Contents. Executive Summary. Section 1 - Introduction. Section 2 - Objectives. Section 3 Surficial Aquifer. Section 4 Seawater Desalination

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2 Contents Executive Summary ES.1 ES.2 ES.3 ES.4 ES.5 ES.6 ES.7 Section 1 - Introduction Section 2 - Objectives Background... ES-1 Pros and Cons... ES-1 Schedule for Implementation of Alternative Water Supplies... ES-3 Costs of Alternative Water Supplies... ES-3 Ranking of Alternative Water Sources... ES-4 Potential for Interim Water Supply from the UFA... ES-6 Alternative Water Supply Master Plan Recommendations... ES-7 Section 3 Surficial Aquifer 3.1 Permitting of Withdrawals from the Surficial Aquifer Pros and Cons of the Surficial Aquifer Cost Impacts Opinions of Capital Cost Opinions of Operation and Maintenance Cost Opinions of Total Production Costs Schedule of Implementation Section 4 Seawater Desalination 4.1 Permitting of Seawater Desalination Pros and Cons of Seawater Desalination Cost Impacts Schedule of Implementation Section 5 Fresh Surface Water/Reservoirs 5.1 Permitting of Fresh Surface Water Withdrawals from Water Management Areas or Reservoirs Pros and Cons of Using Fresh Surface Water Cost Impacts Schedule of Implementation Section 6 Conclusions and Recommendations 6.1 Conclusions Recommendations References N:6706/WLB3010 TOC.doc i

3 Table of Contents Draft Alternative Water Supply Master Plan Appendices Appendix A Letter from Kirby Green of SJRWMD to the Honorable Gary Wheeler Appendix B Summary and Methodology, C-25 Basin and Upper St. Johns River Basin Reconnection, St. Lucie and Indian River Counties, January 26, 2006, Final Report Prepared for SJRWMD and SFWMD N:6706/WLB3010 TOC.doc ii

4 Tables Table of Contents Draft Alternative Water Supply Master Plan ES-1 ES-2 ES-3 Pros and Cons Associated with Alternative Water Supplies... ES-2 Schedule for Implementation of Alternative Water Supplies... ES-3 Summary of Opinion of Probable Cost for Treatment Technologies Using Various Raw Water Sources... ES St. Johns River Water Management District Planning Estimates and Projections Opinion of Probable Capital Cost Treatment Technology: Nanofiltration Opinion of Annual Operation and Maintenance Cost Treatment Technology: Nanofiltration Opinion of Total Production Cost Treatment Technology: Nanofiltration Summary of Capital Cost Treatment Technology: Tampa Bay Water Seawater RO Summary of Annual Operation and Maintenance Cost Treatment Technology: Tampa Bay Water Seawater RO Summary of Total Production Cost Treatment Technology: Tampa Bay Water Seawater RO Opinion of Probable Capital Cost Treatment Technology: Seawater RO Opinion of Annual Operation and Maintenance Cost Treatment Technology: Seawater RO Opinion of Total Production Cost Treatment Technology: Seawater RO Summary of Capital Cost Treatment Technology: Tampa Bay Water Surface Water Treatment Plant Summary of Annual Operation and Maintenance Cost Treatment Technology: Tampa Bay Water Surface Water Treatment Plant Summary of Total Production Cost Treatment Technology: Tampa Bay Water Surface Water Treatment Plant Opinion of Probable Capital Cost Treatment Technology: Microfiltration/Ultrafiltration N:6706/WLB3010 TOC.doc iii

5 Table of Contents Draft Alternative Water Supply Master Plan Figures 5-5 Opinion of Annual Operation and Maintenance Cost Treatment Technology: Microfiltration/Ultrafiltration Opinion of Total Production Cost Treatment Technology: Microfiltration/Ultrafiltration Proposed Pipeline Cost from Various Surface Water Storage Areas to Indian River County North Water Treatment Plant Summary of Opinion of Probable Cost for Treatment Technologies Using Various Raw Water Sources Projected Population for the Indian River County Water Service Area Projected Finished Water Demands Projected Water Raw Water Withdrawals Indian River County Surface Water Basins Indian River and St. Lucie County Water Control Districts Indian River County Proposed Pipeline Routes N:6706/WLB3010 TOC.doc iv

6 Executive Summary ES.1 Background Indian River County Board of County Commissioners (BOCC) has requested an evaluation of alternative water supply sources to meet the County water supply needs through 2025 and beyond. The County has been experiencing rapid growth with concomitant increases in demands for water. The County currently uses the Upper Floridan Aquifer (UFA), brackish water, as the source for the production of public water supply through the reverse osmosis treatment process. This source is also used by agricultural interests for citrus cultivation and by local golf courses for supplemental irrigation (primary source for irrigation in most cases is reclaimed wastewater). In the process of expanding the County s North County Water Treatment Plant and wellfield, concerns were expressed that continued development of the UFA would have adverse impacts on the existing use of artesian wells for both irrigation and freeze protection. The County has an immediate need to expand the North County Water Treatment Plant to meet pending contractual demands. At the end of 2006, the County was in danger of exceeding the allocated annual withdrawal permitted in the existing Consumptive Use Permit (CUP). Therefore, the County had to obtain a Temporary Consumptive Use Permit (TCUP) to increase the annual withdrawal to meet demand and avoid an exceedance of the permitted volume. The County has an additional TCUP pending to allow for construction of an additional three wells associated with the expansion, as well as the corresponding allocation increase from 9.85 mgd to mgd. The County anticipates that by 2011, additional raw water capacity would need to be on line (beyond the current expansion that is underway), or have an alternative water supply identified and in place. Buildout of the County is not expected to occur at 2025, and for that reason additional water supply will be needed for future County development beyond that point. These future water supply concerns were the reason that the BOCC held a public workshop on December 6, 2006, with the St. Johns River Water Management District, the South Florida Water Management District, and their consultant, CDM, in attendance. At that meeting, the BOCC indicated that it was their desire to explore the following three alternative sources of water supply: Surficial Aquifer; Seawater Desalination; and Fresh Surface Water/Reservoirs. ES.2 Pros and Cons The pros and cons associated with each of the three treatment technologies and also the current use of the Upper Floridan Aquifer (UFA) are shown in Table ES-1 for comparison purposes. ES-1 N:\6706\IRC\WLB3130 EX Sum.doc

7 Executive Summary Table ES-1 Pros and Cons Associated with Alternative Water Supplies Pros Cons Surficial Aquifer Water is available Potentially lower cost than current water treatment technology No anticipated impact on agricultural wells in the UFA Different membrane treatment technology Deep injection well for disposal Production rates are low requiring a large number of wells Land acquisition of large number of well sites Potential wellfield protection issues because of shallowness of wells will require protection Variable water quality High maintenance Potential impact on adjacent homeowner wells Seawater Desalination Unlimited water availability Most expensive membrane treatment technologyenergy intensive Different membrane treatment technology Deep injection well for disposal If Boulder Zone is the source, then a study would be necessary to show feasibility Potentially a secure source if groundwater is the source; surface water source would be less secure Fresh Surface Water/Reservoirs Fresh surface water resources are abundant particularly at the boundary between the Upper Basin project and C-25 canal O&M costs are the lowest of all technologies Deep injection well not necessary Fellsmere Water Management Area (WMA) slated for development Different membrane treatment technology Approximately 20 miles of pipeline required Safe yields of the St. Johns River and Upper Basin project have not yet been determined minimum flows and levels in the St. Johns River must be met. Operational guidelines for the water conservation areas will be a constraint on available supply Timing of construction of Fellsmere WMA not determined Reconnection of the C- 25 canal and the Upper Basin project is still in the discussion stage. Source water will require protection Use of UFA Groundwater is available Ability to meet immediate and short term demands Same treatment technology as currently in place Costs are similar to existing costs Add on to existing treatment plants A secure source Potential interference with existing agricultural wells Deep injection well for disposal of concentrate Extension of well sites over greater distances to minimize drawdown impacts increases pipeline costs ES-2 N:\6706\IRC\WLB3130 EX Sum.doc

8 Executive Summary ES.3 Schedule for Implementation of Alternative Water Supplies As indicated in Table ES-2, a range of values is given for the implementation of each alternative water supply. The lower number of years represents the possibility that approvals for various permits would be processed routinely and that delays due to controversy or objections would not holdup the project. The higher number of years represents the time for working through various delays. The potential kinds of delaying activities that could occur are also shown in the table. The interim expanded use of the UFA is the lowest number of years because this represents the addition of infrastructure to existing facilities. Table ES-2 Schedule for Implementation of Alternative Water Supplies Number of Years to Implement from Authorization Potential delaying factors Surficial Aquifer Seawater Fresh Surface Interim Expanded Desalination Water/Reservoirs Use of UFA 6 to 8 6 to 10 6 to 10 2 to 4 1 Resolution of drawdown impacts on wells of adjacent home owners Groundwater quality protection Acquisition of large number of well sites 404 permitting for crossing of the Indian River Lagoon Feasibility study for use of the Boulder Zone as a source of water SJRWMD s determination of the safe yield of selected water storage areas Availability of water from the St. Johns River due to minimum flows and levels restrictions 1 This abbreviated time frame assumes use of existing infrastructure to install additional membranes rather than the construction of a new water treatment plant. ES.4 Costs of Alternative Water Supplies Resolution of drawdown impacts on nearby agricultural wells CDM has developed opinions of probable cost for the three different proposed sources using technologies appropriate for the sources. The cost of developing new water treatment plants and wellfields into the UFA has also been presented for comparison purposes. All costs are assumed to be current as of August 2006 unless otherwise indicated. They are considered to be order-of-magnitude estimates as defined by the American Association of Cost Engineers. These are estimates made without detailed engineering data. These opinions of probable cost are considered to be accurate within +50 percent or -30 percent for the components that are defined. No land acquisition costs are included in any of the opinions of probable cost. In the case of seawater desalination, CDM has included only the treatment costs and has not included the cost of an influent pipeline extending to the ocean because of significant uncertainties associated with this determination. CDM has developed opinions of probable capital, operation and maintenance (O&M), and total production costs for various potable water treatment technologies, treatment ES-3 N:\6706\IRC\WLB3130 EX Sum.doc

9 Executive Summary processes, and plant components. The general opinions of cost for these components are provided for plant capacity increments of 5, 10, 15, and 20 million gallons per day (mgd) on a maximum day demand (MDD) basis (Table ES-3). Table ES-3 presents a summary of the total production cost for each technology, including the annualized capital cost, the annual O&M costs for each production rate case, and an annual renewal and replacement (R&R) fund deposit (which is not included under O&M costs). The opinion of equivalent annual capital cost is the annual amortized cost based on an annual interest rate of 7 percent and 20-year amortization period. The annual R&R fund deposit is equal to 10 percent of the equivalent annual capital cost and is for replacement of major equipment that is expected to wear out over the 20- year service life of the plant. The annual production costs are given for the Annual Average Daily Demand (AADD) as opposed to the treatment plant capacity or maximum daily demand. ES.5 Ranking of Alternative Water Sources A strictly quantitative ranking of the alternative water supplies is not possible, but it is possible to make practical judgments regarding the three alternatives that have been proposed. All three alternative water supplies are positive with respect to water availability. All three, however, possess uncertainties and some level of risk. All three differ in cost, some significantly. The schedule for implementation is similar but the ability to implement any of the three would take a number of years. Seawater desalination is at this point the least desirable because it is the most expensive technology and most energy intensive. Use of saline groundwater from the Boulder Zone may be feasible but confirmation of this would be subject to a feasibility study that examined use of the Boulder Zone as both a source and disposal option. Development of the surficial aquifer presents some difficulties related to water quality protection since all of the wells would be very shallow with the most productive zones in the central part of the County in the upper 50 feet of the aquifer. Water quality variability is an issue. Low productivity means a large number of small wells producing small quantities of water. Impacts on adjacent users in the surficial aquifer may put the County in the same position as expanded use of the UFA with respect to agricultural wells. The County previously decided against using this source in the past (although used by the City of Vero Beach) and elected to go to the UFA. The UFA is a source with a consistent water quality that is protected from contamination and in which high capacity wells can be constructed. ES-4 N:\6706\IRC\WLB3130 EX Sum.doc

10 Executive Summary Table ES-3 Summary of Opinion of Probable Cost for Treatment Technologies Using Various Raw Water Sources Raw Water Source/ Treatment Method/ Plant Capacity (mgd) Raw Water Source Concentrate Disposal Capital Cost Annual O&M Cost Production Cost ($/1000 gallons) 4 Current Costs of UFA Using Low Pressure RO - Actual Costs (FY ) Surface Groundwater Water Discharge $1,551,882 $5,102,572 $2.05 Fresh Surface Water Using Microfiltration/Ultrafiltration 5 Surface Water N/A 2 $14,191,000 $1,078,000 $ Surface Water N/A 2 $24,397,000 $1,720,000 $ Surface Water N/A 2 $33,064,000 $2,289,000 $ Surface Water N/A 2 $41,025,000 $2,841,000 $1.22 Surficial Aquifer Using Nanofiltration 5 Groundwater Deep Injection Well $24,178,000 $1,646,000 $3.42 (DIW) 10 Groundwater DIW $33,576,000 $2,836,000 $ Groundwater DIW $41,573,000 $3,913,000 $ Groundwater DIW $50,188,000 $4,992,000 $1.75 Continued Use of UFA Using Low Pressure RO-New WTP and Wellfield 5 Groundwater DIW $34,693,000 $1,758,000 $ Groundwater DIW $48,579,000 $3,181,000 $ Groundwater DIW $64,086,000 $4,526,000 $ Groundwater DIW $79,077,000 $5,910,000 $2.42 Seawater RO Treatment Surface/ 3 DIW $39,429,000 $3,145,000 $5.95 Ground Water Surface/Ground 3 DIW $64,094,000 $6,230,000 $4.77 Water Surface/Ground 3 DIW $92,828,000 $9,248,000 $4.48 Water Surface/Ground 20 3 DIW $115,436,000 $12,432,000 $4.18 Water mgd is combined WTP capacity; actual average production for the FY is projected to be 8.89 mgd. Production cost based on actual average production estimate of 8.89 mgd (3,246 mgy) 2 MF/UF do not produce a concentrate steam as with nanofiltration and RO systems. Residuals need to be removed from the backwash water and chemicals in the backwash solution may require neutralization prior to disposal. 3 Costs include only treatment. Cost of an influent pipeline or deep well to the Boulder Zone as a source is not included. Deep Injection Well disposal would vary between $5.5 million and $11 million for the water treatment plant capacities presented. 4 Annual O&M and production costs are based on average daily demand using a maximum daily demand/annual average daily demand ratio. ES-5 N:\6706\IRC\WLB3130 EX Sum.doc

