Weber, Hayes & Associates
120 Westgate Drive
Watsonville, CA 95076
Ph: (831) 722-3580
Fax: (831) 722-1159
DETAILED MTBE DELINEATION AND CLEANUP
Project: Multi-level aquifer characterization and groundwater cleanup for MTBE release into regional aquifer Client: State Water Resources Control Board,UST Cleanup Fund Location: Los Osos,San Luis Obispo, CA
Project Description:
A large MTBE plume in groundwater has impacted the deeper regional aquifer and forced the shutdown of a municipal water production well. Weber, Hayes and Associates (WHA) was selected for site characterization, cleanup and public reporting. Using state-of-the-art tools including sonic drilling, cone penetrometer testing, surface geophysical search for abandoned wells, and the installation of a network of 10 multi-level monitoring wells with over 60 individual sampling points, WHA completed the mapping of the subsurface impact to 3 layered aquifer units. A second gasoline release source was discovered and excavated due to this subsurface investigation. Results of the work have been presented at public meetings and to the Los Osos MTBE Interagency Work Group. A Corrective Action Plan evaluated MTBE cleanup alternatives. WHA designed a multi layer clean-up system, incorporating Soil Vapor Extraction, sparge, groundwater pumping, horizontal boring beneath a shopping center, and O2 release into groundwater for biostimulation. The first two stages of the clean-up system have been installed and aquifer remediation has begun at the site.