Fort Walton Beach Council agenda — 05-25-2010 Regular — reading text

indirect hydrologic impacts and subsequent water quality impacts. The objective of this project is to reduce the impacts of nonpoint source pollution from a heavily developed watershed in the Choctawhatchee Bay system that has historic water quality problems that have been documented in numerous reports. The alternatives proposed in this project will provide significant reductions of pollutant loading from the Gap Creek watershed and also provide attenuation and flood relief for residents and business owners in the watershed. If awarded, the grant funding for this project will help leverage the funds generated by the creation of the City's Stormwater Utility to implement a stormwater retrofit project that otherwise may not be completed for many years due to the City' s additional funding constraints during this economic downturn. The project is intended to accomplish the following objectives: 1. Provide stormwater treatment for 78 industrial acres of drainage area within the Gap Creek Basin that directly impacts the water quality of Cinco Bayou and Choctawhatchee Bay. 2. Reduce the nonpoint source pollutant loading of nutrients, suspended solids, heavy metals, and other urban non -point source pollutants into the Choctawhatchee Bay system. Restore and protect the natural biological communities, recreational and aesthetic qualities of this diverse resource for future generations. 3. Provide additional storage and attenuation of stormwater to help reduce non -point source pollution in an industrial area that has a potential for significant pollutant loading related this type of land use activities in the watershed. Attenuation of flow will also provide flood relief for downstream areas near Gap Creek. 4. Increase public awareness of the value of area water resources, the importance of preventing non -point source pollution, and best management practices for pollution prevention. PROJECT DESCRIPTION: The vast majority of the sub drainage basin contributing flow to this BMP is built out Industrial property. The proposed stormwater retrofit pollution reduction project will consist of an industrial community pollution education outreach program and a treatment train including the following components: Wet Detention An in line extended wet detention pond will allow for flood attenuation and provide effective treatment of flows through algal uptake and settling. The pond will be designed in such a of settled pollutant manner as to provide a forebay for pretreatment and prevention resuspension. The design will include the use of elevation changes within the pond to prevent 13-  short circuiting. The outlet structure will encompass a skimmer to prevent oil, grease and floating debris from being carried downstream. 2. Public Outreach and Education CBA is a local community based organization dedicated to protecting the Choctawhatchee Bay system. They provide public education about environmental stewardship and organize public involvement related to trash clean up events and restoration projects on and around the bay. CBA often partners with the City to help publicize the City' s projects and other programs directed at reducing nonpoint source pollution to the bay and other conservation measures to reduce pollution and protect natural resources. CBA will be a partner on this project to increase public awareness of the value of area water resources, the importance of preventing non -point source pollution, and best management practices for pollution prevention. They will provide public outreach specific to the Industrial community and educational press releases about the project. A " volunteer event( s)" will be coordinated by CBA during the project for volunteers to participate with helping plant native vegetation in the littoral zones of the facilty and /or provide trash cleanup around the project site and in the watershed. As the construction of the facility nears completion, the City and CBA will partner to provide a Lunch and Learn" type program for the industries located in the 78 acre contributing area. This program will be developed to inform the industries of the purpose for the construction project, provide information about the Gap Creek Watershed and the path that contributing runoff takes once it leaves their facility, and provide information regarding efforts each industry can take to enact water quality improvements at their respective facility. 14- ESTIMATED POLLUTANT LOAD REDUCTION: Other 4ther BMPs Installed Nix x TSS kglyr" z r Pond Pre -Project 375, 000 3, 000 23, 650 81, 800 a Post -Project 300, 000 2, 680 22, 600 68, 000 Load 75, 000 320 1, 050 13, 800 2 Reduction 0 a 4% 17% Reduction 20% 11% Other Other T5S TP TN Sediment BOD k r k/ r kgtyr kgfyr, kgty kglyr kg /yr N Pre -Project a Post -Project Load Reduction 6 Reduction Qth.e her TSS TP TN 5ed ment BdD kg /yr kglyr kg y/ r kglyr ' inn Pre -Project ea Post -Project Load Reduction 0 Reduction Other Other TSS TP' N Sed>ment BOQ k 1. kart r TOTAL kg(yr IIYr kglyr kglYrg yr Pre -Project 5 Post -Project Load 2 Reduction 0 a Reduction MODELMODEL USED:USED: TheThe pollutantpollutant loadload reduction reduction waswas estimatedestimated usingusing thethe Spreadsheet Spreadsheet ToolTool forfor thethe EstimationEstimation ofof ( ( STEPL),STEPL), Pollutant Pollutant LoadLoad versionversion 4.4. 1.1. TheThe estimated estimated combinedcombined BMPBMP efficiencyefficiency forfor thethe treatmenttreatment train,train,includingincluding thethe proposedproposed sandsand filter,filter, thethe meandering meandering vegetatedvegetated swale,swale, andand thethe proposedproposed detentiondetention pond,pond, waswas calculatedcalculated usingusing thethe BMPBMP CalculatorCalculator includedincluded inin STEPLSTEPL 4.4. 11 andand thenthen enteredentered intointo thethe STEPLSTEPL spreadsheet spreadsheet calculator.calculator. LANDLAND OWNERSHIP OWNERSHIP STATUS:STATUS: 15-15- The property required for the construction of the vegetated swale and the wet detention pond are located adjacent to a City Right of Way and is owned by Project Partner DRS. DRS has agreed to provide the City with a long term easement. TASK NARRATIVE: Task 1: Construction Plans and Permitting Permitting and construction plans will be developed for the proposed improvements. Plans will meet NPDES, ERP and local permitting requirements and will include plans for wetland plantings. Task 2: Construction After permits have been received, the projects will be bid and construction of the treatment train will be completed. Inspections by City personnel and the Northwest Florida Water Management District will insure that the improvements are built according to plans and specifications and meet permit and grant requirements. Task 3: Public Education CBA and the City will organize a " Lunch and Learn" type program for the industries located in the 78 acre contributing area. This program will be developed to inform the industries of the purpose for the construction project, provide information about the Gap Creek Watershed and the path that contributing runoff takes once it leaves their facility, and provide information regarding efforts each industry can take to enact water quality improvements at their respective facility. Educational signage will be provided to inform the public about the water quality aspects of wetlands, the value of area water resources, the importance of preventing non -point source pollution, and best management practices for stormwater treatment. Task 4: Monitoring A detailed monitoring plan will be developed and submitted for review after grant award. Base flow and storm event monitoring upstream and downstream of the proposed BMPs will be implemented to demonstrate the effectiveness of these practices at reducing pollutant loads and protecting the downstream water bodies. Task 5: Grant Administration and Reporting This task will include submittal of quarterly and annual reports on project activities. The City will be the lead entity responsible for drafting and submitting the reports. The NWFWMD will provide input and review for all reporting. All reports will be delivered to the FDEP project manager for the 319 grant program. A draft report will be delivered to FDEP for the project describing the construction phase, post - construction monitoring activities and evaluation of the effectiveness of the BMPs. The pollutant efficiency removal measured by the post construction monitoring will be evaluated to determine the effectiveness of the BMPs and qualitative and quantitative water quality impacts to the receiving water bodies including Gap Creek, Cinco Bayou and Choctawhatchee Bay. After review and comment by FDEP, a final project report will be provided. A Quality Assurance Project Plan QAPP) will be submitted and monitoring results will be uploaded to the EPA STORET database or the