11 Executive Summary Fresh surface water located in western Indian River County represents a good first choice for a future long-range alternative water supply. Targeting fresh surface water as the County s long range source is a prudent course of action although not without risk. Water resources appear to be abundant and treatment is not as energy intensive as other technologies. Deep well injection would not be required, rather the disposal of residuals from the treatment process. After the initial construction of approximately 20 miles of pipeline that may cost from $10 million to $20 million, the operating cost would be low. The operating cost for the Tampa Bay fresh surface water treatment plant, a 66-mgd facility, is in the range of $0.40 per 1,000 gallons of finished water. The SJRWMD is evaluating the availability of water from the St. Johns River in view of minimum flows and levels and their evaluation will determine water availability in the existing and proposed water management areas. A significant amount of water that could be used for water supply has been identified in the C-25 canal basin and adjacent Upper St. Johns basin. This water is currently discharged to tide. Construction of a reservoir in the area of property owned by Cloud Grove to capture currently wasted water is in the discussion stage between SFWMD and SJRWMD. In addition, the proposed 10,000-acre Fellsmere WMA is potentially a significant additional source of fresh surface water. Decisions on the quantity and permittability of fresh surface water in western Indian River County will need to be made by SJRWMD prior to embarking on surface water as an alternative source. A great deal of coordination with SJRWMD will be necessary to determine the optimum location for withdrawals to ensure a sustainable withdrawal even during dry/drought periods. The use of Aquifer Storage and Recovery may be desirable as an additional storage vehicle to provide assurances of dry season water availability. If used as a source of public water supply, additional security will need to be provided to the surface water storage areas. In summary, this report recommends interim use of the UFA until 2017, at which time a long-range water supply will come on-line. This report recommends the pursuit of a surface water source as the long-range alternative supply for the County. ES.6 Potential for Interim Water Supply from the UFA Subsequent to the December 6, 2007, workshop, Kirby Green (Executive Director of SJRWMD) sent a letter, dated January 2, 2007, to the Honorable Gary Wheeler, Chairman of the BOCC, indicating the following: The SJRWMD has concluded that the UFA groundwater resources in Indian River County can sustain continued development through This information was based on the SJRWMD s 2003 water supply assessment. If the 2008 assessment indicates that the UFA cannot sustain proposed withdrawals through 2030, then ES-6 N:\6706\IRC\WLB3130 EX Sum.doc

12 Executive Summary the County will be identified as a priority water resource caution area and will become a focus of the next District (SJRWMD) Water Supply Plan. A new groundwater model designed for evaluations of withdrawals throughout the County and surrounding area should be ready for use in late spring This later model will be used in the 2008 District (SJRWMD) water supply assessment. SJRWMD suggested that the County investigate the feasibility of installing six new wells instead of three at the North Water Treatment Plant wellfield. These six wells could be spaced further apart and could be outfitted with lower capacity pumps. This would allow for the same production capacity but would reduce potential water level and water quality impacts. These wells could be constructed with 16- inch casing, according to SJRWMD, that would allow for installation of larger capacity pumps in the future should the potential issues with interference be resolved. SJRWMD recommends that County staff meet with SJRWMD staff to discuss the possibility of amending the County s current permit to provide for increased groundwater withdrawals at the south wellfield. As evident from Table ES-3, a conservative estimation of when an alternative water supply could be on line is 2017 or in ten years. Given that this is the case, an interim expansion of withdrawals from the UFA will be necessary. The max day raw water withdrawal amount in 2017 will need to be approximately 24 mgd. Current wellfield capacity is approximately 15.5 mgd (based on six wells at South County and three wells at North County). The interim expansion currently underway (to add three wells at North County) will increase this capacity to 20.7 mgd by late 2007 or early The 2017 demand will require the construction of three additional wells and three additional RO treatment skids prior to the time that a longterm supply can be placed on-line. Based on this assessment, the SJRWMD has given tentative direction, pending the conclusions of the 2008 District (SJRWMD) Water Supply Assessment, that the UFA can be an interim source of supply if the issues with adjacent users and potential drawdown interference are resolved. ES.7 Alternative Water Supply Master Plan Recommendations Based on the evaluation of the three possible alternative sources above, a new water treatment plant and supply source could not be on line for another six to ten years (2013 to 2017). For a surface water/reservoir source, it is possible that the decision may take longer if the prospective source is a reservoir that has not yet been constructed. A possible strategy for consideration by the BOCC is to continue to utilize the UFA as a source to bridge the gap until the new source can be developed. ES-7 N:\6706\IRC\WLB3130 EX Sum.doc

13 Executive Summary This strategy would be cost effective because it would continue to utilize existing treatment plant technology and facilities. At such time as the new source is on line, the withdrawals from the UFA could be reduced if that was desirable. If the approach discussed in this report is found to be acceptable by the BOCC, then the following actions are recommended: If the decision to continue using the UFA as an interim source is made until such time a surface water source can be brought on line, the County should proceed according to the direction given by SJRWMD above. SJRWMD suggested that the County investigate the feasibility of installing six new wells instead of three at the North Water Treatment Plant wellfield and that these six wells could be spaced further apart and could be outfitted with lower capacity pumps. This interim strategy should be discussed and coordinated with stakeholders in advance. A decision could then be made as to whether to modify the current application or proceed with the current application for water use and then apply for a modification of currently proposed permit once issued. The County should meet with SJRWMD to discuss utilization of fresh surface water from their existing water management and conservation areas. Specific target sources, water availability, permitting requirements, and pipeline routes should be addressed. Requirements for feasibility studies should be determined as required by SJRWMD. If the source is a new reservoir, then ownership of the reservoir, costs of land, and how these costs would be financed should be addressed. Based on discussions with SJRWMD, a preliminary schedule should be developed that addresses both interim expansion of the UFA and the annual steps needed to develop the new surface water supply by ES-8 N:\6706\IRC\WLB3130 EX Sum.doc

14 Section 1 Introduction Indian River County (County) began the process of expanding the North County Water Treatment Plant (WTP) in 2004 by authorizing its consultant, Camp Dresser & McKee Inc. (CDM), to design, bid, permit, and provide general services during construction to expand the WTP from 3.53 million gallons per day (mgd) to 6.43 mgd. This expansion was to be accomplished via the installation of two additional reverse osmosis (RO) skids (permeate capacity of 1.5 mgd each, 3 mgd total) in the existing process bay, construction of a new adjoining construction bay (sized to house an additional four RO skids (permeate capacity of 1.5 mgd each, 6 mgd total)), and installation of one RO skid in the new process bay. The County later amended the contract to include full buildout of the WTP, which consisted of a total of eight RO skids (four in existing bay and four in new bay). Full buildout would require the construction of six new Upper Floridan Aquifer (UFA) raw water production wells, each producing approximately 1,200 gallons per minute (1.7 mgd) for a combined total of 10.4 mgd to supplement the existing three wells onsite. The County enlisted the services of Post, Buckley, Schuh and Jernigan (PBS&J) to design and bid the construction of six production wells (1.7 mgd each) to supply the planned expansion. A consumptive use permit (CUP) was submitted to the St. Johns River Water Management District (SJRWMD) for the six new wells and the corresponding increase in allocation. As the project has progressed towards construction, concerns from local groups/citizens (Soil and Water Conservation District (SWCD), Agriculture Advisory Committee (AAC), etc.) have developed regarding the potential negative impacts that increased pumping from the proposed additional wells may have on neighboring artesian flow wells. More specifically, there are concerns that increased pumping from the County s wells in the north county wellfield may reduce artesian pressure and increase chloride concentrations (as a result of upconing of saline water) in neighboring wells. These concerned parties requested that the County reduce the reliance on the UFA and consider alternative water supplies to address future demands. The County then decided to amend the CUP application that was submitted for the six wells and only pursue three in the immediate future. Alternatives would then be explored to constructing the final three wells. This report is to serve as a master plan to evaluate the potential alternative supplies that are available to the County. In addition to exploring alternative supplies, the County has implemented a sampling program to monitor conditions in the aquifer in the area surrounding the WTP. In response to the concerns voiced by the various groups above, the County implemented a water quality sampling program that includes eight artesian wells on properties neighboring the North County WTP site, trending in the County s existing three production wells, and sampling of the County s UFA monitoring well (deep). These wells are sampled on a weekly basis with the intent of establishing a baseline condition for each well. These wells will continue to be sampled after the three new 1-1 N:\6706\IRC\WLB3130 Section1.doc

15 Section 1 Introduction UFA wells are placed into service and the results will be compared to the established baseline in order to evaluate the impacts, if any, on the neighboring existing legal users of the UFA. The program includes sampling field parameters for chlorides, total dissolved solids, ph, and conductivity. As an initial step in beginning the process of preparing the alternative water supply master plan, the County conducted a public workshop on December 6, 2006, which included participation from SJRWMD, South Florida Water Management District (SFWMD), the Board of County Commissioners (BOCC), County staff, CDM staff, and members of the public. At the workshop, SJRWMD presented potential supply options within the County, as well as providing a status update on the availability of water in the UFA, which is the County s current supply. The result of the workshop was a list of possible alternatives to the County s current interim plan of increasing withdrawals from the UFA. These included an evaluation of the following alternative sources: Surficial aquifer water withdrawals; Seawater desalination; and Fresh surface water withdrawals/reservoirs. 1-2 N:\6706\IRC\WLB3130 Section1.doc

16 Section 2 Objectives The County has recently experienced a period of extremely rapid growth. Between 2003 and 2006, the experienced growth far exceeded that of the anticipated growth. This period of accelerated growth has affected the population projections within the County that are used for the purposes of water supply planning. Population projections for the County through the year 2025 are presented in tabular format in Table 2-1 and shown graphically on Figure 2-1. Water demand and water withdrawal projections for the same period of time are also shown on Figures 2-2 and 2-3. In the year 2025, the County s projected average day and max day demands are mgd and mgd, respectively. The corresponding average and max day raw water withdrawal demands are mgd and mgd, respectively. The difference between demand and withdrawal lies in the fact that the raw water is treated using reverse osmosis and some water is discharged to waste as concentrate. Current WTP capacity at the South County WTP Plant is 8.57 mgd and at the North County WTP is 3.53 mgd. Total WTP capacity is currently 12.1 mgd. The maximum daily groundwater withdrawal from each wellfield currently permitted (Year 2020) is 4.83 mgd for the North County wellfield and 8.96 mgd for the South County wellfield (13.79 mgd total), as allocated to the County by SJRWMD. The average daily groundwater withdrawals are 3.45 mgd and 6.4 mgd for the North and South wellfields (9.85 mgd total), respectively. The CUP application currently on file with SJRWMD, for which a Temporary Consumptive Use Permit (TCUP) has been requested, is to increase the average daily withdrawals to mgd. With the completion of the interim expansion at the North County WTP, which is expected to adequately supply maximum day demands through 2017, the combined WTP capacity will be mgd (8.57 mgd at South and mgd at North). The projected shortfall between projected 2025 withdrawal demands (22.14) and the existing TCUP allocation (14.23) is 7.91 mgd on an average day basis. By applying a peaking factor of approximately 1.35 (the average of the peaking factors resulting from the above max and average values), the calculated max day withdrawal allocation in the TCUP would be mgd. The projected shortfall between the 2025 max day withdrawal (29.89) and the calculated max day withdrawal for the existing TCUP allocation (19.21) is mgd. Buildout of the County is not expected to occur at 2025, and for that reason additional water supply will be needed for future County development beyond N:\6706\IRC\WLB3130 Sec2.doc

17 Section 2 Objectives Table 2-1 St. Johns River Water Management District Planning Estimates and Projections Estimated Max Day Finish Water (MGal) Estimated Max Day Raw Water (MGal) Population ADF Finished ADF Raw Water Year Served Water(MGal) (MGal) , , , , , , , , , , , , , , , , , , , , Note: Max. day finish water is estimated as 1.35 times average day finish water Max. day raw water is estimated as 1.35 times average day raw water 2-2 N:\6706\IRC\WLB3130 Sec2.doc

18 Figure 2-1 Population Projections 200, , , , , ,000 80,000 60,000 40,000 20, Year Figure 2-1 Projected Population for the Indian River County Water Service Area Population

19 Figure 2-2 Projected Finished Water Demands Year ADF Finish Water Max Day Finish Water Figure 2-2 Projected Finished Water Demands MGal

20 Figure 2-3 Projected Raw Water Withdrawals Year ADF Raw Water Max Day Raw Water Figure 2-3 Projected Raw Water Withdrawals MGal

