DEVELOPMENT OF A WATER SUPPLY PLAN FOR POLK COUNTY & ITS MUNICIPALITIES

Transcription

1 DEVELOPMENT OF A WATER SUPPLY PLAN FOR POLK COUNTY & ITS MUNICIPALITIES Gary ReVoir II, P.E., Marc Cannata, P.E., Brandon Bryant, Devan Henderson, E.I., Gary Fries, P.E., Robert Beltran, P.E., BCEE, Audrie Goodwin, E.I., Brian Armstrong, P.G. & Chris Sweazy, P.G. The Florida Legislature has found areas in which existing sources of water are not adequate to supply water for all existing and future reasonable-beneficial uses and to sustain the water resources and related natural systems ( (1), F.S.). For these areas, the Water Management Districts (WMD) are required to publish regional water supply plans. Additionally, the WMDs have established designated areas of concern that include Polk County; the Southern Water Use Caution Area (SWUCA) and the Central Florida Coordination Area (CFCA). The CFCA encompasses all of Polk County, and the SWUCA region overlaps to include most of the County as shown in Figure 1. The concepts for the SWUCA and CFCA are as follows, and for those areas of overlap SWUCA regulations will be observed. Figure 1: Water Management District Areas in Polk County Southern Water Use Caution Area (SWUCA) Limits groundwater withdrawals revise Minimize saltwater intrusion to the aquifer Minimize impacts to the upper Peace River and Polk County lake levels Implement projects that restore minimum flows and levels (MFL) SWUCA supersedes CFCA

2 Central Florida Coordination Area (CFCA) Limits new groundwater allocations to 2013 demands Provides opportunity for longer permit duration to those utilities who commit to alternative water supply (AWS) projects Polk County has many challenges in the aspect of water supply. As an interior county, it lacks the advantage of access to a large water body supply for desalination. Any projects of this nature will involve long, complex treatment and distribution systems. For surface water considerations, two rivers have their headwaters in Polk County. Other issues Polk County is confronted with involving water supplies include large tracts of undeveloped land, the piezometric head of the state, lands and water bodies disturbed by historical mining uses, and 17 municipalities to coordinate interior regional approaches. It is anticipated that public water demands in Polk County may increase significantly in the next 20 to 30 years, and permittability of Upper Floridan water will depend on which part of the County the well is or will be located. Since traditional groundwater (Upper Floridan Aquifer) is Polk County s most widely used source for public supply water, the evaluation, development and implementation of alternative water supplies will need to occur in the near-term in order to meet long term demands. Preliminary Categories of Options As such, the intent of the study was developed to investigate options to meet the future water supply demands within the constraints of the regulations. The water supply planning effort began with the identification, quantification and confirmation of numerous types of new water supply which could be viably developed, and then aligned with a host of prospective water supply partners. A cooperative effort with Polk County, the local governments, the SWFWMD, SFWMD, and the Reiss Engineering Project Team developed throughout the course of the study. Although the plan was initially formed based on municipal supply, it became apparent that outreach with other large users is an integral part in planning for public supply. Through this investigation a listing of immediate projects and strategies have been identified which will materially provide a method to pursue new water supplies for all public utilities within Polk County. The study has also identified public utilities whose only recourse after maximizing conservation and reclaimed water may be the continued use of traditional groundwater sources, potentially relying on the transition of non public supply wells no longer in use to public supply to meet the local governments demands. As an interior County, the current traditional water supply from the Upper Floridan Aquifer (UFA), as well as all interior nontraditional supplies all have ultimate capacity limitations. Therefore, at some point in the future, the County and its local governments will have to consider additional water supply from outside of the County limits. The categories were selected for inclusion in the study based on their capability to provide a reliable increase in water supply, or to reduce the existing or future demand for water, thus extending the use of existing supplies. The following categories were the result of the initial list of options to be further investigated:

