MS4 – Stormwater Education Program

An MS4 moves water away from an area to a local water body. The EPA is now requiring certain urbanized municipalities to address storm water quality. The Pennsylvania Department of Environmental Protection has outlined a program for Municipal Separate Storm Sewer Systems (MS4’s). In Pennsylvania Phase I of the program focused on large and medium sized cities above 100,000 population (Philadelphia, Pittsburgh, etc.). Collier Township is one of about 900 municipalities in Phase II of the program. We are required to educate the public as part of a 5 year permit program.

Storm Water Runoff


When it rains, the draining water is called storm water runoff. Storm water can be a problem when there is a decrease in quality and an increase in quantity. Development can alter the natural pathway that storm water takes to travel over land, and increases the rate at which it travels over the land by changing porous surfaces (soil) to non-porous, or impervious surfaces (pavement). Natural surfaces, such as soil, act as a filter for storm water and clean it as it infiltrates into the ground.