FINAL REPORT Alternative Water Supply Evaluation and Implementation Plan JEA

Transcription

1 FINAL REPORT 2011 Alternative Water Supply Evaluation and Implementation Plan JEA August 2011

2 Heading 1 (Section Number) Heading Table of Contents 1 (Section Title) Executive Summary Background Data Collection Prioritization of AWS Options Feasibility Evaluation for Implementation of Selected AWS Options mgd Options: Short Term/Small Scale Targeted Reuse: Source Replacement or Salinity Barrier Local Surface Water Reservoir for Potable Water Supply Intermediate Aquifer Supply Wells mgd Options: Medium Term/Scale Non Floridan Source Private Irrigation Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation mgd Options: Longer Term/Large Scale Desalination: Lower St. Johns River near NSGS (Seawater Quality) Desalination: Upper St. Johns River (Brackish Quality) Indirect Potable Reuse via Groundwater Recharge Shortlist of Recommended AWS Options Capital Cost for Shortlist of AWS Options Targeted Reuse: Source Replacement (5 mgd) Salinity Barrier (5 mgd in South Grid) Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation Desalination: Lower St. Johns River near NSGS (Seawater Quality) Estimated Capital and O&M Cost Comparisons for Recommended Options Implementation Plan for Selected AWS Options Targeted Reuse: Source Replacement [Small Scale/5 mgd Option] Targeted Reuse: Salinity Barrier (South Grid) [Small Scale/5 mgd Option] State of Florida Rules Related to Salinity Barrier Systems Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation [Medium Scale/15 mgd Option] State of Florida Rules Related to Keystone Region Floridan Aquifer Recharge i

3 5.4 Desalination: Lower St. Johns River near NSGS (Seawater Quality) [Large Scale/30 mgd Option] Appendix A AWS Options Screening Sensitivity Analysis Results Appendix B AWS Options Advantages/Disadvantages Summary Tables from JEA Workshop Appendix C Capital and O&M Cost Estimates for Recommended Alternative Water Supply Projects Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\TOC.docx ii

4 List of Figures 1 Location of Recommended JEA AWS Options Proposed Large Source Replacement for C&I User Proposed Salinity Barrier in South Grid Proposed Keystone Lake Region Floridan Aquifer Recharge Proposed Desalination WTP near St. Johns River (Seawater Quality) List of Tables 1 Initial Inventory of Potential AWS Options Grouping of Evaluation Criteria Variability of Lumped Criteria for Sensitivity Analysis Project Ranking Summary from Sensitivity Analysis (Baseline Scenario and Scenarios 1 4) Summary of Prioritized Options Capital and O&M Cost Comparison for Recommended Alternative Water Supply Projects Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\TOC.docx iii

5 JEA 2011 Alternative Water Supply Evaluation and Implementation Plan This report summarizes the engineering services performed by Camp Dresser & McKee Inc. (CDM) to provide JEA with a phased plan for implementing alternative water supply (AWS) projects scaled to meet forecasted supplemental potable water needs. A short term increment of 5 million gallons per day (mgd), a medium term increment of 15 mgd, and a longer term increment of 30 mgd were considered to satisfy service demands and anticipated regulatory requirements through the Year Executive Summary This report provides an updated evaluation and outlines an implementation plan for developing potential AWS projects over a variety of planning horizons and water supply capacities. This report is a continuation of JEA s on going efforts to ensure sustainable water supplies are developed in the future to meet growing demand. JEA s Total Water Management Plan, an on going program, and JEA s 2010 Alternative Water Supply Study provided the primary basis and foundation for the evaluations developed in this report. The initial list of AWS alternatives developed and screened included 18 different options. Alternative water supplies included desalination of high salinity surface water, reuse of treated wastewater effluent to replace potable water usage or to provide aquifer recharge, storage and treatment of fresh surface water, alternative aquifer systems to the Floridan Aquifer, and the use of stormwater for irrigation to replace potable water. The process followed for evaluation and screening included workshop based collaborative sessions with JEA and CDM. The focus of the workshops were to (1) ensure that a comprehensive list of options were being considered, (2) simplify the evaluation criteria by categorizing them based on Cost, Environmental/Regulatory and Technical Feasibility, (3) evaluate and conduct a sensitivity analysis of the initial list of options to short list a final set of options for evaluation, and (4) build consensus on the final options for recommendation and identify the necessary steps to consider for finalizing an implementation plan. Each alternative was categorized as to the magnitude of supply potentially available and general categories of 5 mgd, 15 mgd, and 30 mgd were established as part of the evaluation basis. 5 mgd Targeted Reuse This option considers identifying locations within the existing reclaimed water distribution system where targeted reuse might provide greater resource benefit than standard irrigation use. Two specific alternatives were considered under the targeted reuse option. 1

