
The new MS4 permit will go into effect in July of this year. In the Casco Bay watershed, it applies to twelve municipalities and specifically regulates stormwater pollution in their most densely populated areas. The municipalities include Scarborough, Cape Elizabeth, South Portland, Portland, Falmouth, Cumberland, Yarmouth, and Freeport along the coast, as well as inland communities such as Windham, Westbrook, and Gorham.
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,” says Doug. “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.”
MS4 permits, like all Clean Water Act permits, are renewed every five years. The renewal process provides the opportunity to assess if the permit sufficiently protects water quality or if there are improvements that need to be made. The process also allows for incremental advances that recognize budget constraints, developments in knowledge and technology, and the reality of what can be accomplished in five years.
MS4 permits that apply to municipalities are required to contain “clear, specific, and measurable” terms to address stormwater pollution, according to a federal court ruling from 2003. In short, this ruling required environmental agencies like the Maine DEP to clearly describe how permitted municipalities should address stormwater pollution. When Maine’s MS4 permit was due to be renewed in 2018, Ivy knew there were important improvements to be made. The last version of the permit issued in 2013 did not include “clear, specific, and measurable” terms to reduce pollution.
“The requirement to set forth ‘clear, specific, and measurable’ terms in MS4 permits may be the best thing to happen for our watershed in a long time,” explains Ivy. “It fundamentally changed how MS4 permits could be written and gave Friends of Casco Bay the foundation to advocate for new permit language that will effectively reduce pollution from past actions and ensure future development does not degrade our waters.”
When the state began the permit renewal process in 2017, Ivy submitted comments on the first draft advocating for these new terms. However, for DEP and many municipalities, implementing a stronger MS4 permit would require valuable time and resources. Over the next four years, Ivy continued to advocate for stricter standards and filed more than eight sets of comments on drafts of the permit.
Ultimately, Friends of Casco Bay filed an appeal to the Maine Board of Environmental Protection asking that the new “clear, specific, and measurable” terms that Ivy had advocated for be included in the permit. In the summer of 2021, the Board of Environmental Protection sided with Friends in the appeal, and Maine’s new MS4 permit was finalized on December 23. In order to provide DEP and affected municipalities additional time to prepare to implement the new terms, it was agreed that the permit would officially go into effect on July 1, 2022.
Will Everitt, Interim Director of Friends of Casco Bay, sees this victory as a great example of how Friends works. “This was a long and challenging process,” says Will. “The way we advocate for the health of the Bay is just as important as what we achieve. We have deep respect for the DEP and affected municipalities. While we sought to address what may be the biggest source of pollution into the Bay, we also worked hard to collaborate with our partners and listen to concerns throughout the process.”

Today, there are more people living by and working on Casco Bay than ever before, and as our communities grow, so do our impacts on the health of the Bay. Climate change brings additional challenges to the coast, such as altering ocean chemistry and intensifying rainstorms that will send more stormwater into Casco Bay.
Damon Yakovleff, Environmental Planner at the Cumberland County Soil and Water Conservation District, provides technical support to municipalities on stormwater and sustainability projects. “This permit is a part of the broader effort to make this a truly sustainable region that treads more lightly on the environment,” says Damon. “It matters in a holistic way. It is about preventing water pollution, but it goes far beyond that. It’s about supporting our economy, culture, and quality of life.”
The MS4 permit’s new stormwater protections that go into effect beginning this year will help reduce these threats. A healthy Bay is a resilient Bay. With less pollution flowing to our coastal waters, Casco Bay and our coastal communities will be better prepared to withstand the challenges we know are looming on the horizon.