ANN ARBOR, MI - The Gelman dioxane plume in Ann Arbor is eligible for further consideration of a federal Superfund cleanup, the U.S. Environmental Protection Agency has determined.
But at least for now, the EPA is suspending the process to designate the plume as a Superfund site.
The EPA instead will let the Michigan Department of Environmental Quality continue to oversee state regulatory efforts to manage the risks posed by the toxic chemical pollution that's been spreading through the area's groundwater for decades. The current plan is to let it spread and eventually reach the Huron River.
The EPA announced its long-awaited decision in a set of letters dated Nov. 7 and sent to local and state officials.
The decision is being welcomed by the DEQ, while it's seen as concerning to some local officials and residents who have hoped for a Superfund cleanup.
The DEQ has been overseeing pump-and-treat remediation and monitoring activities with regard to the Gelman plume for years, and the EPA intends to watch over those activities for the next year, reserving its option to pursue enforcement action in the future.
Scio and Ann Arbor townships, along with the Sierra Club's Huron Valley Group, submitted a Superfund petition to the EPA in November 2016, hoping to get the plume on the National Priorities List.
Their hope has been that the EPA, working with the U.S. Department of Justice, would force the polluter to pay for restoration of the polluted groundwater aquifer and halt the plume's further migration.
They argue the dioxane pollution, first discovered in the 1980s and found to be coming from the Gelman Sciences manufacturing complex on Wagner Road, hasn't been properly managed under DEQ oversight and court orders dating back to the 1990s.
Dioxane in Ann Arbor's groundwater: a slow-motion environmental disaster
The EPA announced in February it would take a fresh look at the matter and conduct a preliminary assessment to determine whether the plume qualifies for a federal Superfund cleanup.
The EPA previously conducted an assessment in 1985, concluding the plume was potentially eligible for placement on the National Priorities List under the Comprehensive Environmental Response, Compensation and Liability Act, or CERCLA.
The plume has continued to spread since then, now covering an area more than three miles long and a mile wide.
The EPA stated in a Nov. 7 letter to Ann Arbor Township Supervisor Michael Moran that the Gelman plume scores above 28.5 on the EPA's Hazard Ranking System, which assesses the relative potential threat to human health or the environment.
A score below 28.5 would disqualify the plume from placement on the NPL. A score above 28.5 means it qualifies for further investigation and evaluation in the NPL listing process.
The EPA assigned Michael Berkoff, an environmental scientist, to evaluate information and current/future risks to human health, using information provided by the DEQ and Washtenaw County.
"Information reviewed indicates that actions have been taken to prevent current exposures to people via drinking water contaminated from the Gelman 1,4-dioxane release," states the Nov. 7 response letter to Moran from Margaret Guerriero, acting director of the EPA's Superfund division.
"We have heard from community stakeholders that the Gelman release may be posing an ecological risk; however, EPA has been unable to obtain data relating to potential ecological risk."
Family with 3 children living in home with dioxane-poisoned water
The EPA received a Sept. 29 letter from the Michigan DEQ recommending referral of the matter to the DEQ for further investigation and response actions. The DEQ stated in its letter that the Gelman plume is being addressed through state actions in keeping with a Washtenaw County Circuit Court consent judgment that dates back to 1992 and has been modified multiple times.
"Gelman continues to pump and treat contaminated groundwater at the rate of approximately 500 gallons per minute, and to monitor the plume pursuant to an MDEQ-approved monitoring plan," the DEQ wrote to the EPA. "In addition, the MDEQ monitors residential wells in collaboration with Washtenaw County Environmental Health in areas proximate to the groundwater contamination to (ensure) nobody is drinking contaminated groundwater."
The DEQ noted it is negotiating with Gelman and local parties in an ongoing court case to modify the consent judgment once again and require compliance with Michigan's recently revised exposure criteria for dioxane, lowering the allowable level of dioxane in residential drinking water from 85 parts per billion to 7.2 ppb.
Based on the EPA's assessment of current response actions, and the status of legal negotiations between the state, polluter and local parties trying to renegotiate the consent judgment governing how the plume is to be managed, the EPA decided referral to the DEQ is appropriate at this time. The EPA indicates it will designate the plume as "Other Cleanup Authority - State Lead" in the EPA's Superfund Enterprise Management System database.
