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Home My WebLink AboutRA-2760_17579_CA_MRP_20170713Groundwater Monitoring Report July 13, 2017 Petro Mark Exxon, Henderson, North Carolina Progress Project No. 1017122.001 i TABLE OF CONTENTS A SITE IDENTIFICATION ............................................................................................................ 1 B CAP IMPLEMENTATION ........................................................................................................ 2 C FIELD ACTIVITIES .................................................................................................................... 2 D LABORATORY TEST RESULTS ............................................................................................. 2 E REGIONAL GEOLOGY AND HYDROGEOLOGY ............................................................. 3 F SITE GEOLOGY AND HYDROGEOLOGY .......................................................................... 4 G DETERMINATION OF GROUNDWATER FLOW DIRECTION ..................................... 4 H CONCLUSIONS ........................................................................................................................... 4 I RECOMMENDATIONS ............................................................................................................. 5 FIGURES Figure 1. Topographic Site Map Figure 2. Site Plan Figure 3. Groundwater Analytical Results Map Figure 4. Benzene Isopleth Map Figure 5. BTEX Isopleth Map Figure 6. MTBE Isopleth Map Figure 7. Potentiometric Surface Map TABLES Table B-4 -- Summary of Groundwater Analytical Results Table B-7 -- Well Construction Information APPENDIX Groundwater Sampling Sheets Laboratory Data Sheets and Chain-of-Custody Records Groundwater Monitoring Report July 13, 2017 Petro Mark Exxon, Henderson, North Carolina Progress Project No. 1017122.001 2 B CAP IMPLEMENTATION The site is the Petro Mark Exxon located at 822 Satterwhite Point Road in Henderson, Vance County, North Carolina (Figure 1 and Figure 2). As requested by the North Carolina Department of Environmental Quality (NCDEQ), Progress Environmental, Inc. (Progress) was contracted by McLeod Oil Company to complete a groundwater sampling event at the site to determine the current groundwater quality beneath the site. Previous assessment and remediation activities at the site have included the installation and sampling of monitoring wells and the recovery of free product from monitoring well MW-3. C FIELD ACTIVITIES GROUNDWATER INVESTIGATION Progress collected groundwater samples from: monitoring wells MW-1, MW-2, MW-3, MW-5, MW-6, MW-7, MW-8, MW-9, MW-10, MW-11, MW-14, MW-15, MW-16, MW-17, MW-18, MW-19, MW-20, MW-21, MW-22, and DW-1, and the water-supply well located on an adjacent property to the northwest on June 13, 2017. The groundwater samples were sent to a North Carolina-certified laboratory to be analyzed for volatile organic compounds (VOCs) by Standard Method 6200B. A summary of the analytical results (including historical groundwater analytical results detected during the previous sampling events) is presented in Table B-4. The groundwater analytical results were evaluated using the North Carolina Administrative Code (NCAC) Title 15A NCDEQ, Subchapter 2L, Section .0200, Classifications and Water Quality Standards (NC2LGWQS). In addition, the Gross Contamination Levels (GCLs) as presented in the 2013 NCDEQ Guidelines were also used for evaluation purposes. Laboratory analysis of the groundwater samples collected from monitoring wells MW-1, MW-2, MW-3, MW-5, MW-6, MW-16, MW-17, and MW-20 detected concentrations of petroleum-related compounds exceeding their respective NC2LGWQS. Please note, the detected concentrations of targeted