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HomeMy WebLinkAboutDERR-2024-008604195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144840 • Salt Lake City, UT 84114-4840 Telephone (801) 536-4100 • Fax (801) 359-8853 • T.D.D. (801) 536-4284 www.deq.utah.gov Printed on 100% recycled paper State of Utah SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor Department of Environmental Quality Kimberly D. Shelley Executive Director DIVISION OF ENVIRONMENTAL RESPONSE AND REMEDIATION Brent H. Everett Director ERRC-093-24 June 27, 2024 Ryan Dunham Site Assessment Manager U.S. EPA, Region 8 (8EPR-B) 1595 Wynkoop Street Denver, Colorado 80202-1129 Dear Mr. Dunham: Enclosed for your review is an Expanded Site Inspection 2 Work Plan for the Maple Street Plume (SEMS EPA ID UTN000820949) (herein referred to as “Site”) located in Midvale, Salt Lake County, Utah. This investigation was initiated because a chlorinated solvent, tetrachloroethene (PCE), was detected during routine water quality monitoring of a municipal well in 2010. A 2020 Site Investigation detected PCE, trichloroethene (TCE), and benzene in soil gas samples exceeding at least one U.S. Environmental Protection Agency (EPA) benchmark at several former dry cleaner locations in the area. A following 2022 Expanded Site Investigation (ESI) detected PCE and TCE at levels exceeding at least one EPA benchmark at only one of the dry cleaners. Though it successfully narrowed the search area, the ESI was unable to assess the extent of the plume and the risk subsurface vapor intrusion poses to nearby residents. The Division of Environmental Response and Remediation recommends collecting additional soil and soil gas samples to fill in data gaps and develop strategies to safeguard human health and environment. If you have any questions, please contact me at (385) 391-8147, or via email at etagliaferri@utah.gov. Sincerely, Edoardo Tagliaferri, Site Assessment Project Manager Division of Environmental Response and Remediation Page 2 ET/tt Enclosure: Maple Street Plume ESI 2 Work Plan cc: Dorothy Adams, Executive Director, Salt Lake County Health Department Ron Lund, Environmental Health Director, Salt Lake County Health Department EXPANDED SITE INSPECTION WORK PLAN Maple Street Plume Salt Lake County, Utah UTN000820949 May 2024 EXPANDED SITE INSPECTION WORK PLAN Maple Street Plume Salt Lake County, Utah UTN000820949 Utah Department of Environmental Quality Division of Environmental Response and Remediation Prepared by: Edoardo Tagliaferri Approved: _______________________________________ Date: _________ Edoardo Tagliaferri, Project Manager Approved: _______________________________________ Date: _________ Thomas Daniels, Site Assessment Section Manager Approved: _______________________________________ Date: _________ Ryan Dunham, Site Assessment Manager, EPA Region 8 Expanded Site Inspection Work Plan 1 Maple Street Plume – UTN000820949 Table of Contents 1.0 INTRODUCTION 1 2.0 OBJECTIVES 1 3.0 BACKGROUND INFORMATION 2 3.1 Site Location and Description 2 3.2 Site History 2 3.3 Previous Investigations 2 3.4 Physical Conditions 3 3.4.1 Hydrogeology 3 3.4.2 Hydrology 4 3.4.3 Geology 5 3.4.4 Meteorology 5 4.0 PRELIMINARY PATHWAY ANALYSIS 5 4.1 Waste/Source Characteristics 5 4.2 Groundwater Pathway Analysis 6 4.3 Soil and Subsurface Vapor Intrusion Pathway Analysis 6 4.3.1 Data Gaps 7 4.4 Surface Water Pathway Analysis 7 4.5 Air Pathway 7 5.0 FIELD PROCEDURES 7 5.1 Concept of Operations 7 5.1.1 Schedule of Work 8 5.1.2 Safety 8 5.1.3 Site Access and Logistics 8 5.2 Sampling Locations 8 5.2.1 Subsurface Soil, Groundwater, Soil Gas, and Indoor Air Samples 9 5.3 Sampling Methods 9 5.3.1 Soil Gas Sampling 9 5.3.2 Subsurface Soil Sampling 9 5.4 Investigation Derived Waste 10 5.5 Analytical Parameters 10 6.0 QUALITY CONTROL PROCEDURES 10 7.0 CHAIN-OF-CUSTODY 10 Expanded Site Inspection Work Plan 2 Maple Street Plume – UTN000820949 8.0 DATA REDUCTION, VALIDATION, AND REPORTING 10 9.0 REFERENCES 11 Expanded Site Inspection Work Plan 3 Maple Street Plume – UTN000820949 LIST OF FIGURES Figure 1 Site Location Figure 2 2020 SI Sample Locations and Selected Results Figure 3 Previous ESI 2023 Sample Locations and Selected Results Figure 4 Proposed Sampling Locations Figure 5 Proposed Sampling Locations. LIST OF TABLES: Table 1 Data Quality Objectives Table 2 Sample Locations, Descriptions, and Rationale Table 3 Sample Analysis Checklist LIST OF APPENDICES Appendix A Site Health and Safety Plan Appendix B Consent for Access to Property Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 1 1.0 INTRODUCTION Under the authority of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980, the Superfund Amendments and Reauthorization Act (SARA) of 1986, and in accordance with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), the Utah Department of Environmental Quality (UDEQ) Division of Environmental Response and Remediation (DERR) has prepared this Site Inspection Work Plan (Work Plan) as part of the Expanded Site Inspection (ESI) of the Maple Street Plume, UTN000820949, (referred to as the “Site”) in Midvale, Salt Lake County, Utah. This ESI will be conducted under a cooperative agreement between the DERR and the United States Environmental Protection Agency (EPA), Region 8. This investigation was initiated because a chlorinated solvent, tetrachloroethene (PCE), was detected during routine water quality monitoring of a municipal well in 2010. A 2020 Site Investigation (SI) detected PCE, trichloroethene (TCE), and benzene in soil gas samples at concentrations exceeding at least one EPA benchmark (Frier 2020). A following 2022 Expanded Site Investigation (ESI) used soil and soil gas sampling; at the former Fashion Cleaners property (now Quik Pik Market, and henceforth referred to as such) soil gas sampling detected levels of PCE and TCE well above residential Vapor Intrusion Screening Levels (VISLs); other than at