3 Surface Water o Rivers o Lakes o Stormwater Groundwater o Surficial Aquifer o Lower Floridan Aquifer (LFA) o Upper Floridan Aquifer (UFA) o Land Use Transitions Reclaimed Water o Residential/Commercial Irrigation o Large Scale Irrigation o Bulk Transfer to Large Industrial Users Other Water Supply/Partnerships o Tampa Bay Water (TBW) o St. Cloud, Toho Water Authority, Orange County, Polk County Utilities and Reedy Creek Improvement District (STOPR) o Peace RiverManasota Regional Water Supply Authority (PRMRWSA) Conservation o Indoor Residential/Commercial o Outdoor Residential/Commercial o Industrial/Commercial/Institution al (ICI) Investigation of Preliminary Options A planning level evaluation of the various water supply options identified during the previous analysis was performed, including: General literature research Location of sources Potential Yield Permittability Additional Benefit Cost Estimations Time to Implement Conclusion to Investigation Long List of Options Following the preliminary identification and investigation of alternative water supply options, a detailed, comprehensive listing of potential water supply projects was developed. The project team also investigated the current and future plans for each of the individual local governments in order to ensure that the overall project list included specific individual efforts currently planned. The list of options was compiled through discussion with Polk County, local governments, and the Water Management Districts through monthly meetings and conference calls which produced important feedback and participation. These projects were evaluated and updated over the course of this study as new and additional information became available. This information includes input from the Farm Bureau, the mining industry, and individual agricultural users. Development of Evaluation Criteria Matrix Due to the large number of projects on the Long List and the goals of the overall study to formulate a menu of options and provide an example plan on how Polk County and its local governments can meet future water demands, a method was developed to narrow down the list. The Evaluation Criteria Matrix (Matrix) was developed as a tool to be used to rank the projects in a quick, but technically sound manner, but is not intended to be a stand alone method for ranking or prioritizing projects. The Matrix was a method to quantify both qualitative and quantitative characteristics of each project in such a manner that they can be easily compared to one another. The intent of the matrix was developed as a tool to aid in engineering analysis and

4 judgment of the available options. Development of the matrix was a joint effort between the REI project team, the County, local governments and the Water Management Districts. It is based on the calculation of assigned percentages and scores for each issue discussed in the section above: yield, permittability, additional benefit, preliminary cost estimates, and implementation time. Although this is a screening level evaluation, it was essential to convey the importance of some components as compared to others. For example, one of the overall goals of this project is to identify available, alternative water supply and therefore yield was given a higher weighting value. Next, a weighting factor or percentage that each component contributes the overall score was allocated. The percentages were divided up among five components, with the total equaling 100%. This step was especially critical because it would ultimately determine projects that would likely provide the most benefit for supply. Communication between the REI project team, the County, local governments and the Water Management Districts lead to the selected percentages. The resulting Matrix score sheet is shown in Table 2 on the following page.

5 Table 1: Evaluation Criteria Matrix Description Grade Weight Max Grade* Total Allowable Score Yield (MGD) 30% Permittability 25% Very Difficult 0 Possible 5 Likely 7 No Issues 10 Additional Benefit 10% None 0 Some Additional Benefit 5 Benefits More Than One Party 10 Cost Index ($) 25% $ $ $ Implementation Time 10% Over 15 yrs 0 15 yrs 1 10 yrs 5 Less than 5 yrs 10 Total 100% 1000 Yield: The quantity of water available for treatment or quantity of water potentially available to reduce demands. Permittability: Potential of permitting the project within the current rules and regulations. Additional Benefit: Additional benefit will be referred to as multi-jurisdictional Cost Index: Considers the construction and long-term annual operating costs. Implementation Time: Time in which it would potentially take for the quantities to take effect. *Each project will be ranked from 0-10 in each category. A grade anywhere between 0-10 can be given for each project. A low grade will yield a low score and a high grade will yield a high score.

6 This multi-criteria decision analysis was applied to the Long List in order to assign a score to each project. Once the projects were scored, they were rearranged to go from the top ranking projects to the lower ranked projects. Short List of Options Based on the rankings as presented in the matrix, as well as engineering analysis and judgment, the projects considered the most technically viable and beneficial from the long list, as determined using the Matrix, were selected to form a Short List of projects for more detailed investigations. To select the projects to proceed forward with for further evaluation and to provide flexibility in the ultimate plan, the quantities from the top ranked projects of the long list were added cumulatively until the resulting supply quantity was 2 to 3 times the projected future demands. The approach provided, ensures an adequate flexibility in the event that some projects are found during later work to not be feasible or difficult to implement in the near-future for various reasons (i.e. schedule, cost, permitting, etc.). The resulting Short list is shown in the Table below. Table 2 The Short List of Options # Project Quantity (MGD) 1 Land Use Transitions Conservation SE Polk County Well Field Lakeland/PCU-TECO Hwy 60 Industrial Reuse City of Lakeland: C.W. Combee W.T.P. Groundwater Blending Polk County Utilities NERUSA: Lower Floridan Aquifer City of Lakeland: T.B. Williams W.T.P. Groundwater Blending City of Winter Haven: Fairfax W.T.P. Groundwater Blending City of Bartow: W.T.P. #10 Groundwater Blending City of Auburndale: Atlantic W.T.P. Groundwater Blending Peace River/ Land Use Transition Conjunctive Use Project Toho / STPOR Joint Bulk Water Supply Project City of Winter Haven: Reuse Option #3 - Calpine Energy Public Access Reuse Tampa Bay Water: Bulk Water Supply Project TOTAL 93.92* *This sum takes into account the fact that some of these projects may overlap. For example, project #11 is a part of project #1 **Green text indicates a category and not a specific project Demand Deficits The next steps of the evaluation included collection of each local government s public water supplies and needs, existing infrastructure, municipal water demands, future water demands, and supply deficit within the 2030 planning period. Existing water and wastewater sources were documented using information provided by Polk County and the 17 local governments, documents supplied by the Southwest Florida Water Management District (SWFWMD), South Florida Water Management District (SFWMD), and the Florida Department of Environmental