6 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan One is in identifying large Commercial and Industrial (C&I) users who could potentially replace current groundwater supplies with reclaimed water usage. The second is in providing for management of saline water intrusion potentially impacting existing potable supply wellfields. Both of these options for targeted reuse are consistent with the JEA CUP condition to increase the total use of effluent flow for beneficial reuse. Replacement of current C&I uses of the Upper Floridan Aquifer (UFA)with reclaimed water would provide a reduction in total UFA usage or possibly even the potential that the current C&I use could be re allocated for JEA potable supply. Although there are a number of C&I users with CUPs in the 5.0 mgd range, there are only a few who could use reclaimed water in place of potable water. Implementation of this option would involve further investigation into the C&I CUPs that have been identified, and the pursuit of an agreement between JEA and the C&I user. In addition, further evaluation into the treatment and transmission requirements is recommended. The second alternative identified under the targeted reuse option would be to create a salinity barrier between the Fernandina Permeable Zone and the Lower Floridan Aquifer at critical locations proximal to JEA wellfields impacted by saline water movement. This option would likely require further treatment of reclaimed water to drinking water standards and to inject the water into a series of wells designed to optimize continued use of existing supply wells. Implementation of this option will require additional groundwater modeling to determine the most feasible areas and injection rates and an evaluation to determine the required level of additional treatment dependent upon locations and depths of injection. 15 mgd Keystone Lake Region Floridan Aquifer Recharge This option would use treated effluent from the Southwest WWTP and possibly surface water from the Ortega or St. Johns Rivers to directly recharge the Florida Aquifer in an area approximately midway between the JEA service area and the Keystone Heights Lake Region. A recharge wellfield would provide for injection of the treated water directly into the Upper Floridan Aquifer to provide regional groundwater benefits. Implementation of this option would require a process treatment evaluation to determine the additional treatment that will be required at the Southwest WWTP. It is anticipated that filtration followed by nanofiltration or low pressure reverse osmosis, and then UV disinfection will be required. Additional groundwater modeling should be performed to identify optimal site location and recharge wellfield design. In addition, a pipeline routing analysis should also be performed to identify the most feasible route, which is approximately 15 miles long. 30 mgd Desalination: St. Johns River near NSGS "seawater quality" This option consists of water withdrawn from the St. Johns River and treated at a desalination facility colocated at the JEA Northside Generating Station (NGS) to produce finished water for potable supply to JEA customers. Implementation of this option would require a feedwater characterization and a process treatment evaluation as well as determination of requirements for the size of the facility site, the raw water intake and brine disposal systems, and possible transmission system modifications. Once complete, a pilot scale desalination facility would be recommended to further define treatment requirements and operating costs. 1.0 Background JEA s commitment to protecting and sustaining the environment has resulted in several ongoing initiatives including developing and actively promoting a rigorous water conservation program, expanding the use of reclaimed water, and moving forward with a program to study and potentially Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 2

7 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan implement AWS projects. The AWS planning that JEA has continued to pursue over the last several years has included preliminary evaluations of several AWS options as part of the 2008 and 2009 Total Water Management Plans and, most recently, with the completion of the 2010 AWS Study. The work presented in this report builds from and is a continuation of these efforts. Since there is uncertainty in the timing, quantity, and location of an AWS option(s) that JEA may develop, a variety of potential water supply/management options that build upon the work previously completed by JEA was prioritized using a phased approach for meeting an additional 5 mgd, 15 mgd, and 30 mgd demand above the CUP limit over the 20 year planning horizon (Years 2011 through 2030). It should be noted that most of the evaluations completed as part of this study were performed prior to the recent issuance of JEA s 20 year Consumptive Use Permit (CUP), which was approved on May 10, The recent JEA CUP renewal contains specific conditions that require JEA to further evaluate AWS options and continue to implement reuse to the maximum extent technologically, economically, and environmentally feasible. These specific conditions for additional reuse and further evaluation of AWS options fit well with the recommendations of this report, however, at the time this report was prepared, the timelines and recommended quantities were not known and therefore, this report does not address those with specificity. Tasks performed in support of this AWS Evaluation and Implementation Plan included the following: Data collection and analysis Prioritization of AWS options Feasibility Evaluation for implementation of selected AWS options Implementation Plan for selected AWS options As part of the background for this project, it should be recognized that several key on going legislative initiatives are being considered in the Florida Legislature that may swing a particular AWS option or options into or out of favor. These legislative initiatives were considered based on the most recent information. It will be important for JEA to continue to track these legislative initiatives and continue to support these on going efforts to ensure that they are adopted, to the extent possible, under favorable terms for JEA. These on going legislative initiatives include: Cooling Water Intake Structures CWA 316b o Public comment period closes August 18, 2011 o Proposed standards would keep Northside Generating Station (NGS) as a favorable site for a potential future desalination facility Numeric Nutrient Criteria o The June 13, 2011 letter from the U.S. EPA to FDEP allows FDEP to recommence its rulemaking efforts for both inland and estuarine waters CUP Credit for reducing potable water usage for reclaimed water customers who also have CUPs (i.e., Golf Courses) Reuse treatment criteria reducing the treatment requirements for indirect potable reuse associated with the recharging of the Upper Floridan aquifer Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 3

