By definition an MS4 is a system of conveyances that include, but are not limited to, catch basins, curbs, gutters, ditches, man-made channels, pipes, tunnels, and/or storm drains that discharge into Waters of the State. For these conveyances or system of conveyances to be recognized as an MS4, a state, city, town, village, or other public entity must own them. These conveyances must also not be part of a Publicly Owned Treatment Works and may not operate as a combined sewer.
Operators of large, medium and regulated smallMunicipal Separate Storm Sewer Systems are required to obtain NPDES permit coverage in order to discharge pollutants into Waters of the State. These designations (large, medium, and small) are based on urbanized areas as determined by the latest census.
South Carolina has one (1) large MS4 – the South Carolina Department of Transportion and four (3) medium MS4s – City of Columbia, Greenville County, and Richland County. These MS4s receive individual NPDES permits for their discharges.
There are also over 70 regulated small MS4s in South Carolina. The operators of these may choose to receive coverage under a general permit or obtain individual permit coverage.
Download all MS4 related documents including the general permit, worksheets and checklists.
Need to get in touch with an MS4 representative? Check out the MS4 Contact Page for recent regulator information.
All internal and external links related to the MS4 Community.
Large and Medium MS4s must prepare and submit a permit application to address each of the following elements:
Regulated Small MS4s must develop a program to cover each of the following minimum control measures: