Announcing the First Five-Year Review Report for the Ace Services Superfund Site, Colby, Thomas County, Kansas
The U.S. Environmental Protection Agency (EPA) conducts regular five-year checkups, called five-year reviews, on Superfund sites where cleanups have been completed. These reviews are required by the Superfund law [42 U.S.C. Section 9621 (c)]. EPA Region 7 has completed the first five-year review of the Ace Services Superfund site. The site is located at 345 Convesse Ave., Colby, Thomas County, Kansas.
The EPA completed the five-year review in cooperation with the Kansas Department of Health and Environment to make sure the cleanup continues to protect human health and the environment.
Before cleanup began, the site posed a potential threat to public health through contact with chromium-contaminated soils and sludges on the site and consuming contaminated ground water from the Ogallala Aquifer.
Ace Services operated a chrome plating facility on a two-and-a-half acre site from 1954 to 1990. The process they used to apply chrome plating to farm implement parts generated contaminated wastewater. That wastewater went directly on the ground west of the unnamed tributary to Prairie Dog Creek.
The facility eventually installed concrete retention vats and an evaporation lagoon to collect the wastewater. The evaporation lagoon was not lined and chromium contaminated wastewater seeped into the ground, contaminating the ground water.
Chromium-contaminated soil and sludge from the lagoon were removed from the site in 1981. Liquid and solid wastes stored inside the Ace Services facility were removed in 1992. The facility buildings on the site were demolished in 2002.
A city water line was extended to serve residences with affected residential water wells.
Specially installed monitoring wells and existing residential wells were sampled to determine the extent of ground water contamination. To address contamination on the site, extraction wells were installed and a building housing an ion-exchange treatment process to clean the ground water was constructed. The treatment system was declared operational and functional in 2003. The ground water and the treatment system are monitored regularly.
Before the ground water treatment system was constructed, the ground water contamination measured at the site was almost twelve times more than it is now.
The Ace Services ion-exchange treatment system removes contaminants from the ground water and is able to supply up to 51 percent of the drinking water to the city of Colby.
The Five-Year Review
EPA evaluated all available site information to determine if the remedial actions that have been implemented remain protective of human health and the environment.
The results of the first Five-Year Review concluded that the remedial action was protective of human health and the environment and that:
- No known nearby residents are being exposed to contamination.
- The ground water contaminant plume has been reduced by greater than 90 percent within a period of five years.
- Domestic wells located near the site are not adversely affected by the remaining ground water contamination.
- Treated ground water is being beneficially used by the City of Colby in its drinking water supply system. Any discharges of ground water to the City supply system or to the tributary to Prairie Dog Creek are protective.
- Periodic ground water samples continue to be collected and the ground water system extraction rates have been optimized to capture the remaining ground water plume.
- A source area evaluation is being conducted on the site property to determine if any soils remain that may contribute to future ground water contamination.
- The availability of institutional controls and the opportunity for their implementation will be evaluated.
The Five-Year Review Report and the site Administrative Record are available at the following locations during normal business hours:
Pioneer Memorial Library
375 W. Fourth St.
EPA Records Center
901 N. Fifth St.
Kansas City, Kansas
Questions or requests for information can be submitted to:
Community Involvement Coordinator
EPA Region 7
901 N. Fifth St.
Kansas City, KS 66101
Toll free: 1-800-223-0425