8 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan 2.0 Data Collection CDM reviewed the following reports and studies to evaluate previous AWS study efforts by JEA, to identify target areas and constraints for AWS projects, and to provide conceptual planning level cost estimates for the projects proposed: JEA Consumptive Use Permit and associated Technical Staff Report JEA 2010 Reuse Feasibility Summary Various SJRWMD, USGS, and FDEP reports and studies characterizing the water resources (flow and quality) and hydrogeology of the Lower St. Johns River basin SJRWMD Northeast Florida Regional Groundwater Flow Model JEA 2011 Annual Water Resource Master Plan JEA 2010 Alternative Water Supply Study DRAFT JEA Total Water Management Plans ( ) Cost estimating reports prepared in support of the SJRWMD and SFWMD Water Supply Plans, Georgia Environmental Protection Division Water Management Practice Cost Comparison (2011), and recent bid tabulations Preliminary Feasibility Investigation: Viability of the Intermediate Aquifer as a Water Source (2010) In addition, the most recent Geographical Information Systems (GIS) data on JEA s facilities, transmission systems, service areas, and parcel ownership were compiled for use in evaluating the implementation of the proposed alternatives. 3.0 Prioritization of AWS Options Fourteen AWS options were developed in the JEA 2010 AWS Study, and four new additional options/hybrids were identified by CDM for initial review. The inventory of options grouped by capacity (5 mgd, 15 mgd, and 30 mgd) is summarized in Table 1. To facilitate preliminary screening, the original 13 evaluation criteria presented in the JEA 2010 AWS study were simplified into 3 main categories (Cost feasibility, Environmental/Regulatory Feasibility, and Technical Feasibility) as shown in Table 2. In order to focus on the most beneficial options for further evaluation, a validation/sensitivity analysis was performed to determine the variability of the assigned criteria and weighting factors used for computing relative benefit scores. Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 4

9 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan Table 1. Initial Inventory of Potential AWS Options No. 1 AWS Option Desalination: Lower St. Johns River near NSGS (seawater quality) Supply Capacity (mgd) No. 2 Desalination: Upper St. Johns River (brackish quality) 30 No. 3 Desalination: Intracoastal Waterway/ Atlantic Ocean 30 No. 4 Desalination: Brackish Groundwater 30 No. 5 Indirect Potable Reuse via Groundwater Recharge 30 No. 6 Keystone Lake Region Floridan Aquifer Recharge (RIBs, Injection, or Direct Lake Recharge) 30 No. 7 Direct Potable Reuse 30 No. 8 Non Floridan Source Private Irrigation 15 No. 9 Intermediate Aquifer Wells Co located at Existing Water Treatment Plants 15 No. 10 Multi County Regional Reuse 15 No. 11 *Keystone Lake Region Floridan Aquifer Recharge Southwest WWTP + Surface Water Augmentation 15 No. 12 Regional Surface Water Reservoir for Potable Water Supply 15 No. 13 Regional Surface Water Reservoir for Irrigation Water Supply 15 No. 14 Distributed Stormwater Collection for Potable Use 5 No. 15 Distributed Stormwater Collection for Supplemental Reclaimed or Direct Irrigation 5 No. 16 *Targeted Reuse: Source Replacement or Salinity Barrier 5 No. 17 *Local Surface Water Reservoir for Potable Water Supply 5 No. 18 *Desalination: St. Johns River near NSGS (seawater quality) 5 *Additional AWS Options developed by CDM not included in the JEA 2010 AWS Study 30 Table 2. Grouping of Evaluation Criteria Evaluation Criteria Location of Project Relative to JEA Service Area Operational Complexity Relative Capital Treatment Costs Relative Capital Transmission Costs Relative O&M Costs Revenue Impact Environmental Issues/Difficulty of Permitting Secondary Environmental Impacts Regional Impacts to WMD Constraints Relative Potential Capacity (mgd) Technological Risks/Unknowns/Public Perception Years to Implement Scalability Lumped Criteria Cost Cost Cost Cost Cost Cost Environmental/Regulatory Environmental/Regulatory Environmental/Regulatory Technical Feasibility Technical Feasibility Technical Feasibility Technical Feasibility Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 5

10 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan Each of the criterion that were originally developed as part of the JEA 2010 AWS study was grouped into one of three simplified categories as shown in Table 2, which resulted in the following baseline weight distribution: Cost Feasibility (40 percent); Technical Feasibility (30 percent), and Environmental/Regulatory Feasibility (30 percent). To determine the effect of weighting on project ranking, a sensitivity analysis was completed by evaluating four alternative weightings, as summarized in Table 3. Scenario No. Cost Table 3. Variability of Lumped Criteria for Sensitivity Analysis Technical Feasibility Environmental/ Regulatory Feasibility Scenario Description Baseline 40% 30% 30% Balanced Portfolio 1 50% 25% 25% Increased weight on cost 2 75% 15% 10% Highest weight on cost 3 15% 10% 75% Highest weight on Environmental/ Regulatory Constraints 4 30% 60% 10% Highest weight on Technical Feasibility Graphical representations of the sensitivity analyses are provided in Appendix A. A summary of the ranking results for all five scenarios evaluated in the sensitivity analysis is shown in Table 4. Table 4. Project Ranking Summary from Sensitivity Analysis (Baseline Scenario and Scenarios 1 4) Baseline Scenario 1 Scenario 2 Scenario 3 Scenario 4 Weight Weight Weight Weight Weight Cost 40% 50% 75% 15% 30% Technical Feasibility 30% 25% 15% 10% 60% Environmental/Regulatory 30% 25% 10% 75% 10% Option # Capacity (mgd) AWS Option No. 9 5 Intermediate Aquifer Wells Colocated at Existing WTPs No Non Floridan Source Private Irrigation No Targeted Reuse: Source Replacement or Salinity Barrier No Regional Surface Water Reservoir for Irrigation Water Supply No Keystone Lake Region Floridan Aquifer Recharge SW WWTP Surface Water Augmentation No Indirect Potable Reuse via Groundwater Recharge No Keystone Lake Region Floridan Aquifer Recharge (RIBs, Injection, or Direct Lake Recharge) Rank Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 6

