PFAS contaminates groundwater, sewage sludge in Metro Detroit. Should we be alarmed?

State regulators have shown little concern for astronomical PFAS measurements in local groundwater and sewage effluent. Activists see it differently.

In August of 2018, a video captured a geyser of frothy bubbles pouring out of a manhole and flowing onto the roadway for several days on Schaefer Highway near I-75 — perhaps the first “foam event” to be documented on media in Metro Detroit.

“I was frustrated because there were citizens— people that didn’t know what they were dealing with— running around, chasing this foam and touching it,” Denise Trabbic-Pointer, a chemist who serves as a technical consultant for the Michigan Chapter of the Sierra Club, told Planet Detroit.

Tests from the drainage ditch where the foam spilled out showed the presence of PFOS and PFOA, two common forms of the so-called “forever chemicals” that have been implicated in low infant birth weights and an increased risk of kidney and testicular cancer, among other things.  Several years later, the foam was traced back to the nearby Marathon refinery, where the company used PFAS-laden foam called class B Aqueous Film Forming Foam (AFFF) for emergency response and fire-training, beginning in the 1980s and continuing to 2018.

One groundwater test at the Marathon property showed PFOS at 765,000 parts per trillion (ppt). And while that number may seem small, it means the groundwater below Marathon is 10,000 times higher than the state’s cleanup criteria of 70 ppt for PFOS in groundwater. Current Michigan standards for drinking water are eight ppt for PFOA and 16 ppt for PFOS, although experts warn that even one ppt could cause negative health impacts.

“I’m concerned about any PFAS in the water at all,” said Theresa Landrum, an environmental activist in southwest Detroit who serves on the citizen’s advisory workgroup for the Michigan PFAS Action Response Team (MPART). Landrum said she’s especially worried about PFAS because, “it gets into the body, it latches on. And more PFAS comes in and latches on and builds up over time.”

Trabbic-Pointer says that being able to trace where the foam came from is a “big deal”, but this doesn’t mean that the situation at Marathon is under control. “They’re just now in the investigation phase,” she said. “It’s still going to migrate for a while. They haven’t even started the cleanup.” The company will be submitting a feasibility study on cleanup and remediation in December. 

The event on Schaefer Highway shows that in addition to problems with air pollution, southwest Detroit and Downriver communities like Melvindale and Wyandotte face issues with PFAS contamination in soil and groundwater. 

And these chemicals— which persist in the environment, travel easily, and can build up in human bodies— have likely already made their way into the Rouge and Detroit River and potentially to drinking water intakes downstream. PFAS has also been confirmed at high levels in the ‘biosolids’ — or dried human waste — that are processed in southwest Detroit and used as fertilizer on farms in the U.S. (including in Michigan) and in Canada.

How worried should we be about PFAS in our biosolids?

Drinking and surface water tests in the area around Marathon have mostly shown relatively low levels of PFAS contamination. Michigan’s Department of Environment, Great Lakes and Energy’s (EGLE) hosted a recent public meeting and presented surface water results around the refinery that ranged from 1.3 ppt to 10.8 ppt for PFOS, well below the standards for cleanup. 

However, the 765,000 ppt groundwater sample at the Marathon refinery puts the facility in the same ballpark as certain military bases, which are generally regarded as some of the nation’s most contaminated PFAS sites on account of years of AFFF use. Like Marathon, these installations often have groundwater PFAS levels exceeding 100,000 ppt.

Still, one advantage that southeast Michigan has over some other areas hit by high PFAS levels is that most citizens aren’t using well water, but rather municipal sources with intakes on the Detroit River.

“We’re really lucky here in Southeast Michigan that we’re using Great Lakes water as our source of drinking water, it’s not particularly vulnerable to environmental contamination,” Tracy Kecskemeti, Materials Management Division supervisor for EGLE said during a public meeting on September 15, 2020. 

Yet, the downside of having contamination in rivers, lakes, and groundwater is that it provides ample opportunity for these pollutants to move through the environment, something that PFAS is remarkably good at doing.

“The unique thing about PFAS is that not only is it very persistent, but it also travels into our drinking water,” Courtney Carignan, a PFAS researcher at Michigan State University told Planet Detroit. “(PFAS is) different from other persistent organic pollutants that we historically have worked with that would get tied up in the sediments or the soils.” 

And that ability to travel gives it an easier pathway into food by way of biosolids — especially concerning since the storm sewers where the Schaefer incident occurred go to the Great Lakes Water Authority’s (GLWA) wastewater treatment plant in southwest Detroit. The plant then sends its sewage sludge to the neighboring NEFCO biosolids dryer. This facility is the largest of its kind in North America, producing 420 tons of dried biosolids a day since 2015, which are sold to farmers and used to grow food. 

“The wastewater treatment plant isn’t going to take any of it out,” Trabbic-Pointer says of the potential for PFAS to move into biosolids.

