WS-7722_37055_CA_LTTRRPT_20230317

2725 E. Millbrook Road, Suite 121
Raleigh, NC 27604
Telephone [phone]
www.atcgroupservices.com

ATC Project No. SLC3705505 NCDEQ State Lead Program

March 17, 2023

Ms. Linda Blalock
North Carolina Department of Environmental Quality
Division of Waste Management – Underground Storage Tank Section
1646 Mail Service Center
Raleigh, NC 27699

Subject: Free Product Recovery and Groundwater Monitoring Letter Report
IDC, Inc.
2841 Highway 311
Madison, Rockingham County, North Carolina
NCDEQ Indicent No. 37055
UST No. WS-7722

Dear Ms. Blalock:

ATC Associates of North Carolina, P.C. (ATC) is pleased to submit the results of a Mobile Multi-Phase
Extraction (MMPE) event and groundwater monitoring event at the IDC, Inc. site located at 2841 Highway
311 in Madison, Rockingham County, North Carolina. The IDC, Inc. site was a former service station and
radiator shop and is currently vacant with one dilapidated single-story building. Four monitoring wells
(MW-1 through MW-4) are associated with the site. Nineteen potable water supply wells are located
within 1,000 feet of the site. Municipal water is available to the area. Figure 1 depicts the site on a
topographic map and Figure 2 is a site map with pertinent site features. A potential receptor map is
included as Figure 3.

The MMPE and subsequent sampling event were performed based on the December 16, 2022, Task
Authorization (TA-5) by the Trust Fund Branch of the Underground Storage Tank (UST) Section, Division
of Waste Management, North Carolina Department of Environmental Quality (NCDEQ). The work is being
performed as part of the State Lead Contract #N122019A between NCDEQ and ATC.

As part of the prior TA-4, ATC performed groundwater monitoring activities at the site on November 22,
2022. During the event, light non-aqueous phase liquid (LNAPL) was detected in well MW-1 at a
thickness of 0.09 feet. Depth to groundwater was recorded at 30.08 feet below ground surface (bgs).
Based on the results of the sampling event, NCDEQ requested the completion of a MMPE event.

Eastern Environmental Management, LLC (Eastern) was subcontracted to perform the MMPE event from
January 23 through January 27, 2023. Monitoring well MW-1 was used as the extraction point for the
event. Monitoring well construction details are included as Table 1.

On January 23, 2023, monitoring wells MW-1, MW-2, and MW-3 were gauged using an oil/water interface
probe. LNAPL was not detected in any of the three monitoring wells. Depth to groundwater was measured at
28.53 feet bgs in MW-1, 26.27 feet bgs in MW-2, and 25.88 feet bgs in MW-3. Throughout the MMPE event,
the intake was adjusted to maximize volume recovery. The MMPE event was initiated at 10:00 a.m.

The MMPE event was concluded at 10:00 a.m. on January 27, 2023. Following the event, depth to
groundwater was measured at 29.03 feet bgs in MW-1, 26.27 feet bgs in MW-2, and 25.68 feet bgs in MW-3.
Depth to groundwater measurements are shown on Table 1. The MMPE report is included as Appendix A.
Approximately 4,763 gallons of impacted groundwater and 32.39 gallons of petroleum vapor were recovered
during the event. The waste disposal manifest is included as Appendix B. Field notes are included in
Appendix C. Site photographs are included in Appendix D.

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

ATC mobilized to collect a groundwater sample from MW-1 on February 24, 2023. No LNAPL was detected
during the event. Depth to groundwater was recorded at 27.20 feet below ground surface. Benzene
concentrations in MW-1 exceeded the Gross Contamination Levels (GCLs). Concentrations of toluene,
ethylbenzene, total xylenes, naphthalene, di-isopropyl either, isopropylbenzene, n-propylbenzene, styrene,
1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzne in MW-1 exceeded their respective 15A NCAC 02L .0202
Groundwater Standards. Current analytical results are reported in Table 3. Historical analytical results are
included in Table 4 and natural attenuation data is reported in Table 5.

