DECENTRALIZED WATER/WASTEWATER REUSE AS NON-POTABLE WATERS FOR RURAL AND URBAN COMMUNITIES

Sushama Pradhan1, Michael T. Hoover2 and Ishwar Devkota3 Abstract Treating and reusing wastewater for non-potable water supply can be an excellent strategy to overcome the life threatening water scarcity situation many communities need to deal with today and that more communities will be facing tomorrow. Locally utilized decentralized wastewater reuse (DWR) systems can help to alleviate existing water supply problems by diverting, treating and reusing wastewater for non-potable water needs. For cities on the North Carolina Outer Banks like Kitty Hawk, Kill Devil Hills and Nags Head where 85% of the housing units depend upon on-site wastewater treatment systems, and with 299 systems /sq. mi, DWR systems can be a pivotal water solution to the overall water supply needs. The DWR waters as non-potable water supplies were studied at multiple scales ranging from the commercial facility at the site-scale up to the satellite treatment plant at the community-scale. Design flow of these facilities ranged from 36,000 gpd to 600,000 gpd.Three DWR systems and two facility-scale decentralized wastewater systems were studied in this project. Water quality data from reuse systems indicated very high quality non-potable water with low levels of indicators for oxygen depletion, contaminants and nutrients. These treated waters were used for golf course irrigation and irrigation of yards and common areas and vehicle washing. Integration of decentralized wastewater reuse as a non-potable water supply within a green building concept can provide sustainable, dependable and affordable water for individual facilities as well as communities.

Key words: Climate change, decentralized wastewater, onsite wastewater, wastewater reuse, water reclamation, non-potable use.

___________________________________

1Sushama Pradhan, Ph. D, NC LSS. Environmental Sr. Specialist, N.C. Department of Health and Human Services, On-Site Water Protection Branch - Division of Public Health, Six Forks Road, Raleigh, NC 27699-1642, USA, Email: sushama.pradhan@dhhs.nc.gov Phone: (919) 707-5063

2 Michael T. Hoover, Ph. D. Retired Professor, formerly with Department of Soil Science, North Carolina State University, Raleigh, NC 27695, USA. Email: mike.hoover.onsiteww@gmail.com Cell: (919) 604-3100 3Ishwar Devkota, PE, N.C. Department of Health and Human Services, On-Site Water Protection Branch - Division of Public Health, Six Forks Road, Raleigh, NC 27699-1642, USA, Email: ishwar.devkota@dhhs.nc.gov

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Introduction

Water, an essential element to all life, is a globally scarce natural resource. Approximately one in nine (750 million people) around the world do not have access to safe water (WHO and UNICEF JMP, 2014). Water crises will become increasingly worse tomorrow, compared to today, as the result of population growth, exponential growing urbanization, changes in human life styles, industrial development and climate change induced drought. Water use in U.S. has increased by 8,000 mgd from 1995 to 2005 (Kenny et al., 2009). Treating and reusing water for non-potable uses and conservation of high valued drinking water can be an excellent strategy to overcome this life threatening water scarcity situation, where demand extensively exceeds supplies. For instances, the places like Tulare County in California, where 1252 houses are without running water. Reuse of reclaimed water/wastewater has considerable potential for use as non-potable waters in rural and urban communities such as for landscape irrigation, toilet flushing, vehicle washing, artificial water features (House et.al, 1999; Ogoshi et.al, 2001) and golf course irrigation (Bahri et.al, 2001).

Unofficially reuse of reclaimed wastewater has been in practice long before guideline for water reuse was first debuted by U.S Environmental Protection Agency in 1980. Since then the number of states adopting water reuse regulations or developing guidelines or design criteria kept increasing. By 2004, 26 states had adopted regulations, and 15 states had guidance governing water reuse (EPA, 2004) which went up to 30 states and one U.S. territory with adopted regulations and 15 states with guidance by 2012 (EPA, 2012). The increasing number of states adopting guidelines indicates the necessity of state’s using reclaimed water. According to the Wate Reuse Association, the national reclaimed water use rate has increased by 15% each year resulting in approximately 2.6 x103 million gallons of reclaimed water currently being reused per day by the early 2000’s (Asano et. al., 2007).

