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Home My WebLink AboutWS-27979_47268_CA_RMR_20210723_FHPProperty July 23, 2021 Raymond J. Gibbs Forward High Point, Inc. 164 S. Main Street – Suite 606 High Point, NC 27260 Reference: MMPE Groundwater Remediation FHP Property 720 N. Main Street High Point, North Carolina Groundwater Incident: 47268 Dear Mr. Gibbs: The above referenced facility owned by Forward High Point, Inc. at 720 N. Main Street, which formerly contained an auto service facility, has previously shown groundwater impact in excess of the Gross Contaminant Levels (GCLs) in monitor well MW-1. Following the completion of a Limited Site Assessment and Soil Assessment Report along with a recommendation to perform groundwater remediation, a 96-hour MMPE groundwater remediation event was conducted at the subject site during the week of June 28, 2021. Figure 1 illustrates the location of the monitor wells at this project site, and a MMPE summary report prepared by Advanced Environmental is included as Attachment A. Previous lab results for monitor well MW-1 have indicated Benzene, EDB, and 1,2-Dichloroethane at concentrations which exceed the GCLs. On July 6, 2021, which was four days after completion of the most recent MMPE event, this monitor well was resampled for analysis by EPA Method 6200B. The Benzene level had decreased to 4,960 micrograms per liter (ug/L), and both EDB and 1,2-Dichloroethane were significantly below their respective GCLs. Table 1 summarizes the laboratory analytical results for the sampling events conducted by Paragon at this subject facility. Attachment B contains copies of the laboratory reports and the chain-of-custody records for the groundwater sample from MW-1 collected before and following the recent MMPE event. Sincerely, Brandon Moore, L.G. Paragon Environmental Consultants, Inc. PARAGON Environmental Consultants, Inc. P.O. Box 157 • Thomasville, NC 27361-0157 Business Ph: (336) 669-6037 • Fax: (336) 476-7708 FIGURES TABLES TABLE 1 Summary of Groundwater Laboratory Analytical Results 720 N. Main Street High Point, NC Constituent MW-1 MW-1 MW-1 MW-1 2L Standard GCL Date 9/29/2020 4/5/2021 6/28/2021 7/6/2021 EPA Methods 602 / 6200B (ug/L) Benzene 33,500 14,000 15,100 4,960 1 5,000 Toluene 9,670 8,010 5,810 769 600 260,000 Ethylbenzene 1,590 1,280 1,360 242 600 84,500 Xylenes (total)6,600 6,020 5,160 670 500 85,500 BTEX (total)51,360 29,310 27,430 6,641 NSE NSE 2-Butanone (MEK)1,670 BDL N/A BDL 4,000 4,000,000 n-Butylbenzene BDL BDL N/A 8.8 70 6,900 2-Chlorotoluene BDL BDL N/A BDL 100 NSE 1,2-Dibromoethane (EDB)BDL 230 N/A 19.4 0.02 50 1,2-Dichloroethane 1,660 570 N/A BDL 0.4 400 1,2-Dichlorobenzene BDL BDL BDL BDL 20 20,000 cis-1,2-Dichloroethene BDL BL N/A BDL 70 70,000 Ethanol BDL BDL N/A BDL 4,000 4,000,000 Isopropylbenzene 65 BDL N/A 10.8 70 25,000 Methylene Chloride BDL BDL N/A BDL 5 5,000 Methyl Isobutyl Ketone (MIBK)187 BDL N/A BDL 100 100,000 Naphthalene 452 302 623 38.5 6 6,000 n-Propylbenzene 97 BDL N/A 14.5 70 30,000 Tetrachloroethene (PCE)BDL BDL N/A BDL 0.7 700 Trichloroethene (TCE)BDL BDL N/A BDL 3 3,000 1,2,4-Trimethylbenzene 740 580 N/A 82.8 400 28,500 1,3,5 Trimethylbenzene 233 186 N/A 24.3 400 25,000 MTBE BDL BDL BDL BDL 20 20,000 IPE 3,100 1,020 546 478 70 70,000 BDL = Below Detection Limits N/A = Not Analyzed NSE = No Standard Established X21-2065A Attachment A MMPE SUMMARY REPORT (PREPARED BY ADVANCED ENVIRONMENTAL) ADVANCED ENVIRONMENTAL SERVICES, INC. “Your Environmental Solutions Partner” MOBILE MULTI-PHASE EXTRACTION REPORT Site Location: Forward