Terraphase was engaged by the city of Torrance in California to investigate soil, soil vapor, and groundwater impacted with chlorinated volatile organic compounds (CVOCs) at a large commercial site in Southern California. The site had a long history of industrial operations, including large-scale degreasing processes at multiple locations.
Scope of Services
Terraphase developed and implemented a focused soil, soil vapor, and perched and regional groundwater investigation to characterize and delineate the nature and extent of trichloroethene (TCE), tetrachloroethene (PCE), 1,1,1-trichloroethane (1,1,1-TCA), and 1,1-dichloroethene (1,1-DCE) impacts from past industrial operations. The project included advancement of soil borings, installation of monitoring wells and multi-depth soil-vapor probes, and coordination with key stakeholders, including multiple commercial tenants, the Federal Aviation Administration (FAA), and airport management, due to some investigation work in proximity to active runways.
The investigation involved advancing over 60 soil borings—many exceeding depths of 100 feet below ground surface—using a membrane interface hydraulic profiling tool (MIHPT) tool to characterize soil and groundwater impacts. Additionally, 14 multi-depth soil-vapor probes were advanced to 85 feet below ground surface, with over 60 soil-vapor samples collected. The investigation included the collection of 40 grab-groundwater samples, and the installation of 8 groundwater monitoring wells. Several of the investigated areas were on airport property, requiring runway closure and night work. The investigations were performed to more precisely define the extent of CVOC impacts; design remedies for soil, soil vapor, and perched and regional groundwater; and support the development of removal and remedial action work plans.
Notable Accomplishments
- Advanced 60 borings across commercial and airport properties, while navigating tenant, regulatory, and airport requirements
- Employed state-of-the-art techniques for sample collection
- Collected quality data in challenging work conditions
- Generated a large dataset to support removal action and remedial action planning
