The site is located at 1904 Summit Avenue in Hastings West Industrial Park on the southwestern outskirts of Hastings, Nebraska. Between 1978 and 2002, the Dana Corporation utilized chlorinated solvents, including tetrachloroethene (PCE), during manufacturing processes at its Hastings facility.
In 1997, a sample from Hastings Municipal Well No. 13, located approximately 800 feet south-southeast of the former Dana Corporation facility, contained PCE at 17 micrograms per liter (µg/l). The Safe Drinking Water Act maximum contaminant level (MCL) for PCE is 5 µg/l. The well was subsequently taken off-line. Municipal Well No. 14, located approximately 1 mile east-southeast of the former Dana Corporation facility, was found to contain 7.3 µg/l of PCE in 2004. Other commercial and private wells in the vicinity have been found to contain PCE above the MCL.
Numerous on-site investigations have been completed at the former Dana Corporation facility between 1998 and the present, including a Preliminary Assessment/Site Investigation completed by the Nebraska Department of Environmental Quality in June 2005.
The general objective of the action is the U.S. Environmental Protection Agency’s (EPA’s) assumption of the operation of existing soil vapor extraction (SVE) and groundwater extraction systems. Activities included in this action will include assessment of the systems – including enhancements or system modifications, scheduled sampling to determine efficiency and effect, operational costs of the systems (i.e., electricity, gas, and water), and daily systems checks.
Between July 2006 and March 2007, the removal program has conducted the following activities:
— Continued quarterly sampling of the monitoring well network.
— Installed a new pump and hydrant (for sampling access) to extraction well RW4 (October 2006).
— Installed a discharge pipe from the treatment building (housing the SVE) to an on-site pond (November 2006).
— Installed an air stripper to treat the groundwater from the four extraction wells (RW1-RW4). Also disconnected the catalytic oxidation and scrubber from the SVE system as levels of contaminants were below NDEQ regulations and maintenance of the scrubber had become an issue (February 2007).
— Excavated sediment from on-site pond to augment recharge to the underlying aquifer (March 2007).
— Initiated groundwater extraction system so groundwater is now being treated with the air stripper, and the treated water is pumped to the on-site pond.
From the removal program's perspective, the site is on a maintenance program. Regular sampling of the monitoring network, SVE, and groundwater extraction system will continue.
The remedial program will conduct field work this summer to more fully characterize the extent of contamination as part of the RI/FS. That data will be utilized to determine whether additional extraction wells are needed. In addition, the pond may not have the capacity to continually receive the treated water. In that event, an injection well may be required.