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Last week, three wells north of M-14 Ann Arbor were discovered to contain dioxane, a suspected human carcinogen found in groundwater that is not easily biodegradable. 

The new wells are just under a mile north of the previously known Gelman dioxane plume boundaries and were discovered by Scio Township’s independent testing of wells that began in July and September of this year. 

For decades, the Ann Arbor community has expressed concern over the increasing levels of dioxane in its wells as a result of the Gelman plume. The Gelman plume refers to the spread of the 1-4 dioxane chemical in soil and groundwater in northwest Ann Arbor. 

The spread began after manufacturing company Gelman Sciences used 1-4 dioxane to manufacture microporous filters from 1966 to 1986. Gelman did not properly dispose of the chemical waste and the dioxane plume spread underground to lakes, rivers and drinking water.

On Nov. 12, U.S. Rep. Debbie Dingell, D-MI, wrote a letter to the Environmental Protection Agency urging them to pay attention to Gelman plume and evaluate the toxicity of the wells. 

​​”It is our joint responsibility to swiftly protect the public health and environment from these toxic carcinogens that now appear to be spreading further northward through the groundwater,” Dingell wrote. 

After much debate, Gov. Gretchen Whitmer sent the EPA a letter in April requesting to be considered for the EPA Superfund Cleanup initiative and to be put on the National Priorities List. In addition to pursuing federal aid, the city of Ann Arbor has been engaged in a lawsuit with Gelman Sciences since 2016. 

In May, the Washtenaw County trial court ruled to implement the fourth iteration of a consent judgment, or a document requiring Gelman Sciences to clean up and monitor the dioxane plume.

Daily Staff Reporter Nirali Patel can be reached at