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Home My WebLink AboutDERR-2025-002680 EMERGENCY CLEANUP ABATEMENT ACTION PLAN Hyrum Short Stop 325 W. Main Street Hyrum, Cache County, Utah Facility Identification No. 0100519 Release Site ONA Prepared for: Offen Petroleum 5100 E. 78th Avenue Commerce City, Colorado 80022 and Ramdas Ji Hyrum LLC 325 W. Main Street Hyrum, Utah 84319 Prepared by: Broadbent & Associates, Inc. 8787 S. Redwood Road, Suite 200 West Jordan, Utah 84088 (801) 505-9251 www.broadbentinc.com April 7, 2025 Project No. 25-14-108 April 7, 2025 Project No. 25-14-108 Utah Department of Environmental Quality Division of Environmental Response & Remediation and Division of Water Quality 195 North 1950 West Salt Lake City, Utah 84114-4840 Attn.: Ms. Eileen Brennan & Mr. Brendon Quirk Re: Emergency Cleanup Abatement Action Plan Hyrum Short Stop, 325 N. Main Street, Hyrum, Cache County, Utah Facility Identification Number: 0100519, Release Site ONA Dear Ms. Brennan & Mr. Quirk: Broadbent & Associates, Inc. is pleased to submit this Emergency Cleanup Abatement Action Plan associated with the petroleum hydrocarbon release discovered on March 14, 2025 at the Hyrum Short Stop located at 325 W. Main Street in Hyrum, Cache County, Utah. This document presents the generalized plan to conduct necessary emergency abatement actions to address residual petroleum hydrocarbon at the source area and downstream pathways associated with the March 14, 2025 discovered release. Please do not hesitate to contact us at (801) 505-9251 if you should have questions or require additional information regarding this submittal. Sincerely, BROADBENT & ASSOCIATES, INC. Aric C. Morton, PG Principal Geologist Certified UST Consultant CC 0276 (expires 12/31/25) Certified Groundwater & Soil Sampler GS-1869 (expires 9/14/25) cc: Mr. Ken Moser, Offen Petroleum Mr. Harpreet Happy Singh & Raghunandan Singh, Hyrum Short Stop Mr. Mark Landress, Mr. Jeff King & Mr. Lloyd Jones, Verdantas Mr. Scott Kahler & Mr. Jon Stokes, EnviroServe Mr. Brendon Quirk, Utah DWQ Mr. Kade Maughan, Hyrum City EMERGENCY CLEANUP ABATEMENT ACTION PLAN Hyrum Shortstop 325 W. Main Street Hyrum, Cache County, Utah Release Site ONA TABLE OF CONTENTS No. Section Page 1.0 INTRODUCTION .......................................................................................................... 1 2.0 GENERALIZED MARCH 14, 2025 RELEASE DISCOVERY DETAILS ................................... 1 3.0 ER CLEANUP ABATEMENT ACTIONS ........................................................................... 2 3.1 AST Removal ....................................................................................................... 2 3.2 Initial Abatement Liquid Recovery, Storage, and Disposal ................................. 3 3.3 Emergency Excavation Abatement ..................................................................... 4 3.3.1 Primary Source Area Excavation .......................................................... 4 3.3.1.1 Tank AST-4 Foundation Safety Measures ................................ 5 3.3.2 Delineation Sampling ........................................................................... 5 3.3.3 Downstream Excavation ...................................................................... 6 3.3.4 Tank Excavation Ditch Dewatering ...................................................... 6 3.3.5 Downstream Confirmation Sampling ................................................... 6 3.3.6 Laboratory Analysis .............................................................................. 6 3.3.7 Loading and Transport of Impacted Soils ............................................. 6 3.4 Surface Restoration ............................................................................................ 7 4.0 GENERAL HEALTH & SAFETY CONCERNS ..................................................................... 7 5.0 ABATEMENT SCHEDULE ............................................................................................. 7 6.0 ABATEMENT ACTION COMPLETION REPORT .............................................................. 7 7.0 LIMITATIONS .............................................................................................................. 7 8.0 REFERENCES ............................................................................................................... 