Canonsburg Borough MS4/Stormwater Management

What is an MS4?

MS4 stands for Municipal Separate Storm Sewer Systems (MS4) which are a conveyance of separate storm structures including catch basins, storm drains and sewers, ditches, etc. that discharge into the waterways of the Commonwealth. The MS4 program is only for separate storm sewer systems and NOT sanitary or combined systems.

A municipality is considered an MS4 when there is urbanized area within the bounds of the municipal boundary determined by the US Census Bureau. The MS4 program is monitored and issued by the US Environmental Protection Agency (EPA) and the Pennsylvania Department of Environmental Protection (PADEP).

Canonsburg Borough is a municipality under the PAG-13 Municipal Separate Storm Sewer System (MS4) Permit (NPDES Permit No. PAG136103). Permittees under the MS4 permit are responsible for the pollutant load and stormwater runoff within the MS4’s urbanized areas that are discharging to downstream storm sewers or waters of the Commonwealth. Under this permit, the Borough is required to address these pollutant control measures by informing the community on stormwater and how the community can assist the Borough in meeting their stormwater management requirements.

Illicit Discharge Flyer
What is Illicit Discharge?


An illicit discharge is any discharge to a municipal separate storm sewer system that is NOT a stormwater ONLY discharge. Examples of illicit discharges include dumping materials in an inlet or stream (paint, construction materials – asphalt, concrete, etc., househouse waste/materials – oils, gas, leaves, grass clippings, etc.). For more information on illicit discharge please view the US EPA Illicit Discharge Detection and Elimination Program Development Sheet or the Illicit Discharge flyer with Borough contact information.

EPA Illicit Discharge Detection & Elimination Program Development

If you think you may have identified an illicit discharge, please complete the form below and submit to:

Borough of Canonsburg
68 East Pike Street, Canonsburg, PA 15317
P: 724-745-1800  |  F: 724-745-8850


For additional information or questions pertaining to stormwater management/Canonsburg Borough's MS4 program, please contact:

Marisa Brletic, Project Manager
KLH Engineers, Inc
mbrletic [at]

Page Last Revised: 2/14/24