A substantial number of research studies carried on throughout the U.S. have shown that water recycling on the large centralized system scale has proven to be effective and successful in lowering water scarcity creating a new and reliable water supplies (Grinnell and Janga, 2004; FDEP, 2011; NRC, 2012 and O’Neill, and Dobrowolski, 2011and NRC, 2012). According to Bryk et al. (2011), highest percentage of reclaimed water in U.S. goes to agriculture irrigation (29%) followed by landscape irrigation/golf course irrigation (18%), and sea water barrier (8%). Reclaimed water from large centralized systems is a significant part of the agricultural water sustainability in Arizona, Colorado, and Nevada. The WATER CONSERV II project in Orange County, Florida is one of the largest reclaimed water project where farmers have been using reclaimed water for citrus irrigation since 1986. The city of Lubbock, Texas, is another example where reclaimed water has been using for agricultural irrigation (cotton, grain sorghum, and wheat) since 1938. Therefore, non-potable water reuse appears to be, at the centralized systems scale, a newly accepted practice that will continue to grow. However, even though one in every four housing units rely upon decentralized (on-site septic) systems for their household wastewater treatment (U.S. EPA, 2007), reuse opportunities at this scale have long been overlooked due to the lack of supporting data. Currently, as much as 3.8 trillion gallons of wastewater are estimated by the authors to be treated annually by on-site and decentralized systems in the U.S. This waste load volume is comparable to that produced by 25 cities the size of New York City along with 25

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additional cities the size of Los Angeles. Decentralized technologies including on-site systems and small cluster systems are also used internationally throughout the world as permanent community-wide wastewater infrastructure components.

In addition to the apparently proven reuse approach at the large “centralized” treatment plant scale, decentralized wastewater treatment with reuse nearer the point of generation may be a beneficial wastewater reuse paradigm shift, both economically and environmentally (WERF, 2012). However, there is a lack of information about the contributions that the DWR systems can make in world water management. DWR systems can provide localized controls and will offer businesses, communities, and individual homeowners to evaluate availability of reuse water throughout the year including during emergencies where centralized systems may be interrupted. Hence, the overarching goals of this study are to:

1. demonstrate the feasibility and logistics of using DWR systems to sustain, enhance dependability and provide affordable sources of non-potable water for both rural and urban communities,

2. evaluate the technical capability of DWR systems to consistently produce non-potable quality water locally

Materials and Methods This study was conducted on the Outer Banks of North Carolina, U.S. where 85% of the housing units depend upon onsite wastewater treatment systems with a density of 299 systems/sq. mi (Pradhan et al., 2006). The remaining 15% of the housing units on the Outer Banks utilize satellite-scale decentralized wastewater treatment systems. Decentralized Water Reuse (DWR) for non-potable water supplies were studied at multiple scales ranging from the individual facility and commercial facility at the site-scale up to the satellite treatment plant at the community-scale (Pradhan and Hoover, 2009).

Five decentralized wastewater treatment facilities were chosen for this study. Three of the study sites, Pine Island Currituck Club Wastewater Treatment Plant (PICC WWTP), Kill Devil Hills Wastewater Treatment Plant (KDH WWTP) and Ginguite Woods Wastewater Treatment Plant (GW WWTP) use reclaimed effluent as a non-potable water source. The remaining two sites, First Flight Retreat Condominium (FFRC) and Nags Head Inn (NHI) are not wastewater reuse facilities. These study sites were spread along the Outer Banks from Corolla to Hatterras, North Carolina (Figure 1). The Outer Banks are home to major national heritage sites and recreational areas such as Kitty Hawk and the Wright Brothers National Memorial. They are also home to towns such as Kill Devil Hills and Nags Head, both vacation and tourist spots. Brief descriptions of the study sites are as follows.

Operators in Responsible Charge collected effluent samples biweekly and transported to the laboratory following standard operation procedures. Effluent turbidity and pH were measured daily. All effluent samples were analyzed in the North Carolina state certified laboratories.

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Figure 1: Overview of study sites (Pradhan and Hoover, 2009).

1. Kill Devil Hills (KDH) WWTP The Kill Devil Hills WWTP is a satellite-scale privately held public utility. The system serves about 475 customers associated with hotels, restaurants, small businesses and residential communities. The total design flow of the treatment plant is 500,000 gpd. Currently the utility collects and treats 35% to 40% of the plant capacity during the peak season and 15% during the off season.

