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HomeMy WebLinkAboutDERR-2025-000796Facility Information Facility Name:PYRAMID OIL CO.Release ID:OBL Facility Address:3120 S MAIN ST SOUTH SALT LAKE, UT 84115 Facility ID:4000124 Notification Date:07/01/2021 Owner Name:Darrel Grant Vincent Reporting Party:Neil Hickenlooper Owner Address:4996 South 950 East SOUTH OGDEN, UT 84403 Project Manager:Mark Crim Site Assessment Information a. Contaminant Source Information Cause of Release (if known) Product Released Amount Released (gal) Size (gal) # of USTs Tank Piping Disp Over/Spill Other Comments Gasoline UNK Diesel UNK 3K Yes Yes Yes UNK Waste Oil Unknown Other Tank Piping Disp Free Prod Cont Soil Sources Removed:No No Yes No No b. Land Use Information Current Land use at the Site:Commercial Surrounding Neighborhood:Commercial (Note: Surrounding land use is Residential if one or more residences share a common property line with the Facility) c. Soil Information Soil Type(s) Depth to Contaminated Soil (feet below land surface): 8-12 SC-Clayey sands 0-6' SM-Silty sands 6-14' Method of Soil Type Identification:Unified Soil Classification d. Groundwater Information Was groundwater encountered?:Yes Thickness of Free Product:NA Depth to groundwater (feet below land surface): 9 Is groundwater impacted at any concentration: Yes Groundwater flow direction:NW Measured Slope direction of surface topography:W e. Distance from Highest Measured Contaminated Concentrations and Sampling Location to Nearest Potential Receptor Receptors:(Enter distance to each receptor from corresponding sampling location in feet) Distance- Location Distance- Location Water Line:15 - MW-2 Sewer Line:>30 - GP-01 Building Desc:Commercial Electrical:90 - B-2 Natural Gas:10 - MW-7 Other Desc: Building:10 - MW-7 Telephone:25 - GP-01 Property Line 0 - MW-2 Storm Drain:10 - MW-2 Other(specify): - Receptors Within 500 feet: Municipal Well:190 WR#57-10223 Domestic Well:502 WR#57-43389 Irrigation Well:455 WR# 57-4620 Other: Surface Water(specify type: lake, stream, creek, river, wetland):Dist: >500 Desc: Mill Creek Utah's RBCA Tier 1 Worksheet Printed on: 11/18/2024 7:04:41 AM Facility History - Executive Summary In April 2021, a realty-styled subsurface investigation revealed soil and groundwater contamination attributed to a closed in-place UST, taken out of service in 1986. Diesel and gasoline impacts to both mediums exceeded the ISL standard, and more work was needed to define the extent of contamination. In February 2022, an additional investigation occurred with the placement of permanent groundwater monitoring wells and a program of quarterly groundwater monitoring for one year. Results of the additional work indicate that soil and groundwater contamination remain and is above the ISL standard. The property is a third-party-owned, with the historic RP, Calvinco, taking the lead on site discoveries. The contamination at large, is moderate and the groundwater plume remains primarily on-site, with some impacts to a utility corridor to the south of the source area. The site exceeds the Tier I standard and a supplemental discussion is attached for site closure consideration. RBCA Tier 1 Screening Level Evaluation Groundwater(mg/L)Soil(mg/Kg) Constituent ISL/Tier 1 Level Highest Concentration and Sampling Location ISL/Tier 1 Level Highest Concentration and Sampling Location Benzene 0.005/0.30 <0.005 MW-1 0.20/0.90 0.52 B-2 Toluene 1.0/3.00 <0.012 MW-1 9.0/25.0 0.88 B-2 Ethylbenzene 0.7/4.00 0.959 MW-7 5.0/23.0 18 GP-04 Xylenes 10.0/10.0 2.03 MW-7 142.0/142.0 41.9 GP-04 Napthalene 0.70/0.70 0.724 MW-7 51.0/51.0 13.9 GP-04 MTBE 0.20/0.20 <0.005 MW-1 0.30/0.30 <0.26 MW-2 TPH-gasoline 1.0/10.0 10.6 MW-7 150/1500 1520 GP-04 TPH-diesel 1.0/10.0 7.4 MW-7 500/5000 4600 MW-7 Oil and Grease/TRPH 10.0/10.0 NT NT 1000/10000 NT NT Recommended Tier 1 Actions All contaminant concentration levels are below ISLs or below Tier 1 screening levels and no receptors are within the critical distances. Recommendation - No further action. Tier 1 criteria (contaminant concentration and/or distance to receptors) are exceeded at the site. Recommendation - See attached supplemental information worksheet. Evaluation Completed by:Date: DERR Project Manager's Signature Utah's RBCA Tier 1 Worksheet Printed on: 11/18/2024 7:04:41 AM 11/18/2024 SUPPLEMENTAL INFORMATION FOR NO FURTHER ACTION Former Pyramid Oil Co. at Intermountain Lock and Supply 3120 South Main Street, South Salt Lake, Utah Facility Identification No. 4000124, Release Site OBL Facility History and Contaminant Source Elimination and Control In April 2021, a realty-styled subsurface investigation revealed soil and groundwater contamination attributed to a closed in-place, 3,000-gallon, underground storage tank (UST) taken out of service in 1986. Diesel and gasoline impacts exceeded the Division of Environmental Response and Remediation (DERR) Initial Screening Level (ISL) standard and more work was needed to define the extent of the contamination. In July 2021, Release ID ‘OBL’ was assigned to the site. Site history indicates that petroleum operations on the property at large, about 100 feet northwest of the former UST, included an aboveground storage tank (AST) bulk plant, owned by the Pyramid Oil Company (Pyramid) from about 1958 through 1985, with the ASTs being removed in about 1985. The area of the former UST was located on the corner of Main Street and Angelo Avenue where it supported a corner service station. The UST, owned by Calvinco Company (Calvinco) and operated by Pyramid, was closed in-place in 1986. In the early 1990s, Intermountain Lock and Supply (IML) bought the property and built the commercial office building that is currently on site (see Figures: 1-Site Location Map, 1A-Aerial Map, 1B-Aerial Map-1964). In March 2006, DERR inspectors responded to a report of petroleum-impacted soils from a public works crew replacing a 10" water line under Angelo Avenue, between Main Street and West Temple Street. Weathered, diesel-impacted soils were encountered from about 1-5 feet below grade (bg), the trench depth, and along a 100 foot stretch of the waterline’s trench. The most impacted soil was reported near