A POTABLE REUSE DEMONSTRATION SCALE PROGRAM IN EAST COAST FLORIDA

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1 A POTABLE REUSE DEMONSTRATION SCALE PROGRAM IN EAST COAST FLORIDA Jennifer C. Roque, Tetra Tech, 201 East Pine Street, Suite 1000, Orlando, FL Ph: Brian Foulkes, Tetra Tech, Orlando, FL, Andrew Woodcock, Tetra Tech, Orlando, FL, Jarrett Kinslow, Tetra Tech, Orlando, FL ABSTRACT The implementation of direct potable reuse (DPR) in recent years has become a necessity in drought-driven states such as California and Texas. However, in Florida, alternative water supplies have long been established for providing reclaimed water to end users for irrigation and other nonpotable applications. Furthermore, the driver for investigation of DPR in the state of Florida has been circulating around increased regulations for the protection of its precious resources. Surface waters, a common disposal site for treated wastewater, and groundwater sources, which have limited supply, are facing increased regulatory protection regarding Minimum Flows and Levels (MFLs) and Total Maximum Daily Loads (TMDLs) for nutrients. The City of Daytona Beach (City), located on the east coast of Florida, currently discharges their excess reclaimed water to the Halifax River, mainly when it is in excess of customer reclaimed water demands. In 2010, a portion of the river was designated as an impaired water body and a TMDL for nitrogen was established. The City is now reconsidering their disposal practices by investigating the feasibility of a DPR Demonstration Testing System (DTS), which will treat reclaimed water to meet or exceed drinking water standards. The Demonstration Testing System, which has been successfully co-funded by the St. Johns River Water Management District (SJRWMD) Cost Share Program, will demonstrate the purification of reclaimed water using a full advanced treatment (FAT) process. The FAT process will consist of reverse osmosis (RO), ultrafiltration (UF), and advanced oxidation with ultraviolet light (UV- AOP) using full scale equipment for the simulation of a full scale facility at a lower production capacity (0.20 million gallons per day, MGD). Final design for the Demonstration Testing System has been completed and the construction and operation of the facility will provide invaluable insight to pursuing alternative solutions for addressing water quality and groundwater withdrawal issues with one innovative solution. INTRODUCTION The state of Florida s beaches and marine environment are world-famous, and a major driver of tourism, migration, and economic activity in its coastal communities. In 2013, the State of Florida was home to approximately twenty million residents, making it the third largest state in the United 1

2 States. With population growth, potable groundwater supplies in Florida are becoming limited, and for new water supplies, opportunities are becoming increasingly difficult to economically treat and permit. Additionally, natural resources, such as river basins, are becoming more heavily influenced by nutrients from among other sources, such as wastewater effluent. Eastern Volusia County, the heart of Daytona Beach, has experienced a rapid increase in population and economic growth over the past few decades, and as a result, there has been an increase in demand for potable water, and a corresponding increase in nutrient discharges to local water bodies. One of the primary sources for effluent disposal in Volusia County is the Halifax River, a 23-milelong tidal estuary located on the Atlantic Coast near the City of Daytona Beach. The upper portion of the Halifax River, an effluent discharge point for the City s local wastewater treatment facilities (WWTF), has been verified as an impaired water body by the state of Florida, and has been included on the Verified List of Impaired Waters for the Upper East Coast Basin, which was adopted by the Secretarial Order in The City has since begun to investigate alternatives for treating their wastewater effluent to a higher level, in order to reduce nutrient discharges to the river while preserving potable water resources. Other alternative water supplies, such as seawater, brackish groundwater, surface water, and storm water can provide additional sources of water for growing communities. Although seawater desalination has become a technically-viable option for coastal communities with water shortages, the implementation of desalination is accompanied with high capital construction costs and annual operating expenses, along with a difficult permitting process that has kept this alternative water supply