Home » Clean Water Act Stormwater Permit Will Dramatically Reduce Pollution

Clean Water Act Stormwater Permit Will Dramatically Reduce Pollution

June 28, 2022

Robby Lewis-Nash, Staff Writer
Friends of Casco Bay
(413) 695-3306
robbylewisnash [at] cascobay [dot] org

Clean Water Act Stormwater Permit Will Dramatically Reduce Pollution

As the Clean Water Act turns 50, much needed updates to a key stormwater permit in Maine will go into effect on July 1 to help reduce pollution and protect Maine waters from climate change 

South Portland, ME: New protections to reduce stormwater pollution flowing from the most urbanized communities in Maine will go into effect on July 1, under a revised version of a critical Clean Water Act permit: Maine’s General Permit for the Discharge of Stormwater from Municipal Separate Storm Sewer Systems (MS4). 

Maine’s revised MS4 permit affects numerous municipalities across the state, including communities in the greater Portland region, the Lewiston-Auburn area, and greater Bangor. The permit includes three major updates that are expected to significantly reduce stormwater pollution into Maine’s rivers, lakes, and coastal waters. Municipalities that fall under the permit will be required to:

  • Test stormwater outfalls to identify and eliminate sources of bacterial contamination
  • Take three actions to restore water quality and reduce pollution from their stormwater systems where they flow into impaired waters
  • Develop and adopt an ordinance to require new construction and redevelopment to use low impact development techniques that allow stormwater to flow more naturally and carry less pollution into stormwater systems.
Casco Baykeeper Ivy Frignoca speaks to an audience about excess nitrogen and stormwater pollution.

These new terms were added to Maine’s MS4 permit after the Maine Department of Environmental Protection was ordered to include them by the Maine Board of Environmental Protection, which sided with Friends of Casco Bay in an appeal last summer. The addition of these terms marks the first time that Maine’s MS4 permit meets a 2003 federal requirement to include “clear, specific, and measurable” terms to reduce stormwater pollution.

Tackling stormwater pollution is long overdue in Maine, according to Ivy Frignoca, Casco Baykeeper with Friends of Casco Bay. “This is a time to celebrate,” said Frignoca. “This permit should have huge and visible results for our watershed, and what better year to have it take effect than 2022, the 50th Anniversary of the Clean Water Act. Stormwater harms the Bay in so many ways because it carries diverse and varying loads of pollutants. As climate change brings more and stronger storms to Maine, the impacts of stormwater pollution will worsen without these changes.”

Stormwater pollution is related to climate change in two major ways. First, Meteorological data show Maine’s annual rainfall has increased six inches since 1895, and Maine’s average annual number of intense storms has increased, particularly since the mid-2000s. Both of these trends exacerbate stormwater pollution and are expected to continue with climate change. Second, stormwater pollution directly harms the health of aquatic ecosystems and fisheries, and healthy ecosystems are more resilient to climate change. 

Doug Roncarati is a Stormwater Program Coordinator for the City of Portland. “Everything we do on the landscape has the potential to create some kind of pollution,” said Roncarati. “The environment is very resilient, but throw too much at it over time and it will break down. We protect the environment and the long-term economic wellbeing of our communities by being thoughtful in how we manage our water resources. The MS4 permit is one way we can do that.”

Maine’s MS4 permit applies to “urbanized areas” within municipalities, as defined by the US Census. In the Casco Bay watershed, municipalities containing urbanized areas include Cape Elizabeth, Cumberland, Falmouth, Freeport, Gorham, Portland, Scarborough, South Portland, Westbrook, Windham, and Yarmouth. 

A map of MS4 program in the Casco Bay Watershed
A map of MS4 communities in the Casco Bay watershed, provided by the Casco Bay Estuary Partnership.

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