New Permit Better Controls Pollution from Stormwater Runoff

Stormwater runoff from impervious surfaces like roads and rooftops is a major source of water pollution. As rain and snowmelt flow over asphalt, concrete and roofs they pick up oil, pesticides, sediment and bacteria. When this untreated runoff enters streams and lakes it can contaminate drinking water, harm aquatic life and cause flooding.

Many towns use municipal separate storm sewer systems (MS4s) that convey runoff through pipes and discharge directly into waterways. Under the Clean Water Act, MS4 operators must obtain a National Pollutant Discharge Elimination System (NPDES) permit. Pennsylvania’s Department of Environmental Protection issues these permits, but the second general MS4 permit adopted in 2013 was inadequate. PennFuture appealed approval of coverage for Upper Gwynedd Township.

After more than a year of negotiations, a stronger general permit took effect in March 2018. It requires municipalities in urbanized areas to better control stormwater pollution through improved planning and controls. PennFuture sees this as an important step toward cleaner streams and urges municipalities to implement the new requirements fully.