Friends of Merrymeeting Bay is calling on state regulators to upgrade the water quality classification the Androscoggin River from Gulf Island north of Lewiston to Lisbon’s Worumbo Mill, arguing the river’s quality has long exceeded minimum standards and now merits a higher classification under state and federal law.

In a 19-page comment submitted ahead of a June 30 deadline, the nonprofit backed a proposal from Grow L+A, a Lewiston-Auburn-based revitalization group, to reclassify the river between Gulf Island Pond and Worumbo Dam from Class C to Class B — and sharply criticized the Maine Department of Environmental Protection for declining to recommend the change.

The group’s argument hinges on a key provision of state law: “When the actual quality of any classified water exceeds the minimum standards of the next highest classification, that higher water quality must be maintained and protected.”

That statute, the group contends, obligates the DEP to recommend the upgrade. “This is not optional,” the group wrote in its submission.

“By law, it should happen,” said Ed Friedman, chair of Friends of Merrymeeting Bay. “If a river consistently meets the standards of a higher classification, the state has an obligation to recognize that. Otherwise, it’s a license to pollute.”

The state’s classification system for rivers ranges from Class D to Class AA. Class AA waters require the highest protection, while Class A waters are suitable for treated drinking water, fishing, recreation and industrial use. Class B waters protect habitat for fish and other aquatic life, and are suitable for recreation, navigation and agricultural/industrial use. Class C waters are considered suitable for navigation, industrial processes and cooling water supply.

Citing more than two decades of field data, Friends of Merrymeeting Bay say the river consistently meets the criteria for Class B waters, including dissolved oxygen levels, bacteria standards, and aquatic life assessments. Just 2% of dissolved oxygen samples fell below the Class B threshold of 7 milligrams per liter. It’s a margin the group described as “within instrument calibration error.” Bacteria testing has also shown consistent compliance with Class B criteria since 2006, according to the group.

In 2021, macroinvertebrate surveys at six sites between Lewiston and Brunswick found that four sites met or exceeded Class B biological standards. The remaining two either met Class C or were located in dam impoundments, which under state law are exempt from the strictest Class B requirements, according to the group.

Friedman said the group has been collecting water quality data in recent months, including helicopter-based efforts to test 10 locations along the river. Five additional surveys are planned before the end of the year. The group expects to have a full season of data to present by fall.

“We’ll have a great profile of the river — some flat water, some moving water, some impoundments,” he said. “That, I think, will provide a really good picture.”

Despite that record, DEP officials declined to recommend reclassification during their recent Triennial Review, saying the river must meet Class B standards 100% of the time to qualify — not just most of the time.

“DEP has been misinterpreting the law for a long time,” Friedman said. “They’ve taken a stand that it has to meet these conditions 100% of the time. Well, that’s not what the Board of Environmental Protection said last time around.”

Friends of Merrymeeting Bay, along with the Conservation Law Foundation and environmental law firm Greenfire Law, argues that DEP is misapplying the law by relying on modeled worst-case scenarios, such as drought conditions and maximum industrial discharge levels, instead of actual water quality data.

“These models do not reflect current conditions on the river,” the group said, calling the agency’s logic “deeply flawed.”

Under both federal and state law, they argue, water quality classifications must be based on uses that are actually being attained. DEP’s reliance on “what-if” scenarios, they say, effectively allows industry to block reclassification — even when data shows the river has recovered.

The group also warned that by refusing to recommend an upgrade, DEP could open the door to future degradation. Class C still allows for the discharge of pollutants that could harm aquatic life and limit recreational use.

“When a water body consistently exceeds the minimum standards of its classification, keeping it in a lower class violates state statute and the Clean Water Act’s anti-degradation rules,” Friedman said. “You’re legally supposed to lock in that progress.”

The group urged the department to reconsider, but said that if DEP holds firm, the Board of Environmental Protection should step in and make the recommendation directly to the Legislature.

“I’m optimistic,” Friedman said. “The board understands the statutes. If it doesn’t work this time, we’ll keep collecting data and come back again.”

A public hearing on the proposal is expected later this year. Until then, Friedman said, the focus remains on building the scientific record.

“The science is clear,” the group wrote in its comments. “The law is clear. It’s time to upgrade this river.”