the corner of Main Street and Angelo Avenue, with diminishing impacts westward. Diesel-impacted soils removed from the trench were sent to an approved landfill. DERR Facility ID 4002382 and Release MBO was assigned as an ‘Unknown’ facility, with a DERR internal closure occurring April 2006 (see Figure 1C-Waterline Work 2006). In April 2021, a subsurface investigation was performed by Western Geologic (WG) at IML to evaluate the closed UST. Five direct-push locations, GP-01 through GP-5, were advanced near and downgradient from the UST; collected environmental samples were by a non-certified sampler. Soil at GP-01, GP-02 and GP-04 exceeded the ISL standard for total petroleum hydrocarbons gasoline range organics (TPH-GRO), and for total petroleum hydrocarbons diesel range organics (TPH-DRO) at GP-02. At GP-04, ethyl-benzene exceeded the ISL standard. Groundwater sampling results showed exceedances of the ISL standard at GP-01 and GP-04 for TPH-GRO, and for TPH-DRO at GP-01, GP-02 and GP-04. At GP-04 and GP-05, benzene exceeded the ISL standard while ethyl- benzene exceeded the ISL standard at GP-01 and GP-04 (see Figure 1-UEC and WG Table 1 and WG Table 2). In February 2022, additional investigations by Underwood Environmental Consulting (UEC) began with the emplacement of two soil borings, B-1 and B-2, and four groundwater monitoring wells (MW), MW-1 through MW-4, followed by groundwater monitoring. Results of the soil analyses work indicated that soil at MW-2 and B-2, exceeded the ISL standard for TPH-GRO, TPH-DRO and benzene. Soil at MW-2 also exceeded the ISL standard for ethyl-benzene (see Figure 1-UEC and Table 1-UEC (Soil)). From March 2022 through December 2022, four groundwater monitoring events occurred and results showed ongoing exceedances of the ISL standard for TPH-DRO, TPH-GRO, and ethyl-benzene at MW-1, MW-2 and MW-3 (see Figure 1-UEC and Table 1-UEC (GW)). In May 2023 following a DERR Closure Committee review and comment letter to Calvinco , MW-5, MW-6 and MW-7 were added to MW network, and in September 2024, a sub-slab vapor study was performed near the IML building. Results of the MW emplacement showed that soil at MW-7, exceeded the ISL standard for TPH-DRO and TPH-GRO, and that groundwater sampling results for MW-7 showed exceedances of TPH-DRO, TPH-GRO and ethyl-benzene (see Figure 1-UEC and Table 1-UEC (Soil) and Table 1-UEC (GW)). Following the MW installation and groundwater sampling in May 2023 one additional groundwater sampling event took place, November 2023. Results of groundwater sampling for all events, March 2022 to November 2023, show ongoing impacts to groundwater above the ISL standard at MW-1, MW-2, MW-3 and MW-7 for TPH-GRO and TPH-DRO; MW-1 and MW-7 showed ongoing impacts from ethyl-benzene and MW-7 had naphthalene above the ISL standard (see Figure 1-UEC and Table 1-UEC (GW)). In September 2024, a sub-slab soil gas study was performed in the parking lot near the IML building. Sampling point SV-01 was placed near MW-5 and the entrance to a subgrade parking garage, and SV-02 was placed near GP-02/MW-7 and the entrance to the IML building. Results of the soil gas study showed that no chemicals of concern; benzene, toluene, ethyl-benzene, xylene or naphthalene (BTEXN), were exceeded compared to EPA’s Target Sub-Slab and Near-source Soil Gas Concentration Vapor Intrusion Screening Levels (VISLs) for Residential and Commercial land use scenarios (see Figure 1-UEC and Table 1-UEC (Soil Vapor Study)). Thus, UST site history beginning in about 1956, includes the operation of a 3,000-gallon UST that fueled a corner service station, the in-place closure of the UST in 1986, and the discovery of petroleum impacted soil and groundwater in February 2021. No work has been done to clean-up the petroleum impacts and soil and groundwater contamination that remains exceeds the ISL standard at the closed UST, down gradient from it, and near a utility corridor. Because remaining soil and groundwater contamination exceeds the ISL standard and the distance criteria to several receptors, Release ‘OBL’ needs further review. The following discussion of the impacts of remaining contamination to public health and the environment is presented, with a recommendation for no further action (NFA), coupled with an in-place contamination map and notification to the Blue Stakes of Utah network. Current Land Use Current land use is commercial. The property contains an office building with parking lot. Nature and Extent of Contamination The nature of the contamination is diesel and gasoline associated with a closed in-place UST. The highest levels of remaining soil contamination are found at sampling locations GP-04, B-2 and MW-7, existing from about 8 feet to 12 feet bg. The footprint of the contaminant plume is about 5,400 square feet (sf), and includes the area of the closed UST and its groundwater plume that is about 115 feet long by 60 feet wide. Groundwater at about 9’ bg, has a gradient of 0.003 ft/ft, and trends west-northwest. The highest groundwater impacts at the site are found at MW-1, MW-2, MW-3 and MW-7. The groundwater plume terminates to the northwest between MW-3 and MW-4, and remains on the subject property. Groundwater impacts along the southern flank of the plume are assumed under Angelo Avenue, near MW-2, and diminish westward near GP-05. Although the soil and groundwater contamination along the southern boundary at Angelo Avenue, i.e., B-2 and MW-2 could be better defined, results of the waterline replacement work in 2006, suggests that petroleum impacted soils were removed from a 100’ section of the trench, from the corner of Angelo Avenue and Main Street, to points west, where contamination was noted as diminished. Southeast of the source area, i.e., GP-01 and B-1, soil or groundwater was not sampled, as numerous utilities exist, making sampling difficult at the corner location. An evaluation of the existing soil and groundwater data indicates increasing amounts of petroleum contamination from the UST source area to areas west, suggesting that additional sampling upgradient is not warranted at this time. The contamination at large represents degraded fuel with soil impacts above