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Home My WebLink AboutDERR-2024-004799Antea USA, Inc. 2150 South 1300 East, Suite 500 Salt Lake City, Utah 84106 USA www.anteagroup.com March 1, 2024 Ms. Nicole Chavez State of Utah Division of Environmental Response and Remediation 195 North 1950 West Salt Lake City, Utah 84116-4840 Subject: High Vacuum Dual Phase Extraction Work Plan and Budget Work Plan/Cost Estimate #006 Hart’s Gas and Food, LLC 335 West 7200 South, Midvale, UT LUST ID NBF / Facility ID #1000247 Dear Ms. Chavez: Antea™Group is presenting this work plan to conduct a high vacuum dual phase extraction (HVDPE) event on the existing monitoring well (MWH-2) on behalf of Hart’s Gas and Food, LLC, at the above-referenced facility. This work plan was prepared in response to the additional work requested by the Utah Division of Environmental Response and Remediation (DERR) in the letter Request for Work Plan and Budget for Groundwater Sampling and Soil Extraction Petroleum Storage Tank Fund dated October 30, 2023. This work plan is being submitted to the DERR for approval. Site History The site has been reported to have been occupied by a retail gasoline service station that originally utilized three steel Underground Storage Tanks (USTs) since 1971. The steel USTs were closed and removed from the site in October 1998. During closure activities, contaminated soil was discovered in the UST basin area. A release was reported to the DERR on October 26, 1998, and was assigned release ID # KRP. Impacted soil was over-excavated and hauled off-site. Release KRP was issued a No Further Action (NFA) letter in September 1999. In December 1998, four fiberglass-reinforced plastic USTs were installed within the original tank basin. No known releases have occurred from the current UST system. In January 2000, a release was discovered at the Chevron gasoline station located to the west across Cottonwood Street. Numerous subsurface investigations and groundwater monitoring events have occurred at the Chevron facility to define and evaluate the magnitude and extent of the release. To help delineate the Chevron facility’s release, three sets of nested monitoring wells (MW-14/MW-14A, MW-15/MW-15A, MW- 16/MW-16A) were installed on Midvale City Right-of-Way (sidewalk), located within proximity to the Hart’s western property boundary. Nested monitoring wells MW-14/MW-14A, MW-15/MW-15A, and MW-16/MW-16A have historically provided intermittent groundwater for the collection of water samples and laboratory analysis. Ms. Nicole Chavez State of Utah Closure Evaluation Work Plan/Cost Estimate #006 Hart’s Gas and Food 2 When groundwater has been present, analytical results have indicated contaminants of concern (CoCs) in samples collected from MW-14 exceeding DERR ISLs and water collected from MW-14A containing CoCs exceeding Tier 1 screening levels. In October 2016, the DERR directed a State contracted consultant to perform a subsurface investigation on the Hart’s property to evaluate on-site conditions for a potential source of the identified CoCs in MW-14 and MW- 14A. The subsurface investigation included five soil borings using direct push technology. All borings were completed with monitoring wells (MWH-1 through MWH-5). Due to insufficient groundwater volumes in MWH-1 through MWH-4, groundwater samples were only collected from MWH-5. The report concluded that no specific source was identified, however, on-site soil impacts were detected above Tier 1 Screening Levels in the MWH-3 boring at a depth of 22 feet. Results from the subsurface Investigation can be found in the Subsurface Investigation Report submitted on January 20, 2017, by ATC Group Services. On June 18, 2018, the most recent groundwater monitoring event was performed by Underwood Environmental. The monitoring event included gauging 2 wells on the Chevron site (MW-1, MW-7) 1 well in the 7200 South right-of-way (MW-6), 8 wells in the Cottonwood Street right-of-way (MW-8, MW-14, MW-14A, MW- 15, MW-15A, MW-16, MW-16A, MW-19) and 4 wells on the Harts site (MWH-1, MWH-2, MWH-3, and MWH-4). Additionally, well MWH-5 located across 7200 South to the northwest was gauged. Of the 16 wells gauged, only wells (MW-6, MW-7, MW-14, MWH-2, and MWH-5) contained sufficient water to collect samples. Laboratory results indicated that monitoring wells MW-14 and MWH-2 exceeded the Initial Screening Levels (ISLs) for one or more hydrocarbon constituents. MW-14 detected benzene at 0.008 mg/L and MWH-2 detected benzene at 0.018 mg/L, TPH-GRO at 1.48 mg/L, and TPH-DRO at 2.5 mg/L. The groundwater flow direction was determined