LANSING (AP) — State officials are proposing a tougher cleanup standard for a toxic chemical that has contaminated groundwater beneath the city of Ann Arbor.

The chemical is known as 1,4-dioxane, an industrial solvent. Federal agencies say long-term exposure could cause health problems, including cancer.

READ MORE: Michigan Matters: The Political Road Ahead

The Michigan Department of Environmental Quality says its new standard would significantly lower the threshold for requiring cleanups of sites polluted with dioxane.

A plume of the chemical from a former Ann Arbor manufacturing plant has tainted three square miles of groundwater, although the DEQ says the city’s drinking water supply has not been affected.

READ MORE: 'My Name Is Sara' Film On Holocaust Survivor Premieres In Metro Detroit

DEQ remediation chief Bob Wagner says the action on dioxane is part of an update of cleanup standards for 308 hazardous substances in Michigan, based on scientific information about toxicity and exposure risks.


MORE NEWS: Dearborn Homecoming Festival Kicks Off This Weekend

Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.