11 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan Option # Capacity (mgd) No AWS Option Regional Surface Water Reservoir for Potable Water Supply Rank No Multi County Regional Reuse No Local Surface Water Reservoir for Potable Water Supply No Desalination: Brackish Groundwater No No No No No Distributed Stormwater Collection for Supplemental Reclaimed or Direct Irrigation Desalination: Intracoastal Waterway/Atlantic Ocean Desalination: St. Johns River near NSGS (seawater quality) Distributed Stormwater Collection for Potable Use Desalination: Upper St. Johns River (brackish quality) No Direct Potable Reuse No Desalination: St Johns River near NSGS (seawater quality) Note: Options above highlighted in blue rank in the top 5 for each scenario CDM reviewed this sensitivity analysis with JEA in a workshop meeting on February 10, 2011 and based on the results of the ranking evaluation and feedback from JEA during the meeting, eight options were proposed for further analysis and are summarized in Table 5. Table 5. Summary of Prioritized Options AWS Option Supply Capacity (mgd) No. 16 Targeted Reuse: Source Replacement or Salinity Barrier 5 No. 17 Local Surface Water Reservoir for Potable Water Supply 5 No.9 Intermediate Aquifer Supply Wells 5 No. 11 Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation 15 No. 8 Non Floridan Source Private Irrigation 15 No. 1 Desalination: Lower St. Johns River near NSGS (seawater quality) 30 No. 2 Desalination: Upper St. Johns River (brackish quality) 30 No. 5 Indirect Potable Reuse via Groundwater Recharge 30 Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 7

12 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan A brief summary of each prioritized option by capacity is listed below: 5 mgd Options: No. 16 Targeted Reuse: Source Replacement or Salinity Barrier This option may consist of using available reuse for the following applications: (1) replacing an existing major commercial/industrial (C&I) use of a potable source; or (2) groundwater salinity management. Intermediate Aquifer Supply (IAS) Wells This option consists of construction of wells or a wellfield targeting the IAS as the source of supply for potable or irrigation use. No. 17 Local Surface Water Reservoir for Potable Water Supply This option consists of construction of an off line storage reservoir on a tributary to the St. Johns River to store wet weather flow to be treated and used as potable supply. 15 mgd Options: No. 8 Non Floridan Source Private Irrigation This option consists of construction of groundwater wells either in the surficial aquifer or the intermediate aquifer to supply irrigation water to private residences. This use would replace the Upper Floridan aquifer (UFA) supply currently being used to meet those demands. No. 11 Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation This option consists of using reclaimed water from the Southwest WWTP and a supplemental flow from a surface water source (possibly the Ortega River or the St. Johns River) and treating it to water quality standards required for groundwater recharge via rapid rate land application systems in the Keystone Heights Lake Region. The water quality would have to meet primary drinking water standards, however, exemptions are allowed based on the water quality of the receiving groundwater. During evaluation of this option, another concept was developed to inject treated effluent at an intermediate location between Keystone Heights and Jacksonville to achieve the same goal at a lower cost. Under this scenario, direct injection into the Florida Aquifer would require additional treatment to meet both primary and secondary drinking water standards. However, the additional treatment costs would still be significantly less than the increased distribution costs required to move the water all the way to Keystone Heights. 30 mgd Options: No. 2 Desalination: Upper St. Johns River (brackish quality) This option consists of water withdrawn from the St. Johns River and treated at an upstream location, possibly near the Shands Bridge (SR16) between Clay County and St. Johns County, where the water is a relatively consistent brackish quality (TDS less than 8,700 mg/l), and the finished water would be used for potable supply. No. 1 Desalination: Lower St. Johns River near NSGS (seawater quality) This option consists of water withdrawn from the St. Johns River and treated at a desalination facility co located at the JEA NSGS with variable water quality and salinity often near seawater salinity quality (TDS ranging from 28,000 mg/l to 35,000 mg/l) and the finished water would be used for potable supply. No. 5 Indirect Potable Reuse via Groundwater Recharge This option consists of reclaimed water treated to potable water quality standards including disinfection standards prior to injection into the Floridan aquifer for purposes of groundwater recharge. This option would require that the SJRWMD Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 8

