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Fact Sheet: Presumpscot River Discharge Moratorium, LD 1926

Protect the restored health of the lower Presumpscot River: the largest freshwater source to Casco Bay

LD 1926, An Act to Impose a Moratorium on New Point Source Waste Discharge Licenses on the Lower Presumpscot River, places a four-year moratorium on new pollution discharges into the river from downtown Westbrook to head of tide.

Presumpscot Falls is a natural haven that many visit for recreation and solace in the middle of Maine’s most densely populated and continuously developing region. The Falls are located in the lower Presumpscot River, which currently has only Class C protections.

This bill provides emergency, temporary, and necessary water quality protection for the lower Presumpscot River. This section of the river is designated a Class C water, though it functions at or near Class B following years of restoration efforts.* LD 1926 places a four-year moratorium on new point source discharges into the lower Presumpscot River. Temporarily preventing new discharges will protect the Presumpscot’s substantial restorative gains in water quality until stakeholders agree on a plan for long-term protection.

  • The lower Presumpscot River is designated as Class C, but in almost all respects meets the higher Class B water quality standards. This is a remarkable improvement in water quality as the lower Presumpscot was once known as “the dirtiest little section of river in the state,” and could not meet Class C standards.** 
  • The Presumpscot River drains two thirds of the Casco Bay watershed. The river has a significant influence on the health of the Casco Bay estuary and its many species that depend on both fresh- and saltwater habitat. 20% of Maine’s population lives in the Casco Bay watershed, an area that represents only 3% of land in Maine. 
  • This four-year moratorium will preserve the river’s significant advances in water quality. These advances have restored habitat for fish, birds, and other wildlife. At the same time, the lower Presumpscot has seen a surge in recreational use and property values along its shores. This section of river flows through Maine’s most densely populated and ever growing region, from revitalized downtown Westbrook to head of tide in Falmouth. 
  • The moratorium allows for continued operation of existing discharges and will not thwart urban growth. The existing discharges are the Portland Water District, Westbrook Wastewater Treatment Facility, and the Sappi Mill. They are all permitted with ample discharge capacity to treat current and future wastewater loads, and to continue commercial operations. 
  • The four years allotted in this moratorium will allow sufficient time to finish studies of the lower Presumpscot River and determine appropriate means of protecting water quality, including a potential upgrade to Class B status. 

*Under the Clean Water Act, bodies of water in Maine are classified as Class AA, A, B, or C based on their health. Class AA and A waters are the healthiest and receive the highest protections. Class C waters allow for some modification to natural conditions caused by human activity, but must still be swimmable, drinkable, and fishable.
Robert M. Sanford et al., River Voices: Perspectives on the Presumpscot, North Country Press, Unity, ME, 2020. p. 239.

The Presumpscot to Casco Bay:

  • The lower Presumpscot River flows through downtown Westbrook, along the northern border of Portland, to head of tide in Falmouth. 
  • The Presumpscot provides habitat for fish that live part of their life in the ocean and part in rivers, including commercially important species like alewives and American eels. The only remaining area for commercial elver fishing is just below the head of tide. The river also provides nesting and hunting grounds for many sea birds. 
  • The Presumpscot is the largest river that flows into Casco Bay. Its freshwater inputs to the bay support the health of the estuary, including the nursery grounds for countless species. We need a healthy Presumpscot River to have a healthy Casco Bay. 
  • Together, the environmental health of the Presumpscot River and Casco Bay sustain our regional economy and quality of life. These waters draw many to the region for work, play, and solace. 
  • The lower Presumpscot River is heavily used for recreation. People swim and fish in areas that were once too polluted for human contact and fish consumption. The lower Presumpscot hosts public trails, preserves, and boat launches. There are many areas for fishing, as well as locations for swimming, tubing and white water kayaking. Its waters flow past Maine Audubon’s Gilsland Farm as it enters the bay, another highly visited nature preserve that showcases the ecology of the estuary, such as jumping sturgeon.
  • The lower Presumpscot River is rich in indigenous and colonial history. In 2019 the Falmouth Town Council adopted a resolution designating this stretch of the river “The Lower Presumpscot Historic and Natural River Corridor.”
Whitewater kayakers paddle Saccarappa Falls in Westbrook (credit:

Fact Sheet: Presumpscot River Discharge Moratorium, LD 1926