After going through a treatment and drying process, dried sludge at the Anson-Madison Sanitary District is deposited into a trailer to be trucked to Crossroads Landfill in Norridgewock. The wastewater facility in Madison never allowed the sludge to be applied to farmland, as other facilities in Maine did, a fortuitous decision as the plants now know the material contains PFAS. Credit: Erin Rhoda / BDN

Maine is currently amassing information about the levels of toxic “forever chemicals” present in wastewater to prepare for future regulation of the chemicals.

Since October, 105 public wastewater treatment plants and 19 private wastewater facilities across the state have been regularly testing the liquid waste leaving their facilities, called effluent, for per- and polyfluoroalkyl substances, under a new law that passed in the spring. They will test for about 10 months and are reporting the results to the Maine Department of Environmental Protection.

Statewide results are still being compiled, but many individual wastewater treatment plant operators have said they are finding the chemicals in their treated waste, which gets discharged into waterways that sustain fish and other aquatic life, and sometimes feed communities’ drinking water wells.

While the state continues to assemble the PFAS test results, plant operators are waiting to hear what standards they will have to adhere to in the future. There are limits on the amount of PFAS in drinking water but not on the amount found in wastewater.

“The question right now, and on a state level, too, is what is an acceptable amount?” said Nick Champagne, superintendent of the Kennebec Sanitary Treatment District in Waterville.

PFAS are a class of chemicals used to make products resistant to water, grease and heat, and they build up in bodies and the environment over time. Studies are ongoing, but some have linked certain compounds to kidney cancer, testicular cancer, high cholesterol, decreased response to vaccines, fetal complications and other health problems.

Treatment plants are not the original source of PFAS. Rather the chemicals come to the facilities from industries that use them to manufacture their products; from homes where people wash waterproof clothing and flush human waste containing PFAS down the toilet; and from landfills that need a place to put their PFAS-infused runoff.

Wastewater facilities treat conventional pollutants before discharging their effluent into rivers, but they are not designed to remove PFAS. In addition to being specialized and costly, the technology for PFAS removal systems is still being developed.

An association representing wastewater facilities is hoping that any future limit on PFAS in wastewater takes into account the cost for facilities to overhaul their systems.

“I would like to hope that science and reason will prevail in terms of when you have to balance the cost with the environmental impacts,” said Kirsten Hebert, executive director of the Maine Rural Water Association.

Many wastewater treatment plants across Maine are already dealing with increased costs from having to landfill their semi-solid waste, called sludge or biosolids, which contains PFAS. Last year the Maine Legislature instituted strict restrictions on spreading sludge, prompting the facilities to rely on landfills in Maine, out of state and in Canada.

In the past, many facilities spread their waste solids on farm fields as a type of fertilizer approved by the state government. The PFAS in the waste then seeped into groundwater.

“This has been the primary source of contamination that we’ve been grappling with here in Maine,” Melanie Loyzim, commissioner of the Maine Department of Environmental Protection, told the Maine Board of Environmental Protection on Thursday.

Of approximately 1,500 wells that have been tested so far in Maine, 23 percent have had PFAS levels exceeding Maine’s interim standard of 20 parts per trillion, Loyzim said.

The Waterville treatment plant’s operations offer an example of how connected different waste streams are, how widespread PFAS contamination can become and how expensive it could be for communities to find a fix.

The facility serves Waterville, Winslow, Fairfield and Benton, in addition to paper-plate maker Huhtamaki. It stopped spreading its sludge in 2003, before many other facilities, but over the previous 24 years it got state approval to lay down 285,165 cubic yards of the material, according to state records.

The Waterville wastewater treatment plant’s recent tests have shown PFAS in the total mix of wastewater entering the facility, in the wastewater collected individually from Huhtamaki, in a mix of waste from the two towns of Fairfield and Benton, and in the effluent being discharged out of the facility.

The state’s testing of wells has revealed how Fairfield has so far been hit hardest by PFAS contamination.

As of September, 175 wells in Fairfield had PFAS levels above the state’s standard; 184 wells had detectable levels below 20 parts per trillion; and 53 wells had no detectable amount of PFAS, Town Manager Michelle Flewelling said.

The highest recorded level in a private well in Fairfield was 54,100 parts PFAS per trillion parts water, which is 2,705 times higher than the amount currently deemed acceptable in Maine.

The Waterville treatment plant stopped spreading its sludge on fields back in 2003 not because someone suspected a problem with it but because the spreading operation had become too much to manage, Champagne said.

“The district owned the trucks, and we had employees on staff that were licensed to drive the trucks,” Champagne said. “It became cumbersome to keep the maintenance on the trucks, of course, and then also keeping employees staffed to be able to drive the trucks just became very cumbersome and costly.”

Instead of continuing to spread it, the facility opted to send most of its sludge to the state-owned Juniper Ridge Landfill in Old Town, Champagne said. It also sent a portion to Casella’s Hawk Ridge Compost in Unity to be turned into compost. Hawk Ridge, in turn, sold the compost to garden centers, golf courses, athletic field managers, landscapers and others, according to its past marketing materials.

Now that Maine law prevents Hawk Ridge from using Maine sludge for compost, the majority of the Waterville plant’s sludge is landfilled.

But the option is now proving expensive, in part because of increasing demand for landfill space. In 2021 Juniper Ridge took in 90,069 tons of municipal sludge, up from 36,713 tons in 2017, according to a state filing.

Last year the cost to the Waterville treatment plant of landfilling its sludge went up 50 percent, Champagne said.

“We’re looking at a future now where I’m not entirely sure where that’s going to stop,” Champagne said.

One other landfill, however, has not seen a significant increase in sludge disposal, though costs have still increased. Waste Management’s Crossroads Landfill in Norridgewock has seen “no real increase in volume to speak of,” spokesperson Garrett Trierweiler said.

Still, a number of factors may be contributing to increased costs, he said, including the restrictions on land spreading, fewer disposal options, increasing fuel and transportation costs, and increasing costs to manage the material.

While landfilling sludge appears to be the best available option right now, it is not an ideal long-term solution because PFAS don’t truly go away, Champagne said. The chemicals still ooze out in the form of landfill leachate, which gets sent back to wastewater treatment plants, which flush it into Maine rivers.

Each wastewater treatment plant has different arrangements. For instance the Kennebec Sanitary Treatment District has a contractual obligation to process the leachate from Hawk Ridge’s holding fields, Champagne said. Those holding fields are still generating the liquid even though the facility is no longer distributing compost.

The Waterville wastewater treatment plant also processes trucked-in waste from haulers who pump out residential septic tanks. In November 2021, the wastewater facility tested samples of the septic material and found PFAS.

So while treatment plants are no longer spreading contaminated sludge on fields, the chemicals are still ending up in the environment.

The U.S. Environmental Protection Agency has proposed limits for how much PFAS should be allowed in freshwater to protect aquatic life. But it has not yet proposed a specific level in freshwater aimed at protecting human health. Maine expects the federal government to develop this guideline by the end of 2024.

The Maine Department of Environmental Protection anticipates it will then use the federal criteria to complete state rulemaking by the end of 2025. Then the department could incorporate the new rules into wastewater treatment plants’ discharge permits.

“Without that human health criteria, we really wouldn’t be able to determine what an appropriate discharge limitation would be,” Loyzim said.

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Erin Rhoda

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...