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DEQ official responds to concerns over Ann Arbor dioxane plume clean-up, standards

Feb 19, 2016

Credit City of Ann Arbor

On Thursday, three Ann Arbor officials joined Stateside to talk about the dioxane plume that is working its way toward the city’s main drinking water supply.

For the last 30 years, the plume of a colorless, odorless toxic chemical created by Gelman Sciences on the city's west side, has contaminated the groundwater. Cleanup has been underway, but has done nothing to slow the spread.

Matthew Naud, the environmental coordinator for the city of Ann Arbor; Sabra Briere, a member of Ann Arbor City Council; and Evan Pratt, the Washtenaw County water resources commissioner, have criticized the state's standards regulating 1,4-dioxane. 

The standard for 1,4-dioxane contamination in many places around the world is three parts per billion. Naud said the state used to hold to that standard, but now it is set at 85 parts per billion.  

U.S. Rep. Debbie Dingell recently wrote an open letter to Michigan Department of Environmental Quality director Keith Creagh, seeking stricter regulations for 1,4-dioxane.

Credit Ewashtenaw.org: http://bit.ly/1XCy6qr / Washtenaw County

Robert Wagner, Michigan Department of Environmental Quality's Remediation and Redevelopment Division chief joined Stateside to give the department's side of the story today.

When asked why it's taking so long for the DEQ to put greater restrictions on 1,4-dioxane, Wagner said there's not an immediate threat.

“With respect to the city of Ann Arbor, no one is exposed or drinking 1,4-dioxane, nor has that happened,” said Wagner. “So while we clearly understand that people are concerned about it and they want to know what’s going on and they want to make sure they’re water is safe, as do we … no one at the moment or in the near term, is threatened with drinking water that would contain 1,4-dioxane.”

Councilwoman Briere told Stateside on Thursday that private water wells have already been contaminated by the dioxane plume. Wagner says those wells are located in Scio Township, which is located on the west side of the city.

“Specifically, we are aware of those and we are prepared to take care of those locations in the event that the concentrations of 1,4-dioxane exceed either our current clean-up criteria or our new proposed clean-up criteria."

But the main question Ann Arbor residents have is: How likely is it that the plume will reach the Huron River? Wagner says it won’t.

“As part of the clean-up, they are currently running groundwater purge and treat systems to reduce those high concentrations,” said Wagner. “It involves large diameter groundwater wells that are placed into these core areas where there are high concentrations and then groundwater is extracted containing the high concentrations to the surface, the contaminant is removed and then the cleaned up water is discharged.”

Listen to the full interview below to hear more details about how the regulations for 1,4-dioxane are created, what the DEQ’s contingency plan is if the plume reaches the drinking water supply and more. 

Listen to the full interview below. 

*This post has been updated