the ISL standard on-site and the surrounding utility corridor at Angelo Avenue and Main Street (see Figure 2, Plume Boundary Map). Impact of Remaining Contamination on Public Health and the Environment Several exposure pathways to the remaining contamination exist, and can be controlled to reduce exposure risks. The greatest risk to exposure would be the construction worker, who could encounter petroleum contamination if soils or groundwater are disturbed. Soil-Leaching-to-Groundwater and Groundwater Ingestion Exposure Pathway Soil based contamination has leached to groundwater, but the remaining contamination should not contribute to an increase in the mass of the groundwater plume. Soils remaining above the ISL standard are found at GP-01, GP-04, B-2, MW-2 and MW-7. The groundwater plume above the ISL standard is primarily beneath the parking lot and landscaped areas of the IML facility, at a depth of about 9’ bg, and found at MW-1, MW-2, MW-3 and MW-7. Various utilities such as a storm drain system, waterlines and deeper sewer conduits surround the east and south boundaries of the site, and pose the greatest risk for exposure to the remaining contamination. The construction worker is most likely to encounter petroleum-impacted groundwater if it is disturbed. A 500’ radius search for points of diversion was performed using the Utah Division of Water Rights (DWR) database. One municipal water source, Water Right (WR) #57-10223 exits 190’ due east and upgradient to the site. The well is associated with the Jordan Valley Water Conservation District system, using a series of shallow groundwater wells drawing from about 10’ to 100’ bg. It is not expected to be impacted due to its drawdown of local groundwater. Groundwater monitoring at the site indicates an ongoing west-northwest trend in groundwater movement with no apparent hydraulic drawdown from the east. WR #57-4620 is 455’ east and upgradient to the site, is an irrigation well dating to 1926 and is likely abandoned. A domestic well, WR# 57-43389, is 502’ southwest of the site and is dated to 1935, with updated ownership records in 2017. The wells depth is 250’ bg and not expected to be impacted by the onsite shallow groundwater plume (see Attachment ‘A’ for DWR Radius Search). Site-Specific Cleanup Levels (SSCLs) and Groundwater Ingestion SSCLs were determined for the remaining soil and groundwater contamination at GP-02, due to its proximity to the IML building, and at MW-01(groundwater) and B-2(soil), for plume core and utility corridor concerns, respectively. Input values include, a commercial setting, groundwater at 9’ bg and the presence of silty sand. Regarding analytic data, MBTEXN, TPH-GRO values (C5 -C10 range constituents) and TPH-DRO values (C11 - C16 range constituents) were utilized. At GP-02, SSCL calculations show that soil failed the ‘Subsurface Soil Leaching to Groundwater’, the ‘Subsurface Soil to Indoor Air’ and the ‘Subsurface Soil to Outdoor Air’ pathways for benzene, several alkyl groups, PAH and numerous aliphatics. Of note is that the input value for benzene is below the ISL and the laboratory detection level used, <0.15 mg/kg. However, the September 2024 soil gas study performed near GP- 02/MW-7 showed that no chemicals of concern, BTEXN, were exceeded compared to the EPA’s VISLs for Residential and Commercial land use scenarios. At MW-01, SSCL calculations show that groundwater failed the ‘Groundwater Ingestion’ pathway for several alkyl groups, PAH and numerous aliphatics. At B-2, SSCL calculations show that soil failed the ‘Subsurface Soil Leaching to Groundwater’, the ‘Subsurface Soil to Indoor Air’ and the ‘Subsurface Soil to Outdoor Air’ pathways for benzene, naphthalene, several alkyl groups, PAH and numerous aliphatics. Regarding the ‘Groundwater Ingestion’ pathway, there is no use of the groundwater at the site. Only the construction worker scenario should be considered for potential groundwater ingestion. A discussion of the other completed exposure pathways, is presented below (see Attachment B-1 and B-2 for SSCL calculations). Vapor-Intrusion-to-Indoor Air Exposure Pathway Vapor intrusion to indoor air is possible, according to the SSCL calculus at GP-02 and B-2, but the September 2024 soil gas study provided real-time data that showed no EPA VISLs were exceeded near the IML building, at GP-02/MW-7. As such, concerns for vapor intrusion at B-2 and the utility corridor at Angelo Avenue, may be reduced, but possible as a confined space issue, potentially affecting construction workers. Risks to construction workers can be mitigated by placing the surrounding utility corridor on the Blue Stakes of Utah network. Vapor-Intrusion-to-Outdoor Air Exposure Pathway Vapor intrusion to outdoor air is possible according to the SSCL calculus at GP-02 and B-2. At GP-02, landscaping is in and about the area, with concrete parking to the south. There, outdoor air exposure scenarios would likely include landscape workers with short exposure periods, or construction workers, if impacted soils are disturbed below 8’ bg. At B-2, landscaping is present as an elevated bed with trees, and south of it is a public sidewalk and the utility corridor at Angelo Avenue. Outdoor air exposure scenarios would include landscape workers, or construction workers, if impacted soils are disturbed below 8’ bg. Risks to construction workers can be mitigated by placing the surrounding utility corridor on the Blue Stakes of Utah network. Surface Soil Exposure Pathway: Dermal Contact, Particulate Inhalation and Ingestion, and Construction Worker Dermal contact, particulate inhalation and ingestion are only possible via the construction worker scenario at the site, and the utility corridor at Angelo Avenue. Petroleum-affected soils from about 8’ to 12’ bg, are primarily covered with asphalt or concrete, with areas of landscaping. Risks to construction workers can be mitigated, first by IML, who controls access and activities at the site, and by placing the surrounding utility corridor on the Blue Stakes of Utah network. Other: Exposure Pathways-Utility Lines Soil and groundwater contamination potentially affecting utility lines or workers is found within