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ReseaRch gRoup Jess Brown, Directorphone (941) 371-9832jbrown@carollo.com

eDIToRerin Mackey

DesIgn anD pRoDucTIonLaura corringtonKim LightnerMatthew parrott

ReseaRch SOLUTIONS

This publication is printed with soy inks on FSC®- certified 60% post-consumer waste recycled content.

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Phoenix, Arizona Yuma, Arizona Fresno, California Inland Empire, California Los Angeles, California Orange County, California Pasadena, California Sacramento, California San Diego, California San Francisco, California Sunnyvale, California Ventura County, California Walnut Creek, California Denver (Broomfield), Colorado Denver (Littleton), Colorado Broward County, Florida Miami, Florida Orlando, Florida Palm Beach County, Florida Sarasota, Florida Boise, Idaho Chicago, Illinois Kansas City, Missouri Omaha, Nebraska Las Vegas, Nevada Reno, Nevada Oklahoma City, Oklahoma Portland, Oregon Austin, Texas Dallas, Texas Fort Worth, Texas Houston, Texas Salt Lake City, Utah Seattle, Washington

The Water Research Foundation (WaterRF) has published the final report for the project entitled “UV Disinfection Knowledge Base.” This $730,000-project, led by Carollo, provides a comprehensive snapshot of the state-of-the-art of drinking water UV disinfection in the U.S. and Canada. Data on the implementation of UV disinfection, collected through utility and vendor surveys, is included in a MicroSoft Access database provided as part of the report. Analysis of that data describes who is implementing UV disinfection, what technologies are being selected, UV system design

criteria, component performance and cost data, and lessons learned.

Supplementing the survey are detailed on-site evaluations of UV system performance at eight UV installations. Findings from

these on-site evaluations were used to develop a UV system maintenance and troubleshooting guide. Last, the report describes findings from a pilot-scale evaluation of mercury release following lamp breaks, including recommendations for preventing and mitigating such events.

WaterRF Publishes UV Disinfection Knowledge Base Report

WateReuse Research Foundation Publishes Reclaimed Water Report

KeY Team membeRharold Wright (hwright@carollo.com)

KeY Team membeRJeff bandy, Ph.D. (jbandy@carollo.com)

Bridging the Gap

CommentaryA Sweeter Thing Was Never Found: When Life Gives You Rotten Eggs, Make Biomethane

Feature StoryWastewater Planning for the Next 50 Years with a Focus on Solids

Project Updates

What’s New

In this Issue

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Carollo is pleased to announce the publication of the WateReuse Research Foundation Project “Innovative Treatment for Reclaimed Water” (WRF-02-009). The primary goal of WRF 02-009 was to identify a low-cost technology (or technologies) that would simultaneously inactivate pathogens and destroy chemical constituents in secondary filtered wastewater effluent.

Tertiary treatment of wastewater includes a wide variety of treatment targets and applicable technologies. Although several are considered common practice (e.g., chlorination and UV disinfection), many less-established technologies are available to utilities alongside the proven treatment options (e.g., advanced oxidation processes). A study was conducted on current and emerging tertiary and advanced treatment technologies for reclaimed water disinfection and chemical constituent destruction. The objective was to relate capital and operational costs to performance, based on pilot- and bench-scale studies.

Disinfection efficacy was evaluated using indigenous total and fecal coliforms,

indigenous aerobic spore-forming bacteria, and spiked MS2 bacteriophage, reovirus,

coxsackievirus, and adenovirus. The removal and transformation of a suite of spiked chemical constituents, including N-nitrosodimethylamine (NDMA), estrogen-disrupting compounds, and a variety of pharmaceuticals and personal care products, was tracked using a combination of gas chromatography–mass spectrometry and the yeast estrogen screen bioassay, which evaluates the reduction in estrogenic activity (often referred to as “estradiol equivalency”) following treatment.

In addition to pilot- and bench-scale testing, an economic analysis was performed to estimate the costs of treatment by these technologies for a set of water quality objectives, specifically pathogen inactivation to meet California’s Title 22 tertiary recycled water standards (2.2 MPN/100 mL total coliform and a 5-log reduction in viruses) and destruction of 90 percent of estrogenic activity. Ozonation was found to be the most cost-effective technology.

