Third Five-Year Review to Begin, 10th Street Superfund Site, Columbus, Platte County, Nebraska
The U.S. Environmental Protection Agency (EPA) conducts regular five-year checkups, called five-year reviews, on Superfund sites where cleanups have been initiated. These regular five-year reviews are required by the Superfund law [42 U.S.C. Section 9621 (c)] to make sure the cleanup actions continue to protect human health and the environment.
The first five-year review for this site was completed in February 2000, and the second five-year review was completed in September 2005.
The 10th Street Superfund Site is located in the south-central portion of the city of Columbus, Nebraska. In 1983, the Nebraska Department of Health discovered contamination in Columbus' water supply wells. Follow-up sampling detected Trichloroethene (TCE) in four of the municipal wells.
In February 1995, EPA issued a Record of Decision (ROD) upon completion of a Remedial Investigation/Feasibility Study (RI/FS). The ROD called for ground water monitoring with land use restrictions, with a contingency for extraction and discharge to the Loup River if results indicate unacceptable risks.
Ground water monitoring conducted after issuance of the ROD detected elevated concentrations of Tetrachloroethene (PCE) and TCE in a monitoring well that had previously been considered a background well for the site. A subsequent site investigation conducted in the fall of 1998 indicated a major source of PCE and TCE ground water contamination coming from a dry-cleaning facility located over a half-mile upgradient from the original site.
In October 2000, EPA implemented a removal action which included an Air Sparging/Soil Vapor Extraction (AS/SVE) system to address soil and ground water contamination at the upgradient source area.
EPA finalized an interim remedial action ROD in September 2001, which included extraction of contaminated ground water at municipal well W-1, plume interception by extraction wells, treatment and discharge of contaminated ground water, and continued operation of the AS/SVE system.
In the September 2005 final ROD, the final remedy called for continued operation of the ground water extraction and treatment (GET) and AS/SVE systems, limited action for contaminated soils in the other source areas and chemical oxidation in the upgradient portion of the contaminant plume.
Status of Site Cleanup
Currently, the Soil Vapor Extraction portion of the AS/SVE system is still in operation. The Air Sparging portion of the system is currently not in operation because the ground water table is too high. The GET system is still in operation and provides treated water to the Columbus municipal water supply system. Land use restrictions have been implemented at all three source areas. Regarding chemical oxidation, seven rounds of injections have been conducted in various places within the contaminant plume on a semi-annual basis, starting in January 2007 through October 2009. No further chemical oxidation injections are planned at this time. Currently, EPA is in the process of reviewing all of the site data to determine what response actions will be necessary in the future. EPA does plan to conduct vapor intrusion sampling in 2010.
The Five-Year Review
The five-year review process includes:
- The review and analysis of existing monitoring data.
- The review of site information.
- The inspection of the site to visually confirm and document the condition of the remedy.
EPA will conduct an inspection of the site as part of the five-year review. Current site information will be reviewed by EPA and the Nebraska Department of Environmental Quality to make sure the remedy continues to be protective.
We encourage the community to tell us about site conditions or any concerns you may have.
A final report will be prepared at the end of the review and will be available at the site information repositories and on the EPA Region 7 Website. The goal is to complete the review and report in June 2010.
Site-related documents provide details of the nature and extent of contamination and the work that has been completed at the 10th Street site. These documents are part of the Administrative Record, available during normal business hours at the following locations:
Columbus Public Library
2504 14th St.
EPA Region 7 Records Center
901 N. Fifth St.
Kansas City, Kansas
Questions or requests for information can be submitted to:
Community Involvement Coordinator
U.S. EPA Region 7
901 N. Fifth St.
Kansas City, KS 66101
Toll free: (800) 223-0425