February 2019 Meeting

Monday, February 11, 2019
6:00 - 7:30 pm

Pellissippi State Technical Community College
10915 Hardin Valley Road, Knoxville
J.L Goins Administration Building
Faculty/Staff Dining Room


SSIs and ASDs, A Piece of the Puzzle Versus the Whole Story


Dr. Konrad W. Quast
Wood, 2030 Falling Waters Road, Suite 300, Knoxville, TN 37922


Recent regulatory changes have increased the amount of groundwater characterization required for Coal Combustion Residuals (CCR) impoundment sites, but it may not be enough to tell the whole story. The determination of a statistically significant increase (SSI) is the first piece of the puzzle and starts the process of unravelling the story. To understand the meaning of an SSI and develop a sound alternate source demonstration (ASD), if feasible, requires additional evaluation. All the constituents and parameters associated with CCR SSIs are also naturally occurring and several are sensitive to pH and redox conditions. Many CCR sites also reside within complex geologic settings where multiple lithologies and intermittent river flooding may be involved. Thus, an SSI can implicate a potential release on its own, but when placed into the context and story of the site hydrogeochemical system, may just be a part of the natural system.

Often, data is collected with regulatory goals in mind. That is collection of specific constituents listed in Appendix III and IV tables of the CCR rule, or state regulatory guidelines are the focus. However, some sites will likely require supplemental data collection to support whether an SSI is related to the CCR unit or part of the natural surrounding system, and that data will need to be incorporated into a site-specific conceptual site model to tell the story of the system. Collection of site-specific supplemental hydrostratigraphic and geochemical data is critical and should be tailored to the SSI and hydrogeochemical system being assessed.


Dr. Quast has over 20 years of diversified hydrology and geochemistry experience including managing technical teams, providing expert witness testimony, interpretation and evaluation of data to define basin wide geochemical processes, contaminant migration, groundwater recharge, groundwater flow, groundwater surface water interaction, natural gas origin, and oil and gas water production and management. Recent and ongoing experience includes development of numerical fate and transport groundwater models for CCR impoundment impacts and remedial options assessments, and of the former Pease Air Force Base in NH for the U.S. Air Force Civil Engineer Center (AFCEC) in support of remedial options assessment and design related to per- and polyfluoroalkyl substances (PFAS) groundwater contamination.



Page updated February 11, 2019