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Home My WebLink AboutWS-9069_44302_CA_CSA_20150820_CSA-NotApproved Progress Environmental, Inc. P.O. Box 5884 Winston-Salem, North Carolina 27113 Phone (336) 722-9999 Fax (336) 722-9998 TABLE OF CONTENTS A SITE IDENTIFICATION..............................................................................................................1 B SITE HISTORY AND SOURCE CHARACTERIZATION.....................................................1 1. UST CLOSURE REPORT......................................................................................................2 2. LIMITED SITE ASSESSMENT...............................................................................................3 3. OTHER SITE ACTIVITIES ....................................................................................................3 C RECEPTOR INFORMATION.....................................................................................................4 WATER-SUPPLY WELLS................................................................................................................4 PUBLIC WATER SUPPLIES .............................................................................................................4 SURFACE WATER...........................................................................................................................4 WELLHEAD PROTECTION AREAS .................................................................................................4 DEEP AQUIFERS IN THE COASTAL PLAIN PHYSIOGRAPHIC REGION.........................................4 SUBSURFACE STRUCTURES ...........................................................................................................4 PROPERTY OWNERS AND OCCUPANTS.........................................................................................4 D REGIONAL GEOLOGY AND HYDROGEOLOGY...............................................................4 E SITE GEOLOGY AND HYDROGEOLOGY............................................................................5 F SOIL SAMPLING RESULTS.......................................................................................................5 G MONITORING WELL INSTALLATION AND GROUNDWATER SAMPLING RESULTS................................................................................................................................................5 H FREE PRODUCT INVESTIGATION/RECOVERY................................................................6 I HYDROGEOLOGIC INVESTIGATION...................................................................................6 ESTIMATING AQUIFER PARAMETERS ..........................................................................................7 J GROUNDWATER MODELING RESULTS..............................................................................8 K DISCUSSION..................................................................................................................................8 L CONCLUSIONS AND RECOMMENDATIONS......................................................................8 Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 2 B Site History and Source Characterization The site is located at 8035 Cherry Grove Road in Reidsville, Caswell County, North Carolina (Figures 1 and 2). The site consists of a convenience store which stores petroleum products in underground storage tanks (USTs) and aboveground storage tanks (ASTs) for retail sale. Formerly kerosene and diesel fuel were stored in USTs. The kerosene and diesel fuel USTs were removed following the discovery of a release in 2014. Three active USTs are present at the site and used to store gasoline. The site is located in a commercial and residential area of rural Caswell County. The surrounding properties are served by water-supply wells within 1,500 feet of the source area. Progress previously completed an Initial Abatement Action Report, dated July 24, 2014; a Phase II Limited Site Assessment (LSA), dated November 26, 2014; a Free Product Recovery and Water-Supply Sampling Report dated May 8, 2015; and, a Water-Supply Well Sampling Report, dated July 31, 2015. The NCDENR issued a Notice of Regulatory Requirements (NORR), dated December 4, 2014, requiring that a Comprehensive Site Assessment (CSA) be completed for the site. Following discussions with the NCDENR, it was determined that prior to completing a CSA, free product recovery activities were to be performed and the nearby water-supply wells sampled. A description of the former UST systems is listed in Table B-1 below. Figure 2 depicts the site and the location of the monitoring wells. Table B-1 Site History, UST/AST System Information Tank No. Installation Date Capacity (gallons) Construction Materials Dimensions (inches) Removal Date Contents Previous Contents 1 4/30/1989 6,000 Steel 63” x 216” Present Gasoline Gasoline 2 4/30/1989 8,000 Steel 63” x 216” Present Gasoline Gasoline 3 4/30/1989 4,000 Steel 63” x 216” Present Gasoline Gasoline 4 4/30/1989 2,000 Steel (STP-3) 64” x 12’ 6/16/14 Diesel Diesel 5 4/30/1989 1,000 Steel (STP-3) 64” x 6’ 6/16/14 Kerosene Kerosene 6 2014 (AST) 500 Kerosene Kerosene 7 2014 (AST) 1,500 Steel 64” x 12’ Present Diesel Diesel 8 Unknown 2,000 Steel Unknown 1989 Gasoline Gasoline 9 Unknown 2,000 Steel Unknown 1989 Gasoline Gasoline 10 Unknown 1,000 Steel Unknown 1989 Gasoline Gasoline Table B-2 Site History, UST Owner/Operator Information Owner’s Name Address Phone Number Dates of Ownership Eden Oil Company, Inc. P.O. Box 1375 Reidsville, NC 27323 (336) 349-8228 1989-Present