21 Section 2 Objectives These future water supply concerns were the reason that the BOCC held the December 6, 2006, workshop described in Section 1. Subsequent to the December 6, 2006, workshop, Kirby Green (Executive Director of SJRWMD) sent a letter (see Appendix A) dated January 2, 2007, to the Honorable Gary Wheeler, Chairman of the BOCC, indicating the following: The SJRWMD has concluded that groundwater resources in the County can sustain continued development through This information was based on the SJRWMD s 2003 assessment. If the 2008 assessment indicates that the UFA cannot sustain proposed withdrawals through 2030, then the County will be identified as a priority water resource caution area and will become a focus of the next District Water Supply Plan. The model prepared by Dr. David Toth has limited usefulness for evaluating the impacts of withdrawals throughout the County and surrounding areas. A new model designed for evaluations of withdrawals throughout the County and surrounding area should be ready for use in late spring This later model will be used in the 2008 District Water Supply Assessment. SJRWMD recommends that County staff meet with SJRWMD staff at the Palm Bay Service Center to discuss the possibility of amending the County s current permit to provide for increased groundwater withdrawals at the south wellfield. SJRWMD will coordinate with SFWMD regarding drawdown impacts to the south. SJRWMD suggests that the County investigate the feasibility of installing six new wells instead of three at the north wellfield. These six wells could be spaced further apart and could be outfitted with lower capacity pumps. This would allow for the same production capacity but would reduce potential water level and water quality impacts. These wells could be constructed with 16-inch casings, according to SJRWMD, that would allow for installation of larger capacity pumps in the future should the potential issues with interference be resolved. While SJRWMD has indicated that groundwater from the UFA is a potential source of water based on their 2025 assessment, the BOCC has expressed an interest in the alternative sources that could provide a long-range source of water supply beyond 2025 to the County. Based on the conclusions of the December 6, 2006, workshop held by the County BOCC, the BOCC expressed a desire to explore alternative sources of water. These additional sources include: Surficial aquifer; Seawater desalination; and Fresh surface water. 2-6 N:\6706\IRC\WLB3130 Sec2.doc

22 Section 2 Objectives The County has requested that CDM undertake an evaluation of the alternative sources above. For comparison purposes, additional expansion of the UFA will be compared. This analysis will include the following: CONCEPTUAL ANALYSIS The conceptual analysis will include identifying the pros and cons of each identified alternative, ease of permitting, distance of proposed alternative from existing treatment infrastructure, transmission corridors for pipeline routing, efficiency of treatment process, and the ability to convert existing treatment infrastructure to accommodate new source water. COST IMPACTS A planning-level comparison of costs to implement each alternative identified will be conducted. These cost estimates will include treatment costs, piping to/from the water plant from each alternative source, estimated operations and maintenance costs, and production costs. Costs associated with expansion of the existing plants into the UFA will be presented for comparison purposes. This analysis will serve as a basis of comparison for determining which option(s) could be considered further as an alternative to constructing additional UFA production wells. Costs associated with real estate acquisition and easements are not included in these costs. SCHEDULE OF IMPLEMENTATION After planning-level cost estimates are established, CDM will estimate the time frame necessary to implement each option. Development of implementation schedules will consider the construction time associated with pipelines and other infrastructure needed to tap into the source, including water treatment plant construction/ modifications, in-line booster pump stations (if needed) and/or storage tanks. Permitting issues will also be factored into the implementation schedule. SUMMARIZE OPTIONS CDM will summarize the results of the conceptual analysis, costs, and schedule and compile a ranking of the alternatives. 2-7 N:\6706\IRC\WLB3130 Sec2.doc

23 Section 3 Surficial Aquifer The surficial aquifer in the County has been investigated in three significant reports: Crain, et al. (1975), Schiner, et al. (1988), and most recently by Toth and Huang (1998). These reports have evaluated the capacity of the surficial aquifer as well as its water quality. The earliest report by Crain, et al., indicates that the surficial aquifer varies considerably in physical characteristics, permeability, and well yield from place to place in the County. The surficial aquifer is generally less than 100 feet thick throughout the County. The greatest potential yield is near the coast southward from Sebastian. This area includes Indian River Farms Water Control District and the Sebastian River Drainage District. Well yields range from 250 to 1,000 gallons per minute (gpm). The areas of moderate potential well yield (100 to 250 gpm) are in the east central part of the County and in the far western part, beyond Blue Cypress Lake. The St. Johns Marsh is the area of lowest potential yield. According to this report, the potential for development of the surficial aquifer for water supply is great but widely dispersed. Natural recharge averages 16 inches annually in the area of greatest potential well yield. Water quality was found by Crain, et al., to be highly variable in the surficial aquifer. The report indicates that outside of the drainage districts, chloride concentrations of the surficial aquifer are generally less than 250 mg/l, and total dissolved solids are less than 500 mg/l. Chloride is high in the water from wells near the Indian River lagoon, and salt water intrusion is a threat along the lagoon. Within the drainage districts, the quality of the surficial aquifer water depends on the extent to which the Floridan aquifer is used to irrigate. The Floridan aquifer has concentrations of salts that are much higher than the surficial aquifer. When crops are irrigated using Floridan aquifer water, the salts are left behind after the applied water is consumed by evapotranspiration. Consequently, the chloride and total dissolved solids concentrations are much higher in these areas. Toth and Huang from the SJRWMD investigated groundwater resources in Central Indian River County from the Brevard County line to the St. Lucie County line in an area that is generally west of the coast and east of Blue Cypress Lake except for the northern part of the study area. This study was undertaken to find an alternative source of irrigation water for periods when surface water from the Upper St. Johns River Basin project would be unavailable. SJRWMD drilled seven test holes and six wells in the surficial aquifer throughout their study area. The most productive portion of the surficial aquifer system in this area occurs in the upper 50 feet of the system and has a thickness of generally less than 30 feet. Toth and Huang estimated the production rate of 4-inch diameter wells. An evaluation of all of the test well data indicated that the average reasonable production rate of a 4-inch diameter well producing water from the study area averages about 74 gpm (0.107 million gallons per day). At this production rate, approximately 14 wells would be needed to equal 3-1 N:\6706\IRC\WLB3130 Sec 3.doc

24 Section 3 Surficial Aquifer the production capacity of one, 1,000-gpm production well that is constructed into the Floridan aquifer. Water quality for seven, surficial aquifer wells sampled ranged from 49 mg/l chloride to 601 mg/l chloride. Toth and Huang indicated that the high value may be the result of infiltration of water being discharged from a nearby, free-flowing well withdrawing water from the Floridan aquifer system. They concluded that wells constructed should be expected to require considerable maintenance to avoid reduction in rates of discharge caused by sedimentation and biological and mineral encrustation of the filtration screens. In their opinion, the surficial aquifer system appears to have limitations as an economically feasible source of water for citrus irrigation or frost-and-freeze protection in the study area. 3.1 Permitting of Withdrawals from the Surficial Aquifer Permitting of withdrawals would be subject to SJRWMD s approval. Concerns about impacts on existing uses would be a major concern because there are many local homeowner wells in the surficial aquifer. 3.2 Pros and Cons of the Surficial Aquifer Pros: Water is available from the surficial aquifer. Water is available generally throughout the County and adjacent to the existing treatment infrastructure. No anticipated impact on agricultural wells that are withdrawing from the Floridan aquifer. Cons: Well production rates are low, requiring a large number of wells. Acquisition of a large number of well sites would be necessary, resulting in high real estate costs. Water quality in the surficial aquifer varies considerably with some values beyond drinking water standards; the major concern is that water quality may be inconsistent from one well to the next. Wells are subject to high maintenance activities. Treatment would require nanofiltration, a different type of membrane treatment than exists at the current water plants, with potentially a different type of treatment train. 3-2 N:\6706\IRC\WLB3130 Sec 3.doc

25 Section 3 Surficial Aquifer Impacts on adjacent homeowner wells would be necessary to evaluate and possibly mitigate. Wellfield protection efforts would be necessary to protect the wells from contamination. A means to dispose of the concentrate from the nanofiltration plant would need to be permitted and constructed. 3.3 Cost Impacts For the treatment of surficial aquifer water, CDM has assumed the use of nanofiltration, a membrane treatment technology. CDM has developed opinions of probable capital, operation and maintenance (O&M), and total production costs for nanofiltration. Costs have been provided for plant capacity increments of 5, 10, 15, and 20 mgd on a maximum day demand (MDD) basis. Cost estimates are considered to be order-of-magnitude estimates, as defined by the American Association of Cost Engineers. This is an approximate estimate made without detailed engineering data. An order-of-magnitude estimate is considered to be accurate within +50 percent or -30 percent, and is typically used for planning purposes. Within this Section, the cost data set may be viewed as comprising costs for developing entirely new plants of various capacity ranges. The costs for finished water storage and high service pumping costs are not included in this analysis. The cost tables include development of the raw water supply that, in this case, consists of small diameter wells. Potentially, the development of 1 mgd of well capacity would require the construction of 10 small diameter wells. Development of a 5-mgd plant would require at a minimum 50 small diameter wells plus 10 additional wells for standby capacity (total of 60 wells). These cost estimates also include the permitting and construction of a deep injection well for concentrate disposal. These costs do not include the cost of land acquisition. The nanofiltration process is assumed to operate at an 85-percent recovery rate, with no raw water blend. The well costs are rough estimates of the costs of a large number of small diameter wells. Pretreatment includes raw water acidification, anti-scalant feed, and micron cartridge filtration. The membrane system includes stainless steel membrane feed pumps and feed piping, membrane skids (pressure vessels, skid piping, membrane elements, control valves, and instrumentation), a membrane cleaning system, and process piping. Post-treatment includes packed-tower type degasification, a caustic (NaOH) feed system for ph adjustment, and application of a corrosion inhibitor. It is assumed that application of post-treatment chemicals will be performed in the clearwell (provided under the intermediate storage cost item). Pre-treatment and post- 3-3 N:\6706\IRC\WLB3130 Sec 3.doc

26 Section 3 Surficial Aquifer treatment chemical systems include bulk storage tanks and containment basins, day tanks, metering pumps, chemical piping, and chemical injection quills and/or diffusers. 3.4 Opinions of Capital Cost Table 3-1 presents the opinion of probable capital cost. Individual process and plant component cost items are listed first, followed by general plant improvements (e.g., yard piping, electrical, instrumentation and controls), which are estimated by a factor applied to the process/plant component subtotal. The contractor s administrative costs follow (i.e., general requirements, overhead and profit, and construction contingency). The opinion of probable construction cost is presented as a subtotal. This cost may be considered to be comparable to a general contractor s bid cost for a traditional design-bid-build project delivery method. The owner s costs are presented following the opinion of probable construction cost. These include technical services (e.g., engineering design, permitting, surveying, geotechnical engineering, engineering services during construction, etc.), owner administration and legal (e.g., internal expenses associated with project management and administration), and project contingency (for unknowns related to design conditions, water quality, etc.). The total opinion of probable capital cost is presented as the sum of the above items. The opinion of equivalent annual capital cost is then presented below in Table 3-1, which is the annual amortized cost based on an annual interest rate of 7 percent and 20-year amortization period. 3.5 Opinions of Operation and Maintenance Cost Table 3-2 presents the annual O&M cost for this technology. Within this table, these costs are broken up into variable and fixed costs. Variable costs include items such as power, chemicals, and replacement parts and materials. These costs vary in proportion to the amount of finished water produced by the plant over the study year. Fixed costs include labor (plant staffing) and administration/regulatory compliance, which are independent of the water production rate. Within Table 3-2, total annual O&M costs are presented for two cases. In the first case, variable costs are based on the plant capacity rating (i.e., for the 5-mgd capacity plant, variable costs are based on a 5-mgd production rate, 24 hours per day, 365 days per year). Essentially, this case assumes that the plant is operating at capacity all of the time. 3-4 N:\6706\IRC\WLB3130 Sec 3.doc

27 Table 3-1 Opinion of Probable Capital Cost Treatment Technology : Nanofiltration August 2006 Dollars Item Allowance Plant Capacity (mgd) No. Description Factor Raw water supply $1,200,000 $2,400,000 $3,300,000 $4,500, Pretreatment $87,000 $146,000 $213,000 $268, Process equipment $1,919,000 $3,227,000 $4,396,000 $5,534, Post treatment $224,000 $377,000 $513,000 $646, Intermediate storage (clearwell) $110,000 $208,000 $305,000 $400, Transfer pumping $105,000 $160,000 $194,000 $248, Plant infrastructure $1,371,000 $2,306,000 $3,142,000 $3,955, Concentrate disposal $5,500,000 $5,500,000 $5,500,000 $5,500,000 Subtotal: $10,516,000 $14,324,000 $17,563,000 $21,051, Yard piping 7% $736,000 $1,003,000 $1,229,000 $1,474, Electrical(1) 10% $502,000 $882,000 $1,206,000 $1,555, Instrumentation and controls(1) 7% $351,000 $618,000 $844,000 $1,089, Site work 5% $526,000 $716,000 $878,000 $1,053,000 Subtotal: $12,631,000 $17,543,000 $21,720,000 $26,222, General Requirements 2% $253,000 $351,000 $434,000 $524, Contractor overhead and profit 15% $1,895,000 $2,631,000 $3,258,000 $3,933, Construction contingency 15% $1,895,000 $2,631,000 $3,258,000 $3,933,000 Opinion of Probable Construction Cost: $16,674,000 $23,156,000 $28,670,000 $34,612, Technical Services 25% $4,169,000 $5,789,000 $7,168,000 $8,653, Owner administration and legal 5% $834,000 $1,158,000 $1,434,000 $1,731, Project contingency 15% $2,501,000 $3,473,000 $4,301,000 $5,192,000 Opinion of Probable Capital Cost: $24,178,000 $33,576,000 $41,573,000 $50,188,000 Opinion of Equivalent Annual Capital Cost: $2,282,232 $3,169,337 $3,924,197 $4,737,392 Plant service life = 20 years Annual interest rate = 7% Unit Probable Construction Cost ($/gpd) $3.33 $2.32 $1.91 $1.73 Unit Probable Total Capital Cost ($/gpd) $4.84 $3.36 $2.77 $2.51 Notes: (1) "Electrical" and "Instrumentation and controls" cost items are estimated as 10% and 7%, respectively, of the subtotal of the preceding cost components minus the cost for concentrate disposal. This is due to the fact that a concentrate disposal deep injection well (DIW) has negligible electrical and instrumentation and controls costs relative to other plant components, while the construction cost for a DIW is typically a substantial portion of the total facility cost. N:\6706\IRC\WLB 3097 Sec 3 Tables.xls

