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Home My WebLink AboutDERR-2025-000867Rockwell Solutions, Inc., 718 E. Bridger Lane, Elk Ridge, UT 84651, 801-361-2930, rockwellutah@yahoo.com Rockwell Solutions, Inc. 718 Bridger Lane Elk Ridge, UT 84651 (801) 361-2930 December 26, 2024 Jay Cahoon Holiday Oil 3115 West 2100 South Salt Lake City, UT 84119 Re: Corrective Action Plan Former Holiday Oil #51 Facility ID: 4001393 153 W 9000 South Release ID: NZU Sandy, Utah Dear Mr. Cahoon: Rockwell Solutions submits this corrective action plan (CAP) to install an injection trench, excavate soil, and dewater contaminated groundwater at the above-referenced site. INTRODUCTION The Former Holiday Oil #51 was a retail fueling facility that operated from April 2010 to November 2020 when the tanks were removed and the buildings demolished. The gas station was condemned in 2020 to accommodate roadway expansion. Prior to April 2010 the facility was owned and operated by Sinclair. The property, located on the southwest corner of the 9000 South Street and Monroe Street intersection in Sandy, Utah, is currently vacant. Releases were reported at the site in 2011 (MWB) and two in 2013 (MPP and NAI). MWB and NAI were closed in 2012 and 2013, respectively. In February 2021, DERR determined that Holiday Oil was the responsible party (RP) for contamination at the site and closed release MPP. Release NZU was opened with Holiday Oil as the RP on February 11, 2021. A subsurface investigation in October 2020 identified soil and groundwater contamination near the western boundary of the gas station. The UST system was removed and all buildings were demolished in November 2020. Subsurface investigations and groundwater monitoring have defined the extent of soil and groundwater contamination. The area of maximum contamination is on the west side of the site with a groundwater contaminant plume extending to the west. The objective of the corrective action is to excavate soil from a trench on the west side of the site, remove contaminated soil, remove and treat impacted groundwater, and inject the treated water containing a hydrogen peroxide solution back into the trench. Corrective Action Plan, Former Holiday Oil #51 (4001393), Sandy, Utah Rockwell Solutions, Inc., 718 E. Bridger Lane, Elk Ridge, UT 84651, 801-361-2930, rockwellutah@yahoo.com 2 SCOPE OF SERVICES Public Notification Neighboring properties will be notified of the work and given the opportunity to comment. A copy of the public notice is attached. Monitoring Well Replacement Monitoring well MW-1R cannot be located and has been apparently destroyed. The monitoring well will be replaced. Groundwater Sampling Prior to remediation activities, groundwater samples will be collected from MW-1R, MW- 2R, MW-4, MW-5, MW-6R, MW-7, and MW-9R. Excavation, Dewatering, and Reinjection A trench approximately five feet wide, 64 feet long, and ten feet deep will be installed near the west property boundary. If the trench were to continue farther south it would intercept the former tank basin excavation and injected groundwater would fill the former excavation rather than stay in the targeted trench area. Throughout the excavation soil will be checked using a photoionization detector (PID). All soil from the excavation will be hauled to ET Technologies soil disposal facility in Salt Lake City. The total volume of soil to be removed and hauled to ET Technologies is approximately 178 tons. The estimated excavation trench area is shown on Figure 1. Soil confirmation samples will be collected at the depth of the approximate water table on the excavation walls and at the bottom of the excavation. Samples will be submitted to a Utah- certified laboratory for analysis of MTBE, benzene, toluene, ethylbenzene, xylenes, and naphthalene (MBTEXN) and total petroleum hydrocarbons-gasoline range organics (TPH-GRO) using EPA Method 8260b, and TPH-diesel range organics (TPH-DRO) using EPA method 8015b. Backfill The trench will be filled with gravel to approximately two feet bg and will be completed with road base. A sump or well will be left in place through which water can be pumped out or injected. Dewatering Groundwater in the excavation will be pumped out into an onsite frac tank. After excavation and dewatering are completed, groundwater will be allowed to fill