CADILLAC — Investigators in Michigan and elsewhere find low-level contamination of “forever chemicals” virtually everywhere, but the state says it can’t always afford to figure out exactly how the chemicals get into the environment.
Take Cadillac, where the Michigan PFAS Action Response Team, or MPART, started an investigation in 2024 after PFAS — per- and polyfluoroalkyl substances — were found in a private well at levels slightly above Michigan's standard for safe consumption. Subsequent testing in the area has shown the presence of PFAS in many private wells at similarly low levels.
At this point, MPART is still testing to determine if a risk to human health exists from drinking groundwater in the area, but locating a source is no longer a priority, making Cadillac one of 38 so-called “orphan” PFAS sites around the state.
Without a source, investigators can’t define the boundaries of the contamination, including how far out or down the plume goes in the ground or whether it migrated from surface waters or through groundwater, MPART Executive Director Abigail Hendershott said.
Identified culprits can also be made to pay for cleanup.
Hendershott said that, as of fiscal 2023, the state had spent about $125 million investigating PFAS contamination and mitigating its potential harm statewide. Testing all private wells in Michigan — an idea proposed by some environmental advocates — would cost around $600 million.
"That number gets pretty big pretty quick," Hendershott said.
In Cadillac, investigative costs would have run in the hundreds of thousands of dollars if not for the fact that many residents decided to obtain their own test kits through companies such as Cyclopure.
Hendershott recommends homeowners throughout the state test their water, even if they're not in an area of known contamination. The MPART website includes resources related to self-testing methods for private well owners.
"It's still good for homeowners to take that precautionary step," Hendershott said.
Prolonged exposure to PFAS — primarily through consumption of contaminated water — can lead to a host of health problems, including liver and kidney damage, thyroid disease, cancer, hormonal changes and developmental delays in children.
Hendershott said her agency doesn’t have a certain dollar figure at which it decides to pull the plug on a source investigation. Rather, it depends on the data they’re able to collect and whether that data points investigators in a direction worth pursuing.
In some cases, Hendershott said, they simply run out of wells to test and don’t know where to take the investigation next.
"We could end up spending a lot of money and not find any huge variations (in contamination)," Hendershott said, comparing MPART to a triage nurse who prioritizes care based on the severity of illness or injury.
‘PFAS is circling the globe’
Hendershott said most investigations her office has initiated have located a single source or handful of sources contributing to contamination.
Such investigations are fairly straightforward because the concentrations of PFAS typically are very high (sometimes in thousands of parts per trillion) and they tend to decrease the farther away testing is done from the initial source. That’s the case at the former Wurtsmith Air Force Base in Iosco County, where PFAS concentrations were found to be thousands of times above what experts consider safe to drink.
Other investigations aren't so straightforward because contaminant concentrations are relatively low (in the single- or double-digit parts per trillion) and can't be tracked to a large source in the same way.
Michigan considers PFAS in drinking water unsafe at between 4 and 16 parts per trillion for the compounds considered the most dangerous, including PFOA, PFOS and PFNA.
Sometimes the clues lead away from an initial suspect.
Take Clare County’s Lake George, where a water sample taken from a laundromat showed PFAS levels higher than the state drinking water standard.
Most of the nearby wells where contamination was found, however, were "upgradient" of the laundromat — meaning the groundwater doesn't flow in that direction — leading investigators to conclude the contamination at those locations was coming from somewhere else.
"We're finding that Cadillac is not unique," Hendershott said. "PFAS is circling the globe."
More testing could provide additional insight into where low-level PFAS in the groundwater are coming from, but a more immediate question for agencies like MPART and the Michigan Department of Environment, Great Lakes and Energy is how to pay for it.
MPART tested about 400 wells at the Hillsboro Avenue Area of Interest near Grand Rapids, where PFAS has been detected in private drinking water wells slightly above state standards.
After spending around $360,000 on testing, Hendershott said, they still have not located a single large source of contamination.
A theory
One theory under consideration by MPART is that some of the PFAS contamination in Michigan is caused by private septic systems.
Studies conducted in other states, including New Hampshire and New York, have shown a connection between groundwater contamination and products flushed into private septic systems, including shampoos, detergents, carpet cleaners, medications, cosmetics, and even toothpaste and toilet paper.