Based on the MW-1 analytical data from September 2021, the MMPE event appears to have been
ineffective in reducing concentrations of benzene below GCLs. However, based on the amount of
groundwater and vapor recovery, ATC recommends performing another MMPE event to recover
additional impacted groundwater in an attempt to reduce benzene below GCLs.

If you have any questions or require additional information, please contact our office at [phone].

Sincerely,

ATC Associates of North Carolina, P.C.

Corinne Lally Ashley M. W. Offer, P.G.
Staff Scientist Senior Project Manager
Direct Line: 919-948-7379 Direct Line: 919-573-1206
Email: [e-mail] Email: [e-mail]

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

Attachments:

Table 1 – Water Supply Well Information
Table 2 – Well Construction and Groundwater Elevation Data
Table 3 – Analytical Data
Table 4 – Historical Analytical Data
Table 5 – Natural Attenuation Parameters
Figure 1 – Topographic Map
Figure 2 – Site Map
Figure 3 – Potential Receptor Map
Appendix A – MMPE Report
Appendix B – Waste Disposal Manifest
Appendix C – Field Notes
Appendix D – Site Photographs

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

TABLES

TABLE 1
WATER SUPPLY WELL INFORMATION
IDC, INC.
2841 HIGHWAY 311
MADISON, ROCKINGHAM COUNTY, NORTH CAROLINA
INCIDENT #37055
Well ID Property Owner Property Owner Address Property Address
Estimated Distance
and Direction from
Source
Connected to a
Municipal Water
Supply
Usage
WSW-1 Fred &
Melinda Rasch
6003 Lomond Drive
Summerfield,
NC 27358
2883 US Hwy 311
Madison,
NC 27025
390 W Yes Abandoned
WSW-2 Carlos &
Sctaria Malloy
2881 US Hwy 311
Madison,
NC 27025
2881 US Hwy 311
Madison,
NC 27025
360 W Yes Abandoned
WSW-3 Kelly Fulp
2873 US Hwy 311
Madison,
NC 27025
2873 US Hwy 311
Madison,
NC 27025
340 WNW No Drinking Water
WSW-4 Eddie
Sizemore
1619 Rhodes Loop
Madison,
NC 27025
2863 US Hwy 311
Madison,
NC 27025
190 W No Drinking Water
WSW-5 Betty
McCandless
2853 US Hwy 311
Madison,
NC 27025
2853 US Hwy 311
Madison,
NC 27025
60 W Yes Abandoned
WSW-6 Clementina
Garcia-Rios
723 Beaver Creek Road
Madison, NC
27027
2831 US Hwy 311
Madison,
NC 27025
90 ENE No Drinking Water
WSW-7 Hendley &
Gladys Pruitt
2807 US Hwy 311
Madison,
NC 27025
2807 US Hwy 311
Madison,
NC 27025
280 ENE No Drinking Water
WSW-8 Joyce Law &
Allison Brenda
2783 US Hwy 311
Madison,
NC 27025
2783 US Hwy 311
Madison,
NC 27025
460 ENE No Drinking Water
WSW-9 Richard &
Pamela Hill
2798 US Hwy 311
Madison,
NC 27025
2798 US Hwy 311
Madison,
NC 27025
490 E No Drinking Water
WSW-10 Roy & Martha
Reid
2804 US Hwy 311
Madison,
NC 27025
2804 US Hwy 311
Madison,
NC 27025
383 ESE No Drinking Water
WSW-11 Kenneth
McCandless
PO Box 410
Madison, NC
27025
2820/2844 US Hwy 311
Madison, NC
27025
310 SE No Drinking Water
WSW-12 Kenneth
McCandless
PO Box 410
Madison, NC
27025
2858/2862 US Hwy 311
Madison, NC
27025
260 SW No Drinking Water
WSW-13 Bobby Mabe
140 Dodge Loop
Madison,
NC 27025
140 Dodge Loop
Madison,
NC 27025
370 S No Drinking Water
WSW-14 Zara Mabe
176 Dodge Loop
Madison,
NC 27025
176 Dodge Loop
Madison,
NC 27025
500 SE No Drinking Water
WSW-15 Zara Mabe
176 Dodge Loop
Madison,
NC 27025
232 Dodge Loop
Madison,
NC 27025
905 SE No Drinking Water
WSW-16 George &
Betty Gatewood
2750 US Hwy 311
Madison,
NC 27025
231 Dodge Loop
Madison,
NC 27025
965 SE No Drinking Water
WSW-17 George &
Betty Gatewood
2750 US Hwy 311
Madison,
NC 27025
2750 US Hwy 311
Madison,
NC 27025
1,000 E No Drinking Water