petroleum-related exceed the applicable GCLs in the groundwater sample collected from monitoring well MW-2. Laboratory analysis of the samples collected from the nearby water- supply well did not detect targeted compounds above the laboratory quantitation limits. D LABORATORY TEST RESULTS The results of the June 13, 2017 groundwater sampling event indicate the following: • Laboratory analysis of the groundwater samples collected from monitoring wells MW-7, MW-8, MW-9, MW-10, MW-11, MW-14, MW-15, MW-18, MW-19, MW-21, MW-22, and DW-1, and the water-supply well did not detect targeted compounds above the NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring well MW-1 detected benzene (920 µg/L), ethylbenzene (3,610 µg/L), iso-propylbenzene (280 µg/L), naphthalene (1,480 µg/L), n-propylbenzene (680 µg/L), toluene (10,800 µg/L), 1,2,4- trimethylbenzene (3,960 µg/L), 1,3,5-trimehtylbenzene (1,190 µg/L), and total xylenes (17,400 µg/L) above their respective NC2LGWQS. Groundwater Monitoring Report July 13, 2017 Petro Mark Exxon, Henderson, North Carolina Progress Project No. 1017122.001 3 • Laboratory analysis of the groundwater samples collected from monitoring well MW-2 detected benzene (1,750 µg/L), ethylbenzene (5,550 µg/L), iso-propylbenzene (1,850 µg/L), naphthalene (16,700 µg/L), n-butylbenzene (12,750 µg/L), n-propylbenzene (11,600 µg/L), p-isopropyltoluene (2,550 µg/L), sec-butylbenzene (4,830 µg/L), toluene (21,900 µg/L), 1,2,4-trimethylbenzene (101,000 µg/L), 1,3,5-trimehtylbenzene (32,300 µg/L), and total xylenes (34,000 µg/L) above their respective NC2LGWQS. Please note, the concentrations of naphthalene, n-butylbenzene, 1,2,4-trimethylbenzene. and 1,3,5- trimethylbenzene exceed the applicable Gross Contamination Levels (GCLs). • Laboratory analysis of the groundwater samples collected from monitoring well MW-3 detected benzene (1,310 µg/L), ethylbenzene (3,050 µg/L), iso-propylbenzene (300 µg/L), MTBE (400 µg/L), naphthalene (795 µg/L), n-butylbenzene (315 µg/L), n-propylbenzene (1,120 µg/L), toluene (22,800 µg/L), 1,2,4-trimethylbenzene (7,140 µg/L), 1,3,5- trimehtylbenzene (2,150 µg/L), and total xylenes (14,800 µg/L) above their respective NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring well MW-5 detected benzene (425 µg/L), ethylbenzene (1,370 µg/L), iso-propylbenzene (87.0 µg/L), naphthalene (268 µg/L), n-propylbenzene (212 µg/L), toluene (3,890 µg/L), 1,2,4- trimethylbenzene (1,460 µg/L), 1,3,5-trimehtylbenzene (407 µg/L), and total xylenes (5,660 µg/L) above their respective NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring well MW-6 detected MTBE (54.0 µg/L), naphthalene (140 µg/L), 1,2,4-trimethylbenzene (1,350 µg/L), 1,3,5-trimehtylbenzene (705 µg/L), and total xylenes (2,640 µg/L) above their respective NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring well MW-16 detected benzene (54.3 µg/L), naphthalene (40.2 µg/L), and total xylenes (526 µg/L) above their respective NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring well MW-17 detected MTBE (36.9 µg/L) above its NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring well MW-20 detected naphthalene (8.07 µg/L) above its NC2LGWQS. Based on the calculated groundwater flow direction, groundwater beneath the site is generally migrating to the east-southeast. Groundwater elevation data is provided in Table B-7 and Figure 7. E REGIONAL GEOLOGY AND HYDROGEOLOGY According to the Geologic Map of North Carolina, the subject site is located in the Raleigh Belt of the Piedmont Physiographic Province of North Carolina. The site is located in an area underlain by rocks composed of foliated and massive granitic rock. In the Piedmont Physiographic Province, groundwater generally occurs under water-table