8 List of Figures Figure 1 Site Map Figure 2 Site Detail Map Figure 3 Salt Hollow Park Map Figure 4 Tank Battery Map EMERGENCY CLEANUP ABATEMENT ACTION PLAN Hyrum Short Stop 325 W. Main Street Hyrum, Cache County, Utah Site Release ONA 1.0 INTRODUCTION Broadbent & Associates, Inc. (Broadbent) has prepared this Emergency Cleanup Abatement Action Plan (ER Plan) associated with the petroleum hydrocarbons release discovered on March 14, 2025 at the Hyrum Short Stop located at 325 W. Main Street in Hyrum, Cache County, Utah (Site). Abatement actions completed under this release have been identified as Release Site ONA. The objective of this ER Plan is to implement emergency abatement actions to address petroleum hydrocarbon source area impacts within the Site’s aboveground storage tank (AST) battery and address residual downstream impacts within Hyrum City’s stormwater system network. The location of the Site in Hyrum is depicted in Figure 1. Figure 1 also depicts the general flow path of the release from the Site’s AST battery, off-Site through ditches in the adjacent field to the north, through Salt Hollow Park, and into Hyrum City’s stormwater system before its eventual discharge at the Hyrum City Stormwater Outfall northwest of the city. This ER Plan has been prepared for the Utah Department of Environmental Quality, Division of Environmental Response & Remediation (DERR) as requested in their March 27, 2025 email. This ER Plan provides a general description of the following tasks to implement emergency abatement actions at the Site and to address downstream impacts: 1.) Provide an anticipated timeline associated with removal of tanks AST-1, AST-2, and AST-3. 2.) A description of handling and disposal plans for surface water and product collected during initial and future abatement efforts. 3.) A detailed description of the planned source area excavation abatement actions after AST removal. 4.) A detailed description of the sampling plan consistent with abatement actions within the AST battery. 5.) A discussion of safety and precautions associated with AST-4, the new tank on the concrete base, and any remaining product lines. 6.) Additional details associated with implementation of abatement actions and plans. 2.0 GENERALIZED MARCH 14, 2025 RELEASE DISCOVERY DETAILS A release of petroleum hydrocarbons was discovered on March 14, 2025 which was traced to the AST battery at the Hyrum Short Stop property. Unused tank AST-1 was identified as the source of the petroleum hydrocarbon release as the tank’s manway was not properly secured. Accordingly, gasoline was released from AST-1 onto surrounding soil and infiltrated into the subsurface as no liner or secondary containment is present. Groundwater levels in the AST battery are between three (3) and four (4) feet below ground surface (bgs). Infiltrating gasoline migrated north through the subsurface towards a ditch that is located immediately adjacent to the tank battery and the Site. Figure 2 depicts the Site and the ditches in the field to the north. Groundwater surfaces in the “East-West Ditch” and flows west where it then turns into the “Northeast Ditch” and continues across an undeveloped field (the Field). The Northeast Ditch surface water flows across the Field where it passes through a conduit located under N 100 W and enters the southeast corner of Salt Hollow Park. Stormwater continues to move generally north passing through the Salt Hollow Park Pond until it intersects Hyrum City’s stormwater infrastructure at W 200 N. Figure 3 depicts the general flow path through Salt Hollow Park. Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 2 The stormwater pathway from N 200 W is generally to the west and northwest passing through the Hyrum City’s Pump Station until the discharge outfall at the intersection of W 400 N and S 1900 W. Odors and sheen were witnessed downstream of the outfall by residents on March 14, 2025 who reported their observations to Hyrum City personnel. Initial response actions generally included the following: • Placement of booms and pads along the immediate flow path of the area of impact; • Construction of containment to prevent further downstream migration of product and impacted surface water especially in the ditches north of the AST battery; • Use of a vactor to address residual sheen and product located within Hyrum City’s stormwater system; • Storage of recovered water and product for profiling and ultimate disposal; • Continued inspection of the release flow path to