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(2) The load reduction goals for the IRFWCD basin are : TSS = 3 , 597, 783 pounds/year, TN = 190, 280 pounds/year, and TP = 32 ,971 pounds/year. [Page 87 of the Master Plan. ] As the above table shows, Egret Marsh ' s treatment system will meet 35 percent of the total phosphorus load reduction goal for the IRFWCD and 20 percent of the IRFWCD ' s total nitrogen load reduction goal. These results indicate a very significant step toward achieving the pollution reduction targets established by the Master Plan. Just as noteworthy, the ATSTm has been shown by the SFWMD studies to facilitate some reduction of color from the tannin stained canal water. This is a very important benefit because clearer water will result in better light penetration through the water column, and this will aid in the recovery and growth of seagrass in the IRL . Use of EPA STEPL Model to Estimate Pollutant Load The Spreadsheet Tool for the Estimation of Pollutant Load (STEPL) was applied to the 9, 000-acre basin. Estimates for TSS loading using the model are slightly higher than the water quality based estimates, 798 tons/year versus 609 tons/year. Estimates for TP loadings using water quality data were five times higher than the model estimate and water quality based estimates for TN loadings were three times higher than the model estimates . We believe the water quality based estimates are more accurate for pollutant load reduction calculations for this proj ect. PROJECT OBJECTIVES : The objectives of this project are as follows : 1 . Reduce high levels of nitrogen, phosphorous, suspended solids, and other loads from an agricultural basin to the Indian River Lagoon in the vicinity of Vero Beach, Florida. 2 . Provide Indian River County staff with a full-scale facility operating experience, as they consider managed aquatic plant systems for meeting the interim goal of 50% pollutant load reduction. 3 . Demonstrate the Algal Turf Scrubber® technology as an effective structural BMP to citrus growers in the Indian River Farms Water Control District and the public . 4 . Assess the use of an Algal Turf Scrubber® to treat the variable flows from a water control district, significantly reducing the land space needs in a basin that is rapidly changing to urban use with escalating land values . 5 . Assess the use of a managed aquatic plant system to reduce seagrass growth-inhibiting optical parameters, including suspended solids, turbidity, and color, 6 . Evaluate the use of a recycle stream in the Algal Turf Scrubber® to achieve enhanced removals from the aquatic plant system, 7 . Identify beneficial uses for the biomass produced, to include but not be limited to soil additive, animal feed materials, and biogas production, and 8 . Educate the public about the potential for pollutant load reduction to the IRL using managed aquatic plant systems for stormwater treatment. PROJECT DESCRIPTION : The Indian River Farms Water Control District (IRFWCD) is a Florida Statutes Section 298 drainage district that encompasses approximately 50, 000 acres in Indian River County. About 35 % of the IRFWCD area is agricultural, primarily citrus . Over 50% of the area, however, is urban, and the urban land use is increasing steadily. Three primary canals discharge stormwater runoff and groundwater into the Indian River Lagoon, with flows regulated to some extent for both drainage and irrigation purposes through several control structures (IRLNEP(b), 1994) . Secondary and tertiary ditches flow into the primary canals, most of which were constructed beginning in the 1920 ' s . According to the Indian River Lagoon Comprehensive Conservation and Management Plan (IRLNEP(a), 1996), the IRFWCD is one of several large inter-basin drainage systems that extended the historic drainage basin of the Indian River Lagoon into large areas that previously drained into the St. Johns River. As a result of this drainage DEP Agreement No. G0143 , Attachment A, Page 4 of 9