Jess Brown, Ph.D., P.E.CRG Director

Welcome to the Fall 2012 issue of Research Solutions. This issue highlights how Carollo is

working to bridge the gap between good ideas and engineering solutions in wastewater planning, manganese removal, biogas processing, sustainability, UV, and reclaimed water treatment:

To Infinity and Beyond.• Long-range facilities planning requires a balance among regulatory, technical, economic, environmental, social, and political drivers. This article describes a rigorous planning approach that Carollo employed to develop a 50-year biosolids handing plan.Manganese Removal…Naturally.• Converting conventional “greensand-type” filters to biofilters for Mn removal can be tricky due to the reservoir of Mn built up on the filter media. Engineered biofiltration is changing all that.Sweet Biogas…an Oxymoron No •More. Carollo has developed an innovative process for removing hydrogen sulfide and carbon dioxide from gas produced during anaerobic digestion.Envision the Possibilities.• Quantifying “greenness” doesn’t need to be rocket science, but it does need to be rigorous and defensible. The Envision™ rating system meets those criteria…learn how it can be used to provide a robust sustainability assessment framework.

You’ll also learn about new Carollo-led WERF and WaterRF publications on UV, innovative reclaimed water treatment, and trace organic compound (TOrC) removal. We believe that creativity, science, and technology must be integrated with sound engineering practice to meet the complex challenges associated with aging infrastructure, increasingly stringent water quality and discharge requirements, the movement toward sustainability, and the growing water supply shortages facing our industry. I hope you find something useful in these articles. Do not hesitate to contact the primary authors or me directly for further discussion.

Happy Holidays!

cOmmeNTaRY

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Bridging the Gap

One of the biggest challenges to the beneficial reuse of natural biogas has always been the contaminants it carries along with it. Newer air quality regulations and more efficient combustion processes have required that the gas produced from anaerobic digestion be cleaned before it is used in cogeneration equipment. In certain areas of the country, even the hydrogen sulfide must be removed before the digester gas can be flared.

In the petrochemical industry, the natural gas produced from oil wells is “sweetened” through a reaction with an amine (known as the Girdler process) to remove hydrogen sulfide from the gas stream. In our neck of the woods, the gas is usually reacted with

iron in iron sponge scrubbers. There are several commercially available variations on the iron sponge process, but all of them rely on adsorption and reaction of the sulfide into an iron matrix, regeneration of the matrix by oxidation of the iron to ferric oxide and oxidation of sulfide to elemental sulfur or sulfates, and discharge back to the head of the plant.

A New Approach to Sweetening Wastewater Treatment BiogasIn setting out to change the status quo, we identified the key assets at a wastewater treatment plant that differ from other industries that deal with hydrogen sulfide in gas. The biggest difference is WATER. We have a steady supply of water, typically under high pressure from the washwater or plant water systems.

Once these differences were identified, we were able to define a process that uses our biggest asset to sweeten one of our biggest challenges and pilot test our design. Table 1

A Sweeter Thing Was Never Found: When Life Gives You Rotten Eggs, Make Biomethane

By Rudy Kilian, P.E., PMP (rkilian@carollo.com), Toshio Shimada, Ph.D., P.E.

Iron sponge filters are commonly used in wastewater treatment plants to remove hydrogen sulfide from biogas.

shows the “industry standard” values for biogas as well as the range and composition of the biogas tested at the four sites at which our pilot plant was installed.

Table 1 also shows the difference in observed gas quality between published textbook values and the actual gas composition we measured. In effect, for facilities that do not add iron as part of their collection or treatment processes, the amount of sulfides in their gas may be significantly greater than the “textbook” values.

What allows our invention to work is the differential solubility of the hydrogen sulfide and carbon dioxide to methane. Table 2 shows the solubility differences for these three gases in water.

When we introduce these gases under pressure to water, the carbon dioxide and

the hydrogen sulfide preferentially dissolve into the water leaving behind the methane. The photo below shows the embodiment of our invention. The concept is simple: Using the water, of which we have an abundant supply, we generate a vacuum using a Venturi to draw the gas into the system. The gas/water mixture is separated in a gas separator, and the cleaned gas is collected at the top in the degas valve. The water now containing the hydrogen sulfide and the carbon dioxide is drained to the aeration basins where the carbon dioxide is released and the sulfide is converted into sulfate and leaves the plant in solution with the effluent.

The system is extremely efficient at removing not only the hydrogen sulfide but carbon dioxide as well. Table 3 shows the results obtained from pilot testing

the invention at four wastewater treatment facilities.

Additional benefits that this system may have that were not tested include removal of siloxanes, which can also be an air emission problem. Some siloxanes are water soluble and may be removed during this process.