PREVIOUS INVESTIGATIONS 1. UST Closure Report Progress prepared an Initial Abatement Action Report, dated July 24, 2014. The closure activities included the removal of one 1,000-gallon kerosene UST and one 2,000-gallon diesel fuel UST. Impacted soil was noted beneath the USTs and approximately 97.76 tons of impacted soil were removed. Following the excavation of the contaminated soil, Progress collected soil samples (N-1, E-1, S-1, W-1, and B-1) from the Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 3 sidewalls and base of the excavation. The over-excavation activities were limited due to the presence of the building to the south of the excavation and the physical limits of the trackhoe. Laboratory analysis of risk- based soil samples S-1 and B-1 detected targeted compounds above their respective Soil-to-Groundwater Maximum Soil Contaminant Concentrations (MSCCs). The concentration of C9-C18 Aliphatics detected in soil sample S-1 exceeded its Residential Soil Cleanup Level. 2. Limited Site Assessment Based on the results of the soil and groundwater sampling completed during the initial abatement activities, Progress completed a Phase II LSA Report, dated November 26, 2014. Permanent monitoring wells (MW-1 through MW-4) were installed during the LSA activities. Laboratory analysis of the groundwater samples collected from monitoring wells MW-2 through MW-4 did not detect targeted compounds above their respective North Carolina 2L Groundwater Quality Standards (NC2LGWQS). Approximately 0.69 feet of free product was detected in monitoring well MW-1 on November 11, 2014. Twenty-two water-supply wells within 1,000 feet were identified during the LSA, each of which is used as a drinking water source for their respective properties. 3. Other Site Activities Progress completed a Free Product Recovery and Water-Supply Well Sampling Report, dated May 8, 2015. Progress completed a free product recovery event using mobile multi-phase extraction (MMPE) from March 9 to March 13, 2015. Free product and groundwater were extracted from monitoring well MW-1. The event extracted approximately 1,883 gallons of impacted groundwater and 96.060 pounds or 15.36 gallons of product as vapor. On April 13, 2015 Progress returned to the site to sample the existing monitoring well MW-1 or gauge free product thickness in the monitoring well, as appropriate. Approximately 1.71 feet of free product was detected in monitoring well MW-1; therefore, a groundwater sample was not collected. Progress also collected groundwater samples from water-supply wells WSW-5, WSW-7, WSW-12, WSW-14, WSW-15, WSW-20, and WSW-22 (Figure 4). Water- supply wells WSW-1 and WSW-21 are no longer in use. A groundwater sample from water-supply well WSW-6 was submitted to the laboratory; however, due to a power outage during the analysis of the sample it could not be analyzed and the sample could not be re-analyzed based on the low remaining sample volume. Laboratory analysis of the groundwater sample collected from water-supply wells WSW-5, WSW-7, WSW-12, WSW-15, WSW-20, and WSW-22 did not detect targeted compounds above the laboratory detection limits. Laboratory analysis of the groundwater sample collected from WSW-14 detected benzene (21.7 µg/L) and total xylenes (31.6 µg/L). The concentration of benzene exceeds its NC2LGWQS of 1 µg/L and the EPA Drinking Water Standard of 5 µg/L. Progress completed a Water-Supply Well Sampling Report, dated July 31, 2015. On July 6, 2015 Progress returned to the site to sample the surrounding water-supply wells and gauge groundwater/free product levels in monitoring well MW-1, as appropriate. Approximately 5.10 feet of free product was detected in monitoring well MW-1. Progress collected groundwater samples from water-supply wells WSW-2, WSW-3, WSW-5, WSW-6, WSW-7, WSW-9, WSW-10, WSW-12, WSW-13, WSW-14, WSW-15, WSW-16, WSW-17, WSW-20, WSW-22, WSW-23, and WSW-24 (Figure 3). Water-supply wells WSW-4, WSW-8, and WSW-21 are no longer in use. Laboratory analysis of the groundwater samples collected from water-supply wells WSW-2, WSW-3, WSW-5, WSW-6, WSW-7, WSW-9, WSW-10, WSW-12, WSW-13, WSW-14, WSW-15, WSW-16, WSW-17, WSW-20, WSW-22, WSW-23, and WSW-24 did not detect targeted compounds above the laboratory detection limits. Laboratory analysis of the groundwater sample collected from WSW-14 detected benzene (143 µg/L), total xylenes (225 µg/L), and naphthalene (17.0 µg/L). The concentrations of benzene and naphthalene exceed their Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 4 respective NC2LGWQS of 1 µg/L and 6 µg/L, respectively. In addition, the concentration of benzene exceeds the EPA Drinking Water Standard of 5 µg/L. C RECEPTOR INFORMATION Water-Supply Wells Twenty-two water-supply wells were identified within approximately 1,000 feet of the subject site. It is Progress’ understanding that municipal water is not available in the vicinity of the site; therefore, each nearby residence or business utilizes a water-supply well. Based on information provided to Progress, some of the residence share water-supply wells. Because municipal water is not available in the vicinity of the site, Progress did not mail water-supply well information requests to the residences. Table B-5 and Figure 4 summarize the water-supply well information. Public Water Supplies Are public water supplies available within 1,500 feet of the source are of the release? NO If yes, where is the location of the nearest public water line and the source(s) of the public water supply? Surface Water An unnamed pond is located approximately 