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Home My WebLink About18019_Standard_Uniform_AWPBrownfields Assessment Work Plan Standard Uniform Site 600 Phillip Davis Drive Charlotte, North Carolina Brownfields Project ID 18019-14-060 September 5, 2014 H&H Job No. SFR-002 #C-1269 Engineering #-245 Geology Brownfields Assessment Work Plan Standard Uniform Site 600 Phillip Davis Drive Charlotte, North Carolina H&H Job SFR-002 Table of Contents Section Page No. 1.0 Introduction and Background Information ........................................................................ 1 2.0 Surface Water Sampling ....................................................................................................... 3 3.0 Receptor Survey ..................................................................................................................... 4 4.0 Vapor Intrusion Assessment ................................................................................................. 5 4.1 Sub-slab Soil Vapor Sampling ............................................................................................. 5 4.2 Indoor Air Sampling (If Warranted) ..................................................................................... 6 5.0 Reporting ................................................................................................................................ 8 Figures Figure 1 Site Location Map Figure 2 Sample Location Map i S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc Brownfields Assessment Work Plan Standard Uniform Site 600 Phillip Davis Drive Charlotte, North Carolina H&H Job SFR-002 1.0 Introduction and Background Information Hart & Hickman, PC (H&H) has prepared this Brownfields Assessment Work Plan for the Standard Uniform Brownfields site located at 600 Phillip Davis Dr. in Charlotte, North Carolina. A site map is included as Figure 1. The site contains an approximate 21,000 square-foot building that contains a party rental supply facility. The building contains an office/showroom area and a warehouse area for storage and maintenance of rental equipment. A site plan is included as Figure 2. The site was formerly operated from 1982 to 2000 by Standard Uniform which conducted uniform supply and cleaning. As part of that process, dry cleaning was performed in the southeastern portion of the warehouse area (see Figure 2). To assess the potential for impact from historical dry cleaning activities, H&H conducted groundwater sampling on the eastern and northeastern portion of the site in July 2013. The locations of the groundwater samples, labeled TW-1, TW-2, and TW-3, are indicated in Figure 2. Results of analysis of the groundwater samples are summarized in Table 1. The results indicated that no compounds were detected in well TW-1 from the northeastern portion of the site. However, the drycleaning solvent tetrachloroethene (PCE) and its degradation products trichloroethene (TCE), cis-1,2-dichloroethene (cis-1,2-DCE), and vinyl chloride were detected in the groundwater samples collected from wells TW-2 and TW-3 on the eastern side of the site above North Carolina groundwater standards. The highest concentrations were detected in well TW-3 located closest to the area of the former drycleaner. In TW-3. PCE was detected at a concentration of 18,900 µg/l. In addition, the detected concentrations of PCE and TCE in TW-2 and TW-3 were above the DENR Division of Waste Management Non-Residential Vapor Intrusion Screening Levels. 1 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc In April 2014, the current property owner SFRH Charlotte Flip LLC applied for Brownfields program eligibility, and a letter of eligibility was received from the DENR Brownfields Program on May 28, 2014. To evaluate potential risks associated with the site and its future use, H&H has prepared this work plan for additional assessment. The proposed work plan activities includes a receptor survey, surface water sampling, sub-slab soil vapor sampling and, if warranted, indoor air sampling. The following sections describe the methods of the proposed additional assessment activities. 2 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc 2.0 Surface Water Sampling A tributary of Irwin Creek borders the eastern and northern edges of the site property. To evaluate the potential for stream impact from discharging groundwater, H&H proposes to collect surface water samples from one upgradient and one downgradient location at the site. The approximate proposed locations of the samples are indicated in Figure 2. The samples will be collected under expected baseflow conditions (i.e., not during or soon after a rain event) by placing the sample jars directly into the flowing water and allowing the bottles to fill slowly. The samples will be collected moving upstream in order to minimize the potential for cross contamination. The surface water samples will analyzed for volatile organic compounds (VOCs) by EPA Method 8260. 