4-mile contamination plume continues to move toward Ann Arbor's primary water source

Posted at 4:54 PM, Aug 10, 2022
and last updated 2022-08-10 18:22:55-04

ANN ARBOR, Mich. (WXYZ) — A massive contamination plume in groundwater in the Ann Arbor area is continuing to spread and no one knows where or if it will stop.

"This is probably the nation's largest, if not the world's largest dioxane contamination of its type because they used it pure," said Roger Rayle, who has been collecting data on the contamination plume and its source for years.

The groundwater is contaminated with 1, 4 dixoane, a likely human carcinogen, which was released in the 1980s by Gelman Sciences on Wagner Road in Scio Township.

An unmarked building belonging to Gelman Sciences, a former manufacturer of medical filters, still exists on the same site, but it only serves as a location for the company and some workers to treat contaminated water, per a court order.

The toxic chemicals were found in surface waters and groundwater and, ultimately, residential wells.

"We were told don't drink the water. Don't bathe in the water. Don't use the water for anything," said Marianne Martin, who was among some of the first residents living in the affected area of Scio Township to be switched to water from the City of Ann Arbor.

Martin said, over the years, there has been suspicion that some cancer cases were tied to the contaminated water.

What's now referred to as the "Gelman plume" is estimated to be about four miles long and about a mile wide. It's now in areas of Scio Township and the west side of Ann Arbor. The plume is moving at a rate of about a foot a day, according to Dan Hamel of the Michigan Department of Environment, Great Lakes, and Energy (EGLE).

"We are monitoring and continue to monitor to make sure that levels don't increase to harmful concentrations," Hamel told 7 Action News.

But that the plume appears to be headed north to Barton Pond and east to the Huron River. Barton Pond and Huron River are of great concern because they are Ann Arbor's largest sources of drinking water.

"Our water is safe, but that's only through constant vigilance and the good work of the people that are at the water treatment plant," said Ann Arbor City Councilman Jeff Hayner, who supports the EPA taking the lead in the cleanup by making it a Superfund site.

Roger Rayle speaks on Gelman Sciences contamination plume

A "Superfund site" designation gives the EPA more control and power to force a company to clean up its pollution or reimburse the government for having the work done.

In 2021, EGLE requested that EPA restart their assessment of the Gelman site on the federal National Priorities List associated with Superfund sites.

The cleanup work Gelman has been doing is through a court order after the State of Michigan took the company to court years ago.

But some say Gelman is only doing the minimum and more needs to be done.

"EGLE doesn't have the wherewithal to fight a multibillion-dollar company in state court," said Rayle, who is chair of the Coalition for Action on Remediation of Dioxane (CARD).

Rayle is also part of the non-profit group Scio Residents for Safe Water, which collects and shares the latest information on the Gelman plumes on their website

Rayle believes there are some local Ann Arbor city officials who don't want the stigma of being a Superfund site.

"But instead we have the stigma of not knowing even what the problem is," said Rayle, adding that he believes Gelman, now owned by the Danaher Corporation, uses a confidentiality agreement to shield them from having to disclose all that is known about the plume and its effects,

No one from the Gelman site on Wagner Road would not allow 7 Action News to videotape areas where the company is reportedly treating any contaminated water. The site manager referred us to Michael Caldwell, the company's attorney.

"Gelman is in compliance with all obligations under the applicable Consent Judgement and amendments," Caldwell wrote in a statement. "Gelman continues to work closely with EGLE to implement a remedy that is protective of human health and the environment."

"We're still finding 4,000 parts per billion of dioxane in new layers that, maybe the company knew about four years ago, but if they did, they didn't share it. So, that's a problem," Rayle said.

Because of the toxic plume, any homes and businesses inside what's called a "Prohibition Zone" (see map of red bordered area below or here) that were on well water have had to switch to city water.

The prohibition is "against installing or maintaining wells for drinking water or irrigation purposes," according to the Washtenaw County Health Department.

Jennifer Conn, the health department's public health engineer, said no one in the Prohibition Zone can water their grass with well water because of the possible risks.

"So. theoretically, if you were extracting that contaminated water and spraying it over your lawn, it could become aerosolized into the air and somebody's walking by could be covered in it. So they just want to prevent all possible exposures," said Conn.

Conn said she welcomes anyone with questions about the Gelman plume to contact her by phone at (734) 222-3855 or emailing

EGLE and the Washtenaw County Health Department sampled over 200 drinking water wells for dioxane.

The following is according to the Washtenaw County Health Department:

"If your well water has been tested and is at or below the EGLE drinking water criterion of 7.2 ppb, it is considered okay to use the water for drinking (including making things like tea and coffee). Limited information is available on potential risks to infants from 1,4-dioxane exposure. If 1,4-dioxane is detected in your well water, but is at or below the EGLE drinking water criterion of 7.2 ppb, it is recommended you talk with your pediatrician and use bottled water for preparation of infant formula.

If your well water tests above the EGLE drinking water criterion of 7.2 ppb, you will be provided with bottled water by EGLE until you can be connected to city water."

Councilman Hayner believes it's just a matter of time before the city is going to have to deal with the Gelman plume at the city's water treatment plant.

"When we're redesigning our plant, we're leaving space in that treatment train to deal with dioxane in the future," Hayner said.

Hayner is not alone in thinking there needs to be more aggressive remediation at the Gelman site.

"I don't think they've removed enough material from the source. I think they should be getting on site and digging away at that source material. I think they should be pumping and hauling away. And I think they should also improve their pumping and treating."

Hayner said more Gelman should also have to set aside funding to address the city's increased cost of expanding their water treatment facility.

Gelman and its contaminated water have already cost Marianne Martin. She said the money she spent improving her well was wasted when they could no longer use it.

Gelman is responsible for paying for homes to make the switch to city water.

Martin said she and her neighbors had to be annexed to Ann Arbor when they had to switch to city water and that meant her property taxes increased.

And as the plume continues to move, Martin knows it's just a matter of time before other households may have to take on the additional costs they, too, may not have anticipated.

Martin also believes Gelman should have been forced into more aggressive remediation early on.

She said, "The mistake, of course, was letting it go so long because now I don't know how they're going to control it."