Q. What will the City of Ann Arbor do if the “Gelman Plume” contaminates Barton Pond? Is there an alternative source of water? 

A.  This fiscal year the city will install two “sentinel wells” to watch for the plume approaching Barton Pond, which provides most of the city’s drinking water. Water Treatment Plant unit manager Brian Steglitz emails that, “the court-ordered containment of the plume requires the polluter to ensure that 1,4-dioxane does not migrate toward the city’s water supply. If 1,4 dioxane is detected above the court-identified action level outside of the existing prohibition zone, the polluter is required to modify their containment system to capture it.”

If needed, the city has identified potential alternative water sources. These include new groundwater sources and water purchased from the Great Lakes Water Authority (which draws water from Lake Huron and the Detroit River).

Alternatively, the water treatment plant could be enhanced to remove 1,4 dioxane, just as improvements have been made in recent years to treat cryptosporidium and to remove PFAS. This approach appears to be the least costly, and it retains local control. 

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