MS4 is short for "Municipal Separate Storm Sewer System." A separate storm sewer system is a collection of structures, including retention basins, ditches, roadside inlets, and underground pipes, designed to gather stormwater from built-up areas and discharge it, without treatment, into local streams and rivers.
Wondering what this has to do with you? We are all part of a watershed. Watersheds are land areas that drain to the nearest body of water. In eastern Pennsylvania, local lands may ultimately drain to the Chesapeake Bay. Smaller local creeks and streams also eventually drain to a larger water body, such as the Bushkill Creek emptying into the Delaware River.
Watch the video below by the Penn State Extension to learn how MS4 impacts you and our city in the forms of flooding, pollution, streambank erosion, sedimentation, and more issues.