more... > Water Issues > Quality > Stormwater > Urban Stormwater > Stormwater Phase II [Image: Stormwater] The EPA Stormwater Phase II program went into effect March 10, 2003 for urbanized areas with population densities of over 1,000 people per square mile and other designated areas. At this time the Stormwater control program for all small construction sites (1 to 5 acres) also went into effect. The program requires all affected areas to obtain a general permit and to file a Stormwater Management Plan for their Municipal Separate Storm Sewer System (MS4). Urban Stormwater [Image: One way to help keep urban stormwater clean] Urban areas with their concentrations of people, vehicles, homes, parking lots, streets, small and large business, industry and sewage can create heavy loads of pollutants in their Stormwater runoff.