This article was written as part of The Michigan Daily’s investigation to better understand the risks, advancements and future of water in Michigan and beyond. Read other stories from the project here.
The Gelman plume, an underground contaminated mass of water, has been spreading 1,4-dioxane, a possible human carcinogenic, into the groundwater of Scio Township and Ann Arbor since the 1960s. Although the Ann Arbor community has known about the plume since the 1980s, the site has only recently been put forward to be seriously considered for the Environmental Protection Agency’s list of the most severe contamination releases in the US.
In 1958, Charles Gelman, a U-M student, founded Gelman Sciences, Inc., a manufacturer of water and air pollution detection filters. Gelman Sciences used an estimated 850,000 lbs of 1,4-dioxane in its manufacturing process from 1966 to 1986 and polluted the soil and groundwater near the factory, located on South Wagner Road in Scio Township.
In 2021, the Michigan Department of Environment, Great Lakes, and Energy sent a letter to theEPA, requesting that the EPA reinitiate assessment of the Gelman plume for the National Priorities List, a list that contains the United States’ most serious uncontrolled or abandoned contamination sites. In March 2024, the EPA proposed the site for the Superfund program, which gives EPA the funds and authority for contamination clean-ups. As of December 2024, the EPA was in the process of assessing the responses they received in the 60-day public comment period and a decision has yet to be reached. The subsequent development of a clean-up plan can take more than a decade.
In an email to The Michigan Daily, Danielle Kaufman, EPA public affairs specialist, wrote that the EPA’s plans for addressing the contamination will be developed once the site is added to the NPL, but there have been no new updates to the process since December 2024.
“Plans for investigating and mitigating 1,4-dioxane impacts will be developed as part of the Remedial Investigation/Feasibility Study (RI/FS) process, which will begin after the site is finalized to the National Priorities List (NPL),” Kaufman wrote.
Rita Loch-Caruso, professor emerita of toxicology and Program in the Environment, told The Daily in an interview she was initially excited about the EPA’s involvement, but she noted its findings regarding the severity of the contamination have been highly concerning.
“I was extraordinarily optimistic, to be honest, because I thought that the EPA had the authority and the resources to finally help us,” Loch-Caruso said. “In the case of the Gelman contamination, they right away focused on the groundwater contamination as the most significant pathway for human exposure, and they gave it the maximum score possible, 100.”
In 1984, Rackham student Daniel Bicknell was the first person to identify 1,4-dioxane in Ann Arbor’s Third Sister Lake, creating a report detailing the contamination. Following a 1992 circuit court order requiring Gelman Sciences to contain the plume and prevent water use in contaminated areas, Gelman Sciences, bought by Pall Corporation in 1997 and now under the Danaher Corporation, remains responsible today for the clean-up process with EGLE as the enforcement lead for the site.
Chris Svoboda, senior environmental quality analyst for EGLE, wrote in an email to The Daily that the primary mitigation efforts to clean the Gelman plume are a pump-and-treat remediation, overseen by EGLE.
“Contaminated groundwater is pumped from extraction wells located both on and around the former Gelman property, collected at the Gelman property, and treated with a chemical oxidation system that uses hydrogen peroxide (H2O2) to destroy the 1,4-dioxane molecules,” Svoboda wrote. “Since treatment began in 1987, over 100,000 pounds of 1,4-dioxane have been removed from the groundwater.”
Svoboda described the risk of 1,4-dioxane contamination in groundwater to people who lived in the Groundwater Prohibition Zone and said that risk management, in this case, entails EGLE and Gelman Sciences working together to prevent the consumption of the contaminated water.
“In this zone, private wells for drinking or irrigation are not allowed,” Svoboda wrote. “This ensures that people are not exposed to dioxane through their drinking water source. EGLE also monitors private drinking water wells outside of the prohibition zone to ensure that residents are not exposed to dioxane above levels allowed by Michigan law (7.2 parts per billion).”
Despite containment efforts by Gelman Sciences, the plume continues to grow. As it grows, there are concerns the plume could reach Ann Arbor’s main water source, Barton Pond. Svoboda wrote that although the city of Ann Arbor and EGLE have beendedicated to monitoring the city’s water sources and setting up warning systems, EGLE believes more monitoring is necessary.
“There are currently more than 150 monitoring well clusters used to manage the Gelman Plume,” Svoboda wrote. “At this time, EGLE’s position is that more monitoring is needed to ensure the groundwater does not vent to the Huron River above allowable levels as the plume migrates through the Prohibition Zone.”
In the EPA’s proposition to include the Gelman plume in the NPL, the EPA emphasized the need for federal government involvement, due to Michigan’s lack of authority over Gelman Sciences and the contamination clean-up process. The report underscored the state of Michigan’s inability to effectively control the contamination that has continued spreading since the 1960s.