"The Gelman release will remain on EPA's active Superfund program site inventory," the EPA's letter to Moran states. "EPA reserves the option to pursue enforcement action at the Gelman facility in the future and does not waive CERCLA authority."
The letter further indicates the EPA's technical staff will continue to review data about the plume and response actions, and the DEQ will submit quarterly reports to the EPA for at least one year.
The DEQ's quarterly reports, beginning in January 2018, are expected to include a summary of activities during the past quarter, including data collected from testing residential wells, monitoring wells and other water sources, as well as information on remediation activities and updates on tracked issues and concerns.
The DEQ also has been receptive to the EPA's suggestions for how to improve communications with stakeholders, the EPA indicates.
Dan Bicknell, a former EPA Superfund enforcement officer who is credited with discovering the Gelman plume in the 1980s, helped submit the Superfund petition last year, working with the two townships and the local chapter of the Sierra Club.
Bicknell argues the EPA should continue with the normal Superfund designation process by performing a site inspection and investigation and not let special interests get in the way.
"The DEQ remedy is not protective of public health, as it allows for the continued spreading of the Gelman dioxane plume to township residential wells and through the Old West Side of the city," he said in an email. "For over 30 years, the DEQ has demonstrated that it is not capable of obtaining a cleanup that protects our homes."
In a press release responding to the EPA's decision, the township supervisors in Ann Arbor and Scio, as well as the Sierra Club's local chapter, expressed concern.
Moran, Ann Arbor Township's supervisor, called the EPA's decision "a very negative development for our community."
He said local governments and community groups have worked for many years with the DEQ on remediation options and unfortunately the DEQ has been unwilling or unable to obtain a protective cleanup that safeguards Ann Arbor Township's drinking water supply.
"Many Scio Township drinking water wells have been contaminated with dioxane, yet the DEQ remedy has not prevented the dioxane plume from expanding towards other residential wells in the township," said Jack Knowles, Scio Township's supervisor.
Knowles said the lack of federal action to move the Superfund designation process forward will not help protect residents and their properties from further dioxane contamination.
Dioxane is classified by the EPA as likely to be carcinogenic to humans by all routes of exposure. It also can cause kidney and liver damage, and respiratory problems. Short-term exposure to high levels of dioxane in the air can cause eye, nose and throat irritation.
Just a few parts per billion in drinking water, with long-term exposure, poses a 1 in 100,000 cancer risk, according to the EPA. The expanding Gelman plume already has poisoned many area wells and trace amounts of dioxane were detected in shallow groundwater on Ann Arbor's west side last year.
There still are homes on well water in Scio Township on the edge of the plume where low levels of dioxane have been detected in the water. A family with young children was living in a house on Jackson Road last year where the water had dioxane levels that ranged anywhere from 13 to 54 ppb. Because that was below the state's outdated 85-ppb standard, the polluter -- under the DEQ's oversight -- sent the family reports saying the water was safe.
The Superfund petitioners argue an EPA Superfund cleanup would provide better protection than the DEQ approach, restoring the polluted aquifer so that the water is safe to drink while providing a contingency plan for Barton Pond, Ann Arbor's main water source.
Nancy Shiffler, chairwoman of the Sierra Club's Huron Valley Group, said the club is disappointed with the EPA's decision to keep the Gelman plume under the state's cleanup program for now.
"We have been concerned about a lack of follow-through in the DEQ's monitoring and data collection," she said. "As in Flint, we need the federal government to assist the local community with this large groundwater contamination problem which presents an imminent and substantial endangerment to public health and the environment."
The petitioners argue more private residential drinking water wells are in the potential path of the plume and they're worried about Barton Pond being impacted as the plume expands. They're also worried about the risk of dioxane in shallow groundwater intruding into homes in Ann Arbor in the form of toxic vapor.
Gelman Sciences was acquired in 1997 by Pall Corp., which was acquired in 2015 by Danaher Corp., a multibillion-dollar corporation that some local officials and residents argue has the financial resources to do a better cleanup.
The polluter has spent millions doing pump-and-treat remediation over the years to remove dioxane from the groundwater. However, the rate of pumping and treating has slowed in recent years and some want to see it increased to better contain the pollution and minimize threats to public health and the environment.