The Presumpscot River in downtown Westbrook last week. Brianna Soukup/Staff Photographer

Environmental groups are celebrating a new bipartisan state law that bans new waste discharges into the lower Presumpscot River for the next four years.

The Friends of Casco Bay and the Friends of the Presumpscot River say the law signed by Gov. Janet Mills will provide them with valuable time to create a long-term plan for protecting the river.

“This is a tremendous victory for the river and for Casco Bay,” said Will Everitt, the executive director of the Friends of Casco Bay. “It gives us four years to work with state and federal agencies to make sure that we lock in protection for the health of the river and the health of the bay.”

Snaking through Cumberland County for nearly 26 miles, the Presumpscot River drains two-thirds of Casco Bay’s watershed, is home to an abundance of wildlife, and is a source of recreation and joy for residents of the Casco Bay region. For the last several decades, cleaning the lower Presumpscot – a roughly eight-mile stretch from downtown Westbrook to the Portland-Falmouth border – has been a hard-fought battle.

Maine law requires that businesses, individuals or municipalities seeking to dispose of waste in a body of water must obtain a waste discharge license. Under the four-year moratorium, no new waste discharge licenses will be issued for the Lower Presumpscot until Jan. 1, 2028. Current license holders will not be affected.

Throughout much of the 20th century, the Lower Presumpscot was so polluted that use of the waterway was limited for both humans and wildlife.


The pollution was caused by the saw mills and cloth mills that lined the lower river, inundating it with waste discharges. Additionally, near-total damming on the upper river exacerbated pollution by stagnating water as it traveled downstream, leaving some sections of the lower river with no dissolved oxygen and no way to sustain life.

The Haskell Silk Mill was constructed at a new site upriver in Westbrook in 1901-1902. The brick mill was state of the art, run by electricity and had its own separate dye house. The old mill was on Bridge Street in downtown Westbrook. (Collections of Walker Memorial Library, courtesy of, item #34345)

“I remember as a kid in the mid-’50s … that the lower river ran the color of caramel,” said Sandy Cort, a founding board member and treasurer of the Friends of the Presumpscot River. “There were huge mounds of foam that would float down the river. It smelled horrible.”


In 1972, the passage of the Clean Water Act ushered in both policy and cultural shifts that led to the rehabilitation of water bodies across the country. In the years since, the quality of Presumpscot River water has gradually improved, in part due to stricter standards for treating and disposing of wastewater.

A cyclist crosses the Presumpscot River in downtown Westbrook last week. Brianna Soukup/Staff Photographer

“It was once known as the dirtiest little river in Maine,” Everitt said. “Today, when you walk along Portland Trails along the river, you see kids swimming in there in the summer, you see people fishing, the alewives have come back. It’s made a remarkable turnaround.”

Under the Clean Water Act, Maine’s four freshwater river classifications include AA, A, B and C, with Class AA waters being the least degraded and Class C waters being the most degraded. Waters with higher ratings, or less pollution, are subject to stricter protections. Currently, the state designates the Lower Presumpscot River as a Class C water. There were no discharge applications pending when the bill was introduced.


The rest of the Presumpscot, stretching from Sebago Lake to Saccarappa Falls, is composed of Class A and Class B waters. This section of the river has historically been free from heavy industrialization, leading to its higher rating.

In 2020, Friends of the Presumpscot Co-Founder Will Plumley filed an application on behalf of the group to get the lower river upgraded to Class B, which would permanently strengthen state protections on the river’s environmental health. Though he says that the lower river exceeds Class C requirements, as well as most Class B requirements, the Maine Department of Environmental Protection did not recommend the change based on the water quality data at the time.

Kate Christensen, of Portland, swims at Presumpscot Falls Park in Falmouth last week. Brianna Soukup/Staff Photographer


According to Casco Baykeeper Ivy Frignoca, a leading advocate and expert at Friends of Casco Bay, the four-year freeze on new discharges was designed to give researchers time to either prove to the state that the river should be reclassified or get it to the point where it’s ready for reclassification.

“What we want to move forward with is to make sure that we can preserve the really significant improvements in water quality that have been made and to keep the river healthy going into the future,” Frignoca said. “Whether that happens by seeing if the data is good enough to be upgraded to Class B or through other means, still remains to be seen. It’s going to be driven by the data.”

Though the moratorium means that researchers’ work has just begun, Frignoca hopes that the new law – and the Legislature’s unanimous support for it – will help people understand the importance of rivers in local ecosystems and communities.

“I hope that, like the Legislature, people see and appreciate the connection between healthy rivers and a healthy Casco Bay and that they see that working to improve and protect water quality benefits … the quality of the environment, the quality of our life and what we’re able to do along the water,” Frignoca said.

Paul Montgomery, right, and Kate Christensen, both of Portland, sit on the bank at Presumpscot Falls Park in Falmouth after swimming in the river last week. Brianna Soukup/Staff Photographer

Everitt hopes that the new law will breathe even more life into the river as a stronghold of the Casco Bay community.

“Visit the Presumpscot River,” he said. “Walk on Portland Trails and the Westbrook River Walk, or go up to the Eastern Prom … and look at where the mouth of the river comes into Casco Bay. Really take in what a special place this is.”

Comments are no longer available on this story