Pollution is close to Lansing drinking water wells. Scientists have a plan to fix it.

LANSING — An underground plume of chemical pollution is creeping toward wells that supply some of the Lansing region's drinking water.

It isn't there yet, and the trust that controls the former General Motors properties, where the pollution started, hope to keep it that way. They proposed removing the pollution by injecting air into the water to encourage bacteria to gobble up the 1,4-dioxane, the pollutant lurking underground.

It's unclear what the project would cost, but it would be among the first and likely the largest use of that remediation method, called "biosparging," on dioxane. It's a high-profile project among pollution remediation experts around the country.

"They’re well known because they're one of the few places that has taken this issue head-on," said David Adamson, Principal Engineer with GSI Environmental in Houston, Texas.

First, the trust needs to present its plans to the community during an upcoming meeting and get approval from the Michigan Department of Environment, Great Lakes, and Energy, the state's newly renamed Department of Environmental Quality.

How dioxane got under the old GM sites

There are few signs left of the GM plants straddling Saginaw Road in Lansing Township. The properties are gated swaths of cracked concrete; scrub trees and brush have grown tall in the years since they shuttered.

The old GM properties are held by the Revitalizing Auto Communities Environmental Response Trust, or RACER Trust, which the federal government established when GM declared bankruptcy in 2011 to clean the sites and get them ready for redevelopment. The trust was funded with federal money and the value of GM assets.

The trust controls four sites in the Lansing area: Plant 5, a 25-acre parcel in Delta Township; Plants 2 and 3 in Lansing Township, which are 72 and 105.25 acres, respectively; and 57-acre Plant 6 in the City of Lansing.

The dioxane plume is underneath Plants 2 and 3 and near Plant 6.

The sites are under a purchase contract with NorthPoint Development, RACER Trust announced in 2016.

Dioxane is an industrial chemical used in laboratories and in adhesives or sealants, according to the EPA.

It's also used to stabilize other chemicals and keep them from breaking down, said Dave Favero, deputy cleanup manager for the Michigan RACER properties. That's why it's usually found with other chemical pollution, not on its own like it is in Lansing Township.

Dioxane was used at the GM Plants as part of a mixture used to clean oil off car parts, but it doesn't like to stay with oil.

"1,4 dioxane is very soluble, so if it's in the oil it would rather be in water," Favero said. "It leaches out and starts to migrate with the groundwater."

More: Cleanup underway at old GM sites

BWL says dioxane levels are safe, but it's moving toward wells

Dioxane in the environment can be dangerous to human health, according to EPA reports. It is likely cancer-causing, and long-term exposure could cause liver, kidney and reproductive problems.

The dioxane plume in Lansing Township is within the Lansing Board of Water and Light's "wellhead protection area" for some of its drinking water wells. Up to 10 of the utility's 125 wells are downstream of the polluted groundwater.

BWL, which provides drinking water to 56,000 customers in Lansing and surrounding townships, started monitoring for dioxane in 2015 when the EPA asked utility companies to test for certain contaminants in their water supplies.

They found a small amount of dioxane — .14 parts dioxane per billion parts water — within the limits of what the EPA considers safe, .35 parts per billion. BWL has monitored for dioxane in the groundwater quarterly since late 2016 and it has never exceeded the EPA's safe limit.

The utility posts monitoring results online at lbwl.com.

"We're supportive of the [RACER] remediation efforts because it's ultimately going to help clean up the site as well as remove any potential contamination to drinking water," said Lori Myott, manager of BWL's environmental services department.

BWL's drinking water wells tap into an aquifer hundreds of feet below the contaminated groundwater, general counsel Mark Matus said. 

The pollution starts on the Plant 3 property and has spread southeast under Saginaw Road to the southerly Plant 2 property. It's now an oblong shape that reaches 80 feet below the surface to the top of the groundwater.

The Lansing-area plume has between 300 and 400 parts dioxane per billion parts water. State regulations say dioxane must be cleaned from the environment if levels reach more than 7.2 parts per billion.

The biggest risk of having dioxane in the environment is its potential to get into drinking water, but most water utility companies rarely monitor for it, Adamson said.