High Point Property 720 North Main Street High Point, North Carolina Prepared for: Paragon Environmental Consultants, Inc. P.O. Box 157 Thomasville, North Carolina 27361 PM – Mr. Brandon Moore, PG July 8, 2021 TABLE OF CONTENTS EVENT SUMMARY MMPE FIELD LOGS MASS-REMOVAL CALCULATION FIELD NOTES DISPOSAL MANIFEST MOBILE MULTI-PHASE EXTRACTION EVENT SUMMARY July 8, 2021 Location: Forward High Point Property 720 North Main Street High Point, North Carolina Client: Paragon Environmental Consultants, Inc. P.O. Box 157 Thomasville, North Carolina 27361 Event Dates: June 28 - July 2, 2021 Advanced Job # 06 - 2135 Advanced Personnel: Lee Heilig and Gary McDaniel MMPE System: MMPE system rated 24”hg at 140 CFM 4’ discharge stack - 2” diameter 5,000 - gallon tanker Approximately 40’of 2.0” hose to 1 well Extraction Well: MW-1 Well Initial FP/WL(ft) Final FP/WL(ft) Stinger depth(ft) Run Time MW-1 15.49/15.61 17.10 16 96.0 hours Description of Event: The MMPE event ran from 10:50 June 28, through 10:50 July 2, 2021. The MMPE system was active for 96.0 hours. During the event vacuum at the recovery pump ranged from 18.0 to 22.0 inches of mercury (hg) and stabilized at approximately 18.0 inches of mercury. Air-flow rates ranged from 2,700 to 3,500 feet per minute and stabilized at 3,500 feet per minute. System temperature ranged from 126 – 146 degrees (F) and humidity ranged from 18 to 99 percent. Field gauged volatile organic compounds (VOC’s) decreased from 72,000 parts per-million (PPM) to 32,000 (PPM) throughout the event. Groundwater / Product Mix Recovered: During the event a total of 9,110 gallons of product/water mix were removed from the site and properly disposed at a certified North Carolina disposal facility. A petroleum sheen was observed in tanker. Total fluids recovered, was measured based on stick readings conducted during and following the event. Based on 96.0 hours of operation and a total of 9,110 gallons recovered, the average groundwater recovery rate was calculated to be approximately 94.90 gallons per hour. . Events Results: Based on mass-removal calculations 689.89 pounds or 112.14 gallons of VOC’s (as gasoline) were removed as vapor. Using Dwyer Magnehelic Gauges, vacuum influence readings were taken at monitoring point MW-2. No vacuum influence was observed at any monitoring point. Drawdown was observed at MW-2 at 1.18 feet. Following the event, no free product was identified in any well. . MMPE FIELD LOG: CLIENT: Paragon Environmental JOB NAME: Forward High Point Property LOCATION: High Point, NC MMPE EVENT DATES: June 28 - July 2, 2021 EXTRACTION POINTS: MW-1 AES JOB NUMBER: 06 - 2135 DATE TIME FLOW (f/m) HUM.(%) TEMP. (F)VOC's(ppm)VAC. (hg")GALLONS STINGER/WL's EXTRACTION POINTS (hg") MW-1 Stinger(ft)16 Start 10:50 Initial WL's 15.49/15.61 06/28/21 11:00 3,000 99.0 126 70,000 21.0 18.0 12:00 3,000 87.0 130 64,000 21.0 18.0 13:00 3,000 82.0 136 60,000 21.0 18.0 16:30 3,000 73.0 142 66,000 21.0 660 gal.18.0 06/29/21 8:10 2,800 60.0 128 70,000 22.0 2700 gal.18.0 9:10 2,800 55.0 132 72,000 22.0 18.0 10:15 2,800 53.0 134 70,000 22.0 18.0 16:00 2,800 50.0 140 68,000 22.0 PO 4,005 18.0 06/30/21 8:15 3,500 43.0 136 54,000 18.0 1,020 gal.13.0 9:15 3,500 41.0 138 56,000 18.0 13.0 10:15 3,500 34.0 140 54,000 18.0 13.0 15:45 3,500 28.0 146 48,000 18.0 1,500 gal.13.0 07/01/21 8:25 3,500 23.0 136 36,000 18.0 2,640 gal 13.0 9:25 3,500 25.0 134 34,000 18.0 13.0 10:25 3,500 21.0 136 36,000 18.0 13.0 16:05 3,500 18.0 146 32,000 18.0 13.0 07/02/21 8:20 2,700 26.0 128 34,000 22.0 4,510 gal.18.0 9:45 2,800 21.0 130 32,000 