that location, chlorinated solvents were either not detected, or were detected below relevant VISLs. Additional sampling was recommended to determine the extent of chlorinated solvent contamination in the subsurface and assess the risk of subsurface vapor intrusion to a nearby residential area. This ESI Work Plan 2 describes sampling procedures that will be used to delineate the plume from the suspected contaminant source area and assess potential impacts on the surrounding community 2.0 OBJECTIVES The findings outlined in the subsequent report will provide information to help support decisions regarding the need for further action at the Site. The specific objectives of this ESI 2 are to: Delineate the plume from the suspected contaminant source area: Collect additional Site information, including sampling data necessary to fill observed data gaps; Identify levels of volatile organic compounds (VOCs) in soils and soil gas at residences and businesses near the potential source area; Identify potential targets that may be affected by Site contamination or by the migration of contaminants via the suspected exposure pathways; Determine if continued assessment work under CERCLA or other authority is warranted. Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 2 3.0 BACKGROUND INFORMATION Information pertaining to the history and current status of the Site was obtained from the Preliminary Assessment Worksheet (Taylor 2019a), the Site Investigation Work Plan (Taylor 2019b), the Site Investigation Analytical Results Report for the Maple Street Plume (Frier 2020), and the Expanded Site Investigation Analytical Results Report for the Maple Street Plume (Sandlin 2023). 3.1 Site Location and Description The Maple Street Plume Site is located in Midvale, Salt Lake County, Utah (Figure 1). The municipal well where contaminants were first identified is located at 7610 South Maple Street, immediately east of a Utah Transit Authority Rail Line and south of a residential cul-de-sac at the end of Blisswood Drive. Access to the municipal well site is provided along an abandoned roadway (Park Street) where it intersects Maple Street directly south of a churchyard. The two wells at that location are referred to as the Park Street (Cold) Well and Park Street (Warm) Well. The surrounding area contains mixed residential and commercial real estate, including five historical laundry or dry cleaning facilities (Figure 2). Such facilities are significant because they regularly utilize chlorinated solvents, making them potential sources of contaminants. 3.2 Site History Contamination was first recognized at the Site in 2010 when routine groundwater sampling from the Park Street (Cold) Well identified PCE at a concentration of 1.7 µg/L. PCE was not detected in groundwater samples collected from the Park Street (Warm) Well. In 2013, both wells were abandoned due to average uranium concentrations [43 µg/L] exceeding the drinking water Maximum Contaminant Level (MCL) of 30 µg/L (Utah Division of Drinking Water 2021; Hoyle 2018). The uranium is unrelated to the Site and the PCE observed warranted further investigation. PCE is not naturally occurring and is most often introduced to the environment through its use as a solvent in i cleaning. Water quality testing continued to identify trace amounts of PCE until the well was abandoned in 2013, but at concentrations below the MCL of 5 µg/L for PCE. These limited data are the only direct record of groundwater contamination at the Site. Further groundwater testing of these wells is no longer possible as they are no longer in operation (Utah Division of Drinking Water 2021). 3.3 Previous Investigations A Preliminary Assessment (PA) completed in January 2019 identified two laundry and/or dry cleaning facilities as potential contaminant sources that may have used chlorinated solvents during daily operations (Taylor 2019a): Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 3 Day-Nite Laundercenter may have operated at what is now 7669 South Maple Street (Salt Lake County Auditor 1998). White Raven Tattoo now operates at this location. Fashion Cleaners (now Quik Pik market) began operations in 2009 at 118 West Center Street and was active until at least January 2023; Quik Pik Market now operates at the location as a convenience store. A Site Investigation (SI) completed in May 2020 identified two additional dry cleaning facilities as potential contaminant sources (Figure 2) (Frier 2020): Matt’s Cleaners operated at 7565 South State Street in the 1960s. Just A Car Lot, a used car sales business, now operates at this location. Norge Dry Cleaning Village operated at 7615 South State Street during the 1960s. J and J Tires now operates at this location. An Expanded Site Investigation (ESI) completed in January 2023 identified the Quik Pik Market location as the only potential contaminant source after sampling it and the three other potential sources in the area (Figure 3) (Sandlin 2023). Groundwater was not sampled during the ESI because the direct push technology (DPT) probe did not reach groundwater within 20 feet of the ground surface. A natural aquiclude in the form of a thick clay formation was observed to be present above the aquifer in the Site area. In order to prevent potential contamination mobilization between aquifers, the DPT probe was not advanced further than the thick clay formation at each sample location. The risk of exposure to contaminants via the groundwater pathway is low because there are no active, downgradient municipal drinking wells within four miles of the site. Soil gas sample analysis showed that PCE and TCE are present at the Quik Pik Market location at concentrations above background and relevant EPA benchmarks (Figure 3). These contaminants were not detected at Just a Car Lot (formerly Matt’s Cleaners), J and J Tire (formerly Norge Laundry), nor the former Harv’s Cleaners; these locations are not part of this Work Plan. The ESI recommended additional soil gas and indoor air sampling to accurately assess the risk of exposure to subsurface vapors at residences and businesses proximal to the Quik Pik Market location (Sandlin 2023). 