AUBURN — Officials are working toward reopening the composting facility operated by the Lewiston Auburn Water Pollution Control Authority, which was forced to close in 2018 due to groundwater contamination.

But, according to wastewater staff, it may be slow going even after the City Council on Tuesday approved amendments to its agreement with LAWPCA intended to simplify the operation.

While the Penley Corner Road facility’s closure at the time was unrelated to statewide concerns over a sewage sludge contaminant linked to cancer and other ailments, its ability to reopen is now closely linked to state testing for the chemicals and approval of compost sales.

The Lewiston-Auburn Water Pollution Control Authority, like many treatment facilities, had levels of at least one type of per- and polyfluoroalkyl (PFAS) substance high enough to merit additional state testing in 2019. The issue has led to higher costs for disposing of sewage sludge and has delayed reopening Auburn’s compost facility.

PFAS were used for decades in nonstick cookware and firefighting foam, among other things, and have since been linked to cancer, thyroid disruption and reproductive and immunological changes in lab animals.

According to Travis Peaslee, interim superintendent of LAWPCA, even with City Council and Planning Board approval at the local level, it’s still “unlikely that we will operate in the near future,” due to “staffing, infrastructure needs, and regulatory uncertainty.”

Peaslee said the state is only granting approval of compost sales on a year-to-year basis while they continue testing, and without more certainty, the LAWPCA board is “not comfortable investing funds into the operation.”

“When (and) if PFAS regulations become clearer the board will reassess the operation,” he said.

In order to eventually reopen, the compost facility at Penley Corner Road had to conduct a pilot project to prove that it could be successful using only “anaerobically digested solids” from the LAWPCA plant and without an odor control system. Prior to its closure, the facility used what’s known as a “biofilter” to control odors, which led to the nitrate groundwater contamination, Peaslee said.

The LAWPCA plant uses an anaerobic digestion system — a process in which microorganisms break down material, which Peaslee said significantly reduces the “volatile component of material” and its odor. Because the facility would only be using material produced at the LAWPCA plant, its overall volume would be reduced.

After running the successful pilot project between September 2019 and January 2020, as well as a “professional odor evaluation,” LAWPCA received approval in June. The compost produced during the pilot project was sold with the current levels of PFAS, with approval by the Maine Department of Environmental Protection.

The facility sold the compost to the general public until its closure in 2018. Peaslee said everything produced during the pilot was sold to “a handful of contractors.”

But, Peaslee said, the uncertainty surrounding PFAS regulations is still clouding the future.

In the meantime, he said, “We still want all approvals in place and plan to keep the facility operational-ready in case situations change.”

Treated sewage sludge, also known as “biosolids,” has been commonly used on farms as fertilizer or distributed as compost. Composting the material is also more cost effective for municipalities than sending it to landfills.

According to a 2019 memo created for the Lewiston City Council, the tipping fee for landfilling the material is $60 per ton, plus transportation costs. The memo said composting ranges between $40 and $50 per ton, and that sending material to farms for land application is the least expensive option, at $17 per ton.

In order for treatment facilities that have tested above PFAS screening levels to continue land applications, the DEP is requiring additional testing at sites where sludge has been spread.

During initial testing in 2019, LAWPCA tested 14 hayfields within its land application program, and only two were below screening levels and could accept biosolids.

Peaslee said Wednesday that additional testing has allowed LAWPCA to conduct about 2,100 yards worth of land applications. The plant produces about 8,300 yards annually, he said. The remaining material is transferred to a landfill.

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