28 Table 3-2 Opinion of Annual Operation and Maintenance Cost Treatment Technology : Nanofiltration August 2006 Dollars Assumptions Unit power cost = $0.10 per kw-hr Item Plant Capacity (mgd) No. Description Variable Costs 1. Power $477,000 $954,000 $1,431,000 $1,908, Chemicals $293,000 $492,000 $667,000 $828, Replacement parts and materials $432,000 $726,000 $984,000 $1,221,000 a. Replacement membranes: $110,000 $185,000 $250,000 $311,000 Fixed 4. Operation and maintenance labor $459,000 $565,000 $638,000 $695, Administration/regulatory compliance $312,000 $525,000 $712,000 $883,000 Annual Production at Rated Capacity, (mgy) 1,825 3,650 5,475 7,300 Annual O&M Cost at Rated Capacity $2,083,000 $3,447,000 $4,682,000 $5,846,000 Unit Cost at Rated Capacity, $/kgal $1.14 $0.94 $0.86 $0.80 Annual Production at Avg Day Demand, (mgy) 1,217 2,704 4,212 5,840 Annual O&M Cost at ADD Capacity $1,646,000 $2,836,000 $3,913,000 $4,992,000 Unit Cost at Rated Capacity, $/kgal $1.35 $1.05 $0.93 $0.85 N:\6706\IRC\WLB 3097 Sec 3 Tables.xls

29 Section 3 Surficial Aquifer In the second case, the variable costs are based on the plant meeting an annual average day demand (AADD), which is estimated as a factor of the plant capacity rating. It should be noted that the typical plant capacity rating is based on meeting a MDD. The methodology for estimating the AADD based on the MDD utilizes an assumed MDD/AADD peaking factor. This peaking factor is a characteristic of the distribution system served by a plant, and is related to the size of the system (i.e., the plant capacity rating). The MDD/AADD factor generally decreases as the size of the system increases. Assumptions for MDD/AADD are based on CDM experience and are listed in Table 3-2. The AADD for a given plant capacity is calculated as follows: AADD = [Plant Capacity (mgd)] / [MDD/AADD] For the 5-mgd plant capacity rating, the estimated AADD is: AADD = 5 mgd / 1.50 = 3.33 mgd or 1,217 million gallons per year (mgy) The above calculation is summarized for each case in each table and defines the basis for the variable costs for the AADD case. The O&M costs presented here are typical of larger diameter wells. Thus, the actual costs for a larger number of small diameter wells may be at the upper range of the probable costs or +50 percent. 3.6 Opinions of Total Production Costs Table 3-3 presents a summary of the total production cost for nanofiltration, including the annualized capital cost from Table 3-1, the annual O&M costs for each production rate case presented in Table 3-2, and an annual renewal and replacement (R&R) fund deposit (which is not included under O&M costs). The annual R&R fund deposit is equal to 10 percent of the equivalent annual capital cost and is for replacement of major equipment that is expected to wear out over the 20-year service life of the plant. As with the O&M costs, annual production costs are given for two cases, production equal to the plant capacity rating, and production equal to the AADD estimated as discussed above for the O&M cost tables. 3.7 Schedule of Implementation The time frame for well site acquisition, permitting, design and construction of a new nanofiltration facility, production wells, and deep injection well for concentrate disposal is expected to be six to eight years from authorization to proceed. Delays in the acquisition of well sites may cause the project to be delayed beyond this time frame because of the large number of well sites required. Likewise, if mitigation of impacts on adjacent uses is required, additional delays may be encountered. 3-7 N:\6706\IRC\WLB3130 Sec 3.doc

30 Table 3-3 Opinion of Total Production Cost Treatment Technology : Nanofiltration August 2006 Dollars Item Plant Capacity (mgd) No. Description Production Costs at Rated Capacity 1. Equivalent annual capital cost $2,282,000 $3,169,000 $3,924,000 $4,737, Annual O&M Cost - Variable $1,312,000 $2,357,000 $3,332,000 $4,268, Annual O&M Cost - Fixed $771,000 $1,090,000 $1,350,000 $1,578, Annual R&R fund deposit(1): $228,000 $317,000 $392,000 $474,000 Total Annual Cost: $4,593,000 $6,933,000 $8,998,000 $11,057,000 Annual Production at Rated Capacity, (mgy) 1,825 3,650 5,475 7,300 Annual Production Cost at Rated Cap. ($/kgal): $2.52 $1.90 $1.64 $1.51 Production Costs at Average Day Demand (ADD) MDD/AADD factor(2): Equivalent annual capital cost $2,282,000 $3,169,000 $3,924,000 $4,737, Annual O&M Cost - Variable $875,000 $1,746,000 $2,563,000 $3,414, Annual O&M Cost - Fixed $771,000 $1,090,000 $1,350,000 $1,578, Annual R&R fund deposit(1): $228,000 $317,000 $392,000 $474,000 Total Annual Cost: $4,156,000 $6,322,000 $8,229,000 $10,203,000 Annual finished water production rate (mgy)(3): 1,217 2,704 4,212 5,840 Annual Production Cost at ADD ($/kgal): $3.42 $2.34 $1.95 $1.75 Notes: (1) Annual deposit to a renewal and replacement (R&R) fund is equal to 10% of the equivalent annual capital cost. (2) Maximum day demand (MDD, equal to the plant capacity rating) divided by the annual average daily demand (AADD). This factor is used to calculate the AADD to be used in the calculation of the annual production cost. (3) Annual finished water production rate in million gallons per year (mgy) is equal to the AADD (mgd) times 365 days. N:\6706\IRC\WLB 3097 Sec 3 Tables.xls

31 Section 4 Seawater Desalination In order to provide some background on seawater desalination RO in Florida, CDM has provided some of the details of the development of the Tampa Bay Water RO facility, a unique facility in Florida. The Tampa Bay Water RO facility operates adjacent to a power plant and utilizes the existing cooling water intake for the power plant and the concentrate is discharged to the cooling water outfall. The contract for this facility was originally awarded by Tampa Bay Water (TBW) to a consortium consisting of Poseidon Resources and Stone and Webster Engineering on a design, build, operate, and finance (DBOF) basis in July of Under this contract, the Developer, Poseidon Resources, guaranteed to produce and sell 25 mgd of desalinated water for a contract term of 30 years. Stone and Webster was replaced by Covanta in The original scheduled completion date for construction of the project was December of The project is still undergoing modifications. The facility is located north of the cooling water inlet canal for the Tampa Electric Company Big Bend Power Station. An agreement was reached that allowed the Developer to lease this industrial zoned site from Tampa Electric for the duration of the Project. The RO plant is designed to produce a guaranteed water quality having finished water chlorides of less than 100 mg/l. To accomplish this stringent water quality objective, the treatment process includes a first pass of RO membranes and a partial second pass of brackish RO membranes. The percentage of the flow stream directed to the second pass is varied to meet the specified product water quality. The seawater reverse osmosis system consists of seven seawater RO membrane units. The units are sized such that six units are capable of producing the plant rated capacity of 25 mgd. The seventh unit is essentially an installed spare, and the total installed membrane capacity of the facility is approximately 29 mgd. The source water for the facility is taken from the cooling water discharge conduits of the power station and the facility essentially reuses the water withdrawn by Tampa Electric from Tampa Bay. The cooling water (greater than 1,350 mgd) flows to the power plant through an inlet canal, is drawn into two intake structures, is screened, pumped through the main condensers of the plant, and is discharged through outfalls into another canal for transport back to the Bay. The concentrate and filter backwash water discharged from the RO plant are discharged into the cooling water outfalls along with the discharge from the power plant. The original pretreatment system utilizes two-stage, Dyna-Sand type gravity filtration with chemical addition. This pretreatment system has experienced operational problems and is currently in the process of being upgraded. Water from the pretreatment system is pumped by vertical turbine pumps from the pretreatment clearwell through the cartridge filter to the first pass seawater RO units described 4-1 N:\6706\IRC\WLB3130 Sec 4.doc

32 Section 4 Seawater Desalination above. The product water is then pumped approximately fourteen miles to the Tampa Bay Water regional water plant. CDM s summary of probable cost for the Tampa Bay seawater reverse osmosis surface water plant is shown in Tables 4-1, 4-2, and 4-3. The difference between Tampa Bay Water s RO facility and a facility in the County is the current inability to co-locate with a power plant because such a plant does not exist in the County. For this reason, a seawater RO facility in the County will require additional costs associated with developing a source of seawater and a means of concentrate disposal. Two possible sources exist: a seawater influent pipeline and a deep well to the boulder zone. Water in the boulder zone is seawater. In either case, concentrate disposal could be via deep injection well; although, if a deep injection well is used for disposal, the source well and the disposal well must be separated by a significant distance. The cost of an influent surface water pipeline has not been estimated at this time. There is no proposed location for a seawater RO facility, and the pipeline would need to extend across the Indian River Lagoon, the island area of the County, and out into the ocean for an unknown distance. If a deep well to the Boulder zone is feasible and it is used as a source of water, the additional cost is on the order of $5.5 million to $11 million for plants varying from 5 to 20 mgd. The additional cost of deep well injection of concentrate would range from $5.5 to $11 million for either one or two wells, depending on the size of the plant. The sea water RO process is assumed to operate at a 50 percent recovery rate, and for that reason a significant amount of concentrate would be produced. Additional pipeline costs would be incurred if deep wells were used both as the source water and for the disposal of concentrate because of the need to separate the two by a significant distance. For a seawater RO facility in the County, the pretreatment, process, and posttreatment components are essentially the same as described in Section 3 for the nanofiltration system (with differences in items such as pipe pressure ratings due to the difference in operating pressures). However, an additional pretreatment step of media filters would be provided upstream of the cartridge filters due to higher levels of suspended particulate contaminants present in a surface water supply. 4.1 Permitting of Seawater Desalination Surface seawater withdrawals are not normally permitted by water management districts. A seawater influent pipeline crossing the Indian River Lagoon and the area offshore would require a 404 permit from the U.S. Army Corps of Engineers and various permits from the Florida Department of Environmental Protection (FDEP). Obtaining these permits may be controversial and result in delays of the project. 4-2 N:\6706\IRC\WLB3130 Sec 4.doc

33 Table 4-1 Summary of Capital Cost Treatment Technology : Tampa Bay Water Seawater RO Escalated Original Aug-06 Item Allowance Plant Capacity (mgd) No. Description Factor Raw water supply $921,000 $1,183, Pretreatment $7,747,000 $9,949, Process equipment $17,604,000 $22,607, Post treatment $357,000 $458, Intermediate storage (clearwell) $470,000 $604, Transfer pumping $0 $0 7. Finished water storage $2,431,000 $3,122, High service pumping $403,000 $518, Plant infrastructure $5,542,000 $7,117, Concentrate disposal $802,000 $1,030,000 Subtotal: $36,277,000 $46,588, Yard piping $4,723,000 $6,065, Mechanical $14,000,000 $17,979, Electrical $3,724,000 $4,782, Instrumentation and controls $1,486,000 $1,908, Site work $1,785,000 $2,292,000 Subtotal: $61,995,000 $79,614, General Requirements $1,952,000 $2,507, Contractor overhead and profit $5,785,000 $7,429, Construction contingency $1,882,000 $2,417,000 Opinion of Probable Construction Cost:: $71,614,000 $91,967, Developer's Costs $10,631,000 $13,652, Bonds, Insurance, Capitalized Construction Interest $8,081,000 $10,378, Controlled Insurance Program $4,500,000 $5,779,000 Opinion of Probable Capital Cost: $94,826,000 $121,776,000 Opinion of Equivalent Annual Capital Cost: $8,950,904 $11,494,793 Plant service life = 20 years Annual interest rate = 7% Unit Probable Construction Cost ($/gpd) $2.47 $3.17 Unit Probable Total Capital Cost ($/gpd) $3.27 $4.20 N:\6706\IRC\WLB3097 Sec 4 Tables.xls

34 Table 4-2 Summary of Annual Operation and Maintenance Cost Treatment Technology : Tampa Bay Water Seawater RO August 2006 Dollars Assumptions Unit power cost = $0.10 per kw-hr Item Plant Capacity (mgd) No. Description 25 Variable Costs 1. Power $22,813, Chemicals $1,036, Replacement parts and materials $1,260,000 a. Replacement membranes: $1,004,000 Fixed 4. Operation and maintenance labor $953, Administration/regulatory compliance $1,120,000 Annual Production at Rated Capacity, (mgy) 9,125 Annual O&M Cost at Rated Capacity $28,186,000 Unit Cost at Rated Capacity, $/kgal $3.09 Annual Production at Avg Day Demand, (mgy) 7,300 Annual O&M Cost at ADD Capacity $22,963,000 Unit Cost at Rated Capacity, $/kgal $3.15 N:\6706\IRC\WLB3097 Sec 4 Tables.xls

