Integrating the Geochemical Conceptual Site Model and Advanced Statistics Evaluate Remedy Response and Prepare for Adaptive Management

Integrating the Geochemical Conceptual Site Model and Advanced Statistics Evaluate Remedy Response and Prepare for Adaptive Management

Grand Rapids, Michigan

Integrating the Geochemical Conceptual Site Model and Advanced Statistics to Evaluate Remedy Response and Position for Adaptive Management Authors Ms. Shannon Zahuranec - United States - Life Cycle Geo, LLC Dr. Allie Wyman-Feravich - United States - Life Cycle Geo, LLC Mr. James Jonas - United States - Life Cycle Geo, LLC Dr. Tom Meuzelaar - United States - Life Cycle Geo, LLC Abstract As the utility industry progresses from evaluation of coal combustion residual (CCR) groundwater for corrective action towards implementation of the selected remedy, the focus of monitoring activities shifts from groundwater characterization to remedy performance. A generalized conceptual site model for groundwater beneath CCR units includes a geochemical gradient between the CCR porewater and the site boundary wherein the gradient represents a series of oxidation-reduction (redox) and acid-base (pH) reactions reflecting interactions between the porewater-influenced groundwater and alluvial sediments. Source control activities upgradient of the CCR unit can also affect these reactions occurring beneath and downgradient of the CCR unit. These geochemical reactions can consequently can contribute to both mobilization and attenuation of constituents. This presentation will explore how downgradient groundwater quality responds to various source control and remedial measures. Fundamental geochemical principles, geochemical modeling, and publicly available empirical data will be used to illustrate how different remedial approaches and site conditions affect the conceptual site model. The use of multivariate statistical analyses to evaluate groundwater response to changing geochemical conditions will be discussed in the context of preparing for effective monitoring and adaptive management of remedial systems.