Why the technology was selected:
Natural attenuation with monitoring was recommended due to the limited extent and relatively low levels of groundwater contamination.

Date implemented:
Natural Attenuation Monitoring- August 2000

Final remediation design:
Natural attenuation monitoring was conducted at this site for approximately 2 years.

Results to date:
Groundwater at this site had met the requirements for no further action within two years of monitoring. This requirement was met after two consecutive quarters of monitoring, which had concentrations below the regulatory MCLs. Both soil and groundwater had met the requirements for no further action. A Site Rehabilitation Completion Order was issued for this site on October 25, 2002.

Why the technology was selected:
The soil excavation was conducted in order to remove the limited extent of soils exceeding the SCTLs.

Date implemented:
Soil Excavation - March 2002

Final remediation design:
Soils were excavated from beneath the building slab, within the area of the former drycleaning machine. The lateral extent of soils exceeding SCTLs was delineated prior to conducting the excavation. The section of floor slab removed was 6 ft x 8 ft and approximately 10 cubic yards of the underlying soil was removed to a depth of 8 ft bgs. The soils were removed using a vacuum truck

Results to date:
Upon completion of the soil excavation a confirmatory soil sample was collected at the bottom of the excavation. This sample had a leachate concentration of 1.3 µg/L PCE, which is below the MCL. Both soil and groundwater had met the requirements for no further action. A Site Rehabilitation Completion Order was issued for this site on October 25, 2002.

Cost to Design and Implement:
$29,000 (confirmatory soil sampling, excavation and disposal)