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HomeMy WebLinkAbout19010_DCC Apartments_Soil Gas Sampling Report_2016.06.22 Professional Service Industries, Inc ● 5021-A West W.T. Harris Boulevard, Charlotte, NC 28269 ● Phone 704/598-2234 ● Fax 704/598-2236 June 22, 2016 Mr. David Klepser Email: dklepser@ramrealestate.com DCC Parcel B Plus LLC C/o Ram Development Company 1930 Camden Road, Suite 130 Charlotte, North Carolina 28203 RE: Report of Soil-Gas Sampling Assessment Proposed DCC Mix Use Development 126, 128, and 130 West Worthington Avenue Charlotte, North Carolina 28203 PSI Project Number 0457928-1 Dear Mr. Klepser: Professional Service Industries (PSI) is pleased to provide this report summarizing the laboratory data generated from the analysis of soil gas samples collected at the above referenced site as part of the client’s North Carolina Department of Environmental Quality (NCDEQ) Brownfields application. The soil gas samples were collected at your request and pursuant to the scope of work and general conditions associated with PSI’s proposal (0457-171592 Revision-1) dated February 25, 2016 and authorized by Mr. David Klepser on May 23, 2016. Site Descriptions and Features The subject property consists of one land parcel referenced by Mecklenburg County Parcel Identification Number (PIN) 12101401, encompassing approximately 0.28 acres, and is located in the northeast quadrant of West Worthington Avenue and Hawkins Street in Charlotte, North Carolina (Figure 1). The subject property is improved with one single- story commercial structure (approximately 7,600 square feet) consisting of four contiguous buildings. The current configuration of the building was completed in 1969; while the original building (northern portion, 1817 Hawkins street) was originally constructed in 1951, the two buildings located at 126 and 128 West Worthington Avenue were constructed approximately in 1962, and the last building 130 West Worthington Avenue was constructed in 1966. Currently the 1817 Hawkins Street building is occupied by Crazy Jane, an interior design firm, the 124 West Worthington Avenue building is occupied by Just Janet Company, a beauty salon, the 128 West Worthington Avenue Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 2 of 7 building is currently vacant, and the 130 West Worthington Avenue building is occupied by Yellow Duck, a marketing/advertising firm. Based on review of the Mecklenburg County GIS Mapping Service (Polaris 3G), the subject property has been used for commercial purposes dating back to 1951. Prior to the development of the first building in 1951, the subject property was vacant cleared land dating back to 1905. In 1951, the first structure was placed on the subject property (1817 Hawkins Street). Based on historical Sanborn fire insurance maps, this structure was utilized as a building material warehouse. Two (2) additional buildings were constructed on the subject property around 1962 (126 and 128 West Worthington Avenue). Based on the Sanborn maps, these buildings were utilized for commercial purposes with office and warehouse space for painting and steel fabrication and storage. The last structure (130 West Worthington Avenue) was constructed around 1966. Based on city directory review, the subject property was utilized for light industrial purposes until the mid to late 1990s when the buildings were converted to retail and office space. Current use of the surrounding properties consists of the following:  Northeast – Commercial developed land followed by West Boulevard and multi- family residence  Southeast – Commercial developed land with paved parking area followed by Camden Road and the Charlotte Light Rail System  Southwest – West Worthington Avenue followed by multiple commercial structures.  