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HomeMy WebLinkAboutNC0000272_EPA UST Lead Site Workplan_20230516 INTERIM REMEDIAL ACTION WORK PLAN ADDENDUM FOR REMOVAL OF PETROLEUM-IMPACTED SOILS PACTIV EVERGREEN CANTON MILL CANTON, NORTH CAROLINA EnSafe Project Number 0888834351 Prepared for: pactivw' evergreal Pactiv Evergreen 175 Main Street Canton, North Carolina 28716 May 16, 2023 313 Wingo Way Mount Pleasant, South Carolina 29464 843-884-0029 1 843-8S6-0107 www.ensafe.com ENSAFE creative thinking. custom solutions.° TABLE OF CONTENTS EXECUTIVESUMMARY.............................................................................................................. ii 1.0 ZONE 1 — Aboveground Storage Tanks...........................................................................1 1.1 Zone 1: Proposed Removal Action.......................................................................2 1.2 Zone 1: Area Preparation ...................................................................................2 1.3 Zone 1: Excavation Activities ..............................................................................3 1.4 Zone 1: Confirmation Sampling and Monitoring ....................................................3 1.5 Zone 1: Restoration...........................................................................................3 2.0 Zone 2 — Abandoned Sewer Line and Levee Manhole Cistern Add text..............................4 3.0 Zone 3 — Impacted Soils from the Levee Manhole Cistern to the Seep ..............................5 3.1 Zone 3: Proposed Removal Action.......................................................................5 4.0 Zone 4 — Riverbank Seep..............................................................................................7 4.1 Zone 4: Proposed Removal Action.......................................................................7 4.2 Zone 4: Area Preparation ...................................................................................8 4.3 Zone 4: Excavation Activities ..............................................................................8 4.4 Zone 4: Confirmation Sampling and Monitoring....................................................9 4.5 Zone 4: Restoration...........................................................................................9 5.0 Source Characterization — Multiple Zones ..................................................................... 10 6.0 Data Collection and Reporting ...................................................................................... 11 7.0 References ................................................................................................................. 12 FIGURES Figure 1 Conceptual Site Model Figure 2 AST Containment Bunker Cross-Section Schematic TABLES Table 1 Zone 1: Initial Work Plan Investigative Efforts vs Addendum Actions.......................1 Table 2 Data Zone 2: Initial Work Plan Investigative Efforts vs Addendum Actions...............4 Table 3 Zone 3: Initial Work Plan Investigative Efforts vs Addendum Actions.......................5 Table 4 Zone 4: Initial Work Plan Investigative Efforts vs Addendum Actions.......................7 Table 5 Source Characterization: Initial Work Plan Investigative Efforts vs Addendum Actions.......................................................... 10 APPENDICES Appendix A Health and Safety Plan EXECUTIVE SUMMARY EnSafe Inc., on behalf of Pactiv Evergreen (PTVE), has prepared this Interim Remedial Action Work Plan Addendum (Work Plan Addendum) to expedite removal of petroleum-impacted soils in the vicinity of the aboveground storage tanks (ASTs) and associated infrastructure at the Canton Mill (Site) in Canton, North Carolina. This Work Plan Addendum is associated with the Fuel Oil Investigation Work Plan (EnSafe, April 2023) which included a supporting Sampling and Analysis Plan and Quality Assurance Project Plan. The document package was submitted to the United States Environmental Protection Agency's (U.S. EPA) and the North Carolina Department of Environmental Quality (NCDEQ) on April 12, 2023, for comment. During a subsequent site visit with U.S. EPA and Pactiv Evergreen on April 18, 2023, and additional correspondence with NCDEQ personnel from the Underground Storage Tank (UST) Division on April 26, 2023, a consensus was reached expressing interest in an accelerated timeline for the removal of petroleum-impacted soils at the Site. This Work Plan Addendum summarizes relevant aspects of the Conceptual Site Model (CSM) based on investigation activities to date and proposes a more aggressive approach to removal actions across the specific zones described in the initial Work Plan (EnSafe, April 2023). A forthcoming site-specific Health and Safety Plan (HASP) will be modified accordingly for the additional proposed work. The removal action activities proposed within this Work Plan Addendum are presented for review and approval and shall supersede the investigative efforts outlined in the initial Work Plan (EnSafe, April 2023). Pending the results of the analytical data collected during this Scope of Work and consultation with the appropriate agency(s), portions of the original Work Plan may be revised if Site conditions warrant. This project will not commence until the U.S. EPA and NCDEQ approve the additional recommended actions described herein. Rationale and Conceptual Site Model Summation Historical and recent investigations (Law Engineering, February 1995; Roy F. Weston Inc, September 1995; EnSafe, March 2023) have indicated the presence of petroleum-impacted soils within specific areas or zones at the Site as outlined in the CSM presented in the initial Fuel Oil Investigation Work Plan (EnSafe, April 2023). Historically, No. 6 Fuel Oil was stored in 210,000- and 500,000-gallon ASTs in a single containment bunker on the south side of the facility, on the east bank of the Pigeon River. Evergreen has indicated that in 2018, No. 6 Fuel Oil was removed from the 500,000-gallon AST and replaced with No. 2 Fuel Oil (dyed diesel). Currently, No. 2 Fuel Oil continues to be stored in the 500,000-gallon AST and No. 6 Fuel Oil is stored in the 210,000-gallon AST. Plans are now in place to decommission and remove the ASTs and related infrastructure beginning in early June 2023 to coincide with the closure of the Mill. The timely removal of the ASTs and increased accessibility post Mill closure will allow for more immediate implementation of Removal Actions. At this time, in lieu of the assessment activities outlined in the initial Work Plan, PTVE proposes to begin excavation and disposal of petroleum-impacted soils as soon as practical pending the removal of the ASTs. Removal actions will initially focus in zones where impacted soils are present based on previous investigations and the current CSM as depicted in Figure 1. Pursuant to the current CSM, residual fuel oil is likely present in the soil matrix beneath the AST containment bunker and proximal to PZ-16. It also appears that fuel oil and groundwater infiltrate and migrate along an abandoned sewer line that extends northwest from the ASTs, parallel to the protection levee, and terminates at the levee manhole cistern roughly 400 feet northwest. Mobile fuel oil has not been identified in recovery wells RW-6 and RW-7,along the path of the abandoned sanitary sewer line. The absence of mobile fuel oil in these recovery wells suggests that impacts due to residual fuel oils are limited, and that the abandoned sewer line or immediate, adjacent fill is most likely serving as a pathway for fuel oil migration. Further, this CSM presumes the migration of fuel oil from the levee manhole cistern, beneath the access road and ultimately to the seep, likely occurred within/along the abandoned lines emanating from the levee manhole cistern, and within the adjacent, highly-permeable cobbles, as observed in pits dug along the access road. Tables 1 through 5 in the following text were derived from the initial Work Plan and have been revised to summarize the interim removal actions to be implemented in lieu of further investigative efforts for each of the respective zones. Though many of the investigative efforts outlined in the initial Work Plan (italicized in tables) will be superseded by removal actions, further monitoring may be required pending results of confirmatory soil data. Any further actions deemed appropriate should be consensus-driven among the applicable stakeholders. iii Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 1.0 ZONE 1 —ABOVEGROUND STORAGE TANKS Hydrocarbon-impacted soils at the Site were first evaluated during assessment activities in the early 1990s. Prior reports document the presence of hydraulic oils in the soils proximal to the ASTs and heavy fuel oil within the gravel base in the northeast corner of the containment bunker prior to installation of a concrete floor (Law Engineering and Environmental Services, February 1995). In 1995, monitoring well PZ-16 was installed just north of the AST containment bunker to gauge the presence/absence of free product; no evidence of mobile fuel oil in soil or impacts to groundwater were identified at that time (Weston, September 1995). An unknown petroleum hydrocarbon was first identified in PZ-16 in 2013 as part of routine long-term monitoring for a separate black liquor seep response action. The free product was reported to NCDEQ in a letter from PTVE to NCDEQ (Evergreen, February 2013), and it was determined that this material was residual from a prior