Record of Decision Amendment Signed, Cleburn Street Well Superfund Site, Operable Unit 5, Grand Island, Hall County, Nebraska
EPA Region 7 has signed a Record of Decision (ROD) Amendment for the Cleburn Street Well Site, Operable Unit 5 (OU5) in Grand Island, Nebraska. This action is being taken under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), also known as the Superfund law. The ROD Amendment was signed on March 16, 2009.
EPA convened a public hearing on November 13, 2008, to present the Proposed Plan to the local community and receive feedback about the proposal. EPA did not receive any written comments on the proposal. The ROD Amendment is available for review at the Edith Abbot Memorial Library in Grand Island.
The selected remedy in the original ROD included a Soil Vapor Extraction (SVE) system for soil cleanup; an Air Sparging (AS) system for ground water cleanup; monitoring of both media; light non-aqueous phase liquids (LNAPL) removal from ground water; and an institutional control (a Grand Island city ordinance barring drinking water wells in the Cleburn site area).
Construction of the Remedial Action, which included 18 AS wells and 5 SVE wells, was completed in June 2004. The SVE/AS system has operated continuously and performed as expected.
The SVE system has effectively and efficiently removed volatile organic compounds (VOCs), including chlorinated solvents, and LNAPL from the subsurface soil to the water table.
However, a shallow zone of compacted silt and clay-rich soil from the surface to approximately five feet below ground surface (bgs) has not been sufficiently cleaned up by the SVE system, due to high compaction and low soil permeability limiting the ability of the system to pull air through this layer of the soil.
Contaminants of concern (COC) in the soil are primarily tetrachloroethylene (PCE), trichloroethene (TCE), cis-1,2-dichloroethylene (cis-DCE) xylenes, toluene, and ethylbenzene. The highest concentrations of these VOCs were detected at depths of five feet bgs, predominantly in the west central portion where products were stored in aboveground tanks.
AMENDED REMEDY DESCRIPTION
The selected remedy enhances the current remedy (Soil Vapor Extraction and Air Sparging Systems) and includes:
- Excavation and thermal desorption of the contaminated shallow soil (4 to 5 feet) in the west parcel of the site.
- Reducing the concentrations of soil COCs to concentrations within the site-specific closure requirements.
- Meeting federal and state standards, requirements, criteria, or limitations that are determined to be legally Applicable or Relevant and Appropriate Requirements.
- Restoring site grade and surfacing to preconstruction conditions using the thermally treated soil and new soil if necessary.
EPA believes that the selected remedy will appropriately address the potential risks to human health and the environment. This remedy is selected due to the remaining soil contamination that was not treated under the remedy selected in the original ROD.
The ROD Amendment is included in the Administrative Record compiled for the site and is available during regular business hours at the following locations:
Edith Abbott Memorial Library
211 N. Washington St.
Grand Island, Nebraska
EPA Records Center
901 N. Fifth St.
Kansas City, Kansas
If you have questions about the meeting or need additional information, please contact:
Community Involvement Coordinator
Office of Public Affairs
EPA Region 7
901 N. Fifth St.
Kansas City, KS 66101
913-551-7598, Toll free: 1-800-223-0425