1,350 feet to the southwest of the source area. (See Figure 1). Wellhead Protection Areas The source area is not located within an established wellhead protection area. Deep Aquifers in the Coastal Plain Physiographic Region The subject site is not located in the Coastal Plain Physiographic Province. Subsurface Structures Overhead electrical and phone utility lines service the subject site. Subsurface power and product lines are also at the site in the vicinity of the active gasoline UST system. Additional subsurface utilities are located within the rights-of-way for Cherry Grove Road and Pagetown Road. Property Owners and Occupants Ms. Inez Saunders Wrenn currently owns the subject property. Adjacent properties are developed with residential and commercial properties. The names and mailing addresses of the surrounding property owners are included in Table B-6 and the associated property boundaries are depicted on Figure 9. D REGIONAL GEOLOGY AND HYDROGEOLOGY According to the Geologic Map of North Carolina, the subject site is located in the Carolina Stale Belt of North Carolina. The rocks beneath the site have been characterized as metamorphosed granitic rocks. Groundwater generally is stored in the pore space between individual grains of residual soil and in the Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 5 fractures within the underlying parent rock. Due to the intense shearing associated with the thrust faulting in the area and the relatively shallow depths to bedrock, it can be expected that the fractures play a major role in the flow of groundwater in the subsurface. Recharge to the water table is primarily by precipitation infiltrating the upper soils and percolating downward, under the influence of gravity, to the groundwater table. Typically, the water table is not a level surface, but a subdued reflection of the land surface. However, the depth to the water table is not constant, and depends on many factors, which include the amount of rainfall, the permeability of the soil, and the amount of groundwater being pumped in the area. E SITE GEOLOGY AND HYDROGEOLOGY Based on our review of the topographic map and on-site observation, the site is located on an east-west trending ridge. Groundwater generally flows in directions sub-parallel to the ground surface slopes and under the influence of gravity toward points of discharge such as creeks, swamps, drainage swales, or pumped groundwater wells. Based on topographic inference, groundwater beneath the site most likely flows to the southeast toward an intermittent tributary of Stony Creek (Figure 1). Determination of Groundwater Flow Direction The depth to the groundwater surface in each of the monitoring wells was measured prior to well purging using a decontaminated electric sounder. The top of casings of each of the monitoring wells were surveyed by Progress using a relative benchmark (top of casing for monitoring well MW-3) that was arbitrarily given an elevation of 100 feet. The elevations of the monitoring wells and the groundwater surface are both relative to that benchmark. The relative groundwater elevations are shown on Table B-7. Groundwater elevation data were collected during the CSA activities. Relative groundwater elevations are depicted on Figure 3. Based on information collected during the CSA field activities, the groundwater flow direction beneath the site appears to be generally to the south-southwest. As presented in detail in Section I, the hydraulic conductivity was calculated as 0.70 ft/day and the groundwater flow velocity was calculated as 0.56 ft/day. F SOIL SAMPLING RESULTS Progress did not collect soil samples for vertical or horizontal delineation purposes during the Phase II LSA or CSA due to the depth to groundwater being measured at approximately one foot below the base of the previous excavation. In addition, the sidewall soil samples from the initial abatement activities were below the respective Soil-to-Groundwater MSCCs, with the exception of soil sample S-1, which is located adjacent to the on-site structure. The remaining soil impacted above the Soil-to-Groundwater MSCCs appears to be located in the “smear zone” or in close proximity and/or beneath on-site building and is not accessible based on current site conditions. G MONITORING WELL INSTALLATION AND GROUNDWATER SAMPLING RESULTS Two additional Type II permanent monitoring wells (MW-5 and MW-6, Figure 6) were installed during the CSA activities using a truck-mounted drill rig and hollow-stem augers on July 23, 2015 by SAEDACCO. Monitoring wells MW-5 and MW-6 were installed at the request of the NCDENR to Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 6 determine whether the detected petroleum-related compounds in a groundwater sample collected from water-supply well WSW-14 were the result of a release from the gasoline UST system. One Type III permanent monitoring well (DW-1) was installed using the air-rotary drilling method on July 22 and 23, 2015 in an effort to vertically delineate the extent of impacted groundwater. Well construction information is provided in Table B-7. The Non-Residential Well Construction Records, which include boring logs, are included in Appendix A. Progress returned to the site on August 3, 2015 to collect groundwater samples from monitoring wells MW-1 through MW-6 and DW-1. Monitoring well MW-1 was not sampled due to the presence of approximately 5.51 feet of free product. The groundwater samples were decanted into laboratory- supplied bottles and placed into a cooler packed with ice. The cooler was