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Figure 2. Process diagram for KDH WWTP plant

The plant is a typical extended aeration process (Figure 2) in which return activated sludge is being utilized for biochemical reactions for the removal of pollutants and separation of solids. All reclaimed effluent is initially stored in a low rate infiltration pond. During inclement weather, when irrigation is not allowed, the head in dosing pond raises causing infiltration into the ground water table. In addition to the pond, there are nine high rate infiltration sites to infiltrate compliant as well as non-compliant effluent, i.e. not meeting reuse water quality standard set by NCAC 02U rule. The amount of high quality effluent allowed to be disposed of in the ponds through infiltration is 136,283 gpd.

2. Pine Island-Currituck Club (PICC) WWTP Pine Island Currituck Club WWTP, a satellite-scale privately held public utility, serves about 900 customers presently and ultimately will serve about 1,100 customers. The flow rates per home ranges between 150 gpd from a retired couple on the low end to 1,800 gpd from high end rental homes which include ocean front rentals. The total design flow of the plant is 600,000 gpd.

EQ

Aeration

#1

Aeration #2

Clarifier

#1

Clarifier #2

Filter Dosing Tank

Tertiary Filter #1

Tertiary Filter #2

Reuse Dosing Tank

Non-Reuse Dosing Tank

Fish Tank

Clear Well U.V. Disinfection

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Figure 3: Pine Island-Currituck Club, process flow diagram

Treatment train for PICC WWTP is presented in Figure 3. An activated sludge treatment process is utilized followed by tertiary filtration with ultra violet (UV) disinfection. This plant operates at at high mixed liquid suspended solids (MLSS) levels (5,000 – 6,500 mg/L). A conservative design on the clarifier loading allows it to run at high MLSS levels which consistently produce high quality effluent without solids loss. In the off season when flows are down to 50,000 gpd the plant will run the MLSS level at 3,000 ppm which again produces high quality effluent and also minimizes sludge production.

3. Ginguite Woods (GW) WWTP The Ginguite Woods WWTP is also a privately held satellite-scale public utility, but serves a smaller flow consisting of wastewater from 41 two to three bedroom homes. The maximum flow this treatment plant can handle is 36,000 gpd. The treatment train of this facility is pretty much similar to that of PICC and KDH WWTP. The GW WWTP consists of activated sludge followed by tertiary filtration and disinfection utilizing chlorine tablets fed from two calcium hypochlorite tabletors. Chorine is added every other week in an attempt to maintain a 0.5 ppm chlorine concentration. This system is meeting discharge limits but does have operational challenges.

4. Nags Head Inn

Aeration 1

Aeration 3

Clarifier 1

Clarifier 2

Clarifier 3

Clarifier 4

EQ Tank

Tertiary Filter #2

Tertiary Filter #1 UV

Disinfection

Good Effluent to Golf Course

Bad Dosing to On-site Disposal

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The Nags Head Inn wastewater treatment system is a facility-scale system serving the Nags Head Inn, which consists of 100 hotel rooms, a manager’s apartment and a laundry facility. The system is designed to treat and dispose of 16,000 gpd of wastewater.

Figure 4: Nags Head Inn Process Flow Diagram

The facility consists of one 14,000 gallon 6 foot diameter lift station, two 11,600 gallon traffic rated septic tanks, an 16,000 gallon flow equalization tank, two 36/30 Bioclere trickling filters, one 4,000 gallon settling/filter feed tank, one 30” diameter sand filter and an one 1,800 gallon pump tank which discharges to a drainfield consisting of low pressure pipe (LPP) (Figure 4). The system also has two chemical feed systems which feed alkalinity and carbon into the septic tank to help nitrification/denitrification occur during the process.

Alkalinity addition is needed to facilitate microbial nitrogen conversion reaction since the drinking source water is from a community-wide reverse osmosis (RO) groundwater treatment system. These RO waters may be alkalinity limited due to the RO process. Nitrification of NH4

+ or organic NO3

- requires 7.14 milligram of alkalinity for conversion of each milligram of NH4+.

Approximately half of this alkalinity is recovered if denitrification converts the NO3- to N2 gas.

Lift Statio

Septic Tank #1

Septic Tank #2

EQ Tank

Bioclere #1

Bioclere #2

Filter Tank Pump Tank

Sand Filter

LPP Drainfield

Recycle

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The Bioclere units are fixed film trickling filters over a clarifier in a self-contained modular unit. Recirculation occurs via a clarifier return line to the septic tank. Nitrifying and denitrifying bacteria are utilized within the Bioclere units and septic tanks, respectively, to effectively complete the natural nitrogen cycle. The Nags Head Inn wastewater treatment system, in contrast to the three previous systems, is included in the study since it does not include any non-potable water reuse.