3.4 Physical Conditions 3.4.1 Hydrogeology The Park Street wells and the rest of the Site are located among alluvial basin sediments of the Salt Lake Valley, which consist of unconsolidated to semi-consolidated deposits of Tertiary to Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 4 Quaternary age (Thiros 2010). The groundwater system in these valley deposits includes both a shallow and deep aquifer, separated by discontinuous layers of fine-grained sediments. The deeper aquifer is generally unconfined in proximity to the mountains and becomes confined by these fine-grained deposits closer to the valley center. Groundwater generally moves laterally from the unconfined portion of the deep aquifer near the mountains to the confined zone near the valley center, where the Jordan River is located. Groundwater also moves from the overlying shallow aquifer to the deeper basin-fill aquifer in areas where the hydraulic gradient is downward and the confining layers are discontinuous or absent. Towards the center of the valley, there is often an upward hydraulic gradient that moves water from the deeper aquifer to the shallower one. The boundary between these dynamics and the distinction between the two aquifers is unclear or understood only in general terms in many parts of the valley. The Park Street (Cold) Well was drilled in 1961 for Midvale City Public Utilities. It is a 16-inch diameter well that produced a flow of 6.67 cubic feet per second (cfs) before it was sealed in 2013. The well is 475 feet feet bgs—meaning that the well drew a portion of its water from the shallowest aquifer (Utah Division of Drinking Water 2021). The Park Street (Warm) Well is immediately adjacent to the Park Street (Cold) Well and also has a diameter of 16 inches. It was drilled in 1966 and, before being sealed in 2013, produced a flow of 0.61 cfs. This well was drilled to a depth of 782 feet and only produced water from depths below the confining layer (Hoyle 2018; Utah Division of Drinking Water 2021). Existing well data 2018; Utah Division of Drinking Water 2021; Magna Water District 2013). A natural aquiclude in the form of a thick clay formation was observed to be present above the aquifer in the Site area (Sandlin 2023). Soil borings advanced during the ESI did not encounter groundwater at 20 feet. Likewise, soil borings advanced during the SI did not encounter groundwater at 25 feet bgs (Frier 2020). Groundwater is presumed to follow local topography, flowing to the northwest across the Site toward the Jordan River. 3.4.2 Hydrology The Site lies in the relatively flat valley bottom of the Salt Lake Valley at an elevation of approximately 4,380 feet (Davis 2000). The Jordan River and its tributaries form the main drainage for the valley and discharges into the Great Salt Lake to the north. The Site is located within relative proximity of the Jordan River, but it is not located in any recognized flood-prone area. Surface water at the Site is routed by storm drains 1.5 miles westward toward the river, which then flows 24 miles to the north and drains into the Great Salt Lake. Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 5 3.4.3 Geology The Site is located west of the Wasatch Range near the center of the Salt Lake Valley and overlies various Quaternary lacustrine deposits, including Bonneville Lake Cycle Deposits of the late Pleistocene (Davis 2000). At the Site, these deposits include calcareous laminated silts, pebbles, cobbles, and minor lenses of sands and gravels. The thickness of this unit is quite -Lake Bonneville deposits of clays, silts, sands, and gravels of mixed fluvial and lacustrine origin. These older e underlain by various Tertiary age sedimentary and volcanic rocks of the Salt Lake Formation. 3.4.4 Meteorology The Salt Lake Valley experiences meteorological phenomena heavily controlled by its physiographic position—surrounded almost entirely by mountains. It has a semi-arid environment with summer temperatures above 100 ºF and limited precipitation. July average maximum and minimum temperatures near the Site are 92.8 ºF and 58.5 ºF. January average maximum and minimum temperatures near the Site are 38.3 ºF and 17.3 ºF. The valley receives approximately 14.73 inches of average annual precipitation (Western Regional Climate Center n.d.). The region is known for poor air quality, especially in winter, because stagnant aerosol- laden air tends to rest over the valley. 4.0 PRELIMINARY PATHWAY ANALYSIS 4.1 Waste/Source Characteristics VOCs, including PCE, TCE, and benzene are the primary contaminants of concern at the Site. PCE and TCE were measured above Regional Screening Level (RSL) & Vapor Intrusion Screening Level (VISL) benchmarks in soil gas samples collected downgradient of the Quik Pik Market location [PCE = 5400 µg/m3; TCE = 53 µg/m3] during the 2023 ESI. All other laundry/dry cleaning facilities have been sampled and returned results well below RSLs for PCE and TCE. TCE is a partial degradation product of PCE that is produced as PCE biodegrades in the subsurface under anaerobic conditions (Minnesota Pollution Control Agency 2006; Watts 2006). Physiologically, both chemicals are nervous system depressants and known carcinogens. These chlorinated solvents are highly volatile, producing hazardous vapors that can migrate upwards from groundwater and soil into houses and businesses. The inhalation of vaporous PCE and/or TCE can result in dizziness, nausea, unconsciousness, and death. Prolonged exposure to these chemicals can have severe effects on the nervous system, kidney function, organ development, and the reproductive system (Centers for Disease Control 2021a; 2021b). Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 6 PCE and TCE are denser and less viscous than water (Schwille 1988), allowing them to sink in groundwater and flow through rock or sediments that would normally impede fluid flow. As such, these chemicals can cross aquifer boundaries and contaminate groundwater across confining aquifer layers. Furthermore, their insolubility in water makes PCE and TCE very difficult to remove from the groundwater system (Pankow and Cherry 1996). Benzene was detected at low levels [2 µg/m3 to 11 µg/m3] in soil gas from all sample locations, including background, below the Residential Vapor Intrusion Screening Level (VISL) benchmark [12.0 µg/m3]. Benzene is a natural part of crude oil, gasoline, cigarette smoke, and car exhaust and is widely used to make plastics, resins, nylon, lubricants, rubbers, dyes, and detergents (Centers for Disease Control 2018). Inhalation of benzene vapors can result in dizziness, drowsiness, a decrease in red blood cells, damage to the immune system, and death at high doses. 4.2 Groundwater Pathway Analysis The deeper aquifer is the primary water supply for the Salt Lake metropolitan area (Hely et al. 1971); however, it has not been accessed at the Site since 2013 when the Park Street wells were permanently sealed (Hoyle 2018). Fifty-six wells owned and operated by eight public entities are located within four miles of the Site. There are no active downgradient wells within four miles. The nearest active well, oblique to the groundwater gradient, is the Murray City 7th West #7 Well, located approximately two miles northwest of the Site and with an intake depth of 370 feet bgs (Figure 1). No chlorinated solvents have been detected in that well. There are 5,087 Points of Diversion (PODs) within a four-mile radius of the Site (Utah Division of Water Rights 2020); however, it is doubtful that the PODs are currently used for drinking water, as municipal water is readily available. For these reasons, exposure to contaminants directly through the groundwater pathway is unlikely. The primary concern is that contaminants in shallow groundwater may volatilize and expose targets via subsurface vapor intrusion. No groundwater samples are included in this Work Plan. 4.3 Soil and Subsurface Vapor Intrusion Pathway Analysis The municipal well where PCE was first identified is located within a few yards of residential areas (Figure 2), including backyards and family gathering spaces. Approximately 14,354 people live within one mile of the Site (U.S. Census Bureau 2010). It is possible that contaminants could be present within on-site soils at hazardous levels, especially near suspected source areas; however, chlorinated solvents were not detected in soils during the ESI, except at the sample location downgradient of the Quik Pik Market location, [PCE 15 µg/kg] well below RSLs [24,000 µg/kg]. It is likely that potential areas of concern are beneath pavement or asphalt, which would partition contaminants away from potential exposure to humans. The potential for exposure through soil ingestions or direct dermal contact is presumed to be low. Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 7 Soil gas samples collected during the ESI indicate that PCE, TCE, and benzene are present at the Quik Pik Market location above SCDM benchmark values. The Station at Midvale Apartments is immediately downgradient of Quik Pik Market and the sample point there, with approximately 30 homes further downgradient of the Apartments. Additional near-slab soil gas sampling is needed at homes and businesses located near the potential source area, Quik Pik Market, in order to assess the risk of subsurface vapor intrusion. 4.3.1 Data Gaps The risk of vapor intrusion into homes and businesses proximal to the site remains unknown. Further soil and soil gas sampling are needed to determine potential source areas and the risk of subsurface vapor intrusion at nearby residences and workplaces. 4.4 Surface Water Pathway Analysis Surface water runoff flows into nearby storm drains at the Site. Drainage flows west 1.5 miles to the Jordan River, which discharges to the Great Salt Lake 24 miles to the north. The potential for exposure via the surface water pathway is minimal. No surface water samples were collected during the ESI, and no surface water samples are included in this Work Plan. 4.5 Air Pathway Volatile compounds, including chlorinated solvents, have the potential to volatilize and adversely affect human health. Residences are located near the Site, including eight homes within 800 feet of the Park Street well, and a large apartment complex adjacent to Quik Pik Market (Figure 2). Approximately 413,049 people live within four miles of the Site (U.S. Census Bureau 2010). The soil gas concentrations detected from ESI samples are insufficient to affect people through general air exposure, except through intrusion directly into the confined space of buildings (section 4.3). No obvious airborne release of on-site waste is known to exist and outdoor air samples were not collected as part of the ESI because exposure through the air pathway is unlikely. No outdoor air samples are included in this Work Plan. 5.0 FIELD PROCEDURES 5.1 Concept of Operations Site sampling activities will comply with the Data Quality Objectives (Table 1) as described in the DERR Quality Assurance Project Plan (QAPP) (Palmer et al. 2020) and environmental sampling collection procedures as outlined in the EPA’s Contract Laboratory Program Guidance for Field Samplers (U.S. EPA 2014). A Conceptual Site Model (Figure 4) has been completed to evaluate the potential pathways for contaminant migrations and to assist in the selection of appropriate sampling locations. The scope of the investigation includes the advancement of nine direct-push borings at eight locations for the collection of nine soil gas Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 8 samples and nine subsurface soil samples—including field duplicates for each matrix, and a soil sample volume for MS/MSD. Any changes to proposed locations (due to access issues, etc.) will be documented in the field notes and noted in the analytical results report. Opportunity samples may be taken if warranted. 