Tetra Tech has been under contract to the Air Force Center of Environmental Excellence (AFCEE) since 1992 to assess the effects of past waste management practices on the regional groundwater quality at March Air Force Base and surrounding communities.

Tetra Tech is responsible for the basewide groundwater modeling program at March Air Reserve Base. Tetra Tech effectively integrated a variety of hydrogeological information into a revised and more targeted conceptual model of March AFB’s groundwater fate and transport. Groundwater flow and transport modeling has been conducted to address regional, basewide, and site-specific issues.

The basewide flow model was used to design the base boundary containment system to prevent offbase migration. The basewide and site-specific transport models supported natural attenuation and design of the monitoring program for the offbase and specific sites’ groundwater plumes. The regional flow model was used to evaluate the potential entrainment of the offbase plume into municipal supply wells. A chemical transport model was also constructed to estimate the future fate of the TCE plume, and evaluate source release scenarios to assess its historical migration. The TCE transport model demonstrated that the offbase plume areas undergoing natural attenuation would not significantly impact nearby municipal water supply wells. Based on the particle tracking evaluation, the location of additional extraction wells was recommended to enhance plume containment.