It may be hard to believe, but stormwater, rain and snow melt running off of pavements that are covered by impenetrable materials such as asphalt, concrete, brick, stone—and rooftops, are significant causes of water pollution. 

As the stormwater runs over these impervious surfaces, it collects pollutants, including oil, pesticides, sediment, and bacteria.  Untreated stormwater runoff entering our streams can result in the contamination of our drinking water supplies; prohibitions on swimming, fishing or boating uses; injury or death to aquatic plants and animals; dangers to public health; and increased flooding.  

In many places, this stormwater runoff is conveyed through distinct sewer pipes that bypass the wastewater treatment plants and discharge the polluted runoff directly into our streams and lakes. This system is known as a “municipal separate storm sewer system” or MS4.

Luckily, there are laws that protect our waters from polluted stormwater runoff. For example, stormwater from MS4 in urbanized areas is controlled through a National Pollutant Discharge Elimination System (NPDES) permit under the federal Clean Water Act. 

The Pennsylvania Department of Environmental Protection (PADEP) implements this program and issues permits allowing the discharge as long as the permittee complies with the permit requirements. PADEP issued its first general permit for MS4s in 2003. Although each permit is only supposed to be effective for five years, the PADEP’s second MS4 general permit did not become effective until 2013.

Even then, after more than 10 years of the program’s implementation, this second MS4 permit was woefully insufficient. PennFuture took issue with the inadequacy of the PADEP’s MS4 program and filed an appeal of PADEP’s approval of coverage under the MS4 general permit for Upper Gwynedd Township.  (PA Environmental Hearing Board Docket No. 2013-105-L). You can read more about PennFuture’s claims here. 

After more than a year of negotiations, PennFuture and PADEP entered into a settlement which addressed PennFuture’s most important objections, including providing an opportunity for public participation and requiring a demonstration that determined pollution reductions would occur.  As a result of PennFuture’s challenge, the subsequent permit is much more protective of our waters. This new, more protective permit goes into effect this Friday, March 16. 

The new permit includes the six minimum controls of public education and outreach on stormwater, public involvement and participation, illicit discharge detection and elimination, construction site stormwater runoff control, post-construction stormwater management, pollution prevention and good housekeeping of municipal operations.

The PADEP 2018 general permit also requires MS4 permittees discharging into waters impaired as a result of sediment and nutrient pollution to include a plan on how to achieve reductions in these pollutants over the five year term of the permit. Implementation of these plans to reduce pollutants will advance Pennsylvania’s efforts to reach pollutant reduction targets in the Chesapeake Bay TMDL.

Over the past few months, PADEP has reviewed these plans for sufficiency and compliance with the permit requirements.  We have high hopes that the 2018 permit will help protect and improve Pennsylvania’s waters and look forward to working with PADEP and municipalities alike to ensure the permit is appropriately implemented.