ANN ARBOR, MI – New tests have found dioxane, a probable carcinogen, in a residential drinking water well more than a mile north of the estimated limit of the Gelman plume, pollution that spread in local groundwater for decades.
A sample at the Ann Arbor Township home, north of Skyline High School, showed contamination above the state drinking water standard, the township announced Monday, Dec. 5.
The resident was advised to use bottled water as a precaution, county officials said.
While follow-up tests showed lower concentrations of the toxic chemical, the finding underscores growing concerns about inadequate pollution monitoring, described by local leaders as a slow-motion environmental disaster.
“We at Ann Arbor Charter Township have long expressed concern about the consent judgment between Gelman and the State regarding not having enough boundary monitoring wells to detect water contamination. underground by dioxane before it affects our residential water wells north of the dioxane plume,” Township Supervisor Diane O’Connell said in a statement, referring to the court-ordered cleanup plan for Pollution.
“This independent finding from the township reinforces our concerns about the lack of sufficient groundwater monitoring,” she said.
Similar concerns prompted Scio Township officials to test wells north of M-14 with a more sensitive testing method than that used by state officials to monitor the plume. They found low levels of contamination, including some near the Huron River, Ann Arbor’s main source of drinking water.
Read more: Tests find Ann Arbor dioxane plume contamination in wells near Huron River
But the results released by the Township of Scio all fell below Michigan’s drinking water standard of 7.2 parts per billion.
Still, clean water advocates have long argued that residents should be aware of any level of contamination, pointing to stricter standards in other states.
And an initial test at the Ann Arbor Township well this fall came in at 9.1 ppb, above the state standard, local officials said. A second test result showed 1.9 ppb, and state officials, using a less sensitive method, found no contamination.
Further tests are planned in and around the home, according to township officials.
Dan Bicknell, an environmental remediation professional credited with discovering the spread of pollution from the now defunct Gelman Sciences filter manufacturing plant off Wagner Road in 1984 advised the township on the trial program.
He said the township analyzed a well sample to make sure the contamination couldn’t have come from a chlorinated solvent spill, determining that its source was the Gelman plume instead.
The varying concentrations detected at home are due to the plume not being homogeneous in groundwater, Bicknell said.
“The resident has been advised to use bottled water as a precaution while additional sampling takes place,” Washtenaw County Environmental Health Director Kristen Schweighoefer said in an email.
The county and the Michigan Department of Environment, Great Lakes and Energy (EGLE) have offered to provide drinking water, she said, and they are working together on next steps.
Township and county officials will be home Tuesday to take a “split sample” of the same water source to be tested at an EGLE lab and by the township’s supplier, to compare results, the gatekeeper said. word of EGLE, Jill Greenberg.
The results, available from the EGLE laboratory within days, will guide future actions, she added.
The well is located less than half a mile from the Huron River and test results show that the Gelman plume appears to be moving toward Barton Pond, a major source of drinking water in the Ann Arbor area, have said township officials.
Read more: New test results show levels of dioxane pollution in Ann Arbor waters
Ann Arbor regularly samples its drinking water intake at the pond and its treated drinking water, and although traces of dioxane have been detected in recent years, city officials maintain that it is safe to drink.
Bicknell says test results from the new township show some of those responsible for the plume didn’t fully catch on, moving to an area filled with residential wells.
The data “confirms the finding that much of the Gelman dioxane plume has not been recognized by the state and Gelman,” he said in an email, adding that existing cleanup actions do not stop this migration.
Bicknell sent the results to the EPA, which is currently evaluating the Gelman plume for designation as a Superfund cleanup site, among the most contaminated locations in the nation.
EPA involvement is the only avenue that will protect residents, he has long argued, and Bicknell hopes federal officials will use the information in their assessment process.
“The Gelman site poses an imminent and substantial danger to public health and the environment,” he wrote to them.
More from Ann Arbor News:
More residential wells have been found to be contaminated with dioxane, stoking fears of the Gelman plume spreading
Michigan Court of Appeals Overturns Cleanup Order in Ann Arbor Pollution Case
Water tower marking the site of a notorious industrial polluter demolished near Ann Arbor
Pedestrian Safety Improvements Planned for Hazardous Areas Along Amtrak’s Michigan Line
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