The URL can be used to link to this page

Home My WebLink About17047 BF Assessment WP Premier 485 20160810 Via Email August 10, 2016 LRC Patriot, LLC c/o Womble Carlyle Sandridge & Rice, LLP One West Fourth Winston-Salem, NC 27101 Attention: Ms. Lori Hinnant Subject: Brownfields Assessment Work Plan – Undeveloped Land Premier 485 - 1700 Continental Blvd Charlotte, North Carolina Brownfields Project ID# 17047-13-60 H&H Project No. LRC-004 Dear Lori: 1.0 Introduction Per your request, Hart & Hickman, PC (H&H) is providing this work plan to conduct Brownfields assessment activities on the Premier 485 property located at 1700 Continental Boulevard in Charlotte, Mecklenburg County, North Carolina (Site or subject Site). A Site location map is included as Figure 1. The Site is comprised of one parcel identified as 1700 Continental Boulevard totaling approximately 25.93 acres and a portion of a parcel identified as 1900 Continental Boulevard that totals approximately 1.11 acres. This area is part of a larger site where a letter of eligibility has been obtained for admittance into the North Carolina Department of Environmental Quality (DEQ) Brownfields Program (Project ID#17047-13-60). The former uses of the Site include a Naval Ammunitions Depot (NAD) in the 1940s and 1950s and tire manufacturing ancillary operations in the 1960s and 1970s. Based on 1950’s era aerial photos and a 1950 map of the former NAD, numerous buildings surrounded by protective soil berms to hold live ammunition were previously located on the Site. The site is currently heavily wooded and undeveloped. Ms. Lori Hinnant August 10, 2016 Page 2 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc 2.0 Background During wetlands delineation Site reconnaissance activities conducted in September 2015, burned/melted rubber mixed in with drums containing white material and burned/melted rubber on the ground surface near the drums were observed in the southeastern portion of the Site. Also, a layer of unnatural black stained soil was observed up to a few inches deep that is widespread in the southeast portion of the Site. These materials were observed in the vicinity of a former incinerator structure. The incinerator structure does not appear on aerials until the late 1960s, which is during the time that the tire plant operated next to the Site. In November 2015, H&H conducted waste material and surface soil sampling activities at the Site. H&H identified two areas with elevated zinc concentrations and trace levels of explosive residuals. One zinc concentration exceeded the DEQ IHSB Industrial Soil Remediation Goal (SRG). To facilitate redevelopment in a timely fashion, H&H removed the discarded waste materials from February 29, 2016 to March 10, 2016. Following removal activities, one confirmatory base soil sample was collected from the excavated area beneath the highest concentration of zinc identified during the initial assessment and analyzed for Hazardous Substance List (HSL) Metals. The results of the confirmatory base sample indicated that elevated zinc was present in the soil, but the concentration was less than the DEQ IHSB Industrial SRG. Additionally, during removal of two drums located in the southeastern portion of the Site, liquid was observed in the ground where the drums were removed. The saturated soil was subsequently removed and containerized in two 55-gallon drums, and sampled for disposal purposes. Disposal sample results indicated that the soil contained characteristically hazardous levels of benzene. Due to the detected concentration of benzene, the excavated soil from this area was disposed as hazardous waste. Ms. Lori Hinnant August 10, 2016 Page 3 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc The Site is scheduled to be developed for industrial, warehouse, and light manufacturing use. The proposed Brownfields assessment activities are to evaluate soil, soil vapor, and groundwater conditions in the vicinity of the proposed development to assist in management of contaminated media during development and to evaluate the potential for vapor intrusion into the proposed building. The scope of work for the additional assessment activities is provided below. 3.0 Brownfields Assessment Scope of Work To evaluate the potential for future vapor intrusion, H&H proposes to collect eight soil samples and eight co-located soil gas samples within the proposed building footprint, and one soil sample south of the proposed building footprint where benzene was previously detected during drum removal activities. Additionally, H&H proposes to collect two upgradient groundwater samples located near the western property boundary to evaluate the potential for impacted groundwater migrating under the proposed building from known groundwater plumes to the west. The approximate locations of the proposed sample points are depicted on Figure 2. These proposed assessment activities will be performed in general accordance with DEQ’s Inactive Hazardous Sites Branch (IHSB) October 2015 Guidelines for Assessment and Cleanup and IHSB’s April 2014, Supplemental Guidelines for the Evaluation of Structural Vapor Intrusion Potential Site Assessments and Remedial Actions Under the IHSB (hereafter referred to as IHSB Guidance). The proposed assessment activities and methods have been developed to comply with IHSB Guidance and the latest version of the U.S. Environmental Protection Agency (EPA) Region IV Science and Ecosystem Support (SESD) Field Branches Quality System and Technical Procedures guidance. Where appropriate, significant deviations from the IHSB Guidance are identified in the