Official says company will advocate 'in situ' treatment

Sunday, November 30, 2003

As high concentrations of a carcinogenic solvent continue to seep through a low-lying aquifer beneath the city of Ann Arbor, officials are preparing to submit a plan on how to clean it up.

Pall Life Sciences engineers will submit their feasibility study exploring several options to state officials Dec. 15, with the hopes of meeting a 2005 deadline for cleanup.

Pall's Vice President for Corporate Environmental Engineering Farsad Fotouhi said the company will advocate for "in situ" treatment.

That involves injecting ozone into groundwater, which zaps the dioxane. It avoids problems associated with options such as pump-and-treat, which would involve drilling rigs, noisy pumps and water disposal problems.

It also avoids the time delays associated with building a pipeline to pump water back to the company's Wagner Road site or to another disposal site.

But the state Department of Environmental Quality must review the feasibility study and permit the new method, and the company must find a location for the treatment facility, which would still require a construction trailer or two for operations.

But not everyone is convinced that's the best way to go.

Washtenaw County Commissioner Vivienne Armentrout, D-Ann Arbor, said she was concerned about the possibility of a byproduct of in-situ treatment, bromates. Bromates are salts that could create their own contaminant problem if too much resulted from the treatment.

Fotouhi said initial studies by the company have shown the procedure will create bromate levels more than what the federal Environmental Protection Agency standard allows, 10 parts per billion.

"The question is, can we do it under the standard?" Fotouhi said. "We have to be sure both 1,4 dioxane and the byproduct of bromate is acceptable." He said the company would keep working on the technology to make sure bromate levels weren't excessive.

But Sybil Kolon, DEQ's project manager on the Pall cleanup, said if the state is satisfied, in-situ treatment might be the best alternative. The company is performing tests on in-situ at its Wagner Road location.

"We think if it can be shown to be a viable alternative, it might be a good opportunity to address contamination without as much disruption to area neighborhoods," she said, adding that DEQ would not know until Pall turns in its feasibility study on various options by Dec. 15.

Meanwhile, some monitoring wells, drilled to sample the groundwater on the city's west side, have shown an upward trend in dioxane levels. Some wells are now showing contamination levels more than 20 times the state's standards.

Pall has been cleaning up the groundwater contamination since it purchased medical filter maker Gelman Sciences Inc. in February 1997. The water must be cleaned to meet state environmental and health standards of 85 parts per billion or less to protect potential drinking water resources. No one is known to have been made ill from the dioxane contamination.

While the cleanup plan has been controversial as city, state and company officials and area residents weighed in on how it should be done, it looks like the company will reach a court-imposed July 2005 deadline for completion. Failure to make the deadline could result in million of dollars in fines for the company.

But in February 2001, low levels of dioxane turned up in the city's west side Montgomery Well, which has been since taken off-line, a discovery that showed dioxane had reached the lowest aquifer above bedrock. That aquifer was previously thought to be protected from tainted water by thick clay barriers underground.

While other drinking water, from city supplies or residential wells, is not believed to be jeopardized, the state requires groundwater to meet its standards. But performing a cleanup in densely populated part of Ann Arbor would be logistically very difficult, all parties agree.

DEQ and Pall attorneys were ordered earlier this year by District Court Judge Donald Shelton to have a plan and be ready to move with it in February. After a public comment period, cleanup of the last aquifer would begin.

Fotouhi said it is unlikely the company could deal with all of the recently discovered contamination by the deadline. However, he said he is confident contamination in upper aquifers can meet standards by then.

"We have implemented anything humanly possible to meet the court deadline," he said. "If it's possible from an engineering point of view, we will accomplish it."

Gelman Sciences used dioxane as solvent for years in its medical filter manufacturing process, ending in 1985. Dioxane-containing wastewater was disposed of by storage in unlined lagoons and by spraying over lawns on site. The dioxane eventually made its way to groundwater supplies.

Since the cleanup began, Pall has pumped and treated more than 2 billion gallons of groundwater.

Tracy Davis can be reached at tdavis@annarbornews.com or (734) 994-6856.