MDEQ proposes tougher drinking water standards to protect residents from 1,4-Dioxane
WASHINGTON, D.C. – (RealEstateRama) — The Michigan Department of Environmental Quality is proposing to strengthen the drinking water clean-up standard for 1,4-Dioxane by a factor of 10 in a new rules package under consideration by the agency. The more protective standard is based on new calculations completed by the DEQ using a science-based process, including current EPA toxicity data and Michigan-specific exposure factors. The new rule would change the 1,4-Dioxane drinking water standard in Michigan from 85 parts per billion (ppb) to 7.2 ppb.
The chemical 1,4-Dioxane is an industrial solvent that has been linked to human health concerns at certain concentrations given long-term exposure. The proposed change would affect contaminated sites across the state where 1,4-Dioxane has been shown to be present. The DEQ and the citizens of the City of Ann Arbor have been focused on the standard as it pertains to the Pall-Gelman contaminant plume. The Pall-Gelman 1,4-Dioxane plume has contaminated three square miles of groundwater below the City of Ann Arbor.
The plume has not affected the City of Ann Arbor’s drinking water supply. One Scio Township resident’s well water had 1,4-Dioxane levels greater than Michigan’s new proposed standard. That home has been connected to the city’s water supply. Gov. Rick Snyder’s proposed Fiscal Year 2017 budget includes an additional $700,000 for addressing the Pall-Gelman1,4-Dioxane plume.
“The DEQ’s first priority is to protect public health,” said DEQ Director Keith Creagh. “This revised standard strengthens those protections for all Michiganders. The DEQ is committed to open communications and transparency of our actions in affected communities. We will work with local stakeholders to ensure residents are informed and supported.”
Creagh will take part in a town hall meeting hosted by Rep. Jeff Irwin of Ann Arbor. The event will take place 6 p.m. Monday, April 18, in the auditorium of the Eberwhite Elementary School, 800 Soule Boulevard, Ann Arbor.
“The Ann Arbor community and its leaders have been great partners in addressing this issue, and we look forward to continuing to work with them on addressing the Pall-Gelman plume,” Creagh said.
The calculation of the 1,4-Dioxane criteria is part of a major effort by the DEQ to update the criteria for 308 hazardous substances used to determine cleanup standards across the state. The new state standard assumes an exposure period of 32 years at the level of 7.2 ppb to protect public health.
The Michigan standard will be an enforceable standard. It is based upon the same toxicity level as the U.S. Environmental Protection Agency screening level. However, the federal screening level of 3.5 ppb – which is not enforceable — assumes an exposure period of 70 years. The state standard assumes an exposure period of 32 years to provide a more realistic assumption of risk and greater protections for the public. The Michigan standard will be among the most protective state standards in the country.
The DEQ’s process for updating these standards uses the latest, scientific information from reliable sources as well as Michigan-specific exposure scenarios to ensure the protection of public health, safety and welfare for all Michigan citizens.
“We are in the process of finalizing the update for the cleanup standards for all hazardous substances and their exposure routes and will be releasing all of the proposed standards in April,” said DEQ Remediation and Redevelopment Chief Bob Wagner. “Review of the proposed rules will involve the Legislature as well as provide opportunity for public comment. We plan to finalize the rules as soon as possible with appropriate reviews.”
Contact
Bob Wagner, 517-284-6715
