Soil & Groundwater Remediation

Chemical Blending and Bulk Storage Facility
Northern California

The Source Group was retained by a chemical manufacturing and blending company to direct on-going assessment and remediation of soil and groundwater contamination associated with a chemical storage and blending facility in Sunnyvale, California.

Past operations resulted in chlorinated volatile organic compound (VOC) and petroleum hydrocarbon impacts to the subsurface. Soil and groundwater impacts associated with the site included extensive on and offsite soil contamination and a three thousand foot dissolved VOC plume.

Remedial efforts conducted by others had been largely ineffective. The Source Group was retained to develop and implement a revised, comprehensive remedial approach and reestablish a solid working relationship with the California Regional Water Quality Control Board (CRWQCB), the lead regulatory agency.

The Source Group developed, negotiated, and is currently implementing, a comprehensive remedial approach to address soil and groundwater contamination and cap the client's long-term environmental liabilities.

The regulatory approved remedial approach is designed to provide significant contaminant mass source reduction and passive, long-term containment of the dissolved plume.

Based on results of extensive feasibility screening, three key technologies were selected. Enhanced anaerobic biodegradation using "off the shelf" hydrogen releasing compounds and insitu chemical oxidation utilizing ozone with an innovative ozone injection system (patent pending) are being utilized to reduce contaminant sources. An 800-foot offsite permeable reactive barrier utilizing zero-valent iron was also designed and constructed by The Source Group to provide passive, long-term containment of the dissolved VOC plume - preventing the need for expensive groundwater extraction and treatment.

The Source Group was responsible for all aspects of design, permitting, installation, and construction of all remedial systems and will continue to provide onsite operation, maintenance, and groundwater monitoring.

Results: Within two years of taking over the project, The Source Group successfully completed all remedial investigation work to the satisfaction of the CRWQCB.

Remedial investigation activities performed by past consultants spanned over 14 years and failed to adequately delineate the extent of soil and groundwater impacts.

The ineffective groundwater extraction system was taken offline in late 2001, after approximately 8 years of operation, as a result of successful negotiations with the CRWQCB saving the client $15,000 to $20,000 per month in operation and maintenance costs.

As part of regulatory negotiations for approval the remedial approach, The Source Group successfully argued that active remediation of the 2,000-foot dissolved VOC plume (initially required by the CRWQCB) down gradient of the permeable reactive barrier was unwarranted saving the client between $2 million to $4 million dollars over the life of the project.

Utilization of the permeable reactive barrier for containment of the plume will result in reducing long term O&M requirements to groundwater monitoring only. Initial ozone injection effectiveness monitoring results indicate over a 50% reduction in VOCs at monitoring locations.