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Home My WebLink AboutWA-1382_16309_CA_LTRRPT_20230731_AFVR WithersRavenel Our People. Your Success. 115 MacKenan Drive | Cary, NC 27511 t: 919.469.3340 | f: 919.467.6008 | www.withersravenel.com | License No. F‐1479 Asheville | Cary | Charlotte | Greensboro | Lumberton | Pittsboro | Raleigh | Southern Pines | Wilmington July 31, 2023 State of North Carolina Department of Environmental Quality Federal & State Lead Program Division of Waste Management‐Underground Storage Tank Section 1646 Mail Service Center Raleigh, North Carolina 27699‐1646 Attn: Mr. Scott Ryals, P.E. Reference: Letter Report – Aggressive Fluid/Vapor Recovery Event Bell’s Service Station 8873 Highway 17 Pollocksville, Jones County, North Carolina Groundwater Incident Number: 16309 UST Number: WA‐1382 NCDEQ Contract #N70522‐C WR Project Number: 23‐0307‐AC Mr. Ryals: WithersRavenel, Inc. (WR) has prepared this Letter Report documenting the completion of an Aggressive Fluid Vapor Recovery (AFVR) event at the Bell’s Service Station in Pollocksville, Jones County, North Carolina. Activities outlined herein were completed under NCDEQ Contract # N70522‐C, Task Authorization (TA) 03 for the site, issued by NCDEQ on July 13, 2023. Aggressive Fluid Vapor Recovery Event – MW‐2R On July 25, 2023, WR personnel, along with Eastern Environmental Management, LLC (EEM) mobilized to the site and conducted an eight‐hour AFVR event. This event focused on total fluid recovery from Type II monitoring well MW‐2R. Prior to performing the AFVR event, WR personnel gauged the depth‐to‐water within wells MW‐2R and MW‐9R. Light, non‐aqueous phase liquid (LNAPL) was measured within MW‐2R, as shown in the table below. Well ID DTP DTW PT DTB MW‐2R 16.99 17.26 0.27 25 MW‐9R ‐‐‐ 19.36 ‐‐‐ 30 All Measurements shown in feet DTP = Depth to Product/LNAPL DTW = Depth to Water PT = Product/LNAPL Thickness DTB = Depth to Well Bottom WithersRavenel Our People. Your Success. Bell’s Service Station Incident # 16309 WR Project # 23‐0307‐AC Letter Report – Aggressive Fluid/Vapor Recovery Event July 2023 2 The AFVR event included application of vacuum for 8‐hours on monitoring well MW‐2R. For purposes of the recovery, the recovery “stinger” was initially placed at a depth of 17‐ft beneath the well’s top of casing (TOC) and later extended to a final depth of 22‐ft beneath TOC. Vacuum on the well ranged between 21‐ and 25‐inches (in) of mercury throughout the event. Air stream concentrations from the discharge of the blower were measured using a field calibrated RAE Systems MiniRAE 3000 Photo Ionization Detector (PID). Measured concentrations ranged from 1,156 parts per million (ppm) to 1,801 ppm. Stack temperature, velocity and relative humidity values were measured with a TSI, Inc. straight probe Model 964 thermoanemometer. At the conclusion of the AFVR, a total of 345 gallons (gal) of liquids were recovered. Emissions through volatilization of organic compounds (based on mass flow calculations) were calculated to be approximately 2.89 pounds, equating to 0.46‐gal of petroleum removed as vapor. The disposal manifest and AFVR calculations are included in Appendix A while field notes and site photographs field notes are provided in Appendix B. WithersRavenel appreciates the opportunity to be of service to the Federal & State Lead Program. Should you have any questions regarding the attached, please do not hesitate to contact WithersRavenel at (919) 469‐3340. Cordially, WithersRavenel Kevin B. Buchanan G. Matthew James, P.G. Project Manager Director of Geosciences Enclosure(s): AFVR Calculations, Field Notes, Photographs, Fluids Disposal Manifest ATTACHMENT A AFVR CALCULATIONS DISPOSAL MANIFEST AGGRESSIVE FLUID VAPOR RECOVERY EVENT SITE NAME: INCIDENT NUMBER: AVERAGE DEPTH TO GROUNDWATER: INDICATE AVERAGE HYDRAULIC CONDUCTIVITY (if known):‐ IDENTIFY THE WELL I.D. OF EACH WELL USED FOR AFVR: