Abstract |
Throughout the U.S. there are thousands of waters listed for impairments from stormwater sources. The most common pollutants coming from stormwater sources include sediment, pathogens, nutrients, and metals. These listed impaired waters need a Total Maximum Daily Load (TMDL), which identifies the total pollutant loading that a waterbody can receive and still meet water quality standards. The TMDL also allocates a specific pollutant wasteload to specific point and nonpoint sources. When the TMDL is implemented, the stormwater wasteload allocation is implemented via the National Pollutant Discharge Elimination System (NPDES) stormwater permitting system. States and EPA Regions have used a variety of methods to develop stormwater source TMDLs during the past decade. With the expansion of NDPES Phase II stormwater to smaller municipalities and smaller construction activities, there has been increasing demand for more detailed quantification of stormwater allocations in TMDLs that are more useful for implementation in NDPES permits. This report summarizes 17 TMDLs that have been developed for stormwater sources in 16 states throughout the country during the past eight years. They represent a range of pollutants, models used, and different allocation and implementation methods that will be helpful to TMDL practitioners and NPDES permitting agencies and permittees as they develop and implement new stormwater source TMDLs. |