The Clean Water Act is the federal legislation that governs stormwater management. Stormwater point discharges to waters of the U.S. are regulated using National Pollutant Discharge Elimination System (NPDES) permits. In 1999, federal regulations extended coverage of the NPDES program to local separate storm sewer systems (MS4’s) serving populations less than 100,000. Horsham Township is required to comply with the NPDES program as a MS4. Under the NPDES stormwater program, permittees must develop a stormwater management plan that provides the details of how the community (Horsham Township ) will comply with the requirements of the permit. Permits are based on a framework of six minimum control measures:

• Public education and outreach
• Public participation and involvement
• Illicit discharge detection and elimination
• Construction site runoff control
• Post-construction storm water management in new development and redevelopment
• Pollution prevention and good housekeeping for municipal operations and maintenance

More information on this program is available from the Pennsylvania DEP website.