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Home My WebLink AboutDERR-2024-006941 WASATCH ENVIRONMENTAL, INC. ENVIRONMENTAL SCIENCE AND ENGINEERING 2410 WEST CALIFORNIA AVENUE SALT LAKE CITY, UTAH 84104 PHONE (801) 972-8400 FAX (801) 972-8459 e-mail: wei@wasatch-environmental.com www.wasatch-environmental.com CORRECTIVE ACTION PLAN ADDENDUM FORMER C-4 TOP STOP 15 SOUTH MAIN STREET GUNNISON, UTAH UST FACILITY NO. 2000220 RELEASE SITE EMHB Project No. 1241-026A Prepared for: Mr. Craig Larson Wind River Petroleum 5097 South 900 East Salt Lake City, Utah 84117 and Ms. Liberty Coe Utah Department of Environmental Quality Division of Environmental Response and Remediation 195 North 1950 West P.O. Box 144840 Salt Lake City, Utah 84114-4840 Prepared by: Wasatch Environmental, Inc. 2410 West California Avenue Salt Lake City, Utah 84104 ___________________________________________ Michael S. Cronin, P.G. Senior Project Manager and Senior Project Geologist Utah UST Certified Consultant CC 232 Utah P.G. 5546361-2250 May 8, 2024 Corrective Action Plan Addendum Former C-4 Top Stop, Gunnison Wasatch Environmental, Inc. Page i TABLE OF CONTENTS Section Page No. 1.0 INTRODUCTION .............................................................................................................................. 1 2.0 BACKGROUND ............................................................................................................................... 1 3.0 OBJECTIVE ..................................................................................................................................... 2 4.0 CORRECTIVE ACTION SELECTION ............................................................................................. 2 5.0 CORRECTIVE ACTION METHODS ................................................................................................ 2 5.1 Access Agreements ............................................................................................................ 2 5.2 Utility Clearance .................................................................................................................. 2 5.3 Traffic Control and Right-of-Way Encroachment ................................................................ 2 5.4 Underground Injection Control (UIC) Permit ....................................................................... 2 5.5 Notifications ......................................................................................................................... 3 5.6 Soil Borings and Injections .................................................................................................. 3 5.7 Site Protection and Restoration .......................................................................................... 3 6.0 REPORTING .................................................................................................................................... 3 7.0 PROPOSED SCHEDULE ................................................................................................................ 3 8.0 GROUNDWATER MONITORING .................................................................................................... 4 9.0 HEALTH AND SAFETY ................................................................................................................... 4 FIGURE Figure 1 – Injection Plan Map APPENDIX Appendix A – Regenesis Proposal Corrective Action Plan Addendum Former C-4 Top Stop, Gunnison Wasatch Environmental, Inc. Page 1 1.0 INTRODUCTION This Corrective Action Plan (CAP) Addendum presents information pertaining to additional corrective action measures to be implemented in response to the release from the former C-4 Top Stop facility (Facility) in Gunnison, Utah. This document specifically pertains to addressing residual dissolved phase petroleum hydrocarbon contamination remaining in the vicinity of 100 South and Main Street in Gunnison (see Figure 1). This document is an addendum to the CAP, dated September 30, 2008, and the Final CAP Addendum, dated May 31, 2013. This CAP Addendum is intended as a response to the following letters issued by the Utah Department of Environmental Quality (DEQ) Division of Environmental Response and Remediation (DERR): • “Corrective Action Plan and Additional Sampling Requirements”, dated October 22, 2021 (ERRL- 0382-21); • “Non-Compliance Letter”, dated November 18, 2022 (ERRA-29-22); and • “Notice of Violation and Order to Comply”, dated March 6, 2024 (ERRA-02-24). 2.0 BACKGROUND The Facility was located at the southeast corner of the intersection of Main Street and Center Street in Gunnison, Utah. On August 8, 2007, gasoline vapors were reported in businesses near the Facility. The release had impacted both the east and west sides of Main Street and a portion of the residential area between Main Street and 100 West Street, and between Center Street and 300 South Street (impacted area). Between August 2007 and September 2008, Wasatch Environmental, Inc., (Wasatch) conducted intensive subsurface investigation of the Facility and the impacted area. Another phase of intensive subsurface investigation work was conducted by Wasatch from 2011 to 2012. Groundwater monitoring has been conducted throughout the impacted area since the discovery of the release. Abatement and