13 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan provide a potable water credit for the amount of water injected, which would most likely require a negotiated agreement. 4.0 Feasibility Evaluation for Implementation of Selected AWS Options As noted in Section 3.0, the list of possible AWS options was evaluated and reduced to eight different options that were grouped into three capacity categories: 5 mgd, 15 mgd, and 30 mgd. Each of these eight options was further assessed for their technical, environmental, and regulatory feasibility. The objective of this feasibility screening was to further reduce the final list of options to a subset of three alternatives that appear most feasible for implementation by JEA. The advantages and disadvantage of the eight shortlisted AWS options were discussed and finalized during workshops with JEA. A summary of each option is outlined below and the detailed advantages/disadvantage tables are included in Appendix B mgd Options (Short Term/Small Scale) The three options advanced for further consideration that could most likely satisfy the 5 mgd capacity category are as follows: No. 16 Targeted Reuse: Source Replacement or Salinity Barrier No. 17 Local Surface Water Reservoir for Potable Water Supply No. 9 Intermediate Aquifer Supply Wells Targeted Reuse: Source Replacement or Salinity Barrier Targeted (strategic) reuse is the use of reclaimed water to either replace current competing groundwater withdrawals or to protect the current groundwater supply from degradation of water quality. Two alternatives were considered for this option. The first alternative would be the replacement of permitted groundwater withdrawals with reclaimed water for large C&I entities. The second would provide control of groundwater salinity in areas where saline water intrusion has been indicated and potentially threatens JEA supply sources. With regard to source replacement, SJRWMD records show that there are four large n0n JEA C&I permitted groundwater users within Duval County that utilize the Upper Floridan aquifer as their primary source of supply: Stone Container Corporation (a paper mill with a pumping rate of 8.8 mgd) Anheuser Busch (a brewery with a pumping rate of 4.2 mgd) MC (an unknown entity with a pumping rate of 1.8 mgd) IFF Chemical Holdings (Formerly Bush, Boake and Allen is a chemical processing plant that manufactures flavor and fragrance chemicals and aroma chemicals for the food, beverage, pharmaceutical, and household products with a pumping rate of 1.7 mgd) Anheuser Busch and IFF Holdings were both eliminated from further consideration for obvious public acceptability concerns since the water would have to be treated to support direct potable reuse for products/beverages. Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 9

14 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan For the targeted reuse alternative to be feasible, the potential customers would need to be relatively close to an existing JEA reclaimed water main. Of the two remaining large C& I groundwater users, only Stone Container is relatively close to an existing JEA reclaimed water main (within 1 mile of an existing 24 inch diameter reclaimed water main). This user is currently in receivership, although they continue to use potable water for their industrial processes as of 2010 based on a review of SJRWMD EN 50 pumping data. In addition to the above non JEA groundwater users, there may also be future opportunities to expand the use of reclaimed water to replace groundwater withdrawals at JEA power generation facilities. Currently, the NSGS and SJRPP use approximately mgd of reclaimed water from District II but it is uncertain at this time if the use of reclaimed can be expanded in the future at these power generation facilities. The second alternative under this option would be to use injected reclaimed water as a salinity barrier to saltwater intrusion within the aquifer system. The primary mechanism for saltwater intrusion into the Floridan aquifer system within Duval County and the surrounding area is the upconing of trapped relic seawater from the Fernandina Permeable Zone (vertical intrusion) at the base of the Lower Floridan aquifer. A salinity barrier would consist of the injection of freshwater into the Lower Floridan aquifer to help reduce the upward vertical gradient from the Fernandina Permeable Zone to the water production zones of the Upper Floridan aquifer. This concept was evaluated by the U.S. Geological Survey (Sepulveda and Spechler, 2003) in cooperation with the SJRWMD and JEA. The USGS developed a four layer groundwater flow model including both the surficial and Floridan aquifer systems to assess the effects of freshwater injection wells in mitigating groundwater quality degradation for two South Grid JEA wellfields (Deerwood and Brierwood). Model simulations were developed to evaluate a total of 18 mgd of water withdrawn fr0m the Main Street wellfield (north of the St. Johns River) and injected into the Lower Floridan aquifer at Deerwood (12 mgd) and Brierwood (6 mgd) wellfields. As a result of this action, the model showed that the upward flow of poorer quality groundwater from the Fernandina Permeable Zone (a non production zone beneath the Lower Floridan aquifer) was decreased, but the upward vertical gradient (upconing) was not completely eliminated. Additionally this option, from both an aquifer recharge perspective and a salinity barrier secondary benefit, was further evaluated by JEA as documented in the JEA 2008 TWMP. As it currently stands, the TWMP recommended alternative to address water quality trending in the south grid is to move forward with the north to south grid transfer. The north to south grid transfer is an important component for ensuring that JEA can continue to meet water supply demands and utilize the aquifer in a sustainable manner. Moving forward with a small scale salinity barrier may compliment the on going efforts to implement the north to south grid transfer in two important ways: (1) having a salinity barrier in place may provide some additional timing benefits in the interim as the large transfer project is brought on line, and (2) over time having both components available may provide additional flexibility in maximizing safe yield of the south grid while also optimizing how much water is required for transfer from north to south thus providing a potentially significant operational cost savings. The intent of this small scale alternative would be to improve the water quality in the vicinity of the South Grid wellfields by injecting highly treated reclaimed water into the Lower Floridan aquifer. Groundwater modeling will be necessary in support of this evaluation to determine tradeoffs between simulated injection ratios and increased production rates. A design injection to withdrawal ratio will need to be negotiated with the SJRWMD during the preliminary planning stage prior to committing to a significant capital investment. The concept proposed for this study would be to treat reclaimed water from the Arlington East WRF to Groundwater Recharge quality defined in Part V of Chapter , FAC and inject the water into the Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 10