Northwest – Hawkins Street followed by multiple commercial structures. A site vicinity map is provided as Figure 2. Past uses of the adjoining/surrounding properties include residential, light manufacturing, mills, and commercial. No gasoline stations were indicated by the historical sources reviewed. The northeast adjoining commercial properties appear to be first developed around 1962. Prior to being developed for commercial use, the northeast adjoining properties appear to be residential dating back to 1929. The southeast adjoining commercial properties appeared to be developed around 1968. Prior to being developed for commercial use, the southeast adjoining property was developed for residential use dating back to 1929. The southwest adjoining property appeared to be first developed in 1949 as an expansion to the Nebel Knitting operations located on the eastern property parcel (101 West Worthington Avenue). This building was referred to as the Nebel Knitting Mill Annex, which was in operation until Nebel Knitting was acquired by Chadbourn, Inc. in 1968. The use of the building while Chadbourn, Inc. operated and owned the property is unknown. However, in the Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 3 of 7 mid-1990s the building was redeveloped under a Brownfields Agreement as office and retail space in approximately 1996. The northwest adjoining properties appeared to be Hawkins Street followed by a silk mill and residential dwellings from 1929 until 1980. After 1980, the residential dwellings were redeveloped for commercial use. At the request of the client, soil-gas samples were collected to evaluate the potential for vapor intrusion into the existing structures located at 126, 128 and 130 West Worthington Avenue. Outlined below are the procedures for vapor point installation, soil-gas sample collection, and a summary of the soil-gas sampling results. Field Assessment Summary Field investigation and sampling activities were conducted on May 24 and 25, 2016, under the supervision of Mr. Bryan Lucas, Project Manager for PSI. The Soil-Gas Sampling Assessment was conducted under the direction of a qualified professional who meets the requirements of a “Phase II Assessor” under the ASTM Standard Practice E1527. Prior to the commencement of assessment activities, North Carolina 811, a utility locating service, was contacted to locate all utilities on or adjacent to the subject site. Prior to the field investigation, utilities were marked by the respective utility companies where they entered or were located adjacent to the site. Vapor Point Installation Three (3) temporary vapor points (VP-1 through VP-3) were installed on the subject property (Figure 3). Each of the soil test borings were advanced using a Geoprobe® Macro-Core® sampler. The Macro-Core® sampling apparatus consists of a two-inch inside diameter (ID) by five-foot long stainless-steel hollow rod, which is lined with a disposable transparent acetate liner. Soil samples are retained within the disposable liner, which can be removed from the sampling instrument for visual inspection and description, sample collection, and/or field screening and analysis. The sampling apparatus is capable of sampling an approximately five-foot long soil core on a single drive. Once each boring was advanced to its termination depth, a soil-vapor monitoring point was installed. The depths of the respective soil-vapor monitoring points were chosen by evaluating the encountered subsurface conditions, the interpreted groundwater depth, and the results of soil sample field screening conducted during past site assessment activities. Each of the soil-vapor points consisted of a 12-inch long by 0.25-inch diameter stainless steel screen implant with a dedicated piece of Teflon® tubing attached and terminated above ground surface. Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 4 of 7 The following is a general description of how the soil-vapor points were installed in each of the soil borings: 1. Once the soil boring was terminated, the drilling tools were removed and a 1-inch outside diameter polyvinyl chloride (PVC) tremie pipe was placed in the boring annulus. All subsequent materials used to install the vapor points were placed in the boring through the tremie pipe. 2. Approximately 6-inches of sand was placed in the bottom of the boring. 3. A 12-inch stainless steel screen with attached Teflon® tubing was installed and backfilled with sand to approximately one foot above the top of the screen. 