delivered under chain-of- custody to Research and Analytical Laboratories, Inc. (R&A) in Kernersville, North Carolina for testing. R&A analyzed the groundwater samples for volatile organic compounds (VOCs) by EPA Method 602 and for semi-volatile organic compounds (SVOCs) using EPA Method 625BNA plus ten tentatively identified compounds (TICs). Groundwater samples collected from monitoring wells MW-5, MW-6, and DW-1 were also analyzed for volatile and extractable petroleum hydrocarbons (VPH and EPH) by the Massachusetts Department of Environmental Protection (MADEP) Methods. A summary of the groundwater sample analytical results is included in Table B-4. The groundwater samples were collected using the methods described in Appendix B. Laboratory analysis of the groundwater samples collected from monitoring wells MW-3, MW-4, and DW-1 did not detect targeted compounds above their NC2LGWQS. Laboratory analysis of the groundwater samples collected from monitoring wells MW-2, MW-5, and MW-6 detected targeted compounds above their respective NC2LGWQS. The concentration of benzene detected in monitoring well MW-5 exceeds its Gross Contamination Level (GCL). The laboratory analytical report for the groundwater samples is provided in Appendix C. Prior to sampling, the wells were developed until the development water ran relatively clear, and the well was purged of an additional three casing volumes of water prior to sampling. The depth to the groundwater surface in each of the wells was measured prior to well purging using a decontaminated electric sounder. The wells were surveyed by Progress using a relative benchmark that was arbitrarily given an elevation of 100 feet (top of casing of monitoring well MW-3). The elevations of the monitoring wells and the groundwater surface are both relative to that benchmark. The relative groundwater elevations are shown in Table B-7. The relative groundwater elevations are depicted on Figure 3. Based on information collected during the CSA field activities, the groundwater flow direction appears to be generally to the south-southwest beneath the site. Well construction information is provided in Table B-7. The Non-Residential Well Construction Records, which include boring logs, are included in Appendix A. The laboratory test results are summarized in Table B-4 and on Figure 5. Maps depicting the plume of impacted groundwater and benzene, BTEX, and MTBE concentrations are included on Figures 6 through 8, respectively. H FREE PRODUCT INVESTIGATION/RECOVERY Approximately 0.69 feet of free product were measured in monitoring well MW-1 during the LSA sampling event on November 11, 2014. Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 7 On March 9, 2015, Progress gauged free product in monitoring well MW-1 prior to the MMPE event. Approximately 2.92 feet of free product were measured in monitoring well MW-1. On April 13, 2015 Progress returned to the site to sample the surrounding water-supply wells and gauge groundwater/free product levels in monitoring well MW-1, as appropriate. Approximately 1.71 feet of free product were measured in monitoring well MW-1. Approximately 5.10 feet of free product were measured in monitoring well MW-1 during a water-supply well sampling event on July 6, 2015. Approximately 5.55 feet of free product were measured in monitoring well MW-1 during the CSA sampling event on August 3, 2015. I HYDROGEOLOGIC INVESTIGATION Progress conducted single-well groundwater recovery tests (slug tests) in monitoring wells MW-2 and MW- 4 to develop hydraulic conductivity estimates for the surficial aquifer. Each recovery test involved quickly removing water from the well by bailing and measuring the rate of groundwater recovery using a water level sounder. The recovery test data measures the productive capacity of each well and allows estimation of the hydraulic conductivity and transmissivity of the surrounding aquifer. Progress conducted the recovery tests on August 3, 2015. The recovery tests were terminated when the water-level reached approximately 90 percent of the initial static water level measured prior to bailing or when sufficient time had elapsed. Estimating Aquifer Parameters The results of the recovery tests were used to calculate an average hydraulic conductivity for the surficial aquifer of approximately 0.70 ft/day. The Hvorslev Slug Test Method was utilized to develop hydraulic conductivity estimates. The recovery test data and calculations are presented in Appendix D. The average linear groundwater flow velocity was calculated based on the measured water table gradient (0.024 ft/ft, gradient presented from potentiometric map in the CSA), an average hydraulic conductivity of 0.70 ft/day, and an estimated value of 0.30 for effective porosity. The average linear groundwater flow velocity (v) was calculated according to the following equation: v = (K dh/dl)/ne , where K = Hydraulic Conductivity dh/dl = Hydraulic gradient ne = effective porosity Based upon this calculation, the average linear velocity of groundwater is expected to be approximately 0.056 ft/day or 20.44 feet/year. It is important to note that the assumed value for effective porosity is an estimate based on predominant soil types encountered during construction of monitoring wells at the site. It should also be noted that the calculated velocity is an approximate average for the surficial aquifer in the vicinity of the former UST system. Based on interpretation of the topographic maps and on-site observations, surface runoff at the site would be expected to flow overland following