The Municipal Separate Storm Sewer System (MS4) is required under the United States Environmental Protection Agency (EPA) National Pollutant Discharge Elimination System (NPDES), a federal program designed to eliminate storm water pollutant discharges to receiving waters of the United States.
In 1996, the first five-year permit (NPDES Permit No. ALS000003) was issued to Shelby County and its eight additional co-permittees. In October 2001 the second term, five-year Municipal Separate Storm Sewer System (MS4) permit was issued and administratively extended through order of ADEM. Shelby County acted as lead permittee for the Shelby County MS4 permit from 1996-2015.
On October 1, 2015, ADEM issued the new individual MS4 permit to Shelby County (NPDES Permit No. ALS000008); ending the previous co-permittee configuration. The goal of the MS4 Storm Water Program is to reduce Non-Point Source (NPS) pollution, which occurs from rain runoff from various sites.
The Municipal Separate Storm Sewer System (MS4) permit requires six basic elements to be implemented:
Construction Site Runoff Program
Industrial / High-Risk Program
Pesticide, Herbicide, and Fertilizer Application Program