Project Description II

Groundwater Modeling/Chemical Fate and Transport Modeling
Former Pesticide Manufacturing Facility
Central Valley, California

Project Description: The Source Group has recently completed a 3-D fate and transport modeling project at a former pesticide production facility in California utilizing groundwater extraction and treatment to contain a dissolved pesticide plume.

The system consists of over 8 extraction wells pumping over 500 gallons per minute. A 3-D MODFLOW/MT3D model was constructed to simulate the effects of variable pumping scenarios including re-injection of treated water. Modeling was conducted with respect to contaminant migration pathways allowing an assessment of potential future impacts on municipal supply wells.

The objective of this work was to evaluate the effectiveness of the extraction and treatment system currently in place at the Site and provide data supporting a revised remedial program that includes a reduction in total pumping rates.

Results: Based on the results of the modeling, a reduced pumping program was developed that could significantly reduce groundwater extraction rates and associated treatment costs while maintaining adequate hydraulic control.