to be towards the south-southeast. On October 12 and 13, 2020, five soil borings (SB-1 through SB-5) were advanced on the Hart’s Gas and Food property. Soil samples were collected continuously beginning at five feet and were screened for volatile organic compounds using a Photoionization Detector (PID). Three soil samples were collected for laboratory analysis from each soil boring from the zones of highest PID readings or at the bottom of the boring. Soil screening results indicated elevated PID readings at depths greater than 20 feet in soil borings SB-1, SB-2, SB-3, and SB-4 with the highest PID readings generally observed in the silty sand layers at depths between 20 to 40 feet below ground surface (bgs). The PID readings were observed to decrease at depths greater than 40 feet in the four soil borings and no significant PID readings were observed in soil boring SB-5. Soil analytical results indicate COCs were detected above ISLs and Tier 1 Screening Criteria in soil samples collected from soil borings SB-1, SB-2, SB- 3, and SB-4. No COCs were detected above ISLs in soil samples collected from soil boring SB-5. On October 14, 2020 Monitoring wells (MWH-1 through MWH-5) were gauged and sampled, with MWH-3 and MWH-4 being gauged as dry and were not sampled. MWH-2 exceeded Tier 1 Screening Criteria for TPH-DRO at 16.5 mg/L. MWH-2 exceeded ISLs for Benzene at 0.100 mg/L and TPH-GRO at 3.04 mg/L. Groundwater analytical results did not detect COCs above ISLs in MWH-1 and MWH-5. On June 16, 2021, groundwater monitoring of wells MWH-1 through MWH-5 were gauged and sampled. Monitoring wells MWH-3 and MWH-4 were gauged as dry and could not be sampled. The observed intermittent occurrence of groundwater in the on-site wells indicated the saturated zones observed in MWH-1 and MWH-2 were not continuous, and a groundwater flow direction across the well network could not be determined. In MWH-2, 0.17 feet of Light Non-Aqueous Phase Liquid (LNAPL) was observed. In MWH-1 and MWH-5 no COCs Ms. Nicole Chavez State of Utah Closure Evaluation Work Plan/Cost Estimate #006 Hart’s Gas and Food 3 were detected above ISLs. Benzene exceeded Tier 1 Screening Criteria in MWH-2 at a concentration of 0.455 mg/L. TPH-GRO exceeded ISLs at MWH-2 at a concentration of 3.36 mg/L. On December 14th, 2021, groundwater monitoring of wells MWH-1 through MWH-5 were gauged and sampled. Monitoring wells MWH-3 and MWH-4 were gauged as dry and could not be sampled. In MWH-1 and MWH-5 no COCs were detected above ISLs. MWH-2 exceeded ISLs for Benzene (0.092 mg/L), TPH-GRO (2.03 mg/L), and TPH-DRO (7.45 mg/L). No COCs in MWH-2 exceeded Tier 1 Screening Criteria. On November 3, 2022, Antea Group submitted a Closure Evaluation Report to the UDEQ, outlining the nature and extent of the known on-site contamination. The report indicated that potential sources of the contamination included residual impacts from the historical on-site Release ID #KRD, release from the current UST system, plume migration from the adjoining Chevron Release ID #LCS, and/or unknown on/off-site orphan USTs. Additionally, the report indicated that the groundwater ingestion and exposure pathway, and the vapor intrusion to indoor and outdoor pathways are all closed and the risks to public health have been fully investigated. Antea Group evaluated the effectiveness and feasibility of multiple remediation technologies and determined that Dual-Phase Vacuum Extraction (DPVE) would be the most appropriate for this site. This recommendation was reached because of DPVE’s ability to address larger areas of the saturated zone at a low cost compared to that of other remediation technologies. Due to the current land usage, lack of open exposure pathways, minimal risks to receptors and public health, and the potential for residual impacts and source areas located off site and/or within public right of ways, Antea Group suggested that achieving cleanup standards was not a feasible objective and recommended the site be considered for conditional NFA. In a letter dated October 30, 2023, UDEQ responded to the Closure Evaluation Report with a request for a five- day HVDPE event to address residual on-site contamination. Proposed Scope The proposed scope of work has been developed to conduct a HVDPE event for five days to remediate residual on-site impacted soil and groundwater at the Midvale Harts Facility. Two groundwater monitoring events will also be conducted, one prior to the HVDPE event and another following the event, with the goal of determining the effectiveness of the remediation activities. Due to the lack of subcontractors capable