out of the forefront. Additionally, increased regulatory pressures for effluent disposal of treated wastewater have pushed treatment levels for municipal wastewater closer to drinking water quality more than ever before. The City has begun to explore alternative water supply treatment options for their effluent discharge, one option being potable reuse. Potable reuse allows the City to preserve natural water supplies and generate a water supply that is augmented by population growth. Potable Reuse Potable reuse, a concept which purifies highly treated wastewater to a quality equal to or superior to drinking water quality standards, provides an additional source of supply that is available with a growing population. Direct potable reuse (DPR), introduces highly treated effluent directly into a raw water supply upstream of a water treatment facility (WTF). Communities experiencing substantial population and economic growth, such as Georgia and Florida, are only just beginning to explore the concept of indirect and direct potable reuse for sustainable water resource management practices, even though the concept of potable reuse has been around for nearly 50 years, with early groundwater recharge (IPR) programs in California, and DPR in Windhoek, Namibia. Even though exposure to this concept has gained popularity within the professional water community, public support has been slow to advocate these advances in technology. However, with rapid advances in treatment and monitoring technologies, coupled with the urgent need for new water supplies and more stringent effluent discharge limits, potable reuse has become an increasingly feasible technology. 2

3 PURPOSE OF PROJECT A consideration for the City in regards to discharging excess reclaimed water to the Halifax River are the impaired water body regulations that are currently being implemented by the United States Environmental Protection Agency (USEPA) and the Florida Department of Environmental Protection (FDEP), in regards to nutrient concentration limits that can be discharged to the Halifax River. When the Basin Management Action Plan (BMAP) is developed, the City will have already needed to invest in the design, construction and operation of supplementary nutrient removal facilities. In addition to compliance with foreseen BMAP criteria, current initiatives around the state of Florida, such as the Central Florida Water Initiative (CFWI) are stating that the current groundwater supplies have been maximized to their full potential. Potable reuse seems to provide a dual benefit to the City by addressing both of these issues with one solution. In order to implement a concept such as direct potable reuse, confidence and reliance are required on the applied technologies to produce a drinking water source that is safe, meets all applicable regulatory standards and is acceptable to consumers. Therefore, the Demonstration Testing System will investigate and provide real time data of treatment of the City s wastewater effluent to a high level of quality, and will also provide the size, types of facilities, and costs associated with conduction a demonstration test of this concept. The Demonstration Testing Program developed herein presents a two (2) year testing program of a full advanced treatment (FAT) train using full scale equipment for the treatment of reclaimed water to potable water standards. The demonstration facility will be located at the City s Westside Regional Water Reclamation Facility (WRWRF) and adjacent to the City s Ralph Brennan Water Treatment Facility (WTF). A portion of the WRWRF s treated reclaimed water will be diverted to the demonstration facility where it will pass through the FAT process. The product water will be tested for a number of water quality parameters to document operational parameters and verify treatment efficiency. After treatment, the product water and other waste streams will be transferred back to the headworks of the WRWRF for retreatment with the possibility of also blending with the City s reuse water. The demonstration facility will have a product water capacity of 200,000 gallons per day (GPD) and will require approximately 260,000 GPD of treated reclaimed water from the WRWRF to account for efficiency losses. TIE-IN WITH EXISTING WATER RECLAMATION FACILITY The tie-in point of the demonstration facility to the WRWRF process was predicated upon obtaining a reclaimed effluent water supply with a consistent quality and pressure whilst having minimal impact on the normal operations of the WRWRF. As part of the existing WRWRF process, high level disinfection treatment requirements are currently being met by the use of granular media filtration followed by disinfection with ultraviolet (UV) radiation. The absence of chlorine as a disinfection agent provides flexibility in selecting the influent tie-in point for the demonstration facility. The effluent water leaving the UV disinfection basins flows by gravity to a transfer pump station, which pumps water through a 36-inch pre-stressed concrete cylinder pipe (PCCP) to the distribution box, which acts as a flow-through basin as chlorine is no longer utilized. The effluent 3