4. Granulated bentonite/concrete mixture was placed above the sand to within 0.2-feet below existing ground surface. During the placement of the bentonite/concrete mixture, water was added several times to start the bentonite/concrete hydration process. Soil-Gas Sample Collection Each of the soil-vapor points were allowed to stabilize/seal (approximately 24-hours) prior to collecting the soil-gas samples. Prior to collecting a soil-gas sample, leak detection of the soil vapor sampling point was performed using a clear plastic shroud filled with helium gas as per NCDEQ Division of Waste Management Vapor Intrusion Assessment Guidelines (April 2014). The shroud has three ports; two on the top and one near a bottom corner. One of the ports on the top of the shroud is utilized for the tubing connected to the vapor sampling point. The other port (on top) is utilized to screen the head space under the shroud for helium concentrations during the sampling event. The port on the side of the shroud is utilized for the helium supply tubing. The shroud was placed over each of the sampling points prior to sampling. The shroud has a soft rubber gasket at point of contact with the exiting ground surface and is weighted to ensure a proper seal with the ground surface. Once the shroud was in place, the regulator on the helium cylinder was opened to create an area of inert gas under positive pressure within the shroud above the vapor point. Displaced air was allowed to vent from out of the base of the shroud while filling. A portable helium meter (Dielectric Technologies Radiodetection MGD-2002 Helium Detector) was used to purge the vapor sampling point and to detect the potential presence of helium breakthrough of the vapor point seal during purging operations. This technique provides real-time leak checking capability during the sampling event. When leaks were identified, additional measures were taken to provide a better seal at the top of the boring and at the tubing/sampler interface (e.g., add water to the existing bentonite and allow to further hydrate, while pressing down to improve the seal into the annulus of the boring). During the Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 5 of 7 sampling event, none of the vapor sampling points indicated breakthrough of helium while purging. Following purging of the vapor sampling point, the Helium meter was removed from the vapor point tubing and a 6-liter summa canister was connected with tubing via a 30-minute regulator. The influent end of the Helium meter was than inserted into the second port on the top of the shroud. Once the helium reached 30-percent by volume under the shroud, the regulator valve on the summa canister was opened. During the sample collection, PSI monitored the helium concentration under the shroud to insure levels of 30 to 25 percent of helium by volume was maintained. Each of the soil-gas samples collected were placed in a shipping container and shipped to Con-Test Laboratories in East Longmeadow, Massachusetts under strict chain of custody protocols for laboratory analysis by EPA Method TO-15. Deviations from Project Scope There were no significate deviations from the original scope-of-work for the project. Summary Soil-Gas Sampling Results The soil-gas sample results are summarized in Table 1 and the laboratory results with chain- of-custody are also appended. The soil-gas analytical results were compared to the North Carolina Department of Environmental Quality (NCDEQ) Division of Waste Management (DWM) Vapor Intrusion Screening Concentrations for Residential and Non-Residential Properties (March 2016). The laboratory reported VOCs with concentrations above laboratory method detection limits and below the NCDEQ DWM non-residential vapor intrusion screening concentrations. The laboratory reported that the following VOCs: benzene, 1,3-butadine, chloroform, ethylbenzene, trichloroethylene, 1,2,4-trimethylbenzene, and m&p xylenes had concentrations that exceeded the NCDEQ DWM residential vapor intrusion screening concentrations. Benzene, ethylbenzene and m&p xylenes were detected in soil gas samples VP-1 and VP-2. 