Metron Super Gas

Site Assessment and Remediation

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.

Prepared a feasibility study that considered several remedies, evaluated associated costs, effectiveness, disadvantages, and impacts to business operations. Based on these criteria, selected dual phase extraction (DPE) with air sparging as the preferred remedy. In May 2013, installed six remediation wells using multiple drill rigs simultaneously to minimize impacts to business.

Contracted DPE equipment operator and supplier, and obtained regulatory approvals and permits from the Bay Area Air Quality Management District and the City of Petaluma. In a phased approach, performed three 30-day DPE events between June 2013 and May 2014, with associated performance and rebound monitoring events conducted during and after DPE operations. Hydrocarbon impacts in source area soils and groundwater have been reduced to levels appropriate for site closure.

Project Relevance

Worked with property owner and regulatory agency to complete groundwater and soil remediation without negatively affecting business operations. Utilized DPE and air sparging to reduce contaminant mass quickly and cost-effectively. Project required air discharge and treated groundwater discharge permits.