5. First Flight Retreat The First Flight Retreat is oceanfront condominium complex located in Kill Devil Hills with 35 one and two bedroom units. The wastewater treatment system for the First Flight Retreat is facility-scale system as in the prior Nags Head Inn system. The design flow of the treatment system serving this complex is 12,050 gpd.

Initial flow into the wastewater system discharges into three 12,000 gallon septic tanks in series. These septic tanks perform typical anoxic to anaerobic treatment to reduce biological oxygen demand (BOD) levels and total suspended solids (TSS). The septic tank effluent flow enters a 18,000 gallon recirculation tank from which the wastewater is dosed to an Advantex packed bed media filter. Once the water has completed a full cycle from the recirculation tank to the Advantex treatment pods several times, the water is redirected via a recirculating splitter valve. The splitter valve operates based on water level allowing forward flow only, after the water level in the recirculation tank rises to a preset level. This forward flow portion enters an anoxic tank and is dispersed onto a tire chip dispersal media bed for additional treatment. Once the effluent has traveled through the anoxic tank it is then pumped into the bottom of the media where it permeates up through the tire chips. This action is performed continuously, allowing the most substantial contact time between the wastewater and the media. The objective of the anoxic tank is to drive down oxygen levels, allowing a faster track to denitrification. Wastewater in the denitrification tank is also pumped back to one of two points in the treatment train if necessary. When water levels reach a certain point, the wastewater is then pumped from the de-nitrification tank through two 50 micron inline basket strainers to filter any sloughed biomass that may come from the growth occurring during the nitrification/de-nitrification processes. The effluent is then depressurized in an open channel and flows by gravity through a four tube UV disinfection unit and into a 5000 gallon final discharge tank. The effluent is then disposed into two separate LPP dispersal fields via center-fed manifolds.

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Packed Bed Filter

Packed Bed Filter

10% 90%

10%

50% 50%

To Drain Field

90%

Demand Pumping

Gravity Pressurized

Pressurized

Pressurized

Gravity

Recirculation Tank Low / High Oxygen Environment

Septic Tank Low Oxygen Environment

Anoxic Tank Low Oxygen Environment

Dose Tank

Figure 5: AQWA Inc. process flow diagram at First Flight Retreat

This fifth, and final, study site does not utilize non-potable reuse. It is included in the study, just like the Nags Head Inn, to serve as a contrast to the three DWR study sites at Kill Devil Hills, Pine Island Currituck Club and Ginguite Woods.

Results and Discussion

In order to reduce use of drinking water for non-potable uses water we need to find sustainable sources of water for non-potable uses. Results obtained from this research study conducted from January 2007 to July 2009 are analyzed and presented here to provide insight on possibilities of decentralized wastewater reuse as non-potable water sources for rural and urban communities. Study findings are presented and discussed under the following three broad headings:

1. Technology function and performance Functionality and performance of technologies were measured in terms of effluent quality produced at all study sites. Study results along with the North Carolina reuse standard and national EPA guidelines are presented in Table 1.

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According to 2012 EPA guidelines 90% of the states in the U.S. have reuse water regulation and/or guidelines. The EPA has categorized the types of reuse as urban reuse (unrestricted and restricted), agricultural reuse, recreational impoundments, environmental reuse, industrial reuse, groundwater recharge and indirect potable reuse. However, there is no regulation of reclaimed water at the federal level. Instead this non-potable type of water supply is exclusively regulated at the individual state level.

North Carolina uses reclaimed water for unrestricted urban reuse, restricted urban reuse and industrial reuse. Unrestricted urban reuse includes areas where public access is not restricted such as parks, playgrounds, school yards and residences and may be used for toilet flushing, air conditioning, fire protection, construction, ornamental fountains and landscape or aesthetic impoundments. Urban reuse requires a high degree of treatment, i.e. a minimum of secondary treatment and additional treatment with disinfection prior to effluent delivery to the intended areas. In addition, recent changes in NC reclaimed water regulation now allow reclaimed water use in agricultural applications, especially with Type 2 reclaimed water (NCAC, 2011). Type 2 reclaimed water is a tertiary quality effluent (filtered or equivalent) that must have gone through dual disinfection system containing UV disinfection and chlorination or equivalent dual disinfection process to meet pathogen control requirement.