1,3-Butadine, chloroform and trichloroethylene were detected in soil vapor sample VP-1, and 1,2,4-trimethylbenzene was detected in soil gas samples VP-1, VP-2 and VP-3. Additionally, the soil-gas analytical results indicated that the following chemicals of concern (COCs) were detected above the method detection limits (MDLs) but are below the NCDEQ DWM residential and non-residential vapor intrusion screening concentrations: acetone, 2- butanone, carbon disulfide, carbon tetrachloride, cyclohexane, dichlorodifluoromethane (Freon 12), 1,1-dichlorothylene, 4-ethyltoluene, heptane, hexane, methyl-tert-butyl ether Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 6 of 7 (MTBE), 4-methyl-2-pentanone (MIBK), naphthalene, propene, styrene, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichlorofluoromethane (Freon 11), 1,3,5-trimethylbenzene and o-xylene. The soil-gas samples were also analyzed for helium to evaluate influence from ambient air above ground. The laboratory reported that the helium concentrations in all three (3) soil gas- samples were below the laboratory reporting limit. Vapor Intrusion Discussion Vapor intrusion occurs when volatile chemicals migrate from underlying contaminated soil or groundwater into a building through cracks or openings in the floor slab or directly through the concrete to a lesser degree. Vapor intrusion occurs in response to both diffusion (chemicals migrate from areas of high concentration to low concentration) and to advection (chemicals migrate from areas of relative high pressure to lower pressure areas). Vapor intrusion into a building is directly impacted by the building construction characteristics; buildings with slab-on-grade construction with few slab cracks or penetrations and HVAC systems that maintain the building under positive pressure would experience vapor intrusion to a significantly lower degree than older buildings with basements, negative pressure HVAC systems, and significant slab cracking. Vapor intrusion potential is also related to the local geologic conditions and the depth of the contamination in relation to the slab; sites with sandy soil and a shallow groundwater table would have a higher potential for vapor intrusion than sites with deep groundwater and fine-grained relatively impermeable soils. Data Analysis and Interpretation The laboratory reported that there were 28 VOCs detected above laboratory method detection limits. Of the 28 VOCs detected by the laboratory, the following CoCs had concentrations above the NCDEQ residential vapor intrusion screening concentrations; benzene, 1,3-butadine, chloroform, ethylbenzene, trichloroethylene, 1,2,4-trimethylbenzene and m&p xylene. The laboratory reported concentrations of the detected VOCs were below the NCDEQ non-residential vapor intrusion screening concentrations. Conclusions and Recommendations PSI has conducted the methane monitoring and investigation activities at the subject site in general accordance with the contract between PSI and DCC Parcel B Plus LLC. Based on the results of this limited soil gas sampling, PSI has developed the following conclusions and recommendations: Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 7 of 7 Conclusions  Twenty-eight (28) VOCs were detected above the laboratory method detection limits.  None of the laboratory reported concentrations for the detected CoCs were above the NCDEQ non-residential vapor intrusion screening concentrations.  The laboratory reported concentrations of benzene, 1,3-butadine, chloroform, ethylbenzene, trichloroethylene, 1,2,4-trimethylbenzene and m&p xylene above the NCDEQ residential vapor intrusion screening concentrations. Recommendations Based on the proposed redevelopment of the site for commercial use, PSI recommends no further assessment of the subject property is warranted at this time. Warranty and Limitations PSI warrants that the findings contained herein have been prepared in general accordance with accepted professional practices at the time of its preparation, as applied by similar professionals in the community. Changes in the state of the art or in applicable regulations cannot be anticipated and have not been addressed in this report. This field evaluation is limited to the conditions observed and to the information available at the time of the work. The assessment and conclusions presented herein were based upon the subjective evaluation of limited data. Due to the limited nature of the work, there is a possibility that there may exist conditions which could not be identified within the scope of the assessment or which were not apparent at the time of report preparation. It is also possible that the testing