April 3, 2013 Katherine A. Woodward, PE, Project Manager United States Environmental Protection Agency 5 Post Office Square, Suite 100 Mail Code OSRR07-2 Boston, MA 02109-3912 RE: Randolph Substation PCB Remediation Randolph, VT Dear Ms. Woodward: Green Mountain Power Corporation (GMP), formerly Central Vermont Public Service Corporation, has prepared the enclosed PCB Remediation Completion Report for the Randolph Substation site located in Randolph, Vermont. This report was prepared to document remedial and confirmatory sampling activities related to the removal of PCB-impacted material at the site as required by 40 CFR §761 and further specified in the USEPA Region 1 March 27, 2012 PCB cleanup and disposal approval letter. This report and appendices provide the information required by Condition 20 of the approval letter. Please contact me at [email protected] or 802-747-5594 if you have any questions or comments regarding this report. Thank you, Beth Eliason Environmental Engineer Enc. cc: Gerold Noyes, Vermont Department of Environmental Conservation (electronic only) 45 Union Street, Rutland, Vermont 05701 PCB REMEDIATION COMPLETION REPORT RANDOLPH SUBSTATION RANDOLPH, VERMONT APRIL 3, 2013 GREEN MOUNTAIN POWER CORPORATION 45 UNION STREET RUTLAND, VERMONT PCB Remediation Completion Report GMP Randolph Substation Randolph, Vermont EXECUTIVE SUMMARY Green Mountain Power (formerly Central Vermont Public Service Corporation) performed self- implementing cleanup of residual polychlorinated biphenyl (PCB) impacts to soil and concrete at the Randolph Substation to attain the requirements for a high occupancy cleanup consistent with Toxic Substances Control Act (TSCA) regulations in Title 40 of the Code of Federal Regulations at Part 761 (40 CFR 761) Subpart G. Remediation consisted of excavation and off-site disposal of PCB-impacted soils and concrete. The cleanup was performed in accordance with the US Environmental Protection Agency (USEPA) approval and conditions letter dated 27 May 2012 and the Project Work Plan dated December 2012. Soil and concrete excavation and off-site disposal were completed between January 7, 2013 and January 30, 2013. Cleanup consisted of excavation of PCB-impacted soil and PCB-impacted concrete from the substation footprint and excavation of underlying PCB-impacted soil as necessary to attain the remedial goal. Materials and wastes generated during the remediation were disposed of off-site. A total of approximately 239 tons (216,683 kilograms (kg)) of soil and concrete was removed from the Site and disposed of at Waste Management’s TSCA-approved landfill in Model City, New York. Absorbents, personal protective gear, and sampling supplies generated during remedial activities were placed in the trucks departing for the Model City landfill for disposal. Confirmatory soil sampling and analysis in accordance with 40 CFR 761 Subpart O and the conditions of the USEPA approval were conducted at the limits of the excavation. Excavation and materials removal, followed by confirmatory sampling and analysis, were conducted sequentially until the remedial goal of total PCB concentrations less than 1 part per million (ppm) (mg/kg) were attained in confirmatory samples, consistent with the TSCA high occupancy standard. i PCB Remediation Completion Report GMP Randolph Substation Randolph, Vermont Table of Contents 1. INTRODUCTION ................................................................................................................... 1 1.1 Purpose ............................................................................................................................. 1 1.2 Site Description and History ............................................................................................ 1 1.3 Remediation Approach ..................................................................................................... 1 1.4 Remediation Action Implementation ............................................................................... 1 2. REMEDIATION CONSTRUCTION...................................................................................... 3 2.1 Permits and Approvals ..................................................................................................... 3 2.2 Site Preparation ................................................................................................................ 3 2.3 Soil Excavation and Concrete Removal ........................................................................... 3 2.4 Confirmatory Sampling .................................................................................................... 4 2.4.1 Laboratory Analysis .................................................................................................. 4 2.4.2 Excavation Bottom and Sidewall Soil Sampling ...................................................... 6 2.4.3 Concrete Sampling .................................................................................................... 6 2.4.4 Debris Wipe Samples ................................................................................................ 7 2.4.5 Field Quality Control Samples.................................................................................. 9 2.4.6 Laboratory Quality Control Samples ........................................................................ 9 2.4.7 Data Deliverables ...................................................................................................... 9 2.5 Waste Disposal ................................................................................................................. 9 2.5.1 PCB Impacted Soil and Concrete ............................................................................. 9 2.5.2 Decontamination and Solid Waste ......................................................................... 10 2.5.3 Miscellaneous Construction Debris ....................................................................... 10 3. PERIMETER AIR MONITORING ...................................................................................... 10 3.1 Purpose ........................................................................................................................... 10 3.2 Air Monitoring Equipment ............................................................................................. 10 3.3 Action Levels ................................................................................................................. 11 3.4 Results ............................................................................................................................ 11 ii PCB Remediation Completion Report GMP Randolph Substation Randolph, Vermont 4. SITE RESTORATION .......................................................................................................... 11 5. SUMMARY AND CONCLUSIONS .................................................................................... 11 FIGURES Figure 1. Site Location Map Error! Reference source not found.Figure 2. Substation Sampling Layout and Excavation Depths TABLES Table 1. Summary of PCB Verification Sampling Table 2. Summary of Waste Manifests and Disposal Quantities APPENDIX A –Soil and Concrete Laboratory Data Reports and Chain-of-Custody APPENDIX B – Hazardous Waste Manifests and Certificates of Disposal APPENDIX C – Air Monitoring Logs iii PCB Remediation Completion Report GMP Randolph Substation Randolph, Vermont 1. INTRODUCTION 1.1 Purpose Green Mountain Power Corporation (GMP) has prepared this PCB Remediation Completion Report to summarize the remediation activities performed under the PCB self-implementing cleanup and disposal option at 40 CFR §761.61(a) at the Randolph Substation (Site) located on Vermont Route 12 South in Randolph, Vermont for removal of soil and concrete impacted by polychlorinated biphenyls (PCBs). This report provides information required in Condition 20 in Attachment 1 of the March 27, 2012 United States Environmental Protection Agency (USEPA) letter regarding PCB Cleanup and Disposal Approval under §761.61(a). 1.2 Site Description and History The Site is located in a primarily commercial area in Randolph, Vermont (Figures 1). The Site is occupied by a substation, which is over 50 years old and scheduled for modernization. Substation modernization included the removal of all equipment, soil and concrete slabs and foundations from within the existing substation and construction of a larger substation in the same location. 1.3 Remediation Approach The overall remediation approach for PCB-impacted soils and concrete was described by Central Vermont Public Service Corporation (now GMP) in the EPA notification letter dated March 15, 2012 and the Project Work Plan dated December 2012. Substation equipment utilized at this site historically contained PCB oils having a concentration greater than 50 parts per million (ppm). Identified PCB impacts within the substation were likely the result of historic, pre-TSCA releases. Given that the source or sources of the PCB impacts inside the substation are not known, GMP considered PCB concentrations in excess of 1 part per million (ppm) regulated under 40 CFR 761. The overall project objective was to remove soil and concrete with total PCBs concentrations greater than 1 ppm,, dispose of the PCB-impacted materials at a Toxic Substances Control Act (TSCA)-approved disposal facility or a RCRA hazardous waste landfill, and to perform confirmation sampling for PCBs in support of the remedial goal in accordance with 40