22.0 18.0 PO 5,105 Final WL's 17.10 End 10:50 Total fluids: 9,110 gal. Total free product:sheen DATE TIME STINGER/WL's EXTRACTION POINT (hg) cont. VACUUM INFLUENCE (h2o") WELL GAUGING (ft) MW-2 MW-2 Start 10:50 Stinger(ft) Initial WL's 15.81 06/28/21 13:00 0.00 06/29/21 16:00 0.00 16.99 06/30/21 15:45 0.00 16.79 07/01/21 10:25 0.00 16.49 07/02/21 8:20 0.00 16.52 Final WL's End 10:50 Page 1 of 1 MOBILE MULTI-PHASE EXTRACTION EVENT SITE NAME: FORWARD HIGH POINT PROPERTY CLIENT: PARAGON ENVIRONMENTAL INCIDENT NUMBER: AVERAGE DEPTH TO GROUNDWATER: 15 - 16 ft. DESCRIBE SOIL IN THE SATURATED ZONE: AVERAGE HYDRAULIC CONDUCTIVITY (if known): EXTRACTION WELLS USED FOR MMPE: MW-1 SPECIFICATIONS OF THE MMPE SYSTEM (cfm @ in Hg): 140 cfm @ 24.0"Hg DRY STANDARD CUBIC FEET PER MINUTE (DSCFM) AIR FLOW CALCULATIONS (Qstd) Date Hours Vacuum Velocity Pipe ID Temp Rel Humid Water Water Qstd (inches of Hg)(ft/min)(in)(°F)(%)Vapor (Wt%)Vapor (Vol%)(flow) 6/28/21 24.00 21.00 3000.00 2 134 85.0 0.103 0.142 50 6/29/21 48.00 22.00 2800.00 2 133 55.0 0.061 0.089 50 6/30/21 72.00 18.00 3500.00 2 140 37.0 0.048 0.071 62 7/1/21 96.00 19.00 3250.00 2 135 22.0 0.024 0.037 61 7/2/21 NOTES Qstd = Flow at DSCFM Vacuum = The level of vacuum being applied should be recorded from the MMPE system (inches of Hg) Velocity = The rate at which air flows is measured at the blower discharge piping (anemometer or pitot tube) Pipe ID = The inside diameter of the blower discharge piping (from the MMPE system) Temperature = The temperature of the air stream exiting the blower discharge piping (dry bulb temp., in deg.°F) Relative humidity = The % relative humidity of the air stream exiting the blower discharge piping Bwsw = water vapor % by weight, i.e., pounds of water per pound of dry air, derived from the Psychrometric chart (temp Vs relative humidity) Bws = water vapor % by volume EQUATIONS Bws = (Bwsw/18 lb-mole H20)/[(1/28.84 lb-mole dry air) + (Bwsw/18 lb-mole H2O)] Qstd = (1-Water Vapor) * velocity * (PI * (diameter/24)2) * (528°R/(Temp + 460)) EMISSION CALCULATIONS Elapsed Time Flow PPMmeasured PPMwet PPMdry K PPMconc Cc:m Cc PMRc PMRg PMR (hour)(DSCFM)(ppm)(#C - gas)(mg/dsm3)(lb/dscf)(lb/hour)(lb/hour)(lb) 24 50 65000 65000 75727 1 75727 37785 0.0023589 7.07 8.18 196.31 48 50 70000 70000 76841 1 76841 38341 0.00239362 7.12 8.24 197.65 72 62 53000 53000 57076 1 57076 28479 0.00177793 6.66 7.70 184.88 96 61 34000 34000 35307 1 35307 17617 0.00109983 4.00 4.63 111.05 Total emissions in pounds 689.89 Total emissions as gallons (pounds / 6.152)112.14 NOTES PPMmeasured = Actual measurements (ppm) taken with a OVA or TVA at the blower discharge piping PPMwet = "wet" concentration PPMdry = "dry" concentration K = Number of carbons in calibration gas: (Methane K = 1, or Propane K = 3, or Hexane K = 6) PPMc= PPMv, Volumetric concentration of VOC emissions as carbon, dry basis at STP Cc:m = mg/dsm3, mass concentration of VOC emissions as carbon Mc = 12.01 mg/mg-mole, molecular weight of carbon K3 = 24.07 dsm3/106 mg-mole, mass to volume conversion factor at STP Cc = lb/dcsf, mass concentration of VOC emissions as carbon, dry basis at STP PMRc = lb/hr, pollutant mass removal rate of VOC's as carbon PMRg = lb/hr, pollutant mass removal rate of of VOC's as gasoline PMR = lb, pollutant mass removal of VOC's as gasoline EQUATIONS PPMwet = PPMmeasured PPMdry = (PPMwet)/(1-Bws) PPMc = (PPMd)(K) Cc:m = (PPMc)(Mc / K3) Cc = (Cc:m)(62.43x10-9 lb-m3/mg-ft3) PMRc = (Cc)(Qstd)(60 minute/hour) PMRg = (PMRc)(Mg/Mcg) PMR = (PMRg)(#hours) Attachment B GROUNDWATER ANALYTICAL RESULTS