Since methane is soluble in water, a mass balance was developed to identify the amount of methane that would be “lost” to the water in this process. Based on the solubility of methane presented in Table 1, less than 1.8 percent of the methane treated by the system would be lost to the water, making the system 98.2 percent efficient in methane recovery.

While a lot of additional work is still required to optimize the system and demonstrate its full benefits, the preliminary applications of this technology suggests it has a promising future in wastewater treatment resource recovery.

Special thanks to Mazzei® Injector Company for loaning Carollo the equipment necessary and to the four treatment facilities that hosted the demonstration of this equipment.

CompoundSolubility

ft3 gas/1,000 Gal of Water

Difference

Methane 4.11 N/A

Carbon Dioxide 300.27 730%

Hydrogen Sulfide 256.01 640%

Table 2. Solubility Differences for Three Gases in Water

Component Typical Observed

Methane (by deduction) 55-65% 301, 50-65%

Carbon Dioxide 35-45% 681, 32-39%

Hydrogen Sulfide 1,500 ppm 7,0001, 150-8,000

Water Saturated at 95°F Saturated at 95°F

Pressure 2-12 in W.C. 3-7 in W.C.Note:1. Acid Phase Gas Sample

Table 1. “Industry Standard” Values for Biogas and the Range and Composition of the Biogas Tested at the Four Sites

Component Inlet Outlet

Methane (by deduction)

301, 50-65% 95-98%

Carbon Dioxide 681, 32-39% <2%

Hydrogen Sulfide 7,0001, 150-8,000 <3 ppm

Water Saturated at 95° Saturated at 65°2

Pressure 3-7 in W.C. 1.5 psigNotes:1. Acid Phase Gas Sample.2. Water cools gas removing moisture

Table 3. Results Obtained from Pilot Testing the Invention at Four WWTFs

Carollo’s invention was successfully pilot tested at four different wastewater treatment facilities.

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The City of Palo Alto, CA, has operated the Regional Water Quality Control Plant (RWQCP) to treat wastewater for the City and surrounding communities for 78 years without a master plan in place to guide decisions. Recognizing the need for a strategy to deal with future regulations and aging infrastructure, the City hired Carollo to develop a Long Range Facilities Plan (LRFP).

One of the key issues facing the RWQCP was what to do with its solids. The existing multiple hearth incineration process is expensive to operate and maintain, and the incinerators are over 40 years old and showing visible signs of deterioration. In addition, Palo Alto is a community that prides itself on being green, with aggressive goals to be a zero waste community and to reduce energy use and greenhouse gas (GHG) emissions in the near future. There is also a perception by some that incineration is the wrong approach for the community’s solids and that there are newer and better technologies. As such, in developing the LRFP, we had to identify the regulatory issues that would affect solids treatment and disposal over the next 50 years, consider viable new technologies, and use a decision process for evaluating alternatives that matched the community’s values.

Establishing a Decision ProcessTo begin the 2-year planning effort, Carollo met with City staff and stakeholders to define the goals and decision process to be used. In addition to the community’s focus on sustainability, neighbor impacts (noise, truck traffic, odors, and visual impacts) are a concern as the RWQCP has a very compact site that is already filled with treatment processes and is in close proximity to nearby parkland, business parks, and a municipal airport. In other communities, we have used the Triple Bottom Line (TBL) framework to organize goals and criteria into three categories: economic/cost, social/community, and environment. Based on the input received from stakeholders and our experience with applying sustainability concepts, we added a technical category to reflect the criteria that engineers and operators need to consider when making decisions on wastewater treatment. The TBL framework developed for the LRFP used as a basis to compare alternatives is shown in Figure 1.

Considering Regulations while Selecting AlternativesIn developing a 50-year plan, it was necessary to consider not just existing regulations but also the likelihood of future regulations. Shortly after the LRFP project started, the EPA released its draft Sewage Sludge Incineration Rule, which would have established air regulations so strict

that the existing multiple hearth furnaces would not have been able to comply. The final rule, adopted in 2011, has less onerous requirements. However, it is clear that the EPA will continue to look at incineration as a major air pollutant source (especially for mercury) and additional requirements will likely be added at some point(s) during the mandated 5-year regulatory updates.

Other regulatory and political changes that will affect biosolids disposal and beneficial use are also expected in the near- and long-term. The State of California recently adopted a goal of diverting 75 percent of organic wastes from landfills. This means increased pressure to eliminate any organic matter from landfills. Land application of biosolids has also become increasingly

restricted with bans implemented in many counties (Figure 2).