15 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan Lower Floridan aquifer near wellfields in the JEA South Grid (Ridenour, Oakridge, and Deerwood wellfields) using a series of injection wells. As of December 2010, wastewater flows at the Arlington East WRF averaged approximately 14 mgd. This concept requires treatment to primary and secondary drinking water standards and high level disinfection requirements. Exemptions to the primary and secondary drinking water standards may be approved based on the water quality of the receiving aquifer. Analysis of the current quality of the treated effluent would be required to identify what type of additional treatment technologies would be required. Public perception can be a difficult obstacle to overcome for this concept, although similar projects have been implemented in Florida. For example, the West Palm Beach Wetlands Based Indirect Potable Reuse Project is an operating project that recharges the surficial aquifer wellfield, which is a surface (drinking) water supply source for the City of West Palm Beach. Considering all of the factors identified herein, both of the targeted reuse/source water replacement projects identified in this section are recommended for the shortlist of AWS options. Groundwater modeling would be required to confirm actual offsets for the salinity barrier option along with subsequent hydrogeologic and geotechnical investigations to support the design of this alternative. An injection to withdrawal ratio of 1.5 will be used to further evaluate this alternative, although this ratio will ultimately require negotiations with the SJRWMD prior to implementation. This option is consistent with JEA s CUP condition to increase the total use of effluent flow for beneficial reuse Local Surface Water Reservoir for Potable Water Supply Under the federal Safe Drinking Water Act amendments, reservoirs can only be used for raw water storage associated with water treatment facilities. A surface water reservoir located in Duval County near the St. Johns River could be used to store water from the St. Johns River or a tributary to the St. Johns River (e.g., Ortega River) when water is plentiful and the water quality is more compatible with drinking water or reuse augmentation goals. A reservoir would provide flow equalization, which is needed to balance supply availability with demand. Surface water reservoirs have been used throughout central and south Florida. They are typically land intensive and have a history of seepage problems through earthen embankments. From a public perception standpoint, there is a Not in My Back Yard (NIMBY) attitude since they can be very unsightly in the landscape due to the height of the levees and the potential for flooding if the levees fail for any reason. Finally, there are many regulatory hurdles in the design and permitting of these facilities. For these reasons, other small scale options may be more technically and environmentally feasible Intermediate Aquifer Supply Wells The Intermediate Aquifer System (IAS) has been used as a water supply source by utilities in southwest Florida for many years. The IAS consists of permeable lenses of limestone, shell, and sand that occur within the Hawthorn Group. It is not widely recognized as a water supply source used by utilities in northeast Florida. In a few locations in northeast Florida, this aquifer has been used for private domestic supply wells. In certain locations, the intermediate aquifer can yield fairly substantial quantities of water in the range of 200 to 300 gallons per minute (gpm). One of the disadvantages of this option is that this aquifer is not regionally extensive; therefore, the water source is not present at every location in the service area. Also, where present, the IAS can be hydraulically connected (little to no confining layer separating the IAS from overlying or underlying aquifers) to the surficial aquifer and/or the Upper Floridan aquifer. Therefore, when this occurs, pumping of these wells may add to the cumulative groundwater drawdown associated with these aquifers further impacting the environmental constraints limiting withdrawals from the surficial aquifer and/or Upper Floridan aquifer. Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 11

16 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan In order to confirm some of these assertions, CDM contacted two local well drillers in northeast Florida: Partridge Well Drilling and Floyd & Sons, Inc. Both well drillers indicated that IAS wells, where present, have historically produced relatively small quantities of water, and both drillers discouraged the use of this source for potable water supply. Although the uncertainty and relative unknowns associated with this option limit it from consideration in this report, this option does warrant further conceptual investigation which would include a limited geotechnical evaluation, hydrogeologic testing and analysis of the obtained data. This is further supported by the recommendations outlined in the study commissioned by JEA in 2010, Preliminary Feasibility Investigation: Viability of the Intermediate Aquifer as a Water Source (2010). Considering that a limited data acquisition program could be implemented for a relatively inexpensive cost, our team recommends the following test program: Identify potential locations for a supplemental IAS test well at existing JEA water plants based on previous studies and a screening of known lithologic data. Drill a supplemental IAS test well at each of the JEA WTP s identified in the initial pre screening above to determine lithologic, geophysical and water quality parameters. Conduct short term pumping tests on each test well that shows promise to determine water quality, drawdown information and potential production rates. The water produced during the test program would be used for potable water once the quality is confirmed to meet primary and secondary drinking water standards. Once the test program is complete, the test well could be left as a monitoring well or, if suitable production rates are confirmed, the well could be placed into service upon permitting with the SJRWMD and FDEP. If the IAS is shown to be a feasible resource, then the key advantage to this test program approach, in addition to it being relative inexpensive, is that minimal additional infrastructure is needed to bring this resource into the JEA treatment and supply system mgd Options Medium Term/Scale Two options were advanced that could be used to satisfy the 15 mgd capacity category, as follows: No. 8 Non Floridan Source Private Irrigation No. 11 No. 11 Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation Non Floridan Source Private Irrigation This option consists of replacing irrigation demands from existing private Floridan aquifer wells with either intermediate aquifer or surficial aquifer wells. JEA would provide incentives for homeowners or businesses to move away from using Floridan irrigation wells, or install surficial irrigation wells. According to the SJRWMD, there are currently 665 domestic self supply wells in Duval County (estimated withdrawal is 3.3 mgd) with an estimated increase of 755 private domestic self supply wells in 2030 (estimated withdrawal is 8.9 mgd). These wells withdraw from the Upper Floridan Aquifer and provide potable water (indoor use) in addition to water for irrigation. In the case of domestic self supply wells, it is assumed that use of the Upper Floridan supply wells would likely be maintained for potable in house use, and a second well withdrawing from the surficial or intermediate aquifer would be installed for irrigation water supply. Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 12

