As Maine continues trying to grasp the scope and long-term toxic effects of “forever chemical” contamination across its land and waters, scientists have turned their attention to Penobscot Bay.
Little is known about how these chemicals, known as PFAS, travel in marine environments or how they affect organisms there, according to Carey Friedman and LeAnn Whitney, two associate professors at Maine Maritime Academy in Castine who two years ago began sampling around the bay and up the Penobscot River. The researchers set out to discover more about the presence of the chemicals in coastal waters and how they may move through the food web, hoping to help inform new policy around PFAS.
They chose sites from Rockland to Indian Island to Castine, near where effluent is released from wastewater treatment facilities and former mill sites. At one spot in Bucksport, the two were surprised to find concentrations at a mill landfill outflow pipe were more than 10 times higher than other locations — but it’s still unclear what significance that may have.
The work is part of an emerging area of science in Maine researching these compounds in marine environments and their impact on the state as its PFAS crisis and response continue to unfold.
PFAS contamination initially came to light in Maine from sludge used as fertilizer on farm fields. Its effects on people, wildlife and inland water bodies still include unknowns.
The forever chemicals also end up in the ocean through wastewater discharge and sources such as landfill leachate. The current research gaps raise questions, including how they may affect marine life and the state’s cornerstone seafood industries.
Manmade PFAS, or per- and polyfluoroalkyl substances, are used in consumer products and industrial applications like firefighting foam; they break down very slowly in the environment.
Various ones are linked to several health conditions in people, including cancers. There are thousands of varieties of these chemicals but a limited number are understood and tested for.
Six specific compounds are tested when evaluating PFAS levels in drinking water, measured together as their sum in parts per trillion.
Friedman and Whitney compared results to that standard because it’s the federal one available, though it doesn’t apply well to marine waters. They measured 34 compounds overall through a lab at the University of Rhode Island.
They were looking for PFAS concentrations in the bay and for its presence in phytoplankton, which make up the base of the marine food web. That data could help lead to new standards for exposure in aquatic organisms, and to research about how the chemicals move to larger organisms.
They didn’t end up collecting enough phytoplankton for the second goal.
But in Bucksport, they were surprised to learn that untreated leachate from a landfill that once served the town’s paper mill drips into the river from a pipe. Their initial PFAS readings there were at least 10 times higher than other testing locations, but Friedman and Whitney cautioned that their results haven’t been peer-reviewed yet.
In samples collected near the pipe on three different dates in 2024, the researchers found up to 70 parts per trillion as the sum of those six compounds. At the time, Maine’s safety standard was 20 parts per trillion.
The state recently adopted federal drinking water standards of four parts per trillion each for PFOA and PFOS, which are specific “forever chemicals.” At the pipe site, PFOA was 10 times over that limit and PFOS was about twice on one sampling date.
Most other types of PFAS that were measured — those not regulated in drinking water — were also higher at the Bucksport Mill location than other sites, according to Friedman.
Friedman and Whitney originally sampled below the pipe, where chemicals weren’t mixed with water and dispersed like the underwater discharges elsewhere. More sampling in surrounding areas showed the compounds appear to become diluted fairly quickly to non-concerning levels once they got farther out into the river.
But what that could mean for the marine ecosystem isn’t clear yet.
“We know that we measured pretty high concentrations there, but beyond that we’re not sure how to interpret the risk,” Friedman said.
The landfill is now owned by a subsidiary of American Iron & Metal, the scrap metal company that bought the former Verso paper mill and its holdings after its 2014 closure.
The state has ordered the dormant landfill formally closed by Dec. 31 this year.
Officials and residents have pushed the state to require leachate treatment and PFAS management in its closure plan, among other measures, concerned that the proposal won’t be enough to protect public health and natural resources for future generations.
Leachate is a main concern and, before the mill shut down, was treated before discharging in the river, according to the town.
“The decisions made during this closure process will have permanent consequences, and it is imperative that the Department hold the applicant to the highest standards of protection,” Town Manager Jacob Gran wrote to the Department of Environmental Protection in October, responding to its review of the company’s initial closure application.
Friedman said any user of the former mill property should be aware of the leachate if it continues. That could apply to the land-based fish farm once proposed for part of the property, Whole Oceans, though residents now generally doubt it will ever break ground.
Just downriver, readings weren’t worrisome near where Bucksport’s wastewater treatment plant releases treated effluent, Friedman said. They also tested Silver Lake, the town’s source of drinking water, and found levels safe by current standards.
The Penobscot River is already closed to lobster and crab harvesting for miles in Bucksport and beyond due to mercury contamination from the former Holtrachem plant in Orrington, roughly 12 miles upriver. The factory discharged an estimated 6 to 12 tons into the river in the 1960s and ’70s.
How that mercury may interact, or not, with PFAS is also unclear; so is the number of compounds in the river and bay.
Identifying contaminants in the environment is like a game of whack-a-mole, according to Friedman, as new chemicals are created to replace ones that are regulated out of use. Scientists trying to keep pace essentially play a detective game, especially with proprietary formulas.
“The science community at large is still trying to get a handle on the big picture of all PFAS compounds that have entered the environment,” she said. “In some cases, we don’t even necessarily know what they look like.”
Friedman and Whitney hope to return to the Bucksport mill landfill pipe site this summer to sample sediment and organisms that stay in one place, like clams and mussels.
Elsewhere in Maine, scientists from the Department of Environmental Protection, University of Maine, and Mount Desert Island Biological Laboratory are researching PFAS on the coast.
The Shaw Institute in Blue Hill last summer announced a pilot study with UMaine to explore how exposure to PFAS affects young lobsters, calling the chemicals a new challenge to the state’s core lobster industry.
“While Maine has been at the forefront of mitigating PFAS exposure, particularly in agriculture, the impact on its vital marine resources, especially at early life stages, remains largely unknown,” the institute said.
East Boothbay-based Bigelow Laboratory for Ocean Sciences and Friends of Casco Bay recently finished a two-year study looking for land-based sources of PFAS in that bay and collecting data to help find out whether levels pose risks to aquatic life.
That study’s conclusions noted the effects of thousands of types of PFAS are still unknown and researchers can’t say they aren’t harming aquatic organisms.
The work has opened the door to a whole new set of questions, in Whitney’s view, and more collaborations could happen as scientists try to put together the most complete story they can – but that’s not always straightforward.
“I think we will always have new questions to ask, and that’s the exciting part of science,” she said. “At the same time, it makes it challenging to fully understand the complex dynamics of marine ecosystems. Science rarely fits neatly into a box.”
