State officials have a new water contamination investigation on their hands: what is the source of newly-discovered contaminants found in the groundwater near Slauson Middle School in Ann Arbor?
The Michigan Department of Environmental Quality discovered the chemicals trichloroethane and chloroform there after conducting tests for a different chemical - 1,4 dioxane.
The 1,4 dioxane is a known contaminant from the chemical company Pall-Gelman. The plume of 1,4 dioxane is slowly moving underneath Ann Arbor towards the Huron River.
People became concerned there might be high levels of 1,4 dioxane in water very close to the surface in Waterworks Park near Slauson.
Tests showed there was some - but at very low levels, not enough, according to state officials, to be concerned that the chemical could get into the air in buildings through contact with their foundations.
But chloroform was detected in the water at about 5 parts per billion in some of the tests. That level is above the state's proposed residential vapor-intrusion screen level of 1 ppb.
Mitch Adelman of the DEQ says the state will have to investigate, but he says there's no threat to people's health.
"Even though the level exceeds it (the proposed screen level), the groundwater is at least 4 feet below the nearest foundation where it was discovered," he says.
Adelman says the Department will do what it can with the resources it has. But if the investigation requires the installation of testing wells to track the contamination to its source, he doesn't know where the money will come from.
He declined to speculate what kind of industry might be responsible for the new contaminants.
State taxpayers last approved an environmental cleanup bond in 1988, and that money has long since run out.