17 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan In support of past District Water Supply Assessments, the SJRWMD typically assumes that percent of total residential demand is attributed to landscape irrigation. Assuming that 50 percent of the water from a private domestic Upper Floridan supply well is used for irrigation purposes, then this should translate into an irrigation water use of 4.5 mgd in Estimated costs for irrigation well replacement is $5000 to $7000 per well including well, pump, and electrical service. If this concept can be shown to garner a high degree of participation so that a large quantity of UFA water use is replaced, then the cost per gallon would be very attractive. However, most of the owners of these wells are not likely to be JEA customers, and there may be some difficulty in getting wide spread participation if well owners are not convinced of the value in changing sources or adding a second well. As an alternative to obtain a higher volume benefit (in the range of 15 mgd), around 37,000 households (averaging an irrigation demand of 12,500 gallons/month/household) within the JEA service area would need to convert to a private irrigation well. However, beyond the cost of a rebate or other funding mechanism for installation, this option represents a direct loss of revenue to JEA from a reduction in water supplied. Given all of these factors, this option is not recommended for further evaluation Keystone Lake Region Floridan Aquifer Recharge SW WWTP + Surface Water Augmentation This option consists of using reclaimed water from the Southwest WWTP to directly recharge the Floridan aquifer through direct injection. It is likely that there may not be sufficient reclaimed water available for recharge exclusively from the Southwest WWTP since average wastewater flows at this facility (as of December 2010) were approximately 8.8 mgd. Therefore, it may be possible to augment the reclaimed water supply with surface water from the Ortega River, which is located in close proximity to this facility. Based on the results of the 2010 AWS Study, this fresh water source may be able to supply as much as 6.7 mgd (maximum reliable yield). The original Keystone Heights Lake Region recharge concept was developed to provide the entire 30 mgd of AWS; however, much of the proposed reclaimed water supply would be produced at the Buckman WRF. Constructing a pipeline from Buckman through urban Jacksonville with ultimate discharge to the Keystone Heights area is not considered economically feasible. Therefore, the option was revised to meet the flow requirements of the intermediate capacity option. Ideally, the water would be delivered via rapid infiltration basins (RIBs) or direct lake recharge to the sandhill lakes area of Keystone Heights, which is a moderate to high recharge area for the Floridan aquifer. The primary limitation of recharging the aquifer directly in Keystone Heights is the cost of the pipeline to convey water all the way to Keystone Heights (approximately 30 miles), which was factored into the larger capacity option (30 mgd Option # 6). Given the distance, attendant cost and the anticipated lower capacity of this option, alternative consideration was given to providing a similar aquifer recharge benefit at a location closer to existing JEA facilities. However providing beneficial aquifer recharge outside of the Keystone Lakes Region would likely require direct injection into the UFA as confining beds in the area would limit the benefit for a RIB type application. For this lower capacity, direct injection option sites were considered along the border of the Duval/Clay county line and in Clay County, in the vicinity of the City of Middleburg as an economical approach to achieve the goal of aquifer recharge. A series of Upper Floridan aquifer injection wells would be needed to deliver the highly treated reclaimed water into the aquifer. Based on a review of the reclaimed water quality of Arlington East WRF, Mandarin WRF and District II WRF, water quality issues will be a challenge for either option since the maximum contaminant level (MCL) is exceeded for many of the primary and secondary drinking water standards. Treatment requirements will be greater for the direct injection option since the effluent will be directly injected into Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 13

