Projects

Sierra West conducted groundwater investigations and pilot studies, prepared a feasibility study and final remedy design, and constructed environmental remediation systems for MTBE impacted groundwater and soil. Impacted groundwater was detected in two of five water bearing geologic zones and migration occurred in two distinct directions. A nearby municipal water supply well was impacted by MTBE, thereby increasing the urgency of developing a suitable environmental remediation solution at a site with ongoing litigation between oil companies, the former property owner, and the local water supply company.

An industrial company owns and operates approximately 100 groundwater extraction wells ranging in flow capacity from 10 gpm to over 500 gpm. Five of these wells, located downgradient from the former White Rock North Dump landfill, experienced significant biological fouling. Sierra West performed preliminary investigation evaluations to understand the nature of the biological growth, and then designed and constructed a chemical addition system to prevent future fouling of the wells.

Reviewed existing site data and prepared the Revised Corrective Action Plan, based on new site information. Designed and managed a bench scale treatability test with PRIMA Laboratories to evaluate an ozone injection biobarrier for fuel oil in soils and groundwater. Testing apparatus included an aquarium with sand, internal barriers, and injection tubing to simulate groundwater conditions. Results indicated that ozone worked well, but air alone was satisfactory.

Performed hazardous waste abatement and removal activities at 13 separate sites located on United States Forest Service (USFS) properties across the State of California. At six sites, performed testing and abatement of asbestos containing materials (ACM) including transite pipe, exterior siding panels, interior flooring, roofing materials, and windows. At five sites, testing and abatement of lead based paint. ACM and lead paint abatement activities performed in accordance with applicable OSHA and State regulations. Disposal of these hazardous materials performed at appropriate landfill or disposal facility, in accordance with Federal and State regulations.

Performed an initial evaluation of historical site data, and then worked with the Sonoma County Department of Health Services and property owner to select a remedial technology appropriate for implementation at an active service station.

The City of Woodland, using a grant from the State of California Department of Water Resources, contracted LTD Engineering to conduct a surface water feasibility study. The results of this study indicated that an existing partial water right from the Sacramento River was the most viable alternative to bring surface water into the City of Woodland’s water supply system. As part of this study, LTD Engineering contracted with Mr. Bensch to evaluate necessary improvements to the water distribution system.