text below. Prior to conducting field activities, H&H will contact NC One-Call, the public utility locator, to mark subsurface utilities at the site. H&H will also contract a private utility locator to mark utilities which may not be identified by the public locator. Additionally, each boring location Ms. Lori Hinnant August 10, 2016 Page 4 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc will be hand cleared to a depth of approximately 5 feet (ft) below ground surface (bgs) to further screen the boring locations for the presence of subsurface utilities. In accordance with Mecklenburg County rules, H&H will also obtain a Subsurface Investigation Permit (SIP) from Mecklenburg County prior to the temporary monitoring well installation and sampling. After completion of the activities, H&H will close out the SIP. As long as the wells are temporary, there will be no well registration fees associated with the temporary wells. While some paths were created through wooded areas across the subject Site during previous assessment and geotechnical activities, H&H will likely need to clear small diameter trees to create access paths to the proposed sample locations for drill equipment, support vehicles, and sampling instruments. Limited costs are included for preparing to access the wooded area. 3.1 Soil Assessment Activities In order to evaluate the potential for impacts in the soil, H&H proposes to advance eight soil borings within the proposed building footprint. One soil boring will also be placed in the proposed location of the stormwater pond where extensive excavation is planned. Additionally, one soil boring will be advanced south of the proposed building footprint where characteristically hazardous levels of benzene were previously detected. Proposed soil boring locations are provided on Figure 2. H&H will team with a drilling contractor to utilize a track-mounted direct push technology (DPT) drill rig to advance each boring to depths of approximately 15 ft bgs (or refusal). Continuous soil samples will be collected from each boring using acetate lined macrocore sleeves. Soil samples will be logged for lithological description and field screened for indication of potential impacts by observation for staining, and the presence of organic vapors using a photoionization detector (PID). Based upon field screening results, one soil sample will be collected from each soil boring at the interval interpreted most likely to be impacted. If there are no obvious indications of potential impact based on field screening results at a soil boring, then a Ms. Lori Hinnant August 10, 2016 Page 5 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc sample will be collected from the top two feet of the soil boring to evaluate surficial soils prior to grading activities associated with the proposed development. Following collection, the soil samples will be placed in dedicated laboratory-supplied sample containers, labeled with the sample identification, date, and requested analysis, and placed in a laboratory supplied cooler with ice. The samples will be delivered to a North Carolina certified laboratory under standard chain of custody protocols for analysis of volatile organic compounds (VOCs) by EPA Method 8260B, semi-VOCs (SVOCS) by EPA method 8270D, hazardous substance list (HSL) metals by EPA Methods 6010/6020/7470/7441, and explosives by EPA Method 8330A. Metal detections in soil will be compared to naturally occurring metal concentrations reported in the literature for North Carolina. Following sampling activities, borings will be properly abandoned and the surfaces will be repaired similar to pre-drilling conditions. Additionally, soil sample locations will be estimated using a sub-meter GPS unit. 3.2 Soil Vapor Assessment Activities H&H proposes to collect eight soil gas samples within the proposed building footprint to evaluate the potential for vapor intrusion from possible soil and/or groundwater impacts. H&H will install soil vapor monitoring points co-located with eight of the soil boring locations described above. The proposed soil gas sample locations are depicted on Figure 2. The soil gas sampling points will be installed utilizing the track-mounted DPT drill rig to advance borings to approximately 5 feet above the groundwater table in general accordance with IHSB Guidance. A six-inch stainless steel screen point fitted with ¼-inch diameter Teflon® tubing will then be installed within the borehole. Filter sand will placed from the base of the boring to 6-inches above the screened interval. The sampling points will be completed by placing hydrated bentonite from the top of the filter sand to the ground surface. Ms. Lori Hinnant August 10, 2016 Page 6 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc Prior to sampling, a leak check will be conducted at each soil gas sampling point by constructing a shroud around the sampling point and flooding the air within the shroud with helium gas. Using a syringe, a sample will be collected from the gas in the shroud into a Tedlar® bag and analyzed for helium concentrations using a helium gas detector. Vapor from the 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 10% of the concentration measured within the shroud. Following a successful field leak check, the vapor samples will be collected into six-liter Summa canisters for laboratory analysis by connecting the Teflon® sample tubing to an airflow regulator using a brass nut and ferrule assembly to create an air tight seal. The airflow regulator will be calibrated by the laboratory to allow the Summa canisters to fill slowly over a period