Schuette declined to comment about his actions regarding the lawsuit request. Bridge Magazine obtained a Dec. 18, 2018, letter he sent to Snyder five months after the governor’s request that blames the inaction on Snyder’s former environmental chief, Heidi Grether.

Schuette wrote that Grether never approved a suit nor provided “the factual, technical and scientific support for any legal action.”

“My attorneys have been providing legal support whenever it was requested, and in that time have dedicated thousands of hours working on PFAS-related issues,” Schuette wrote in the letter 13 days before his term ended as attorney general.

Grether told Bridge the explanation is “pretty bogus.” She accused him of a “stonewall” and “playing it safe” to protect his campaign for governor and avoid actions that might upset political allies.

“I was unaware that the governor's letter was not a sufficient request,” Grether said. “I didn’t know I held more sway than the governor.

Grether said her agency met with Schuette’s office countless times about a potential lawsuit against 3M — even before Snyder requested that Schuette take action. The Department of Environmental Quality continually provided Schuette’s office with information when asked, she said, but the agency could not force 3M to disclose valuable information for building a legal case; it lacked the legal tools Schuette had.

Rusty Hills, a former top aide to Schuette, bristled at the accusation that politics influenced any decisions.

“That never played a role, and I was in the meetings — so I can I can vouch for that,” he told Bridge.

“We launched massive investigations against large, powerful organizations and individuals — Michigan State University, the Catholic Church. We investigated the Snyder administration (for the Flint water crisis) for goodness’ sake.”

Hills noted that the attorney general division chief who drafted Schuette’s letter to Snyder, Peter Manning, still works for Nessel.

The back-and-forth comes as Michigan, after years of delays, is ramping up its response to PFAS chemicals.

Formally called perfluoroalkyl and polyfluoroalkyl substances, PFAS are a class of non-stick, waterproof and stain-resistant compounds that also serve as fire retardants. Such chemicals may have been used at as many as 11,300 Michigan fire stations, landfills, industrial sites, military bases, airports and other locations, according to state estimates.

Research has linked PFAS compounds to developmental and behavioral problems for infants and children, hormonal and immunity problems as well as certain cancers.

Michigan is now monitoring PFAS-contaminated groundwater at 67 sites in 34 counties. Testing data show at least trace amounts of PFAS in more than 100 public water systems.

In his 2018 letter instructing Schuette to sue, Snyder wrote that PFAS in Michigan’s waters “are directly attributable to the products 3M designed, manufactured, marketed and sold since the 1960s,” including Scotchgard and firefighting foams known as AFFF and AR-AFFF.

“It is generally understood that 3M was aware of the nature of its products and the threats they posed to public health,” Snyder wrote.

“Despite this knowledge, 3M continued to manufacture, market and sell its products containing the contaminant without disclosing to its customers and regulatory agencies the threat they posed to the general public.”

The company denies the allegations.

“3M acted responsibly in connection with products containing PFAS and stands behind its record of environmental stewardship,” spokeswoman Fanna Haile-Selassie told Bridge in a statement.

A 3M web page touts the benefits of PFAS, calling the compounds “critical to the manufacture of electronic devices such as cellphones, tablets and semiconductors.”