maintain containment and collection points; • Pressure washing select areas and jetting of subsurface stormwater infrastructure to address sheen and odors; • Construction of a sump and interceptor trench to capture migrating gasoline from the AST battery; and • Continued use of the vactor to recover product and water impacts in the interceptor trench and ditch north of the AST battery. Regular inspection and maintenance activities include approximate daily changeout of booms and pads to prevent saturation and facilitate continued containment and recovery operations. Underflow dams are inspected daily as well. Required maintenance to ensure continued operation of the underflow dams is conducted as required. The volume of petroleum hydrocarbons released from AST-1 is estimated at approximately 1,300 gallons. This release volume is based on the March 18, 2025 update to the Environmental Incident Report Number 19553 which indicated that 4,000 gallons of gasoline were delivered with 2,700 gallons of gasoline recovered from AST-1. Historical releases of petroleum hydrocarbons have been documented at the Site and were under investigation by the former property owner Jeff Manning prior to discovery of the March 14, 2025 incident. 3.0 ER CLEANUP ABATEMENT ACTIONS Activities associated with implementation of emergency abatement cleanup action are provided below with general details of selected tasks. These tasks are generally consistent with requirements included in DERR’s March 27, 2025 email briefly summarized above in Section 1.0. 3.1 AST Removal A Closure Plan for removal of three (3) of the four (4) ASTs associated with the Site was prepared and submitted by Commercial Services Unlimited, Inc. (CSU) on March 28, 2025. The Closure Plan included details of the four (4) ASTs located at the Site which included the following: Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 3 Tank ID Tank Type Capacity (gallons) Contents Operational Status Change in Service AST-1 Steel 12,000 RUL Not in Use Removal AST-2 Steel 8,000 SUL In Use Removal AST-3 Steel 8,000 Diesel In Use Removal AST-4 Double Wall Steel 10,000 RUL In Use No Change AST-1 is the release point of petroleum hydrocarbons associated with discovered March 14, 2025 release. The contents in tanks AST-2 and AST-3 were removed on April 4, 2025 to initiate closure activities. Removal of these tanks will facilitate access to residual hydrocarbon impacts associated with commingled releases. Bruce Barton of CSU will provide oversight of tank removal actions as the Utah Certified Tank Remover TR#0426. The removed tanks will be red-tagged and left on-Site at the Hyrum Short Stop until a decision is made to pursue re-certification or transported off-Site for disposal via recycling. DERR has waived closure assessment sampling associated with removal of AST-1, AST-2, and AST-3 as these tanks are situated over known areas of historical impacts. Physical removal of tanks AST-1, AST-2, and AST-3 are scheduled to begin on April 8, 2025. CSU indicated that product conveyance piping associated with the tanks has been removed between the tanks to the STPs. Conveyance piping from the STPs to the dispensers appears to still be in-place. The Site will not be able to provide regular unleaded gasoline sales during tank removal activities. Additional conveyance piping will be removed as necessary to facilitate access to impacted media for excavation. CSU will be contacted to assist with removal of conveyance piping as required during excavation abatement actions associated with the tank battery. 3.2 Initial Abatement Liquid Recovery, Storage and Disposal Initial abatement actions to address surface water impacts included utilization of a vactor truck to recover visible product and sheen within the ditches and waterways downstream of the tank battery. As of the date of this ER Plan, approximately 200,000 gallons of surface water and product have been recovered as of April 3, 2025. It is estimated that approximately 600-650 gallons of product have been recovered as of March 31, 2025 when an interface probe was used to measure apparent thickness. The volume of recovered liquids has increased since March 31, 2025 as an interceptor trench was installed to collect product from the AST battery. Downstream sheen observations have only been recorded after precipitation events. Sheen is still present on the water in the East-West Ditch. In addition, containment dams