Oklahoma Department of Environmental Quality (ODEQ) prepared a state CCR program which was approved by EPA and became effective on September 15, 2018.
Although the ODEQ program generally mirrors the Federal CCR Rule (40 CFR 257.95 Subpart D), the state rules have been subject to a lawsuit alleging they were unlawfully approved.
While the lawsuit proceeds, ODEQ has begun regulating the Bottom Ash Pond (BAP) at AEP's Northeastern Plant in Oologah, Oklahoma. During assessment monitoring, lithium was detected at statistically significant levels (SSLs) above the groundwater protection standard (GWPS) and an ASD was conducted.
The ASD provided multiple lines of evidence indicating that lithium was naturally occurring and not indicative of a release from the BAP. A hydrogeological investigation helped rule out the possibility that lithium was being sourced from the BAP. A geochemical evaluation suggested there were multiple different groundwater chemistries within the limestone bedrock at the site. Furthermore, the geology of the Site, originally thought to consist of limestone underlain by shale, was determined to consist of a thicker unit of limestone with intermittent shale/clay interbeds. Mineralogical analysis of the shale/clay interbeds identified lithium present in these layers. The presence of lithium and different chemistries in certain monitoring wells appears to generally correlate with the presence of shale interbeds present at and near the screen intervals. These lines of evidence allowed AEP to conclude that an alternate source for lithium at the BAP was naturally occurring lithium dissolved from shale/clay interbeds.
ODEQ did not accept the ASD and requested an assessment of corrective measures. After additional analysis confirmed low concentrations of lithium in the bottom ash pond water and solids, AEP secured approval of the ASD. AEP's experience with the approval process can provide insights to others as more sites become regulated under state programs.
- Geosyntec Authors: Allison Kreinberg
- All Authors: Allison Kreinberg, Geosyntec; Jill Parker-Witt, American Electric Power
- Title: The Utility Solid Waste Activities Group (USWAG) Coal Combustion Residual (CCR) Workshop's Session 1
- Event or Publication: Event
- Practice Areas: Groundwater Assessment and Remediation
- Citation: Allison Kreinberg (Ohio) presented "Approval of an Alternate Source Demonstration Under Oklahoma's State CCR Program" and Lane Dorman, P.G. (Florida) Presented "Case Study: High Resolution Site Characterization (HRSC) to Inform CCR Groundwater Remedial Design and Implementation" at the Utility Solid Waste Activities Group (USWAG) Coal Combustion Residual (CCR) Workshop's Session 1 on June 18, 2020.
- Date: June 18, 2020
- Publication Type: Platform Presentation