18 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan an aquifer that is used for potable water supply (the UFA in this area is a class G I groundwater); however transmission system requirements and pumping costs will be less. As an example, the 30 mgd option evaluated in the JEA 2010 AWS study estimated that the total pumping and transmission costs would be around $282M, whereas for this option (15 mgd) the pumping and transmission costs would be approximately $70M. Both options require that primary and secondary drinking water standards are met; however, less treatment should be required for the Keystone Heights RIB option since these RIBs will discharge into the surficial aquifer (Class G II groundwater), and a zone of discharge is allowed. Treatment process upgrades at the Southwest WWTP would depend on which method and location is chosen for aquifer recharge. For purposes of this evaluation, the direct injection option is recommended for initial cost estimating purposes due to the length and cost of the transmission system to the Keystone Heights area. Anticipated process upgrades to the Southwest WWTP will be required and modification of the process to incorporate surface water flows from the Ortega River would be required. Currently, the Southwest WWTP only provides basic UV disinfection with no filtration. The treatment process will require modification, and the modifications will consist of filtration followed by either nanofiltration or low pressure reverse osmosis depending on the contaminants that must be removed. This process will then be followed by UV disinfection. It is anticipated that the nanofiltration or low pressure reverse osmosis process would not be required if RIBs were implemented. Public perception of injecting reclaimed water into an aquifer that supplies drinking water will most likely be negatively viewed, and this will be a major disadvantage to this option. However, JEA may be able to negotiate a one to one offset for withdrawal to injection ratio with the SJRWMD since this alternative directly augments the drinking water supply. Groundwater modeling would need to be completed to confirm actual offsets along with subsequent hydrogeologic and geotechnical investigations to support design of this alternative. Confirmation of the beneficial extent to augmenting water supply in the proposed area would need to be negotiated with the SJRWMD. Given many of the positive benefits of implementing this option, it is recommended for the shortlist of AWS options. A life cycle cost comparison of the direct injection option at a location much closer to Southwest WWTP (higher treatment requirements and O&M costs) to the Keystone Heights RIBs option (lower treatment requirements and O&M costs) is warranted mgd Options Longer Term/Large Scale Three options were advanced that could be used to satisfy the 30 mgd capacity category, as follows: No. 1 Desalination: Lower St. Johns River near NSGS (Seawater Quality) No. 2 Desalination: Upper St. Johns River (Brackish Quality) No. 5 Indirect Potable Reuse via Groundwater Recharge Desalination: Lower St. Johns River near NSGS (Seawater Quality) This option consists of pumping and treating water from the St. Johns River near the NSGS, where the water quality is very similar to seawater. Co locating this facility near a power generating facility has several advantages. There is an unlimited supply of seawater for treatment and potable use. The higher temperature water that was previously used for cooling in power generation can offset some of the higher operating costs associated with the high pressure RO that would be required to treat the water. There should be less negative public perception for this option and the regulatory requirement should be minimal since the existing power plant has a permitted discharge at a significantly higher rate than the Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 14

19 Final Report JEA 2011 Alternative Water Supply Evaluation and Implementation Plan amount of concentrate, thus providing sufficient dilution to stay within current discharge requirements. However, EPA has proposed new standards under Section 316(b) of the Clean Water Act for all existing power generation facilities, which may require reductions in intake flow to levels that could jeopardize the feasibility of this option. Considering the technical and environmental factors currently in place, and what appears to be favorable regulatory rule making (as of now), this option is recommended for the shortlist of AWS options Desalination: Upper St. Johns River (Brackish Quality) This option consists of constructing a low pressure reverse osmosis facility along the St. Johns River to treat the water to potable quality. This type of facility could be sited near the Shands Bridge at SR 16 in St. Johns County within the JEA water service area and relatively close to future high demand service areas. There is potentially a relatively large volume of water available for supply since there are no downstream users and no established MFLs for the river in this area; however, there may still be a negative perception from environmental groups for water withdrawal. Until future high demand service areas are built out, the finished water from this facility would be distributed to the South Grid for mitigation of groundwater drawdown impacts. The biggest technical and regulatory disadvantage for this alternative is concentrate disposal from the low pressure RO process. Given that this facility is relatively far inland (20 miles) complicates concentrate disposal. Since there is little local surface water mixing zone capability, the disposal location that would be the easiest option to permit would be the Atlantic Ocean. In south Florida, much of the concentrate is disposed of through deep injection wells into the Oldsmar Formation, which is part of the Lower Floridan production zone in Duval County. There may be deeper injection zones in the Cedar Keys formation or below that have not have been thoroughly vetted in this area. This would require review of drilling logs from exploratory oil wells in this region. Given all of these factors, this option is not recommended for further consideration Indirect Potable Reuse via Groundwater Recharge This option consists of treating wastewater effluent from one or more, large wastewater treatment facilities to meet the requirements for indirect potable reuse or groundwater recharge pursuant to Part V of Chapter , FAC. The reclaimed water produced from this type of facility would be used to directly recharge the drinking water source such as the Floridan aquifer. This option is similar in concept to the salinity barrier alternative discussed under targeted reuse/source replacement (see section 4.1 above) and Keystone Heights Lake Region Recharge/Direct Injection Option (see section above), but less specific in application and larger in magnitude than those options. It could also be used to augment a surface water project such as described in section Therefore, this alternative by itself is not recommended for further evaluation to the shortlist of AWS options, although it can be considered a broader category concept to the other AWS options still being considered under the 5 and 15 mgd capacity alternatives. 4.4 Shortlist of Recommended AWS Options Based on CDM s scope for this work, three options were to be recommended for further evaluation. Based on the evaluation of the technical, environmental, public/community perception and regulatory feasibility of the eight options, the three shortlisted recommended options for this study are the following: No. 16 Targeted Reuse: Source Replacement or Salinity Barrier (5 mgd) Z:\6103_JEA\80986 CUP AWS_Implementation\Report\Final\JEA_AWS_Final_Report.docx 15