4 water flows over a weir, through the tank, over an effluent weir, and then to the 5.0 million gallon (MG) circular concrete reclaimed storage tank (RST). The RST provides daily storage to balance the supply of treated reclaimed water with reuse system customer demands. The tank has two (2) effluent pipelines. One (1) 36-inch PCCP supplies the City s high service pump station, which meets the on-demand high pressure (85 to 110 psi) needs of customers in the western part of the service area, as well as pressurizes the in-plant non-potable water system piping. The second pipeline, a 42-inch PCCP, leads to a control valve assembly which modulates to partially open for supplying gravity flow to a 42-inch PCCP outfall pipeline. During the peak irrigation season, the RST can be temporarily depleted, necessitating shutdown of the LPGA Pump Station. The RST is also used for supplying reclaimed water in emergency scenarios. Occasionally, conditions in the treatment process occur such that the WRWRF must go in reject mode, in which reclaimed effluent from the WRWRF s treatment process is diverted through a system of control valves to the WWTF s 42-inch river outfall pipeline for disposal. To supply a 200,000 gallon per day (gpd) demonstration facility, a 12-inch pipeline to the facility is proposed to connect to the reclaimed effluent of the WRWRF. Based on a review of the drawings and site visits to the WRWRF, a suitable connection point for drawing reclaimed effluent water to feed the demonstration facility has been identified at their existing distribution box (formerly a chlorine contact chamber). The existing distribution box has two (2) basins with drain lines connected to the bottom of each basin. One advantage of this tie-in point is that it avoids tapping any existing WRWRF reclaimed effluent piping. Additionally, the distribution box also provides a storage volume with a relatively constant feed pressure to the demonstration facility. Discharge Piping The demonstration facility will produce approximately 200,000 gpd of product water and 60,000 gpd of concentrate water. The product and concentrate water will be combined and either recycled back to the headworks of the WRWRF using a pump station, or sent to the reuse storage tank if reuse water quality standards are met. DEMONSTRATION TESTING FACILITY Selection of the capacity of the treatment process was determined by a number of factors including: The use of full scale treatment equipment to simulate, to the most economical extent possible, full scale operations, Incorporation of two (2) process trains each for the membrane processes to allow the facility to operate during cleaning and backwash cycles, and The most economical configuration with regards to higher capacity to minimize overall project costs. After discussions with original equipment manufacturers (OEMs), it was determined that an overall facility product water capacity of 200,000 gpd addresses these factors. The demonstration facility will include chemical and screening pretreatment and three (3) main purification processes. Screening will aid in removing large particulates and pretreatment using chlorine and ammonium sulfate will serve to provide a disinfection residual using chloramines, for extension of membrane 4

5 life and to minimize fouling. The main purification processes will include UF, RO, and AOP consisting of UV disinfection with hydrogen peroxide. A summary of the design capacities for the major treatment processes is provided in Table 1. Table 1. Demonstration Facility Design Capacity Overview Process Component Reclaimed Water Supply Capacity UF Treatment Capacity (at 95% recovery) RO Treatment Capacity (at 80% recovery) Purified Water Capacity Average Flow Capacity 0.26 MGD (181 gpm) 0.25 MGD (174 gpm) 0.20 MGD (139 gpm) 0.20 MGD (139 gpm) Treatment equipment within the building will include two (2) ultrafiltration (UF) skids at 120,000 gpd capacity each, two (2) reverse osmosis (RO) skids at 100,000 gpd capacity each, and an ultraviolet-advanced oxidation process (UV-AOP) reactor system