the contaminant plume, which exists from GP-01 on the east to areas west of MW-3, along its axis, and from GP-02/MW-7 on the north to Angelo Avenue on the south, near B-2 and MW-2. The contaminant plume is from 8’ to 12’ bg and poses no imminent threat to human health or the environment. Sensitive utilities, such as drinking water and sanitary sewer layouts, exist surrounding the site at Main Street and Angelo Avenue, with some impacted soil removed from a 2006 water line replacement beneath Angelo Avenue. Utilities that support the IML building are sewer and drinking water lines, found north and outside the plume boundary, and communications and natural gas lines that parallel the south side of the building, near GP-02/MW-7. Electric lines are subgrade and are found outside the plume near MW-4. Only under the construction worker scenario could the remaining petroleum-impacted media be encountered. Risks to construction workers can be mitigated, first by IML, who controls access and activities at the site, and by placing the surrounding utility corridor on the Blue Stakes of Utah network (see Attachment C for Utility Map). Economic Considerations and Cost-Effectiveness of Cleanup Options Considering the economics of cleanup for this release is one of cost versus threat. In this case, the potential costs of treating soil by removal, and long-term groundwater monitoring, could exceed a half million dollars. The risks of exposure to the soil and groundwater contamination exists for the construction worker scenario only. At large, the constituents of concern that remain are TPH-GRO, TPH-DRO, benzene and ethyl-benzene. There is a low risk to leaving the contamination in-place. Requiring additional investigations or cleanup is unnecessary. Precautions for exposure to impacted soil or groundwater can be managed by IML, the landowner and Blue Stakes awareness near the utility corridor. Technology Available for Cleanup The technology does exist for the cleanup of the ‘Former Pyramid Oil Co.’ release site. Removal of soil contamination is the best option for treatment at the site, and groundwater could be treated or monitored to attenuation. But the lack of any on-going threat to public health or the environment, excepting the construction worker, suggests this petroleum release be closed of concern. Recommendation for No Further Action It is recommended that the petroleum contamination associated with the ‘Former Pyramid Oil Co.’ release site be closed of concern and that NFA status be granted to DERR Release ‘OBL’. A leaking UST was closed in-place in 1986, and soil and groundwater contamination exists in situ. The release has been evaluated, including threats of remaining contamination to public health and the environment. A review of soil and groundwater data and of sensitive receptors in the area suggests that only under the construction worker scenario, is petroleum contaminated soil or groundwater to be encountered at the site. A NFA letter, coupled with an in-place contamination map and notification to the Blue Stakes of Utah network, should be issued to Calvinco. FIGURES 1-Site Location Map 1A-Aerial Map 1B-Aerial Map-1964 1C-Waterline Work 2006 1-UEC- Environmental Sampling Map 2-Plume Boundary Map Figure 1: Site Location Map 0 0.2 0.4mi N S W E Figure 1A Aerial Map (2018) 0 100 200ft N S W E Figure 1B Aerial Map (1964) Blue shaded area is the former Calvinco UST and Service Station. Figure 1C Waterline Work 2006 0 30 60ft N S W E LEGEND approx. scale in feet one inch ~ 30 feet 00 3015 Former Calvinco Co. (Intermountain Lock) 3106 South Main St. South Salt Lake, Utah Facility ID # 4000124 Release Site OBL NORTH W SD Natural Gas Water Line G W S (Utility Locations Approximate) Power or Unknown SD Storm Drain CommunicationsC P Sanitary Sewer U GG C S U P SD SD C W C C U S S SD P U U Ma i n S t r e e t Angelo Avenue Intermountain Lock Security Supply Closed-in-Place Diesel UST Gr a c e M a r y M a n o r FIGURE 110/04/2024 MW-2 Monitoring Well B-1 Soil Boring Soil Boring (Western Geologic, 2021b) GP-01 91.17 Groundwater Elev. (ft) 9 1 Groundwater Contour Line (contour interval = 0.1 ft) Groundwater Flow Direction Soil Vapor Sample Locations September 13, 2024 B-2 B-1 GP-01 GP-02GP-03 GP-04 GP-05 MW-3 MW-1 MW-2 MW-4 MW-6 MW-5 MW-7 V V V Soil Vapor Sample Point SV-01-West SV-02-East Figure 2 Approximate Plume Boundary Map Tables WG Table 1 and WG Table 2 Table 1-UEC (Soil) Table 1-UEC (GW) Table 1-UEC (Soil Vapor Study) Western Geologic Table 1 (sampled 4-26-2021) Western Geologic Table 2 (sampled 4-26-2021) Subsurface Investigation Report #2 Former Calvinco Co. - IML 3106 South Main St., South Salt Lake, UT Facility ID #4000124, Release Site OBL Date Ethyl-Total Naphtha-TPH TPH Sample Number Collected MTBE Benzene Toluene benzene Xylenes lene GRO DRO (mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg) MW-1 @ 4-5'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.286 <57 MW-1 @ 6.5-7.5'2/23/2022 <0.01 <0.01 <0.03 1.29 0.49 1.22 79.7 222 MW-1 @ 11-12'2/23/2022 <0.01 <0.01 <0.03 0.08 0.41 0.15 2.39 <64 MW-2 @ 4-5'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.308 <62 MW-2 @ 6-7'2/23/2022 <0.01 <0.01 <0.03 0.51 0.37 3.49 106 337 MW-2 @ 8-9'2/23/2022 <0.01 <0.01 <0.03 0.03 <0.03 0.46 224 935 MW-2 @ 11-12'2/23/2022 <0.26 <0.26 <0.66 9.38 <0.66 3.08 541 342 MW-3 @ 4-5'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.294 <59 MW-3 @ 9-10'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 1.84 157 MW-3 @ 12-13'2/23/2022 <0.01 <0.01 <0.03 0.55 1.44 0.22 29.0 141 MW-4 @ 4-5'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.296 <59 MW-4 @ 6-7'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.295 <59 MW-4 @ 8-9'2/23/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.309 <62 B-1 @ 4.5-5'2/24/2022 <0.01 <0.01 <0.03 <0.03 <0.03 0.04 0.638 <57 B-1 @ 9-10'2/24/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 2.67 <58 B-1 @ 11-12'2/24/2022 <0.01 <0.01 <0.03 0.10 0.03 0.60 61.9 263 B-2 @ 4-5'2/24/2022 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.285 <57 B-2 @ 9-10'2/24/2022 <0.24 0.52 0.88 2.76 2.48 3.74 632 1,820 B-2 @ 10.5-11.5'2/24/2022 <0.01 <0.01 <0.03 0.81 0.48 0.65 43.9 