In conclusion, biosolids disposal and/or beneficial use is expected to become more difficult in the future due to landfill disposal pressure and land application limitations. In addition, unless public perception is changed, the future appears to hold limited options for incineration in California, especially with the existing technology. Long-term, reliable options for biosolids include developing marketable products and collaborating on regional solutions.

Evaluating the impact of regulations on biosolids end use/disposal helped focus the alternatives considered for future biosolids treatment. The viable alternatives that were developed in more detail included: 1) converting to a new incineration process with better air pollution controls, (fluidized bed incineration or FBI), 2) newer thermal processing alternatives such as gasification, 3) digestion and dewatering with hauling to

an off-site composting facility, or 4) hauling dewatered untreated solids to one of two regional facilities (one being digestion and the other being gasification).

Comparison of AlternativesIn developing the solids alternatives during the LRFP, the project team presented options to stakeholders on several occasions, including the general advantages (or benefits) and disadvantages of each alternative. Through a qualitative initial screening process that included a subset of the TBL criteria (shown in Figure 1),

By Lydia Holmes, P.E. (lholmes@carollo.com), Sarah Deslauriers

Wastewater Planning for the Next 50 Years with a Focus on Solids

How the City of Palo Alto is applying sustainability ideas to develop a plan

a wide array of choices was narrowed down to a viable set of alternatives. These viable alternatives were then evaluated in greater detail with estimates of costs and GHG emissions.

The GHG emissions estimated for this evaluation included both direct emissions (fuel combustion at the RWQCP, as well as sewage sludge incineration) and indirect emissions (electricity use at the plant, energy use to produce polymer and natural gas consumed on-site, and fuel combustion for biosolids and chemical hauling) generated by RWQCP operations. Both biogenic and non-biogenic sources were identified for each alternative, as shown in Figure 3. However, currently only non-biogenic sources are required for mandatory reporting and are the focus for future reductions.

ConclusionThe City of Palo Alto is still considering its solids options and has yet to decide on a course of action for the future. However, based on the findings of the LRFP, they have decided to retire the existing incinerators by 2019 and proceed with either gasification, anaerobic digestion, or a regional solution. Some of the outstanding questions include proving that gasification is a viable process (its use for biosolids is relatively new) and determining if there are advantages to mixing in other waste streams (green and food waste) for a more comprehensive and more sustainable solution.

FeaTuResTORY

ARIZONA

NEVADA

MEXICO

OREGON

Ban on All Land ApplicationPractical BanBan on Class BClass B Land Application AllowedDeveloping OrdinancesNo Regulations/Ordinances Enacted

DEL

MENDOCINO

SAN FRANCISCO

SISKIYOUMODOC

LASSENSHASTA

DEL

NO

RTE

TEHAMAPLUMAS

GLENN BUTTE SIERRA

NEVADAPLACERYUBA

EL DORADOALPINE

SUTTER

AMADOR

COLUSA

LAKE

SONOMANAPA

YOLO

SOLANO

MARIN CONTRACOSTA

ALAMEDASAN

MATEO SANTACLARA

SANJOAQUIN

TUOLUMNE

MEN

DOCI

NO

HUM

BOLT TRINITY

SANBENITO

TULAREMONTEREY

MERCED

MONO

FRESNO

MADERA

CALAVERAS

STANISLAUS

SACRAMENTO

MARIPOSA

INYO

SAN LUISOBISPO

KERN

KINGS

SAN BERNARDINOSANTA

BARBARA

LOSANGELES

VENTURA

RIVERSIDE

IMPERIALSANDIEGO

ORANGE

Status of County Ordinances

SANTA CRUZ

■ Water Quality to Bay■ Air Quality■ Purchased Electricity■ GHG Emissions■ Chemical Use■ Immobilize Toxins■ Waste Diversion

■ Noise■ Odor■ Visual■ Truck Traffic■ Air Quality■ Landscaping

■ Capital Costs■ O&M Costs■ Life-Cycle Costs■ Rates

■ Process Performance■ Useful Life■ Efficient Site Layout■ Constructability■ Recycled Water Quality

Costs Community EnvironmentalTechnical

Figure 1. The modified Triple Bottom Line framework was used to identify viable solids alternatives for the LRFP.

Figure 2. Solids end use/disposal ordinances throughout California.

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15,000

25,000

20,000

FBI Gasification RegionalGasification

AnaerobicDigestion

RegionalAnaerobicDigestion

30,000BiogenicNon-Biogenic

Figure 3. GHG emissions analysis of viable alternatives for Palo Alto’s RWQCP.