release. The letter concluded that, based on the construction specifications of bin walls within the levee structure that extend nearly 10 feet below the riverbed in that location, the potential for migration to the river was low. Fuel oil was first observed in PZ-16 in 2018 during long-term, semi-annual monitoring events associated with the black liquor response action, and on a continuous basis since 2018 (AECOM reports, various dates). Furthermore, remote camera footage appeared to show fuel oil infiltrating an abandoned sewer line that runs beneath the AST bunker and proximal to PZ-16 during recent investigative efforts. A cross-section schematic from the AST containment bunker to the Pigeon River is displayed as Figure 2. Table 1 below summarizes the revisions proposed in Zone 1. Table 1 Zone 1: Initial Work Plan Investigative Efforts vs Addendum Actions Initial Work Plan vs Addendum Status of Initial Resolution vs Addendum Omissions from Initial Work Plan Collect soil samples from five proposed boring locations to further Zone 1: delineate fuel oil and other hydrocarbon impacted soils near the AST containment bunker and PZ-16. Initial Work Plan Data Gap: Extent of residual These data will be used to gauge the potential for supplemental actions product/impacted media proximal to ASTs /n source/release areas. unknown. Sample intervals per Table 4-2 in the SAP Addendum 0 4-5 feet bgs Forego investigative soil borings and • 9-10 feet bgs implement Removal Action of impacted soils • 14-15 feet bgs within and proximal to the footprint of the former AST bunker. Delineation of impacted Addendum soils will be based on field observations. Collect confirmatory soil samples from each excavation wall and a representative sample from the base of each excavation. I Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 Table 1 Zone 1: Initial Work Plan Investigative Efforts vs Addendum Actions Initial Work Plan vs Addendum Status of Initial Resolution vs Addendum If warranted, based on confirmatory sample data, install up to two monitoring wells into the cobble layer in select locations to monitor groundwater quality. Soil and Groundwater Samples will be analyzed by U.S. EPA Method 8015 and MADEP EPH Methods pursuant to the QAPP. Notes: AST = aboveground storage tank SAP = Sampling and Analysis Plan bgs = below ground surface U.S. EPA = United States Environmental Protection Agency QAPP = Quality Assurance Project Plan NAPL = non-aqueous phase liquid 1.1 Zone 1: Proposed Removal Action As noted above, fuel oil is present in the soils around and beneath the AST bunker to an unknown extent. This residual fuel oil serves as the source of the seep via migration observed within abandoned sewer structures. The recent announcement that the ASTs and other fuel oil-related infrastructure was to be decommissioned and removed at the time of the Mill closure in June of 2023 was seen as opportunity to forgo some investigative efforts and focus on removal actions. The proposed soil removal actions outlined below should commence once the AST and associated equipment have been removed. A HASP (included as Attachment A) has been developed and updated to address specific safety protocols for each potential work zone during removal activities at the Site based on the anticipated activities and the historical contaminant data documented during past investigations. Employees working on the Site will be required to review and comply with the HASP along with any site-specific requirements. The removal contractor will be required to be HAZWOPER Technician-certified. Work zone-specific requirements will be added to the HASP as needed. 1.2 Zone 1: Area Preparation Prior to implementation of removal actions in Zone 1, a safety meeting will be held to confirm that conditions are suitable to begin the excavation of impacted soils and to determine operational areas for the heavy equipment required for the excavation. It is anticipated that most heavy equipment should avoid encroaching on the outer areas of the protection levee near the river where the two bin walls are located. The HASP will be reviewed, and personnel will be briefed on the chemicals of concern, emergency response actions, stop work authority, and the potential hazards present. 