A June EGLE report found that the effluent from the GLWA facility measured 30 ppt for PFOS, the highest level of any of the wastewater treatment plants listed in the report. Tests provided to Planet Detroit by EGLE from November, 16, 2018 show biosolids from the NEFCO facility with concentrations of 9,400 ppt for PFOS and 1120 ppt for PFOA.

From the processing facility, this PFAS-laden sludge goes into a product that will then be broadcast onto Michigan farm fields as fertilizer, potentially spreading the problem across the region. Trabbic-Pointer says quite a bit of this material is being used in the metro area. And the MiWaters website lists a number of biosolids application sites around Detroit.

Biosolid contamination is potentially problematic because of the tendency of PFAS to bioaccumulate in animals and humans, where the concentration of chemicals increases over time. And research shows that PFAS can move from biosolids into crops, livestock, and human bodies. 

There is also evidence that PFAS biomagnifies, meaning its concentration increases as the chemicals move up the food chain. In Maine, two dairy farms have shuttered because of issues with PFAS contamination. The state of Maine determined that biosolids were at fault for at least one of these, with milk showing levels as high as 1,420 ppt

For now, EGLE and GLWA don’t appear overly concerned with this issue. In a Metro Times article, Scott Dean, a spokesman for EGLE, said that biosolids were unlikely to threaten food or water on account of the relatively small volume of fertilizer being applied over large fields. And Navid Mehram, COO of Wastewater Operating Services for GLWA, said the levels of PFAS in biosolids “are not much different from levels ​that exist in food waste, compost or septic systems.”

Trabbic-Pointer is less sanguine about the threat from biosolids. She emphasized that the level of contamination would depend on application rates, but added, “after they are land-applied as pellets or injected as liquid–as are most biosolids from wastewater treatment biosolids–they do and will mix back into surface waters and groundwater fairly readily.”

Drinking water concerns in Wyandotte

At the public meeting in September, EGLE addressed drinking water tests for Wyandotte’s municipal water system from August 2019, which found total PFAS levels of 55 ppt in raw water and 30 ppt in treated water. (The levels of PFOA or PFOS in treated water was 26 ppt, 10 points higher than what’s allowable for PFOS, and 18 points above the PFOA threshold, although these standards were not in place at the time of the testing.) 

These numbers are nowhere near as high as some of the worst in the state­— like the drinking water in Parchment, MI, that had PFAS at 1,828 ppt in treated water — but the unknown source of the contamination is troubling.  Wyandotte is downstream from sites like Marathon — which sits on the Rouge River near its junction with the Detroit River — raising concerns about chemicals migrating from that site or elsewhere.

Wyandotte water department superintendent Bill Weirach speculated that the high PFAS tests may have been caused by the use of Teflon tape on a section of pipe near where water samples were taken, but officials were not able to rule out the river as a source. Another potential contamination source has emerged at the BASF chemical manufacturing facility on the Detroit River, upstream from the water intake. On December 6, 2018, an outfall from this plant that drained into the river showed the presence of PFOS at 56 ppt.  But the highest recent readings from the facility were from the summer of 2020 — a year after the high drinking water tests — when groundwater tests showed PFOS at 8,070 ppt and PFHxS at 762 ppt. Since Michigan only began testing for PFAS in drinking water in 2018, it’s possible that chemicals from BASF, Marathon, or elsewhere may have been making their way into the municipal water supply for years, undetected.

Christy McGillivray, an organizer with the Sierra Club raised the possibility that other measures like blood-testing may be necessary to determine exposure.

“The burden of proof is literally on our bodies,” McGillivray said. Although Michigan’s new PFAS standards for groundwater and drinking water are among the most aggressive in the nation, they only cover a handful of chemicals, while thousands of classes of PFAS are still being manufactured. 

With the difficulty of establishing direct links between various illnesses and the chemicals that may be causing them, McGillivray argues that it’s time to move from environmental policies that require evidence of harm towards the “precautionary principle”, placing the burden of proof on manufacturers to establish that chemicals are safe before they can be used.  

Michigan has taken some action towards limiting PFAS use in the state, collecting 30,000 gallons of class B AFFF firefighting foam from municipalities and fire departments  and adding PFAS sampling to its permitting requirements under the National Discharge Pollution Elimination System, which regulates the discharge from industry and municipalities going into waterways. This move could reduce the amount of PFAS entering wastewater treatment plants and thus ending up in biosolids.

But with people’s bodies effectively being used as PFAS measuring devices, McGillivray believes the time has come to take a different approach to handling the chemicals. 

“What testing numbers show us from a big-picture perspective is that we have to get PFAS off the market,” she said. “We have to regulate PFAS as a class of chemicals and not regulate them on a one-by-one basis.”


Our reporting 

runs deep.

Get the latest local enviro news in your inbox with Planet Detroit.

Scroll to Top