are still in-place to prevent product migration and assist with recovery. Booms and pads are still being used to assist downstream mitigation efforts. Recovered liquids are stored the 10 frac tanks that have been mobilized to the parking lot of Salt Hollow Park and on the actual Site property. The liquids in the frac tanks have been initially profiled for off-Site disposal; however, logistics associated with on-Site treatment and discharge are being evaluated due to the volume (current and future) of recovered liquids. It is expected that liquids generated during future abatement or dewatering efforts will be temporarily stored in frac tanks prior to off-Site disposal or on-Site treatment prior to permitted discharge. A treated groundwater permit (UTG790000) will be required if discharge is to occur to surface water or into Hyrum City’s stormwater system. Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 4 3.3 Emergency Excavation Abatement Details associated with excavation abatement actions within the primary source area/tank battery and downstream areas of impact are described below. Broadbent will provide oversight of abatement actions by a Utah Certified PST Consultant (CC 276) as well as providing Utah Certified UST Groundwater and Soil Samplers (GS 1836 & GS 1869). It is anticipated that preliminary sampling will be conducted to assist with initial delineation efforts prior to excavation. 3.3.1 Primary Source Area Excavation Excavation of the primary source area will consist of the removal of impacted soil around the former tank footprints of AST-1, AST-2, and AST-3. The area of excavation is initially expected to be approximately 2,100 ft2 (35 x 60ft). Field observations of visual impacts indicate that excavation depth will extend to at least five (5) feet bgs at a minimum. The initial estimate of impacted soil volume to be removed is not expected to exceed 500 cubic yards. The excavation is expected to extend below the groundwater interface to address residual impacts within the seasonal smear zone. The southern boundary of the source area excavation is expected to extend up to seven to eight (7-8) feet from the north side of the new concrete pad for tank AST-4. This distance is being proposed to prevent compromising the structural integrity of AST-4’s concrete foundation. The northern boundary is expected to be at the East-West Ditch while the east and west boundaries will be near the existing containment berm. Excavation boundaries may be extended based on visual observations and laboratory analytical results along with prior approval by DERR. Depth to water in the excavation is expected to be between three and four (3-4) feet bgs based on measurements in adjacent monitoring wells. With that stated, impacted groundwater will be encountered which may require dewatering and/or skimming of visual product off the water surface in the excavation. Recovered liquids will continue to be stored in frac tanks prior to treatment and discharge or off-Site transportation for disposal. A treated groundwater permit (UTG790000) will be required if discharge is to occur to surface water or into Hyrum City’s stormwater system. It is proposed that up to 10 confirmation soil samples be collected by a certified Utah sampler from the excavation sidewalls after field observations indicate removal of residual impacts has potentially occurred or excavation limits have been achieved. Additional excavation confirmation sampling will include four (4) bottom soil samples and two (2) water samples. One duplicate soil sample will be collected at the tank battery location. Laboratory analytical results will be compared to DERR’s Initial Screening Levels (ISLs) to assist with evaluation of abatement actions and recommendations. Remedial piping may be placed within the excavation to facilitate extraction or application of injectants to assist with chemical oxidation or biodegradation of residual mass. The excavation will be backfilled and compacted after installation of remedial piping. During the excavation, engineering controls will be implemented that prevent stormwater and groundwater run-on/run-off from impacting downstream ditches. The controls will meet engineering Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 5 best management practices and may include sandbags, plastic sheeting, temporary berms, and transfer of liquids to the frac tanks at Salt Hollow Park for storage prior to treatment/discharge or disposal. 