35 Table 4-3 Summary of Total Production Cost Treatment Technology : Tampa Bay Water Seawater RO August 2006 Dollars Item Plant Capacity (mgd) No. Description 25 Production Costs at Rated Capacity 1. Equivalent annual capital cost $11,495, Annual O&M Cost - Variable $26,113, Annual O&M Cost - Fixed $2,073, Annual R&R fund deposit(1): $1,150,000 Total Annual Cost: $40,831,000 Annual Production at Rated Capacity, (mgy) 9,125 Annual Production Cost at Rated Cap. ($/kgal): $4.47 Production Costs at Average Day Demand (ADD) MDD/AADD factor(2): Equivalent annual capital cost $11,495, Annual O&M Cost - Variable $20,890, Annual O&M Cost - Fixed $2,073, Annual R&R fund deposit(1): $1,150,000 Total Annual Cost: $35,608,000 Annual finished water production rate (mgy)(3): 7,300 Annual Production Cost at ADD ($/kgal): $4.88 Notes: (1) Annual deposit to a renewal and replacement (R&R) fund is equal to 10% of the equivalent annual capital cost. (2) Maximum day demand (MDD, equal to the plant capacity rating) divided by the annual average daily demand (AADD). This factor is used to calculate the AADD to be used in the calculation of the annual production cost. (3) Annual finished water production rate in million gallons per year (mgy) is equal to the AADD (mgd) times 365 days. N:\6706\IRC\WLB3097 Sec 4 Tables.xls

36 Section 4 Seawater Desalination Mitigation may be required if sea grasses are filled in the process of pipeline installation. These may lead to additional costs and time delays in project construction. Withdrawals from the Boulder zone may be subject to permitting by the SJRWMD. Permitting of Boulder Zone withdrawals and disposal, in contrast, could be much simpler, provided that assurances could be given that the two would not interfere with one another: the water in the Boulder Zone would not be affected by injectate from industrial disposal wells (one of which is located in the southern part of the County), and that the water quality in the Boulder Zone is consistently seawater quality. A feasibility study would be required to show that these conditions exist. 4.2 Pros and Cons of Seawater Desalination Pros: Seawater is available and potentially unlimited in quantity. Cons: Seawater RO is the most expensive treatment process for potable water development. The Tampa Bay Seawater RO plant, the only plant of this type in Florida, experienced a great deal of difficulty in start-up and is not yet fully operational. If surface seawater is the source and there is a crossing of the Indian River Lagoon, then crossing the Indian River Lagoon, the island, and offshore beach to install an influent pipeline may lead to objections from both environmentalists and homeowners; additional mitigation and costs may be required as a consequence of damage to sea grasses in the Lagoon. If the Boulder Zone is a potential source, a feasibility study would be necessary to demonstrate separation from the disposal zone, water quality is consistent, and the source would not be impacted by industrial disposal elsewhere in the County. This would add additional time and cost to the project. 4.3 Cost Impacts Plant sizes smaller than the Tampa Bay Water Seawater RO plant are feasible, and the costs associated with plants of 5, 10, 15, and 20 mgd are shown in Tables 4-4, 4-5, and 4-6. These costs do not include source and concentrate disposal costs. If surface seawater is the source, then a pipeline to the ocean would be necessary. If the Boulder zone is feasible as a source of seawater, then a supply well (s) could cost an additional $11 million. Also, costs presented do not include additional costs for deep injection well disposal that could cost $5.5 million to $11 million more depending on plant size. 4-6 N:\6706\IRC\WLB3130 Sec 4.doc

37 Table 4-4 Opinion of Probable Capital Cost Treatment Technology : Seawater RO August 2006 Dollars Item Allowance Plant Capacity (mgd) No. Description Factor Raw water supply $2,263,000 $3,676,000 $4,982,000 $6,182, Pretreatment $2,718,000 $4,415,000 $6,583,000 $8,242, Process equipment $8,229,000 $13,368,000 $19,930,000 $24,730, Post treatment $561,000 $912,000 $1,236,000 $1,534, Intermediate storage (clearwell) $110,000 $208,000 $305,000 $400, Transfer pumping $105,000 $160,000 $194,000 $248, Plant infrastructure $1,921,000 $3,120,000 $4,229,000 $5,247, Concentrate disposal $0 $0 $0 $0 Subtotal: $15,907,000 $25,859,000 $37,459,000 $46,583, Yard piping 7% $1,113,000 $1,810,000 $2,622,000 $3,261, Electrical 10% $1,591,000 $2,586,000 $3,746,000 $4,658, Instrumentation and controls 7% $1,113,000 $1,810,000 $2,622,000 $3,261, Site work 5% $795,000 $1,293,000 $1,873,000 $2,329,000 Subtotal: $20,519,000 $33,358,000 $48,322,000 $60,092, General Requirements 2% $410,000 $667,000 $966,000 $1,202, Contractor overhead and profit 15% $3,078,000 $5,004,000 $7,248,000 $9,014, Construction contingency 15% $3,078,000 $5,004,000 $7,248,000 $9,014,000 Opinion of Probable Construction Cost:: $27,085,000 $44,033,000 $63,784,000 $79,322, Technical Services 25% $6,771,000 $11,008,000 $15,946,000 $19,831, Owner administration and legal 5% $1,354,000 $2,202,000 $3,189,000 $3,966, Project contingency 15% $4,063,000 $6,605,000 $9,568,000 $11,898,000 Opinion of Probable Capital Cost: $39,273,000 $63,848,000 $92,487,000 $115,017,000 Opinion of Equivalent Annual Capital Cost $3,707,093 $6,026,800 $8,730,119 $10,856,791 Plant service life = 20 years Annual interest rate = 7% Unit Probable Construction Cost ($/gpd) $5.42 $4.40 $4.25 $3.97 Unit Probable Total Capital Cost ($/gpd) $7.85 $6.38 $6.17 $5.75 Notes: $3.38/gpd for Construction 20 mgd looks low Pretreatment looks low Above figures do not include residuals management N:\6706\IRC\WLB3097 Sec 4 Tables.xls

38 Table 4-5 Opinion of Annual Operation and Maintenance Cost Treatment Technology : Seawater RO August 2006 Dollars Assumptions Unit power cost = $0.10 per kw-hr Item Plant Capacity (mgd) No. Description Variable Costs 1. Power $2,537,000 $5,073,000 $7,610,000 $10,146, Chemicals $338,000 $676,000 $1,014,000 $1,352, Replacement parts and materials $595,000 $1,001,000 $1,356,000 $1,683,000 a. Replacement membranes: $92,000 $185,000 $277,000 $370,000 Fixed 4. Operation and maintenance labor $459,000 $565,000 $638,000 $695, Administration/regulatory compliance $310,000 $525,000 $715,000 $891,000 Annual Production at Rated Capacity, (mgy) 1,825 3,650 5,475 7,300 Annual O&M Cost at Rated Capacity $4,331,000 $8,025,000 $11,610,000 $15,137,000 Unit Cost at Rated Capacity, $/kgal $2.37 $2.20 $2.12 $2.07 Annual Production at Avg Day Demand, (mgy) 1,217 2,704 4,212 5,840 Annual O&M Cost at ADD Capacity $3,144,000 $6,227,000 $9,243,000 $12,427,000 Unit Cost at Rated Capacity, $/kgal $2.58 $2.30 $2.19 $2.13 N:\6706\IRC\WLB3097 Sec 4 Tables.xls

39 Table 4-6 Opinion of Total Production Cost Treatment Technology : Seawater RO August 2006 Dollars Item Plant Capacity (mgd) No. Description Production Costs at Rated Capacity 1. Equivalent annual capital cost $3,707,000 $6,027,000 $8,730,000 $10,857, Annual O&M Cost - Variable $3,562,000 $6,935,000 $10,257,000 $13,551, Annual O&M Cost - Fixed $769,000 $1,090,000 $1,353,000 $1,586, Annual R&R fund deposit(1): $371,000 $603,000 $873,000 $1,086,000 Total Annual Cost: $8,409,000 $14,655,000 $21,213,000 $27,080,000 Annual Production at Rated Capacity, (mgy) 1,825 3,650 5,475 7,300 Annual Production Cost at Rated Cap. ($/kgal): $4.61 $4.02 $3.87 $3.71 Production Costs at Average Day Demand (ADD) MDD/AADD factor(2): Equivalent annual capital cost $3,707,000 $6,027,000 $8,730,000 $10,857, Annual O&M Cost - Variable $2,375,000 $5,137,000 $7,890,000 $10,841, Annual O&M Cost - Fixed $769,000 $1,090,000 $1,353,000 $1,586, Annual R&R fund deposit(1): $371,000 $603,000 $873,000 $1,086,000 Total Annual Cost: $7,222,000 $12,857,000 $18,846,000 $24,370,000 Annual finished water production rate (mgy)(3): 1,217 2,704 4,212 5,840 Annual Production Cost at ADD ($/kgal): $5.94 $4.76 $4.47 $4.17 Notes: (1) Annual deposit to a renewal and replacement (R&R) fund is equal to 10% of the equivalent annual capital cost. (2) Maximum day demand (MDD, equal to the plant capacity rating) divided by the annual average daily demand (AADD). This factor is used to calculate the AADD to be used in the calculation of the annual production cost. (3) Annual finished water production rate in million gallons per year (mgy) is equal to the AADD (mgd) N:\6706\IRC\WLB3097 Sec 4 Tables.xls

40 Section 4 Seawater Desalination 4.4 Schedule of Implementation The time frame for permitting, design, and construction of a new seawater RO facility, water source, and deep injection wells for disposal is expected to be on the order of six to ten years from authorization. If a surface source of seawater is desired, the longer time frame would likely be more accurate because of potential objections to a pipeline crossing of the Indian River Lagoon and finding a route across the barrier island that would not also result in homeowner objections N:\6706\IRC\WLB3130 Sec 4.doc

41 Section 5 Fresh Surface Water/Reservoirs There are significant fresh water resources within the County that are potentially available for use as a potable water supply. As a result of the US Army Corps of Engineers Upper St. Johns River Basin project, a number of both water management and water conservation areas have been constructed within the County to capture and store fresh water that would otherwise be discharged to tide. These include: Blue Cypress Water Management Area East; Blue Cypress Water Management Area West; Blue Cypress Marsh Conservation Area; Fort Drum Marsh Conservation Area; and St. Johns Water Management Area. A map showing these areas is presented on Figure 5-1. SJRWMD has also just recently acquired the 10,000-acre parcel that will be converted to the Fellsmere Water Management Area, a proposed water storage reservoir that will be managed by SJRWMD. This area is also shown in Figure 5-1. In addition to SJRWMD reservoir projects shown on Figure 5-1, SJRWMD and SFWMD jointly contracted for a study to establish the benefits and feasibility of reconnecting the Upper St. Johns River basin with the C-25 basin (located within SFWMD) and establishing storage at that location. A summary of this project is contained in Appendix B (PBS&J, 2006). The study found that there is a statistically significant difference in rainfall between rainfall stations at Vero Beach and Ft. Pierce, with up to 10 feet of cumulative difference in rainfall over a 35-year period between stations. This study also examined discharges to tide out of five different basins including the St. Johns Water Control District, Ft. Pierce Farms Water Control District, IRFWCD South Relief Canal, IRFWCD Main Relief Canal, and S-50 that drains the SFWMD s C-25 Canal (see maps in Appendix B and Figure 5-2). The study showed that just three of the five control points (S-50, South Relief Canal and Main Relief Canal) discharged millions of acre-feet of freshwater over the past 50 years from manmade ditches and channels. The median annual discharge for these three structures from 1965 to 2004 was 204,661 acre-feet (ac-ft). The minimum was 82,978 ac-ft. The maximum was 364,541 ac-ft. 5-1 N:\6706\IRC\WLB3130 Sec 5.doc

42 FLORIDA, USA Fellsmere Water Management Area Blue Cypress Marsh Conservation Area Fort Drum Marsh Conservation Area I95 North WTP US 1 South WTP St. Johns Water Management Area Blue Cypress Water Management Area - E Blue Cypress Water Management Area - W Legend Conservation Area (CA) Water Management Area (WMA) South County WTP North County WTP County Boundary Potential Surface Water Reservoir Cloud Grove (Potential Surface Water Resevoir) 0 10,000 20,000 40,000 Feet 1 inch equals 3 miles Figure 5-1 Indian River County Surface Water Basins

43 FLORIDA, USA C-54 Canal la At ce a n Indian River County ic O I 95 Sebastian Water Control District nt Fellsmere Water Control District US 1 North Relief Canal (M tral Cen St. Johns River Water Control District C-52 Canal Re a in ) an a lief C Re South l lief Ca n al Indian River Farms Water Control District Ft. Pierce Farms Water Control District S50 C-25 Canal Legend S50 Spillway South County WTP North County WTP Fellsmere Water Control District Sebastian Water Control District North St. Lucie River Water Control District Indian River Farms Water Control District St. Johns River Water Control District Ft. Pierce Farms Water Control District North St. Lucie River Water Control District County Boundary Canals St. Lucie County 0 12,500 25,000 50,000 Feet 1 inch equals 5 miles Figure 5-2 Indian River and St. Lucie County Water Control Districts

