Madison Water Utility plans to drill a “sentinel” well that would provide an early warning in case a toxic underground plume from Madison-Kipp Corp. moves any closer to an East Side drinking water well.
There are some indications that the toxins may no longer be spreading in that direction, but the water utility doesn’t want to take any chances, said general manager Tom Heikkinen said Friday.
With state Department of Natural Resources oversight, the company has spent millions of dollars removing contaminated soil, monitoring ground water and checking for toxic vapors that can escape from shallow parts of the water table.
But the DNR hasn’t directed Madison-Kipp to pay for about $32,000 in consulting studies commissioned by the water utility or for the expected $100,000 sentinel well. Water utility and DNR officials have discussed whether Madison-Kipp should pay.
A consultant hired by Madison-Kipp said several years ago that the plume seems to have stopped spreading toward Well 8, but an independent expert hired by the water utility to confirm the conclusion reported in 2015 that the company study wasn’t thorough enough.
Preliminary indications are that the plume’s southern edge may have stabilized based on a Madison-Kipp well 600 feet north of the Well 8 that has at times detected very low concentrations of toxins, much lower than monitoring wells closer to the plant, DeMorett said.
The 6-inch hole was drilled as an exploratory well before the 30-inch in diameter production hole was drilled in 1945.
The plume carries another VOC, trichloroethylene, or TCE, a solvent associated with health hazards that include cardiac birth defects in children whose mothers exposed to the compound relatively briefly.