Houghton County and the state are conducting testing at the site of the former Peterson-Lahti landfill to determine the level of PFAS found at wells on the landfill, as well as on neighboring properties. Garrett Neese/Daily Mining Gazette

HOUGHTON — Houghton County is looking to see what remedies might be needed after PFAS contamination was detected at a former landfill site in Portage Township.

The former Peterson-Lahti Landfill operated from 1988 to 1995, before modern safety standards went into effect. As a Type III landfill, it accepted construction material, and so “was neither required nor encouraged to be lined,” said Commissioner Glenn Anderson. The per- and polyfluoroalkyl substances, or PFAS, are believed to have arrived through carpeting from demolished housing.

The original owner abandoned the property, which reverted to the county in 2011.

“It’s never been capped, it’s never been closed,” said county Administrator Ben Larson. “So now we’ve got a Type III landfill that is unlined, that’s possibly leaching PFAS into the groundwater, the neighbors. So now we’ve got something staring us in the face.”

EGLE requested sampling at groundwater monitoring wells because of the potential for PFAS contamination.

The man-made, long-lasting chemicals can accumulate in humans, other animals and the environment. They have been linked to higher likelihoods of health problems, including some cancers and developmental delays.

As PFAS became a major issue at the state level, the state sorted its landfills by priority levels, said James Staley, an engineer with the Department of Environment, Great Lakes and Energy’s materials management division.

Peterson-Lahti straddled the high and medium priorities. Groundwater at the site was impacted, but it hasn’t been established if those impacts extended to the wells at neighboring properties.

“There’s no immediate downgrading as far as the groundwater flow goes, but the landfill was also never really properly capped,” Staley said. “The previous owners sort of walked away. For that reason, we put it on a fast track to get the groundwater looked at.”

In March, Houghton County conducted sampling at four wells on the site, two of which had PFAS levels above state criteria.

According to a state webpage about the landfill site, the highest well had 27 parts per trillion (ppt) of perfluorooctanoic acid (PFOA), compared to 8 ppt; 19 ppt perfluorooctyl sulfonate (PFOS), compared to 16 ppt; and 68 ppt perfluorohexane sulfonate (PFHxS), compared to 51 ppt.

“We’ve seen much higher concentrations of PFAS in the state, but they are over criteria, so we’re going to continue to look at it,” Staley said.

No wells are due east of the landfill, the direction in which the groundwater flows, Staley said. There are some wells north of the landfill. Those are being sampled “out of an abundance of caution,” Staley said.

EGLE plans to run additional tests on the site, while Another company is conducting tests to make sure no PFAS from the landfill is leaching into groundwater and neighboring properties.

“The bottom line is the public should be informed and aware that we’re running towards this and not running away from it, and we’ll work closely with EGLE and other authorities to make sure,” said Board Chair Tom Tikkanen.

The landfill comes within 800 feet of the Pilgrim River, which acts as a hydraulic barrier, Staley said. At this point, the PFAS concentrations in the wells are low enough that EGLE doesn’t anticipate sampling the river, Staley said.

He plans to resample the wells himself either in October or next May. He’s looking to corroborate what the county consultants found and also get a sense of if the concentrations change over time.

PFAS “love surfaces,” he said. Because the well had been undisturbed for so long, the well casing may have preserved an unrepresentative amount.

“The fact that there’s standing water in that has the potential that the PFAS results may be abnormally high,” Staley said. “That’s one reason to go back, is the more water you bail out of there, you get a cleaner slug of water to sample.”

Staley said the most likely outcome would involve ongoing monitoring. That would depend on what the next round of testing finds, as well as the samples from residential wells.

“If it’s not detected, then likely moving forward it would be some form of continued routine sampling and monitoring to keep an eye on the concentrations, make sure they’re not going up,” he said.