3 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc 3.0 Receptor Survey As part of the assessment activities, a Brownfields receptor survey will be completed for the site and nearby area. The receptor survey will be completed in accordance with the Brownfields Receptor Survey Guidance form. The receptor survey will include information about land use in the site area, and a search for water supply wells, basements, utility manways and chases, storm sewers, other underground utilities, drains, and surface water within the site area. 4 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc 4.0 Vapor Intrusion Assessment 4.1 Sub-slab Soil Vapor Sampling To assess the potential for vapor intrusion into the site buildings from identified groundwater impacts, H&H proposes to collect six sub-slab soil vapor samples at the site. The proposed sampling locations are provided in Figure 2. The samples will be collected from the following locations: • Two samples from the office/showroom area • One sample from the area of the former drycleaning machines in the southeastern part of the warehouse • Three samples from the remainder of the warehouse area, biased to the eastern side where the drycleaning machines were located Please note that the locations may need to be modified in the field based upon site access constraints. At each sample location, H&H will drill through the concrete floor utilizing a concrete hammer drill and an approximate 1.5-inch diameter bit. Through each of the drilled holes, H&H will install an approximate 0.625-inch diameter stainless steel probe with approximate 2-inch long bottom screen point. The probes will be installed through the gravel beneath the concrete slab and seated in the underlying soil so that the soil gas probe screen is present in both the soil and overlying gravel. If no gravel is present beneath the slab at the sample location, the probe will be advanced no more than 6 inches below the bottom of the slab into soil. After pushing the screen point to the desired depth, the stainless steel screen of the point will be opened. Each point will then be sealed at the surface of the concrete slab using hydrated bentonite. The soil gas probes will be completed at the surface using a sample valve and Teflon tubing. Prior to sampling, a leak check will be conducted at each vapor monitoring point by constructing a shroud around the sampling point and saturating the air within the shroud with helium gas. Using a syringe, a sample will be collected from the gas in the shroud into a 5 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc Tedlar® bag and analyzed for helium concentrations using a helium gas detector. Vapor from the vapor monitoring point will be purged and sampled outside of the shroud into a separate Tedlar® bag and analyzed using the helium gas detector to ensure that helium concentrations are less than 5% of the helium concentrations detected in the shroud. Following a successful field leak check, vapor samples will be collected into a one-liter Summa canisters for laboratory analysis. The Summa canisters will be allowed to fill slowly using an airflow regulator over a period of approximately 10 minutes per point (approximately 100 ml/min). H&H will also collect measurements of ambient temperature at the time of sample collection. In addition, outside weather will be noted during the sampling period. After sampling, each of the points will be abandoned and the surface will be patched. Once the soil vapor samples are collected, the canisters will be shipped to a qualified laboratory for analysis of VOCs by EPA Method TO-15. 4.2 Indoor Air Sampling (If Warranted) Following collection and receipt of the sub-slab soil vapor sampling data, H&H will summarize the sample data in a table and provide it to DENR for review. If sub-slab soil sample compound concentrations are less than their respective Division of Waste Management Non-Residential Soil Gas Screening Levels, then indoor air sampling will not be warranted. However, if concentrations of compounds are detected above screening levels, H&H will propose to DENR locations of indoor air samples and the proposed analytes for review and approval. Prior to the indoor air sampling, H&H will review material safety data sheets to verify that compounds detected in sub-slab soil vapor are not being used at the