FDEP \ STORMWATER TREATMENT REPORT SECTION 1 INTRODUCTION The discharge of stormwater within the State of Florida has been subject to regulation since the early 1980s to prevent pollution of Waters of the State and to protect the designated beneficial uses of surface waters. Currently, stormwater management is regulated at the State level by the Florida Department of Environmental Protection (FDEP), at the regional level by water management districts, and at the local level by local governments. The goals for stormwater management within the State of Florida are outlined in Chapter 62-40 of the Florida Administrative Code (FAC), titled “Water Resource Implementation Rule”. This rule establishes that stormwater design criteria adopted by FDEP and the water management districts shall achieve at least 80% reduction of the average annual load of pollutants that cause or contribute to violations of State Water Quality Standards. When the stormwater system discharges to an Outstanding Florida Water (OFW), the design and performance criteria increases to 95% reduction. A wide range of stormwater design criteria have been implemented within the State of Florida to achieve these minimum stormwater treatment performance standards. However, recent research on the performance efficiency of current stormwater management systems indicates a high degree of variability in the pollutant removal effectiveness of commonly used systems. In addition, stormwater design criteria for the same type of stormwater management system vary widely throughout the State of Florida, which can impact the performance efficiency of stormwater management systems designed in one area compared to another. 1.1 Scope of Work This report provides a discussion of work efforts performed by Environmental Research & Design, Inc. (ERD) for the Florida Department of Environmental Protection (FDEP) as part of Agreement SO108, titled “Evaluation of Current Stormwater Design Criteria within the State of Florida”. The primary objective of this project is to evaluate current stormwater design criteria within the State of Florida and determine if these criteria meet the treatment requirements specified in Chapter 62-40 FAC. If elements of existing stormwater design criteria fail to meet the requirements of Chapter 62-40 FAC, then changes will be recommended to the current rules to improve stormwater management so that the minimum treatment requirements can be achieved. This analysis was also conducted to evaluate existing design criteria for discharges to OFWs which have the goal of 95% pollutant removal. In addition, an evaluation was also performed to quantify stormwater design criteria necessary to achieve a condition of no net increase in loadings for a project site under post-development conditions compared with loadings discharging from the site under pre-development conditions. 1-1