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The Trinity River Authority (TRA) plans to convert the conventional filtration process at the Tarrant County Water Supply Project (TCWSP) Water Treatment Plant (WTP) to biofiltration. The TCWSP currently operates the WTP with a chlorine residual in the filter influent. In order to promote the growth of beneficial organisms, the chlorine feed point will be relocated to downstream of the filters. However, moving this feed point will alter the existing mechanism for manganese (Mn) control used at the WTP. The presence of a chlorine residual promotes the oxidation of soluble Mn. The oxidized Mn species form precipitants (particles) that are removed via mechanical filtration. Although most of the Mn precipitant is removed during filter backwashing, a portion remains attached to the media as manganese oxides (MnOx). The MnOx layers provide an adsorptive surface for the remaining soluble Mn present in the filter feed.

Changing the filtration process to biofiltration is expected to provide long-term water quality improvements with regard to taste and odor removal, biological Mn removal, disinfection, and effluent biostability. However, short-term water quality deterioration may result; the elimination of the upstream chlorine residual will decrease filter feed oxidative reductive potential, which may result in a temporary or intermittent release of media-bound Mn. Wholesale filter media change out prior to the conversion to biofiltration is a common strategy to prevent Mn release. However, the capital cost for new media can exceed several million dollars.

TRA is participating in a Tailored Collaboration with the Water Research Foundation (TC #4448) to investigate optimizing the conversion of a conventional filter to a biological filtration process. The study includes 9 months of bench- and pilot-scale evaluations with a special emphasis on biofilter start-up/acclimation and steady-state operational strategies that

Optimizing Filter Conditions for Manganese Treatment and Media Stabilization during Conversion to Biofiltration

enhance biological Mn treatment and prevent or mitigate Mn release from the filter media. The strategies being tested include optimization of the following conditions: pH, nutrients (orthophosphate and ammonia), substrates, and redox conditions.

Results to date suggest that pH, substrate addition, and nutrient enhancement accelerate biological acclimation for Mn removal (to <1 month), while sustainably preventing filter Mn breakthrough over 20 µg/L, even during high loading events (>200 µg/L). These enhanced operational strategies have also improved filter hydraulics (>35 percent decrease in terminal headloss during a 24 hour filter run).

This research is tailored to address issues that may arise during the conversion from conventional filtration to biofiltration at the TCWSP, but it is applicable to the drinking water industry as a whole. Specifically, this research will augment the existing body of knowledge pertaining to biological drinking water treatment, a relatively new concept in the U.S., but one that is gaining momentum among water utilities.

KeY Team membeRschance Lauderdale, Ph.D., P.e. (clauderdale@carollo.com) Greg Pope, Ph.D., P.e. Kara scheitlin John Zwerneman Gary smith [TRa]

Figure 1. 5-month Mean Total Manganese concentrations for filter influent, and effluents, including tested biofilters and full-scale (chlorinated) conventional filters.

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TRA is participating in a Water Research Foundation Tailored Collaboration (TC #4448) to investigate the optimization of conventional filter conversion to a biological filtration process. The study includes 9 months of bench- and pilot-scale evaluations.

WhaT’sNeW

Does conventional wastewater treatment pose a barrier to emerging contaminants in the environment? Where does the removal take place in the treatment process and what operational strategies can reduce trace organic compounds (TOrCs) in the discharge? How does the cost and effectiveness of conventional treatment compare with advanced technologies for TOrC removal?

These were the key questions that a research team led by Carollo answered in a 2-year-long study funded by the Water Environment Research Foundation (WERF). The final report has now been published, summarizing research findings and recommendations for practitioners. TOrCs comprise various groups of compounds including pharmaceuticals, personal care products, food additives, and other high-production chemicals. Due to the number and variety of compounds present in municipal wastewater influents and effluents, guidance is needed for assessing the removal efficiencies for a wide range of TOrCs in conventional treatment. This study identified a small number of TOrC performance indicators that allow for a rapid characterization of the performance efficiency of conventional wastewater treatment facilities. These were used to assess process efficacy and relative cost-effectiveness.

to assess and protect community, environmental,

and economic benefits on all types and sizes of infrastructure projects.

The Envision™ rating system follows the model established by the U.S. Green Building Council’s LEED™ rating system, with three levels of project recognition or award: Silver, Gold and Platinum; however, in Envision™, the major categories are more targeted to infrastructure-type work. Each major category consists of a varying number of credits.