Throughout the study period, the BOD5, ammonia, TSS, pH and turbidity levels in reclaimed water from the KDH study site complied with the North Carolina regulations 95-99.9% of the time, depending upon the parameter. In the case of fecal coliforms, 4% of the data were outside of the water quality standard limits. During 2007, the fecal coliforms varied from the range of non- detectable levels to 5 colony forming unit (cfu) per 100 ml, except one data point with 17 cfu. However, this was still within the required state limits. Fecal coliforms in reclaimed effluent varied from non-detectable levels to 5 cfu per 100 ml except for 4 data points: one in June, two in August and one in November in 2008. Only 0.2% of the data points during the 2007-2009 study periods exceeded the daily maximum limit.

Parameters tested in reclaimed effluent from the PICC site complied with reclaimed water quality standard 100% of the time, except TSS. Only one data point in 2007 exceeded the maximum allowable level in the case of TSS at PICC site.

The Ginguite Woods WWTP is a much smaller DWR system compare to PICC and KDH. Ammonia and pH level in the reused water produced by this facility were within the state’s allowable level throughout the study period. In case of BOD5, TSS, and turbidity, few data points were higher than maximum daily allowable level but monthly averages were within the limit. On November 30, 2007, turbidity level was measured 144 NTU, however the day before and after that day turbidity in reused water was 3.4 NTU. In 2007, fecal coliform level complied with reuse water quality standard 100% of the time. Fecal coliforms in reclaimed effluent varied from non-detectable levels to 590 cfu per 100 ml in Nov 30, 2008. The Fecal coliforms levels in the reused water collected before and after data sampling date were below detection limit.

The results indicate that all three treatments plants are continuously producing high quality effluent suitable for unrestricted urban applications. The supply of non-potable water from DWR systems are reliable and the demand increases with population growth.

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Table 1: Reuse water quality from three DWR systems.

See attached document

* Average = Geometric mean, ND = below detection level, NA = not applicable.

Development and use of pre-engineered decentralized reuse technologies is currently limited. This results from the profusion of numerous and varied requirements for different states in the U.S., especially the required water quality treatment levels and methods for decentralized reuse technologies. Hence, national sanitation foundation (NSF) International developed American National Standard through ANSI (the American National Standards Institute) for decentralized water reuse systems with design flows in the range of approximately 400 to 10,000 gpd. The national standards, NSF/ANSI Standard 350 On-site Residential and Commercial Water Reuse Treatment Systems and NSF/ANSI Standard 350-1 Onsite Residential and Commercial Graywater Treatment Systems for Subsurface Discharge (NSF, 2011a and 2011b), provide water quality treatment requirements and test methods to certify decentralized technologies that can achieve those treatment standards for water reuse as non-potable water supply. The authors are involved in this effort and anticipate that the establishment of national decentralized reuse standards will facilitate technology development and implementation at the small individual facility scale, both nationally and internationally as well.

This variability in reclaimed water requirements does not inhibit design and testing of individual, large centralized reclaimed water treatment plants to see if they these local specifications. The same is also true for the large decentralized treatment plants with design flows exceeding 50,000 gpd. But the same is not true for the smaller scale decentralized reuse systems. This limitation is particularly evident for those reuse techniques used to serve smaller communities (small neighborhoods) with smaller design flows at less than 5,000 to 10,000 gpd. While decentralized wastewater treatment systems at this scale occur throughout the North Carolina Outer Banks, they have not been utilized as decentralized treatment systems for reuse to enhance non-potable water supplies. Similarly, decentralized wastewater treatment systems occur extensively throughout this area of the NC Outer Banks. None of these systems are used to provide non-potable waters locally at the small individual facility scale (e.g. homes, small businesses).

2. Usage of reclaimed water Current practices of reclaimed water usage include urban reuse, agricultural reuse, impoundments, environmental reuse, industrial reuse, potable reuse (Guidelines for wastewater reuse, 2012). However, reuse of reiterated effluent from all three DWR systems in this study is limited to urban usage only (Table 2).

Table 2: Wastewater reuse scenario in Outer Banks of N.C.

