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Dioxane Plume Spreading in Ann Arbor, MI

— March 11, 2019

In Ann Arbor, MI, a dioxane plume from industrial groundwater contamination is flowing relentlessly towards the source of the city’s municipal water supply.

Between 1966 and 1986, Gelman Sciences (now Pall Corp., a division of Danaher Corp.) polluted the groundwater in Washtenaw County, Michigan, with 1,4-dioxane. The dioxane plume has been spreading slowly, steadily, under the city of Ann Arbor, creeping toward the Huron River, the city’s main source of drinking water. And now, the chemical has turned up for the first time in Barton Pond.

In 1958, Charles Gelman, a graduate student at the University of Michigan, worked out a process to manufacture micro-porous filters which, ironically now, could be used to detect air and water pollution. His business, Gelman Sciences, grew from a basement hobby and became an industry leader in the college town of Ann Arbor. Unfortunately, the manufacturing process used 1,4-dioxane, a probable human carcinogen according to the EPA, and instead of finding a responsible way to dispose of their waste, Gelman Sciences simply dumped it on their property, located on Wagner Road. They even used a sprinkler system to more efficiently get rid of the chemical waste.

Ever since, the contamination has been on the move. In 1984, Daniel Bicknell, another grad student from the University, first broke the story after taking water samples at Third Sister Lake, near the Gelman Sciences property. At the time, regulators with the Michigan Department of Natural Resources didn’t believe Bicknell’s findings, but the dioxane plume didn’t care what they thought. It just kept spreading slowly northeastward, contaminating residential wells and forcing people on to the municipal water system. In 2001, the city had to abandon one of the wells that fed that same municipal supply due to dioxane contamination.

The fear has always been that the dioxane plume would eventually reach the nearby Huron River, where the city obtains the bulk of its drinking water supply. Earlier this month, the plume, now 3-4 miles long and a mile wide, did. Recent lab tests found a small amount of 1,4-dioxane in water drawn from a municipal water intake at Barton Pond on the Huron River, and in the city’s treated drinking water supply. Currently, the city claims the water is safe to drink, with dioxane contamination equal to “about one drop of water in an Olympic-sized swimming pool.” However, it won’t always be.

The Huron River flows by, as seen from the bank of the river. It's early spring, with leafless trees and branches and dormant grass around.
A view of the Huron River in Scio Township. Several residents in Scio Township can no longer use their wells due to contamination from the dioxane plume. Photo by the author.

The dioxane plume is relentless, finding its way through drainpipes in another nearby creek which was diverted underground in 1926 but which still reaches the river. Attempts at making Gelman Sciences or its successive owners clean up their mess have been disappointing, despite several lawsuits, including one that was thrown out in 1991, when Judge Conlin decided Gelman had done nothing wrong. The city has been able to mitigate the plume’s spread by pumping groundwater through a purification system and reinjecting it back underground, but that only removes a portion of the poison. Pall (Gelman) is also cleaning up some of the dioxane, dumping treated (but not dioxane-free) groundwater into a tributary of the Huron. Despite the EPA’s criteria for safety being 3.5 parts per billion, Michigan’s DEQ required Pall to clean water to 85 ppb, only recently demanding a level of 7.2 ppb in treated groundwater.

In the long term, Ann Arbor’s municipal water system is doomed. It’s only a question of when the dioxane plume will render city water unusable. According to the EPA, 1,4-dioxane is likely carcinogenic by all routes of exposure, including vapors from contaminated groundwater that could seep into the basements of residents who live on top of the plume. Perhaps one day the EPA will consider the dioxane plume a Superfund site, and taxpayers will pay to clean up yet another corporate mess. In the meantime, in the words of area resident Roger Rayle, we’re simply cutting “job-killing” regulations in favor of “people-killing” regulations.

Related: One Water Problem After Another


Ann Arbor may seek EPA intervention for Gelman plume cleanup
Gelman Dioxane Plume – Ann Arbor, Michigan
Officials investigating spread of 1,4-dioxane in Ann Arbor storm drains
Dioxane detected in Ann Arbor drinking water from Barton Pond for first time
Dioxane Plume Pollution Then and Now
Protecting Safe Drinking Water: Keeping Our Customers Informed (PDF)
History of the Pall-Gelman Dioxane Groundwater Contamination Cleanup
Ann Arbor residents ‘trying to prevent future Flint water crisis’
Pollution Suit Thrown Out; Gelman Wins

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