LANSING, MI — Scientific and legal experts say legislation pending in Michigan would double an existing safety threshold for toxic PFAS chemicals in drinking water, hamper the state’s ability to rely on new toxicity science and create loopholes in state law to grandfather potentially weakened standards into future cleanups.

Senate Bill 1244, sponsored by a Sen. Jim Stamas, R-Midland, passed the Michigan Senate on Dec. 4. It’s expected to be brought to the state House floor sometime this week.

“This legislation would significantly increase the amount of PFAS in water that people could legally be exposed to,” said Richard DeGrandchamp, a University of Colorado toxicology professor who co-authored a controversial Michigan Department of Environmental Quality report six years ago that warned of widespread PFAS pollution.

The bill is one of many flying through the state legislature during a lame duck session drawing national attention for blatant attempts by Republicans to strip power from elected Democrats before they take over as secretary of state, attorney general and governor.

It is among several that weaken or limit the purview of state environmental regulators; passage of which are believed to be central to negotiations around getting Republican legislative support for Gov. Rick Snyder’s plan to raise millions for polluted site cleanups by hiking the “tipping fee” imposed on landfilling waste in Michigan.

Environmental and public health advocates say SB 1244 would hamstring the state’s ability to use new toxicology when setting standards that govern toxic cleanups. The Michigan Chamber of Commerce is pushing the legislation, arguing that updated pollution cleanup rules are long overdue and the bill is necessary to spur redevelopment at contaminated sites.

The state has, for years, been going through more than 300 toxic chemicals to update cleanup standards based on advancements in scientific understanding of the risk posed by exposure. The standards are a controlling factor in toxic cleanups that, among other things, dictate which sites are considered contaminated, how polluters tackle a cleanup, and how much work they end up doing.

The legislation amends Part 201 of the state Natural Resources and Environmental Protection Act — the legal framework on which Michigan cleanups are built. The bill isn’t specific to PFAS, but it binds state standards to a federal database that doesn’t include PFAS values and limits the studies that DEQ could otherwise use, throwing existing rules into confusion at a time when scrutiny on the chemicals is intensifying and more contamination is being found.

The DEQ has found the chemicals at some level in municipal water serving almost 2 million people in Michigan already.

Because of ambiguity around the status of PFAS as hazardous substances at the federal level, there’s concern both a state surface water standard passed in 2014 and new potable groundwater standard developed earlier this year would be ensnared in changes drafted by pro-industry groups hoping to gain more favorable cleanup laws.

Jason Geer, director of energy and environment policy at the Michigan Chamber, said industry experts involved in drafting the bill don’t believe the proposed changes would affect state PFAS regulations, but the chamber is open to amending the bill to clarify that.

“We’re open to clarification to ensure that concern is dealt with,” Geer said.

Amendments would require the Senate to vote on the bill again. It must pass both chambers in identical form before moving to the governor.

The DEQ has refused to discuss the bill in its current form. Messages to spokespeople at the DEQ were not immediately returned.

Stamas, the bill sponsor, also did not return a message on Monday.

DeGrandchamp, a recognized expert in court who served on the U.S. Department of Justice expert witness unit for two decades, calculated that SB 1244 would effectively double the allowable PFOS and PFOA levels in Michigan groundwater used for drinking purposes from 70 parts per trillion (ppt) combined to 146-ppt apiece.

As written, the bill would prohibit those two individual PFAS compounds from being considered together in samples as they are now, he said. That means groundwater could have up to 292-ppt of PFOS and PFOA combined before the DEQ could require a polluter take action.

In January, the DEQ set 70-ppt combined as the state’s groundwater standard based on the Environmental Protection Agency’s non-enforceable health advisory level. Since then, the state has used the standard to, among other things, sue polluters like Wolverine World Wide and make emergency decisions about who gets bottled water in contaminated areas.

DeGrandchamp’s calculation is based on language that would force DEQ to calculate standards based on current toxicity values used by the EPA and the Agency for Toxic Substances and Disease Registry (ATSDR). Those values, used in risk assessment at contaminated sites, describe in numerical terms the health effects expected from different levels of exposure, or dosage, to a toxic chemical.

The EPA toxicity values for PFOS and PFOA were set in 2016 and used to develop the agency’s health advisory level of 70-ppt for exposure in drinking water. The ATSDR has more recent values, posted June 20 in a draft report that gained widespread attention after Trump Administration officials tried to block its release, fearing the lower numbers would spark a “public relations nightmare.”

The levels are much lower. For childhood exposure, the new ATSDR values translate to 21-ppt for PFOA and 14-ppt for PFOS when converted into drinking water concentrations. But the new numbers couldn’t be used to set PFAS standards because they’re still in draft form and the bill requires DEQ use “final” values to set cleanup standards.

“This is really problematic for protecting public health,” DeGrandchamp said. “Right now, the scientific community is in flux regarding what levels are safe to be exposed to in drinking water. With each new study, these compounds appear to be more toxic than we thought the day before.”

The latest example came last month, when a new study published in the Journal of Clinical Endocrinology and Metabolism linked exposure among young men living in a contaminated area of Italy with shorter penises and lower sperm counts. Exposure to PFOS and PFOA have already been linked by U.S. human studies to problems like reduced immune function, obesity, kidney cancer, testicular cancer and increased cholesterol levels.

Regulations targeting PFAS in groundwater aren’t the only concern. Michigan’s surface water quality standard of 12-ppt for PFOS, set low to account for biomagnification in fish, could be at risk, too.

The DEQ is applying that law to contamination at military sites like the former Wurtsmith Air Force Base in Oscoda and wastewater treatment plants discharging high levels from auto parts manufacturing waste.

A.J. Birkbeck, an environmental attorney in Grand Rapids who helped a Rockford citizen group expose the Wolverine World Wide contamination in Kent County, said the bill as written might eliminate the 12-ppt standard “possibly in a matter of months.”

“The bill actually says that criteria such as the PFAS surface water standards are “not legally enforceable” until the DEQ formally enacts them,” said Birkbeck. Doing so would be lengthy process made more complex by a pair of new governor-appointed review panels with the power to veto proposed DEQ rules and overturn permitting decisions.

John Dulmes with the Michigan Chemistry Council, which is supporting the bill, argued that the surface water quality standard would not be affected because its codified in a different section of state law.

Birkbeck and DeGrandchamp both noted that another provision in the bill would let polluters grandfather a weaker standard into future cleanup work by submitting paperwork prior to passage of tougher rules.

“All a company needs to do is file a work plan with DEQ before the effective date of a new standard and they get a free pass to investigate and cleanup to the old, less protective standard,” said Birkbeck.

With toxicology around PFAS in flux, DeGrandchamp said grandfathering less protective cleanup standards is another move that would keep the DEQ from using the best science available.

“If we find out that these compounds are more toxic than we know now, we’ll have no recourse to adjust what the cleanup levels should be,” he said. “That’s a real problem. Science moves forward but not at the speed sometimes that we would like.”