3.3.1.1 Tank AST-4 Foundation Safety Measures & Existing Monitoring Well Protection DERR specifically requested discussion associated with protection of tank AST-4 and the structural integrity of its concrete foundation. AST-4 will be the sole source of gasoline to facilitate operations at the Hyrum Short Stop and disruption of gasoline would impact store operations. To prevent impacts to AST-4, the southern boundary of the source area excavation is expected to extend up to seven to eight (7-8) feet from the north side of tank AST-4’s concrete pad. Should cracks or sloughing be observed in the direction of tank AST-4, a stop work will be implemented until appropriate shoring and/or backfilling occurs to prevent further destabilization of the southern sidewall. In addition, existing groundwater monitoring wells will be identified and protected during abatement activities. Existing groundwater monitoring wells associated with previous investigations of the tank battery have been identified in the field and have been visually marked to prevent damage. 3.3.2 Delineation Sampling Downstream impacts associated with this release included off-Site product migration along the ditches in the Field which continued as sheen through Salt Hollow Park, Hyrum City’s stormwater system (including a pump station), and continued out beyond the outfall northwest of town. Sheen has been observed periodically with subsequent precipitation events in the Salt Hollow Park Pond and further downstream at areas where the surface water and the bank interface are disturbed. Accordingly, residual impacts are expected to be present along the downstream pathway and delineation sampling is recommended to assist with evaluating excavation downstream of the source area. It is assumed that soil excavation will be required in the Field along the East-West Ditch due to the ditch’s proximity to the tank battery and the relatively consistent presence of product. It is proposed that delineation sampling occur in sediment, soil, and surface water at approximate intervals of 50 feet prior to implementation of excavation in the East-West Ditch. Sampling along the East-West Ditch is expected to occur at seven (7) locations as depicted in Figure 2. One (1) duplicate sample set will be collected in the East-West Ditch. Delineation sampling will be implemented at the beginning of the Northeast Ditch and continue at intervals of 100 feet downstream until the culvert is reached at the end of the ditch in the Field. Four (4) locations will be sampled along the Northeast Ditch. Figure 2 depicts proposal sampling locations along the East-West and Northeast Ditches. One (1) duplicate sample set will be collected in the Northeast Ditch. Sheen may be trapped within the rocks that border the Salt Hollow Park Pond. It is proposed that two (2) soil samples be collected on both sides of the pond behind the embankment rocks by utilizing a hand auger to access soil through the grass. Pressure washing the perimeter of the pond may be considered to assist with mobilizing residual sheen for collection. Three (3) water samples are proposed to be collected upstream of the pond, at the pond discharge, and in the waterway before the water enters Hyrum’s subsurface stormwater infrastructure. Figure 3 depicts proposed sampling locations in Salt Hollow Park. One (1) duplicate sample set will be collected in the Salt Hollow Park. Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 6 Additional sediment, soil and surface water samples will be collected downstream of the Hyrum stormwater outfall. Appropriate samples will be collected in the north and east contributory ditches prior to their intersection with discharge of the Hyrum stormwater outfall. A duplicate sample set will be collected at the Hyrum stormwater outfall. A surface water sample will be collected inside the Hyrum Pump Station. Additional off-Site sample locations are depicted in Figure 1. 3.3.3 Downstream Excavation Laboratory analytical results of downstream delineation sampling will be evaluated to determine if residual impacts in soil and sediment need to be removed via excavation. It is anticipated that most of the downstream excavation will occur in the East-West and Northeast Ditches in the Field. Excavation of potential residual impacts in Salt Hollow Park and at the Hyrum Stormwater Outfall are not known. Delineation through appropriate media sampling will assist with evaluating the extent of downstream abatement required. 