These are as follows:

Quality of Life.•Leadership.•Resource Allocation.•Natural World.•Climate and Risk.•

But unlike LEED, there are five levels of achievement possible for each credit to give the project team an idea of where they are now and where they could go in the future.

The Envision™ rating system was just released in 2012 and has only been piloted on a few test cases. However, the system shows real promise for offering a robust and applicable sustainability assessment framework for Carollo clients and projects.

KeY Team membeRcourtney eaton, P.e. (ceaton@carollo.com)

KeY Team membeRsTanja Rauch-Williams, Ph.D., P.e. (trauch-williams@carollo.com) andrew salveson, P.e.

A number of tools exist to ‘measure’ certain ‘greenness’ aspects of a project, such as GHG calculations (as highlighted in the Palo Alto RWQCP LRFP project) or Life- Cycle Analysis (LCA). In addition, green building tools, such as Leadership in Energy and Environmental Design (LEED) or the Living Building Challenge, offer guidance and rewards for incorporating sustainable or green building practices into projects. In past work, Carollo has used LEED as a framework for assessing and recommending green building practices for incorporation into wastewater projects, but because LEED is focused specifically on buildings, rather than infrastructure-type work, there is limited carryover and thus, applicability of LEED to many Carollo projects. We were left wondering “Is there a better option?”

The Envision™ rating system may just provide that “better alternative.” Developed through a joint collaboration between the Zofnass Program for Sustainable Infrastructure at the Harvard University Graduate School of Design and the Institute for Sustainable Infrastructure (ISI)1, Envision™ provides a holistic framework for evaluating, rating, and recognizing projects and teams that use transformational, collaborative approaches

Rating System Helps “Envision” Other Possibilities

Envision™ helps teams:Meet sustainability goals.•Be publicly recognized for high levels •of achievement in sustainability.Help communities and project teams •collaborate and discuss, “Are we doing the right project?” and, “Are we doing the project right?”Make decisions about the investment •of scarce resources.Include community priorities in civil •infrastructure projects.

1. The Institute for Sustainable Infrastructure (ISI) is a non-profit organization founded by the American Council of Engineering Companies (ACEC), the American Public Works Association (APWA), and the American Society of Civil Engineers (ASCE).

WERF Publishes TOrC Indicator Removal Report

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The Trinity River Authority (TRA) plans to convert the conventional filtration process at the Tarrant County Water Supply Project (TCWSP) Water Treatment Plant (WTP) to biofiltration. The TCWSP currently operates the WTP with a chlorine residual in the filter influent. In order to promote the growth of beneficial organisms, the chlorine feed point will be relocated to downstream of the filters. However, moving this feed point will alter the existing mechanism for manganese (Mn) control used at the WTP. The presence of a chlorine residual promotes the oxidation of soluble Mn. The oxidized Mn species form precipitants (particles) that are removed via mechanical filtration. Although most of the Mn precipitant is removed during filter backwashing, a portion remains attached to the media as manganese oxides (MnOx). The MnOx layers provide an adsorptive surface for the remaining soluble Mn present in the filter feed.

Changing the filtration process to biofiltration is expected to provide long-term water quality improvements with regard to taste and odor removal, biological Mn removal, disinfection, and effluent biostability. However, short-term water quality deterioration may result; the elimination of the upstream chlorine residual will decrease filter feed oxidative reductive potential, which may result in a temporary or intermittent release of media-bound Mn. Wholesale filter media change out prior to the conversion to biofiltration is a common strategy to prevent Mn release. However, the capital cost for new media can exceed several million dollars.

TRA is participating in a Tailored Collaboration with the Water Research Foundation (TC #4448) to investigate optimizing the conversion of a conventional filter to a biological filtration process. The study includes 9 months of bench- and pilot-scale evaluations with a special emphasis on biofilter start-up/acclimation and steady-state operational strategies that

Optimizing Filter Conditions for Manganese Treatment and Media Stabilization during Conversion to Biofiltration

enhance biological Mn treatment and prevent or mitigate Mn release from the filter media. The strategies being tested include optimization of the following conditions: pH, nutrients (orthophosphate and ammonia), substrates, and redox conditions.

Results to date suggest that pH, substrate addition, and nutrient enhancement accelerate biological acclimation for Mn removal (to <1 month), while sustainably preventing filter Mn breakthrough over 20 µg/L, even during high loading events (>200 µg/L). These enhanced operational strategies have also improved filter hydraulics (>35 percent decrease in terminal headloss during a 24 hour filter run).

