Project:
Former Electronics Manufacturing Facility
Bottom Line: Designed, implemented, and operated cleanup of 86,000 cubic yards of ex situ soil and 14 acres of in situ soil to achieve site closure for shallow and deep soil.
Summary of Project
The site formerly contained several structures housing offices, low-level radiation exposure testing, hazardous materials storage, and semiconductor manufacturing. From 1959 to the 1980’s, compounds used or generated at the site included waste solvents and oils stored in five USTs. The site structures were demolished from 1994 through 1996. DNAPL was first encountered in 2003.
- Prepared bid documents and specifications for demolition of onsite facilities. Managed environmental issues during facility demolition including monitoring worker safety, sampling demolished materials, and sampling exposed soil.
- Prepared an RWQCB-approved work plan for surficial soil (less than 15 feet deep).
- Performed soil remediation to expedite property sale and redevelopment. Used a fate-and-transport model to obtain agency approval for increasing the soil cleanup level from 500 to 1,000 μg/kg of total VOCs.
- Excavated about 86,000 cubic yards of surficial soil, including 29,000 cubic yards impacted by VOCs; 6,000 cubic yards impacted by fuel oil; and 51,000 cubic yards segregated, tested, and characterized as non-impacted soil. Transported fuel-oil-impacted soil off site for treatment by low-temperature thermal desorption. Backfilled and compacted non-impacted soil within the onsite excavation.
- Designed, constructed, and operated an aboveground SVE system used to treat the 29,000 cubic yards of VOC-impacted soil in 71 stockpiles to the approved cleanup level.
- Prepared a remedial action plan for deep soil (to 65 feet) remediation using SVE technology. Established soil matrix and soil gas cleanup levels and obtained RWQCB approval for phased cleanup and closure to coincide with property development including subdivision and construction by multiple new owners and tenants.
- Designed, installed, and operated an SVE system to remediate VOC-impacted soil from 12 to 65 feet below grade; system included 26 vapor extraction wells and 18 clustered monitoring wells with extraction by two blowers at 1,100 to 1,800 scfm. Obtained SCAMD permit for offgas treatment by granular activated carbon with onsite steam regeneration.
- Negotiated and obtained approval from the RWQCB for closure of shallow and deep soil remediation of the site’s entire 14 acres; client received letter from the agency specifying “No Further Action.”