Chemical Oxidation – Applications in Fractured Bedrock

Presentation Summary: 

Fractured bedrock impacts remain challenging for attaining site cleanup goals in a cost-effective and timely manner. In situ chemical oxidation (ISCO) has been successfully applied in fractured rock settings over the past several years as an alternative to traditional remedies such as groundwater extraction. Remediation of fractured bedrock via ISCO requires a thorough conceptual site model to understand how injected oxidants will transport and disperse in the subsurface. Several case studies will be presented to highlight critical elements of the site model, feasibility testing, and full-scale remedy implementation related to fractured rock applications. Example projects will include petroleum hydrocarbon impacted sites (including MTBE) and chlorinated solvent impacted sites. Oxidants including ozone, hydrogen peroxide, and sodium persulfate as well as other enhancers and their efficacy in these settings will be discussed. Short-term and continuous ISCO remedies and injection methodologies will be evaluated for the remediation of impact in fractured bedrock. Receptors such as potable wells may be present in fractured bedrock settings but not in overburden settings, and can also be impacted at greater distances from the source area. The effectiveness of source area remediation via ISCO with hydrogen peroxide and ozone and the resulting extended dissolved oxygen plume on remediating these receptors will be presented.