Dayton has shuttered two Mad River well field drinking water production sites over fears of the potential for contamination from a firefighting foam contaminant that could eventually threaten dozens of additional groundwater wells, a city leader said.
Dayton stopped pumping drinking water at seven groundwater wells at the Huffman Dam well field last April where an early warning groundwater monitoring network showed per- and polyfluoroalkyl (PFAS) substances city officials believe were part of a contamination plume migrating from Wright-Patterson Air Force Base.
The two sources of separate contamination could eventually poise a threat to dozens of city groundwater wells in the Mad River well field, Dayton authorities said.
The Huffman Dam and Taits Hill well fields — more than three miles apart — are the “bookends” of the city’s Mad River well field system that counts more than 60 groundwater drinking wells, officials said.
Wright-Patterson, which has worked with city and Ohio EPA authorities over two years on the issue, has said it’s preparing a response.
Dayton reported it discovered polyfluroalkyl substances at less than 10 parts per trillion for the first time in the raw water intake of its Ottawa water treatment facility near the Mad River last November.
A city-owned early warning system of monitoring wells at Huffman detected at least one sample with 35 parts per trillion of the contaminant, according to the city.
“It warns us in enough time that we can mitigate a problem before it actually reaches the (drinking) production wells.” Dickstein outlined the two sources of contamination in a Feb. 21 letter sent to city managers.
Along with the Mad River well field, the others include Miami and Rip Rap Road well fields near the Great Miami River.
The U.S. EPA reported human epidemiology and animal testing studies indicate exposure to the contaminant suggest it may be responsible at certain levels for testicular and liver cancer; changes in cholesterol; low birth weight in newborns; liver tissue damage; and effects on the immune system and thyroid.