of implementing this plan, UDEQ has requested that we use CalClean Inc. to facilitate the HDVPE event. The following scope of work is proposed to address the residual contamination and evaluate the site conditions before and after remediation activities: HDVPE Event  CalClean Inc. will be contracted to conduct a five-day continuous HVDPE event at MWH-2 utilizing their proprietary technology and equipment. o During this event, fluid and vapors will be removed from MWH-2 for five consecutive days. Two hours of downtime per day is expected for maintenance and repairs of equipment, and any downtime in excess of two hours will be made up at end of event. o Vapors will pass through a filtration system prior to release and ports are available for effluent testing. o Groundwater will be filtered and treated, then either captured for disposal, or released into the sanitary sewer. Ports for effluent sampling are available at multiple points throughout the treatment process. Ms. Nicole Chavez State of Utah Closure Evaluation Work Plan/Cost Estimate #006 Hart’s Gas and Food 4 Groundwater sampling Event  Groundwater sampling will be conducted before and after the HVDPE event.  Well MWH-2 will be gauged prior to sampling.  Groundwater samples will be collected and submitted to Pace National of Mount Juliet, Tennessee to be analyzed for BTEXN, MTBE, TPH-GRO, and TPH-DRO using EPA Methods 8015 and 8260B. Data Review and Report Preparation  A groundwater monitoring report presenting the groundwater monitoring results will be prepared containing an introduction, site description, summary of monitoring results, sampling and HVDPE methodology, and conclusions.  Data will be summarized on tables and appropriate maps will be presented.  The report will be submitted to Hart’s Gas and Food, LLC and the DERR. Reimbursement Claim Preparation Preparation of reimbursement claim following the completion of this work plan. Costs The work plan cost estimate is attached as Table 1. The costs are in accordance with Antea Group’s contractual agreement with Hart’s Gas and Food, LLC and UDEQ Cost Guidelines. If you have any questions or comments, please contact Marissa Hartley at (916) 996-3750 or Stuart Beling at (435) 655-0570. Sincerely, Marissa Hartley Project Manager, PG Antea Group Reviewed by: Stuart Beling Senior Project Manager PG CC # 65 Antea Group Attachments - Table 1 – Cost Estimate cc: Mr. Sadiq Mohammed – Parkland Fuel Corp (Electronic Copy) Work Plan/Cost Estimate #6 Description Amount Units Rate Cost Project Management and Coordination Senior Project Manager (P101) - Project Management/DERR Meeting and Correspondence/Financial Management 6 hrs $152.00 $912.00 Project Manager (P103) - Correspondence/Financial management/Subcontractor Contracting 12 hrs $118.00 $1,416.00 Subtotal $2,328.00 Work Plan & Budget Preparation Based on DERR's experience and guidelines, cost for preparing this WP&B shall not exceed $725.00 Lump sum $725.00 $725.00 Subtotal $725.00 HVDPE Event and Groundwater Sampling Senior Project Manager (P101) - Project Management/DERR Meeting and Correspondence/Technical Support 1 hrs $152.00 $152.00 Project Manager (P103) - Correspondence/Financial management/Field Staff Support/Permitting 5 hrs $118.00 $590.00 Field Scientist (P104) - Groundwater Sampling/HVDPE Oversight 60 hrs $101.00 $6,060.00 Subtotal $6,802.00 Equipment/Materials/Mileage Mileage (50 mile roundtrip @ $0.66/mile)7 roundtrips $33.00 $231.00 Disposable Bailers 2 Each $15.00 $30.00 Water Level Indicator 2 Day $30.00 $60.00 Sampling Supplies / Disposables 2 Day $5.00 $10.00 PID 5 Day $85.00 $425.00 Subtotal $756.00 Laboratory TPH-DRO (method 8015) - Water 2 Each $51.00 $102.00 BTEXMN and TPH-GRO (method 8260)- Water 2 Each $112.00 $224.00 Disposal and energy/environmental fee 1 Each $37.00 $37.00 Subtotal $363.00 Subcontractor Costs CalClean Inc. HVDPE five-day event Lump sum $28,957.00 Report Preparation Senior Project Manager (P101) - Data Evaluation and Report Review 1 hrs $152.00 $152.00 Project Manager (P103) - Data Collection, Evaluation, and Reporting 8 hrs $118.00 $944.00 Field Scientists (P104) - Report Draft 10 hrs $101.00 $1,010.00 Drafter (P107) - Figures 2 hrs $85.00 $170.00 Administrative Assistant (P109) - Admin Support 1 hrs $62.00 $62.00 Subtotal $1,096.00 Final Reimbursement Claim Preparation Project Manager (P103) - Voucher Review and Submittal 1 hrs $118.00 $118.00 PST Fund Claims Specialist (P109) - Voucher Preparation 3.5 hrs $78.00 $273.00 Subtotal $391.00 Project Total = $41,418.00 Table 1 Hart's Gas and Food, LLC Facility ID #4000408 335 West 7200 South Midvale, Utah