Initial review of the treatment operations at the Installation Logistics Center, Fort Lewis, Washington

Abstract

An initial review was conducted of the current treatment operations for remediation of groundwater contaminated with trichloroethene (TCE) at the Fort lewis Logistics Center. Results from this review indicate the two pump-and-treat systems are effectively containing the TCE plume within the upper unconfined aquifer (Vashon Drift). However, mass balance calculations show the existing treatment systems alone will not accomplish the remedial action objective of cleaning up the aquifer to drinking water standards within 30 years as specified in the Record of Decision (ROD). This conclusion is based on the estimated mass of TCE at the source term (51,000 kg), the calculated mass of TCE in the aquifer (4,900 kg), and the removal rate of the pump-and-treat systems that currently ranges from 324 to 667 kg of TCe per year. Four areas within the TCE plume have been identified where enhancements could be made to the existing treatment operations. These are, Area 1 -- the vadose zone source, Area 2 -- the saturated zone source, Area 3 -- a containment area down gradient of Areas 1 and 2, and Area 4 -- the remainder of the plume. This report lists several remedial technologies including new and innovative technologies for these fourmore » areas that may help clean up the site to regulatory acceptable levels, shorten the timeframe for cleanup, or significantly reduce currently estimated Installation Restoration program (IRP) life-cycle costs.« less