This research is tailored to address issues that may arise during the conversion from conventional filtration to biofiltration at the TCWSP, but it is applicable to the drinking water industry as a whole. Specifically, this research will augment the existing body of knowledge pertaining to biological drinking water treatment, a relatively new concept in the U.S., but one that is gaining momentum among water utilities.

KeY Team membeRschance Lauderdale, Ph.D., P.e. (clauderdale@carollo.com) Greg Pope, Ph.D., P.e. Kara scheitlin John Zwerneman Gary smith [TRa]

Figure 1. 5-month Mean Total Manganese concentrations for filter influent, and effluents, including tested biofilters and full-scale (chlorinated) conventional filters.

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Biofilter InfluentF110 Effluent - Unenhanced Biofilter Control ColumnF120 Effluent - Nutrient EnhancedF130 Effluent - Nutrient/pH EnhancedF140 Effluent - Nutrient/Substrate/pH EnhancedFull-Scale Combined Filter Effluent

TRA is participating in a Water Research Foundation Tailored Collaboration (TC #4448) to investigate the optimization of conventional filter conversion to a biological filtration process. The study includes 9 months of bench- and pilot-scale evaluations.

WhaT’sNeW

Does conventional wastewater treatment pose a barrier to emerging contaminants in the environment? Where does the removal take place in the treatment process and what operational strategies can reduce trace organic compounds (TOrCs) in the discharge? How does the cost and effectiveness of conventional treatment compare with advanced technologies for TOrC removal?

These were the key questions that a research team led by Carollo answered in a 2-year-long study funded by the Water Environment Research Foundation (WERF). The final report has now been published, summarizing research findings and recommendations for practitioners. TOrCs comprise various groups of compounds including pharmaceuticals, personal care products, food additives, and other high-production chemicals. Due to the number and variety of compounds present in municipal wastewater influents and effluents, guidance is needed for assessing the removal efficiencies for a wide range of TOrCs in conventional treatment. This study identified a small number of TOrC performance indicators that allow for a rapid characterization of the performance efficiency of conventional wastewater treatment facilities. These were used to assess process efficacy and relative cost-effectiveness.

to assess and protect community, environmental,

and economic benefits on all types and sizes of infrastructure projects.

The Envision™ rating system follows the model established by the U.S. Green Building Council’s LEED™ rating system, with three levels of project recognition or award: Silver, Gold and Platinum; however, in Envision™, the major categories are more targeted to infrastructure-type work. Each major category consists of a varying number of credits.

These are as follows:

Quality of Life.•Leadership.•Resource Allocation.•Natural World.•Climate and Risk.•

But unlike LEED, there are five levels of achievement possible for each credit to give the project team an idea of where they are now and where they could go in the future.

The Envision™ rating system was just released in 2012 and has only been piloted on a few test cases. However, the system shows real promise for offering a robust and applicable sustainability assessment framework for Carollo clients and projects.

KeY Team membeRcourtney eaton, P.e. (ceaton@carollo.com)

KeY Team membeRsTanja Rauch-Williams, Ph.D., P.e. (trauch-williams@carollo.com) andrew salveson, P.e.

A number of tools exist to ‘measure’ certain ‘greenness’ aspects of a project, such as GHG calculations (as highlighted in the Palo Alto RWQCP LRFP project) or Life- Cycle Analysis (LCA). In addition, green building tools, such as Leadership in Energy and Environmental Design (LEED) or the Living Building Challenge, offer guidance and rewards for incorporating sustainable or green building practices into projects. In past work, Carollo has used LEED as a framework for assessing and recommending green building practices for incorporation into wastewater projects, but because LEED is focused specifically on buildings, rather than infrastructure-type work, there is limited carryover and thus, applicability of LEED to many Carollo projects. We were left wondering “Is there a better option?”

The Envision™ rating system may just provide that “better alternative.” Developed through a joint collaboration between the Zofnass Program for Sustainable Infrastructure at the Harvard University Graduate School of Design and the Institute for Sustainable Infrastructure (ISI)1, Envision™ provides a holistic framework for evaluating, rating, and recognizing projects and teams that use transformational, collaborative approaches

Rating System Helps “Envision” Other Possibilities

Envision™ helps teams:Meet sustainability goals.•Be publicly recognized for high levels •of achievement in sustainability.Help communities and project teams •collaborate and discuss, “Are we doing the right project?” and, “Are we doing the project right?”Make decisions about the investment •of scarce resources.Include community priorities in civil •infrastructure projects.