conditions and is stored in the pore space between individual grains of residual soil and in the fractures within the underlying parent rock. Due to the Groundwater Monitoring Report July 13, 2017 Petro Mark Exxon, Henderson, North Carolina Progress Project No. 1017122.001 4 intense shearing associated with the thrust faulting in the area, 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. F SITE GEOLOGY AND HYDROGEOLOGY Based on our review of the topographic map and on-site observation, the site is located on top of a northeast-sout 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 likely flows to the east-southeast towards Anderson Creek (Figure 1). G DETERMINATION OF GROUNDWATER FLOW DIRECTION The depth to the groundwater surface in each of the monitoring wells was measured prior to the monitoring well purging using a decontaminated electric sounder. The tops of casing of the wells were previously surveyed by others. The elevations of the monitoring wells and the groundwater surface are both relative to a benchmark. The relative groundwater elevations are shown in Table B-7. H CONCLUSIONS Based on laboratory analysis of the most recent sampling event Progress makes the following conclusions: • Progress located and sampled 20 groundwater monitoring wells and one nearby water- supply well. • Laboratory analysis of the groundwater samples collected from monitoring wells MW-7, MW-8, MW-9, MW-10, MW-11, MW-14, MW-15, MW-18, MW-19, MW-21, MW-22, and DW-1, and the water-supply well did not detect targeted compounds above the NC2LGWQS. • Laboratory analysis of the groundwater samples collected from monitoring wells MW-1, MW-2, MW-3, MW-5, MW-16, MW-17, and MW-20 detected targeted compounds at concentrations exceeding their respective NC2LGWQS. Additionally, targeted petroleum- related compounds were detected in the groundwater sample collected from monitoring well MW-2 at concentrations that exceed the applicable GCLs. • As compared to historical data, the results of the most recent sampling event depict results that are similar to the results reported from the sampling events in 2002 and 2003. Groundwater Monitoring Report July 13, 2017 Petro Mark Exxon, Henderson, North Carolina Progress Project No. 1017122.001 5 I RECOMMENDATIONS Based on the results of the most recent sampling event, Progress makes the following the recommendations: • Commence discussions with the NCDEQ personnel regarding the implementation of active remediation at the site. J FIGURES Figure 1 Topographic Site Map Petro Mark Exxon 822 Satterwhite Point Road Henderson, Vance County, North Carolina P.O. Box 5884 Winston-Salem, NC 27113 Telephone: (336) 722-9999 Fax: (336) 722-9998 www.progressenvironmental.com Henderson N.C. United States Department of the Interior United States Geological Survey 7.5 Minute Series Topographic Map Contour Interval: 10 feet Scale: 1:24,000 Date: 2016 Project: Petro Mark Exxon Client: McLeod Oil Company Progress Job #: 1017122.001 Date: July 2017 SITE Site K TABLES Well IDDate Collected (m/dd/yy)Depth to Water (Ft. Below TOC)MW-1 6/13/2017 26.55920BQL BQL3,610BQL280BQL1,480BQL680BQL BQL10,800 3,960 1,190 17,400MW-2 6/13/2017 24.981,750BQL BQL5,550BQL1,850BQL16,700 12,750 11,600 2,550 4,830 21,900 101,000 32,300 34,000MW-3 6/13/2017 24.851,310BQL BQL3,050BQL300 400 795 315 1,120BQL BQL22,800 7,140 2,150 14,800MW-5 6/13/2017 18.65425BQL BQL1,370BQL87.0BQL268BQL212BQL BQL3,890 1,460 407 5,660MW-6 6/13/2017 20.97 BQL BQL BQL158BQL BQL54.0 140 50.0BQL BQL BQL93.0 1,350 705 2,640MW-7 6/13/2017 23.22 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLBQL BQL BQL BQL BQLMW-8 6/13/2017 23.29 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLBQL BQL BQL BQL BQLMW-9 6/13/2017 24.07 