SECTION TWO
Operable Unit Background
Based on the findings of the RI, the U.S. Environmental Protection Agency (USEPA), Region V,
the U.S. Department of Defense (DoD), the Ohio Environmental Protection Agency (OEPA),
and the USACE Louisville District negotiated a cleanup strategy and entered into a Federal
facility agreement under Section 120 of CERCLA to address the contamination at LF5. These
parties agreed to address LF5 as a single operable unit (OU) and commissioned a feasibility
study (FS) in March 1993.
REMEDY SELECTION
In a record of decision (ROD) signed in October 1993, the remedy selected for LF5 included:
Treatment of contaminated soils in areas that were suspected sources of groundwater
contamination (soil hot spots) using soil vapor extraction (SVE);
Treatment of contaminated groundwater using air sparging (AS);
Monitoring of the upper aquifer to determine the effectiveness of the selected remedy; and,
Maintenance of institutional controls, including access restrictions.
The groundwater AS system was to operate in conjunction with the SVE system.
The ROD also required that Mn be monitored in the groundwater in the localized areas where
elevated levels were detected during the RI. The ROD specified that, if the results of the
monitoring indicated that levels were not declining, then the need for remediation was to be
reevaluated.
Including limited groundwater extraction and treatment in addition to AS/SVE was considered as
an alternative remedy. However, AS/SVE was determined to be more cost effective than
AS/SVE plus groundwater extraction and treatment while still being protective of human health
and the environment.
The ROD specified four objectives for the remedy:
To prevent exposure to contaminated groundwater;
To restore the contaminated groundwater to its beneficial use (drinking water);
To minimize movement of contaminants from soil to groundwater; and,
To prevent exposure to the contents of the landfill.
No soil cleanup levels were identified. The cleanup levels established for groundwater in the
upper aquifer beneath the site were:
TCE - 5 g/L - the Federal Safe Drinking Water Act maximum contaminant level (MCL);
VC - 1 g/L - the Ohio State Model Toxics Control Act Method B.
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Ft. Griffey Landfill 5 OU Interim RA Report
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