facility. If they are, then alternative means for evaluating indoor air risks may need to be evaluated. The indoor air samples will be collected with 6-liter Summa canisters. The Summa canister will be connected to an airflow regulator and a 3 ft long sampling cane. The typical height of a 6 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc Summa canister with an attached airflow regulator is approximately 2 ft above grade and, with the additional 3-foot long sampling cane, the sample intake point is approximately 5 ft above grade (typical breathing zone height). Prior to sample collection, H&H will measure the wind direction and select an exterior background location which is located upgradient of the site building. The location of the background sample will be determined the day of the sampling based upon the wind direction. The background location Summa canister will also be fitted with a regulator and sampling cane so that the sample height is approximately 5 ft above ground level. Following set-up of the background sample canister, the indoor and background sample valves will be opened and the samples will be collected over an approximate 8-hour period (the regulator will be pre-set to collect samples over the 8-hour period). As part of the sampling effort, H&H will measure the indoor/outdoor air pressure differential at representative sampling locations near the start, middle, and end of the 8-hour sampling period using a manometer sensitive to 0.01 inches water. In addition, exterior wind speed, exterior wind direction, and indoor/outdoor temperature will be recorded near the start, middle, and end of the sampling period. Precipitation trends will also be noted prior to and during the sampling event. Following collection, the samples will be submitted to a laboratory for analysis of by EPA Method TO-15 for the DENR agreed upon analytes based upon the soil vapor sampling. 7 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc 5.0 Reporting Upon completion of the field activities and receipt of the analytical data, H&H will prepare a report which describes the methods and results of the Brownfields assessment activities. The report will include the methods and results of the surface water sampling, receptor survey, sub- slab soil vapor sampling, and indoor air sampling (if warranted). In addition, the report will include figures showing the sample locations, tabular summaries of the data in comparison to regulatory screening levels, laboratory analytical reports, and conclusions concerning the activities. 8 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Brownfields Work Plan.doc Table 1 (Page 1 of 1) Summary of Groundwater Analytical Data Standard Uniform Site 600 Phillip Davis Dr Charlotte, North Carolina H&H Job No. SFR-002 S:\AAA-Master Projects\SFRH Charlotte Flip\BF Assessment Work Plan\Phse II GW Table.xls 9/5/2014 Table 1 (Page 1 of 1) Hart & Hickman, PC Analytical Method Sample ID TW-1 TW-2 TW-3 Sample Date 7/16/2013 7/29/2013 7/29/2013 Units (µg/L)(µg/L)(µg/L)(µg/L)(µg/L) VOCs (8260B) cis-1,2-Dichloroethene <1.0 278 22.3 60 NE Tetrachloroethene <1.0 1,580 18,900 0.7 48.4 Toluene <1.0 <1.0 7.56 600 16,100 Trichloroethene <1.0 97.0 27.1 3 4.35 Vinyl Chloride <1.0 3.51 <1.0 0.03 24.5 Notes: 1) North Carolina Department of Environment and Natural Resources 2L Groundwater Standard (July 2012) 2) North Carolina Division Of Waste Management Non-Residential Vapor Intrusion Groundwater Screening Level (June 2014) Only those compounds detected in at least one sample shown above Bold indicates an exceedance of the NC 2L Standards Bold indicates an exceedance of the Non-Residential Vapor Intrusion Groundwater Screening Level Method number follows parameter in parenthesis VOCs = volatile organic compounds (µg/L) = micrograms per liter VOCs (8260)North Carolina Groundwater Standard1 Vapor Intrusion Screening Level2 0 2000 4000 APPROXIMATE SCALE IN FEET N U.S.G.S. QUADRANGLE MAP QUADRANGLE7.5 MINUTE SERIES (TOPOGRAPHIC) TITLE PROJECT SITE LOCATION MAP 600 PHILLIP DAVIS DRIVE CHARLOTTE, NORTH CAROLINA DATE: JOB NO: REVISION NO: FIGURE: 8-13-13 0 1BCP-039 SITE 2923 S. Tryon Street, Suite 100Charlotte, NC 28203704.586.0007(p) 704.586.0373(f)CHARLOTTE WEST 1996 0 100 200 APPROXIMATE SCALE IN FEET N TITLE PROJECT SAMPLE LOCATION MAP 600 PHILLIP DAVIS DRIVECHARLOTTE, NORTH CAROLINA DATE: JOB NO: REVISION NO: FIGURE: 09-02-14 0 2SFR-002 TW-1 Previous Temporary Monitor Well Location Approximate Proposed Sub-Slab Sample Location Approximate Proposed Surface Water Sample Location Warehouse Office/Showroom TW-3 TW-1 Approximate Property Boundary TW-2 Approximate Location of Former Dry-Cleaning Equipment