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLBQL BQL BQL BQL BQLMW-10 6/13/2017 23.02 BQL1.25BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-11 6/13/2017 23.90 BQL BQL BQL BQL BQL BQL2.80BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-14 6/13/2017 17.07 BQL BQL BQL BQL0.58BQL10.1BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-15 6/13/2017 20.70 BQL BQL BQL BQL BQL BQL2.91BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-16 6/13/2017 17.1354.3BQL BQL272 2.90 15.0 12.5 40.2 2.20 21.5 0.76 1.61 48.5 7.92 13.7 526MW-17 6/13/2017 17.87 BQL BQL BQL BQL4.56BQL36.9BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-18 6/13/2017 17.84 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-19 6/13/2017 18.33 BQL0.84BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-20 6/13/2017 11.25 BQL BQL BQL BQL BQL BQL BQL8.07BQL BQL BQL BQL BQL BQL BQL BQLMW-21 6/13/2017 15.72 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLMW-22 6/13/2017 16.24 BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQLDW-1 6/13/2017 24.98 BQL BQL BQL BQL BQL BQL BQL1.48BQL BQL BQL BQL BQL BQL BQL BQLWSW-1 6/13/2017 NM BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL BQL1 70 0.4 600 70 70 20 6 70 70 70 25 600 400 400 5005,000 70,000 400 84,500 70,000 25,000 20,000 6,000 6,900 30,000 70,000 11,700 260,000 28,500 25,000 85,500= Detected Concentration Above the North Carolina 2L Groundwater Quality Standard (NC2LGWQS)= Detected Concentration Above the Gross Contamination Level BQL = Below Quantitation LimitsResults are reported in µg/Lµg/L = micrograms per literGCL = gross contamination levelTOC = top of casingNS = No StandardN/A = Not ApplicableNA = Not AnalyzedEPH and VPH = Extractable and Volatile Petroleum HydrocarbonsGCL (µg/L)Contaminant of ConcernNC2LGWQS (µg/L)Ethylbenzene n-PropylbenzeneIPEBenzeneChloroform1,2-DichloroethaneI-PropylbenzeneMTBENaphthaleneN-Butylbenzenesec-ButylbenzeneTable B-4Summary of Groundwater Analytical Results Groundwater Monitoring ReportPetro Mark ExxonNCDEQ Incident No. 17579Analytical MethodTolueneP-Isopropyltoulene6200B1,2,4-Trimethylbenzene1,3,5-TrimethylbenzeneTotal Xylenes 6/13/2017 6/13/2017MW-1 6/26/1999 2 35.5 25.5-35.5 26.55 492.63 466.08MW-2 4/11/1997 2 30 20-30 24.98 492.54 467.56MW-3 6/26/1999 2 38.5 18.5-38.5 24.85 492.39 467.54MW-4 4/9/1997 2 22 12-22 NM 484.71 NMMW-5 4/9/1997 2 22 12-22 18.65 482.39 463.74MW-6 4/9/1997 2 22 12-22 20.97 487.58 466.61MW-7 4/10/1997 2 30 20-30 23.22 491.23 468.01MW-8 8/27/1997 2 25 10-25 23.29 489.66 466.37MW-9 8/27/1997 2 30 20-30 24.07 491.83 467.76MW-10 8/27/1999 2 30 20-30 23.02 491.18 468.16MW-11 8/27/1999 2 28 18-2823.9492.45 468.55MW-12 2/16/1999 2 22.5 12.5-22.5NM480.99 NMMW-13 2/17/1999 2 28 18-28NM486.03 NMMW-14 2/17/1999 2 23 13-2317.07479.47 462.40MW-15 2/17/1999 2 36.7 16.7-36.720.70489.61 468.91MW-16 6/9/1999 2 23 15-2517.13479.86 462.73MW-17 6/9/1999 223 13-23 17.87 472.4454.53MW-18 6/9/1999 224 14-24 17.84 480.49462.65MW-19 12/6/1999 235 15-35 18.33 477.91459.58MW-20 11/9/1999 220 10-20 11.25 464.9453.65MW-21 11/9/1999 228 18-28 15.72 470.61454.89MW-22 11/9/1999 228 18-28 16.24 469.46453.22MW-24 11/10/1999 219 10-19 NM 460.29NMDW-1 2/18/19992 107 102-107 26.95 493.13 466.18** - The top-of-casing elevation of each functioning well relative to a benchmark was established with an assumed elevation of 100 feet (MW-1 TOC). NM = Not MeasuredNCDEQ Incident No. 17579 Depth to Water (feet TOC) Table B-7Well Construction Information and Historical Groundwater ElevationsPetro Mart ExxonGroundwater Monitoring ReportWell Diameter (inches)Relative Elevation (feet TOC)Depth (feet)Screen Interval (feet)Installation DateMonitoring Well IDGroundwater Elevation (feet) L APPENDIX LABORATORY DATA SHEETS AND CHAIN-OF-CUSTODY RECORD