301 0.3 0.2 9 5 142 51 150 500 0.3 0.9 25 23 142 51 1,500 5,000 continued next page TABLE 1 SOIL SAMPLE ANALYTICAL RESULTS Tier 1 Screening Criteria (1) Initial Screening Level (1) Underwood Environmental Consulting, Inc. Subsurface Investigation Report #2 Former Calvinco Co. - IML 3106 South Main St., South Salt Lake, UT Facility ID #4000124, Release Site OBL Date Ethyl-Total Naphtha-TPH TPH Sample Number Collected MTBE Benzene Toluene benzene Xylenes lene GRO DRO (mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg) TABLE 1 SOIL SAMPLE ANALYTICAL RESULTS MW-5 @ 7-8'5/16/2023 <0.01 <0.01 <0.02 <0.02 <0.02 <0.02 <0.243 <60 MW-5 @ 10-11'5/16/2023 <0.13 <0.13 <0.31 <0.31 <0.31 <0.31 133 72 MW-5 @ 12.5-13'5/16/2023 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.315 <63 MW-6 @ 6-7'5/16/2023 <0.008 <0.008 <0.02 <0.02 <0.02 <0.02 <0.193 <57 MW-6 @ 10-11.5'5/16/2023 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.331 <66 MW-6 @ 13-14'5/16/2023 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.318 <64 MW-7 @ 6-7'5/16/2023 <0.01 <0.01 <0.03 <0.03 <0.03 <0.03 <0.264 <57 MW-7 @ 8-9.5'5/16/2023 <0.13 <0.13 <0.31 <0.31 <0.31 <0.31 1,430 4,600 MW-7 @ 12-13'5/16/2023 <0.13 <0.13 <0.34 4.38 2.78 6.22 543 98 0.3 0.2 9 5 142 51 150 500 0.3 0.9 25 23 142 51 1,500 5,000 Notes:MTBE = Methyl Tertiary-Butyl Ether mg/kg = Milligrams per kilogram TPH-GRO =Total Petroleum Hydrocarbons - Gasoline Range Organics < Indicates below given detection limit TPH-DRO =Total Petroleum Hydrocarbons - Diesel Range Organics (1) DERR, 2005 Bold values are above Initial Screening Levels Highlighted, bold , values are above Tier 1 Screening Criteria Tier 1 Screening Criteria (1) Initial Screening Level (1) Underwood Environmental Consulting, Inc. Groundwater Monitoring Report - November 2023 Former Calvinco Co. - IML 3106 South Main St., South Salt Lake, UT Facility ID 4000124, Release Site OBL WELL/DATE DTW GW Elev.MTBE Benzene Toluene Ethyl- benzene Xylenes Naphth- alene TPH (GRO) TPH (DRO)ELEV.(feet)(feet)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L) MW-1 03/04/22 9.29 90.71 <0.005 <0.005 0.012 1.68 4.84 0.488 7.92 7.7 100.00 06/11/22 9.36 90.64 <0.005 <0.005 0.014 1.94 6.49 0.500 19.0 7.9 09/11/22 10.24 89.76 <0.005 <0.005 <0.012 0.954 3.84 0.447 21.7 5.6 12/10/22 9.41 90.59 <0.005 <0.005 <0.012 0.901 1.69 0.340 22.4 5.6 05/28/23 8.86 91.14 <0.005 <0.005 0.012 1.61 6.08 0.441 15.6 6.3 11/12/23 9.78 90.22 <0.005 <0.005 <0.012 0.700 1.17 0.426 6.28 3.3 MW-2 03/04/22 7.80 90.72 <0.005 <0.005 <0.012 0.353 0.057 0.220 8.20 6.5 98.52 06/11/22 7.88 90.64 <0.005 <0.005 <0.012 0.239 0.036 0.126 11.3 8.9 09/11/22 8.88 89.64 <0.005 <0.005 <0.012 0.442 0.033 0.150 13.1 4.4 12/10/22 7.91 90.61 <0.005 <0.005 <0.012 0.850 0.038 0.132 24.4 4.7 05/28/23 7.35 91.17 <0.005 <0.005 <0.012 0.223 0.016 0.111 6.22 4.9 11/12/23 8.42 90.10 <0.005 <0.005 <0.012 0.618 0.024 0.138 4.45 3.0 MW-3 03/04/22 9.18 90.69 <0.005 <0.005 0.038 1.98 3.61 0.502 15.0 8.5 99.87 06/11/22 9.27 90.60 <0.005 <0.005 <0.012 0.636 1.09 0.101 6.85 3.7 09/11/22 10.41 89.46 <0.005 <0.005 0.015 0.952 1.13 0.261 12.6 3.8 12/10/22 9.33 90.54 <0.005 <0.005 <0.012 0.472 0.530 0.069 14.8 2.2 05/28/23 8.59 91.28 <0.005 <0.005 <0.012 0.048 0.067 0.019 1.03 <1.0 11/12/23 9.87 90.00 <0.005 <0.005 <0.012 0.373 0.342 0.061 2.05 1.3 MW-4 03/04/22 7.98 90.12 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 0.266 <1.0 98.10 06/11/22 7.92 90.18 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 <0.125 <1.0 09/11/22 8.92 89.18 0.036 <0.005 <0.012 <0.012 <0.012 <0.012 <0.125 <1.0 12/10/22 7.78 90.32 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 0.645 <1.0 05/28/23 7.21 90.89 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 <0.125 <1.0 11/12/23 8.63 89.47 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 <0.125 <1.0 MW-5 05/28/23 6.94 91.20 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 0.806 <1.0 98.14 11/12/23 8.36 89.78 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 <0.125 <1.0 MW-6 05/28/23 8.96 91.27 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 0.593 <1.0 100.23 11/12/23 10.27 89.96 <0.005 <0.005 <0.012 <0.012 <0.012 <0.012 <0.125 <1.0 MW-7 05/28/23 10.02 91.23 <0.005 <0.005 <0.012 0.780 1.42 0.375 10.9 8.0 101.25 11/12/23 11.05 90.20 <0.005 <0.005 <0.012 0.959 2.03 0.724 10.6 7.4 Initial Screening Levels (1)0.2 0.005 1 0.7 10 0.7 1 1 Tier 1 Screening Criteria (1)0.2 0.3 3 4 10 0.7 10 10 Notes:Arbitrary datum of 100.00 feet established on site.TPH (GRO) = Total Petroleum Hydrocarbons - Gasoline Range Organics DTW = Depth to Water TPH (DRO) = Total Petroleum Hydrocarbons - Diesel Range Organics GW Elev. = Groundwater Elevation < Indicates below given detection limit. MTBE = Methyl Tertiary Butyl Ether Bold values are above Initial Screening Levels. mg/L = Milligrams per Liter Highlighted,bold , values are above Tier 1 Screening Criteria. (1) DERR, 2005 TABLE 1 GROUNDWATER MONITORING DATA Underwood Environmental Consulting, Inc. Soil Vapor Sampling Report - September 2024 IML - Former Calvinco Co. Facility ID #4000124, Release Site OBL Well /Sample Sample MTBE Benzene Toluene Ethyl-Total Naphthalene TPH Sample Date Depth benzene Xylenes Name (ft bgs)(µg/m3)(µg/m3)(µg/m3)(µg/m3)(µg/m3)(µg/m3)(µg/m3) SV-01-West 9/13/2024 ~0.75 <0.59 3.2 6.6 2.0 14.4 <1.7 110 SV-02-East 9/13/2024 ~0.75 <0.70 3.3 5.6 1.7 12.3 <2.0 97 DERR SSCL Calculator, sub-slab, commercial 146000 16.4 243667 49333 4933 146 NE Notes:MTBE = methyl tertiary butyl ether TPH = total petroleum hydrocarbons ft bgs = feet below ground surface < = below given detection limit. µg/m 3 = micrograms-per-cubic meter NE = not established Bold values, if any, indicate a concentration greater than DERR SSCL Calculator, sub-slab, commercial regulatory guidance (DERR, 2015). TABLE 1 SOIL VAPOR ANALYTICAL RESULTS Underwood Environmental Consulting, Inc. ATTACHMENTS Attachment: A-DWR Radius Search Attachment: B-1 and B-2-SSCL Calculations Attachment: C-Utility Map Attachment A: DWR Points of Diversion Map 0 100 200ft N S W E Page 1 of 3SSCL Calculator Prepared for: SSCL Calculator Prepared by: Site name: Site address: Facility ID: Release ID: Contact name: Contact phone: Contact e-mail: Site-Specific Cleanup Levels* for Commercial/ Industrial Receptors Air Groundwater Soil SSCLair SSCLwing SSCLwesp SSCLwamb SSCLs-leach SSCLsesp SSCLsamb SSCLss (See Eq. D.1) (See Eq. D.2) (See Eq. D.3)(See Eq. D.4) (See Eq. D.5) (See Eq. D.6) (See Eq. D.7) (See Eq. D.8) Air Groundwater Groundwater Groundwater Subsurface soil Subsurface soil Subsurface soil Surface Soil Inhalation Ingestion Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Leaching to groundwater (groundwater ingestion) Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Ingestion of soil, inhalation of vapors and particles, and dermal contact µg/m3 air µg/m 3 air mg/L water mg/L water mg/L water mg/L water mg/kg soil mg/kg soil mg/kg soil mg/kg soil mg/kg soil Benzene (71-43-2) c 4.93E-01 0.297 SG-1 7/28/2011 (slab atten. factor *0.03)9.87E-03 7.20E-01 1.87E+02 0.001 GP-02@7-10'5.64E-02 3.50E-03 1.31E-01 5.69E+00 0.15 GP-02@7-10' Toluene (108-88-3) nc 7.31E+03 1.291 SG-1 7/28/2011 (slab atten. factor *0.03)8.18E+00 1.20E+04 3.15E+06 0.001 GP-02@7-10' 7.52E+01 7.02E+01 2.63E+03 5.40E+03 0.748 GP-02@7-10' Ethylbenzene (100-41-4) nc 1.48E+03 0.150 SG-1 7/28/2011 (slab atten. factor *0.03)1.02E+01 2.68E+03 7.03E+05 0.001 GP-02@7-10' 1.63E+02 2.17E+01 8.10E+02 6.47E+03 0.15 GP-02@7-10' Xylenes (1330-20-7) nc 1.48E+02 0.571 SG-1 7/28/2011 (slab atten. factor *0.03)2.04E+01 2.37E+02 6.17E+04 0.003 GP-02@7-10' 3.31E+02 2.98E+00 1.11E+02 6.57E+03 0.449 GP-02@7-10' Naphthalene (91-20-3) nc 4.39E+00 0.300 SG-1 7/28/2011 (slab atten. factor *0.03)2.04E+00 1.23E+01 2.30E+03 0.005 GP-02@7-10' 4.03E+01 2.07E+00 7.74E+01 3.63E+02 0.748 GP-02@7-10' MTBE (1634-04-04) nc 4.38E+03 0.150 SG-1 7/28/2011 (slab atten. factor *0.03)5.11E-01 2.90E+03 2.47E+05 0.001 GP-02@7-10' 1.44E+00 1.59E+02 5.95E+03 3.40E+02 0.15 GP-02@7-10' Alkyl benzenes (C9-C10) [average values]nc 3.07E+02 4.09E+00 5.76E+02 1.51E+05 0.5 GP-02@7-10'1.27E+02 9.31E+00 3.48E+02 2.47E+03 486 GP-02@7-10' Alkyl naphthalenes (C11-C13) [average values]nc 3.07E+02 4.09E+00 8.25E+02 1.57E+05 1.82 GP-02@7-10'5.98E+02 9.97E+02 3.73E+04 1.17E+04 961 GP-02@7-10' Total PAHs (C12-C22) [average values]nc 1.53E+02 3.07E+00 1.39E+02 3.45E+04 1.82 GP-02@7-10' 3.94E+03 3.64E+02 1.36E+04 7.15E+03 961 GP-02@7-10' Aliphatics (C5-C6) [Hexane (110-54-3)]nc 3.07E+02 0.270 SG-1 7/28/2011 6.13E+00 5.08E+02 1.36E+05 0.5 GP-02@7-10' 1.96E+03 6.85E-01 2.56E+01 3.54E+03 486 GP-02@7-10' Aliphatics (C7-C8) [Heptane (142-82-5)]nc 3.07E+02 0.282 SG-2 1/10/2013 (slab atten. factor *0.03)6.13E+00 6.14E+02 1.64E+05 0.5 GP-02@7-10' 3.92E+03 9.33E-01 3.49E+01 3.54E+03 486 GP-02@7-10' Aliphatics (C9-C10) [Nonane (111-84-2)]nc 1.48E+03 0.390 SG-2 1/10/2013 (slab atten. factor *0.03)1.02E+01 3.47E+03 9.27E+05 0.1 GP-02@7-10' 1.87E+04 6.47E+00 2.42E+02 6.47E+03 486 GP-02@7-10' Aliphatics (C11-C12) [Undecane (1120-21-4)]nc 1.48E+03 1.02E+01 3.94E+03 1.05E+06 8.17 GP-02@7-10' 7.79E+04 3.77E+01 1.41E+03 6.47E+03 961 GP-02@7-10' Aliphatics (C13-C16) [Hexadecane (544-76-3)]nc 1.48E+03 1.02E+01 4.55E+03 1.22E+06 8.17 GP-02@7-10' 1.05E+06 5.93E+02 2.22E+04 6.47E+03 961 GP-02@7-10' Aliphatics (C17-C21) [Heptadecane (629-78-7)]nc 1.02E+04 2.04E+02 3.75E+04 1.00E+07 8.17 GP-02@7-10' 1.67E+09 5.66E+05 2.12E+07 1.29E+05 961 GP-02@7-10' Aliphatics (C22-C35) [Heptadecane (629-78-7)]nc 1.02E+04 2.04E+02 3.75E+04 1.00E+07 8.17 GP-02@7-10' 1.67E+09 5.66E+05 2.12E+07 1.29E+05 961 GP-02@7-10' Mark Crim DEQ/ERR Date prepared:1/10/2023 Former Pyramid Oil Company at IML 3120 South Main Street, South Salt Lake, Utah 4000124 OBL Soil Comments (e.g. Sample ID, Sample Depth, Sample Date, etc.) Highest Soil Concentrations Remaining at the Site Name: Company, Agency, other: Phone: E-mail: UST Consultant Cert. #: Highest Air Concentrations Remaining at the Site Air Comments (e.g. Sample ID, Sample Date, etc.) Groundwater Comments (e.g. Sample ID, Sample Date, etc.)Chemical Name (CAS #) Pr i m a r y C h e m i c a l s o f C o n c e r n To t a l P e t r o l e u m H y d r o c a r b o n F r a c t i o n s Highest Groundwater Concentrations Remaining at the Site SSCL.OBL.GP-02 Page 1 of 3 1/13/2023 9:31 AM Page 2 of 3Site-Specific Cleanup Levels* for Commercial/ Industrial Receptors Air Groundwater Soil SSCLair SSCLwing SSCLwesp SSCLwamb SSCLs-leach SSCLsesp SSCLsamb SSCLss (See Eq. D.1) (See Eq. D.2) (See Eq. D.3)(See Eq. D.4) (See Eq. D.5) (See Eq. D.6) (See Eq. D.7) (See Eq. D.8) Air Groundwater Groundwater Groundwater Subsurface soil Subsurface soil Subsurface soil Surface Soil Inhalation Ingestion Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Leaching to groundwater (groundwater ingestion) Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Ingestion of soil, inhalation of vapors and particles, and dermal contact µg/m3 air µg/m 3 air mg/L water mg/L water mg/L water mg/L water mg/kg soil mg/kg soil mg/kg soil mg/kg soil mg/kg soil Soil Comments (e.g. Sample ID, Sample Depth, Sample Date, etc.) Highest Soil Concentrations Remaining at the Site Highest Air Concentrations Remaining at the Site Air Comments (e.g. Sample ID, Sample Date, etc.) Groundwater Comments (e.g. Sample ID, Sample Date, etc.)Chemical Name (CAS #) Highest Groundwater Concentrations Remaining at the Site Acenaphthylene (208-96-8)nc 1.53E+02 3.07E+00 1.29E+03 1.09E+05 1.80E+02 1.48E+03 5.54E+04 7.75E+03 Acenaphthene (83-32-9)nc 8.69E+01 6.13E+00 5.68E+02 5.54E+04 3.12E+02 5.24E+02 1.96E+04 6.01E+03 Fluorene (86-73-7)nc 5.62E+01 4.09E+00 5.78E+02 4.23E+04 3.35E+02 9.81E+02 3.67E+04 5.54E+03 Phenanthrene (85-01-8)nc 1.53E+02 3.07E+00 3.75E+03 1.91E+05 5.16E+02 1.46E+04 5.45E+05 1.18E+04 Anthracene (120-12-7)nc 4.38E+02 3.07E+01 9.05E+03 4.84E+05 4.88E+03 3.28E+04 1.23E+06 6.86E+04 Fluoranthene (206-44-0)nc 5.83E+01 4.09E+00 4.62E+03 1.83E+05 2.32E+03 6.38E+04 2.39E+06 1.57E+04 Pyrene (129-00-0)nc 4.38E+01 3.07E+00 4.31E+03 1.63E+05 1.61E+03 5.55E+04 2.07E+06 1.20E+04 Benz(a)Anthracene (56-55-3)c 1.96E-01 3.92E-04 1.62E+01 6.08E+02 8.15E-01 8.24E+02 3.08E+04 2.00E+00 Chrysene (218-01-09)c 1.96E+00 3.92E-02 4.22E+02 1.51E+04 6.51E+01 1.73E+04 6.48E+05 1.94E+02 Benzo(b)Fluoranthene (205-99-2)c 1.96E-02 3.92E-04 1.06E+00 4.67E+01 6.64E-01 4.28E+01 1.60E+03 1.88E+00 Benzo(k)-Fluoranthene (207-08-09)c 