each with associated equipment, pumping skids and chemical systems to complete the FAT train. An equalization tank has been incorporated for balancing flow variations from the UF skids prior to entering the RO process. An operator area was also incorporated for storing operator supplies, testing reagents, collection logbooks, personal protective equipment (PPE), and laboratory supplies. Additionally, eyewash stations, potable water stations and testing areas have been included in the design. Process Description The product water from the demonstration facility is anticipated to meet or exceed all current potable water standards and will be tested for a variety of microconstituents and pharmaceuticals and personal care products (PPCPs). It has been designed to include an advanced 3-stage treatment process (FAT), a process that has been widely proven in potable reuse projects around the country. As shown in Figure 1, the FAT process consists of a UF, RO and UV-AOP stage. Membrane filtration provides initial removal of suspended solids and virus and pathogen removal. It also acts as a solids barrier for the RO stage, which extends the life of the RO membranes. The RO stage provides an additional barrier for virus and pathogens, as well as removes a majority of organics, inorganics, heavy metals, bacteria and personal care products. The AOP process, the third stage of the process, provides an additional barrier against viruses, nitrosodimethylamine (NDMA) and reduces trace levels of low-molecular-weight organics, constituents that pass through the membrane stages. The demonstration facility will be designed to produce product water based on a 94-percent recovery for the UF process and an 80-percent recovery for the RO process. The process flow diagram is generally shown in Figure 1. 5

6 To Public Access Reuse To Pump Station Backwash/CIP Waste Figure 1. Purification Treatment Process Flow Diagram The purified water and demineralized concentrate will be evaluated to assure compliance with public access reuse requirements prior to being sent to the WRWRF s existing reclaimed storage tank (RST). If the combined reuse water does not meet reuse standards, it will be combined with other residual waste flows generated during plant start-ups and operation as well as membrane backwashing and cleaning operation flows, and will be routed to a waste recycle pump station that will convey these waste streams to the headworks of the WRWRF. Membrane Filtration (UF) UF membrane technology is typically applied to water purification processes for the removal of colloidal particles such as dissolved silica, viruses and small particles larger than 0.01 micrometer (μm). The UF membranes are composed of hollow fibers that separate these particles from water by a sieving mechanism through dead-end flow filtration. In dead-end flow filtration, the feed water is passed entirely through the membrane and impermeable substances are allowed to gradually accumulate on the membrane surface. UF systems typically include: Strainers to protect the membrane elements from damage from abrasive materials, such as sand or grit, A pressurized or submerged hollow-fiber membrane system, Filtrate pumping, A backpulse system for periodic backwashing of the membrane elements, and A membrane cleaning system. Membrane Separation (RO) RO is a membrane-based process used to separate dissolved solids, including ions, trace organics, and most other chemical compounds from solution. Thin film composite membranes are commonly used in water treatment as they provide high rejection rates at low operating pressures. RO systems typically include: 6

7 An equalization tank for balancing fluctuations in flow from the UF system to the RO system, A chemical pretreatment system including Ph adjustment with sulfuric acid and antiscalant (scale inhibitor), Cartridge filtration, Membrane high pressure pump and interstage boost pump, Two-stage RO membrane system, and A membrane cleaning system. UV Disinfection and Advanced Oxidation (UV-AOP) The AOP will consist of UV disinfection with hydrogen peroxide (H2O2) addition upstream of the UV lamps. The UV disinfection process provides additional disinfection through inactivation of microbes at germicidal wavelengths of UV light. The UV light also interacts with H2O2 to transform it into hydroxyl radicals (OH ), which function as powerful oxidizing agents that destroy most trace organic compounds. The AOP also provides significant removal of brominated trihalomethanes (THMs). The UV disinfection treatment process will utilize low pressure high output (LPHO) amalgam UV lamps, operated at