1. The Institute for Sustainable Infrastructure (ISI) is a non-profit organization founded by the American Council of Engineering Companies (ACEC), the American Public Works Association (APWA), and the American Society of Civil Engineers (ASCE).

WERF Publishes TOrC Indicator Removal Report

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ReseaRch gRoup Jess Brown, Directorphone (941) 371-9832jbrown@carollo.com

eDIToRerin Mackey

DesIgn anD pRoDucTIonLaura corringtonKim LightnerMatthew parrott

ReseaRch SOLUTIONS

This publication is printed with soy inks on FSC®- certified 60% post-consumer waste recycled content.

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Phoenix, Arizona Yuma, Arizona Fresno, California Inland Empire, California Los Angeles, California Orange County, California Pasadena, California Sacramento, California San Diego, California San Francisco, California Sunnyvale, California Ventura County, California Walnut Creek, California Denver (Broomfield), Colorado Denver (Littleton), Colorado Broward County, Florida Miami, Florida Orlando, Florida Palm Beach County, Florida Sarasota, Florida Boise, Idaho Chicago, Illinois Kansas City, Missouri Omaha, Nebraska Las Vegas, Nevada Reno, Nevada Oklahoma City, Oklahoma Portland, Oregon Austin, Texas Dallas, Texas Fort Worth, Texas Houston, Texas Salt Lake City, Utah Seattle, Washington

The Water Research Foundation (WaterRF) has published the final report for the project entitled “UV Disinfection Knowledge Base.” This $730,000-project, led by Carollo, provides a comprehensive snapshot of the state-of-the-art of drinking water UV disinfection in the U.S. and Canada. Data on the implementation of UV disinfection, collected through utility and vendor surveys, is included in a MicroSoft Access database provided as part of the report. Analysis of that data describes who is implementing UV disinfection, what technologies are being selected, UV system design

criteria, component performance and cost data, and lessons learned.

Supplementing the survey are detailed on-site evaluations of UV system performance at eight UV installations. Findings from

these on-site evaluations were used to develop a UV system maintenance and troubleshooting guide. Last, the report describes findings from a pilot-scale evaluation of mercury release following lamp breaks, including recommendations for preventing and mitigating such events.

WaterRF Publishes UV Disinfection Knowledge Base Report

WateReuse Research Foundation Publishes Reclaimed Water Report

KeY Team membeRharold Wright (hwright@carollo.com)

KeY Team membeRJeff bandy, Ph.D. (jbandy@carollo.com)

Bridging the Gap

CommentaryA Sweeter Thing Was Never Found: When Life Gives You Rotten Eggs, Make Biomethane

Feature StoryWastewater Planning for the Next 50 Years with a Focus on Solids

Project Updates

What’s New

In this Issue

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Carollo is pleased to announce the publication of the WateReuse Research Foundation Project “Innovative Treatment for Reclaimed Water” (WRF-02-009). The primary goal of WRF 02-009 was to identify a low-cost technology (or technologies) that would simultaneously inactivate pathogens and destroy chemical constituents in secondary filtered wastewater effluent.

Tertiary treatment of wastewater includes a wide variety of treatment targets and applicable technologies. Although several are considered common practice (e.g., chlorination and UV disinfection), many less-established technologies are available to utilities alongside the proven treatment options (e.g., advanced oxidation processes). A study was conducted on current and emerging tertiary and advanced treatment technologies for reclaimed water disinfection and chemical constituent destruction. The objective was to relate capital and operational costs to performance, based on pilot- and bench-scale studies.

Disinfection efficacy was evaluated using indigenous total and fecal coliforms,

indigenous aerobic spore-forming bacteria, and spiked MS2 bacteriophage, reovirus,

coxsackievirus, and adenovirus. The removal and transformation of a suite of spiked chemical constituents, including N-nitrosodimethylamine (NDMA), estrogen-disrupting compounds, and a variety of pharmaceuticals and personal care products, was tracked using a combination of gas chromatography–mass spectrometry and the yeast estrogen screen bioassay, which evaluates the reduction in estrogenic activity (often referred to as “estradiol equivalency”) following treatment.

In addition to pilot- and bench-scale testing, an economic analysis was performed to estimate the costs of treatment by these technologies for a set of water quality objectives, specifically pathogen inactivation to meet California’s Title 22 tertiary recycled water standards (2.2 MPN/100 mL total coliform and a 5-log reduction in viruses) and destruction of 90 percent of estrogenic activity. Ozonation was found to be the most cost-effective technology.