1.96E-01 3.92E-03 7.02E+02 2.35E+04 9.67E+00 4.32E+04 1.62E+06 2.00E+01 Benzo(a)-Pyrene (50-32-8)c 2.35E-03 3.92E-05 2.29E+00 7.71E+01 1.05E-01 1.52E+02 5.70E+03 1.99E-01 Indeno(1, 2, 3-Cd)Pyrene (193-39- 5)c 2.35E-02 3.92E-04 1.36E+03 8.68E+03 6.48E-02 5.53E+03 3.95E+04 1.98E+00 Dibenzo-(a, h)Anthracene (53-70- 3)c 2.35E-02 3.92E-04 5.28E+01 1.77E+03 5.92E+00 1.99E+04 7.43E+05 2.00E+00 Benzo (g, h, i)-Perylene (191-24-2)nc 1.53E+02 3.07E+00 9.37E+04 3.21E+06 1.94E+04 1.48E+07 5.52E+08 1.56E+04 Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Ad d i t i o n a l C h e m i c a l s o f C o n c e r n (c a r c i n o g e n t s ) In d i v i d u a l P o l y n u c l e a r A r o m a t i c H y d r o c a r b o n s ( P A H s ) SSCL.OBL.GP-02 Page 2 of 3 1/13/2023 9:31 AM Page 3 of 3Site-Specific Cleanup Levels* for Commercial/ Industrial Receptors Air Groundwater Soil SSCLair SSCLwing SSCLwesp SSCLwamb SSCLs-leach SSCLsesp SSCLsamb SSCLss (See Eq. D.1) (See Eq. D.2) (See Eq. D.3)(See Eq. D.4) (See Eq. D.5) (See Eq. D.6) (See Eq. D.7) (See Eq. D.8) Air Groundwater Groundwater Groundwater Subsurface soil Subsurface soil Subsurface soil Surface Soil Inhalation Ingestion Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Leaching to groundwater (groundwater ingestion) Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Ingestion of soil, inhalation of vapors and particles, and dermal contact µg/m3 air µg/m 3 air mg/L water mg/L water mg/L water mg/L water mg/kg soil mg/kg soil mg/kg soil mg/kg soil mg/kg soil Soil Comments (e.g. Sample ID, Sample Depth, Sample Date, etc.) Highest Soil Concentrations Remaining at the Site Highest Air Concentrations Remaining at the Site Air Comments (e.g. Sample ID, Sample Date, etc.) Groundwater Comments (e.g. Sample ID, Sample Date, etc.)Chemical Name (CAS #) Highest Groundwater Concentrations Remaining at the Site Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used * - Site-Specific Cleanup Levels assume a Natural Attenuation Factor of 1 (i.e. no natural attenuation). c - carcinogen; nc - non-carcinogen Site-specific Parameters used in Calculations Parameter Comments Soil Receptor i Lgw Ls Pavement Precip. Soil Zone W inches/year Not applicable ft Units Not applicable Not applicable ft-vertical/ft-lateral ft Not applicable ft GP-02 @ 7-10' bg 18.6 Yes 80 Value Silty sand Commercial/ Industrial 0.004 9 8 PAVED: contamination beneath pavement Depth to groundwater Hydraulic gradient Select the most sensitive Receptor that is present at the site Soil type representative of site Description Width of contaminated source area parallel to groundwater flow or wind direction Annual precipitation Is contamination present in the saturated zone? Is contamination beneath pavement or bare soils? Depth to contaminated soil Ad d i t i o n a l C h e m i c a l s o f C o n c e r n (n o n - c a r c i n o g e n t s ) SSCL.OBL.GP-02 Page 3 of 3 1/13/2023 9:31 AM Page 1 of 3SSCL Calculator Prepared for: SSCL Calculator Prepared by: Site name: Site address: Facility ID: Release ID: Contact name: Contact phone: Contact e-mail: Site-Specific Cleanup Levels* for Commercial/ Industrial Receptors Air Groundwater Soil SSCLair SSCLwing SSCLwesp SSCLwamb SSCLs-leach SSCLsesp SSCLsamb SSCLss (See Eq. D.1) (See Eq. D.2) (See Eq. D.3)(See Eq. D.4) (See Eq. D.5) (See Eq. D.6) (See Eq. D.7) (See Eq. D.8) Air Groundwater Groundwater Groundwater Subsurface soil Subsurface soil Subsurface soil Surface Soil Inhalation Ingestion Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Leaching to groundwater (groundwater ingestion) Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Ingestion of soil, inhalation of vapors and particles, and dermal contact µg/m3 air µg/m 3 air mg/L water mg/L water mg/L water mg/L water mg/kg soil mg/kg soil mg/kg soil mg/kg soil mg/kg soil Benzene (71-43-2) c 4.93E-01 0.297 SG-1 7/28/2011 (slab atten. factor *0.03)9.87E-03 7.20E-01 1.87E+02 0.005 MW-1 5.64E-02 3.50E-03 1.31E-01 5.69E+00 0.52 B-2@ 9-10' Toluene (108-88-3) nc 7.31E+03 1.291 SG-1 7/28/2011 (slab atten. factor *0.03)8.18E+00 1.20E+04 3.15E+06 0.012 MW-1 7.52E+01 7.02E+01 2.63E+03 5.40E+03 0.88 B-2@ 9-10' Ethylbenzene (100-41-4) nc 1.48E+03 0.150 SG-1 7/28/2011 (slab atten. factor *0.03)1.02E+01 2.68E+03 7.03E+05 0.901 MW-1 1.63E+02 2.17E+01 8.10E+02 6.47E+03 2.76 B-2@ 9-10' Xylenes (1330-20-7) nc 1.48E+02 0.571 SG-1 7/28/2011 (slab atten. factor *0.03)2.04E+01 2.37E+02 6.17E+04 1.69 MW-1 3.31E+02 2.98E+00 1.11E+02 6.57E+03 2.48 B-2@ 9-10' Naphthalene (91-20-3) nc 4.39E+00 0.300 SG-1 7/28/2011 (slab atten. factor *0.03)2.04E+00 1.23E+01 2.30E+03 0.34 MW-1 4.03E+01 2.07E+00 7.74E+01 3.63E+02 3.74 B-2@ 9-10' MTBE (1634-04-04) nc 4.38E+03 0.150 SG-1 7/28/2011 (slab atten. factor *0.03)5.11E-01 2.90E+03 2.47E+05 0.005 MW-1 1.44E+00 1.59E+02 5.95E+03 3.40E+02 0.24 B-2@ 9-10' Alkyl benzenes (C9-C10) [average values]nc 3.07E+02 4.09E+00 5.76E+02 1.51E+05 22.4 MW-1 1.27E+02 9.31E+00 3.48E+02 2.47E+03 632 B-2@ 9-10' Alkyl naphthalenes (C11-C13) [average values]nc 3.07E+02 4.09E+00 8.25E+02 1.57E+05 5.6 MW-1 5.98E+02 9.97E+02 3.73E+04 1.17E+04 1820 B-2@ 9-10' Total PAHs (C12-C22) [average values]nc 1.53E+02 3.07E+00 1.39E+02 3.45E+04 5.6 MW-1 3.94E+03 3.64E+02 1.36E+04 7.15E+03 1820 B-2@ 9-10' Aliphatics (C5-C6) [Hexane (110-54-3)]nc 3.07E+02 0.270 SG-1 7/28/2011 6.13E+00 5.08E+02 1.36E+05 22.4 MW-1 1.96E+03 6.85E-01 2.56E+01 3.54E+03 632 B-2@ 9-10' Aliphatics (C7-C8) [Heptane (142-82-5)]nc 3.07E+02 0.282 SG-2 1/10/2013 (slab atten. factor *0.03)6.13E+00 6.14E+02 1.64E+05 22.4 MW-1 3.92E+03 9.33E-01 3.49E+01 3.54E+03 632 B-2@ 9-10' Aliphatics (C9-C10) [Nonane (111-84-2)]nc 1.48E+03 0.390 SG-2 1/10/2013 (slab atten. factor *0.03)1.02E+01 3.47E+03 9.27E+05 22.4 MW-1 1.87E+04 6.47E+00 2.42E+02 6.47E+03 632 B-2@ 9-10' Aliphatics (C11-C12) [Undecane (1120-21-4)]nc 1.48E+03 1.02E+01 3.94E+03 1.05E+06 5.6 MW-1 7.79E+04 3.77E+01 1.41E+03 6.47E+03 1820 B-2@ 9-10' Aliphatics (C13-C16) [Hexadecane (544-76-3)]nc 1.48E+03 1.02E+01 4.55E+03 1.22E+06 5.6 MW-1 1.05E+06 5.93E+02 2.22E+04 6.47E+03 1820 B-2@ 9-10' Aliphatics (C17-C21) [Heptadecane (629-78-7)]nc 1.02E+04 2.04E+02 3.75E+04 1.00E+07 5.6 MW-1 1.67E+09 5.66E+05 2.12E+07 1.29E+05 1820 B-2@ 