constant output. Each UV lamp is separated from the water inside a quartz sleeve. Dilute hydrogen peroxide will be injected using a peristaltic pump. AOP systems typically include: Hydrogen peroxide feed chemical equipment, and A UV light reactor. BASIS OF DESIGN A unique criteria for the basis of design of the demonstration facility will include the testing and operation of different membrane manufacturers. The UF process will test up to four (4) different membrane modules, each for a length of time sufficient to collect enough data for observation of performance at different set points. The RO process will test up to three (3) different membrane elements, and one (1) nanofiltration (NF) element. Each different module or element will be tested with the same criteria and design set points for equal evaluation during the demonstration testing period of two (2) years. Ultrafiltration (UF) Process The UF process consists of low pressure-driven membranes for the separation of materials from the source water. The UF process is mainly automated and will have low operational labor requirements. The system, however, will require routine cleaning, including standard and chemically enhanced backwashes (CEBs). Occasionally, the system will require manual clean-inplace (CIP) operations to be carried out. The reclaimed water flows through the modules in an outside-in method, where the flow enters through the outside of the fibers and is filtered radially inward through the fiber wall. Filtrate is then collected from a center tube. The UF system will include two (2) UF skids, each rated at a nominal capacity of 90.3 gpm. The average membrane flux was determined from manufacturer recommendations. Design criteria for the UF system are provided in Tables 2 and 3. 7

8 Table 2. UF Treatment Units Design Criteria Parameter Value Feed Water Capacity (Total/per Skid) 181/90.3 gpm Filtrate Recovery Rate 95% Filtrate Capacity (Total/per Skid) 174/87 gpm Average Waste Flow 7 gpm Minimum/Maximum Feed Water Temperature 20/30 Degrees C Table 3. UF Treatment Skids Design Criteria Parameter Value Number of Skids Two (2) Number of Membrane Modules (each skid) Five (5) Average Membrane Flux 35 gallons per square foot-day (gfd) Membrane Area per Skid 3,875 square feet Reclaimed water is first dosed with sodium hypochlorite (NaOCl) and ammonium sulfate ((NH4)2SO4) to form monochloramines prior to the flow being split between two (2) UF pumps, which are skid mounted along with the automated strainers. Each skid can be isolated if membranes need to be taken off-line for repairs, replaced or for maintenance. Each skid will have an air scour supply that is manifolded with a membrane integrity test (MIT) air valve control line and will be monitored for pressure. The skids will also have individual (clean-in-place) CIP return/feed lines to a dedicated CIP tank, to the drain pump, and from the backwash pump, which manifold into the CIP return/feed line for ease of operation. The backwash system will typically initiate an automatic cleaning cycle for each skid after anywhere from 20 to 60 minutes of forward filtration. The backwash cycle has a duration of approximately 3 minutes, before the unit goes back into forward filtration. The backwash process will include an air scour across the membranes to help dislodge particles attached to the membrane surface. The backwash system is fed by the UF backwash tank, which is supplied with UF filtrate. The backwash tank then transfers the filtrate water through a strainer, where it is fed to the UF skids. Even with effective pretreatment and frequent backwashing, the UF membrane modules can experience gradual fouling over time. Fouling has a significant effect on membrane performance and can reduce process efficiency by requiring a higher feed pressure or causing a reduction in filtrate production. The membrane cleaning system will include chemicals such as citric acid, sodium hypochlorite, hydrochloric acid, sodium hydroxide and sodium bisulfite. A chemically enhanced backwash (CEB) are termed maintenance cleanings, which can occur on a daily or weekly basis. A CIP operation is typically manually performed and are implemented to restore the condition of the membrane modules if fouling in the system significantly alters the normal operating pressure or filtrate production. Each skid is designed to contain independent cleaning systems and piping, including a mixing tank. The equipment is sized to provide the required flow rate to clean the entire skid at once. 8

