Company will test using peroxide to neutralize pollution

Thursday, March 25, 2004

Some experts added their voices Wednesday night to a chorus questioning the safety and effectiveness of cleaning up groundwater pollution from the Pall Life Sciences by injecting hydrogen peroxide into the underground water supply.

Environmental engineers and university professors told community members at a meeting on the ongoing 1,4 dioxane cleanup in Ann Arbor that a combination of methods might be more effective. That might include pumping water from various sites and treating it.

Pall has been pumping water from upper level aquifers and treating it, but has been searching for a different way to remove dioxane from deeper aquifers. The company will test using peroxide, which reacts with dioxane and changes it to less harmful chemicals.Responding to a question about whether "in-situ" treatment would simply add more bad chemicals to aquifers beneath Ann Arbor, Michigan State University environmental engineering professor Susan Masten said it was possible.

Above ground in a lab, scientists could engineer the chemical treatments, but underground, "we don't even know where (the pollution) is going, much less how to control it," Masten said.

She mentioned a similar cleanup in North Carolina in which heat and escaping gasses from underground chemical reactions exploded at a cleanup site.

"Concentrations as low as 11 percent (hydrogen peroxide) can cause groundwater to boil," she said. "Pall's solution is, 'we won't use solutions greater than 10 percent."'

"There are some real problems with this notion of in-situ chemical oxidation," said Larry Lemke, a senior lecturer at Wayne State University and a hydrogeology expert.

"All of these unanswered questions about explosions and bubbling and what-have-you are extremely disturbing," said west side resident Pat Ryan.

But Farsad Fotouhi, Pall Corp.'s vice president for corporate environmental engineering, said after the meeting that the chance of a reaction-induced explosion is nil.

The company will test the peroxide injections at wells in the parking lot of the Maple Village Shopping Center. Fotouhi said that several wells there would help vent oxygen bubbles released from the reaction, and the low-concentration peroxide solution would be added slowly in small batches with constant monitoring, he said.

Fotouhi also pointed out the test plans, which were ultimately approved by the state Department of Environmental Quality, had been reviewed by a technical committee of scientists from the U.S. Geological Survey, MSU, DEQ and elsewhere. He and company attorneys said in a recent court hearing on the cleanup progress that in-situ also solved access issues posed by pumping water and finding a place to put it, and was least disruptive to neighbors.

The meeting was sponsored by the City of Ann Arbor, Scio Residents for Safe Water and Michigan State University's Technical Outreach Services for Communities program to help educate residents about the dioxane cleanup.

Scio Township medical filter maker Pall Life Sciences has been cleaning up groundwater around its Wagner Road facility since it bought the company in 1997. Dioxane, a solvent classified as a probable human carcinogen, was used at the facility for two decades until the mid-1980s, when it was detected in lakes and wells in the area.

The MSU program has an agreement with the City of Ann Arbor and Scio Residents for Safe Water to provide assistance on the dioxane cleanup issue.

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