2 Interim Remedial Action Work Plan Addendum for Removal of Petroleum Impacted Soils MSA Par Evergreen Canton Mill Site—Canton, North Carolina May 16,2023 1.3 Zone 1: Excavation Activities After Site preparations have been completed, a long-arm excavator and/or other suitable equipment will be utilized to remove impacted soils from Zone 1. Given that the fuel oil at the Site is visible within the soil matrix when present, and nearly immobile, removal efforts can be driven by field observations. Collection of impacted soils will begin beneath the AST containment bunker and continue laterally and vertically until residual fuel oil is no longer encountered or site conditions warrant otherwise. Soils not visibly impacted (clean overburden) will be stockpiled nearby for use as potential backfill. The excavator will likely be positioned in the area currently occupied by rail cars. To assist the excavator, a compact track loader (or similar equipment) will be utilized in consolidating material for removal by the excavator among other tasks. The long-arm excavator will remove material from the excavation area and place it into a dump truck equipped with a sealed dump bed gate. Impacted soils will be transported to a secure area onsite where it can be contained, staged in piles, and potentially sorted. Larger materials (i.e.: boulders/cobbles) that exhibit staining may be segregated from the impacted finer-grained material and repurposed. Precautions will be made to ensure no material is lost between the removal area and staging areas. Any material collected at or below the water table or otherwise saturated will be allowed to dewater in a suitable containment vessel in the staging area. Water produced from dewatering activities will be collected within a sump and removed accordingly. Excavated soils will be sampled for waste characterization. Once analytical results have been received, the impacted soils will be placed into lined dump trucks for offsite disposal at an approved facility. If impacted material does not dewater as expected, the use of dewatering roll-off boxes may be required. 1.4 Zone 1: Confirmation Sampling and Monitoring Once removal actions are deemed complete by field teams, confirmatory soil samples will be collected from each excavation sidewall and base for analysis. Analytical methods for soil samples are outlined in the original QAPP (EnSafe, April 2023). Pending the results of the analytical data, if warranted, portions of the original Work Plan may be enacted after consultation with the appropriate agency(s). 1.5 Zone 1: Restoration Restoration plans for this Zone have yet to be finalized and will likely remain so until data indicates remedial efforts are complete. 3 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 2.0 ZONE 2—ABANDONED SEWER LINE AND LEVEE MANHOLE CISTERN In accordance with the CSM, any residual fuel oil present in Zone 2 is likely confined to the soils immediately adjacent to the abandoned sewer structures. The absence of product in recovery wells RW-6 and RW-7 along the route of the abandoned sewer lines further suggests that significant migration of product has not occurred in this locale and is consistent with the physical characteristics of residual heavy fuel oils. Extensive interim removal actions may not be warranted in Zone 2 unless excavations from contiguous zones indicate recoverable quantities of impacted soils are present in this zone. Should Zone 2 require immediate removal action, the protocols from sections 1.1 through 1.5 will be followed; however, the excavator will need to be relocated accordingly. Table 2 below summarizes the revisions proposed in Zone 2. Table 2 Data Zone 2: Initial Work Plan Investigative Efforts vs Addendum Actions Initial Data Gaps vs Proposed Action Status of Initial Resolution vs Addendum Omissions from Initial Work Plan Collect soil samples from up to three proposed boring locations to further delineate fuel oil and other hydrocarbon-impacted soils along the ZONE 2: route of the abandoned sewer line. Initial Work Plan Existing recovery wells RW-6 and RW-7 are positioned along the Data Gap: Extent of residua/ abandoned sewer and will serve as monitoring points for the evaluation product/impacted media proximal to of groundwater quality proximal to the abandoned sewer line. abandoned sewer line and levee manhole cistern Sample intervals per Table 4-2 in SAP Addendum 9-10 feet bgs 14-15 feet bgs should excavations from contiguous zones indicate recoverable quantities of impacted Addendum soils are present in Zone 2, immediate If warranted, collect confirmatory soil samples from each excavation removal actions may be taken. wall and a representative sample from the base of each excavation. If Zone 2 requires immediate action, Existing recovery wells RW-6 and RW-7 are positioned to allow for the delineation and removal of impacted soils will monitoring groundwater quality in Zone 2. be based on field observations. Soil and groundwater samples will be analyzed by U.S. EPA Method 8015 and MADEP EPH Methods pursuant to the QAPP. Notes: SAP = Sampling and Analysis Plan bgs = below ground surface U.S. EPA = United States Environmental Protection Agency QAPP = Quality Assurance Project Plan MADEP EPH = Method for the Determination of Extractable