9 Reverse Osmosis (RO) Process The RO system utilizes low pressure membranes to remove over 95% of chlorides, sodium and total dissolved solids (TDS), as well as high removal of various microconstituents and naturally occurring organics that may pass through the UF process. The thin film composite membranes provide high salt rejection at low operating pressures, and purify the water to a near-distilled quality. The membrane skids are arranged in parallel and will consist of 2-stages where the concentrate in the first stage is fed to the second bank of membranes to increase system recovery. Each skid is designed to operate at a fixed capacity and is comprised of spiral wound membrane elements that provide approximately 400(+/-) square feet of membrane area per element. The membrane elements are housed in fiberglass pressure vessels that are arranged in parallel with common feed water, product water (permeate) and concentrate water piping. These sections of pressure vessels are designed to allow isolation for maintenance and cleaning. UF filtrate water will flow to an RO feed equalization tank prior to the RO skids, where it will be stored to provide a continuous supply to the RO process. The equalization tank provides a constant source supply to the RO process in the event that the UF process is down. The RO permeate, once treated by the RO process, is then sent to the UV-AOP treatment process for final treatment, and to break down any remaining organic compounds. The RO system consists of two (2) skids, with two (2) stages per skid. Each skid has a permeate capacity of 70 gpm, for a total permeate capacity of 139 gm. The system is designed to perform between 80 and 85% recovery, and will use full scale 8-inch elements, with seven (7) elements per pressure vessel, with a total of three (3) pressure vessels per skid. The RO process and skid design criteria are provided in Tables 4 and 5. Table 4. RO Treatment Units Design Criteria Parameter Criteria Pretreated Feed Water Capacity (Total/per Skid) 174/87 gpm Permeate Recovery Rate 80 to 85% Permeate Capacity (Total/per Skid) 139/70 gpm Concentrate Capacity (Total/per Skid) 35/17.5 gpm Minimum/Maximum Raw Water Temperature 20/30 Degrees C Table 5. RO Treatment Skids Design Criteria Parameter Criteria Number of Skids Two (2) Number of Stages per Skid Two (2) Design Permeate Flux 12.0 gallons per square foot day (gfd) Number of Pressure Vessels per Skid (Stage 1/2) Three (3) (Two (2)/One (1)) Membrane Elements per Pressure Vessel Seven (7) Membrane Element Area 400 square feet 9

10 Filtered water from the UF system is first chemically pretreated with sulfuric acid (H2SO4) and scale inhibitor (antiscalant) to protect the RO membranes from fouling and scaling. The water is then split accordingly to pass through the two (2) skid mounted booster pumps, to provide enough pressure to pass through the cartridge filters, which help in the removal of any particulate matter that passed through the UF system or enter the break tank that may damage the RO membranes. The split flow is then passed through the two (2) skid mounted RO feed pumps, each of which provide enough pressure to transfer the pretreated water through its respective RO skid. The total combined permeate is sent to the UV-AOP process, and the RO concentrate is sent to the WRWRF headworks or RST, based on tested water quality. Fouling and scaling over time of the RO membrane elements will increase the required feed pressure and can have a significant effect on membrane performance and permeate production. A membrane CIP skid mounted system is typically used to facilitate the cleaning of the membrane elements in place and will incorporate a chemical mixing tank, recirculating pump, an immersion heater, a cartridge filter and instrumentation for monitoring cleaning activities. The RO skids will share the manual clean-in-place (CIP) skid system designed for cleaning one skid at a time. Ultraviolet and Advanced Oxidation Process (UV-AOP) The UV-AOP process is the final barrier in the treatment skid. The treatment objective compounds (NDMA and 1,4-dioxane) are well-recognized performance indicators for advanced oxidation. NDMA is highly susceptible to direct photolysis by UV light. When UV light directly photolyzes hydrogen peroxide (H2O2), two hydroxyl radicals (2 OH ) are formed for every hydrogen peroxide molecule. The compound 1,4-dioxane is highly susceptible to advanced oxidation by hydroxyl radicals. Most organic molecules are degradable by either direct photolysis, advanced oxidation, or a combination of both processes. The UV process consists of low pressure, high output lamps. The process stream flows through a single UV reactor consisting of a stainless steel vessel