7 Protection (FDEP). In addition, the Reiss Engineering project team has maintained a close relationship and has met with many of the local governments to discuss current and future water supply needs. Future water demands are based mainly on population (growth) projections and historical use. Many of the local governments in Polk County, as well as throughout Florida had a significant rise in growth over the past 8 years beyond what was originally planned for in the late 1900s. However, growth rates have recently decreased from the middle of 2007 and continue to decrease in 2008 throughout the Central Florida area and the nation, due to the significant economic slowdown that is reflected perhaps most severely in the housing market sector. This downturn in growth, has directly affected original population projections and capital improvement projects planned for water supply. As such, it is of great benefit and importance to the local governments to work closely with SWFWMD and SFWMD to update population estimates, that will serve as additional water supply quantities needed to support growth. This Polk County Comprehensive Water Supply Plan includes the Water Management Districts water supply surplus and deficit estimates with input from the municipalities. The future demand values provided by the Water Management District will be used as the basis of this report. The potential demand deficits using SWFWMD projections are depicted in Figure 2. The presentation of the demand values ensures that each local government will have substantial projects to meet future water supply needs, with the flexibility to meet changing trends in growth. One of the primary goals of this water supply plan is to identify potential water supply opportunities for each of the local governments to implement in order to meet future water supply deficits, not to estimate a local government s future population. The projected population, current water demands, and supply deficits for the planning period through the year 2030 were found for the local governments and six PCU service areas. However, since the plan provides such a tremendous amount of flexibility in supply options in for each community, it is foreseeable that the plan could meet demands beyond the planning horizon of this study.

8 Figure 2: Polk County 2030 Water Deficit Project Implementation Requirements The next step for the water supply plan included a preliminary investigation of treatment options, distribution (transmission and storage) requirements, and environmental impact considerations. The conceptual level evaluation included both potable and reclaimed augmentation options. It was conducted for the preliminary categories of surface water, groundwater, reclaimed water, and other alternative supplies. Conservation measures were evaluated differently because conservation is an optimization of current supplies and therefore doesn t require treatment or transmission. The list of alternative water supply projects were compared to the current water supply deficit and analysis for the 17 local governments and 6 county service areas as a means to initiate the formation of an implementation plan to be able to meet future public water supply demands. Once the finished water quality goals and primary treatment criteria were determined, the treatment options to meet the required goals of the service areas of Polk County were investigated. This investigation of these alternatives included a planning level determination of:

9 Water quality and primary treatment criteria (PTC) Water treatment processes o Treatment trains o Disinfection alternatives o Post-stabilization alternatives Residual management considerations Finished water blending considerations Storage Considerations o Above ground o Below ground o Reservoir needs and location Environmental impact considerations Transmission options o Pumping considerations Cost Estimates Implementation Plan The investigations of this study resulted in the formation of an implementation plan that encompasses the 17 local governments and the 6 County service areas. Although a short list of the greatest source quantities was developed over the course of the study, it was only used as a guideline, and not the basis, for the project recommendations. A summary of the specific action items for consideration by Polk County and the local governments to implement annually throughout the planning period was documented. The final report includes the appropriate technical, economic, regulatory, and environmental characteristics In addition, a joint effort conservation analysis was performed. The purpose of the conservation analysis was to identify potential quantifiable impacts on potable water consumption for various water conservation methods if applied in Polk County. The conservation measures were evaluated for public (residential, industrial and commercial, recreation/aesthetic, and mining/dewatering) water supply sectors only. Potential conservation measures that may be applicable in County areas were evaluated for individual water savings potential and cost effectiveness. The majority of the conservation measures included are voluntary measures. From this evaluation specific conservation measures for each utility service area were selected for further analysis. A conservation protocol has been made to address conservation projects suitable for utilities. The protocol establishes a methodology for calculating cost effectiveness and water savings for utilities. These conservation plans were incorporated in the overall implementation plan to provide Polk County and the local governments with water supply options, along with implementation considerations, to satisfy demands throughout the planning period and possibly further in the future. As Polk County moves into the future its success in implementation of water supplies will greatly depend on forming key strategic partnerships with its 17 municipalities, large industrial users, mining industries, housing industries, and other key agencies outside of Polk County.