3.3.4 Tank Excavation and Ditch Dewatering Dewatering within the tank excavation and downstream ditches may be implemented to facilitate removal of residual impacts, obvious product, and visible sheen. Dewatering water will most likely be removed within the tank excavation utilizing a vactor truck. Recovered water will be temporarily stored in frac tanks until disposal or on-Site treatment. 3.3.5 Downstream Confirmation Sampling Confirmation samples will be collected after excavation activities are completed in identified areas of concern. In general, the confirmation samples will be collected in the same area as the delineation samples with select exceptions to be authorized by DERR. 3.3.6 Laboratory Analysis Collected samples will be submitted under chain-of-custody documentation to Chemtech-Ford Laboratories (Chemtech) in Sandy, Utah for analysis of select volatile organic compounds (VOCs) including benzene, toluene, ethyl benzene, total xylenes, naphthalene (BTEXN), and methyl-tert-butyl ether (MTBE) by EPA Method 8260B, and for total petroleum hydrocarbons in diesel range (TPH-DRO) and total petroleum hydrocarbons in gasoline range (TPH-GRO) by EPA Method 8015. One (1) sidewall sample will be analyzed for Universal Soil Classification (USC) by ASTM Method D2488-90. TPH-DRO analysis will include a silica gel cleanup to assist with hydrocarbon detection. Two (2) soil samples and two (2) water samples with the highest concentrations of DRO and GRO will be analyzed for fractionation of the petroleum constituents to evaluate receptor risk associated with potential residual impacts. 3.3.7 Loading and Transport of Impacted Soils It is assumed that excavated soil will be temporarily stored on-Site to assist with profiling prior to off- Site disposal. Staged soil will be placed on visqueen and bermed to prevent impacts to underlying soil. Visqueen will also be used to cover stockpiles during inclement weather, overnight, or when no active work is occurring on the stockpiles. The most cost-effective disposal method will be selected. Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 7 3.4 Surface Restoration In general terms, every effort will be made to restore the Site’s surface conditions to a similar elevation and topography prior to implementation of emergency abatement actions. The tank battery excavation is expected to be backfilled and compacted to the general original grade. Imported material may consist of pea gravel or other base rock from approved sources. Off-Site excavation may require additional restoration efforts in Salt Hollow Park if abatement is required. Riprap or other materials may be considered to replace excavated soil along downstream ditches. 4.0 GENERAL HEALTH & SAFETY CONCERNS Safety for on-site personnel, the surrounding community and the environment is of paramount concern at this Site. As such, Site safety orientation meetings will be held at the onset of abatement operations to clarify potential issues/hazards that are anticipated during operations, and their mitigation measures. This meeting will be given by the Site Safety Officer, and personnel that are expected to perform work associated with this project will be present. For those personnel that are not present, a separate orientation meeting will be required. In addition, daily tailgate meetings will be held to reiterate the need for safe completion of work and to identify potential hazards that were encountered during the previous day’s events, and/or not anticipated as part of the pre-work safety orientation meeting. Abatement work will be primarily conducted in Modified Level D and/or upgraded to a Modified Level C personal protective equipment (PPE) when necessary. Modified Level D PPE will consist of a hard hat, American National Safety Institute approved safety glasses, steel-toed boots, Tyvek® (or a comparable material) chemical protective clothing, and hearing protection if determined necessary. Level C PPE will consist of Modified Level D requirements as well as half-face air purifying respirators (APRs) with particulate filters installed. Noise reduction will be a concern during abatement actions. Noise levels will be kept to a practical minimum during abatement operations to protect workers and limit disruption to the public. 