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Home My WebLink AboutDSHW-2018-005569 - 0901a0688084eb74WASATCH ENVIRONMENTAL Mr. Ken Rudy Price Realty 230 East South Temple Salt Lake City, Utah 84104 I Co Div of Waste Management and Radiatjon Control MAY 2 4 2018 DS 4\14- ZO15- 005 561 April 24, 2018 Project No. 1995-013A SUBJECT: Phase II Environmental Site Assessment - Subsurface Investigation LearnKey Property 691 North 400 West Salt Lake City, Utah Wasatch Environmental Inc., (Wasatch) has completed subsurface investigation activities at the LearnKey property (Site), located at 691 North 400 West, Salt Lake City, Utah. The investigation activities consisted of advancing seven soil borings to facilitate the collection of soil and groundwater samples, and the collection of one sub-slab soil gas sample. BACKGROUND Wasatch prepared a Phase I Environmental Site Assessment (ESA) on the Site dated March 27, 2018, on behalf of Price Realty Group. Wasatch identified the following recognized environmental conditions during the completion of the March 2018 Phase I ESA: • The Site was originally developed in 1961 and included additions of warehouses to the west and an expansion of the office to the north through 1968. A map from 1965 shows a sand trap to the north of the original office, and this area was subsequently developed with an expansion of the current office. Tenants have included an electronics company (Geotron Corp., 1962), an engineering and manufacturing company (Specialty Engineering & Manufacturing Company, machine shop, 1963 through 1982), a printing business (Quality Press, 1983 through 2004), an automotive restoration company that included a paint booth (at least 2007), and advertising companies (2007 to present). Former tenants from 1962 through 2007 would have likely used a combination of petroleum products and hazardous substances, including solvents, in daily business operations. The potential release of petroleum products and hazardous substances at the Site for over 45 years is considered a recognized environmental condition. OBJECTIVES The current scope of work was intended to evaluate the Site for environmental impacts related to the past uses of the property. The environmental sampling activities were not intended to fully delineate all potential releases to the Site. FIELD METHODOLOGY Soil Sampling On April 6, 2018, Wasatch Project Hydrogeologist, Blake Downey, P.G., and Field Geologist, Steve Strehl, directed the completion of seven soil borings (GP-1 through GP-7), using direct-push drilling 2410 WEST CALIFORNIA AVENUE • SALT LAKE CITY, UTAH 84104 PHONE (801) 972-8400 • FAX (801) 972-8459 Website: www.wasatch-environmentaLcom • e-Mail: wei@wasatch-environmentaLcom techniques, to evaluate soil and groundwater conditions at the Site. Direct Push Services (DPS) advanced the soil borings using a GeoProbe Model 7822 DT. The boring locations are shown on Figure 1. Each of the soil borings were advanced to a depth of 15 feet below ground surface (bgs). Soil samples from the borings were collected using 5-foot long, by 1.5-inch diameter, discrete interval push samplers equipped with disposable polybutyrate liners. Drill rods were decontaminated between each soil boring. The soil cores were field logged by an experienced geologist. The field logging included a description of color, consistency, odor, staining, and soil type based on the Unified Soil Classification System. The soil cores were screened in the field with a photoionization detector (PID) equipped with a 10.6 electron volt (eV) lamp. The PID was calibrated with a 100-parts per million (ppm) isobutylene standard calibration gas. The PID is utilized to identify soils which may have been impacted by volatile organic compounds (VOCs) such as those found in petroleum fuels and some solvents. The collection of soil samples for laboratory analysis was not originally anticipated; however, based on observed soil impacts in soil boring GP-2, one soil sample was collected from the depth interval exhibiting the most significant indications of contamination based on field screening and field observations. No other soil samples were submitted for laboratory analysis. Soil samples were collected with gloved hands. The soil sample collected for VOCs and semi-volatile organic compounds (SVOCs) was collected into 4-ounce glass jars and immediately placed in a cooler with ice. The soil VOC and SVOC sample was delivered under chain-of-custody protocol to American West Analytical Laboratories (AWAL), a Utah-Certified analytical laboratory for analysis of VOCs by United States Environmental Protection Agency (U.S. EPA) Method 8260C and SVOCs by U.S. EPA Method 8270D full scan and single selected ion mode (SIM). Following the completion of sampling activities, the borings were backfilled with bentonite pellets, hydrated, and patched with asphalt or concrete to match the existing surface at each boring location. Groundwater Sampling Groundwater samples were collected from each of the soil borings (GP-1 through GP-7). The boring locations are shown on Figure 1. Groundwater samples were collected using a stainless steel well-point and a peristaltic pump. Groundwater was initially