methods employed at the time of the report may later be superseded by other methods. The description, type, and composition of what are commonly referred to as "hazardous materials or conditions" can also change over time. PSI does not accept responsibility for changes in the state of the art, nor for changes in the scope of various lists of hazardous materials or conditions. PSI believes that the findings and conclusions provided in this report are reasonable. However, no other warranties are implied or expressed. PSI warrants that the findings and conclusions contained herein have been promulgated in accordance with generally accepted environmental investigation methodology and only for the site described in this report. The findings set forth in this report are strictly limited to the date of the evaluation. Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 Page 8 of 7 The conclusions presented in the report are based solely on the services described herein and not on scientific tasks or procedures beyond the scope of agreed upon services. No other warranties are implied or expressed. Use By Third Parties This report was prepared pursuant to the contract PSI has with DCC Parcel B Plus LLC. That contractual relationship included an exchange of information about the subject site that was unique and between PSI and its client and serves as the basis upon which this report was prepared. Because of the importance of the communication between PSI and its client, reliance or any use of this report by anyone other than DCC Parcel B Plus LLC and Ram Development Company, for whom it was prepared, is prohibited and therefore not foreseeable to PSI. Reliance or use by any such third party without explicit authorization in the report does not make said third party a third party beneficiary to PSI’s contract with DCC Parcel B Plus LLC and Ram Development Company. Any such unauthorized reliance on or use of this report, including any of its information or conclusions, will be at third party’s risk. For the same reasons, no warranties or representations, expressed or implied in this report, are made to any such third party. Third party reliance letters may be issued on request and payment of the, then current fee for such letters. All third parties relying on PSI’s reports, by such reliance, agree to be bound by the proposal and PSI’s General Conditions. No reliance by any party is permitted without such agreement, regardless of the content of the reliance letter itself. Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 TABLE Table 1: Soil Vapor Analytical Data Summary (Detected Parameters Only) TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 Boring Location Sample ID Date Collected (m/dd/yy) Sample Depth (ft. BGS) VP-1 (128 West Worthington)VP-1 5/25/2016 6.5'-7.5'670 700 22 53J 110 1.9J 61 <1.0 3.0J 6.6 720 56 580 510 3.5J 52 12 950 2.0J 41 VP-2 (126 West Worthington)VP-2 5/25/2016 6.5'-7.5'250 330 13 20J 160 <1.5 3.6J 27.0 3.7J <0.97 420 23 320 260 <1.1 16 4.0J 620 <0.83 15 VP-3 (130 West Worthington)VP-3 5/25/2016 6'-7'240 89 <0.51 81 180 <1.5 3.4J <2.0 2.3J <0.97 150 32 120 190 39 4.9J 9.2 1,700 <0.83 3.8J 216,000 120 13.9 34,800 4,870 156 40.7 41,700 695 1,390 374 NE NE 4,870 3,600 20,900 20.9 20,900 6,950 278 2,720,000 1,570 175 438,000 61,300 2,040 533 526,000 8,760 17,500 4,910 NE NE 61,300 47,200 263,000 263 263,000 87,600 3,500 NOTES Legend BOLD Results Meet or Exceed the NCDEQ Residential Vapor Intrusion Screening Concentrations BOLD Results Meet or Exceed the NCDEQ Non-Residential Vapor Intrusion Screening Concentrations 3. NCDEQ = North Carolina Department of Environmental Qualitity BOLD Results Meet or Exceed the NCDEQ Residential and Non-Residential Vapor Intrusion Screening Concentrations 4. DWM = Division of Waste Management 4. NE = Not established 5. J = Detected but below the Reporting Limit (lowest calibration standard); therefore, result is an estimated concentration (CLP J-Flag) NCDEQ - DWM - Residential Vapor Intrusion Screen Levels for Sub Slab and Exterior Soil Screening Level (March 2016) Methyl tert-Butyl Ether (MTBE)NCDEQ - DWM - Non-Residential Vapor Intrusion Screen Levels for Sub Slab and Exterior Soil Screening Level (March 2016) Heptane2-Butanone (MEK)4-Methyl-2-pentanone (MIBK)NaphthalenePropeneStyreneTetrachloroethylene126 West Worthington Property 126, 128 and 130 West Worthington Avenue Charlotte, Mecklenburg County,North Carolina PSI Project No. 0457928 Analytical Method Dichlorodifluoromethane (Freon 12)CyclohexaneEthylbenzene4-EthyltolueneBenzeneAcetoneCarbon Tetrachloride1,3-ButadineChloroform1,1-DichlorethyleneContaminant of Concern Carbon Disulfide1. ft. BGS = feet below ground surface 2. Results reported in µg/m3 = micrograms per meter cubed Hexane Table 1: Soil Vapor Analytical Data Summary (Detected Parameters Only) 126 West Worthington Property 126, 128 and 130 West Worthington Avenue Charlotte, Mecklenburg County,North Carolina PSI Project No. 0457928 Analytical Method TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 TO-15 Boring Location Sample ID Date Collected (m/dd/yy) Sample Depth (ft BGS) VP-1 (128 West Worthington)VP-1 1,500 4.6J 19 3.3J 140 34 1,600 620 VP-2 (126 West Worthington)VP-2 1,800 <0.18 <0.30 2.8J 54 19 1,400 370 VP-3 (130 West Worthington)VP-3 1,300 <0.18 <0.30 2.2J 95 20 590 160 34,800 34,800 13.9 NE 48.7 NE 695 695 438,000 438,000 175 NE 613 NE 8,760 8,760 NOTES Legend BOLD Results Meet or Exceed the NCDEQ Residential Vapor Intrusion Screening Concentrations BOLD Results Meet or Exceed the NCDEQ Non-Residential Vapor Intrusion Screening Concentrations 3. NCDEQ = North Carolina Department of Environmental Qualitity BOLD Results Meet or Exceed the NCDEQ Residential and Non-Residential Vapor Intrusion Screening Concentrations 4. DWM = Division of Waste Management 4. NE = Not established 5. J = Detected but below the Reporting Limit (lowest calibration standard); therefore, result is an estimated concentration (CLP J-Flag) NCDEQ - DWM - Residential Vapor Intrusion Screen Levels for Sub Slab and Exterior Soil Screening Level (March 2016) Analytical Method Contaminant of Concern Toluene1,1,1-TrichloroethaneTrichloroethyleneNCDEQ - DWM - Commercial Vapor Intrusion Screen Levels for Sub Slab and Exterior Soil Screening Level (March 2016) Trichlorofluoromethane (Freon 11)1,2,4-Trimethylbenzene1. ft. BGS = feet below ground surface 2. Results reported in µg/m3 = micrograms per meter cubed 1,3,5-Trimethylbenzenem&p-Xyleneo-Xylene Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 FIGURES 126 West Worthington Site 126, 128 and 130 West Worthington Avenue Charlotte, Mecklenburg County, North Carolina PSI Project No. 0457928-1 N Approximate Scale: Site Location Map Figure 1Not to ScaleSource: USGS Charlotte East, N.C., 1967 (Photorevised 1988) Approximate Site Location N Vapor Point Location Map PSI Project No. 0457928-1 Approximate Scale:Figure 1Not to ScaleSource: Mecklenburg County GIS 2015 Commercial Building 126, 128, &130 West Worthington Ave And 1817 Hawkins Street Charlotte, Mecklenburg County, NC Approximate Property Boundary = Pole-mounted Transformer = Drop Inlet Storm Drain Storm Drain Along Building Used Oil Drum Area of Standing Water with oil Sheen 1817 Hawkins Street (1951) 124/126 West Worthington Ave (1962) 128 West Worthington Ave (1962) 130 West Worthington Ave (1966) = Vapor Point Location FIGURE-3 - TYPICAL VAPOR POINT DIAGRAM Project Number: 0457928 Date Started: Project Name:Date Completed: Location:Charlotte, North Carolina Drilling Method:Direct Push Vapor Point Length: Sampling Method:Gravel Pack Type: Ground Elevation:Grout Type/Quantity: Top of Casing:Depth to Water: Logged By:Groundwater Elevation: Remarks:Typical Vapor Point Diagram DEPTH 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 2" Groundsurface Teflon Tubing Bentonite/Concrete Seal Vapor Point Diameter: N/A N/A #2 Filter Sand 1.0-Feet 0.25-inches Page 1 of 1 0.5 5/28/2016 5/28/2016 126 West Worthington Ave N/A Continues N/A BML Stainless Vapor Point #2 Filter Sand VAPOR POINT Soil-Gas Sampling Report – Proposed DCC Mix Use Development, Charlotte, NC June 22, 2016 PSI Project Number 0457928 LABORATORY ANALYTICAL REPORT – VAPOR Page 1 of 26 Page 2 of 26 Page 3 of 26 Page 4 of 26 Page 5 of 26 Page 6 of 26 Page 7 of 26 Page 8 of 26 Page 9 of 26 Page 10 of 26 Page 11 of 26 Page 12 of 26 Page 13 of 26 Page 14 of 26 Page 15 of 26 Page 16 of 26 Page 17 of 26 Page 18 of 26 Page 19 of 26 Page 20 of 26 Page 21 of 26 Page 22 of 26 Page 23 of 26 Page 24 of 26 Page 25 of 26 Page 26 of 26