44 Section 5 Fresh Surface Water/Reservoirs From interviews of past reports, it appears that more than 22,000 acres of suitable land may be available for purchase in the study area to accommodate one or more large reservoir storage areas. The study also concluded that the network of drainage ditches and canals necessary to connect these flows to storage areas already exists. A simulation was conducted involving the filling of a 30,000-acre reservoir to a depth of 30 feet over a period of 40 years using available water from only the S-50 spillway pumped at a continuous rate of 1000 cubic feet per second (cfs). This latter flow constitutes 93 percent of the available freshwater; this was not done as a practical exercise of the amount that could actually be stored but of the amount of water that would be available from just one basin. In addition to the surface water projects being developed by the two water management districts, a development project in northern St. Lucie County also presents a possible opportunity for a reservoir site. Recently, the Florida Conservancy and Development Group, LLC, applied to St. Lucie County for a Development of Regional Impact for a project known as Cloud Grove. The project overlaps both St. Lucie and Indian River Counties in the vicinity of the proposed reconnection. The majority of the development would occur in the portion of the project site within St. Lucie County. However, there is a portion of the project site, approximately 1,400 acres that lies just north of the County line in Indian River County. The suggestion has been made that the 1,400 acre parcel be considered for use as a reservoir. As indicated above, there is sufficient water available from C-25, IRFWCD South Relief Canal, and IRFWCD Main Relief Canal to fill a reservoir on the 1,400-acre parcel. The location of the 1,400 acre site is also shown on Figure Permitting of Fresh Surface Water Withdrawals from Water Management Areas or Reservoirs Withdrawals of fresh surface water from the aforementioned water management areas or proposed reservoirs would be subject to permitting by SJRWMD. For existing storage areas that are part of the Upper Basin project, water availability may be an issue if the safe yield of the existing storage areas has been met by agricultural uses. SJRWMD has indicated that presently a safe yield number for water supply from the Upper Basin project has not been determined. However, SJRWMD is getting closer to knowing how much water will be available for water supply. Operational guidelines for the Water Conservation Areas in the County will be a constraint on available supply, but the major constraints on water supply from the St. Johns River are the existing and proposed minimum flows and levels at the following locations: St. Johns River at Lake Washington; St. Johns River at Lake Poinsett; and St. Johns River at State Road N:\6706\IRC\WLB3130 Sec 5.doc

45 Section 5 Fresh Surface Water/Reservoirs The work to quantify the water available from the St. Johns River while meeting the minimum flow levels is underway at SJRWMD. If the C-25 canal and the Upper Basin project are reconnected and a reservoir established, a considerable amount of water would become available for use. Likewise, the new Fellsmere Water Management Area (WMA) would potentially have water available for water supply. The use of water from water management areas or reservoirs in western Indian River County would require pipelines and pumping stations to convey the water to the North County WTP. The length of the pipelines could be on the order of 23 miles based on pipeline routes shown in Figure 5-3. Pipelines would require obtaining easements and rights-of-ways, presuming they are along road rights-of-way. The treatment process anticipated for surface water is microfiltration/ultrafiltration followed by chlorination. If suspended solids are significant, an alternative treatment process is Actiflow followed by ozonation and filtration as in the case of Tampa Bay Water surface water treatment plant (described in more detail below). A preliminary recommendation is for raw water to be pumped to the coast and treated there rather than water treatment adjacent to the reservoir areas and having to maintain a chlorine residual in the treated water over the entire length of the pipeline. The permitting of treatment technologies for surface water would be fairly standard. 5.2 Pros and Cons of Using Fresh Surface Water Pros: The County has significant quantities of fresh surface water available for water supply. The O&M cost of treatment would be significantly less for surface water treatment than treatment of ground water or seawater using reverse osmosis. Application can be made to SJRWMD for the use of existing water storage areas. Cons: Treatment of surface water would require implementing an additional treatment technology completely different from existing RO treatment. The safe yields of the St. Johns River and the Upper Basin project have not yet been determined; this determination is expected in the near future. The timing of the availability of surface water from the proposed Fellsmere WMA has not yet been determined. 5-5 N:\6706\IRC\WLB3130 Sec 5.doc

46 STATE HWY 510 US 1 58TH AVE 9th ST SW 90TH AVE GOODWIN ROAD COUNTY HWY 507 STATE HWY 512 I95 STATE HWY 60 FLORIDA, USA Blue Cypress Marsh Conservation Area Fort Drum Marsh Conservation Area Fellsmere Water Management Area Blue Cypress Water Management Area - E North WTP South WTP St. Johns Water Management Area Blue Cypress Water Management Area - W Legend Conservation Area (CA) Water Management Area (WMA) South County WTP North County WTP County Boundary Potential Surface Water Reservoir Pipeline Cloud Grove (Potential Surface Water Resevoir) 0 10,000 20,000 40,000 Feet 1 inch equals 3 miles Figure 5-3 Indian River County Proposed Pipeline Routes

47 Section 5 Fresh Surface Water/Reservoirs SJRWMD and SFWMD are still discussing the reconnection of C-25 canal with the Upper St. Johns project and no timetable has been established for the development of additional storage in this area. Long pipelines involving significant costs would be necessary to convey fresh water to coastal water treatment plants and distribution systems. Currently these pipelines would go to the area of the North County Water Treatment Plant because of the lack of road rights-of-ways to the west of the South County Water Treatment Plant. 5.3 Cost Impacts As indicated above, the Tampa Bay Surface Water Treatment Plant is a 66-mgd, stateof-the-art, regional surface water treatment plant. The design was one component of a 15-year design/build/operate (DBO) contract awarded to USFilter for the project. Tampa Bay Water owns and financed the facility. Plant construction was completed in September 2002 on a tract of land located in an industrial area near Broadway and U.S. 301 in the Brandon area. The surface water treatment plant uses a high-rate ballasted flocculation/ sedimentation process consisting of a proprietary system provided by Veolia Water North America Kruger Products with the trade name ACTIFLO. This system replaces a traditional rapid mix coagulation, flocculation, and sedimentation process. This process is particularly advantageous when treating large flow rates with variable raw water quality, the conditions anticipated for the regional water treatment plant. The facility treats water from the Hillsborough and Alafia rivers and Tampa Bypass Canal to standards that exceed the current EPA Safe Drinking Water Act requirements for potable water. The ACTIFLO Process operates similarly to a conventional flocculation-sedimentation design, with the exception that 130 to 150 micron sand (microsand) is added to the water during the flocculation process in order to enhance both coagulation and settling. The microsand adds surface area in the coagulation process, which significantly improves the frequency of collision of dispersed or colloidal particles in the raw water with oppositely charged coagulated floc. This action accelerates the coagulation and flocculation processes. The ACTIFLO treatment process is immediately followed by ozonation and dual-media biologically active filtration. The new 66-mgd water treatment plant treats water at a rate of 40 cents per thousand gallons, significantly lower than earlier estimates, and guarantees higher water quality than originally specified. The summary of costs for the 66-mgd Tampa Bay surface water treatment plant is shown in Tables 5-1, 5-2, and 5-3. This is a significantly larger facility than what would be required to meet the County s needs, but it is presented as an example of a successful state-of-the-art facility. 5-7 N:\6706\IRC\WLB3130 Sec 5.doc

48 Table 5-1 Summary of Capital Cost Treatment Technology : Tampa Bay Water Surface Water Treatment Plant August 2006 Dollars Item Allowance Plant Capacity (mgd) No. Description Factor Raw water supply $8,950, Pretreatment $2,204, Process equipment $21,211, Post treatment $13,183, Intermediate storage (clearwell) $0 6. Transfer pumping $707, Finished water storage $0 8. High service pumping $2,877, Plant infrastructure $5,066, Concentrate disposal $9,825,000 Subtotal: $64,023, Yard piping $4,293, Electrical $4,213, Instrumentation and controls $0 14. Site work $2,571,000 Subtotal: $75,100, General Requirements $1,754, Contractor overhead and profit $14,611, Construction contingency $2,114,000 Opinion of Probable Construction Cost: $93,579, Technical Services $0 19. Owner administration and legal $0 20. Project contingency $0 Opinion of Probable Capital Cost: $93,579,000 Opinion of Equivalent Annual Capital Cost: $8,833,196 Plant service life = 20 years Annual interest rate = 7% Unit Probable Construction Cost ($/gpd) $1.42 Unit Probable Total Capital Cost ($/gpd) $1.42 N:\6706\IRC\WLB3097 Sec 5 Tables.xls

49 Table 5-2 Summary of Annual Operation and Maintenance Cost Treatment Technology : Tampa Bay Water Surface Water Treatment Plant August 2006 Dollars Assumptions Unit power cost = $ per kw-hr Item Plant Capacity (mgd) No. Description 66 Variable Costs 1. Power $1,008, Chemicals $3,132, Replacement parts and materials $675,000 a. Replacement membranes: Fixed 4. Operation and maintenance labor $4,159, Administration/regulatory compliance $707,000 Annual Production at Rated Capacity, (mgy) 24,090 Annual O&M Cost at Rated Capacity $9,681,000 Unit Cost at Rated Capacity, $/kgal $0.40 Annual Production at Avg Day Demand, (mgy) 15,586 Annual O&M Cost at ADD Capacity $7,981,000 Unit Cost at Rated Capacity, $/kgal $0.51 N:\6706\IRC\WLB3097 Sec 5 Tables.xls

50 Table 5-3 Summary of Total Production Cost Treatment Technology : Tampa Bay Water Surface Water Treatment Plant August 2006 Dollars Item Plant Capacity (mgd) No. Description 66 Production Costs at Rated Capacity 1. Equivalent annual capital cost $8,833, Annual O&M Cost - Variable $4,815, Annual O&M Cost - Fixed $4,866, Annual R&R fund deposit(1): $883,000 Total Annual Cost: $19,397,000 Annual Production at Rated Capacity, (mgy) 24,090 Annual Production Cost at Rated Cap. ($/kgal): $0.81 Production Costs at Average Day Demand (ADD) MDD/AADD factor(2): Equivalent annual capital cost $8,833, Annual O&M Cost - Variable $3,115, Annual O&M Cost - Fixed $4,866, Annual R&R fund deposit(1): $883,000 Total Annual Cost: $17,697,000 Annual finished water production rate (mgy)(3): 15,586 Annual Production Cost at ADD ($/kgal): $1.14 Notes: (1) Annual deposit to a renewal and replacement (R&R) fund is equal to 10% of the equivalent annual capital cost. (2) Maximum day demand (MDD, equal to the plant capacity rating) divided by the annual average daily demand (AADD). This factor is used to calculate the AADD to be used in the calculation of the annual production cost. (3) Annual finished water production rate in million gallons per year (mgy) is equal to the AADD (mgd) times 365 days. N:\6706\IRC\WLB3097 Sec 5 Tables.xls

51 Section 5 Fresh Surface Water/Reservoirs Microfiltration/ultrafiltration (MF/UF) can also be used as a treatment method for surface water. CDM has developed an opinion of probable costs for MF/UF WTP sizes in the range of 5 mgd to 20 mgd for surface water treatment. These are more in the range of what may be required by the County in the future, and these costs are shown in Tables 5-4, 5-5, and 5-6. Pipeline costs could be significant for conveyance of raw water from surface water reservoirs in the western part of the County. Based on the pipeline routes shown in Figure 5-2, CDM has estimated pipeline costs to each potential site, as shown in Table 5-7. Pipeline costs for a 20-inch ductile iron pipe capable of conveying 18 mgd over a distance of 23 miles could exceed $10 million using rights-of-way along existing roads. Pumping stations to maintain pressure are not factored into these costs. Cost estimates provided in this section assume that construction of a surface water treatment plant would occur at the existing North County WTP site, and does not include a land acquisition cost component. 5.4 Schedule of Implementation The time frame for land acquisition, permitting, design and construction of a new surface water treatment facility including pipelines is expected to be on the order of six to ten years from both authorization and confirmation by SJRWMD that water is available. In the case of the Fellsmere WMA, this storage area is not scheduled to be complete and ready for flooding by SJRWMD until The conceptual reservoir in the vicinity of the Cloud Grove development is more uncertain as to when it will exist. Withdrawal of surface water from western reservoirs will require a safe yield determination by SJRWMD that will ensure water availability during dry/drought periods. While not discussed in this analysis, an alternative source available during droughts may be necessary. The longer time frame may be more realistic because of the need to acquire more than 20 miles of road rights-of-way/easements and potentially more land for a surface water treatment plant site N:\6706\IRC\WLB3130 Sec 5.doc

52 Table 5-4 Opinion of Probable Capital Cost Treatment Technology : Microfiltration/Ultrafiltration August 2006 Dollars Item Allowance Plant Capacity (mgd) No. Description Factor Raw water supply $548,000 $922,000 $1,249,000 $1,550, Pretreatment $147,000 $248,000 $336,000 $416, Process equipment $2,079,000 $3,496,000 $4,738,000 $5,879, Post treatment $272,000 $458,000 $621,000 $770, Intermediate storage (clearwell) $754,000 $1,365,000 $1,850,000 $2,296, Transfer pumping $0 $0 $0 $0 7. Plant infrastructure $579,000 $1,050,000 $1,423,000 $1,766, Residuals disposal $284,000 $477,000 $647,000 $803,000 Subtotal: $4,663,000 $8,016,000 $10,864,000 $13,480, Yard piping 11% $513,000 $882,000 $1,195,000 $1,483, Electrical 18% $839,000 $1,443,000 $1,956,000 $2,426, Instrumentation and controls 11% $513,000 $882,000 $1,195,000 $1,483, Site work 11% $513,000 $882,000 $1,195,000 $1,483,000 Subtotal: $7,041,000 $12,105,000 $16,405,000 $20,355, General Requirements 9% $633,690 $1,089,450 $1,476,450 $1,831, Contractor overhead and profit 15% $1,056,150 $1,815,750 $2,460,750 $3,053, Construction contingency 15% $1,056,150 $1,815,750 $2,460,750 $3,053,250 Opinion of Probable Construction Cost:: $9,786,990 $16,825,950 $22,802,950 $28,293, Technical Services 25% $2,447,000 $4,206,000 $5,701,000 $7,073, Owner administration and legal 5% $489,000 $841,000 $1,140,000 $1,415, Project contingency 15% $1,468,000 $2,524,000 $3,420,000 $4,244,000 Opinion of Probable Capital Cost: $14,191,000 $24,397,000 $33,064,000 $41,025,000 Opinion of Equivalent Annual Capital Cost: $1,339,530 $2,302,904 $3,121,008 $3,872,470 Plant service life = 20 years Annual interest rate = 7% Unit Probable Construction Cost ($/gpd) $1.96 $1.68 $1.52 $1.41 Unit Probable Total Capital Cost ($/gpd) $2.84 $2.44 $2.20 $2.05 N:\6706\IRC\WLB3097 Sec 5 Tables 2.xls