Facility Name /Type Type of Reuse % Used Scale of systems 1. Pine Island-Currituck Club WWTP Resort; golf course community with two hotels and small commercial

Surface irrigation of golf course & common grounds; water features

100%

Large-scale multi-subdivision development; satellite-scale

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2. Kill Devil Hill WWTP Resort; residential and commercial resort community

Surface irrigation of common grounds; water features

2-22%

Large-scale subdivision & commercial district; satellite-scale

3. Ginguite Woods Residential development with 2 and 3 bedroom homes

Surface irrigation at individual homesites and common areas

100% Medium-scale development; satellite-scale

4. Nags Head Inn Hotel with 100 rooms bedrooms units

No reuse

NA

Facility-scale

5. First flight Retreat Condominium complex with 35 one and 2 bedroom units

No reuse

NA

Facility-scale

One hundred percent of the reclaimed wastewater from the Pine Island Currituck Club WWTP was used to irrigate 66 acres of the Currituck Club golf course. The golf course is vegetated primarily by Bermuda grass and it actually has two irrigation systems. Reclaimed wastewater is not utilized for the golf tees, greens and areas where setbacks to estuaries would not allow use of reclaimed effluent. The treated effluent is utilized for irrigation of fairways and the driving range at the golf course. Non-compliant effluent, produced less than one percent of the time, is managed through use of a high rate disposal spread bed and an infiltration pond.

Our study indicated that for places like Pine Island which is surrounded by salt water, the natural groundwater system is susceptible to water quality and salt water intrusion issues. Those issues can cause degradation of the groundwater quality and cause irrigation problem. For the places like this, treated effluent is better source of irrigation water, not the groundwater wells, because it is the product of a regulated drinking water supply, has a more consistent quality than the “fresh” groundwater irrigation system. As a result of which residents in this subdivision prefer using reclaimed effluent, over groundwater, for irrigation of their lawns as well. This subdivision has been using decentralized reclaimed effluent to good effect for the last 15 years. Reclaimed effluent demand outpaced the supply consistently in this community. This unbalanced supply and demand issue can be overcome to some extent by integrating storm water in the wastewater treatment plant.

Another generator of reclaimed water, the Kill Devil Hill WWTP, produces approximately 50 million gallons of reclaimed effluent per year. This reclaimed effluent was used to irrigate 2.5 acres of lawn covered with turf grass and 6.3 acres of landscapes as well as to fill a supply pond (48,979 ft2) containing ornamental water fountain. All irrigation sites are located within the Bermuda Bay subdivision. Reclaimed effluent usage in this subdivision was very low compared to the Pine Island WWTP. In 2007, 2008 and 2009 the reclaimed effluent was used 22%, 13% and 2%, respectively. Lower usage of reclaimed water in this subdivision may be due to reclaimed water being used to irrigate only eight acres of land. The remaining high quality effluent which complied with the state non-restricted urban use standard was disposed through a low rate infiltration pond. Substantial amounts of high quality potable water can be saved by using all reclaimed effluent for various non-potable uses. This extra reclaimed effluent can be used for different purposes such as personal vehicle washing, toilet flushing, and firefighting or provided to adjacent subdivision for their non-potable usages.

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The Ginguite woods WWTP generated about 2.6 million gallons of treated effluent per year. One hundred percent of the wastewater generated was reused for surface irrigation at individual homesites and common areas within subdivision.

The purpose of this article is not to provide complete economic analysis. However, it is useful to realize the potential economical values. For instance about 54 million gallons of reclaimed effluent per year had been used for non-potable water uses from the PI WWTP alone. In other words, this treatment plant conserved approximately 54 million gallons of high quality, energy intense drinking water per year, which equates to a savings of approximately $530,280 (drinking water cost = $3.28/1000 gallon and sewer cost = $6.54/1000 gallon) compared to traditional water use patterns. Clearly, this is not a complete analysis. The cost to treat and move the water for reuse would also need to account for direct comparison. Other additional cost would be tertiary filtration, continuous monitoring of turbidity and disinfection.

3. Missed opportunities Effluent quality from on-site wastewater treatment systems serving the First Flight Retreat oceanfront condominiums and the Nags Head Inn were studied. Neither of these sites were equipped with effluent reclaim facility. However, effluent from both of these sites complies with state non-potable water reuse standards with the exception of fecal coliforms in the First Flight Retreat effluent (Table 3). With a small effort, effluent from these study sites could meet reuse water standard, and could be used for lawn irrigation, landscaping, vehicle washing, and toilet flushing. Design flows for the Nags Head Inn and the First Flight Retreat were 11,600 gpd and 12,000 gpd respectively. Even with 50% occupancy, each facility could save about two millions gallon of high quality, drinking water per year.