topography to the north towards a stormwater feature located within Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 8 the Cherry Grove Road right-of-way. Based on the surface topography inferred from topographic maps, properties generally to the east and northeast would be considered upgradient of the site. Based on the groundwater flow direction calculations, groundwater beneath the site appears to flow generally to the south-southwest. J GROUNDWATER MODELING RESULTS Groundwater modeling was not completed since a surface water feature is not located within 500 feet of the site. K DISCUSSION 1. NCDENR has classified the site as “high risk” based on the presence of numerous water- supply wells used for drinking water within 1,000 feet of the site. Municipal water is not available in the vicinity of the site. 2. Based on review of the laboratory data from the previous assessment activities, soil impacted above the Soil-to-Groundwater MSCCs has been removed to the extent practical. 3. Laboratory analysis of the groundwater samples collected from monitoring wells MW-3, MW-4, and DW-1 did not detect targeted compounds above their respective NC2LGWQS. Laboratory analysis of the groundwater samples collected from monitoring wells MW-2, MW-5, and MW-6 detected targeted compounds above their respective NC2LGWQS. The concentration of benzene detected in the groundwater sample collected from monitoring well MW-5 in excess of its GCL. 4. Free product has been detected and remains in monitoring well MW-1. 5. One free product recovery event via MMPE has been completed at the site. L CONCLUSIONS AND RECOMMENDATIONS Based on the findings of this CSA, Progress makes the following conclusions and recommendations: • Groundwater flow beneath the site appears to be flowing south-southwest; • Soil impacted above the Soil-to-Groundwater MSCCs appears to be located in the “smear zone” or in close proximity and/or beneath on-site building and is not accessible based on current site conditions; • Groundwater contamination in excess of the NC2LGWQS persists in on-site monitoring wells MW-2, MW-5, and MW-6. Benzene was detected in the groundwater sample collected from monitoring well MW-5 exceeds its GCL; • Free product has been measured in monitoring well MW-1. A free product thickness of 5.55 feet was measured in August 2015, at the time of groundwater sampling for the preparation of the CSA. The free product thickness appears to be increasing since the installation of monitoring well MW-1; Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 9 • Based on the calculated groundwater flow direction and the concentrations detected in groundwater samples collected from monitoring wells MW-2 and MW-5 it appears that an off- site, undocumented release of petroleum may have occurred to the north-northeast of the site; • The release related to the kerosene UST appears to have been adequately defined; • Because public water is not available in the vicinity of the site, free product recovery and groundwater remediation will be required in an effort to decrease the concentrations of petroleum-related compounds in the groundwater to below their respective NC2LGWQS; • Prior to a real estate transaction occurring, a Notice of Residual Petroleum (NORP) must be filed with the Caswell County Register of Deeds. Written permission would be required from the current property owner prior to Progress filing a NORP on the subject site. Progress recommends that the current property owner be notified of the findings of this assessment and that a copy of this report be submitted to the NCDENR; • Prepare and submit a Corrective Action Plan to address the continued free product and dissolved phase petroleum groundwater contamination; and, • Provide a copy of this report to the property owner. M FIGURES Figure 1 Topographic Site Map Pagetown Exxon 8035 Cherry Grove Road Reidsville, Caswell County, North Carolina P.O. Box 5884 Winston-Salem, NC 27113 Telephone: (336) 722-9999 Fax: (336) 722-9998 www.progressenvironmental.com United States Department of the Interior USGS 7.5 Minute Series Topographic Map Contour Interval: 10 feet Scale: 1”=2000’ Cherry Grove, North Carolina Date: 1997 Project: Pagetown Exxon Client: Eden Oil Company Progress Job #: 1015059.003 Date: August 2015 SITE Site REV0DRAWING TITLEDRAWING NUMBERFIGURE 2LEGENDApproximate MonitoringWell LocationProduct DispenserSite PlanPagetown Exxon8035 Cherry Grove RoadReidsville, North CarolinaDR.: JABAUG 15 CK.:APP'D.:SCALE: SHOWNPROGRESS NO.: 1015059.003Approximate SubsurfaceUtility LocationApproximate UST LocationDIESELApproximate Water-Supply Well LocationApproximate AST Locationwww.progressenvironmental.comP.O. Box 5884Winston-Salem, North Carolina 27113(336) 722-9999Progress Environmental, Inc.NEWMW-1MW-4MW-3MW-2MW-4MW-5MW-6Approximate R-O-WDW-1GASGASGASK-1/DiesDIESELK-1K-1/Dies REV0DRAWING TITLEDRAWING NUMBERFIGURE 3LEGENDPotentiometric MapPagetown Exxon8035 Cherry Grove RoadReidsville, North CarolinaDR.: JABAUG 15 CK.:APP'D.:SCALE: SHOWNPROGRESS NO.: 1015059.003Approximate SubsurfaceUtility LocationDispenser CanopyPlease note: MW-1 was not used in the calculation due to the presence of free product.Groundwater Contour and ElevationCalculated Groundwater Flow DirectionContour Interval = 0.70 feetInferred Groundwater Contour ElevationApproximate R-O-WApproximate Monitoring Well Locationand Groundwater Elevationwww.progressenvironmental.comP.O. Box 5884Winston-Salem, North Carolina 27113(336) 722-9999Progress Environmental, Inc.NEWMW-1MW-4MW-3MW-2MW-5MW-676.00(76.45)(77.00)(77.37)(78.67)(77.76)MW-4(76.45)77.3078.0076.60 