53 Table 5-5 Opinion of Annual Operation and Maintenance Cost Treatment Technology : Microfiltration/Ultrafiltration August 2006 Dollars Assumptions Unit power cost = $0.10 per kw-hr Item Plant Capacity (mgd) No. Description Variable Costs 1. Power $140,000 $281,000 $421,000 $562, Chemicals $59,000 $119,000 $178,000 $237, Replacement parts and materials $230,000 $387,000 $525,000 $651,000 Replacement Membranes $32,000 $64,000 $97,000 $129,000 Fixed 4. Operation and maintenance labor $459,000 $565,000 $638,000 $695, Administration/regulatory compliance $312,000 $525,000 $712,000 $883,000 Annual Production at Rated Capacity, (mgy) 1,825 3,650 5,475 7,300 Annual O&M Cost at Rated Capacity $1,232,000 $1,941,000 $2,571,000 $3,157,000 Unit Cost at Rated Capacity, $/kgal $0.68 $0.53 $0.47 $0.43 Annual Production at Avg Day Demand, (mgy) 1,217 2,704 4,212 5,840 Annual O&M Cost at ADD Capacity $1,078,000 $1,720,000 $2,289,000 $2,841,000 Unit Cost at Rated Capacity, $/kgal $0.89 $0.64 $0.54 $0.49 N:\6706\IRC\WLB3097 Sec 5 Tables 2.xls

54 Table 5-6 Opinion of Total Production Cost Treatment Technology : Microfiltration/Ultrafiltration August 2006 Dollars Item Plant Capacity (mgd) No. Description Production Costs at Rated Capacity 1. Equivalent annual capital cost $1,340,000 $2,303,000 $3,121,000 $3,872, Annual O&M Cost - Variable $461,000 $851,000 $1,221,000 $1,579, Annual O&M Cost - Fixed $771,000 $1,090,000 $1,350,000 $1,578, Annual R&R fund deposit(1): $134,000 $230,000 $312,000 $387,000 Total Annual Cost: $2,706,000 $4,474,000 $6,004,000 $7,416,000 Annual Production at Rated Capacity, (mgy) 1,825 3,650 5,475 7,300 Annual Production Cost at Rated Cap. ($/kgal): $1.48 $1.23 $1.10 $1.02 Production Costs at Average Day Demand (ADD) MDD/AADD factor(2): Equivalent annual capital cost $1,340,000 $2,303,000 $3,121,000 $3,872, Annual O&M Cost - Variable $307,000 $630,000 $939,000 $1,263, Annual O&M Cost - Fixed $771,000 $1,090,000 $1,350,000 $1,578, Annual R&R fund deposit(1): $134,000 $230,000 $312,000 $387,000 Total Annual Cost: $2,552,000 $4,253,000 $5,722,000 $7,100,000 Annual finished water production rate (mgy)(3): 1,217 2,704 4,212 5,840 Annual Production Cost at ADD ($/kgal): $2.10 $1.57 $1.36 $1.22 Notes: (1) Annual deposit to a renewal and replacement (R&R) fund is equal to 10% of the equivalent annual capital cost. (2) Maximum day demand (MDD, equal to the plant capacity rating) divided by the annual average daily demand (AADD). This factor is used to calculate the AADD to be used in the calculation of the annual production cost. (3) Annual finished water production rate in million gallons per year (mgy) is equal to the AADD (mgd) times 365 days. N:\6706\IRC\WLB3097 Sec 5 Tables 2.xls

55 Table 5-7 Proposed Pipeline Cost from Various Surface Water Storage Areas to Indian River County North Water Treatment Plant No From Reservoir Total Pipline Length (Ft) Pipeline Length by Setting (Ft) Urban Suburb an Pipe Cost per LF($) For 30-inch DIP Cost of Installation ($) Rural Urban Suburban Rural Total Cost ($) = Installation + Cost of Pipe 1 Fellesmere WMA 101,376 5,808 24,816 70, ,000 2,020,000 2,880,000 17,060,000 2 St. Johns WMA 121,968 5,808 24,816 91, ,000 2,020,000 3,720,000 20,220,000 3 Blue Cypress Marsh CA 112,464 35,212 24,816 52, ,300,000 2,020,000 2,130,000 21,150,000 4 Blue Cypress WMA 97,152 5,808 24,816 66, ,000 2,020,000 2,710,000 16,410,000 5 Fort Drum Marsh CA 112,464 35,212 24,816 52, ,300,000 2,020,000 2,130,000 21,150,000 6 Cloud Grove 76,560 50,160 21,120 5, ,120,000 1,720, ,000 16,700,000 Notes: 1 WMA is Water Management Area; CA is Conservation Area. 2 It is assumed that the area east of 58th Avenue is urban, area between 58th Ave and 90th Ave is suburban and area west to 90th Ave is Rural. 3 Cost of 30-inch DIP installation per LF: Urban Suburban Rural $ $81.37 $ The following table show the flows from pipelines (20, 24 and 30 inch) meet demands greater than 2025 max daily demand i.e MGD Flow (MGD) Pipe diameter (inches) Area (sq. ft.) Flow* (ft 3 /sec) *A velocity water is assumed as 8 ft/sec. 5 All costs are rounded off to four significant figures. 6 All pipelines run from reservoir to North county WTP. 7 The safe yield of IRC reservoirs is not currently known. N:\6706\IRC\WLB3130 Table 5-7.xls

56 Section 6 Conclusions and Recommendations 6.1 Conclusions The purpose of this Alternative Water Supply Plan is to evaluate the potential raw water supply sources within the County that could serve as the future long-term water supply beyond the capacity of the current WTPs. The study examined the benefits and drawbacks of utilizing the surficial aquifer, seawater desalination, and surface water supplies in comparison to the current practice of pumping from the UFA. Table 6-1 summarizes the costs associated with each option, as well as the actual production cost data for the existing process (UFA aquifer/nanofiltration treatment at the two WTPs) budgeted for FY2007/2008. For comparison purposes, both the actual production costs for the current nanofiltration process (UFA aquifer) and the equivalent costs for building a new nanofiltration WTP with the associated wellfield are provided. Surficial aquifer WTPs are a viable option given a favorable set of circumstances. Shallow surficial wells typically have much lower production yields, thus requiring many more wells to produce the necessary volume of water compared to their UFA counterparts. In the case of the County, approximately 60 wells and well sites would be required. The primary obstacle for this option is acquiring the well sites, which often comes with a high real estate price tag and much opposition from neighboring property owners. Due to the anticipated land acquisition obstacles, it is anticipated that implementation of this option would require approximately six to eight years from the date of authorization. As shown in Table 6-1, the production costs for this process is less than the County s current costs. Although seawater desalination (an RO process) would undoubtedly provide the most volumetrically abundant raw water supply, it is by far the most costly process to construct, operate, and maintain. Additionally, there are logistical issues associated with siting a desalination facility. Desalination facilities are typically sited adjacent to existing power plants at which intake and disposal lines are already constructed, enabling the WTP to take advantage of existing infrastructure (assuming pipeline capacity is available and an agreement is reached with the utility owners). The costs provided in Section 4 for seawater desalination do not include the cost to construct an intake pipeline or a concentrate disposal pipeline. There are no existing power plants or intake/effluent pipelines within the County that can be utilized by a new desalination facility. The cost to construct the necessary pipelines to the ocean would further add to the cost of this option if surface seawater is the desired source. Permitting of a desalination facility is a complex process. The anticipated time frame for implementation of this option is six to ten years from the date of authorization. 6-1 N:\6706\IRC\WLB3130 Sec 6.doc

57 Section 6 Conclusions and Recommendations Table 6-1 Summary of Opinion of Probable Cost for Treatment Technologies Using Various Raw Water Sources Raw Water Source/ Treatment Method/ Plant Capacity (mgd) Raw Water Source Concentrate Disposal Capital Cost Annual O&M Cost Production Cost ($/1000 gallons) 4 Current Costs of UFA Using Low Pressure RO - Actual Costs (FY ) Surface Groundwater Water Discharge $1,551,882 $5,102,572 $2.05 Fresh Surface Water Using Microfiltration/Ultrafiltration 5 Surface Water N/A 2 $14,191,000 $1,078,000 $ Surface Water N/A 2 $24,397,000 $1,720,000 $ Surface Water N/A 2 $33,064,000 $2,289,000 $ Surface Water N/A 2 $41,025,000 $2,841,000 $1.22 Surficial Aquifer Using Nanofiltration 5 Groundwater Deep Injection Well $24,178,000 $1,646,000 $3.42 (DIW) 10 Groundwater DIW $33,576,000 $2,836,000 $ Groundwater DIW $41,573,000 $3,913,000 $ Groundwater DIW $50,188,000 $4,992,000 $1.75 Continued Use of UFA Using Low Pressure RO-New WTP and Wellfield 5 Groundwater DIW $34,693,000 $1,758,000 $ Groundwater DIW $48,579,000 $3,181,000 $ Groundwater DIW $64,086,000 $4,526,000 $ Groundwater DIW $79,077,000 $5,910,000 $2.42 Seawater RO Treatment Surface/ 3 DIW $39,429,000 $3,145,000 $5.95 Ground Water Surface/Ground 3 DIW $64,094,000 $6,230,000 $4.77 Water Surface/Ground 3 DIW $92,828,000 $9,248,000 $4.48 Water Surface/Ground 20 3 DIW $115,436,000 $12,432,000 $4.18 Water mgd is combined WTP capacity; actual average production for the FY is projected to be 8.89 mgd. Production cost based on actual average production estimate of 8.89 mgd (3,246 mgy) 2 MF/UF do not produce a concentrate steam as with nanofiltration and RO systems. Residuals need to be removed from the backwash water and chemicals in the backwash solution may require neutralization prior to disposal. 3 Costs include only treatment. Cost of an influent pipeline or deep well to the Boulder Zone as a source is not included. Deep Injection Well disposal would vary between $5.5 million and $11 million for the water treatment plant capacities presented. 4 Annual O&M and production costs are based on average daily demand using a maximum daily demand/annual average daily demand ratio. 6-2 N:\6706\IRC\WLB3130 Sec 6.doc

58 Section 6 Conclusions and Recommendations Although safe yield calculations have yet to be completed by SJRWMD for the various reservoir projects in the County, it is believed that a substantial volume of fresh surface water will be available for various uses upon completion of the reservoir projects. SJRWMD currently has six reservoir projects underway as part of the Upper Basin project in the County. Use of fresh surface water from any one of these reservoirs, or a combination thereof, would be subject to the SJRWMD permitting process. Exact completion dates for these projects are not currently available, but it is anticipated that permits will not be available until roughly The existing membrane treatment process at the County s WTPs is not readily adaptable to treat surface water, and therefore construction of a new treatment facility would be required. As shown in Table 6-1, production costs associated with construction, operation, and maintenance of a surface water WTP would be less than the current practice. 6.2 Recommendations The combination of the existing capacity at the North and South County WTPs, and the interim expansion of the North County WTP that is currently underway will provide a total combined finished water capacity of mgd. Based on the SJRWMD population and demand projections in Table 2-1, the existing WTPs and interim expansion of the North County facility will meet maximum day finished water demands through the year It is the County s desire to implement an alternative water supply and treatment process, to replace the current practice of treating UFA water via nanofiltration, to meet demands beyond As discussed above, the alternatives evaluated in this report will require between six and ten years for implementation. It is for this reason that the County Department of Utility Services is urgently seeking guidance from the BOCC to identify the alternative with which to proceed and to begin the implementation process in order to meet the 2017 target date. It is the opinion of CDM and the Department of Utility Services that pursuing fresh surficial aquifer withdrawals from the SJRWMD reservoir projects (and/or the Cloud Grove reservoir if it materializes) and construction of the associated surface water treatment facility is the most feasible alternative to continued use of the UFA. However, the uncertainty associated with the completion schedule of the reservoir projects raises concern with regards to the 2017 target date. The suggestion by SJRWMD (see Appendix A) to install all six new production wells now with lower pumping rates may help alleviate this concern in the future. If the six wells were installed as part of the current expansion and equipped with smaller pumps and motors to restrict withdrawals to the current requested allocation, then the pumps and motors could be changed out to larger ones in the future to bridge the gap between 2017 and the time when the alternative can be fully implemented. At that time, the UFA withdrawals would be reduced back to the previous limits and the alternative source would provide the balance of the demand. 6-3 N:\6706\IRC\WLB3130 Sec 6.doc

59 Section 6 Conclusions and Recommendations A public workshop is scheduled for June 21, 2007, to include the BOCC, County staff, CDM, and representatives from both SJRWMD and SFWMD. At this workshop, the findings of the Alternative Water Supply Plan will be presented and comments from the BOCC and the general public will be addressed. The goal of the workshop is for the BOCC to provide staff with the direction to proceed with the selected alternative (to be determined at the workshop). At that time, CDM will incorporate all applicable comments into the report (from both the County and public) and produce a final Alternative Water Supply Plan. The final Plan will also include an anticipated planning schedule for the selected alternative. 6-4 N:\6706\IRC\WLB3130 Sec 6.doc

60 References

61 References CDM, Water Supply Cost Estimation Study. Report to the South Florida Water Management District, West Palm Beach, FL. Submitted March Crain, L.J., Hughes, G.H., Snell, L.J Water Resources of Indian River County, Florida. Florida Bureau of Geology, Report of Investigations No. 80. Florida Conservancy & Development Group. LLC Cloud Grove Development of Regional Impact, Application for Development Approval, Book I. Green, Kirby Letter to the Honorable Gary Wheeler, Chairman of the Indian River County Board of County Commissioners. January 2, PBS&J Summary and Methodology, C-25 Basin and Upper St. Johns River Basin Reconnection, St. Lucie and Indian River Counties. Report prepared for SJRWMD and SFWMD. PBS&J, 482 Keller Road, Orlando. Schiner, G.R., C.P. Laughlin, and D.J. Toth Geohydrology of Indian River County, Florida. Water Resources Investigations Tallahassee, FL. U.S. Geological Survey. Toth, D.J. and Huang, C Investigation of Groundwater Resources in Central Indian River County, Florida. St. Johns River Water Management District Special Publication SJ98-SP19. Palatka, FL. R-1 N:\6706\IRC\WLB3097 Ref.doc