The studies also determined that the amount of PFAS flushed from one domestic septic system to the next can vary dramatically depending on differences in consumer behaviors and the types of products used.
A community with a lot of residents who take pharmaceutical drugs — such as a nursing home — might flush more PFAS into a septic system than a neighborhood containing mostly young, healthy people.
"When we say domestic, we tend to think residential," Hendershott said, "but it could also be businesses."
Schools are another potential source of domestic contamination, since they often use copious amounts of cleaning chemicals — many containing PFAS. MPART officials have said contamination found near the Wexford-Missaukee Career Technical Center outside Cadillac may be an example.
To help researchers tell if contamination is linked to a domestic source, they look for other compounds besides PFAS in the samples.
Researchers in New York and New Hampshire tested for artificial sweeteners because they are not natural in the environment, don't break down easily and are found in predictable levels in many domestic septic systems, since they are contained within food and beverage products. If sweeteners and PFAS are in the same place, the culprit could be domestic.
But that might not be as effective in an area where a wastewater treatment plant is nearby, such as Cadillac.
MPART PFAS Specialist Mike Jury said treatment plants don't filter out artificial sweeteners, so to rule out a treatment plant as a source of PFAS contamination, they'd have to track a different compound.
An overlooked suspect?
A theory proposed by environmental activists in Cadillac is that contamination entered the groundwater aquifer via the Clam River, where the Cadillac Wastewater Treatment Plant has for decades discharged PFAS.
The amount of PFAS discharged into the river has been within state and federal standards for treated wastewater effluent, but clean water advocates argue the plant still could have contaminated water sources downstream.
MPART officials have not been able to prove or disprove that theory, in part because of the complexity of identifying a single source when contamination levels are so low.
Laboratory analyses of some of the samples taken in the Cadillac industrial park show a seemingly random mixture of PFAS contaminants at varying levels of concentration. If the contaminants were coming from the same source or handful of sources, the level of contamination and mixture of compounds likely would be similar, Hendershott, the MPART chief, said.
Eliminating the source
Given the scope and complexity of the problem, Hendershott said she believes limiting the use of PFAS in commercial products and industrial processes will be the next step taken in Michigan to remove them from the environment.
A few years ago, several bills in the Legislature would have established a statewide septic code but were not taken up for a vote before the end of the 2024 lame duck session. Michigan remains the only state in the US without a unified septic code.
Democratic state Rep. Phil Skaggs of East Grand Rapids, who sponsored two septic bills, said the legislation had wide support from the environmental community and state environmental regulators.
Skaggs said a vote on the bills was supposed to have occurred the night the 2024 session ended but didn’t because of legislative boycotting that prevented the state House from having a quorum.
Skaggs said the bills drew some pushback from Republican lawmakers who opposed a provision that allowed state health officials to go into homes to inspect private septic systems.
“People have to balance whether the problem outweighs the solution,” Skaggs said. “Water does not know where the property line is and no one has the right to pollute their neighbor.”
Skaggs said he doesn’t believe the legislation would get far in the current House but hopes to reintroduce it in the coming years.
Hendershott said the legislation would have been "very beneficial" to the state, as it would have required outdated septic systems to be replaced.
That is relevant in the discussion around PFAS, Hendershott said, especially in neighborhoods situated around lakes where homes have their own septic systems that were installed years ago and not designed for full-time, year-round use.
Hendershott said that, generally speaking, PFAS entering the groundwater through home septic systems around a lake wouldn't cause extreme contamination in the surface waters but it would bioaccumulate in fish and show up in lake foam in high concentrations.
No studies have been conducted to determine if there is a link between private septic systems around lakes and the presence of PFAS in fish tissue.
As for the link between groundwater contamination and domestic septic systems, Hendershott said her agency has contemplated the pros and cons of conducting a statewide study similar to the ones done in New York, Massachusetts, New Hampshire and elsewhere, but no decision has been made yet.
This reporting is made possible by the Northern Michigan Journalism Collaborative, led by Bridge Michigan and Interlochen Public Radio, and funded by Press Forward Northern Michigan.