Dioxane was found at 34 sites on the EPA's list of high-priority cleanup sites as of 2016, but agency officials said it may be present "at many other sites."

The RACER sites are not included on that list, but the Adam's Plating Superfund Site — next door to the Lansing Township RACER properties — is.

Another high-profile dioxane site is in Washtenaw County. The plume has contaminated multiple aquifers, according to the City of Ann Arbor, and is moving toward the Huron River. The city has had to shut down one of its wells and some Scio Township residents have had to stop using their well-water systems, Michigan Radio reported in 2017.

More about dioxane

Dioxane isn't a new chemical, but it's not part of most routine environmental testing, Adamson said.

"It’s not a regulated compound in the same way a lot of the chlorinated solvents are," he said. "There’s no federally enforced drinking water standard for 1,4 dioxane, and it’s those drinking water standards that a lot of times drive the cleanup for contaminated sites."

Scientists who specialize in cleaning up pollution are "at our infancy" in understanding how to deal with dioxane, he said.

The chemical was a surprise to the RACER scientists who found it in 2012, Favero said. After detecting it in one well, they continued testing so they could map the pollution plume. 

Scientists and engineers spent years looking for a fix once they realized it was widespread underneath the property.

"It's a very complex situation there," he said. "It hasn't been straightforward to identify an appropriate technology to deal with the 1,4 dioxane plume."

Adamson agreed. A lot of pollution can be cleaned by digging contaminated soil out of the ground, but that won't work with dioxane because it likes to spread through water instead of soil.

Scientists could pump out the groundwater, but it would take astronomical amounts of work, space and money, he said.

"If these sites were easy to clean up we'd put ourselves out of business," he said.

Instead, scientists have to come up with a way to treat the water while leaving it underground.

That's where biosparging comes in.

What is biosparging?

Scientists set up a pilot project to test whether biosparging will work.

The pilot project looks simple — a barbecue-sized propane tank in a fenced storage container, with three narrow pipes extending into the ground. The results are promising, Favero said. Samples taken around the biosparging wells show concentrations of dioxane in the water are dropping.

Here's how it works: The system injects air and a small amount of propane into the contaminated water 80 feet below ground. Bacteria that are naturally present in the environment like to eat the propane, and they turn 1,4 dioxane into carbon dioxide and water while they munch.

"They're going after the propane," Favero said. "The 1,4 dioxane is kind of like salt on the main course."

Biosparging has been done on other dioxane plumes, like one under an Air Force base in California, but it's rare.

If the state approves, RACER scientists and engineers will install biosparging wells starting this year and finish in 2020.

Favero doesn't have an exact cost estimate, but expects the cleanup project will cost more than RACER has set aside for typical expenses at the Lansing Township sites.

"We do expect that we will need money from what was established in the settlement agreement called a 'cushion fund,'" Favero said. "Everyone recognized the cost estimates were put together... pretty quickly to facilitate the bankruptcy, so there was a cushion fund established for certain conditions."

It also won't be a quick clean-up. Engineers plan to build 60 biosparge wells and say it could take 6 to 12 years to fully clean the water. Dioxane-contaminated water would have to run through treatment zones three to four times before it would become safe.

Pollution that has spent decades underground can't be cleaned in a day, Adamson said.

"It's a pretty big challenge, sort of a difficult contaminant to treat," he said. "It's required a lot of work to get to this point, and it's probably going to take a lot of work to get to the point where they feel like they've cleaned the site up and can walk away from their obligation."

Want to learn more? Attend an upcoming meeting:

The Michigan Department of Environment, Great Lakes, and Energy has to approve the biosparging project. 

First, the department is hosting a public informational meeting so the community can learn more about the work and ask questions of the engineers involved.

Here are the details:

• Who: Officials from Michigan Department of Environmental Quality and RACER, plus scientists and engineers contracted to work on the project.
• What: The meeting will start with a 30-minute presentation from engineers about the groundwater remediation project. A question-and-answer session will follow.
• When: 6-8 p.m. April 23
• Where: Lansing Township Board room, 3209 W. Michigan Ave., Lansing

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Contact Carol Thompson at (517) 377-1018 or ckthompson@lsj.com. Follow her on Twitter @thompsoncarolk.