MW‐2R (2") TOTAL GALLONS OF PRODUCT/WATER RECOVERED IN AFVR TRUCK TANK (gallons): 345 gallons (petroleum contaminated water) DRY STANDARD CUBIC FEET PER MINUTE (DSCFM) AIR FLOW CALCULATIONS (Qstd) Date Time Vacuum Velocity Pipe ID Temp Rel Humid Water Qstd(inches of Hg) (ft/min) (in) (°F) (%/100) Vapor (Vol%) (flow) 7/25/2023 6:55 25 150 6 82.9 98.9 0 29 7/25/2023 7:00 24 139 6 85 99 0 26 7/25/2023 7:05 24.00 151 6 90 99 0 28 7/25/2023 7:10 24.00 151 6 91 99 0 28 7/25/2023 7:35 23.00 150 6 100 99 0 28 7/25/2023 7:55 23.00 150 6 100 99 0 28 7/25/2023 8:25 23.00 150 6 121 97 0 27 7/25/2023 8:55 23.00 150 6 133 96 0 26 7/25/2023 9:25 23.00 150 6 160 98 0 25 7/25/2023 9:55 23.00 150 6 160 98 0 25 7/25/2023 10:25 23.00 150 6 161 98 0 25 7/25/2023 10:55 21.00 150 6 160 98 0 25 7/25/2023 11:25 21.00 150 6 162 99 0 25 7/25/2023 11:55 21.00 150 6 165 99 0 25 7/25/2023 12:25 21.00 150 6 155 99 0 25 7/25/2023 12:55 21.00 150 6 155 99 0 25 7/25/2023 13:25 21.00 150 6 155 99 0 25 7/25/2023 13:55 21.00 150 6 165 99 0 25 7/25/2023 14:05 21.00 150 6 160 99 0 25 NOTES Qstd = Flow at DSCFM Vacuum = The level of vacuum being applied should be recorded from the vacuum truck tank (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 vacuum truck) 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)) Bell's Service Station 16309 MW‐2R: 17.26 Page 1 of 2 AGGRESSIVE FLUID VAPOR RECOVERY EVENT SITE NAME: INCIDENT NUMBER: AVERAGE DEPTH TO GROUNDWATER: INDICATE AVERAGE HYDRAULIC CONDUCTIVITY (if known):‐ IDENTIFY THE WELL I.D. OF EACH WELL USED FOR AFVR: MW‐2R (2") TOTAL GALLONS OF PRODUCT/WATER RECOVERED IN AFVR TRUCK TANK (gallons): 345 gallons (petroleum contaminated water) Bell's Service Station 16309 MW‐2R: 17.26 EMISSION CALCULATIONS Elapsed Time Flow PPMmeasured PPMwet PPMdry K PPMconc Cc:m Cc PMRc PMRg PMR (min) (DSCFM) (ppm) (#C ‐ gas)(mg/dsm3)(lb/dscf) (lb/hr) (lb/hr) (lb) 0 29 1253 1253 1253 4 5012 2501 0.00015612 0.27 0.31 0 15 26 1370 1370 1370 4 5480 2734 0.0001707 0.27 0.31 0.08 30 28 1383 1383 1383 4 5532 2760 0.00017232 0.29 0.34 0.09 45 28 1276 1276 1276 4 5104 2547 0.00015899 0.27 0.31 0.08 60 28 1192 1192 1192 4 4768 2379 0.00014852 0.25 0.29 0.07 75 28 1211 1211 1211 4 4844 2417 0.00015089 0.25 0.29 0.07 90 27 1179 1179 1179 4 4716 2353 0.0001469 0.24 0.27 0.07 105 26 1156 1156 1156 4 4624 2307 0.00014404 0.23 0.26 0.07 120 25 1181 1181 1181 4 4724 2357 0.00014715 0.22 0.26 0.06 150 25 1313 1313 1313 4 5252 2621 0.0001636 0.25 0.28 0.14 180 25 1757 1757 1757 4 7028 3507 0.00021892 0.33 0.38 0.19 210 25 1211 1211 1211 4 4844 2417 0.00015089 0.23 0.26 0.13 240 25 1440 1440 1440 4 5760 2874 0.00017942 0.27 0.31 0.16 300 25 1431 1431 1431 4 5724 2856 0.0001783 0.27 0.31 0.31 360 25 1745 1745 1745 4 6980 3483 0.00021743 0.33 0.38 0.38 420 25 1377 1377 1377 4 5508 2748 0.00017158 0.26 0.30 0.30 480 25 1470 1470 1470 4 5880 2934 0.00018316 0.28 0.32 0.32 510 25 1750 1750 1750 4 7000 3493 0.00021805 0.33 0.38 0.19 540 25 1738 1738 1738 4 6952 3469 0.00021656 0.33 0.38 0.19 Total emissions in pounds 2.89 Gallons of Gasoline Removed: =Gallons = 0.74*8.34lbs/gallon 0.462995 Gallons of Gasoline Removed as Vapor 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, Propane K = 3, Isobutylene = 4, 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 Cc = (Cc:m)(62.43x10‐9 lb‐m3/mg‐ft3) PPMdry = (PPMwet)/(1‐Bws)PMRc = (Cc)(Qstd)(60 min/hr) PPMc = (PPMd)(K) PMRg = (PMRc)(Mg/Mcg) Cc:m = (PPMc)(Mc / K3)PMR = (PMRg)(#minutes/60) Page 2 of 2 ATTACHMENT B FIELD NOTES AND SITE PHOTOGRAPHS Bell’s Service Station Incident # 16309 WR Project # 23‐0307‐AC Letter Report – Aggressive Fluid/Vapor Recovery Event July 2023 PHOTO 1 SITE CONDITIONS – JULY 25, 2023 PHOTO 2 VAC TRUCK ON SITE – JULY 25, 2023 Bell’s Service Station Incident # 16309 WR Project # 23‐0307‐AC Letter Report – Aggressive Fluid/Vapor Recovery Event July 2023 PHOTO 3 RECOVERY TRUNK SETUP PHOTO 4 MW‐2R DURING AFVR EVENT