Congressional District # 07
WAUSAU GROUND WATER CONTAMINATIONEPA ID# WID980993521
Last Updated: January, 2012
Site DescriptionThe Wausau Groundwater site encompasses an area in the northern section of the city of Wausau, Wisconsin, in which the groundwater potentially impacts six of the City Well Field's production wells. the city of Wausau provides drinking water for approximately 35,000 people from groundwater wells, located on both sides of the Wisconsin River. In 1982, three of the wells were found to be contaminated with high levels of volatile organic compounds (VOCs). In 1984, an interim carbon filter system was installed on one of the affected wells until two air strippers could be constructed. The air strippers, installed at the municipal water facility later in 1984, replaced the carbon filters as a long-term solution for providing acceptable drinking water to city residents. Approximately 32,000 people live within a three-mile radius of the site. The Wisconsin River, which bisects the area, is used for commercial and recreational purposes. There are two source areas that are associated with the groundwater contamination at the Wausau Site. The first source is an old municipal landfill, located south of City Well Six on the Marathon Electric property along the west bank of the Wisconsin River. The second source is in the Wausau Chemical facility property, located southwest of City Well Three along the east bank of the river. Soils at both source areas are contaminated with VOCs. The soils in the old municipal landfill are contaminated primarily with trichloroethlyene (TCE), and soils on the Wausau Chemical property are contaminated primarily with tetrachloroethelyene (PCE), TCE, and other VOCs.
This site is being addressed through federal, state, and potentially responsible parties' actions.
Threats and ContaminantsThe groundwater and soil are contaminated with various VOCs. Potential health risks include accidentally ingesting or coming into direct contact with contaminated groundwater, soil, or soil vapors.
An interim record of decision (ROD) to address the groundwater contamination at the site was signed in December 1988 by the United States Environmental Protection Agency (EPA) with concurrence from the Wisconsin Department of Natural Resources (WDNR). A consent decree (CD) was entered in federal court during September 1989. The interim remedy included the installation of an extraction well, located in the southern portion of the west contaminant plume, and a pump and treatment system for discharge into the Wisconsin River. The construction for the interim groundwater treatment system was completed by the potentially responsible parties (PRPs) in October 1990. A comprehensive final ROD was signed in September 1989, and a comprehensive consent decree (CD) was entered in federal court during January 1991. The major additional remedy component of the second CD and second ROD was the construction and operation of soil vapor extraction (SVE) systems at each of the two source areas. Construction was completed by the PRPs, and operation began on the soil vapor extraction systems in January 1994. SVE remediation was completed at the source area on the west bank of the Wisconsin River, with the system being shut down in April 1996. A revised groundwater monitoring program was approved in June 2000. A five-year review was completed in July 2000 and found that the remedy remains protective of human health and the environment. The SVE system at the source area on the east bank of the Wisconsin River operated until it was shut down in 2001. Subsequent soil sampling in 2001 and local quarterly groundwater monitoring completed in 2003 provided confirmation to the shut down of the east bank SVE system in 2001. A second five-year review was completed for the Site in 2005, and found that the Site remedy remains protective of human health and the environment. The review also required an additional deed restriction for the Wausau chemical property, as associated with the shut down of the east bank SVE system. A formal approval for closure of the east bank SVE system was given by EPA and WDNR in September 2007 after a recorded deed restriction dated April 26, 2007 for the east bank Wausau Chemical property was received. The groundwater pump and treatment remedy continues to operate.
Five-Year Reviews for the Site are on-going since the remedy does not allow for unlimited use and unrestricted exposure. The fourth five-year review was completed by EPA and the Wisconsin Department of Natural Resources (WDNR) in April 2010. That review determined that the remedy 1) remained protective of human health and the environment in the short-term and 2) follow-up actions is necessary to address long-term protectiveness. Those actions included the need to review the pumping rates for the extraction wells, to review the effectiveness of the institutional controls, and to prepare a long-term stewardship plan. The actions are on-going. The fifth five-year review is due by March 2015.
ContactsRemedial Project Manager, U.S. EPA
sheri bianchin (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesWAUSAU GROUNDWATER CONTAMINATION
WAUSAU WATER SUPPLY