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Yousef ( 1993 ) it is assumed that 25 % of the total nitrogen is associated with suspended material, and 40% of the total phosphorous is associated with the suspended material . The following table presents the results of efficiency calculations using these assumptions . Pre-Treatment Pond Estimated Removal Efficiencies Flow Rate TSS removal TN removal TP removal 10.0 MGD 62% 15 % 25 % The second BMP in the treatment train is a managed aquatic plant system (MAPS) . This is a proven technology currently being used in Okeechobee for a South Florida Water Management District ( SFWMD) project (Okeechobee S- 154 Managed Aquatic Plants System Water Treatment Facility) . That project, designed and operated by HydroMentia, Inc . , employs a MAPS that is a combination Water Hyacinth Scrubber (WHSTM) and algal turf scrubber system (ATSTM) . Recent testing of this system shows that water with nutrient concentrations similar to those in the IRFWCD can be treated to a high level just using an ATSTM without using a WHSTM . Based on the SFWMD ' s system' s performance, a six-acre ATSTM is capable of treating 10 MGD . The ATS contributes significantly to the overall continuous treatment efficiency of the treatment-train system. Results from the SFWMD project are incorporated into the estimated ATSTM removal efficiencies below: Algal Turf Scrubber ATS System Estimated Removal Efficiencies Flow Rate TSS Removal TN Removal TP Removal 10 MGD 80% 75 % 63 % The third BMP is a polishing pond. The polishing pond will offer some water quality improvements, but they are small compared to the high quality of treatment provided by the ATSTM . However, the polishing pond will provide an important ecological benefit and storage for water potentially needed by other users . It also allows any algal material that escapes from the ATSTM to be collected before final discharge. Finally, a small demonstration passive wetland polishing system will be provided. This tertiary treatment system will receive part of the treated flow discharging from the polishing pond. Through plant uptake and settling, the wetland polishing system will remove suspended solids and much of the dissolved nutrients that escape the polishing pond. The wetlands will be a valuable ecological enhancement and an important educational component and they will demonstrate that high quality wetlands may be established when they are properly loaded from a nutrient perspective . These wetlands will provide a needed habitat and refuge for the birds, amphibians, insects, and animals that the park will attract. They will become a valuable wildlife refuge and nature facility, demonstrating a successful effort to recreate this area ' s original ecosystem. Using the treatment efficiencies presented for each element of the treatment train (excluding the polishing wetland since it will not treat the entire design flow), the combined overall treatment efficiency of the system can be estimated: Overall Pollutant Removal Efficiencies for Egret Marsh Flow Rate TSS Removal TN Removal TP Removal 10 MGD 92% 78 % 72 % Resulting Annual Loads of Pollutants Removed lbs. er ear INNEMENEW 448 ,091 1 37 ,753 11 ,397 The significance of these removal rates are realized when they are compared with the total loadings from the IRFWCD ' s 50,000+ acre basin and the basin ' s proposed load reduction goals : The Treatment System' s Removal Efficiencies Compared With IRFWCD ' s Total Loadings and the Corresponding Load Reduction Goals Established by the Master Plan Description Percent TSS Percent TN Percent TP Removed Removed Removed IRFWCD Basin ' s total loading 1 ) 7 % 10% 17% Proposed Load Reduction Goal 2 ) 12 % 20% 35 % ( 1 ) The total yearly loadings from the IRFWCD are : TSS = 6, 167 ,733 pounds/year, TN = 385 , 596 pounds/year, and TP = 66,380 pounds/year. [ 1995 draft SWIM program as listed on page 86 of the Master Plan. ] DEP Agreement No. G0143 , Attachment A, Page 3 of 9