Assessment of Corrective Measures Report Ccr Release Incident Ash Valley Refuse/Disposal Area
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ASSESSMENT OF CORRECTIVE MEASURES REPORT CCR RELEASE INCIDENT ASH VALLEY REFUSE/DISPOSAL AREA Prepared for: GenOn Northeast Management Company Conemaugh Generating Station New Florence, PA 15944 Prepared by: Aptim Environmental & Infrastructure, Inc. Pittsburgh, Pennsylvania January 2019 Table of Contents ________________________________________________ List of Tables ................................................................................................................................................................. iii List of Figures ............................................................................................................................................................... iii List of Appendices ......................................................................................................................................................... iii List of Acronyms & Abbreviations ................................................................................................................................. iv 1.0 Introduction ....................................................................................................................................................... 1 2.0 Facility Overview ............................................................................................................................................... 2 3.0 Summary of the Ash Release............................................................................................................................ 3 4.0 Immediate Response Actions............................................................................................................................ 4 4.1 Notification of Release ........................................................................................................................... 4 4.2 CCR Removal ........................................................................................................................................ 4 4.3 Retention of Professional Engineering Services .................................................................................... 4 5.0 Corrective Measures Program .......................................................................................................................... 5 5.1 Initial On-Site Inspection of Immediate CCR Removal Activities ........................................................... 5 5.2 Environmental Sampling Plan Development .......................................................................................... 5 5.2.1 Soil Sampling .......................................................................................................................... 6 5.2.1.1 Overview .................................................................................................................. 6 5.2.1.2 Number of Samples ................................................................................................. 6 5.2.1.3 Location of Samples ................................................................................................ 6 5.2.1.4 Comparison Methodology ........................................................................................ 7 5.2.1.5 Testing Methods for Soil Samples ........................................................................... 7 5.2.1.6 Use of Groundwater Protection Standards .............................................................. 8 5.2.2 Surface Water (Stream) Sampling ........................................................................................... 8 5.3 Review of Pertinent Disposal Site Design Documents .......................................................................... 8 5.4 Correctives Measures Assessment ....................................................................................................... 9 5.4.1 Time Period for Assessment ................................................................................................... 9 5.4.2 Requirements for Corrective Measures ................................................................................... 9 5.4.3 Considered Corrective Measures .......................................................................................... 10 5.5 Public Meeting ..................................................................................................................................... 11 6.0 Sampling Results ............................................................................................................................................ 12 7.0 Recommendation for No Further Action .......................................................................................................... 13 8.0 Certification ..................................................................................................................................................... 14 Tables Figures Appendices Assessment of Corrective Measures Report ii January 2019 CCR Release Incident – Ash Valley Refuse/Disposal Area List of Tables ___________________________________________________ Table 1 Background Soil Sample Results Table 2 Confirmation Soil Sample Results Table 3 Confirmation Leachate Sample Results Table 4 Surface Water Sample Results List of Figures __________________________________________________ Figure 1 Site Location Map Figure 2 Overview of Ash Release Area Figure 3 Soil and Surface Water Sampling Locations (1 of 2) Figure 4 Soil and Surface Water Sampling Locations (2 of 2) List of Appendices _______________________________________________ Appendix A CCR Release Notification to PADEP Appendix B Notice of Time Period Extension for Assessment of Corrective Measures Appendix C Newspaper Advertisement of Public Meeting Appendix D Supporting Soil and Surficial Materials Report Appendix E Analytical Laboratory Reports Assessment of Corrective Measures Report iii January 2019 CCR Release Incident – Ash Valley Refuse/Disposal Area List of Acronyms & Abbreviations __________________________________ APTIM Aptim Environmental & Infrastructure, Inc. CCR coal combustion residuals CCR Rule Disposal of Coal Combustion Residuals from Electric Utilities Final Rule cy cubic yards disposal site Conemaugh Generating Station’s Ash Valley Refuse/Disposal Site ESP Environmental Sampling Plan GenOn GenOn Northeast Management Company GPS global positioning system MCL Maximum Contaminant Level PADEP Pennsylvania Department of Environmental Protection Report Assessment of Corrective Measures Report RRCSP Run-On and Run-Off Control System Plan RSL Regional Screening Level sf square feet SPLP Synthetic Precipitation Leaching Procedure TCLP Toxicity Characteristic Leaching Procedure USEPA U.S. Environmental Protection Agency Assessment of Corrective Measures Report iv January 2019 CCR Release Incident – Ash Valley Refuse/Disposal Area 1.0 Introduction In 2015, the Disposal of Coal Combustion Residuals from Electric Utilities Final Rule (CCR Rule) was enacted within the Federal Register under Title 40 Code of Federal Regulations §257. The CCR Rule establishes technical requirements for coal combustion residuals (CCR) disposal sites and surface impoundments under Subtitle D of the Resource Conservation and Recovery Act, which is the primary law regulating solid waste. Conemaugh Generating Station’s Ash Valley Refuse/Disposal Site (disposal site), operated by GenOn Northeast Management Company (GenOn), is subject to the CCR Rule. On August 8, 2018, a surficial (non-groundwater) release of CCR was discovered during the performance of a routine inspection of the Conemaugh disposal site and established erosion and sedimentation control features. The release most likely occurred during an extremely intense precipitation event on July 30, 2018, which was localized and rare. As described in §§257.84(b)(5) and 257.90(d) of the CCR Rule, in the event of a release from a CCR unit, the owner or operator of a disposal site must immediately undertake necessary measures to control the source(s) of the release so as to reduce or eliminate, to the maximum extent feasible, releases of contaminants into the environment. Additionally, the owner or operator must comply with all related applicable requirements in §§257.96-257.98. For surficial (non-groundwater) spills, these requirements generally include assessing and selecting corrective measures to prevent further releases, remediating the release as necessary, and restoring the affected area to original conditions. To document compliance with the CCR Rule, an Assessment of Corrective Measures Report (Report) must be prepared and placed into the facility’s operating record per §257.96(d) and §257.105(h)(10). This Report must also be noticed to the State Director per §257.106(h)(8) and posted to the publicly accessible internet site per §257.107(h)(8). Conemaugh Station’s responses and subsequent activities to the subject CCR release were in accordance with the above-referenced regulations and guidance from the U.S. Environmental Protection Agency (USEPA) issued in response to a settlement of a portion of the lawsuit challenging the CCR Rule. In the settlement, USEPA agreed to a remand on the issue of defining which non-groundwater releases are subject to the full corrective action process under §§257.96- 257.98. In the interim between the settlement and issuance of a revised regulation (which was not issued prior to this report), for no-groundwater CCR release, USEPA “would recommend that compliance determinations focus primarily on the rapid remediation of detected