,000
COMM_Key 2005 Chester
Natural Lands Trust, Inc.
Birch Run Forest Preserve Project
Rivers Conservation Acquisition
$432,000 $230,000 $200,000 112.4 RIVER_Key 2003 Chester
City of Wilmington Source Water Protection Plan
Page 326
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Natural Lands Trust, Inc.
White Clay Creek Preserve Expansion
Critical Habitat Acquisition
$1,800,000 $900,000 $700,000 133 GG1 2003 Chester
Natural Lands Trust, Inc.
Sadsbury Woods Preserve
Critical Habitat Acquisition
$597,000 $298,500 $295,000 81 GG1 2003 Chester
Natural Lands Trust, Inc.
Paradise Farms Easement
Critical Habitat Acquisition
$3,993,000 $1,996,500 $400,000 340.8 GG1 2004 Chester
Natural Lands Trust, Inc.
Great Marsh Easement
Critical Habitat Acquisition
$836,500 $418,000 $350,000 163.8 GG1 2004 Chester
Natural Lands Trust, Inc.
Karillian Property Acquisition
Open Space Acquisition
$275,000 $137,500 $137,500 4.7 LT_Key 2005 Chester
Natural Lands Trust, Inc.
Armstrong East Property Acquisition
Open Space Acquisition
$840,000 $420,000 $420,000 65.8 LT_Key 2005 Chester
Natural Lands Trust, Inc.
Skiles Property Acquisition
(Sadsbury Woods)
Open Space Acquisition
$75,000 $37,500 $37,500 10 LT_Key 2005 Chester
Natural Lands Trust, Inc.
Indian Run Easement Critical Habitat
Acquisition $1,520,000 $760,000 $760,000 106.8 GG2 2006 Chester
Natural Lands Trust, Inc.
Spackman Farm Easement
Open Space Acquisition
$1,130,000 $565,000 $565,000 52 GG2 2006 Chester
Natural Lands Trust, Inc.
Whittaker Farm Easement
Open Space Acquisition
$733,600 $366,800 $326,000 30 GG2 2006 Chester
City of Wilmington Source Water Protection Plan
Page 327
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Natural Lands Trust, Inc.
Whittaker Property Acq.
Open Space Acquisition
$50,000 $25,000 $25,000 22 GG2 2006 Chester
Natural Lands Trust, Inc.
Unionville Barrens Acquisition
Open Space Acquisition
$5,200,000 $2,600,000 $1,000,000 261 LT_Key 2006 Chester
Natural Lands Trust, Inc.
Preserve Recreation Planning Project
$154,900 $55,000 $50,000
LT_Key 2006 Chester, Delaware,
Montgomery
New Garden Township
Greenways Plan Greenway Plan $35,000 $17,500 $17,500
COMM_Key 2007 Chester
North Coventry Township
Coventry Woods Acq.- Phase II--Brown / Barnard Properties
Land Acquisition $178,000 $239,000 $205,000 47.6 COMM_Key 2003 Chester
North Coventry Township
Coventry Woods, Phase 3
Land Acquisition $249,600 $124,800 $120,000 31.4 COMM_Key 2004 Chester
North Coventry Township
Coventry Woods - Phase IV(Salyor
Property) Land Acquisition $143,000 $71,500 $71,500 16.3 COMM_Key 2005 Chester
North Coventry Township
Nueva Esperanza Property Acquisition
Land Acquisition $852,000 $426,000 $426,000 104.1 COMM_Key 2006 Chester
North Coventry Township
Baker Property Acquisition
Land Acquisition $730,000 $365,000 $350,000 52.7 COMM_Key 2006 Chester
North Coventry Township
Shaner / Kauffman Properties
Land Acquisition $110,000 $55,000 $55,000 8.9 COMM_Key 2007 Chester
City of Wilmington Source Water Protection Plan
Page 328
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Oxford Area Recreation Authority
Gray Farm Master Site Plan
Master Site Development Plan
$40,000 $20,000 $20,000
COMM_Key 2004 Chester
Oxford Area Recreation Authority
Oxford Area Regional Park
Park Rehab / Dev Project
$500,000 $200,000 $200,000
COMM_Key 2007 Chester
Parkesburg Borough Minch Park-Phase 2
Development Park Rehab / Dev
Project $585,500 $292,700 $200,000
COMM_Key 2006 Chester
Pennsbury Land Trust
Mendenhall Conservation