Petroleum Hydrocarbons 4 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 3.0 ZONE 3 — IMPACTED SOILS FROM THE LEVEE MANHOLE CISTERN TO THE SEEP Oil was observed in three of the four test pits that were excavated in February 2023, along an access road between the Pigeon River and the base of the protection levee utilizing a HydroVac system. The presence of oil was noted in a cobble horizon in Pits 2, 3, and 4 at depths of around 3.5 feet below ground surface. The presence of fuel oil residuals in the alluvium (sands, gravels, and cobbles) beneath the access road at the base of the levee appear to be associated with two abandoned sewer lines emanating from the levee manhole cistern. The current CSM presumes that any migration of heavy fuel oil that occurred from the levee manhole cistern toward the access road, and ultimately the seep, likely occurred within or along the two abandoned pipes and/or within the highly-permeable cobble horizon observed in the base of the test pits. The two sewer lines were plugged by PTVE at the levee manhole cistern in August 2022. Table 3 below summarizes the revisions proposed in Zone 3. Table 3 Zone 3: Initial Work Plan Investigative Efforts vs Addendum Actions Initial Data Gaps vs Proposed Action Status of Initial Resolution vs Addendum Omissions from Initial Work Plan Collect soil samples at three proposed boring locations to further delineate fuel oil-impacted soils between the levee manhole cistern and the seep. Assessments may also be performed using test pits/trenches to gauge recovery options along the access road ZONE 3: If warranted, based on soil borings and samples, one monitoring well may be installed downgradient in Zone 3 into the cobble layer. This well allows for Initial Work Plan monitoring of any product migration between the levee manhole cistern and the Data Gap: Extent of residual product/impacted seep, media between LMC and seep not fully defined. Sample intervals per Table 4-2 in SAP Addendum 0 4-5 feet bgs Forego investigative soil borings and implement • 9-10 feet bgs Removal Action of impacted soils proximal to the access road pit locations between the LMC and the Addendum seep.Delineation of impacted soils will be based on Collect confirmatory soil samples from each excavation wall and a representative field observations. sample from the base of each excavation. If warranted, based on confirmatory sample data, install up to two monitoring wells into the cobble layer in select locations to monitor groundwater quality. Soil and Groundwater Samples will be analyzed by U.S. EPA Method 8015 and MADEP EPH Methods pursuant to the QAPP. Soil and groundwater samples will be analyzed by U.S. EPA Method 8015 and MADEP EPH Methods pursuant to the QAPP. Notes: SAP = Sampling and Analysis Plan bgs = below ground surface U.S. EPA = United States Environmental Protection Agency QAPP = Quality Assurance Project Plan LMC = Levee Manhole Cistern MADEP EPH = Method for the Determination of Extractable Petroleum Hydrocarbons 3.1 Zone 3: Proposed Removal Action 5 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 As discussed above, fuel oil is present in a highly-permeable cobble-laden soil horizon. The presence of heavy fuel oils within the highly-permeable strata is likely acting as the immediate source for the seep along the riverbank. Though the vertical and horizonal extent of the impacted soils is unknown at this time, it is proposed that removal actions begin in this zone in a timely manner once Mill operations cease. Except for excavator repositioning, removal actions in Zone 3 will mirror the protocols set forth in sections 1.1 through 1.5 above. 6 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 4.0 ZONE 4— RIVERBANK SEEP No. 6 Fuel Oil was first observed seeping from the east bank of the Pigeon River on June 3, 2021, approximately 350 feet to the northwest of the AST containment bunker. Initial abatement activities were implemented from June through August 2021, including deployment of oil containment booms, free product recovery, and inspections of the seep area conducted multiple times per week. Flash flooding along the Pigeon River associated with Tropical Storm Fred in August 2021 all but eliminated any residual product along the riverbank. Free product was again identified along the riverbank on August 18, 2022, in roughly the same location as the previous seep in 2021. Unintrusive abatement activities were implemented and have continued as needed. Table 4 below summarizes the revisions proposed in Zone 4. Table 4 Zone 4: Initial Work Plan Investigative Efforts vs Addendum Actions Initial Data Gaps vs Proposed Action Status of Initial Resolution vs Addendum ZONE 4: Initial Work Plan—no omissions Initial Work Plan Per Initial Work Plan Data