Project Highlights

Soil Vapor Extraction Significantly Reduces Contaminant Concentration in First Six Months



EIS designed, installed, and is currently operating a soil vapor extraction (SVE) system to remediate a former gasoline underground storage tank (UST) site in Santa Cruz County. Due to the historic significance of the on-site building, the gasoline contaminated site soils beneath the building could not be remediated by conventional excavation.


EIS designed a SVE system with air sparging components to mobilize the contaminants in both the soil and groundwater media and then extract the contaminant-laden soil vapor for treatment. The system consists of ten air sparging wells and six soil vapor extraction wells for contaminant extraction and three granular activated carbon (GAC) vessels for contaminant treatment. The SVE system was installed with minimal disruption to site usage.


EIS managed the system installation from initial permit applications at Regional Water Quality Control Board, Air District, and County Building, Planning, Health and Fire Departments, through contractor selection, construction observation and project coordination, to system completion. In early 2008 EIS commenced the system start-up and continued with the implementation of an operation and maintenance (O&M) plan


Verification sampling results indicate significant reduction of hydrocarbon contaminant concentrations (up to 75%) in the first six months of the system operation. EIS is targeting achieving site closure status in second quarter of 2009. The client is being reimbursed for all remediation costs by the State UST Cleanup Fund.