Although Kaufman and Svoboda both wrote that the EPA and EGLE did not know of any research on the Gelman plume at the University, undergraduates, graduates and faculty members have been invested in the plume since the 1980s, including a group of master’s students in 1988 who wrote a document about the contamination in “A Case Study of Environmental Contamination: Gelman Sciences, Inc.”
Loch-Caruso said Charles Gelman’s 30-year financial involvement with the University complicates the process of researching the contamination. The Gelmans, long-time donors to the University, donated a now-defunct professorship and $5 million to found the also now-defunct Center for Risk Science. Loch-Caruso said she co-authored two papers as an unaffiliated citizen activist with her colleagues in Washtenaw County’s Coalition for Action on Remediation of Dioxane.
“I did not do research on the 1,4-dioxane while I had an active faculty appointment at the University of Michigan,” Loch-Caruso said. “It was a little bit politically unacceptable for me to do that.”
U-M alum Yifan Luo researched the Gelman plume as a master’s student and released her practicum on the contamination in 2022. In an interview with The Daily, Luo said lack of funding possibly contributed to the minimal U-M research on the Gelman Plume.
“When I did my research back two years ago, there was no funding for this project,” Luo said. “So basically, there is no way to encourage students to dive into this research project, to learn more, or (use) some better equipment, better modeling strategies for them. I would say that’s one of my biggest concerns for this issue.”
Loch-Caruso co-authored a 2022 study on the dangers of exposure to 1,4-dioxane vapor and the possibility of vaporization within damp basements. Not only is contaminated water dangerous to drink, she said, but it is also dangerous to inhale.
“If you have a damp basement in the line of the plume, and if that contamination is not stopped or mitigated and comes into contact with your basement at 115 parts per billion, our calculations suggest that you are at increased risk for cancer,” Loch-Caruso said.
As of March 2025, the Michigan PFAS Action Response Team has identified another contamination within Washtenaw County associated with a subsidiary of Gelman Sciences. Samples of water collected at 253 Dino Drive, the location of the former subsidiary until 1993, have identified PFOA and PFNA at the site. Although the samples revealed PFAS levels above the lab reporting levels, the samples have not yet shown any instances of drinking water exceedances. PFOA and PFNA belong to another genre of forever chemicals known as per- and polyfluoroalkyl substances, several of which are considered carcinogenic. The next step for the team is to conduct a liability determination to assess who is responsible.
Concerned with the state of the contamination clean-up, the Michigan Synthetic Biology Team, a student-run research and engineering design team, spent 2024 creating an alternative solution for breaking down 1,4-dioxane pollution in drinking water.
In an interview with The Daily, LSA junior Joel Groves, MSBT co-science director, said the team engineered a bacteria with a gene complex known as tetrahydrofuran monooxygenase in order to modify the bacteria to break down 1,4-dioxane.
“We had two desired traits: one being freshwater viability and the other being the ability to break down 1,4-dioxane,” Groves said. “So we took the gene called THFMO from this industrial sludge bacteria and put it into a plasmid, which is the circular piece of DNA, and then we’re able to get that into Pseudomonas putida, and at a very basic level that was the system that we used to break down 1,4-dioxane.”
Engineering junior Aditi Ganesan, MSBT co-president, told The Daily the team used the engineered bacteria, able to break down 1,4-dioxane, in a bioreactor system, which contains the bacteria in a closed system.
“We don’t want to put this genetically engineered bacteria into the environment,” Ganesan said. “Instead we propose housing it in this self-contained bio-reactor, and it can form a biofilm, which means it can aggregate together on a surface.”
In an interview with The Daily, Roger Rayle, co-founder of Scio Residents for Safe Water and member of the Coalition for Action on Remediation of Dioxane, displayed decades of data in a series of graphs and Google Earth maps. Rayle said the dioxane levels found in water samples across the area were higher than Michigan’s water standard of 7.2 parts per billion.
Rayle called on University President Santa Ono and the University to involve itself in research on the Gelman plume in a permanent and substantial way.
“It’s okay for the University to go all in on this with all their 19 schools and colleges,” Rayle said. “Get everybody to work together, not on haphazard projects, one-off projects that don’t build on anything. I want something that’s an ongoing project with the nation’s largest dioxane contamination so we can learn about how forever chemicals like this move through groundwater, different types, different levels and how to find it, define it, come up with solutions for it and help the tens of thousands of PFAS sites that are similar all over the world.”
Daily Staff Reporter Grace Schuur can be reached atgschuur@umich.edu.
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