Gap: Extent of residua/ Further testing of soil/sediment and surface water will be conducted at product/impacted media and continued 3 collocated locations shown on Figure 7(1 upstream, i downstream, assessment of risks associated with the seep and I at the seep)to aid in determining and implementing appropriate along the east bank of the Pigeon River. toxicity testing methods given NAPL presence and exposure scenario. Addendum Addendum Forego investigative soil borings and If feasible, collect confirmatory soil samples from each excavation wall implement Removal Action of impacted soils and a representative sample from the base of each excavation. proximal to the seep. Delineation of impacted Sediment and surface water samples will be analyzed by U.S. EPA soils will be based on field observations Method 8015 and MADEP EPH Methods pursuant to the QAPP Notes: SAP = Sampling and Analysis Plan bgs = below ground surface U.S. EPA = United States Environmental Protection Agency QAPP = Quality Assurance Project Plan NAPL = non-aqueous phase liquid MADEP EPH = Method for the Determination of Extractable Petroleum Hydrocarbons 4.1 Zone 4: Proposed Removal Action As noted above, fuel oil was observed seeping from the east bank of the Pigeon River and likely derived from free product escaping the levee manhole cistern via two abandoned lines that have since been plugged. The proposed soil removal actions outlined below could commence once the integrity of the current pneumatic piping plugs in place is confirmed or a permanent seal of the lines within the levee manhole cistern is completed. The subsurface extent of the residual fuel oil proximal to the seep is currently unknown; however, excavations within Zone 3, along the levee, and access 7 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 road may provide insight to the volume of impacted media requiring removal from the riverbank. A HASP has been developed and updated to address specific safety protocols for each potential work zone during removal activities at the Site based on the anticipated activities and the historical contaminant data documented during past investigations. Employees working on the Site will be required to review and comply with the HASP along with any site-specific requirements. The removal contractor will be required to be HAZWOPER Technician-certified. Work zone-specific requirements will be added to the HASP as needed. 4.2 Zone 4: Area Preparation Prior to removal actions along the riverbank, additional containment and sorbent boom will be deployed to capture any product or sheen that may be liberated during excavation activities. A response team will be in place to recover any product or sheen observed during removal efforts. Removal efforts within Zone 4 will likely require acceptable, near base-flow, river levels to safely complete this Scope of Work. Silt fencing may be utilized to mitigate the release of unacceptable amounts of fine-grained material into the river, if warranted. Safety meetings will be held prior to the implementation of removal actions to confirm that conditions are suitable to begin the excavation of impacted soils and to determine the limits of operational areas. Notification from the Federal On-Scene Coordinator to the United States Army Corp of Engineers of the removal actions may be required pursuant to the Nationwide Permit 20 as follows: "Activities conducted in response to a discharge or release of oil or hazardous substances that are subject to the National Oil and Hazardous Substances Pollution Contingency Plan (40 CFR part 300) including containment, cleanup, and mitigation efforts, provided that the activities are done under either: (1) the Spill Control and Countermeasure Plan required by 40 CFR 112.3; (2) the direction or oversight of the federal on-scene coordinator designated by 40 CFR part 300; or (3) any approved existing state, regional or local contingency plan provided that the Regional Response Team (if one exists in the area) concurs with the proposed response efforts." Courtesy notification of the proposed removal actions and this Work Plan will also be made to NCDEQ — Water Quality Division, and other applicable stakeholders. 