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Huron Valley News

Judge Orders Partial Diozane Remediation

By Ted Sylvester
February/March Issue, 2005

Washtenaw Circuit Court Judge Donald Shelton on Dec. 17, 2004, issued his ruling on how Pall Life Sciences must clean up polluted groundwater in Scio Township and west Ann Arbor. The order is aimed at “Unit E,” a deep underground aquifer where 1,4 dioxane from Pall’s Wagner Road facility has migrated over the years.

The presence of 1,4 dioxane – an industrial solvent classified as a possible carcinogen – was first detected in area groundwater in 1984. Despite some cleanup efforts it was discovered in 2001 that the plume of dioxane-contaminated groundwater had spread into Unit E, farther and deeper than anyone had predicted, and appeared to be encroaching on the city of Ann Arbor and the source of 80% of its water – the Huron River.
In September, Pall and the Michigan Department of Environmental Quality presented proposals and arguments for different cleanup plans to the court.

In his ruling, Shelton rejects the DEQ’s proposal to attack the leading edge of the plume by drilling test- and purge-wells and installing a network of pipes in some west side Ann Arbor neighborhoods. He also rules against a pipeline to carry the treated effluent to the Huron River. Shelton instead chooses Pall’s plan to extract, treat, and re-inject groundwater at a Maple Road facility adjacent to the residential area in an effort to reduce the mass of dioxane that will be allowed to escape and travel through Ann Arbor.

"Additional dioxane to the creek means more risk to Ann Arbor's water supply at Barton Pond and to drinking water aquifers along Honey Creek."

However, Shelton sides withthe DEQ (and other stakeholders) by ordering that Pall must attempt to fully capture the E plume as it crosses Wagner Road. But he requires the DEQ to increase discharge rates to Honey Creek to accommodatethe added purging.

Roger Rayle, co-chair of Scio Residents for Safe Water, has been tracking the controversy since 1993 and following the hearings on this court case from its inception in 2000. Rayle thinks it is proper that Shelton ruled against a leading-edge cleanup that would have meant disruptions to a dense neighborhood without any assurance of effectiveness. However, the ruling failed to address uncertainty about how much dioxane will be left to spread and exactly where it will spread, he points out.

“No one can be sure if the plume will go straight to the river as Pall hopes it will,” he says. “There is inadequate monitoring to know for sure. The plume may spread out or split with some going towards the Ann Arbor water intake at Barton Pond and some going towards private wells on the east side of the city. The modeling to best predict this was rejected by the judge.”

Rayle also has problems with the proposed Maple Road re-injection facility, which will be housed in two construction-type trailers in the Maple Village Shopping Center area. “The judge missed the opportunity to place the treatment system at a nearby, idle commercial property instead of near a busy shopping center and major park,” he says. “The mobile treatment system will use a newer, less expensive, but as yet unproven Ozone-Oxidation technology that may not be as effective as the existing UV-Oxidation technology currentlyused at the core.”

Like Shelton, Rayle thinksPall must attempt to fully capture the E plume at Wagner Road. But Rayle questions whether discharge rates should be raised to accommodate the added purging instead of requiring that Pall use re-injection (like Shelton orders for Maple Road). “Unit E purging will now be added to discharge to the creek even though none of the parties asked for this,” says Rayle. “Additional dioxane to the creek means more risk to Ann Arbor’s water supply at Barton Pond and to drinking water aquifers along Honey Creek.”

For more info. about the Pall cleanup and SRSW, see previous issues of FTGU or visit www.srsw.org.

Ted Sylvester is editor of From the Ground Up.

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