of approximately one hour per point. Upon completion of sample collection, the air flow regulator will be removed from the Summa canister and the samples will be packaged and shipped to the laboratory for analysis of VOCs plus nitrobenzene reported as a tentatively identified compound (TIC) by EPA Method TO-15. Upon completion of sampling, the vapor monitoring points will be properly abandoned and the locations will be estimated using a sub-meter GPS unit. 3.3 Groundwater Assessment Activities H&H will install two temporary monitoring wells in the western portion of the Site using the track-mounted DPT drill rig. During drilling, continuous soil samples will be collected from each boring using acetate lined macro-core sleeves. Soil samples will be logged for lithologic description and field screened for the presence of staining and elevated organic vapor concentrations using a PID. Each temporary monitoring well will be installed to approximately Ms. Lori Hinnant August 10, 2016 Page 7 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc 25 to 30 ft bgs. For cost estimation purposes, we assume that groundwater will be encountered prior to DPT refusal. The temporary monitoring wells will be constructed of 1-inch diameter PVC with 10 to 15 ft of well screen set to bracket the water table and 1-inch diameter PVC well casing to the ground surface. Once a temporary monitoring well is installed, the well will be allowed to equilibrate to static conditions and a decontaminated electronic water level indicator will be used to measure the depth to the water table relative to the ground surface. The well will then be developed by removing a minimum of 3 to 5 well volumes and field parameters (pH ± 0.1 SU and conductivity varies no more than 5%) have stabilized. After development, groundwater samples will be collected utilizing low flow/low stress purging techniques using a peristaltic pump and dedicated polyethylene tubing. The intake point of the pump tubing will be placed in the approximate mid-portion of the screened interval of the well and groundwater will be removed at a rate no greater than 200 milliliters per minute. H&H will utilize a water quality meter to collect measurements of pH, temperature, dissolved oxygen, oxidation reduction potential, turbidity, and specific conductivity at 3-5 minute intervals during the purging process. Purging will be considered complete when the parameters stabilize (pH ± 0.1 SU and conductivity varies no more than 5%). Once groundwater parameters stabilize, groundwater samples will be collected directly into laboratory supplied sample containers using the “soda straw” method. The sample containers will be labeled with the sample identification, date, and requested analysis, and placed in a laboratory supplied cooled and iced. The samples will be delivered to a North Carolina certified laboratory under standard chain of custody protocols for analysis of VOCs by EPA Method 8260B and explosives by 8330A. Following sample collection, the monitoring wells will be properly abandoned by a licensed well driller. The groundwater sampling locations will be estimated using a sub-meter GPS unit. Ms. Lori Hinnant August 10, 2016 Page 8 S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-004 Brownfields Assessment - undeveloped parcel\BF Work Plan\BF Assessment WP Premier 485.doc 3.4 Investigation Derived Waste Investigation derived waste (IDW) generated during the assessment activities will be thin spread on-Site. However, if significant impacts are suspected, the soil cuttings and/or purge water will be containerized in 55-gallon drums and staged on-Site pending analytical results of a composite IDW sample. Costs for laboratory analysis, transport, and disposal of IDW have not been included in this proposal. 3.5 Reporting Following completion of the assessment activities and receipt of the analytical data, H&H will document our findings in a Brownfields Assessment report. The report will include a description of the sampling activities, a figure depicting sample locations, soil boring logs, a discussion of the data in comparison to regulatory screening levels, laboratory analytical data, and conclusions and recommendations concerning our activities. We appreciate the opportunity to assist with this project. Should you have any questions or need additional information please do not hesitate to call us at (704) 586-0007. Sincerely, Hart & Hickman, PC Ralph McGee, PG Matt Bramblett, PE Project Geologist Principal Attachments SITE 0 2000 4000 APPROXIMATE SCALE IN FEET N U.S.G.S. QUADRANGLE MAP QUADRANGLE 7.5 MINUTE SERIES (TOPOGRAPHIC) Charlotte West, North Carolina 1996 TITLE PROJECT SITE LOCATION MAP PATRIOT SITECONTINENTAL BOULEVARDCHARLOTTE, NORTH CAROLINA DATE: JOB NO: REVISION NO: FIGURE: 04-06-16 0 1LRC-001 LEGEND SITE PROPERTY BOUNDARY RAILROAD SPURS PERENNIAL STREAM INTERMITTENT STREAM EPHEMERAL STREAM PROPOSED STORMWATER MANAGEMENT POND PROPOSED BUILDING FOOTPRINT PROPOSED SOIL SAMPLE LOCATION PROPOSED SOIL GAS SAMPLE LOCATION PROPOSED GROUNDWATER SAMPLE LOCATION 2923 South Tryon Street-Suite 100 Charlotte, North Carolina 28203 704-586-0007(p) 704-586-0373(f) License # C-1269 / #C-245 Geology JOB NO. LRC-001 REVISION NO. 0DATE: 4-6-16 FIGURE NO. 2 PATRIOT SITE CONTINENTAL BOULEVARD CHARLOTTE, NORTH CAROLINA PROPOSED SAMPLE LOCATION MAPCONTINENTAL BOULEVARDNOTES: 1.ALL FEATURES ARE APPROXIMATE IN LOCATION & SIZE. 2.AERIAL IMAGERY OBTAINED FROM GOOGLE EARTH (2015).S:\AAA-Master Projects\LRC Patriot (LRC)\LRC-001 Continental Wetlands\Figures\Proposed Sample Location Map.dwg, FIG 2, 4/8/2016 9:55:33 AM, zbarlow