RA-2507_15985_CA_MRP_20151130_ATC Letter Report date 1-19-15 - Revised

2725 East Millbrook Rd
Suite 121
Raleigh, NC 27604
Tel: [phone]
Fax: [phone]
www.atcassociates.com
N.C. Engineering License No. C-1598

January 19, 2015

Mr. Mark Petermann
North Carolina Department of Environment and Natural Resources
Division of Waste Management
Underground Storage Tank Section
1637 Mail Service Center
Raleigh, North Carolina 27699-1637

Re: Letter Report
Harold’s Food Mart
117 Old Durham Road
Chapel Hill, Orange County, North Carolina
NCDENR Incident No. 15985
ATC Project No. 45.18514.3080

Dear Mr. Petermann:

ATC Associates of North Carolina, P.C. (ATC) has completed a letter report for the former
Harold’s Food Mart. This report documents a groundwater monitoring well sampling event
conducted at the site on November 7, 2014. The GMR is being performed based on an October 30,
2014 Task Authorization (TA-2) by the Trust Fund Branch of the Underground Storage Tank (UST)
Section, Division of Waste Management, North Carolina Department of Environment and Natural
Resources (NCDENR). The work is performed as part of the State Lead Contract #N14004i
between NCDENR and ATC.

The former Harold’s Food Mart is located at 117 Old Durham Road in Chapel Hill, Orange
County, North Carolina. The site currently contains a single-story building that operates as R&H
Mini-Mart. One monitoring well (MW-1) is associated with the site, and one active water supply
well (WSW-1) is located within 1,000 feet of the site. A groundwater sampling event was
previously conducted at the site on September 10, 2014. Groundwater samples collected from MW-
1 and WSW-1 were analyzed for volatile organic compounds (VOCs). Laboratory analysis of the
groundwater samples collected on September 10, 2014 detected petroleum constituents above
laboratory detection limits in the sample collected from MW-1, but below the 2L Standards.

Letter Report January 19, 2015
Harold’s Food Mart (Incident #15985) ATC Project No. 45.18514.3080
2

During the sampling event in 2011, bis (2-ethylhexyl) phthalate and lead were previously detected
at the site exceeding their respective 2L Standards. Since semi-volatile organic compounds and lead
were not analyzed during the September 10, 2014 event, ATC personnel conducted a second
groundwater sampling event at the site on November 7, 2014. Depth to groundwater was
measured in monitoring well MW-1 at 28.92 feet below ground surface (bgs). The well was then
purged of groundwater, three times its well volume, before the groundwater samples were
collected. The groundwater samples collected from MW-1 were analyzed only for semi-volatile
organics (SVOCs) and lead. Field notes recorded during the sampling event are included in
Appendix A.

Laboratory analytical results of the sampling event indicate that no semi-volatile organic
compounds were detected above method detection limits. Lead was detected in MW-1, above the
laboratory detection limit, but below the 2L Standards. The laboratory results are summarized in the
attached Table.

The laboratory analytical report and chain-of-custody forms are included in Appendix B. As part
of ATC’s quality assurance and quality control (QA and QC) measures, a data review of the
laboratory report was conducted. During the review, it was concluded that samples were
received by the laboratory in acceptable condition and properly preserved. The samples were
analyzed within the correct holding times, and the chain of custody was properly completed by
all parties. The laboratory QC report shows an internal blank was analyzed for each method that
was used for the original samples. The laboratory fortified blank (LFB) and laboratory control
sample (LCS) data results were also provided for each analytical method. Refer to the laboratory
reports in Appendix B for details regarding QA results for the laboratory samples and any noted
exceptions. Overall, ATC concludes that the laboratory results are usable and any exceptions do
not significantly impact the conclusions presented in this report.

Laboratory analytical results from the September 10, 2014 and November 7, 2014 groundwater
sampling events indicate that no petroleum constituent concentrations exceed their respective 2L
standard at the site. ATC recommends abandoning WSW-1 and pursuing site closure.

TABLES
HISTORICAL GROUNDWATER ANALYTICAL RESULTSFORMER HAROLD'S FOOD MART117 OLD DURHAM ROADCHAPEL HILL, ORANGE COUNTY, NORTH CAROLINAINCIDENT #15985ATC PROJECT #45.18514.30806020A VPH VPH VPHNaphthalene (625)Bis(2-Ethylhexyl)phthalat8/3/2011 ND ND ND ND ND ND ND ND 0.65 NA NA11 528.7 J ND ND11/30/2011 ND ND ND ND ND ND ND ND ND NA NA NA NA NA NA NA5/14/2012 ND ND ND ND 1.5 0.48 J ND ND ND NA NA NA NA NA NA NA9/10/2014 <0.079 <0.090 <0.092 <0.18 0.2J <0.18 <0.089 <0.12 <0.08 0.2J NA NA NA NA NA NA11/7/2014 NA NA NA NA NA NA NA NA NA NA <3.6 <4.3 2.3 NA NA NA1 600 600 500 20 70 0.02 6 0.7 400 6 3 15 400 700 2005000 260000 84500 85500 20000 70000 50 6,000 700 28500 6,000 170 15,000 NE NE NENotes:1. MTBE = Methyl Tertiary Butyl Ether2. IPE = Isopropyl Ether3. "<" or ND = Not detected at or above the laboratory detection limit4. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)5. Concentrations in bold equal or exceed the corresponding NCDENR Groundwater Quality 2L Standard (2L Standard)6. GCL = Gross Contamination Limit7. NE = Not established 6251,2,4-TrimethylbenzeneWELL IDDate CollectedBenzeneTolueneAnalytical MethodC9-C22 AromaticsXylenes (Total)MTBEIPETetrachloroethyleneTotal LeadC5-C8 Aliphatics1,2-Dibromoethane (EDB)Naphthalene (6200B)MW-16200B8. J = Indicates constituent was detected above laboratory detection limit but below laboratory reporting limitC9-C18 Aliphatics2L StandardGCLEthylbenzenePage 1 of 1

APPENDIX A

FIELD NOTES

APPENDIX B

LABORATORY ANALYTICAL RESULTS

Page 1 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Table of Contents
Sample Summary 3
Case Narrative 4
Sample Results 5
14K0434-01 5
Sample Preparation Information 8
QC Data 9
Semivolatile Organic Compounds by - GC/MS 9
B109609 9
Metals Analyses (Total) 13
B109468 13
Flag/Qualifier Summary 14
Certifications 15
Chain of Custody/Sample Receipt 17
Page 2 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 3 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 4 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 5 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 6 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 7 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 8 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 9 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 10 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 11 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 12 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 13 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 14 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 15 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 16 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 17 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 18 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 19 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents
Page 20 of 20 14K0434_2 Contest_Final 11 17 14 1608
Table of Contents