vapor mitigation measures were implemented upon discovery of the release in 2007 and were revised as our understanding of the impacts developed with the collection and evaluation of subsurface investigation data. Various remediation systems were installed throughout the impacted area including: five soil vapor extraction systems, a sparge curtain, and ten building sub-slab ventilation systems (see Figure 1). Injections of nitrate amendments and oxygen releasing compound, as well as multiple total fluid recovers events using a vacuum truck were also conducted in the impacted area specifically targeting groundwater impacts in the vicinity of groundwater monitoring wells MW-27 and MW-41. However, despite these corrective action and mitigation measures, even as most of the impacted area was successfully remediated and the remediation systems were decommissioned over time, residual impacts to groundwater (specifically total petroleum hydrocarbons as gasoline-range organics [TPH-GRO], benzene, and ethylbenzene exceeding the Utah Initial Screening Levels [ISLs]) persisted in the vicinity of groundwater monitoring wells MW-27 and MW-41. Because of the persistent impacts to groundwater in the vicinity of groundwater monitoring wells MW-27 and MW-41, the exposure risks associated with those impacts, and a desire to achieve regulatory closure of the release; the Utah DERR issued a letter (ERRL-0382-21) dated October 22, 2021, requesting that additional sampling be performed and that a CAP be submitted to address the remaining impacts. The additional sampling was performed by Wasatch in February 2022 and reported to the DERR in March 2022. No analytes were detected in the additional sample locations (MW-5 MW-26, and MW-43). However, failure to submit the requested CAP resulted in the issuance of a Non-Compliance letter (ERRA-29-22) dated November 18, 2022, and the Notice of Violation and Order to Comply letter (ERRA- 02-24) dated March 6, 2024 (both letters issued by the DERR to Wind River Petroleum). This CAP Addendum document is intended to satisfy the request for a CAP. Corrective Action Plan Addendum Former C-4 Top Stop, Gunnison Wasatch Environmental, Inc. Page 2 3.0 OBJECTIVE The objective of the work described in this CAP Addendum is to reduce analyte concentrations in groundwater occurring in the vicinity of monitoring wells MW-27 and MW-41 to concentrations below the Utah ISLs, so as to be protective of human health and the environment, and to facilitate regulatory closure of the release. 4.0 CORRECTIVE ACTION SELECTION Given the nature of the contaminants, technologies used thus far (with only limited success in the vicinity of monitoring wells MW-27 and MW-41), and the desire to expedite regulatory closure of the release; Wasatch has determined that the best corrective action measure would be the injection of substrate that would both trap contaminants as well as promote degradation of the contaminants (trap and treat). Therefore, Wasatch is proposing the injection of PetroFix™, by Regenesis Bioremediation Products (Regenesis), in the vicinity of monitoring wells MW-27 and MW-41. 5.0 CORRECTIVE ACTION METHODS Wasatch worked in conjunction with Regenesis to develop the injection plan and injectate loading. Wasatch provided data to Regenesis so that an injection plan could be developed and targeted at the specific contaminants present, the concentrations of those contaminants, the distribution of those contaminants in the subsurface, and the subsurface geology. As shown on Figure 1, and described in additional detail in Section 5.6, the injection plan involves the injection of a total of 2,800 pounds of PetroFix™ and 160 pounds of PetroFix EA Blend™ (electron acceptor blend), using 48 direct-push injection borings to be advanced in the vicinity of monitoring wells MW-27 and MW-41, and injecting at depths ranging from 13 to 20 feet below ground surface (bgs). The injection proposal from Regenesis is attached as Appendix A. 5.1 Access Agreements Wasatch would obtain signed access agreements with Gunnison City and affected private property owners prior to the commencement of corrective action activities. 5.2 Utility Clearance Wasatch would submit a utility clearance request to Blue Stakes at least two full business days prior to the commencement of the remediation work. The Blue Stakes request number would be communicated to Direct Push Services (DPS), the drilling subcontractor, so that they can duplicate the request. Wasatch would also have DPS perform a private utility locate prior to the commencement of the drilling work. 5.3 Traffic Control and Right-of-Way Encroachment Wasatch would have a traffic control plan prepared, and appropriate traffic controls deployed, prior to commencement of corrective action activities. Wasatch would obtain a right-of-way encroachment permit for work performed in the public right-of-way. 5.4 Underground Injection Control (UIC) Permit Wasatch would submit an application for an Underground Injection Control (UIC) permit to the Division of Water Quality (DWQ) for Class 5B6 beneficial use injection well(s) [subsurface environmental remediation injection well(s)] prior to the commencement of fieldwork. Injections would not be performed until the UIC permit has been approved. Wasatch would notify the DWQ when the work has been completed and the permit can be discontinued. Corrective Action Plan Addendum Former C-4 Top Stop, Gunnison Wasatch Environmental, Inc. Page 3 5.5 Notifications Wasatch would notify the Utah DERR, Gunnison City, affected private property owners, and Sanpete County Health Department, at least 72 hours prior to commencement of fieldwork related to the corrective action activities at the Site. 5.6 Soil Borings and Injections Sixteen injection borings would be clustered around monitoring well MW-27. Injections around monitoring well MW-27 would cover an area measuring approximately 21 feet x 21 feet, with the borings placed on a square grid, with the grid centered on monitoring well MW-27, and injection borings spaced 7 feet apart (see Figure 1). A total of 800 pounds of PetroFix™ and 40 pounds of PetroFix EA Blend™ would be injected at depths of 13 to 18 feet bgs in this area. A total of approximately 90 gallons of injectate (PetroFix™ and PetroFix EA Blend™ mixed with potable water as directed by Regenesis) would be injected into each boring. Sixteen injection borings would be clustered around monitoring well MW-41. Injections around monitoring well MW-41 would cover an area measuring approximately 21 feet x 21 feet, with the borings placed on a square grid, with the grid centered on monitoring well MW-41, and injection borings spaced 7 feet apart (see Figure 1). A total of 1,200 pounds of PetroFix™ and 80 pounds of PetroFix EA Blend™ would be injected at depths of 14 to 20 feet bgs in this area. A total of approximately 90 gallons of injectate would be injected into each boring. Sixteen injection borings would be arranged along the south side of 100 South Street to form a permeable reactive barrier between monitoring wells MW-27 and MW-41. The injection borings would be arranged in two east-west oriented rows, borings spaced 10 feet apart (rows approximately 70 feet long east to west, and 10 feet apart north to south), arranged in a staggered grid (see Figure 1). A total of 800 pounds of PetroFix™ and 40 pounds of PetroFix EA Blend™ would be injected at depths of 14 to 20 feet bgs in this area. A total of approximately 90 gallons of injectate would be injected into each boring. Injection boring locations may need to be adjusted in the field due to such factors as the location of various utilities. The actual boring locations will be measured in the field and documented. 5.7 Site Protection and Restoration Wasatch and our subcontractors would take reasonable precautions to protect the work site from damage and restore the work site to its original condition at the completion of the fieldwork. The work site would be left clean. The borings will be backfilled and in paved locations will be patched at the surface to match to the existing pavement. Superficial damage to grass lawns will be graded and re-seeded. 6.0 REPORTING Following implementation of the corrective action, Wasatch would author a report documenting the corrective action. The report would include narrative text describing the methods used and results obtained, a map showing the boing locations as they were actually placed, a photographic log, copies of permits, and other supporting documentation, as appropriate. Groundwater monitoring results documenting the anticipated reduction in analyte concentrations in groundwater over time would be reported in the semi-annual monitoring reports. 7.0 PROPOSED SCHEDULE Wasatch anticipates that field work will commence within 60 days of receiving notice to proceed from Wind River Petroleum. Wasatch, on behalf of Wind River Petroleum, would make every reasonable effort to obtain written access agreements from Gunnison City and affected property owners. However, neither Corrective Action Plan Addendum Former C-4 Top Stop, Gunnison Wasatch Environmental, Inc. Page 4 Wasatch nor Wind River Petroleum will be responsible for delays resulting from the refusal of Gunnison City or any property owner refusing to grant access for execution of the work. 8.0 GROUNDWATER MONITORING Groundwater monitoring would continue on the existing schedule, and monitoring the same locations (MW- 27 and MW-41), until the cleanup levels have been met for the period of one year (two consecutive semi- annual monitoring events). After cleanup levels have been met for a period of one year, Wasatch, would request regulatory closure of the release on behalf of and Wind River Petroleum. 9.0 HEALTH AND SAFETY Wasatch will author a site-specific health and safety plan (HASP) prior to the commencement of field work. A copy of the HASP will be on-Site at all times during field activities. Daily health and safety tailgate meetings will be conducted each morning during field activities. FIGURE April 26, 2024 Injection Plan Map 0.017 mg/L MW-5 MW-26 0.036 mg/L MW-27 Injection Area PRB Injection Area MW-41 Injection Area MW-27 Injection Area 16 borings Inject 13 - 18 feet bgs 800 lb PetroFix 40 lb PetroFix EA 90 gallons per point PRB Injection Area 16 borings Inject 14 - 20 feet bgs 800 lb PetroFix 40 lb PetroFix EA 90 gallons per point MW-41 Injection Area 16 borings Inject 14 - 20 feet bgs 1,200 lb PetroFix 80 lb PetroFix EA 90 gallons per point 39 West 100 South 29 West 100 South 100 South Street Injection Plan Inset Map APPENDIX A Regenesis Proposal