the trench and will then be sampled. The groundwater sample will be collected and analyzed for MBTEXN and TPH- GRO using EPA Method 8260b, and TPH-DRO using EPA method 8015b. Treatment and Reinjection The water in the frac tank will be treated by air sparging using a large compressor or by passing it through an activated carbon filter. After laboratory analysis confirms that the frac tank water is less than Initial Screening Levels, concentrated hydrogen peroxide will be mixed in to the water to form an approximate 5% hydrogen peroxide solution , which will be discharged back into the trench. Corrective Action Plan, Former Holiday Oil #51 (4001393), Sandy, Utah Rockwell Solutions, Inc., 718 E. Bridger Lane, Elk Ridge, UT 84651, 801-361-2930, rockwellutah@yahoo.com 3 The hydrogen peroxide solution will also be injected into monitoring wells MW-1R, MW-2R, MW-5, MW-6R, and MW-7R. Reports A final corrective action report will be prepared documenting groundwater monitoring, excavation, and injection activities and will include analytical results. Post Corrective Action Groundwater Monitoring Approximately three months after corrective action, groundwater samples will be collected from MW-1R, MW-2R, MW-4, MW-5, MW-6R, MW-7, and MW-9R. A groundwater monitoring report will be prepared. METHODOLOGY DETERMINATION The trench area will target the highest known areas of residual soil contamination and is much less expensive than a large-scale excavation. The injection trench will allow treatment of the impacted groundwater without installing an insitu treatment system that would require equipment, electricity, and monthly operation and maintenance. SCHEDULE Trenching, dewatering, treatment, and injection activities will last last approximately two weeks. Please feel free to contact me should you have any questions or concerns at 801-361-2930. Sincerely, David S. Hansen Certified UST Consultant CC0130 Rockwell Solutions, Inc. cc: Hillary Mason, DERR Figure 1 NORTH Approx. scale in feet 00 80 Former Holiday Oil #51 153 W 9000 South Sandy, Utah MW-28MW-29(2631.66)(2632.03)(2626.92)MW-9 r d Tr nPoposeech MW-1R MW-8 MW-2R MW-11 MW-22 (51.94)MW-15R (55.33) MW-13 MW-12 MW-6R MW-9R (85.35) = Benzene Concentration (mg/L) = Benzene Isoconcentration (mg/L) 9000 South Monroe Street MW-5 MW-10 MW-7 MW-3 (Destroyed) MW-4 00 Monitoring Well Location Trench Public Notice PUBLIC COMMENT PERIOD ENDS JANUARY 24, 2025 Leaking Storage Tank Petroleum Cleanup Project Former Holiday Oil #51, 153 W 9000 South, Sandy, Utah The Division of Environmental Response and Remediation (DERR) is planning to oversee the remediation of petroleum-contaminated soil at the above site. The environmental consultant for this project is Rockwell Solutions, Inc. The former Holiday Oil #51 was located at 153 W 9000 South in Sandy, Utah. The property is now vacant. A release was discovered/reported at the site in February 2021. Soil and groundwater contamination remain at the site. The proposed remediation method is excavation, groundwater removal and treatment, and reinjection. The following tasks will take place: 1) Excavate a trench approximately five feet wide, sixty-four feet long, and ten feet deep. Figure 1 shows the proposed location of the trench 2) Haul off and dispose of the impacted soil 3) Dewater the excavation, storing the impacted groundwater in a 18,000-gallon frac tank 4) Treat the groundwater in the frac tank with air sparging to remove hydrocarbons 5) Place gravel in the trench 6) When laboratory data indicates the treated water is clean, hydrogen peroxide will be mixed into the water and the water will be injected into the trench Remediation activities are planned to begin in the winter or early spring of 2025 and will take approximately one week to complete. A copy of the Corrective Action Plan prepared for this site is available at the DERR in Salt Lake City (address below; office hours 8:00 a.m. to 5:00 p.m., Monday through Friday). For additional information or to provide comment(s), please contact one of the following: Hillary Mason (801) 536-4100 hmason@utah.gov Division of Environmental Response and Remediation 195 North 1950 West, 1st Floor P.O. Box 144840 Salt Lake City, Utah 84114-4840 David Hansen (801) 361-2930 rockwellutah@yahoo.com Rockwell Solutions, Inc 718 E Bridger Lane Elk Ridge, Utah 84651