5.1.1 Schedule of Work Sampling is tentatively scheduled to begin in Spring of 2024 and is expected to take four days to complete. The scheduling of sampling activities will be finalized upon EPA’s approval of this Work Plan. Initial reconnaissance of the Site will be conducted prior to the first day of the sampling event during which alternate sample locations will be determined, if necessary, and opportunity sample locations will be identified. A 21-day turnaround for the sample analyses will be requested for the EPA Contract Laboratory Program (CLP) analytical services. 5.1.2 Safety Sampling personnel will be careful to avoid direct contact, dermal contact, inhalation, or ingestion of on-site materials. Proper safety protection will be worn at all times during sampling. Sampling will be conducted in Level D protective clothing. A photoionization detector (PID) will be used to scan soil at each of the borings, and additional safety procedures will be taken if levels exceed outdoor ambient safety levels. A Site Health and Safety Plan (HASP) has been prepared by the Project Manager and will be reviewed by all team members prior to going on-site. The HASP form is included in Appendix A. All on-site personnel will meet the Occupational Safety Health Administration (OSHA) training requirements and be qualified to work at uncontrolled hazardous waste sites. 5.1.3 Site Access and Logistics Site access and logistical functions will be arranged by the Project Manager in advance of sampling. Provisions for Site access will be arranged and the landowners will be asked to sign a DERR Consent for Access to Property form (Appendix B). Landowners will be notified of their right to obtain split-samples if requested. Coordination with the EPA contract laboratory and the local health department will be arranged prior to Site activities. The Project Manager or EPA Superfund Technical Assessment and Response Team (START) contractors will arrange sampling equipment and supplies. 5.2 Sampling Locations A biased sampling approach using analytical data from previous reports was used to identify sample locations for this ESI Work Plan, which are shown in Figure 5. A description of the planned sampling activity for the Site is included in the Tables section of this Work Plan. The following is a summary of the information presented in these tables: Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 9 Table 1 lists data quality objectives Table 2 lists sample locations, descriptions, and rationale Table 3 is a sample analysis checklist that indicates the laboratory parameters for the analyses of each sample 5.2.1 Subsurface Soil and Soil Gas Samples Soil gas and subsurface soil will be collected from borings at 12 locations at the Site (Figure 5; Table 2). Ten of these locations are situated down-gradient from Quik Pik Market. Of those ten, one is in the parking lot directly north of Quik Pik Market; four are in the street directly adjacent to Quik Pik Market; two are west in the Station at Midvale parking lot area, and the remaining three are the next block west on a residential street. One of these locations is directly south of Quik Pik Market parking area. Background soil gas and subsurface soil samples will be collected from a boring located upgradient of potential source areas to establish ambient soil gas and soil conditions and to evaluate potential observed releases for the Site. One sample for each matrix will be collected as field duplicates, and a soil sample volume will be collected for MS/MSD purposes. 5.3 Sampling Methods 5.3.1 Soil Gas Sampling Prior to advancing soil borings, Blue Stakes of Utah will be called to locate subsurface utility lines. Soil gas and soil samples will be collected from the same boring; refer to 5.3.2 for more specifics on the method for boring. The direct push rig or a hand auger will advance to approximately five feet bgs at a predetermined location. Following extraction, the Polyethylene or Tygon tubing will be placed down the boring and connected to an evacuated and metered canister. The hole will be sealed at the surface with wet bentonite or other inert material, and the sampling system will be purged of at least three sample chain volumes. Once purged, the canister will collect soil gas for one hour. The valve on the sample canister will then be closed and labeled appropriately. Soil gas samples will be analyzed for VOCs in accordance with EPA Method TO-15. 5.3.2 Subsurface Soil Sampling Soil samples will be collected by inserting an acetate sleeve into the hollow rod of the direct- push unit and extracting a soil core from each boring. The cores will be visually inspected for staining or discoloration, monitored for odors, and field screened using a photoionization detector (PID) calibrated to the isobutylene standard in order to detect VOCs. Samples will be taken from locations on the core with the highest readings—or from deepest part of the core if the PID does not have a positive reading—and transferred to 8 oz glass vials sealed with a polypropylene or phenolic open-top screw cap and a polytetrafluoroethylene (PTFE) septum. Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 10 The vials will then be labeled for identification and stored in an iced cooler. Soil samples will be analyzed for VOCs in accordance with EPA Method 8260B. Following all sampling, soil borings will be backfilled with soil cuttings and asphalt will be patched at the surface. 5.4 Investigation Derived Waste The generation of investigation-derived waste is not anticipated. Disposable sampling equipment will be double-bagged and disposed of as non-hazardous. Excess sample material will be returned to the sample location or disposed of according to accepted protocol. All hazardous materials generated, if any, will be disposed of in accordance with applicable federal, state, and local requirements, and in accordance with the U.S. EPA Office of Emergency and Remedial Response’s Management of Investigation-Derived Wastes During Site Inspection (U.S. EPA 1991) guidelines. 5.5 Analytical Parameters Chain-of-Custody forms will be developed using SCRIBE software. Samples will be shipped as environmental samples via strict chain-of-custody to a contract laboratory registered under the EPA’s Certified Laboratory Program and analyzed under Routine Analytical Services for the target compound list constituents and media as listed in the Sample Analysis Checklist (Table 3). 6.0 QUALITY CONTROL PROCEDURES QA/QC samples will be collected from the Site as a check of proper sample collection, field decontamination procedures, and laboratory procedures. Samples will be handled and preserved as outlined in the QAPP (Palmer et al. 2020). Every effort will be made to ship samples to the laboratory the day after the field sampling activity. Samples collected from the Site for QA/QC purposes include field duplicates from each matrix and additional soil sample volumes for laboratory matrix spike/matrix spike duplicates (MS/MSD). 7.0 CHAIN-OF-CUSTODY Samples will be handled and delivered to the CLP laboratory in accordance with chain-of- custody protocols within appropriate holding times, as defined by the QAPP (Palmer et al. 2020). 8.0 DATA REDUCTION, VALIDATION, AND REPORTING The data package delivered from the CLP laboratory will be validated by an EPA contractor. Following receipt of the validated analytical data, the project manager will prepare the Expanded Site Inspection 2 - Analytical Results Report (ESI 2-ARR). The analytical data in the validation package will be compared to the appropriate benchmark values in the Superfund Chemical Data Matrix, and background, or ambient, conditions. The project manager will prepare an assessment of whether the Site should be recommended for further action through CERCLA or alternate Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 11 authority. All data and observations collected as part of this ESI 2 will be included in the draft ESI 2-ARR and submitted to the EPA Region 8 for review and approval. 9.0 REFERENCES Center for Disease Control. 2018. “Facts About Benzene.” April 4, 2018. https://emergency.cdc.gov/agent/benzene/basics/facts.asp. ———. 2021a. “Toxic Substances Portal- Tetrachloroethylene (PERC).” Agency for Toxic Substances and Disease Registry. 2021. https://wwwn.cdc.gov/TSP/index.aspx. ———. 2021b. “Toxic Substances Portal- Trichloroethylene (TCE).” Agency for Toxic Substances and Disease Registry. 2021. https://wwwn.cdc.gov/TSP/index.aspx. Comer, Eldon. 1961. “Well Driller’s Report Well 57-3165.” Lehi, Utah. Davis, F.D. 2000. “Geologic Map of the Midvale Quadrangle, Salt Lake County, Utah.” Utah Geological Survey Map 177. Utah Department of Natural Resources. Frier, W.P. 2020. “Site Investigation Analytical Results Report - Maple Street Plume.” Utah DERR. Hely, A.G., R.W. Mower, C.A. Harr, and T. Arnow. 1971. “Water Resources of Salt Lake County, Utah.” Utah DNR Technical Publication 31. Hoyle, A.R. 2018. Interview with Alan Ryan Hoyle, Midvale City Water Master. Magna Water District. 2013. “Well Driller’s Report, Water Right 59-1295.” Magna, Utah. Minnesota Pollution Control Agency. 2006. “Guidelines: Natural Attenuation of Chlorinated Solvents in Ground Water,” 51. Palmer, Elizabeth, Muhammad Slam, Kim Viehweg, and Joseph Katz. 2020. “Quality Assurance Program Plan for Environmental Data Operations for the CERCLA Branch, Final Plan - Revision No. 8.” Utah Division of Environmental Response and Remediation. Pankow, J.F., and J.A. Cherry. 1996. Dense Chlorinated Solvents and Other DNAPLs in Groundwater. Portland, Oregon: Waterloo Press. Peterson Bros. Drilling Company. 1974. “Well Drillers Report for Well 57-7999.” Well Driller’s Report. Midvale, Utah. Salt Lake County Auditor. 1998. “1998 Midvale City Address Change.” Sandlin, W.R. 2022. “Expanded Site Inspection Work Plan - Maple Street Plume.” Utah DERR. Sandlin, W.R. 2023. “Expanded Site Inspection Analytical Results Report - Maple Street Plume.” Utah DERR. Expanded Site Inspection 2 Work Plan Maple Street Plume – UTN000820949 12 Schwille, Friedrich. 1988. Dense Chlorinated Solvents in Porous and Fractured Media: Model Experiments. Chelsea, Michigan: Lewis Publishers. Taylor, Neil B. 2019a. “Preliminary Assessment Worksheet - Maple Street Plume.” Utah DERR. ———. 2019b. “Site Investigation Work Plan - Maple Street Plume.” Utah DERR. Thiros, Susan A. 2010. “Conceptual Understanding of Groundwater Quality of the Basin-Fill Aquifer in Salt Lake Valley, Utah.” Professional Paper 1781. U.S. Geological Survey. U.S. Census Bureau. 2010. “2010 U.S. Census Bureau Data.” Utah Automated Geographic Reference Center. U.S. EPA. 1991. “Management of Investigation-Derived Wastes During Site Inspection.” ———. 2014. “Sampler’s Guide- Contract Laboratory Program Guidance for Field Samplers.” Washington, D.C.: Office of Superfund Remediation and Technology Innovation, U.S. EPA. Utah DEQ/DERR. 2016. “Draft Indoor Air Sample Protocol with Indoor Air Sample Information Collection Form.” Utah Division of Drinking Water. 2021. “Public Drinking Water Source Database.” Salt Lake City, UT: Utah Division of Drinking Water. Utah Division of Water Rights. 2020. “Water Rights Points of Diversion Database, Utah State Geographic Information Database Layer Name:Wrpad.Shp.” Watts, Peter. 