The data for the First Flight Retreat and Nags Head Inn facilities are provided to emphasize the loss of a substantial decentralized reuse opportunity. Portable water is a precious resource at the North Carolina Outer Banks with few local sources other than via very expensive, energy intensive and waste producing water treatment methods like reverse osmosis.

Table 3: Effluent quality from the facilities not designed for reclaimed effluent.

Parameters First Flight Retreat Nags Head Inn BOD5 (mg/L) < 2 2.09 TSS (mg/L) 2.15 1.53 NH3 (mg/L) 2.35 0.41 TN (mg/L) 10.4 17.21 Fecal (cfu/100ml) 45 5.27 Turbidity (NTU) 0.8

Conclusions

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Decentralized wastewater reuse as an alternative to using portable water for non-portable usage is a sustainable, dependable and affordable water supply method for rural and urban communities. Use of reclaimed effluent can reduce demands on drinking water supplies by providing a mean for local decentralized water supplies for meeting non-potable needs in communities. This approach can facilitate the accelerated and sustainable extension of environmentally responsible wastewater services. It offers great potential for cost reduction, accommodates the necessary domestic water conservation efforts, reduces freshwater inputs in wastewater transportation thus eliminating unnecessary demand on freshwater and reduces associated environmental risks. In light of this, potential public health impacts of non-potable decentralized water reuse are not fully understood at this time. Research studies that develop strategies for the design, management, and use of decentralized water reuse in ways that minimize or eliminate any potential negative health effects are recommended. In addition, the lack of national and international standards for decentralized wastewater reuse has limited reuse technology development and adaption. This is particularly of importance in the case of the lower daily flows systems serving individual sites and small commercial facilities, and small communities. New national decentralized wastewater reuse standards currently being developed by NSF International can help address this issue to some extent.

Literature Cited AP big story, 2015. When the wells run dry: California families cope in drought, http://bigstory.ap.org/article/bff68e2001424f73aa51b0690520535d/when-wells-run-dry-california-families-cope-drought

Asano, T. et. al., 2007. Water reuse: issues, technologies and applications. Metcalf and Eddy, Inc. USA

Bahri, A. et al., 2001. Reuse of reclaimed wastewater for golf course irrigation in Tunisia. Water Science and Technology, Vol 43 No10 pp 117–124.

Bryk, J., R. Prasad, T. Lindley, S. Davis, and G. Carpenter. 2011. National Database of Water Reuse Facilities: Summary Report. WateReuse Foundation. Alexandria, VA.

Florida Department of Environmental Protection (FDEP). 2011. 2010 Reuse Inventory. Florida Department of Environmental Protection. Tallahassee, FL. Retrieved October 2015 from <http://www.dep.state.fl.us/water/reuse/inventory.htm>.

Grinnell, G. K., and R. G. Janga. 2004. Golf Course Reclaimed Water Marketing Survey. American Water Works Association. Denver, CO.

House, C.H., 1999. Combining constructed wetlands and aquatic and soil filters for reclamation and reuse of water. Journal of Ecological Engineering, Vol 12, pp 27-38.

Kenny, J. F., N. L. Barber, S. S. Hutson, K. S. Linsey, J. K. Lovelace, and M. A. Maupin. 2009. “Estimated Use of Water in the United States in 2005.” United States Geological Survey (USGS). Retrieved on June 23, 2015 from http://pubs.usgs.gov/circ/1344/pdf/c1344.pdf

North Carolina Administrative Code (NCAC). 2011. North Carolina Reclaimed Water Regulations. 15A NCAC 02U. Retrieved on August 3, 2015 from http://ncrules.state.nc.us/ncac/title%2015a%20%20environment%20and%20natural%20resource

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s/chapter%2002%20%20environmental%20management/subchapter%20u/subchapter%20u%20rules.html

National Research Council (NRC). 2012. Water Reuse: Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater. The National Academies Press: Washington, D.C.

NSF/ANSI 350-2011 (NSF). 2011a. Onsite Residential and Commercial Water Reuse Treatment Systems. National Sanitation Foundation, Ann Arbor, Michigan, July 2011. NSF/ANSI 350-1-2011 (NSF) 2011b. Onsite Residential and Commercial Graywater Treatment Systems for Subsurface Discharge. National Sanitation Foundation, Ann Arbor, Michigan, June 2011.

Ogoshi, M. et al., 2001. Water reuse in Japan. Water Science and Technology, Vol 43, No 10 pp17-33.