Easement
Open Space Acquisition
$1,298,700 $231,900 $231,900 8.9 GG2 2006 Chester
Pennsylvania Horticultural
Society
Southeastern Pennsylvania Tree
Cover Project
Conservation / Sound Land Use Plan
$1,000,000 $1,540,000 $1,540,000
GG1 2004
Bucks, Chester, Delaware,
Montgomery, Philadelphia
Phoenixville Borough
Melchiorre Tract Park MSDP
Master Site Development Plan
$25,000 $12,500 $12,500
COMM_Key 2004 Chester
Phoenixville Borough
Schuylkill River Trail Park Rehab / Dev
Project $252,200 $126,100 $126,100
COMM_Key 2005 Chester
Phoenixville Borough
Reservoir Park Expansion Acquisition
Land Acquisition $935,000 $467,500 $467,500 7.4 GG2 2006 Chester
Phoenixville Borough
Thornton Park Park Rehab / Dev
Project $326,800 $163,400 $60,000
COMM_Key 2006 Chester
City of Wilmington Source Water Protection Plan
Page 329
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Pocopson Township Community Trail Feasibility Study
Trail Study $433,000 $135,000 $14,000
COMM_Key 2005 Chester
Sadsbury Township Bert Reel Park
Renovation Park Rehab / Dev
Project $121,300 $60,600 $60,000
COMM_Key 2006 Chester
Schuylkill River Greenway
Association Land and Water Trail
Park Rehab / Dev Project
$331,700 $165,800 $120,000
GG1 2005 Berks, Chester, Montgomery, Philadelphia
Schuylkill River Greenway
Association
Schuylkill River Heritage Area
Development Hubs
Park Rehab / Dev Project
$150,000 $75,000 $60,000
GG1 2006 Berks, Chester, Montgomery, Philadelphia
South Coventry Township
Woody's Woods Open Space Acquisition
Land Acquisition $140,000 $70,000 $70,000 17.8 COMM_Key 2005 Chester
Thornbury Township
Squire Cheyney Pk / Waln Run Pk. Master
Site Plans
Master Site Development Plan
$60,000 $30,000 $30,000
COMM_Key 2005 Chester
Tredyffrin Township
Westover Park Master Site Plan
Master Site Development Plan
$43,100 $21,600 $20,000
COMM_Key 2004 Chester
Tredyffrin Township
West Swedesford Road Greenways
Acquisition Land Acquisition $800,000 $200,000 $200,000 5.4 COMM_Key 2004 Chester
Tredyffrin Township
Westover Park Development
Park Rehab / Dev Project
$1,346,200 $250,000 $250,000
COMM_Key 2006 Chester
City of Wilmington Source Water Protection Plan
Page 330
Applicant Title Description
Total Project
Cost
Grant Amount
Requested
Grant
Acres Acq.
Funding Source
Grant Year
Counties
Upper Oxford Township
Stankywicz Estate Acquisition
Land Acquisition $423,000 $104,000 $104,000 13.9 COMM_Key 2005 Chester
West Caln Township Birch Run Forest - West Acquisition
Land Acquisition $1,100,000 $550,000 $550,000 103 GG2 2006 Chester
West Chester Borough
John O. Green Park - Phase 2
Park Rehab / Dev Project
$97,600 $48,800 $48,000
COMM_Key 2005 Chester
West Sadsbury Township
Zion Hill & Zook Roads Acquisition
Land Acquisition $242,300 $121,200 $110,000 31.9 COMM_Key 2003 Chester
Willistown Conservation Trust
Kirkwood Preserve Acquisition
Open Space Acquisition
$5,038,000 $750,000 $500,000 60 LT_Key 2005 Chester
Willistown Township
Okehocking Preserve - Phase 2
Land Acquisition $1,793,400 $771,200 $750,000 10 LWCF 2003 Chester
Willistown Township
Okehocking Preserve - Phase 3 Acquisition
Land Acquisition $1,500,000 $500,000 $500,000 10 COMM_Key 2005 Chester
Willistown Township
Okehocking Nature Center
Feasibility Study $106,300 $52,000 $52,000
COMM_Key 2007 Chester
Willistown Township
Okehocking Preserve Acquisition - Phase IV
Land Acquisition $1,516,300 $500,000 $500,000 12.8 GG2 2007 Chester
City of Wilmington Source Water Protection Plan
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