62 Appendix A Letter from Kirby Green, SJRWMD

63

64

65

66 Appendix B Summary and methodology, C-25 Basin and Upper St. Johns River Basin Reconnection, St. Lucie and Indian River Counties, January 26, 2006, Final Report Prepared for SJRWMD and SFWMD

67 Executive Summary This project initiates a process to evaluate the benefits and constraints of restoring hydraulic connection between basins along the C-25 canal bordering the SJRWMD and SFWMD. Hydraulic re-connection is a return toward restoring pre-development flows with the added benefits of increasing water supply and improving water quality. This report summarizes available data, identifies stakeholders, estimates freshwater available for storage, demonstrates reservoir sizing, examines differences in rainfall between Districts, and presents a methodology for further analysis. The study area is currently drained by an extensive network of canals and drainage ditches that discharge on the east coast to the Indian River Lagoon (IRL) estuarine system and to the north to the Upper St. Johns basins and Blue Cypress Water Management Areas (Figure ES-1). In concert with restoration, tandem goals are to capture freshwater currently lost and to increase flexibility in managing flows for flood control and consumptive use. In the final analysis, benefits and constraints that will be evaluated include, but are not limited to, - Water supply augmentation, - Reduction in groundwater pumping and protection from saline intrusion, - Improvement in soil and surficial aquifer salinity levels (currently elevated from pumping Upper Floridan Aquifer groundwater for agricultural irrigation), - Restoration of timing and volume of flows to estuarine environments, - Increased flexibility in source and timing of fresh water available for all uses in multiple basins, - Increased storage capacity and increased flexibility for directing flow to storage, - Water quality improvements (groundwater, surface water, and estuarine water quality), - Wetland augmentation, restoration, mitigation, and/or construction, - Restoration of flows necessary to maintain minimum flows and levels, maintain recession dynamics, and maintain variability within naturally occurring ranges, - Maintenance of current levels of flood protection, - Utilization of the lowest quality water to fulfill the needs of different water uses, and - Compatibility with local and regional water and land use plans. ES-1 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

68 Executive Summary Figure ES-1 Existing Drainage Network in the Study Area ES-2 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

69 Executive Summary The main discharge points within the study area are listed below. The S-50, Main, and South spillways were selected for this analysis because daily mean flow data are available for each over a reasonably long historic record (40 or more years). These three points discharge drainage from about half of the study area acreage. Table ES-1 Drainage Basin Area (Acres) Discharge Point or Spillway Drainage Basin(s) Approximate Drainage Area (Acres) Percent S-50 C ,000 C-25 East 6,000 40% Indian River Farms - South South Portions of 10E 17,000 6% Indian River Farms - Main Central Portions of 10E 22,000 8% FPFWCD Basin 1 26,000 9% SJWCD Portions of 6A Portions of 6C 78,000 29,000 37% Total 288, % Analysis of Daily Mean Flow Data at Discharge Structures This report presents estimates of the volume of water available based on daily mean flow and stage data at several discharge points within the study area. Logically, when the water reaches the point of discharge, all upstream basin functions (inflows, storages, withdrawals, and losses) are accounted for. Thus, the volume that reaches the discharge structure is the remaining fraction of freshwater available for redirection. As example, the S-50 spillway is the primary point of discharge from the C-25 canal. The C-25 canal drains freshwater from approximately 116,000 acres in Basins C-25 and C-25 East. The canal discharges through the S-50 spillway to the IRL. Daily mean flow and stage data for the S-50 Spillway are available for the period of record from December 1964 to September Similarly, daily mean flow discharge data are available for the Main and South spillway in the Indian River Farms Water Control District for longer periods of record (1949 to 2004 and 1950 to 2004, respectively). The use of data over several decades helps to account for hydrologic variability over time. Historic flows for these three points account for drainage over about half of the study area acreage. The flow data were imported to a spreadsheet for analysis. The daily data were summed and averaged monthly and annually. The volumes of water available at various pumping rates were calculated to demonstrate potential capture volumes and losses. The pumping calculations assumed constant rates of continuous pumping based on available water from daily mean flows. ES-3 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

70 Executive Summary The data from just these three discharge points (S-50, Main, and South spillways) indicates that millions of acre-feet of freshwater have been lost over the past 50 years from man-made ditches and channels. If the volume from all discharge structures in the basins were included in the analysis, the estimated losses (conversely, the estimated available water) would be higher. Total volumes calculated from 40 to 50 years of record indicate there is sufficient volume from just these three discharge points to justify further analysis of hydraulic re-connection. The total volume of water available from each of three of the five primary discharge points in the basins is summarized below with the total period of record shown in the first table (ES-1). The second table (ES-2) and chart summarizes total flows for the corresponding years where the three datasets overlap ( ). Table ES-1 Estimation of Available Freshwater per Spillway 3 of 5 Primary Discharge Points in the C-25 and Upper St. Johns Study Area Based on Daily Mean Flow Data at Each Spillway for 40 to 50 Years of Record C-25 Canal Indian River Farms S-50 Main South Years of Record Grand Total (acre-ft) 5,540,675 3,008,205 1,573,950 Median (acre-ft per year) 131,513 50,729 29,028 Minimum* (acre-ft per year) 33,524 19,141 10,256 Maximum (acre-ft per year) 243,780 96,637 47,139 Standard Deviation (acre-ft per year) 55,081 14,942 9,070 * Minimum volumes for S-50 and Main are conservative in that there were days of record missing in these years. As example, the following summarizes data that can be roughly estimated from this analysis. In excess of 10 million acre-feet of fresh water has been discharged off the coast over the past 50 years. The C-25 canal drains about 40% of the study area and 3 times the acreage of the Main and South spillways; S-50 has discharge volumes over 1.5 times the sum of the Main and South spillway volumes. Redirecting flows from multiple discharge points to a single or series of reservoirs may maximize capture volumes and flexibility in determining optimum pump and delivery schedules. ES-4 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

71 Executive Summary Table ES-2 Estimation of Available Freshwater Total 3 Spillways 3 of 5 Primary Discharge Points in the C-25 and Upper St. Johns Study Area Based on Daily Mean Flow Data at Each Spillway in Overlapping Years of Data Total S50 + Main + South Grand Total ( ) 8,731,379 Acre-feet over 40 years Median 204,661 Acre-feet per year Minimum 82,978 Acre-feet per year Maximum 364,541 Acre-feet per year Standard Deviation 72,309 Acre-feet per year Annual Discharge - 40-yr Record ( ) Total Annual Discharge in Acre-Feet/Year S-50 Main South Total Year In looking at the 40 years of overlapping data for the three discharge points, an estimated total of 200,000 acre-feet of water may be available per year (median value). In given years, this may range from a low of about 80,000 to peak flows of about 350,000 acrefeet per year for the 3 discharge points. From interviews and review of past reports, it appears more than 22,000 acres of suitable land may be available for purchase in the study area to accommodate one or more large reservoir storage areas. ES-5 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

72 Executive Summary It appears that the network of drainage ditches and canals necessary to connect these flows to storage areas already exists. More study is needed to determine what, if any, modifications might be required to accommodate the flows. As a note it is highly recommended that future analysis use a data time range consistent with CERP projects, currently this is the 41 year range from Jan 1, 1965 through December 31, This report uses the range from Jan 1, 1965 to December 31, 2004 because complete datasets for 2005 were not yet available for all of the discharge points. This should be updated in future analyses. Preliminary Method of Reservoir Sizing A spreadsheet analysis of cumulative flows was developed to simulate filling a reservoir over 40 years and to give a preliminary estimate of optimum size based on various pumping rates. This preliminary analysis was constructed as demonstration; it is not complete and will require further development prior to use of even preliminary results. For example, Figure ES-2 depicts a simulation, based on the historical data from the past 40 years, of a 30,000 acre 30-foot deep reservoir storing available water from the S-50 spillway pumped at a continuous rate of 1000 cfs. Based on the previous flow analysis from the 3 spillways, this is roughly 93% of the available freshwater. As noted, this simulation is not accurate but the order of magnitude estimates allows preliminary planning in terms of the size and placement of storage options. In reality, the storage areas might be filled progressively in cells and there may be a combination of storage and treatment options. ES-6 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

73 Executive Summary Max Surface Area ac Storage Depth 30 ft Side slope 4 :1 bank width 120 Assume: Length = 2 width b = 720 Bottom Width = ft Bottom Length = ft Bottom Area = ac Ratio to top area Total ac-ft Initial Volume % 0 Initial Volume Reservoir Volume vs Time ( ) Cumulative change in volume (ac-ft) Outflows ET ft/day Use 300 ac-ft/day Refer Reservoir Stage and ET chart for time dynamics Year Rain ft/day 48 inches/yr Seepage 20% percentage of Rainfall ac-ft/day Pumping Rate 1000 cfs Figure ES-2 S-50 Daily Discharge, Pumping Rate = 1000 cfs, Maximum Cumulative Volume = 985,925 ac-ft ES-7 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

74 Executive Summary Rainfall Distribution Between the SJRWMD and SFWMD in the Study Area Two long term rainfall monitoring points were selected to evaluate the variability of local rainfall and water availability across the SJRWMD-SFWMD boundary. The analysis includes three approaches to evaluating rainfall input conditions: - cumulative rainfall differences between stations over the period of record, looking in particular for systematic variability, - comparison of rainfall totals in several temporal quanta (total, annual, monthly, weekly) to observe patterns of difference, and comparison of these differences to variances determined for each quanta to detect statistically significant deviation, and - examination of the statistical properties of the data for differences; exploring variability in daily rainfall volume-frequency relationships. - Cumulative Delivery Although total rainfall over the entire period of record differ by about 1%, the pattern of delivery over that time deviates substantially from random variability (Figure ES-3) The peak difference in cumulative rainfall is over 10 feet (120 ) of rainfall, a total that would be expected to have significant consequences for local water supply variability. Figure ES-3. Cumulative rainfall difference between Vero Beach and Ft. Pierce Towers, 1969 to Quantized Rainfall Comparisons To compare the frequency of significant deviations from equal rainfall delivery, the rainfall data were divided by several quanta (month, week, year) and the time series of differences were plotted. The plots show that there are regular occurrences of significant deviation from the expected condition of equal rainfall delivery at both time scales. ES-8 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

75 Executive Summary The relatively large differences in total rainfall that are used as thresholds for each quanta, and the high frequency of exceedance further reinforce the conclusion that rainfall delivery can vary between areas with sufficient magnitude to warrant consideration of local water storage and transfer. Statistical Rainfall Delivery Properties The final analysis evaluates the implicit properties of the rainfall delivery systems at each location. Figure ES-4 below shows the relationship between rainfall event frequency and magnitude. As expected, the relationship is logarithmic (log[frequency] rainfall -1 ) and qualitatively similar between locations. We note that large events (>5 ) are statistically less likely at the Ft. Pierce location, but, given the relatively short period of record, this is assumed to be circumstantial. The slope and intercept values of fitted lines are not statistically significantly different (a = 0.05) suggesting that the intrinsic properties of the rainfall delivery between the locations are the same. Figure ES-4. Comparison of frequency-magnitude relationship for rainfall delivery between locations. Fitted lines (exponential curves) are shown; parameter values for the fitted lines are not statistically different based on predicted standard error estimates. In summary, this is a preliminary analysis and further work could document variability between additional stations over longer time to deduce if these data are anomalous. However, based on these observations, it appears that there is significant variability in rainfall delivery between locations over a time scale that warrants further study of storage and delivery alternatives providing local shared access between Districts to attenuate water allocation constraints. ES-9 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

76 Executive Summary Methodology for Conceptual Design through Final Plans A general approach for further study is outlined in this report and is listed below although presented as a chain of events, it is an adaptive process with successive steps potentially feeding back to and refining prior steps (Figure ES-5). Summary Conceptual Model and Alternative Formulation Dynamic Systems Model and Preliminary Scenario Analysis Hydraulic and Hydrologic Model Geotechnical Studies Feasibility Studies Basis of Design Report Preliminary Design Through Final Plans and Specifications There are a number of previous reports and modeling efforts for basins in this study area. However, each was prepared for only a portion of the study area and each had different goals and objectives. The analysis in this report directly uses available historic discharge data. These data indicate that in excess of 10 million acre-feet of fresh water has been discharged off the coast over the past 50 years and, further, a median value of about 200,000 acre-feet of water will continue to be discharged each year. The mitigation of this loss and the potential benefits of restoring natural flows warrants further study in this area. A next step in the recommended methodology is to summarize demands and critical interactions. Together these data form the basis for preliminary scenario analysis. Statistical review of historical data indicate that there are local, short-term, differences in rainfall between the two Districts. These differences are sufficient to warrant restoration of cross-boundary flows in the form of shared storage and flexible distribution systems. Land use in the region is projected to rapidly shift to urban and residential coverage. This joint storage can serve as a flexible future source of drinking water for both Districts and a buffer for use by either District in times of local drought, fire, or unexpected need or offering additional diversion and capacity in times of excess water. This preliminary analysis indicates that the volume of freshwater currently lost, the projected future growth of this region, the on-going impacts to the IRL, and the variability in local rainfall in the area, all provide justification for the continued study and evaluation of this project.. ES-10 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

77 Figure ES-5 Systems Diagram of Conceptual Study Area Executive Summary ES-11 Summary and Methodology Water Budget Analysis C-25 and Upper St. Johns River Reconnection

78