WSW-18 James &
Janelle Wagoner
2780 US Hwy 311
Madison,
NC 27025
2790 US Hwy 311
Madison,
NC 27025
570 E Yes Abandoned
WSW-19 Deborah &
Bernard Morris
6103 Graham Hobgood Road
Oxford,
NC 27565
2885 US Hwy 311
Madison,
NC 27025
650 W No Drinking Water
WSW-20 Edgar &
Sandra Cooper
2915 US Hwy 311
Madison,
NC 27025
2915 US Hwy 311
Madison,
NC 27025
820 SW No Drinking Water
WSW-21 Irene Nixon
2932 US Hwy 311
Madison,
NC 27025
2932 US Hwy 311
Madison,
NC 27025
900 SW No Drinking Water
WSW-22 Bobby O'Neal
2930 US Hwy 311
Madison,
NC 27025
2930 US Hwy 311
Madison
NC 27025
850 SW No Drinking Water
WSW-23 James &
Carolyn Hazelwood
2940 US Hwy 311
Madison,
NC 27025
2910 US Hwy 311
Madison,
NC 27025
650 SW No Drinking Water
Note: Only water supply wells located within 1,000 feet of the site are included on this table.
Page 1 of 1
TABLE 2
WELL CONSTRUCTION AND GROUNDWATER ELEVATION DATA
IDC, INC.
2841 HIGHWAY 311
MADISON, ROCKINGHAM COUNTY, NORTH CAROLINA
INCIDENT #37055
Well ID Date
Installed
Screened
Interval
(ft.)
Depth of
Well (ft.)
TOC
Elev. (ft.)Date Measured Depth to
LNAPL
Depth to
Water
LNAPL
Thickness
Groundwater
Elevation
3/20/2018 --26.12 --71.18
10/25/2019 --26.72 --70.58
2/19/2021 19.02 20.52 1.50 78.07
6/14/2021 (Pre-MMPE)20.55 21.10 0.55 76.67
6/18/2021 (Post-MMPE)--28.64 --68.66
9/22/2021 --23.97 --73.33
11/22/2022 29.99 30.08 0.09 67.30
1/23/2023 (Pre-MMPE)--28.53 --68.77
1/27/2023 (Post-MMPE)--29.03 --68.27
2/24/2023 --27.20 --70.10
6/21/2018 --25.91 --72.41
10/25/2019 --18.60 --79.72
2/19/2021 --15.95 --82.37
6/14/2021 (Pre-MMPE)--16.56 81.76
6/18/2021 (Post-MMPE)--16.84 --81.48
1/23/2023 (Pre-MMPE)--26.27 --72.05
1/27/2023 (Post-MMPE)--26.27 --72.05
6/21/2018 --26.57 --70.05
10/25/2019 --26.45 --70.17
2/19/2021 --18.27 --78.35
6/14/2021 (Pre-MMPE)--19.33 --77.29
6/18/2021 (Post-MMPE)--19.95 --76.67
1/23/2023 (Pre-MMPE)--25.88 --70.74
1/27/2023 (Post-MMPE)--25.68 --70.94
6/21/2018 --25.12 --69.72
10/25/2019 --25.10 --69.74
2/19/2021 --16.61 --78.23
6/14/2021 (Pre-MMPE)--18.11 --76.73
6/18/2021 (Post-MMPE)--18.56 --76.28
Notes:
3. TOC = Top of casing.
4. Groundwater elevation calculated using the following formula: TOC Elevation - Depth to GW + (0.8581*LNAPL Thickness).
1. LNAPL = Light Non-Aqueous Phase Liquid.
2. -- = LNAPL not detected.
6/20/18MW-2 25-35 35.00 98.32
MW-4 6/20/18 25-35 35.00 94.84
MW-3 6/20/18 25-35 35.00 96.62
MW-1 3/19/2018 20-35 35.00 97.30
TABLE 3
GROUNDWATER ANALYTICAL RESULTS
IDC, INC.
2841 HIGHWAY 311
MADISON, ROCKINGHAM COUNTY, NORTH CAROLINA
INCIDENT #37055
Client Sample
ID:Date Sampled:BenzeneTolueneEthylbenzeneTotal XylenesMethyl Tert Butyl EtherNaphthaleneDi-Isopropyl Ethern-ButylbenzeneIsopropylbenzenen-PropylbenzeneStyrene1,2,4-Trimethylbenzene1,3,5-TrimethylbenzeneMW-1 2/24/2023 13,100 24,900 2,320 15,400 <250 988 77.8 J 46.6 J 84.1 J 267 90.1 J 2,810 659
1 600 600 500 20 6 70 70 70 70 70 400 400
5,000 260,000 80,000 50,000 20,000 6,000 70,000 5,900 30,500 26,100 70,000 28,500 24,100
Notes:
1. "<" or ND = Not detected at or above the laboratory detection limit.
2. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb).
3. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality Standard (2L Standard).
4. Concentrations in bold and italics exceed the corresponding NCDEQ Groundwater Quality 2L Standards and GCL.
5. GCL = Gross Contamination Limit.
6. J = Indicates an estimated value.
6200B
2L Standard
GCL
Analytical Method
TABLE 4
