Gelman Sciences Dioxane Project;
Ann Arbor, MI

Core Area

HISTORY
Contamination in the Unit C3 Aquifer was discovered in late 1985. Between the years of 1987 and 1994 GSI used a single water supply well located near the property to extract 15,000 lbs of 1,4-dioxane. The contaminated water was injected back into the ground untreated through a deep injection well. The well was installed to nearly one mile deep. It had been originally intended for the discharge of wastewater under a permit issued by U.S.EPA in 1981. In 1994 GSI did not renew the permit due to the maintenance and operating costs of the well. Not renewing the permit halted the operation of 1,4,-dioxane extraction from the aquifer. From 1994 to 1997 the contamination continued to migrate with the groundwater away from the GSI property. Prior to the closure of the reinjection well in 1994, GSI proposed a work plan using surface water discharge to the Remediation and Redevelopment Division (RRD). The work plan was approved but due to accommodate local concerns it was never implemented. Instead a second work plan was submitted to the RRD in 1995. This work plan proposes, if feasible, groundwater reinjection. However, expected difficulties with reinjection and the inability to guarantee that the reinjection would not cause further movement of the contamination ruled out any feasibility of reinjection.

LOCATION
The Core Area is defined as the area of the Unit C3 aquifer that is contaminated with 1,4-dioxane exceeding 500 ppb. A portion of the PLS property is situated above the Core Area. The Unit C3 Aquifer is connected to the deeper channelized D2 aquifer which flows northeast to the Evergreen System. The Core Area is also the source of contamination in the Unit E aquifer.

SYSTEM STATUS
There is a total of six extraction wells in the Core Area. These extraction wells are removing about 340 gallons per minute of contaminated groundwater, the water is then treated and released to the Honey Creek Tributary. Remediation of the Core Area is planned to continue until generic cleanup criterion is achieved. Continued monitoring of the site will occur for ten years following the achievement of the cleanup criterion.

Unit C3 (Core Area)
Unit D0 (Western System)
Unit D2 (Evergreen System)
Unit E Aquifer