Flint, MI—With a deal on the table for Ashley Capital to purchase the remaining acreage of Buick City, the organization tasked with the former General Motors site’s clean up and sale said they remain concerned with PFAS contamination levels on two areas of the property.
Those areas are a parcel containing a former lagoon and another parcel near the southern end of the property at East Hamilton Avenue—both of which Revitalizing Auto Communities Environmental Response (RACER) Trust discussed in detail during a July 14, 2022 environmental update meeting.
“Those parcels are included in the proposal to sell the property but will not be included in the initial transaction,” said Grant Trigger, RACER Michigan Cleanup Manager.
Trigger said that RACER would retain ownership of those parcels until further clean-up efforts got them to a point where “it would be appropriate to develop” the parcels, at which time Ashley Capital, should it be the final buyer, could take control.
In the meantime, RACER is monitoring and working to mitigate both parcels’ levels of perfluoroalkyl and polyfluoroalkyl substances (PFAS), man-made chemicals which can be found in cleaning products, paint and sealants, and nonstick cookware among many other items.
The Centers for Disease Control (CDC) and Prevention maintains that health effects from exposure to low environmental levels of PFAS are “uncertain,” though peer-reviewed studies have shown increased risk of some cancers, developmental delays in children, and reduced immune response according to the Environmental Protection Agency.
While no groundwater at the Buick City site is used for Flint’s drinking water, the property’s PFAS levels are a concern because such chemicals do not break down naturally in the environment—meaning if the contamination moves through water or soil it could still affect surrounding areas or accumulate in nearby fish and wildlife without remediation efforts.
The Lagoon
During the environmental update meeting, Trigger shared recent groundwater and surface water data that showed many testing sites at Buick City’s former lagoon area have PFOS (a subcategory of PFAS) concentrations at greater than 1,000 nanograms of substance per liter or ng/L.
While this is well above the PFOS surface water standard of 12 ng/L, Trigger said that because the property’s groundwater is not used for drinking water on-site or in the adjacent community, RACER is not required to meet drinking water standards.
However, Trigger added in an email to Flint Beat: “The goal, therefore, is to manage the contamination on-site so it does not migrate off site and exceed surface water standards.”
And when it comes to the lagoon, as far as RACER and its contractor Arcadis can tell thus far, none of that area’s contamination has reached the Flint River, which borders the site on the east side of the property, beyond James P. Cole Boulevard and Interstate 475.
“So what we’re trying to do is address it where it is now and prevent it from getting into the river,” Trigger said.
Addressing the PFOS concentration required pumping all of the water out of the lagoon, treating it in activated carbon tanks—think industrial-strength Brita water filters—and then releasing it into a city of Flint sanitary sewer.
RACER is now spreading activated carbon, in granular and powdered form, over the lagoon area and testing reeds that were previously growing alongside the water for further PFOS contamination.
Trigger said they hope to wrap up remediation work in the lagoon area by the end of next month, though in-filling the lagoon with pre-tested soil from local highway construction projects may push beyond that deadline.
East Hamilton Avenue
The more concerning parcel for RACER, said Trigger, is the area around East Hamilton Avenue at Buick City’s south end.
“There’s significant PFAS contamination here,” Trigger said, pointing out multiple testing locations in the area that showed PFOS groundwater concentrations greater than 100,000 ng/L.
He noted the good news is that across the road PFOS levels are mostly testing near or at the 12 ng/L concentration standard, and soil samples are also in the low to accepted range.
RACER has already installed bulkheads, or barricades, on two storm sewers in the area within the last year. Since then, one of the sewers has shown a significant decrease in PFOS concentration at its outfall, however the other sewer has not shown a difference.
“We should add that these sewers are quite old,” said Chris Peters, vice president of Arcadis. “The groundwater is shallow and groundwater enters and can infiltrate the sewers, so there’s still impacted groundwater entering the sewers.”
Peters said RACER and Arcadis are doing additional work to address the sewer lines and manholes servicing East Hamilton Avenue in an effort to stop any further PFOS contamination from Buick City from entering that sewer’s outfall area.
Additionally, Trigger said RACER hopes to use findings from the lagoon area’s remediation to help strategize a solution for the higher PFOS concentration levels at the East Hamilton Avenue parcel.
“We’re doing field work right now that we’re going to evaluate: could we use it here?” Trigger said. “This is a much bigger problem. And so what we learn at the lagoon, we’re going to try to apply to what we might do next year.”
In the meantime, RACER Trust is completing a study to help them understand the flow of contaminated groundwater from the East Hamilton Avenue parcel.
“We need to know what’s happening with that material, so as we complete the work in terms of plugging storm drains and so forth … we hope to stabilize the conditions and then do the tracer study, as that tracks the direction of movement,” Trigger said. “That helps us evaluate what we do next.”
Both Trigger and Peters noted that PFAS elimination techniques are still in their infancy, and there are many entities working on possible remediation strategies from activated carbon to incorporating specific plants that might pull contaminants from soil.
“We’re going to continue to look at those technologies as we better understand the site,” Trigger said.
In a prior interview on the potential sale of Buick City to Ashley Capital, Susan Harvey, the senior vice president of the investment group, said she had “full faith” that RACER Trust would put the site into “exactly the condition” Ashley Capital needed.
RACER officials said they are prevented from discussing deadlines surrounding the pending deal with Ashley Capital due to a non-disclosure agreement.
A video of RACER Trust’s July 14 environmental update presentation can be found here.