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
IDC, INC.
2841 HIGHWAY 311
MADISON, ROCKINGHAM COUNTY, NORTH CAROLINA
INCIDENT #37055
Well ID Date
Collected
Benzene Toluene Ethylbenzene Total Xylenes Methyl Tert Butyl EtherNaphthalene AcetoneBromodichloromethanen-Butylbenzene Chloroform DibromochloromethaneDi-Isopropyl EtherIsopropylbenzene2-Hexanone (MBK)Methylene Chloriden-Propylbenzene Styrene1,2,4-Trimethylbenzene 1,3,5-Trimethylbenzene 3/20/2018 23,000 42,000 3,600 19,000 1,100 450 620 <25 35 <25 <25 230 100 130 <100 300 82 1,800 490
10/25/2019 17,400 34,100 3,060 16,170 773 1,180 NA <125 <125 <125 <125 178 <125 NA <500 <125 <125 2,750 <125
2/19/2021
9/22/2021 13,400 24,200 2,110 12,300 328 1,130 <5,000 <250 <250 <250 <100 146 J 80.6 J <500 301 307 <250 2,920 686
2/24/2023 13,100 24,900 2,320 15,400 <250 988 <5,000 <250 46.6 J <250 <100 77.8 J 84.1 J <500 <250 267 90.1 J 2,810 659
6/21/2018 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <2.0 <0.5 <0.5 <0.5 <0.5
10/25/2019 <0.5 <0.5 <0.5 <1.5 <0.5 <2.0 NA 2.2 <0.5 1.7 <0.5 <0.5 <0.5 NA <2.0 <0.5 <0.5 <0.5 <0.5
2/19/2021 <0.50 <0.50 <0.50 <0.50 a <0.50 a <0.50 <10 a 23.0 b <0.50 74.2 b 5.1 <0.50 <0.50 <1.0 <0.50 <0.50 <0.50 <0.50 <0.50
6/21/2018 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <2.0 <0.5 <0.5 <0.5 <0.5
10/25/2019 <0.5 <0.5 <0.5 <1.5 <0.5 <2.0 NA <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <2.0 <0.5 <0.5 <0.5 <0.5
2/19/2021 <0.50 <0.50 <0.50 <0.50 a <0.50 a <0.50 <10 a <0.50 a <0.50 <0.50 a <0.20 <0.50 <0.50 <1.0 <0.50 <0.50 <0.50 <0.50 <0.50
6/21/2018 1.3 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <2.0 <0.5 <0.5 <0.5 <0.5
10/25/2019 <0.5 <0.5 <0.5 <1.5 <0.5 <2.0 NA <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <2.0 <0.5 <0.5 <0.5 <0.5
2/19/2021 <0.50 <0.50 <0.50 <0.50 a <0.50 a <0.50 <10 a <0.50 a <0.50 <0.50 a <0.20 <0.50 <0.50 <1.0 <0.50 <0.50 <0.50 <0.50 <0.50
1 600 600 500 20 6 6,000 0.6 70 70 0.4 70 70 40 400 70 70 400 400
5,000 260,000 80,000 50,000 20,000 6,000 6,000,000 NE 5,900 70,000 400 70,000 30,500 40,000 400,000 26,100 70,000 28,500 24,100
Notes:
1. "<" or ND = Not detected at or above the laboratory detection limit.
2. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb).
3. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality Standard (2L Standard).
4. Concentrations in bold and italics exceed the corresponding NCDEQ Groundwater Quality 2L Standards and GCL.
5. GCL = Gross Contamination Limit.
6. NE = Not established.
7. a = Associated CCV outside of control limits high, sample was ND.
8. b = Associated CCV outside of control limits high.
9. LNAPL = Light Non-aqueous Phase Liquid.
10. J = Indicates an estimated value.
GCL
MW-2
MW-1
MW-3
6200B
MW-4
Analytical Method
2L Standard
LNAPL - Not Sampled
TABLE 5
FIELD PARAMETERS
IDC, INC.
2841 HIGHWAY 311
MADISON, ROCKINGHAM COUNTY, NORTH CAROLINA
INCIDENT #37055
Monitoring
Well Date Temperature
(oC)
Dissolved
Oxygen
(mg/L)
Conductivity
(µS/cm)pH (SU)ORP (mV)
2/19/2021
9/22/2021
2/24/2023
MW-2 2/19/2021 16.60 9.25 192 5.47 125.1
MW-3 2/19/2021 17.54 3.17 64 5.27 135.7
MW-4 2/19/2021 16.54 2.28 58 5.45 156.8
Notes:
1. oC = Degrees Celsius.
2. mg/L = milligrams per liter.
3. µs/cm = micro Siemens per centimeter.
4. SU = Standard Units.
5. ORP = Oxidation Reduction Potential.
6. mV = Millivolts.
7. LNAPL = Light Non-aqueous Phase Liquid.
1.50 feet LNAPL - Not Recorded
MW-1
Strong petroleum odor - Not Recorded
Strong petroleum odor - Not Recorded