9-10' Aliphatics (C22-C35) [Heptadecane (629-78-7)]nc 1.02E+04 2.04E+02 3.75E+04 1.00E+07 5.6 MW-1 1.67E+09 5.66E+05 2.12E+07 1.29E+05 1820 B-2@ 9-10' Mark Crim DEQ/ERR Date prepared:1/10/2023 Former Pyramid Oil Company at IML 3120 South Main Street, South Salt Lake, Utah 4000124 OBL Soil Comments (e.g. Sample ID, Sample Depth, Sample Date, etc.) Highest Soil Concentrations Remaining at the Site Name: Company, Agency, other: Phone: E-mail: UST Consultant Cert. #: Highest Air Concentrations Remaining at the Site Air Comments (e.g. Sample ID, Sample Date, etc.) Groundwater Comments (e.g. Sample ID, Sample Date, etc.)Chemical Name (CAS #) Pr i m a r y C h e m i c a l s o f C o n c e r n To t a l P e t r o l e u m H y d r o c a r b o n F r a c t i o n s Highest Groundwater Concentrations Remaining at the Site SSCL.OBL. B-2 and MW-01 Page 1 of 3 1/13/2023 9:49 AM Page 2 of 3Site-Specific Cleanup Levels* for Commercial/ Industrial Receptors Air Groundwater Soil SSCLair SSCLwing SSCLwesp SSCLwamb SSCLs-leach SSCLsesp SSCLsamb SSCLss (See Eq. D.1) (See Eq. D.2) (See Eq. D.3)(See Eq. D.4) (See Eq. D.5) (See Eq. D.6) (See Eq. D.7) (See Eq. D.8) Air Groundwater Groundwater Groundwater Subsurface soil Subsurface soil Subsurface soil Surface Soil Inhalation Ingestion Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Leaching to groundwater (groundwater ingestion) Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Ingestion of soil, inhalation of vapors and particles, and dermal contact µg/m3 air µg/m 3 air mg/L water mg/L water mg/L water mg/L water mg/kg soil mg/kg soil mg/kg soil mg/kg soil mg/kg soil Soil Comments (e.g. Sample ID, Sample Depth, Sample Date, etc.) Highest Soil Concentrations Remaining at the Site Highest Air Concentrations Remaining at the Site Air Comments (e.g. Sample ID, Sample Date, etc.) Groundwater Comments (e.g. Sample ID, Sample Date, etc.)Chemical Name (CAS #) Highest Groundwater Concentrations Remaining at the Site Acenaphthylene (208-96-8)nc 1.53E+02 3.07E+00 1.29E+03 1.09E+05 1.80E+02 1.48E+03 5.54E+04 7.75E+03 Acenaphthene (83-32-9)nc 8.69E+01 6.13E+00 5.68E+02 5.54E+04 3.12E+02 5.24E+02 1.96E+04 6.01E+03 Fluorene (86-73-7)nc 5.62E+01 4.09E+00 5.78E+02 4.23E+04 3.35E+02 9.81E+02 3.67E+04 5.54E+03 Phenanthrene (85-01-8)nc 1.53E+02 3.07E+00 3.75E+03 1.91E+05 5.16E+02 1.46E+04 5.45E+05 1.18E+04 Anthracene (120-12-7)nc 4.38E+02 3.07E+01 9.05E+03 4.84E+05 4.88E+03 3.28E+04 1.23E+06 6.86E+04 Fluoranthene (206-44-0)nc 5.83E+01 4.09E+00 4.62E+03 1.83E+05 2.32E+03 6.38E+04 2.39E+06 1.57E+04 Pyrene (129-00-0)nc 4.38E+01 3.07E+00 4.31E+03 1.63E+05 1.61E+03 5.55E+04 2.07E+06 1.20E+04 Benz(a)Anthracene (56-55-3)c 1.96E-01 3.92E-04 1.62E+01 6.08E+02 8.15E-01 8.24E+02 3.08E+04 2.00E+00 Chrysene (218-01-09)c 1.96E+00 3.92E-02 4.22E+02 1.51E+04 6.51E+01 1.73E+04 6.48E+05 1.94E+02 Benzo(b)Fluoranthene (205-99-2)c 1.96E-02 3.92E-04 1.06E+00 4.67E+01 6.64E-01 4.28E+01 1.60E+03 1.88E+00 Benzo(k)-Fluoranthene (207-08-09)c 1.96E-01 3.92E-03 7.02E+02 2.35E+04 9.67E+00 4.32E+04 1.62E+06 2.00E+01 Benzo(a)-Pyrene (50-32-8)c 2.35E-03 3.92E-05 2.29E+00 7.71E+01 1.05E-01 1.52E+02 5.70E+03 1.99E-01 Indeno(1, 2, 3-Cd)Pyrene (193-39- 5)c 2.35E-02 3.92E-04 1.36E+03 8.68E+03 6.48E-02 5.53E+03 3.95E+04 1.98E+00 Dibenzo-(a, h)Anthracene (53-70- 3)c 2.35E-02 3.92E-04 5.28E+01 1.77E+03 5.92E+00 1.99E+04 7.43E+05 2.00E+00 Benzo (g, h, i)-Perylene (191-24-2)nc 1.53E+02 3.07E+00 9.37E+04 3.21E+06 1.94E+04 1.48E+07 5.52E+08 1.56E+04 Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Not used c Not used Not used Not used Not used Not used Not used Not used Not used Ad d i t i o n a l C h e m i c a l s o f C o n c e r n (c a r c i n o g e n t s ) In d i v i d u a l P o l y n u c l e a r A r o m a t i c H y d r o c a r b o n s ( P A H s ) SSCL.OBL. B-2 and MW-01 Page 2 of 3 1/13/2023 9:49 AM Page 3 of 3Site-Specific Cleanup Levels* for Commercial/ Industrial Receptors Air Groundwater Soil SSCLair SSCLwing SSCLwesp SSCLwamb SSCLs-leach SSCLsesp SSCLsamb SSCLss (See Eq. D.1) (See Eq. D.2) (See Eq. D.3)(See Eq. D.4) (See Eq. D.5) (See Eq. D.6) (See Eq. D.7) (See Eq. D.8) Air Groundwater Groundwater Groundwater Subsurface soil Subsurface soil Subsurface soil Surface Soil Inhalation Ingestion Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Leaching to groundwater (groundwater ingestion) Indoor air (enclosed space) vapor inhalation Outdoor air (ambient) vapor inhalation Ingestion of soil, inhalation of vapors and particles, and dermal contact µg/m3 air µg/m 3 air mg/L water mg/L water mg/L water mg/L water mg/kg soil mg/kg soil mg/kg soil mg/kg soil mg/kg soil Soil Comments (e.g. Sample ID, Sample Depth, Sample Date, etc.) Highest Soil Concentrations Remaining at the Site Highest Air Concentrations Remaining at the Site Air Comments (e.g. Sample ID, Sample Date, etc.) Groundwater Comments (e.g. Sample ID, Sample Date, etc.)Chemical Name (CAS #) Highest Groundwater Concentrations Remaining at the Site Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used Not used nc Not used Not used Not used Not used Not used Not used Not used Not used * - Site-Specific Cleanup Levels assume a Natural Attenuation Factor of 1 (i.e. no natural attenuation). c - carcinogen; nc - non-carcinogen Site-specific Parameters used in Calculations Parameter Comments Soil Receptor i Lgw Ls Pavement Precip. Soil Zone W inches/year Not applicable ft Units Not applicable Not applicable ft-vertical/ft-lateral ft Not applicable ft B-2 @ 9-10' bg and MW-01 18.6 Yes 80 Value Silty sand Commercial/ Industrial 0.004 9 8 PAVED: contamination beneath pavement Depth to groundwater Hydraulic gradient Select the most sensitive Receptor that is present at the site Soil type representative of site Description Width of contaminated source area parallel to groundwater flow or wind direction Annual precipitation Is contamination present in the saturated zone? Is contamination beneath pavement or bare soils? Depth to contaminated soil Ad d i t i o n a l C h e m i c a l s o f C o n c e r n (n o n - c a r c i n o g e n t s ) SSCL.OBL. B-2 and MW-01 Page 3 of 3 1/13/2023 9:49 AM Attachment C Utility Map Legend: Natural Gas Sanitary Sewer Storm Sewer Drinking Water Electric