OSCODA, Mich. -- Democrat U.S. Sen. Gary Peters is criticizing the U.S. Air Force for taking an "aggressive and defensive posture" with the state of Michigan related to toxic contamination cleanup at a former base in northern Michigan.

In a Jan. 31 letter, Peters invited Air Force Secretary Heather Wilson visit the community of Osocda, where PFAS chemicals coming from the former Wurtsmith Air Force Base are contaminating drinking water wells, lakes, a river and causing toxic lake foam buildup.

The letter follows an MLive report that the Air Force was refusing to comply with state regulations that limits the amount of PFOS, a well-known compound within the PFAS family of contaminants, to 12 parts per trillion (ppt) in groundwater entering surface water bodies.

Following a Michigan Department of Environmental Quality violation notice, the Air Force in December told the state it would not take any new actions to stem the flow of contamination that is entering a wetland called Clark's Marsh near the former base.

The Air Force said it did not have to comply with the state regulation because of the federal government's sovereign immunity from state or local laws.

Peters, the ranking Democrat on the Senate homeland security and government affairs committee, expressed concern that the Air Force was "not working in good faith" with the state and said that Congress waived federal sovereign immunity for environmental cleanups.

Peters referenced a meeting with Air Force assistant secretary John Henderson, in which Henderson allegedly said the Air Force would be "proactive in its approach, consistent with federal law rather than waiting an interagency approach or judicial process to mandate remedial action."

"This aggressive and defensive posture amidst the ongoing dispute resolution process with the state is unproductive at best, and it concerns me that so little has been accomplished since PFAS was confirmed at Wurtsmith in 2010," Peters wrote.

"The Air Force's refusal to meet the state of Michigan's water quality standards only serves to reinforce my sense that Congress must move swiftly to direct the Environmental Protection Agency to establish enforceable and protective federal standards."

Reference to the lack of EPA standards follows a report this week in Politico that the agency would not be establishing a maximum contaminant level for compounds PFOS and PFOA under the Safe Drinking Water Act, angering environmental groups and many states, which want the federal government to set enforceable drinking water standards for PFAS chemicals.

The EPA did not outright deny the report, but responded by saying its forthcoming national PFAS management plan was still being finalized. Politico reported that the plan does include classifying PFOS and PFOA as hazardous under federal Superfund law, which would give the EPA authority to direct cleanups at sites where the contaminates are found.

There's been mounting pressure on the EPA from Congress to act on PFAS contamination. A bipartisan group of lawmakers this month formed a PFAS Task Force co-chaired by Rep. Dan Kildee, D-Flint, to help educate peer lawmakers about the chemicals, draft legislation, meet with affected communities and fight for more cleanup funding.

Kildee is inviting a PFAS activist from Oscoda, Cathy Wusterbarth of the group NOW (Need Our Water), to attend the Feb. 5. State of the Union Address.

Michigan is one of several state dealing with PFAS contamination in surface water and groundwater used for drinking. The chemicals are used by multiple industries and are in Class B firefighting foam, which the military used heavily for decades.

The chemical properties that make PFAS valuable in the marketplace also make them persistent and bioaccumulative in the environment. Exposure to them are linked to chronic health conditions like cancer and developmental delays in children.

On Thursday, Jan. 31, the Air Force responded to a Jan. 24 MLive request for comment about its refusal to follow state surface water quality regulations.

The Air Force sent a statement reiterating its position on the DEQ violation and said that "although the Air Force will not be taking any new actions in response to the violation notice, we will continue to work with MDEQ to address many of the issues raised therein."

The Air Force said the groundwater treatment system installed at the former fire training area where PFAS foam use has heavily contaminated the groundwater is working better than expected and has greatly reduced the PFAS contamination entering the marsh.

The DEQ says groundwater under the marsh has tested at 42,000-ppt and surface water in the marsh has tested at 1,400-ppt. The state's surface water limit for PFOS is 12-ppt.

The Air Force plume map distributed with its remarks show that PFOS in the groundwater entering the marsh tested at 3,710-ppt last year, a marked decrease from several years ago.

The state wants the Air Force to increase the amount of groundwater being treated and the size of a capture zone for the treatment system.

This article is written by Garret Ellison from MLive.com, Walker, Mich. and was legally licensed via the Tribune Content Agency through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.