After four years of negotiations, local officials have come to a proposed agreement on a cleanup plan for the Gelman dioxane plume on Aug. 31. 

The plume’s history goes back to 1958, when the late Charles Gelman began manufacturing micro-porous filters in the local Ann Arbor area. A chemical called 1,4-dioxane was used during the process, and eventually seeped into soil, polluting groundwater at the company’s Scio Township plant.

Over decades, the dioxane spread into a large plume of underground contamination in northwest Ann Arbor. Dioxane was deemed a probable carcinogen and has been found to cause kidney and liver damage as well as respiratory problems.

The newly proposed settlement with polluter Gelman Science Inc. details a thorough plan for a cleanup protocol, which includes expanding prohibition zones and increasing well installments to monitor the plume’s migration through Ann Arbor area’s groundwater systems.

The settlement’s executive summary states there will be “a significant increase in the obligations imposed on Gelman to investigate and remediate 1,4-dioxane contamination at and migrating away from the Gelman site.”

Prohibition zones were also redefined in the proposed settlement. These zones prohibit the use of groundwater in particular areas due to the heightened levels of dioxane. Additionally, the state’s dioxane assessment for drinking water saw a significant decrease from 85 parts per billion to 7.2 parts per billion. Areas within the prohibition zone show levels of dioxane greater than 7.2 parts per billion.

Ann Arbor City Councilmember Ali Ramwali, D-Ward 5, said this agreement is the result of years of negotiations, going back long before he assumed office in 2018. Regardless, Ramwali acknowledged that this proposal is not perfect.

“I think it ultimately is the best agreement the intervenors’ and the polluters’ attorneys can come up to,” Ramwali said. “And ultimately, this agreement is the summation in the totality of improvements that we can make on the current situation. Does it satisfy all our concerns? No, it does not.”

In 2016, the city officially filed a lawsuit against Gelman and has been negotiating since then. The proposed settlement, however, has drawn criticism from local residents who wish to see the federal government intervene.

Dan Bicknell, an environmental remediation professional and former Environmental Protection Agency Superfund enforcement officer, discovered the Gelman plume when he was completing research at the University of Michigan in 1984. He is now the president of Global Environment Alliance LLC and an Ann Arbor resident.

“The state government has failed us for almost 40 years now on this project,” Bicknell said. “And the idea that a local government, who has no expertise whatsoever, can do a better job at compelling this very, again, resistant polluter to do the right thing is not logical.”

Larry Lemke, a hydrogeologist and professor at Central Michigan University, was hired as an expert for the Ann Arbor, Scio Township, Washtenaw County and Huron River Watershed Council’s lawsuit against Gelman. In a series of videos, Lemke gave a thorough rundown of the proposal, saying that the contamination will likely remain in the groundwater system in the future.

“Although concentrations have decreased over time, we can expect dioxane to stay in the groundwater and continue to spread for many years to come,” Lemke said.

Ramwali clarified that cleanup of the plume will never result in completely pristine water levels, regardless of who is in charge of it.

“The way that the dioxane in the natural world, the complexities of our underground aquifer system, the geology and again, the way the dioxane behaves in these conditions, we will never get to pristine levels ever in our lifetime,” Ramlawi said. “It’s just scientifically, technologically impossible at this point in history to get those underground aquifers back to pristine levels.”

Bicknell  said the community is not asking for pristine water levels, but rather reverting the groundwater to drinking water state. He also noted that a Gelman feasibility study found that it was not an impossible feat.

“No one’s asking — and no one ever has ever asked — that it be cleaned up to (perfectly pristine levels),” Bicknell said. “What people have asked in what the U.S. EPA would do in the Superfund program, is that they would restore to drinking water level which is 7.2 microgram per liter.”

As the intervening parties review the proposed settlement these next few weeks, the city will hear public comment on the deal. Ramwali said he is expecting the community to express varied reactions to the proposal.

“I’m sure it’s going to be received with mixed emotions,” Ramwali said. “It’ll be interesting to see what the residents and the community at large have to say but unfortunately this is just a sign of the times of how we’ve destroyed our natural environment. Once you’ve destroyed something as perfect as nature is, there’s no going back.”

Daily Staff Reporter Kristina Zheng can be reached at

Leave a comment

Your email address will not be published. Required fields are marked *