with a flanged inlet and outlet connection. The UV process design parameters are provide in Table 6. Table 6. UV-AOP Treatment Unit Design Criteria Parameter Criteria Number of Skids One (1) Maximum Flow per Skid 139 gpm Number of Chambers per Skid One (1) UV Dose 1 Minimum of 1,800 millijoules per square centimeter (mj/cm 2 ) Number of Bulbs per Chamber/Total 18 Energy Required per Bulb 0.26 kilowatts (kw) Nitrosodimethylamine (NDMA) Removal 1.2 log (94%) 1,4 Dioxane Removal 0.5 log (68%) 1 Sharpless, Charles M., and Karl G. Linden. Experimental and model comparisons of low-and medium-pressure Hg lamps for the direct and H2O2 assisted UV photodegradation of N-nitrosodimethylamine in simulated drinking water. Environmental Science & Technology 37.9 (2003):

11 Permeate from the RO process will flow to the UV process. The feed line for the UV skid will be equipped with a flow meter to allow for monitoring of constant flow to the reactor. The UV skid will consist of one (1) chamber. Temperature and UV intensity will be monitored at the end of the chamber. Purified water flow from the UV skid will be constant and stored in a 1,000 gallon purified water storage tank at the end of the process. The UV system takes up to four (4) minutes to warm up. Water flowing through the UV system prior to the bulbs being warmed up following start-up will be sent to the pump station. Chemical Storage Systems The major chemical process components of the plant will include pretreatment, in-line process chemicals, cleaning chemicals and post treatment chemicals. Generally, each process component will incorporate the use of different types of chemicals, however, there is some overlap in common chemicals, primarily those used for cleaning. Pretreatment to the purification process includes sodium hypochlorite and ammonium sulfate for converting any free chlorine in the water to chloramines (ammonia monochloramine - combined chlorine residual). Pretreatment to the RO process includes sulfuric acid and antiscalant, and hydrogen peroxide or sodium hypochlorite is added prior to the UV-AOP system. When combined with UV light, peroxide and hypochlorite are effective in breaking down complex organic compounds that have partially passed through the RO process. Shared cleaning chemicals include sodium hydroxide and citric acid. Hydrochloric acid will also be used in the UF cleaning regimen periodically to mitigate any iron fouling if present on the membrane modules. Sodium hypochlorite will also be used for UF CIP and CEB cleaning operations. Sodium bisulfite will be used to neutralize the solution waste prior to being discharged to the demonstration facility lift station. Based on the intended reuse for potable water supply, the basic design requirements for storage of chemicals were designed in accordance with the Florida Department of Environmental Protection (FDEP) regulations (Chapter , Florida Administrative Code (F.A.C.)) as well as the recommendations set forth in Recommended Standards for Water Works. A summary of the aqueous chemicals that will be used in the demonstration facility are summarized in Table 7. Table 7. Aqueous Chemical Properties Chemical Chemical Formula Active Solution Solution Density (lb/gal) Lb. of Active Chemical per gal. of Solution Ammonium Sulfate (NH4)2SO4 10% Sodium Hypochlorite NaOCl 12.5% Sulfuric Acid H2SO4 93% Scale Inhibitor N/A 100% Hydrogen Peroxide H2O2 35% Sodium Hydroxide NaOH 25% Citric Acid C6H8O7 30% Hydrochloric Acid HCl 20% Sodium Bisulfite NaHSO3 40%

12 The operators will maintain safe, controlled chemical environments by ensuring drums and totes are properly placed and stowed on chemical spill pads. Operators are to wear personal protective equipment (PPE) at all times when switching, handling or removing drums and totes. Chemical levels, if not monitored automatically by the treatment processes, will be logged daily by operating staff and will be reordered in advance as to maintain a 30 day supply. WATER MANAGEMENT Water management for the demonstration facility will consist of collecting and recycling wastewater flows from the WRWRF. Several process waste streams will be generated by the demonstration facility during normal operations and it may be necessary to divert process water to waste during process start up. These process waste flows will be collected in a lift station and pumped to the plant influent headworks of the WRWRF. Process waste streams will be generated during normal treatment process operation which includes the UF backwash wastewater (from the back-pulse system) and the UF feed strainer backwash wastewater (from the