ProgressENVIRONMENTAL, INC.JSL1015059.003AUG 2015JABAS SHOWNAUG 2015 Figure 2.SKFP.O. Box 5884WINSTON-SALEM, NORTH CAROLINA 27113PHONE 336.722.9999 FAX 336.722.9998FIGURE 4WATER-SUPPLY WELL LOCATION MAP8035 CHERRRY GROVE ROADREIDSVILLE, NORTH CAROLINAPROJECTAPPROXIMATE OBSERVED WATER-SUPPLY WELL LOCATION PLEASE NOTE: BASED ON MUNICIPAL WATER NOT BEING PRESENT IN THE VICNITY OF THE SITE,EACH RESIDENCE OR BUSINESS IS CONSIDERED TO UTILIZE A WATER-SUPPLY WELL FOR ITS SOURCE OF DRINKING WATER. THE OWNER INFORMATION IS PROVIDED IN TABLE B-5 AS OBTAINED FROM THE CASWELL COUNTY GIS. 18 19 1 23 22 5 6 7 9 10 11 1 213 14 15 16 17 202324 18 19 REV0DRAWING TITLEDRAWING NUMBERFIGURE 5LEGENDGroundwater Analytical Results Map 8/3/15Pagetown Exxon8035 Cherry Grove RoadReidsville, North CarolinaDR.: JABAUG 15 CK.:APP'D.:SCALE: SHOWNPROGRESS NO.: 1015059.003Approximate SubsurfaceUtility LocationDispenser CanopyProduct DispenserApproximate R-O-WApproximate Monitoring Well Locationwww.progressenvironmental.comP.O. Box 5884Winston-Salem, North Carolina 27113(336) 722-9999Progress Environmental, Inc.NEWMW-1MW-4MW-3MW-2MW-5MW-6MW-2Benzene 33.3 ppbEthylbenzene 90.6 ppbToluene 292 ppbTotal Xylenes 1,120 ppb2-Methylnaphthalene 17.8 ppb1-Methylnaphthalene 17.6 ppbNaphthalene 39.7 ppbBenzene 6,610 ppbEthylbenzene 4,970 ppbToluene 54,800 ppbTotal Xylenes 44,900 ppbMTBE 11,600 ppbIPE 1,580 ppb2-Methylnaphthalene 132 ppb1-Methylnaphthalene 67.6 ppbNaphthalene 621 ppbC5-C8 Aliphatics 79,700 ppbC9-C18 Aliphatics 68,730 ppbC9-C22 Aliphatics 62,049 ppbEthylbenzene 1.14 ppbToluene 1.31 ppbTotal Xylenes 13.1 ppbToluene 26.9 ppbTotal Xylenes 6.83 ppbC5-C8 Aliphatics 183 ppbC9-C18 Aliphatics 260 ppbC9-C22 Aliphatics 260 ppbBelow Quantitation LimitsFree ProductDW-1Total Xylenes 2.66 ppbC9-C22 Aromatics 132 ppb REV0DRAWING TITLEDRAWING NUMBERFIGURE 6LEGENDBenzene Isopleth MapPagetown Exxon8035 Cherry Grove RoadReidsville, North CarolinaDR.: JABAUG 15 CK.:APP'D.:SCALE: SHOWNPROGRESS NO.: 1015059.003Approximate SubsurfaceUtility LocationDispenser CanopyProduct DispenserBenzene Isopleth and Concentration (ppb)Inferred IsoplethApproximate R-O-WApproximate Monitoring Well Locationand Benzene ConcentrationPlease note: MW-1 was not used in the calculation due to the presence of free product. DW-1 was not used in the calculation because it is a Type III monitoring well.www.progressenvironmental.comP.O. Box 5884Winston-Salem, North Carolina 27113(336) 722-9999Progress Environmental, Inc.NEWMW-1MW-4MW-3MW-2MW-5MW-65,000(BQL)(BQL)(6,610)(33.3)(BQL)MW-2(33.3)5,000(FP)1,000BQLDW-1(BQL) REV0DRAWING TITLEDRAWING NUMBERFIGURE 7LEGENDBTEX Isopleth MapPagetown Exxon8035 Cherry Grove RoadReidsville, North CarolinaDR.: JABAUG 15 CK.:APP'D.:SCALE: SHOWNPROGRESS NO.: 1015059.003Approximate SubsurfaceUtility LocationDispenser CanopyProduct DispenserPlease note: MW-1 was not used in thecalculation due to the presence of free product. DW-1 was not used in the calculation because it is a Type III monitoring well.BTEX Isopleth and Concentration (ppb)Inferred IsoplethApproximate R-O-WApproximate Monitoring Well Locationand BTEX Concentrationwww.progressenvironmental.comP.O. Box 5884Winston-Salem, North Carolina 27113(336) 722-9999Progress Environmental, Inc.NEWMW-1MW-4MW-3MW-2MW-5MW-65,000(15.55)(9.52)(111,280)(1,535.90)(BQL)MW-4(15.55)50,000(FP)10,000BQLDW-1(2.66) REV0DRAWING TITLEDRAWING NUMBERFIGURE 8LEGENDMTBE Isopleth MapPagetown Exxon8035 Cherry Grove RoadReidsville, North CarolinaDR.: JABAUG 15 CK.:APP'D.:SCALE: SHOWNPROGRESS NO.: 1015059.003Approximate SubsurfaceUtility LocationDispenser CanopyProduct DispenserPlease note: MW-1 was not used in the calculation due to the presence of free product. DW-1 was not used in the calculation becasue it is a Type III monitoring well.MTBE Isopleth and Concentration (ppb)Inferred IsoplethApproximate R-O-WApproximate Monitoring Well Locationand MTBE Concentrationwww.progressenvironmental.comP.O. Box 5884Winston-Salem, North Carolina 27113(336) 722-9999Progress Environmental, Inc.NEWMW-1MW-4MW-3MW-2MW-5MW-65,000(BQL)(BQL)(11,600)(BQL)(BQL)MW-5(11,600)10,000(FP)1,000BQLDW-1(BQL) Progress N TABLES Well IDDate Collected (m/dd/yy)Depth to Water (Ft. Below TOC)11/11/2014 FP (0.69') FP FP FP FP FP FP FP FP FP FP FP FP FP FP4/13/2015 FP (1.71') FP FP FP FP FP FP FP FP FP FP FP FP FP FP7/6/2015 FP (5.10') FP FP FP FP FP FP FP FP FP FP FP FP FP FP8/3/2015 FP (5.55') FP FP FP FP FP FP FP FP FP FP FP FP FP FP11/12/2014 21.61 BQL BQL BQL BQL BQL BQL BQL BQL BQLSee DataBQL BQL111BQL8/3/2015 21.1833.3 90.6 292 1,120BQL BQL17.8 17.6 39.7 See DataNA NA NA NA11/12/2014 22.54 BQL BQL BQL BQL BQL BQL BQL BQL BQLSee DataBQL BQL BQL BQL8/3/2015 22.24 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA11/12/2014 23.15 BQL1.94 2.15 12.3BQL BQL BQL BQL BQLSee DataBQL402 109BQL8/3/2015 22.65 BQL1.14 1.31 13.1BQL BQL BQL BQL BQL BQL NA NA NA NAMW-5 8/3/2015 21.746,610 4,970 54,800 44,900 11,600 1,580 132 67.6 621 See Data79,700 68,730 62,049BQLMW-6 8/3/2015 20.53 BQL BQL2.69 6.83BQL BQL BQL BQL BQL BQL183 260 260BQLDW-1 8/3/2015 NM BQL BQL BQL2.66BQL BQL BQL BQL BQLSee DataBQL BQL132BQLWSW-2 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NAWSW-3 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA4/13/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA4/13/2015 -- NA NA NA NA BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA4/13/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NAWSW-9 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NAWSW-10 