Remediation of Chlorinated Solvents in Groundwater with PlumeStop: Analytical Challenges and Solutions

In this webinar we are pleased to have a special guest presentation by Richard Desrosiers, Associate Principal and Hydrogeologist at GZA GeoEnvironmental, Inc. In this presentation he discusses cost-effective remediation through enhanced characterization.

An in situ remediation case study is presented to demonstrate how enhanced characterization techniques were used to not only define existing conditions but also to define the upper and lower boundaries of two 4,000-foot plumes. A detailed understanding of subsurface conditions, including the factors influencing migration and natural attenuation, allowed the development of a source zone mass reduction remedial design, followed by a monitored natural attenuation approach for the downgradient portions of the plumes, rather than active remediation of the entire plume.

Stoichiometric doses of PersulfOx (chlorinated plume) and a solution of lactic acid and 3DMe (hexavalent chromium plume) were injected within delineated zones of low and moderate hydraulic conductivity in those high mass zones to effectively reduce contaminant mass. Injection point spacing, and dosing were based on the calculated effective zone of influence of the additive, whereas, treatment barriers were based upon field pilot studies to determine the longevity of the additive and seepage velocities. Current data shows significant plume concentration/mass reductions within the two plumes.