O’Neill, M. P. and J. P. Dobrowolski. 2011. “Water and Agriculture in a Changing Climate.” HortScience. 46:155.

Pradhan, S., and M.T. Hoover, 2009. Outer Banks Decentralized Water-Wastewater Reuse Workshop: Field Tour Guide. Published by the Soil Science Department, College of Agriculture and Life Sciences, North Carolina State University and North Carolina Cooperative Extension.

Pradhan, S., M. T. Hoover, R. E. Austin, and H. A. Devine., 2007. Potential Nitrogen Contributions from On-Site Wastewater Treatment Systems to North Carolina’s River Basins and Sub-basins. NC Agricultural Research Services, NCSU. Technical Bulletin 324. Retrieved on May 31, 2015 from http://www.soil.ncsu.edu/publications/TB324Finalmay29.pdf

U.S. Environmental Protection Agency (EPA). 2012. Guidelines for Water Reuse. 600/R-12/618. Environmental Protection Agency. Washington, D.C.

U.S. Environmental Protection Agency (EPA), 2009. Septic system fact sheet. Retrieved on August 6, 2015 from http://www.epa.gov/owm/septic/pubs/septic_systems_factsheet.pdf

U.S. Environmental Protection Agency (EPA). 2004. Guidelines for Water Reuse. 625/R-04/108. Environmental Protection Agency. Washington, D.C.

World Health Organization and UNICEF Joint Monitoring Programme (JMP). (2014). Progress on Drinking Water and Sanitation, 2014 Update

Water Environment Research Foundation (WERF). 2012. “When to Consider Distributed Systems in an Urban and Suburban Context.” Retrieved July 2015 from http://www.werf.org/i/c/Decentralizedproject/When_to_Consider_Dis.aspx#table>.

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Parameters/ Statistics

KDH WWTP PI WWTP GW WWTP NC Rule EPA 2007 2008 2009 2007 2008 2009 2007 2008 2009 Type 1 Guidelines

1.BOD5 (mg/L

Monthly avg. ≤10 Daily max. 15 ≤ 10

(Avg) 1.14 1.72 1 1.29 1.33 1 3.14 4.37 2.74

Stdev. 0.85 2.81 0 0.69 1.19 0 2.67 5.82 4.34

Min. <2 ND <2 ND ND 1 ND ND ND

Max. 6 15 <2 3 6 1 8 24 18

2.TSS (mg/L)

Monthly avg. ≤ 5 Daily max. 10 NA

(Avg) 0.61 0.71 0.56 4.11 0.88 1.29 3.87 2.84 2.33

Stdev. 0.35 0.62 0.22 13.12 0.63 1.04 4.69 2.73 3.30 Min. <1 <1 <1 ND <1.0 <1 ND ND ND

Max. <2 3.3 <1.3 55 2.1 3.6 13 8 13

3.NH3 (mg/L)

Monthly avg. ≤ 4 Daily max. 6 NA

(Avg.) 0.07 0.13 0.22 0.37 0.23 0.22 3.24 1.06 1.31 Stdev. 0.08 0.11 0.41 1.14 0.45 0.31 3.16 1.86 2.94

Min. <0.1 <0.2 <0.2 ND ND <0.2 ND ND ND

Max. <1.0 0.6 1.6 4.8 2 1.1 8.5 6.7 10.7

4.Fecal (/100ml)

Monthly avg. ≤ 14 Daily max. 25

Weelkly avg. Non-detectable fecal/100ml ≤ 14 cfu in all samples

(Avg)* 0.8 1.2 0.6 1.1 0.5 0.7 0.7 1.6 1.6

Min <1 <1 <1 ND <1 0.5 ND ND ND

Max 17 83 1 7 1 8 3 590 200

5.Turbidity (NTU)

≤10 Weekly avg. ≤ 2 should not exceed 5 any time

(Avg) 0.62 0.6 0.5 1.6 1.3 1.5 5.01 2.46 1.99

Stdev. 0.29 0.3 0.08 0.56 0.32 0.43 16.00 3.90 1.89 Min. 0.35 0.33 0.25 0.21 0.73 0.93 1.58 0.70 0.47

Max. 2.02 5.68 0.67 4.39 3.2 3.43 144.80 58.72 14.31

6.pH (Standard Unit) Min

6 to 9 6 to 9 6.81 7 6.65 6.8 6.7 6.6 5.9 6 5.9 Max 7.65 7.85 7.36 7.9 7.5 7.3 6.8 7.3 7.2

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