The secondary clarifier at the city of Bangor Wastewater Treatment Plant on Main Street is pictured in March 2023. Credit: Linda Coan O'Kresik / BDN

The Bangor Wastewater Treatment Facility is discharging the greatest amount of “forever chemicals” of any other wastewater facility in the state, according to the results of wastewater testing that is the first of its scope in Maine.

It’s not yet known where the per- and polyfluoroalkyl substances, or PFAS, are coming from precisely and why Bangor released the greatest number of pounds of the chemicals over six months in its wastewater effluent, which flows into the Penobscot River.

But the city recently volunteered to be the first community in Maine to participate in an effort with the Maine Department of Environmental Protection to investigate the origins of the chemicals, beginning later this summer, said Amanda Smith, Bangor’s director of water quality management. Smith anticipated having a large amount of PFAS because Bangor is among the state’s biggest wastewater facilities, but she was surprised to see the city had the most at an estimated 3.5 pounds per year.

“That puts us in a higher position than I thought,” Smith said. “This is really uncharted territory nationwide, and Maine is very much ahead of the curve on this. Bangor will be spearheading the research on the sewer system.”

pfas reporting in maine

Under LD 1911 passed last year, Maine lawmakers required wastewater treatment facilities to test the wastewater leaving their plants for six compounds to better understand the extent of PFAS contamination in Maine rivers. The facilities are not set up to filter out PFAS, which do not break down naturally and have been linked to a number of serious illnesses. Certain PFAS are known to accumulate in humans, wildlife, fish and plants, but there are no regulations limiting the amount of PFAS in wastewater.

Public and private wastewater treatment facilities began testing their treated effluent each month starting in October. If the first six months of available data from the 105 facilities are averaged over a year, they are estimated to release an annual total of 24.89 pounds of PFAS into Maine rivers, some of which feed public drinking water systems.

The federal Toxics Release Inventory is supposed to gather similar information nationwide, but a loophole has continued to allow manufacturers to not disclose the PFAS they release. So this data represent the first broad look at PFAS contamination in Maine wastewater.

While the test results are public, the Maine Department of Environmental Protection has not released them widely. Nathan Saunders, a licensed environmental engineer and resident of Fairfield, requested them and shared the state’s correspondence with the Bangor Daily News. Saunders analyzed the results to come up with the total pounds of PFAS being released each year.

The annual estimated total of 24.89 pounds of PFAS might not seem like a lot, Saunders said. But for a comparison, it’s enough to contaminate the amount of water consumed by Maine’s adult population for more than 1,000 years given how near-zero amounts of the chemicals are considered toxic. Maine has a limit of 20 parts per trillion for six types of PFAS either individually or combined.

The federal government has proposed establishing an even stricter standard for PFOA and PFOS, two of the most studied compounds, at 4 parts per trillion in drinking water. That’s the equivalent of one drop of water in five Olympic-sized swimming pools.

The 24.89 pounds of PFAS is “a very underwhelming number until you determine how many gallons of water can be contaminated by the drinking water standard by that amount of PFAS. And those numbers are astronomical,” Saunders said.

While the state agreed with Saunders’ math, it is also conducting its own analysis of more months of data and may post its report online in September, said David Madore, deputy commissioner of the Maine Department of Environmental Protection.

In terms of takeaways from the data so far, PFAS are detectable in effluent from every wastewater facility, which “is an indication of the prevalence of PFAS in our society,” Madore said. The results are also fairly consistent month to month.

The DEP plans to conduct more intensive testing of wastewater effluent and influent at facilities with higher-than-average amounts of PFAS to “determine potential sources and investigate opportunities for reduction of PFAS at the source,” he said.

Scientists are still working to understand the risks of long-term, low-level PFAS exposure, but potential health effects include: increased risk of prostate, kidney and testicular cancers; interference with the body’s hormones; increased cholesterol or risk of obesity; reduced ability to fight infections; and decreased fertility or increases in high blood pressure in pregnant women.

The ecological risk from PFAS is more unknown. The Interstate Technology Regulatory Council explains how “little is known about whether or how these exposures are translating into adverse effects in wildlife,” but that “even extremely low or undetectable concentrations of PFAS in the environment may present potential health risks to organisms.”

While PFAS do not break down, they do move. Once in rivers, the chemicals have been found to flow to the sea and circulate in ocean currents. PFAS have been found in remote regions of the world, including in Arctic polar bears. Once applied to the ground, PFAS have spread to drinking water wells.

“I don’t have a good meter of environmental damage that this is causing, but the potential of this chemical to contaminate is enormously large, and once it’s contaminated it’s going to be there for a long, long time,” Saunders said.

He has closely watched how Maine has responded to the discovery of PFAS in the environment ever since he and other Fairfield residents recorded very high levels of the chemicals in their wells. Saunders and others have filed a lawsuit against paper mills and other companies over the spreading of their PFAS-laden sludge on fields. His drinking water well tested at an average of 14,800 parts per trillion for PFAS in 2021.

Jean MacRae, associate professor of civil and environmental engineering at the University of Maine, examined the results from Maine’s first widespread testing of wastewater for PFAS and saw they are largely in line with concentrations reported in research, with a few exceptions. In general, wastewater coming from industrial sources results in higher concentrations of PFAS.

“This has been seen elsewhere and that seems to agree with the data here,” she said.

Smith, with Bangor’s wastewater facility, noted that facilities with more PFAS tend to accept landfill leachate, which is the liquid that accumulates after passing through a landfill. It can either be piped into a wastewater treatment facility, as is the case for the leachate from Pine Tree Landfill in Hampden that is treated in Bangor, or it can be trucked to a treatment facility.

“When you look at any of the plants with the higher concentrations, they all can be directly correlated to a landfill component,” Smith said.

The Kennebec Sanitary Treatment District in Waterville released the second greatest amount of PFAS in its effluent, followed by the Anson-Madison Sanitary District, Twin Rivers Paper Co. in Madawaska, the paper mill operated by Pixelle Specialty Solutions (formerly Verso) in Jay, the Portland Water District, Sappi paper mill in Skowhegan, and the Greater Augusta Utility District, followed by the Lewiston-Auburn Water Pollution Control Authority, according to the compilation of PFAS test results taken each month from October through March.

long-term pfas effects

They emit more PFAS because they are the bigger facilities in Maine and process lots of wastewater. For MacRae, the numbers that were most surprising came from the Somerset County town of Hartland. While the Hartland Pollution Control Facility’s flow is relatively small, the concentration of PFAS being released is high: an average of 828 parts per trillion over six months. Only the Anson-Madison Sanitary District saw a higher concentration at an average of 848 parts per trillion over six months.

The third highest concentration came from Brunswick’s Graham Road Landfill at an average of 218 parts per trillion over six months. The fourth highest concentration came from Sappi’s Westbrook location at an average of 172 parts per trillion over six months.

At the Bangor Wastewater Treatment Plant, some PFAS are coming from residential households, but “we have to have concentrated sources coming from somewhere” to reach the levels discovered in recent testing, Smith said. Bangor’s wastewater tested at an average of 149 parts per trillion over six months.

Bangor will be working with the DEP in the coming months to test different spots in the sewer system to figure out the origins of the PFAS. They will start with 40 different locations, Smith said.

“This research will help us find out if there’s anything else of concern coming in besides that leachate,” she said. “We don’t know yet, but we did volunteer to get first in line, so we should get some really good answers this fall.”

See the PFAS test results here.

Erin Rhoda is the editor of Maine Focus, a team that conducts journalism investigations and projects at the Bangor Daily News. She also writes for the newspaper, often centering her work on domestic and...