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NANA4/13/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NAWSW-13 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NANA4/13/2015 --21.7BQL BQL31.6BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 --143BQL BQL225BQL BQL17.0 17.0 17.0NA NA NA NA NA4/13/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NAWSW-16 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NANAWSW-17 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NANA4/13/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA4/13/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NA7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NA NAWSW-23 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NANAWSW-24 7/6/2015 -- BQL BQL BQL BQL BQL BQL BQL BQL BQL NA NA NA NANA1 600 600 500 20 70 30 1 6 N/A 400 700 200 10,0005,000 84,500 260,000 85,500 20,000 70,000 12,500 1,000 5,000 N/A NS NS NS NS5 700 1,000 10,000 NS NS NS NS NS N/A NS NS NS NS= Detected Concentration Exceeds the North Carolina 2L Groundwater Quality Standards (NC2LGWQS) or the EPA Drinking Water Standard= Detected Concentration Exceeds the GCLBQL = Below Quantitation LimitsResults are reported in µg/lµg/L = micrograms per literGCL = gross contamination levelTOC = top of casingNS = No StandardN/A = Not ApplicableEPH and VPH = Extractable and Volatile Petroleum HydrocarbonsFP = Free ProductNA = Not AnalyzedNM = Not MeasuredEPA Drinking Water Standard (µg/l)C9-C18 AliphaticsC5-C8 AliphaticsGCL (µg/l)Contaminant of ConcernWSW-14WSW-15WSW-12WSW-20IPEC19-C36 AliphaticsTotal XylenesMW-2MTBE1-MethylnaphthaleneNaphthaleneTICs DetectedBenzene625BNA+10 TICs2-Methylnaphthalene602Table B-4Summary of Groundwater Analytical Results Pagetown ExxonEPH & VPHComprehensive Site AssessmentAnalytical MethodC9-C22 AromaticsNC2LGWQS Standard (µg/l)EthylbenzeneTolueneWSW-5WSW-22WSW-6WSW-7MW-4MW-3MW-1 MAP ID OWNER NAME SITE ADDRESS MAILING ADDRESS WELL USEAPPROXIMATE DISTANCE OF WELL FROM SOURCE AREA (FT.)8173 Cherry Grove RoadReidsville, NC 273208225 Cherry Grove RoadReidsville, NC 273208173 Cherry Grove RoadReidsville, NC 273208173 Cherry Grove RoadReidsville, NC 273208173 Cherry Grove RoadReidsville, NC 273208173 Cherry Grove RoadReidsville, NC 27320408 Maverick Trail DriveKing, NC 270213115 Pagetown RoadElon, NC 272443115 Pagetown RoadElon, NC 27244191 Pagetown RoadElon, NC 2724459 Pagetown RoadElon, NC 2724459 Pagetown RoadElon, NC 2724453 Pagetown RoadElon, NC 2724459 Pagetown RoadElon, NC 2724459 Pagetown RoadElon, NC 27244955 Squaw Valley TrailBurlington, NC 272177951 Cherry Grove RoadReidsville, NC 273207821 Cherry Grove RoadReidsville, NC 273207801 Cherry Grove RoadReidsville, NC 273207925 Cherry Grove RoadReidsville, NC 273207925 Cherry Grove RoadReidsville, NC 273208062 Cherry Grove RoadReidsville, NC 2732019 Deborah Daye 7801 Cherry Grove RoadPotable32222 William H. Saunders, Heirs 8062 Cherry Grove RoadPotable 15021 James Cheek 7998 Cherry Grove RoadOut-of-Use17 Hassell Terrell 7951 Cherry Grove RoadPotable1,27420 James Cheek 7925 Cherry Grove RoadPotable 39015 Garland Walker 7993 Cherry Grove RoadPotable57518 Donna Paschal 7821 Cherry Grove RoadPotable 1,11013 John Gibson 59 Pagetown RoadPotable34516 Claude Sexton, Jr. 7969 Cherry Grove RoadPotable 46011 Garland Walker 127 Pagetown RoadPotable76514 Garland Walker 7993 Cherry Grove RoadPotable 2859 Stephen Jones, Jr. 120 Pagetown RoadPotable68012 Garland Walker 59 Pagetown RoadPotable 3807 James Wrenn 78 Pagetown RoadPotable58810 Jessica Fleeger 191 Pagetown RoadPotable 9105 Inez Saunders Wrenn 8101 Cherry Grove RoadPotable3528 Stephen Jones, Jr. 120 Pagetown RoadPotable 5403 Inez Saunders Wrenn 8173 Cherry Grove RoadPotable1326 Inez Saunders Wrenn 8101 Cherry Grove RoadPotable 1501 Inez Saunders Wrenn 8035 Cherry Grove RoadOut-of-Use6404 Inez Saunders Wrenn 8173 Cherry Grove RoadPotable 580Table B-5Water-Supply Well InformationComprehensive Site AssessmentPagetown Exxon1302 Melvin Butler 8225 Cherry Grove RoadPotable 850 Map ID Name Mailing Address8062 Cherry Grove RoadReidsville, NC 273208173 Cherry Grove RoadReidsville, NC 2732059 Pagetown RoadElon, NC 272443 Garland WalkerTable B-6Adjacent Property Owner InformationComprehensive Site AssessmentPagetown Exxon1 William H. Saunders, Heirs2 Inez Saunders Wrenn MW-1 10/22/2014 2 35 20-35 Product (5.55 Feet) 99.66 FPMW-2 11/11/2014 2 30 15-30 21.18 99.85 78.67MW-3 11/11/2014 2 30 15-30 22.24 100.00 77.76MW-4 11/11/2014 2 30 15-30 22.65 99.10 76.45MW-5 7/23/2015 2 30 15-30 21.74 99.11 77.37MW-6 7/23/2015 2 30 15-30 20.53 97.53 77.00DW-1 7/22 & 23/2015 2 45 (I) 55(O) 50-55 NM 99.94 NM** - The top-of-casing elevation of each functioning well relative to a benchmark was established with an assumed elevation of 100 feet (MW-3 TOC). Relative Elevation (feet TOC)Depth (feet)Screen Interval (feet)Installation DateTable B-7Well Construction InformationComprehensive Site AssessmentPagetown ExxonGroundwater Elevation (feet)Monitoring Well IDWell Diameter (inches)Depth to Water (feet TOC) 8/3/15 O APPENDICES Comprehensive Site Assessment August 20, 2015 Pagetown Exxon Progress Project 1015059.003 Reidsville, Caswell County, North Carolina 13 P REFERENCES North Carolina Department of Natural Resources and Community Development Geologic Map of North Carolina published 1985. Underground Storage Tank Section, NCDENR Guidelines for Assessment and Corrective Action for UST Releases dated December 1, 2013. Cherry Grove, NC 7½-minute topographic maps, published by the DeLorme TopoQuads, 1997 Phase II Limited Site Assessment, prepared by Progress, dated November 26, 