automatic strainer flush system). Return streams from the tank overflows may occur during ramping-up of the plant as part of the start-up sequence. Additionally, process water that does not meet water quality constraints may be wasted from the process and returned. RO permeate and concentrate flow streams will be sent to the lift station during start-up until the combined stream is proven to meet Florida public access reuse standards. Upon approval, the combined stream will be pumped separately to the existing RST at the WRWRF. A summary of anticipated process waste streams is included in Table 8. Table 8. Demonstration Facility Process Waste Streams Process Recycle Streams Duration Frequency RO Concentrate Continuous Continuous Sinks/Drains Continuous Intermittent RO Permeate Continuous Continuous UF Backwash Water Waste 2 minutes Every 40 minutes UF Feed Strainer Automated Backwash Waste 2 minutes Every 20 minutes UF CEB Water Waste 4 minutes Every 1,440 minutes UF CEB Water Waste 2 minutes Once per Week UF CIP Water Waste 2 minutes Once per Month UF CIP Tank Drain (250 gal. each) 5 minutes Start-up Feature RO CIP Tank Drain (250 gal. each) 5 minutes Start-up Feature Combined Water Tank Overflow (1,000 gal) 6 minutes Start-up Feature RO Feed Tank Drain (6,000 gal) 35 minutes Start-up Feature The process waste streams will be collected through floor drains within the building and conveyed via a gravity sewer line to the pump station. The combined waste streams will be pumped to the plant influent headworks of the WRWRF through a new PVC force main. Any waste flows containing process chemicals which need to be neutralized will be neutralized prior to discharge into the lift station. 12

13 SAMPLING PLAN Water quality parameters that will be sampled for during the two (2) year demonstration period will include general water quality parameters for physical, mineral and inorganic constituents for process monitoring and optimization. In addition to these parameters, sampling of primary and secondary drinking water standards will also be performed on a routine basis to confirm that the purified water meets the standards for full treatment and disinfection in Rule (3)(b), F.A.C and to demonstrate that the facility is able to achieve regulatory compliance. Sampling is also recommended to determine the concentrations of total organic halides (TOX) and total organic carbon (TOC) in the reclaimed and purified water relative to the requirements set forth in Rule (3)(d) and (e), F.A.C. Mutagenicity and pathogen sampling plans are also recommended in accordance with Rule (4)(c), F.A.C., for demonstration of removal of mutagenic substances, such as peroxide residuals, and inactivation of pathogens, including enteric viruses, helminth ova and cryptosporidium giardia. Sampling these constituents will verify the effectiveness of the advanced treatment system and provide confidence to the public that such constituents are being removed. Normal operation will consist of all demonstration facility processes in operation. The demonstration facility shall be in operation 24 hours a day except for routine maintenance, repairs and hazardous weather conditions; however, the sampling plan is scheduled for a typical 5-day work week. It is anticipated that demonstration testing of the conceptual treatment process will be performed to satisfy the requirements of Rule , F.A.C. and to provide the public with a high degree of confidence that the treatment processes can provide the required removal of contaminants in the reclaimed water. IMPLEMENATION The demonstration facility final design has been completed and construction of the facility is anticipated to begin in April Construction will take approximately one (1) year and the operation of the facility will begin in April 2018 for two (2) years, for completion in April

14 Figure 2. Demonstration Testing System Isometric View The City of Daytona Beach, as well as other cities and counties in the State of Florida will benefit from the Demonstration Testing Program results and recommendations. It will aid in providing development of the regulatory framework for potable reuse projects in the State of Florida, promoting and enhancing stakeholders overall acceptance and education of the technology and safety of producing drinking water from reclaimed water effluent, offsets future regional fresh groundwater withdrawals and supports minimum flow and level goals, reducing nutrient loading from the point source and addresses national numeric nutrient criteria (NNC), total maximum daily loads (TMDLs) as well as Basin Action Management Plan (BMAP) goals. 14