Project:
Former Service Station
Bottom Line: Used multiple innovative and traditional technologies to expedite cleanup and achieve site closure to client's satisfaction.
Summary of Project
The site formerly contained an automobile service station with four single-walled steel USTs. Multiple historical gasoline releases created a significant hydrocarbon plume that included NAPL and extended 350 feet downgradient into a residential area. Numerous investigations and remedial actions were conducted including (1) soil and groundwater assessments, (2) groundwater monitoring, (3) source removal activities, (4) soil and groundwater remediation using multiple innovative and traditional technologies, and (5) remediation activities focused on mitigating migration into the residential area. Groundwater was present at 40 feet below grade.
- Conducted a feasibility study and prepared remedial action plans for RWQCB approval for combined vapor extraction and groundwater extraction and ISCO for residual hydrocarbon mass removal.
- Designed, implemented, and completed a free product removal program.
- Designed, installed, and operated an SVE system to remediate vadose zone soil in the source area under an SCAQMD permit.
- Designed, installed, and operated a groundwater pump-and-treat system to control the dissolved-phase plume and prevent further migration into the residential area. Discharged treated water to a storm drain under an NPDES permit.
- Designed, installed, and operated an in-well vapor stripping pilot test to assess the technology’s viability at the site while using existing infrastructure from the groundwater treatment equipment.
- Designed and managed multiple DPE events to remediate localized areas of impacted soil and groundwater.
- Designed and conducted and assessment using membrane interface probes at 21 locations to define residual hydrocarbon mass that required treatment.
- Designed, installed, and operated a 55-point ISCO system to treat residual hydrocarbons remaining after operation of the pump-and-treat system.
- Maintained high on-line performance for the treatment systems while meeting the operating and reporting requirements of the RWQCB and SCAQMD.
- Performed quarterly and semiannual groundwater and WDR monitoring as required by the RWQCB.
- Applied for and received case closure from the RWQCB.
- Obtained city and county permits and abandoned 90 remediation and monitoring wells and decommissioned a treatment compound.