The public might not get to see a new plan to test and track a toxic groundwater plume that's been spreading for years in the Ann Arbor area.
Pall Corporation is responsible for the dioxane plume. It developed and submitted the monitoring plan to the Michigan Department of Environmental Quality – and marked it "confidential."
Bob Wagner, chief of the MDEQ's Remediation and Redevelopment Division, said department officials are asking Pall to explain why the company thinks the plan should be treated confidentially.
Wagner said the Attorney General's office will review whether a court consent decree allows the state to let the public – and Ann Arbor – see the whole plan or parts of it.
Ann Arbor Mayor Christopher Taylor, says transparency is key.
"It is very important that we in Ann Arbor and throughout the area understand what the polluter will be doing in order to clean up the problem that they have caused," Taylor said.
Pall Corporation did not reply to requests for comment.
Earlier this week, Ann Arbor City Council passed a resolution calling upon the MDEQ to enact new standards that would reduce the permissible levels of 1,4 dioxane, a probable carcinogen, from the current state standard of 85 parts per billion (ppb) to 3.5 ppb which is the standard adopted by the federal Environmental Protection Agency.
According to the resolution, the dioxane plume, which originated at the Pall-Gelman site, is traveling toward the Huron River and raises concerns that it could eventually contaminate a primary source of drinking water for Ann Arbor and surrounding communities.
"If there is a new standard imposed, then we are able to reopen the legal proceedings in order to make the polluter clean up to the new standards," Taylor said.