purged from the borings to reduce the turbidity of the samples; however, groundwater production was very low resulting' in turbid samples. Groundwate? samples collected for VOCs were dispensed into 40-milliliter capacity, glass vials with Teflon® septa caps. The vials, which were supplied by the analytical laboratory, and contained several drops of hydrochloric acid as a preservative. The vials were filled slowly until a meniscus formed at the top of each vial, then each vial was sealed with a septa cap. This procedure eliminates headspace within the vials and minimizes the loss of volatiles. Groundwater samples collected for SVOCs were dispensed into three 80 mL, unpreserved, amber glass vials. The sample vials/bottles were each labeled with the sample location, sample identification, date and time of sample collection, and requested analysis. The samples were placed in a cooler with ice and transported under chain-of-custody protocol to AWAL for analysis. Groundwater samples were analyzed for VOCs by U.S. EPA Method 8260C and SVOCs by U.S. EPA Method 8270D full scan and SIM. All groundwater sampling supplies were disposable; therefore, decontamination of sampling equipment was not required. Sub-Slab Soil Gas Sampling On April 6, 2018, Wasatch Project Hydrogeologist, Blake Downey, P.G., collected one sub-slab soil gas sample (SUB-1) near the former sand trap located beneath the northeast floor slab of the building. The sample location is shown on Figure 1. Techniques for collecting the soil gas sample began by checking for a vacuum in the 6-liter Summa canister supplied by ALS Laboratories (ALS). The initial vacuum was recorded on the chain-of-custody form provided by ALS. A %-inch hole was drilled through the concrete slab at the sampling location using a percussion hammer drill to a depth of approximately 1% feet below the concrete slab. A brass vapor pin equipped with a silicone sleeve was inserted into the hole and a Wasatch Environmental Inc. Page 2 bentonite paste seal was placed around the silicone sleeve and vapor pin. Next, tubing was attached to the vapor pin. The bentonite paste was allowed to set for a minimum of %-hour while the hole equilibrated. A sample regulator equipped with a flow restrictor was provided by ALS for the sample. A sample regulator was attached to the 6-liter Summa sample canister. The tubing from the vapor pin was then attached to the sample regulator and the valve on the sample canister was opened. The vacuum gauge on the flow restrictor was monitored, with decreasing vacuum indicating that soil gas was being collected into the sample canister. The sample was collected for approximately %-hour. Alcohol pads were placed near the drilled hole and near the Summa canister to check for leaks. The final vacuum was recorded on the chain-of-custody form provided by ALS. The valve on the sample canister was then closed, sample regulator removed, and brass cap tightened to the inlet of the sample canister. The vapor pin was removed from the hole and the hole was filled and finished with concrete. The sample canister was labeled with the appropriate sample location, as well as initial and final vacuum readings. Chain-of- custody documentation was completed, and the sample was delivered to ALS for analysis of VOCs using U.S. EPA Method TO-15. FIELD OBSERVATIONS AND LABORATORY ANALYTICAL RESULTS Soil Samples Soils at the Site generally consist of fill, gravelly sand (SW), sandy silt (ML), silty sand (SM), and some silty clay (CL). It appears the fill material is 5 to 7 feet in thickness and consists mainly of gravelly sand and some silty clay with red bricks, concrete, glossy rubber like material, and wood debris. Depth to groundwater was approximately 6 feet bgs. A grease like substance was observed in soil boring GP-2. PID readings ranged from 0.0 to 15 ppm. Boring logs are presented in Appendix A. Analyte concentrations in soil were compared to the U.S. EPA Regional Screening Levels (RSLs) for Industrial Soil and the U.S. EPA RSLs for Residential Soil. Soil analytical data is summarized in Table 1. Sampling locations are shown on Figure 1. The laboratory analytical report and chain of custody documentation are presented in Appendix B. Soil sample GP-2-6' exhibited a benzo(a)anthracene concentration of 21,100 micrograms per kilogram (pg/kg), exceeding the U.S. EPA RSL for Industrial Soil for benzo(a)anthracene of 21,000 pg/kg. Soil sample GP-2-6' exhibited a benzo(a)pyrene concentration of 11,100 pg/kg, exceeding the U.S. EPA RSL for Industrial Soil for benzo(a)pyrene of 2,100 pg/kg. Soil sample GP-2-6' exhibited a naphthalene concentration of 20,800 pg/kg, exceeding the U.S. EPA RSL for Industrial Soil for naphthalene of 17,000 pg/kg. Soil sample GP-2-6' exhibited a dibenz(a,h)anthracene concentration of 8,450 pg/kg, exceeding the U.S. EPA RSL for Industrial Soil for dibenz(a,h)anthracene of 2,100 pg/kg. Soil sample GP-2-6' exhibited a indenol(1,2,3-cd)pyrene concentration of 1,960 pg/kg, exceeding the U.S. EPA RSL for Residential Soil for indenol(1,2,3-cd)pyrene of 1,100 pg/kg, but below the U.S. EPA RSL for Industrial Soil of 21,000 pg/kg. Soil sample GP-2-6' exhibited a benzo(b)fluoranthene concentration of 