2006. Tetrachloroethene. Concise International Chemical Assessment Document 68. Geneva: World Health Organization. Western Regional Climate Center. n.d. “MIDVALE, UTAH - Climate Summary.” Accessed December 19, 2014. http://www.wrcc.dri.edu/cgibin/ cliMAIN.pl?ut5610. FIGURES TABLES Ta b l e 1 . D a t a Q u a l i t y O b j e c t i v e s St e p 1 : Pr o b l e m S t a t e m e n t St e p 2 : Id e n t i f y i n g t h e De c i s i o n s St e p 3 : De c i s i o n I n p u t s St e p 4 : St u d y B o u n d a r i e s St e p 5 : De c i s i o n R u l e s St e p 6 : To l e r a n c e L i m i t s o n Er r o r s St e p 7 : Op t i m i z a t i o n o f S a m p l e De s i g n Ch l o r i n a t e d s o l v e n t co n t a m i n a t i o n w a s or i g i n a l l y i d e n t i f i e d i n t h e Mi d v a l e C i t y M u n i c i p a l Pa r k S t r e e t ( C o l d ) W e l l , wh i c h i s n o w c l o s e d . Se v e r a l h i s t o r i c l a u n d r o m a t s ex i s t u p g r a d i e n t t o t h e C o l d We l l . V i a t h e M a y 2 0 2 2 Ex p a n d e d S i t e I n s p e c t i o n (E S I ) , a l l t h e h i s t o r i c la u n d r o m a t s h a v e b e e n el i m i n a t e d f r o m s u s p i c i o n as s o u r c e s o f c o n t a m i n a t i o n , ex c e p t f o r t h e f o r m e r Fa s h i o n C l e a n e r s ( n o w Q u i k Pi k M a r k e t ) . Du e t o P C E a n d T C E v a l u e s fr o m s o i l g a s s a m p l i n g do w n g r a d i e n t f r o m a n d o n - si t e o f Q u i k P i k M a r k e t ex c e e d i n g V a p o r I n t r u s i o n Sc r e e n i n g L e v e l s ( V I S L ’ s ) an d / o r R e g i o n a l S c r e e n i n g Le v e l s ( R S L ’ s ) , h o m e s , ap a r t m e n t c o m p l e x e s , a n d bu s i n e s s e s i n t h e v i c i n i t y ma y b e a t r i s k o f s u b s u r f a c e va p o r i n t r u s i o n . T h e e x t e n t an d m e t h o d o f m i g r a t i o n re m a i n s u n k n o w n . Is t h e Q u i k P i k M a r k e t lo c a t i o n c o n t r i b u t i n g t o co n t a m i n a t i o n a t t h e Si t e ? Do e s t h e c o n t a m i n a t e d gr o u n d w a t e r p l u m e pr e s e n t a s i g n i f i c a n t ri s k t o h u m a n h e a l t h a t ne a r b y r e s i d e n t i a l a n d co m m e r c i a l p r o p e r t i e s th r o u g h v a p o r in t r u s i o n ? I f s o , w h a t i s th e e x t e n t o f t h e p l u m e an d e x t e n t o f t h e im p a c t ? Th e i n f o r m a t i o n r e q u i r e d t o ar r i v e a t a d e c i s i o n f o r t h i s s i t e in c l u d e s : Co l l e c t i o n o f s o i l g a s an d s o i l s a m p l e s do w n g r a d i e n t o f Q u i k Pi k M a r k e t a r o u n d ne a r b y h o m e s a n d bu s i n e s s e s , a n d i n ba c k g r o u n d l o c a t i o n s up g r a d i e n t f r o m Q u i k Pi k M a r k e t . Vo l a t i l e O r g a n i c An a l y s i s o f s a m p l e s . Ev a l u a t i o n o f d a t a t o de t e r m i n e p o s s i b l e co n t a m i n a n t s o u r c e s an d r i s k t o t a r g e t s . Co m p a r i s o n o f d a t a t o SC D M a n d V I S L be n c h m a r k s t o de t e r m i n e i f f u r t h e r wo r k u n d e r C E R C L A is w a r r a n t e d . Hu m a n h e a l t h i s t h e pr i m a r y t a r g e t o f in t e r e s t a t t h e S i t e . T h e Qu i k P i k M a r k e t lo c a t i o n w i l l b e t r e a t e d as a p o t e n t i a l s o u r c e o f co n t a m i n a t i o n d u r i n g th i s E S I . R e s i d e n t i a l an d c o m m e r c i a l pr o p e r t i e s do w n g r a d i e n t a n d ad j a c e n t t o t h e po t e n t i a l s o u r c e a r e a wi l l b e i n v e s t i g a t e d t o as s e s s t h e r i s k t o hu m a n h e a l t h . If c o n t a m i n a n t s a r e de t e c t e d i n s o i l g a s or s o i l a t co n c e n t r a t i o n s a b o v e SC D M a n d / o r V I S L co n c e n t r a t i o n s , t h e n fu r t h e r e v a l u a t i o n o f th e e x t e n t o f co n t a m i n a t i o n c o u l d be w a r r a n t e d . Sa m p l i n g w i l l b e co n d u c t e d a c c o r d i n g to m e t h o d s o u t l i n e d i n th e D E R R Q u a l i t y As s u r a n c e P r o g r a m Pl a n f o r E n v i r o n m e n t a l Da t a O p e r a t i o n s ( Q A P P ) of 2 0 2 0 a n d o t h e r re l e v a n t E P A g u i d a n c e do c u m e n t s . A l l a n a l y t i c a l da t a w i l l b e r e v i e w e d , Ve r i f i e d , a n d v a l i d a t e d ap p r o p r i a t e l y t o e n s u r e da t a a r e a c c e p t a b l e f o r t h e in t e n d e d u s e . Sa m p l i n g c o n d u c t e d du r i n g t h e E S I i n c l u d e s th e c o l l e c t i o n o f 1 3 s o i l ga s s a m p l e s a n d 1 3 s o i l sa m p l e s f r o m 1 2 d i r e c t pu s h b o r i n g l o c a t i o n s , in c l u d i n g a f i e l d d u p l i c a t e fo r e a c h m a t r i x a n d a n MS / M S D s a m p l e v o l u m e fo r s o i l . S a m p l i n g lo c a t i o n s a r e d e s i g n e d t o ta r g e t a r e a s o f h e i g h t e n e d po t e n t i a l v a p o r i n t r u s i o n in t o h o m e s , a p a r t m e n t co m p l e x e s , a n d bu s i n e s s e s d o w n g r a d i e n t of Q u i k P i k M a r k e t . Ta b l e 2 . S a m p l e L o c a t i o n s , D e s c r i p t i o n s , a n d R a t i o n a l e Sa m p l e I D M a t r i x L o c a t i o n R a t i o n a l e MS P -01 -SG So i l G a s In t h e p u b l i c w a y i n f r o n t o f 7 6 1 1 S G r a n t S t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -01 -SO So i l In t h e p u b l i c wa y i n f r o n t o f 7 6 1 1 S G r a n t S t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . L a b M S / M S D . MS P -02 -SG So i l G a s In t h e p u b l i c w a y i n f r o n t o f 7 6 6 7 S G r a n t S t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -02 -SO So i l In t h e p u b l i c w a y i n f r o n t o f 7 6 6 7 S G r a n t S t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -03 -SG So i l G a s In t h e p u b l i c w a y i n f r o n t o f 7 7 0 3 S G r a n t S t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P - 0 3 - S O So i l In t h e p u b l i c w a y i n f r o n t o f 7 7 0 3 S G r a n t S t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -04 -SG So i l Ga s In t h e g r a s s a r e a N E o f S t a t i o n a t M i d v a l e p a r k i n g . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -04 -SO So i l In t h e g r a s s a r e a N E o f S t a t i o n a t M i d v a l e p a r k i n g . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -05 -SG So i l G a s In t h e g r a s s a r e a W o f r o u n d a b o u t i n mi d d l e o f S t a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P - 0 5 - S O So i l In t h e g r a s s a r e a W o f r o u n d a b o u t i n m i d d l e o f S t a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -06 -SG So i l G a s In t h e p u b l i c w a y N s i d e o f t h e n o r t h b u i l d i n g o f St a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -06 -SO So i l In t h e p u b l i c w a y N s i d e o f t h e n o r t h b u i l d i n g o f S t a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -07 -SG So i l G a s In t h e p u b l i c w a y E s i d e o f t h e N o r t h b u i l d i n g o f St a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -07 -SO So i l In t h e p u b l i c w a y E s i d e o f t h e N o r t h b u i l d i n g o f S t a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -08 -SG So i l G a s In t h e p u b l i c w a y E s i d e o f t h e m i d d l e g a p a t S t a t i o n a t Mi d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -08 -SO So i l In t h e p u b l i c w a y E s i d e o f t h e m i d d l e g a p a t S t a t i o n a t M i d v a l e . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -08 -SG -FD So i l G a s In t h e p u b l i c w a y E s i d e o f t h e m i d d l e g a p a t S t a t i o n a t M i d v a l e . Fi e l d D u p l i c a t e . MS P -08 -SO -FD So i l In t h e p u b l i c w a y E s i d e o f t h e m i d d l e g a p a t S t a t i o n a t M i d v a l e . Fi e l d D u p l i c a t e . MS P -09 -SG So i l G a s In t h e p u b l i c w a y S W o f C a n y o n L o d g e # 1 3 , N o f Q u i k P i k M a r k e t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -09 -SO So i l In t h e p u b l i c w a y S W o f C a n y o n L o d g e # 1 3 , N o f Q u i k P i k M a r k e t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -10 -SG So i l G a s In t h e p u b l i c w a y W o f Q u i k P i k M a r k e t a c r o s s r o a d . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -10 -SO So i l In t h e p u b l i c w a y W o f Qu i k P i k M a r k e t a c r o s s r o a d . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -11 -SG So i l G a s In t h e p a r k i n g l o t S o f Q u i k P i k M a r k e t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -11 -SO So i l In t h e p a r k i n g l o t S o f Q u i k P i k M a r k e t . Id e n t i f y c o n t a m i n a n t c o n c e n t r a t i o n . MS P -12 -SG So i l G a s In t h e N W c o r n e r o f M i d v a l e C e n t e r S t a t i o n P a r k i n g . Es t a b l i s h b a c k g r o u n d s o i l g a s c o n c e n t r a t i o n . MS P -12 -SO So i l In t h e N W c o r n e r o f M i d v a l e C e n t e r S t a t i o n P a r k i n g . Es t a b l i s h b a c k g r o u n d s o i l c o n c e n t r a t i o n . Ta b l e 3 . S a m p l e A n a l y s i s C h e c k l i s t Sa m p l e I D M a t r i x La b o r a t o r y A n a l y s e s Q A / Q C O t h e r VOCs SVOCs Pesticides Metals PCB Cyanide Sulfide Ammonia NO3-NO2 Anions Asbestos Spec. Org. BTEXN TPH O&G Explosives Field Dup. Lab MS/MSD Split Spike Blank Opportunity Background MS P - 0 1 - S G So i l G a s X MS P -01 -SO So i l X X MS P -02 -SG So i l G a s X MS P -02 -SO So i l X MS P - 0 3 - S G So i l G a s X MS P -03 -SO So i l X MS P -04 -SG So i l G a s X MS P -04 -SO So i l X MP S -05 -SG So i l G a s X MS P -05 -SO So i l X MS P -06 -SG So i l G a s X MS P -06 -SO So i l X MS P -07 -SG So i l G a s X MS P -07 -SO So i l X MS P -08 -SG So i l G a s X MS P -08 -SO So i l X MS P -08 -SG -FD So i l G a s X X MS P -08 -SO -FD So i l X X MS P -09 -SG So i l G a s X MS P -09 -SO So i l X MS P -10 -SG So i l G a s X MS P -10 -SO So i l X MS P -11 -SG So i l G a s X MS P -11 -SO So i l X MS P -12 -SG So i l G a s X X MS P -12 -SO So i l X X APPENDIX A Site Health and Safety Plan Health and Safety Plan Maple Street Plume Midvale, Utah A. Site Hazard Evaluation Previous sampling at the Site indicate the presence of tetrachloroethene (PCE), trichloroethene (TCE), and benzene in soil gas; and the presence of PCE in groundwater. The primary exposure pathways include adsorption through the skin and inhalation of vapors volatilized from contaminated soil or groundwater. The relatively low concentrations detected at the Site do not present an acute exposure risk to those collecting the samples. No other known environmental or chemical hazards exist at the Site. No special site entry procedures will be necessary. On-site hazards include slip, trip, and falls; weather related hazards; and hazards associated with working around a direct- push unit, including underground hazards such as utility lines. B. Site Investigation Team Wes Sandlin Project Manager TBD Site Health & Safety Officer C. Personal Protection Equipment (PPE) Based on the minimum exposure expectation at the Site, Level D personal protective equipment (PPE) will be worn by workers at all times. However, if site conditions change during sampling activities, all work on-Site will stop and the appropriate PPE level will be re-evaluated. D. Surveillance and Monitoring Equipment On-Site air monitoring will not be required based on characteristics and concentrations of likely exposure. E. Disposal of Investigation Derived Material Decontamination solutions and used PPE will be handled, stored, and disposed of appropriately. F. Emergency Information Police, Fire, Medical, and other Emergencies 911 Intermountain Medical Center (route map attached) 801-507-7000 Local City/County Health Department 385-468-4100 Utah Poison Control Center 1-800-222-1222 Blue Stake Location Service 1-800-662-4111 APPENDIX B Consent for Access to Property