4.3 Zone 4: Excavation Activities After site preparations have been completed, a long-arm excavator and/or other suitable equipment will be utilized to temporarily relocate and stage riprap boulders allowing access to the impacted soils 8 Interim Remedial Action Work Plan Addendum for Removal of Petroleum Impacted Soils MSA Par Evergreen Canton Mill Site—Canton, North Carolina May 16,2023 along the riverbank slated for removal. As with excavations in other zones, removal efforts will be driven by field observations. Collection of impacted soils will begin at the seep and continue laterally and vertically until residual fuel oil is no longer encountered or site conditions warrant otherwise. Soils not visibly impacted (clean overburden) will be stockpiled nearby for use as potential backfill. The excavator will likely be positioned on the access road that runs parallel to the riverbank. A compact track loader (or similar equipment) may be utilized to assist the excavator in removing material among other tasks. The long-arm excavator will remove material from the excavation area and place it into a dump truck equipped with a sealed dump bed gate. Impacted soils will be transported to a secure area onsite where it can be contained, staged in piles, and potentially sorted. Larger materials (i.e.: boulders/cobbles) that exhibit staining may be segregated from the impacted finer-grained material and repurposed. Precautions will be made to ensure no material is lost between the removal area and staging areas. Any material collected at or below the water table or otherwise saturated will be allowed to dewater in a suitable containment vessel in the staging area. Water produced from dewatering activities will be collected within a sump and removed via vacuum truck. Excavated soils will be sampled for waste characterization. Once analytical results have been received, the impacted soils will be placed into lined dump trucks for offsite disposal at an approved facility. If impacted material does not dewater as expected, the use of dewatering roll-off boxes may be required. 4.4 Zone 4: Confirmation Sampling and Monitoring Once removal actions are deemed complete by field teams, confirmatory soil samples will be collected from each excavation sidewall and base for analysis. Analytical methods for soil samples are outlined in the original QAPP (EnSafe, April 2023). Pending the results of the analytical data, if warranted, portions of the original Work Plan may be revisited after consultation with the appropriate agency(s). 4.5 Zone 4: Restoration Restoration of the riverbank to its prior state will commence immediately upon completion of removal activities. Excavations will be backfilled with a similar material and the riprap boulders will then be returned to their original locations to the extent practical. 9 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 5.0 SOURCE CHARACTERIZATION — MULTIPLE ZONES Source characterization does not deviate from the initial Work Plan and is summarized in Table 5 below. Table 5 Source Characterization: Initial Work Plan Investigative Efforts vs Addendum Actions Initial Data Gaps vs Proposed Action Status of Initial Resolution vs Addendum Addendum does not deviate from the Initial Work Plan Per the SAP: Samples of residual product from proposed locations will Source characterization be analyzed (fingerprinted) to determine the hydrocarbon fingerprint MULTIPLE ZONES: proximal to the inferred source (Zone 1) and to document any changes in fuel fingerprint along the migration pathway(Zones 2, 3 and 4). Fingerprint data will be useful in gauging whether there is a difference in distribution/mobile fraction to be considered in the remedial approach. Recommended analysis per the QAPP: Gas Chromatography-Flame Ionization Detection or Gas Chromatography/Mass Spectrometer in full- scan mode. Notes: SAP = Sampling and Analysis Plan QAPP = Quality Assurance Project Plan 10 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 6.0 DATA COLLECTION AND REPORTING During field activities, EnSafe will use the ArcGIS Field Maps application with Global Positioning System to collect pertinent information and observations for each sampling point. Such information will include location coordinates (sub-meter accuracy, to the extent practicable), photographs, sample and analysis data, field note logs, excavation extents, and other pertinent information. At the completion of each phase of work or task, EnSafe will provide updates via the SharePoint Site with all relevant data. Given the unknowns associated with our current understanding of volume and extent of impacted subsurface media, this Interim Remedial Action Work Plan serves as an addendum to the initial Fuel Oil Investigation Work Plan and accompanying Sampling and Analysis Plan, Quality Assurance Project Plan, and Health and Safety Plan, and may require additional amendments to address changing field conditions. 