2014. Free Product Recovery and Water-Supply Well Sampling Report, prepared by Progress, dated May 8, 2015. Water-Supply Well Sampling Report, prepared by Progress, dated July 31, 2015. APPENDIX A WELL CONSTRUCTION RECORDS, BORING LOGS AND LITHOLOGIC DESCRIPTIONS, AND FIELD SAMPLING SHEETS APPENDIX B STANDARD SAMPLING PROCEDURES EXHIBIT A Procedures for Developing the Monitoring Wells • Well development will be performed no sooner than 24 hours after well construction is completed. • Wells will be developed by bailing or pumping a minimum of five well-volumes of groundwater from the well. • The turbidity, pH, specific conductivity, dissolved oxygen and temperature of the development water will be measured and recorded, and used as an indicator parameter to determine the completion of the development process. EXHIBIT B Procedures for Collecting Groundwater Samples • Each well will be purged of three standing well volumes prior to sample collection to remove stagnant water from the well and well bore in an effort to collect samples that are representative of the water quality in the formation surrounding each well. • Chemical preservatives, if applicable, will be added to sample bottles by the laboratory. • Sample bottles will be labeled prior to sample collection. • Sample bottles will be filled directly from the Teflon or disposable bailer. Volatile organic samples will be collected first. • The pH, temperature, and specific conductance of the sample will be measured and recorded. These measurements will be taken from a sample deposited in a separate container. Visual characteristics of the sample, including insoluble materials, will be recorded. • Caps will be secured on bottles, bottle will be placed in plastic bags and the bags will be sealed. • Documentation, including Chain-of-Custody Record and laboratory analytical request form, will be completed for all samples. • Samples will be packed in coolers with "bubble wrap" and ice packs for shipment. • Chain-of-Custody Record and analytical request form will be placed inside cooler sealed with security tape. • Samples will be shipped via overnight express to the analytical laboratory within 24 hours following collection. • Laboratory will be advised of each sample shipment. APPENDIX C LABORATORY REPORT FOR GROUNDWATER SAMPLES AND CHAIN-OF-CUSTODY RECORDS APPENDIX D RECOVERY TEST DATA AND CALCULATIONS HYDRAULIC CONDUCTIVITY TEST DATA AND CALCULATIONS - HVORSLEV METHOD PAGETOWN EXXON, REIDSVILLE, NORTH CAROLINA PROGRESS PROJECT NO. 1015059.003 MONITORING WELL MW-2 8/3/2015 Total Depth 30 ft Screened Length 15 ft Static Water Level 21.18 ft Well Radius (r) 1 in = 2.54 cm Anulus Radius (R) 3.125 in = 7.9375 cm If rise/fall is in sand pack replace r with re = {r2 + 0.3(R2 - r2)}1/2 :re=4.84 cm Interpolation DH / Hi 0.419 Time 7.00 closest T above H/Hi = .37 DH / Hi 0.378 T(0) = 8.00 (interpolates T at H / Hi is .37) DH / Hi 0.331 Time 9.00 closest T below H/Hi = .37 DH / Hi 0.37 T(0) = 7.7 from graph Hydraulic Conductivity = r2 [ln(Leff/R)]/2*Leff*T(0) L(eff) = 8.82 ft (depth - static water level L(eff) = 268.8 cm or screen length) Results -based on T(0) from interpolation T(0) = 480.0 sec Hydraulic Conductivity = 3.20E-04 cm/sec Hydraulic Conductivity = 0.91 ft/day Hydraulic Conductivity = 330.7 ft/yr Results - based on T (0) from Graph T(0) = 462.0 sec Hydraulic Conductivity = 3.32E-04 cm/sec Hydraulic Conductivity = 0.94 ft/day Hydraulic Conductivity = 343.6 ft/yr Elapsed Elapsed Elapsed Time D H DH / Hi Time D H DH / Hi Time D H DH / Hi 0 1.48 1.000 20 0.16 0.108 0.25 1.44 0.973 25 0.11 0.074 0.5 1.4 0.946 0.75 1.32 0.892 1 1.27 0.858 1.25 1.22 0.824 1.5 1.18 0.797 1.75 1.13 0.764 2 1.10 0.743 2.5 1.03 0.696 3 0.97 0.655 3.5 0.92 0.622 4 0.85 0.574 4.5 0.80 0.541 5 0.77 0.520 6 0.70 0.473 7 0.62 0.419 8 0.56 0.378 9 0.49 0.331 10 0.44 0.297 15 0.28 0.189 0.1001.0000 2 4 6 8 10 12 14 16H/HiTime in MinutesSlug Test Results - Pagetown ExxonMW-2, 8/3/20150.377.7 Min. HYDRAULIC CONDUCTIVITY TEST DATA AND CALCULATIONS - HVORSLEV METHOD PAGETOWN EXXON, REIDSVILLE, NORTH CAROLINA PROGRESS PROJECT NO. 1015059.003 MONITORING WELL MW-4 8/3/2015 Total Depth 30 ft Screened Length 15 ft Static Water Level 22.65 ft Well Radius (r) 1 in = 2.54 cm Anulus Radius (R) 3.125 in = 7.9375 cm If rise/fall is in sand pack replace r with re = {r2 + 0.3(R2 - r2)}1/2 :re=4.84 cm Interpolation DH / Hi 0.428 Time 15.00 closest T above H/Hi = .37 DH / Hi 0.37 T(0) = 20.00 (interpolates T at H / Hi is .37) DH / Hi 0.256 Time 25.00 closest T below H/Hi = .37 DH / Hi 0.37 T(0) = 14.4 from graph Hydraulic Conductivity = r2 [ln(Leff/R)]/2*Leff*T(0) L(eff) = 7.35 ft (depth - static water level L(eff) = 224.0 cm or screen length) Results -based on T(0) from interpolation T(0) = 1200.0 sec Hydraulic Conductivity = 1.45E-04 cm/sec Hydraulic Conductivity = 0.41 ft/day Hydraulic Conductivity = 150.5 ft/yr Results - based on T (0) from Graph T(0) = 864.0 sec Hydraulic Conductivity = 2.02E-04 cm/sec Hydraulic Conductivity = 0.57 ft/day Hydraulic Conductivity = 209.1 ft/yr Elapsed Elapsed Elapsed Time D H DH / Hi Time D H DH / Hi Time D H DH / Hi 0 2.15 1.000 20 0.72 0.335 0.25 2.11 0.981 25 0.55 0.256 0.5 2.05 0.953 30 0.46 0.214 0.75 2.01 0.935 1 1.98 0.921 1.25 1.95 0.907 1.5 1.91 0.888 1.75 1.86 0.865 2 1.83 0.851 2.5 1.76 0.819 3 1.71 0.795 3.5 1.65 0.767 4 1.6 0.744 4.5 1.56 0.726 5 1.51 0.702 6 1.44 0.670 7 1.35 0.628 8 1.3 0.605 9 1.21 0.563 10 1.16 0.540 15 0.92 0.428 0.1001.0000 2 4 6 8 10 12 14 16H/HiTime in MinutesSlug Test Results - Pagetown ExxonMW-4, 8/3/20150.3714.4 Min.