Resolved with Sequential ApproachPCE: Triple Threat Take Down
CONTAMINANTS OF CONCERN – PERCHLOROETHYLENE (PCE) AND DEGRADATION PRODUCTS
KEY FACTS – SAND, SOIL, GROUNDWATER, SUB SLAB VAPOR ALL IMPACTED WITH COCs
DESCRIPTION OF SITE – FORMER DRY CLEANER THAT ALSO IMPACTED ADJOINING RETAIL SPACES
A former dry cleaner experienced a release of PCE. AcuityES assessed the nature and extent of PCE and degradation product impacts at the Site, then developed a comprehensive approach to address the triple threat, and remediate the soil, groundwater and soil vapor.
AcuityES used a mobile laboratory to rapidly assess the PCE impacts in the soil and groundwater. Focusing the investigation on source area characterization followed by a downgradient plume evaluation allowed AcuityES to limit the number of permanent monitoring wells to six. AcuityES was able to quickly cut off the leading edge of the PCE plume at the source and successfully complete the Site remediation of all contaminants within three years.
AcuityES treatment protocols successfully completed the Site within three years. Specific actions taken included:
– Soil: 168 tons of soil excavated and disposed off-site removed from the interior and exterior areas of the building.
– Groundwater: 540 gallons of CAP-18 ME (a food grade vegetable oil product) was injected into the saturated shallow aquifer, along with a microbial supplement.
– Indoor Air & Vapor Intrusion: Ventilation ductwork was removed and the former roof-mounted HVAC roof openings were sealed. Epoxy sealant was applied to the floor to minimize VOC migration.
– Ongoing Management of Soil Vapor: Sub-Slab Depressurization (SSD) and Soil Vapor Extraction (SVE) were designed and installed.
– SVE pilot test: A Pilot Test led to reduced treatment area size and volume. The SSD and SVE systems were necessary to manage the long term subsurface vapor issues.