11 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils Pactiv Evergreen MSAFE Canton Mill Site—Canton, North Carolina May 16, 2023 7.0 REFERENCES AECOM. Semi Annual Groundwater Sampling Reports, Pactiv Evergreen Site. Various Dates. EnSafe Inc. Technical Memorandum Summary of Response Actions Pactiv Evergreen Canton Mill, Canton, North Carolina. March 2023. — Initial Work Plan (i.e., Fuel Oi/Investigation Work Plan. Pactiv Evergreen Canton Mill, Canton, North Carolina. April 2023. — Fuel 0// Investigation Quality Assurance Project Plan. Pactiv Evergreen Canton Mill, Canton, North Carolina. April 2023. — Fuel Oil Invest/gat/on Sampling and Analysis Plan. Pactiv Evergreen Canton Mill, Canton, North Carolina. April 2023. — Fuel Oil Investigation Health and Safety Plan. Pactiv Evergreen Canton Mill, Canton, North Carolina. April 2023. Evergreen Packaging. Letter from James A. G/auque to Caroline La Fond, North Carolina Department of Environment and Natural Resources. 2013, February 1. — Letter from James A. G/auque to Caroline La Fond, North Carolina Department of Environment and Natural Resources. 2013, September 10. — Notification of Discharge(Form UST-62). 2021, June 8. — Technical Memorandum, Inc/dent Number 96085, No. 6 Fuel 0// Release Status Update, 2021, November 9. — Technical Memorandum, Inc/dent Number 96085, No. 6 Fuel O/l Release Status Update, 2022, June 6. — Notification of Discharge(Form U5T-62). 2022, August 18. — Communications re: abandoned sewer inspections. January 2023. — Communications re: decommissioning and removal ofASTs. April 2023. 12 Interim Remedial Action Work Plan Addendum for Removal of Petroleum-Impacted Soils MSA North Evergreen Canton Mill Site—Canton, North Carolina May 16, 2023 Interstate Technology & Regulatory Council. 2015. Integrated DNAPL Site Characterization and Tools Selection (ISC-1). Washington, D.C.: Interstate Technology & Regulatory Council, DNAPL Site Characterization Team. www.itrcweb.org/DNAPL-ISC_tools-selection. — Interstate Technology & Regulatory Council. 2018. Light Non Aqueous Phase Liquid (LNAPL) Site Management.' LCSM Evolution, Decision Process, and Remedial Technologies LNAPL-3. Washington, D.C. https://Inapl-3.itrcweb.org. Law Engineering and Environmental Services. Report of Environmental Assessment, Petroleum Contacted Soil at Sites 1-12, Champion International Corporation, Canton, North Carolina M/ll. 1995, February 15. North Carolina Department of Environmental Quality. UST Sect/on Assessment Guidelines, Petroleum and Hazardous Substance UST Releases, Petroleum Non-UST Releases. 2021, January 19. — Comprehensive Tables for Corrective Action Gu/del/nes, Petroleum and Hazardous Substance UST Releases, Petroleum Non-UST Releases. 2021, January 19. — Guidelines for Site Checks, Tank Closure, and Initial Response and Abatement, Petroleum and Hazardous Substance UST Releases, Petroleum Non-UST Releases 2021, May 17. — North Carolina Department of Environmental Quality. 15A NCAC 02C.0108. Effective 2019, September 1. Roy. F. Weston, Inc. Investigation and Remediation at Seven Petroleum Sites, Canton Pulp and Paper Mill, Canton, North Carolina. 1995, September 28. United States Army Corps of Engineers. Nationwide Permit 20 - Response Operations for Oil or Hazardous Substances Effective Date: February 25, 2022; Expiration Date: March 14, 2026 (NWP Final Notice, 86 FR 73522). United States Environmental Protection Agency. Quality System and Technical Procedures forLSASD Field Branches https://www.epa.gov/quality/quality-system-and-technical-procedures-Isasd- field-branches. Last Update 2022, February 7. 13 Figures CONTAINMENT BUNKER �� CONTAINMENT BUNKER MANHOLE - _� 2 SEWER LINE INTEGRITY IS COMPROMISED IN PLACES ZONE 1 BELOWBIN WALLS EXTEND R: PZ-16 PIGEON RIVER J� *PZ-12 RW-7 Q. Q gP ZONE 4 N APPROXIM TE o LOCATIO OF SEEP m OIm ee�F �j<< i S,4A '9ti� RW-6 >� F lGM c LL IF Z c MONITORING/RECOVERY WELL i a ci ABANDONED SANITARY SEWER MANHOLE 0 v cm LEVEE > RIVER FLOW DIRECTION CISTERNANHOLE W FUEL OIL MIGRATION WITHIN ABANDONED SEWER LINE a c m RESIDUAL OIL IN SOILS (OIL EXTENT IN SOIL IS CURRENTLY UNKNOWN. SHADED dAREAS ARE INFERRED FROM 2023 DATA SET) LEVEE LOCATION of FIGURE 1 W UNDERGROUND UTILITIES CONCEPTUAL SITE MODEL >- FUEL OIL DELIVERY LINE FOR ABOVEGROUND STORAGE TANKS PACTIV EVERGREEN CANTON MILL x CANTON, NORTH CAROLINA y ABANDONED SANITARY SEWER(INTEGRITY COMPROMISED IN PLACES)Im REQUESTED BY: TB DATE: 04/26/2023 INFERRED SANITARY SEWER DRAWN BY: KPB PROJECT #: 0888834351 2590 2589' AST - - - - - - - - FILL- 2585 RAILROAD TRACKS - - - - - - 2584' CONTAINMENT WALL 258 2579.7' BIN WALL 7'TOP OF WATER 2575.7' 2575 RIVER 2572.7' 2572.7' a12"OLD SEWER 2570.7' 2570.70' RIVER BOTTOM - - - - - - - - - - - - - - - - - - 2570 O O O O O O O O O O O O O O 256 2565 2565' BIN WALL 3 2561' 2560 G FIGURE 2 CROSS SECTION SCHEMATIC AST CONTAINMENT BUNKER TO PIGEON RIVER LEGEND NOTE REQUESTED BY: TD ���� ALL ELEVATIONS ARE APPROXIMATE DRAWN BY: KMB G WATER TABLE(INFERRED) AST ABOVEGROUND STORAGE TANK 0 0 GROUND SURFACE DATE: 4/28/2023 Creative thinking.Custom solutions. PROJECT: 0888834351 800.588.7962 1..ensafe.com Attachment A Health and Safety Plan