VESTRA was contracted to conduct remedial activities of a petroleum hydrocarbon release in 2002. The project required an extensive subsurface investigation involving multiple properties to characterize groundwater contaminants and preferential pathways potentially impacting Salt Creek and a perennial stream located downgradient of the source area adequately.

The project involved the coordination and negotiation of access agreements with neighboring property owners, property transfer, and closure strategy using electron acceptor data and an evaluation of mass flux to calculate degradation rates of hydrocarbon constituents migrating downgradient. Ultimately VESTRA was able to provide a strong argument in 2004 to the Regional Water Quality Control Board (RWQCB) that case closure was warranted without active remediation.

Pine Grove was the first project closed using calculated monitored natural attenuation by the Redding RWQCB office.