12,500 pg/kg, exceeding the U.S. EPA RSL for Residential Soil for benzo(b)fluoranthene of 1,100 pg/kg, but below the U.S. EPA RSL for Industrial Soil of 21,000 pg/kg. Soil sample GP-2-6' exhibited a 1-methylnaphthalene concentration of 40,900 pg/kg, exceeding the U.S. EPA RSL for Residential Soil for 1-methylnaphthalene of 18,000 pg/kg, but below the U.S. EPA RSL for Industrial Soil of 73,000 pg/kg. Wasatch Environmental Inc. Page 3 No other SVOCs were detected in soil at concentrations exceeding their applicable U.S. EPA RSL for Industrial or Residential Soil. No VOCs were detected at concentrations exceeding their applicable U.S. EPA RSL for Industrial or Residential Soil. Groundwater Samples Analyte concentrations in groundwater were compared to the U.S. EPA Federal Maximum Contaminant Levels (MCLs). Analyte concentrations in groundwater are presented in Table 2. Sample locations are shown on Figure 1. The laboratory analytical report and chain of custody documentation are presented in Appendix B. Groundwater samples GP-2 (2.10 micrograms per liter [pg/L]), GP-5 (129 pg/L), GP-6 (34.5 p /L), and GP-7 (1.49 pg/L) exhibited benzo(a)pyrene concentrations in excess of the U.S. Federal MCL for benzo(a)pyrene of 0.2 pg/L. Benzo(a)pyrene was not detected in groundwater samples GP-1, GP-3, or GP-4. The following SVOCs were detected in one or more groundwater samples at concentrations below their applicable U.S. EPA Federal MCLs (if established): 2,4-dimethylphenol, 2-methylphenol, 3&4- methylphenol, 1-methylnaphthalene, 2-methylenaphthalene, acenaphthene, acenaphthylene, anthracene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(g,h,i)perilene, benzo(k)fluoranthene, carbazole, chrysene, dibenzofuran, fluoranthene, fluorene, indene, indenol(1,2,3-ce)pyrene, naphthalene, phenanthrene, and pyrene. No VOCs were detected in any of the groundwater samples. Sub-Slab Soil Gas Samples Analyte concentrations in sub-slab soil gas were compared to U.S. EPA Vapor Intrusion Screening Level (V1SL) Residential Target Sub-slab and Exterior Soil Gas Concentrations and the U.S. EPA VISL Commercial Target Sub-slab and Exterior Soil Gas Concentrations; from the U.S. EPA VISL calculator spreadsheet, version 3.5.2. Sub-slab soil gas analytical data are summarized in Table 3. The laboratory analytical report is presented in Appendix B. Sample locations are shown on Figure 1. The following VOCs were detected in the sub-slab soil gas sample at concentrations below their applicable U.S. EPA VISL Residential Target Sub-slab and Exterior Soil Gas Concentration (if established): dichlorodifluoromethane, Freon 11, acetone, carbon disulfide, methylene chloride, 2- butanone, 4-methy1-2-pentanone, hexane, tetrahydrofuran, benzene, cyclohexane, heptane, toluene, tetrachloroethene (PCE), ethylbenzene, m,p-xylene, o-xylene, 1,3,5-trimethylbenzene, and 1,2,4- trimethylbenzene. No other VOCs were detected in the sub-slab soil gas sample. CONCLUSIONS AND RECOMMENDATIONS Only boring location GP-2 exhibited field indications (staining and odors) of a release to the environment of what appeared to be a petroleum product. Therefore, a single soil sample was collected from this boring, and several SVOCs detected exhibited concentrations in excess of the U.S. EPA RSL for Industrial Soil, as well as others that exceeded the U.S. EPA RSL for Residential soil. Fill material was observed across the Site and ranged from 5 to 7 feet in thickness. The fill material consisted mainly of gravelly sand and some silty clay with red bricks, concrete, trace glossy rubber like material, and wood debris. Wasatch Environmental Inc. Page 4 Blake Downey, P.G. Project Hydrogeologist Given that benzo(a)pyrene impacts to groundwater appear to be the highest near the center of the building, where there was no field indication of a release, it is Wasatch's opinion, that the fill material located at the Site may be impacted by SVOCs. The origins of the fill material are unknown at this time, and it has been Wasatch's experience that SVOC-impacted fill material has been used in the Salt Lake Valley area in the past. Increased benzo(a)pyrene concentrations in groundwater may have been elevated due to the turbidity of the groundwater samples collected. It is Wasatch's opinion, that the SVOC impacts to soil and groundwater at the Site be reported to the Utah Department of Environmental Quality. Wasatch recommends additional investigation activities be conducted at the Site to delineate the SVOC impacts that are present. Our services consist of professional opinions and recommendations made in accordance with generally accepted environmental engineering principles and practices. This warranty is in lieu of all other warranties either expressed or implied. Should you have any questions, please do not hesitate to contact us. Sincerely, WASATCH ENVIRONMENTAL, INC. Rebecca Studenka Senior Geologist and Senior Project Manager UST Certified Consultant FIGURES Figure 1 — Sample Location Map TABLES Table 1 — Soil Analytical Data Table 2 — Groundwater Analytical Data Table 3 — Sub-Slab Soil Gas Analytical Data APPENDICES Appendix A — Boring Logs Appendix B — Laboratory Analytical Reports Wasatch Environmental Mc. Page 5