5.0 ABATEMENT SCHEDULE The proposed abatement schedule has technically been implemented with submittal of the Closure Plan for the AST-1, AST-2, and AST-3. It is expected that the tank removals will be initiated on April 8, 2025. Broadbent will implement delineation and excavation as soon as possible after completion of the tank removals and receipt of DERR’s acceptance of this ER Plan. Excavation within the source area and along the downstream flow path is expected to require up to 15 days to complete. Activities associated with this ER Plan are generally expected to be complete by April 30, 2025. 6.0 ABATEMENT ACTION COMPLETION REPORT Broadbent will prepare an Emergency Cleanup Abatement Action Report for submittal to DERR within 60 days following completion of emergency abatement actions. The report will include, but will not be limited to, a description of activities completed for this project as well as the documentation of the Broadbent & Associates, Inc. Emergency Cleanup Abatement Action Plan West Jordan, Utah Hyrum Short Stop/Hyrum, Utah April 7, 2025 Page No. 8 lateral and vertical extent of the excavation boundaries. In addition, the quantities of material generated, and their final disposition will be incorporated into the report. Analytical data from collected media sampling (compared to ISLs) and waste disposal records will be provided in the summary report for review by DERR. 7.0 LIMITATIONS Discovery of hazardous conditions not reasonably anticipated or addressed in the scope of this associated ER Plan, which may impact Offen Petroleum, Hyrum Short Stop, or other Site personnel associated with field work, may constitute a changed condition mandating re-negotiation of the scope of work described herein or termination of services. Broadbent will do its best to alert Offen Petroleum and Hyrum Short Stop of matters which, in the opinion of Broadbent require immediate attention to protect public health, safety, and environment. Broadbent will make every effort to advise Offen Petroleum and Hyrum Short Stop of matters which should be reported to government regulatory agencies. However, Offen Petroleum and Hyrum Short Stop are solely responsible for reporting such matters, and Broadbent shall not be held liable in the event that the proper agency is not notified. Our services will be performed in accordance with generally accepted practice at the time work commences. Results and recommendations will be based on review of available documentation and written or verbal correspondence with appropriate regulatory agencies, laboratory results, observations of field personnel, and the points investigated. No warranty is expressed or implied. 8.0 REFERENCES CSU Limited, Inc. 2025. Hyrum Closure Plan Site 0100519 email from Rock Garner, March 28. Utah Division of Environmental Response and Remediation, 2025. Environmental Incident Report – Update: Hyrum Diesel Spill, Report Number 19553, March 18 update. Utah Division of Environmental Response and Remediation, 2025. ONA/Hyrum: Tank Closure Plan & emergency Abatement Plan email from Eileen Brennan, March 27. FIGURES Main Street N 4 0 0 W W 300 N Release Point Hyrum Pump Station Salt Hollow Park Field Hyrum Stormwater Outfall Site Map 325 Main Street Hyrum, Utah Project No. 25-14-108 Figure Prepared by: AGH Reviewed by: JEH Date: 4/4/25 1 0 SCALE: 1 inch = 1,250 feet 1,250 2,500 LEGEND Subject Property Boundary (Approximate) Flow Line Proposed Soil, Sediment, and Surface Water Sample Locations Proposed Surface Water Sample Locations Hyrum Short Stop Auto Canopy and Fuel Dispensers Main Street Nor t h e a s t D i t c h East-West Ditch ASTs Tank Battery W 100 N Release Point Field Site Detail Map 325 Main Street Hyrum, Utah Project No. 25-14-108 Figure Prepared by: AGH Reviewed by: JEH Date: 4/4/25 2 0 SCALE: 1 inch = 100 feet 100 200 LEGEND Subject Property Boundary (Approximate) Proposed Soil, Sediment, and Surface Water Sample Locations Salt Hollow Park Salt Hollow Pond W 100 N W 200 N Salt Hollow Park Map 350 W 100 N Hyrum, Utah Project No. 25-14-108 Figure Prepared by: AGH Reviewed by: JEH Date: 4/4/25 3 0 SCALE: 1 inch = 100 feet 100 200 LEGEND Stormwater Pathway (Approximate) Proposed Soil and Sediment Sample Locations Proposed Surface Water Sample Locations AST-2 AST-3 AST-1 AST-4 Tank Battery Map 325 Main Street Hyrum, Utah Project No. 25-14-108 Figure Prepared by: AGH Reviewed by: JEH Date: 4/4/25 4 0 SCALE: 1 inch = 15 feet 15 30 LEGEND Proposed Excavation Proposed Sample Locations Proposed Water Sample Locations