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

FIGURES

SITE1,500' RADIUS1,000' RADIUS500' RADIUSWSW-8WSW-17WSW-16WSW-15WSW-18WSW-7WSW-6WSW-11WSW-10WSW-9WSW-14WSW-13WSW-23WSW-12WSW-5WSW-4WSW-1WSW-2WSW-3WSW-19WSW-20WSW-22WSW-21

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

APPENDIX A

MMPE REPORT

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

APPENDIX B

WASTE DISPOSAL MANIFEST

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

APPENDIX C

FIELD NOTES

IDC, Inc.

ATC Project No. SLC3705505 NCDEQ State Lead Program

APPENDIX D

SITE PHOTOGRAPHS

Photo 1: Site building. Photo 2: Mobile Multi-Phase Extraction event setup on MW-1.
Site Photographs

IDC, Inc. – Incident #37055

2841 Highway 311
Madison, Rockingham County, North Carolina
2725 E. Millbrook Road, Suite 121
Raleigh, North Carolina
Tel: [phone] Fax: [phone]
Photos Taken By: Laura de Sousa Site ID: Incident #37055 ATC Project No.: SLC3705505

Photo 3: Site area during MMPE. Photo 4: Monitoring well MW-1.
Site Photographs

IDC, Inc. – Incident #37055

2841 Highway 311
Madison, Rockingham County, North Carolina
2725 E. Millbrook Road, Suite 121
Raleigh, North Carolina
Tel: [phone] Fax: [phone]
Photos Taken By: Laura de Sousa Site ID: Incident #37055 ATC Project No.: SLC3705505