B.08 GFI JBCA_TU542_AOC_V_Draft_2022_GWMR_0323.pdf

DRAFT

2022 ANNUAL

GROUNDWATER MONITORING REPORT

AOC V (TU542) SHOPPETTE UST AND DISTRIBUTION LINES, BUILDING 1951

JOINT BASE CHARLESTON-AIR

NORTH CHARLESTON, SOUTH CAROLINA

USEPA FACILITY ID SC3570024460

GWPD SITE # A-10-AA-14727

GWPD SITE # A-10-AA-01827

Performance Based Remediation

Contract Number: FA8903-13-C-0006

Prepared for

AIR FORCE CIVIL ENGINEER CENTER

2261 Hughes Ave., Suite 163

Joint Base San Antonio Lackland, Texas 78236-9853

March 2023

Prepared by:

FPM Remediations, Inc.

An Olgoonik Company

181 Kenwood Avenue Oneida, NY 13421

This page is intentionally left blank.

2022 Annual Groundwater Monitoring Report AOC V (TU542) Shoppette UST and Distribution Lines Joint Base Charleston - Air

FPM Remediations, Inc. i Contract No. FA8903-13-0006

Annual Groundwater Monitoring Report

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

Site:

AOC V (TU542) Shoppette UST and Distribution Lines, Site ID # 14727 Joint Base Charleston-Air North Charleston, South Carolina

Submitted to:

South Carolina Department of Health and Environmental Control (SCDHEC) 2600 Bull Street Columbia, South Carolina 29201

Prepared for:

Joint Base Charleston – Air Charleston, South Carolina

Prepared by:

FPM Remediations, Inc.

181 Kenwood Avenue Oneida, NY 13421

Author:

Justin Damann Title: Site Lead Date:

Reviewer:

Lisa Coffey Title: Project Manager

Gaby Atik, SC PE # 31468 Title: Program Manager

UST Rehabilitation Contractor #446

Laura Powers, PE Title: JBCA Remedial Project Manager

FPM Remediations, Inc. ii Contract No. FA8903-13-0006

FPM Remediations, Inc. iii Contract No. FA8903-13-0006

TABLE OF CONTENTS

SECTION PAGE

1.0 INTRODUCTION.......................................................................................................... 1-1

1.1 Report Organization ..................................................................................................... 1-1

1.2 Facility Information ..................................................................................................... 1-2

1.3 Site Information ........................................................................................................... 1-2

2.0 SITE MONITORING ACTIVITIES ........................................................................... 2-1

2.1 Groundwater Monitoring Program ................................ Error! Bookmark not defined.

2.2 Groundwater Monitoring Procedures .......................................................................... 2-1

2.3 Investigation-Derived Waste (IDW) ............................................................................ 2-1

2.4 Water Level Measurements ......................................................................................... 2-1

2.5 Natural Attenuation Parameter Measurements ............................................................ 2-2

2.6 Groundwater Monitoring Results ................................................................................ 2-2

2.7 Quality Assurance/Quality Control.............................................................................. 2-2

3.0 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS .............................. 3-1

4.0 REFERENCES ............................................................................................................... 4-1

FPM Remediations, Inc. iv Contract No. FA8903-13-0006

TABLES

Table 1 Monitoring Well Screen Details and Groundwater Level Measurements, August

Table 2 Historical and Recent Groundwater/Free Product Measurements, February 2005 to August 2022 Table 3 Historical and Recent Groundwater Geochemical Parameter Measurements, August 2005 to August 2022 Table 4 Groundwater Monitoring Results, August 2022 Table 5 Historical Groundwater Monitoring Results, August 2004 to August 2022

FIGURES

Figure 1 AOC V (TU542) Shoppette UST and Distribution Lines Location Figure 2 Historical Site Features, AOC V (TU542) Shoppette UST and Distribution Lines Figure 3 Groundwater COC Concentrations, August 2022 Figure 4 Historical Detections of Benzene in Groundwater and Water Table Elevations, Monitoring Well MW-5 and -5R February 2005 to August 2022

APPENDICES

Appendix A Groundwater LTM Program SCDHEC Approvals Appendix B Field Notes Appendix C Groundwater Purge Logs Appendix D Laboratory Analytical Report Appendix E Data Validation Report Appendix F SCDHEC Contractor Checklist

FPM Remediations, Inc. v Contract No. FA8903-13-0006

LIST OF ABBREVIATIONS AND ACRONYMS

ACQAP Annual Contractor Quality Assurance Plan AFCEC Air Force Civil Engineer Center AOC Area of Concern ARAR Applicable or Relevant and Appropriate Requirements BTEX Benzene, toluene, ethylbenzene, and xylenes DIPE Diisopropyl ether DO dissolved oxygen DOD Department of Defense ETBA Ethyl-tert-butyl-alcohol ETBE Ethyl-tert-butyl-ether FPM FPM Remediations, Inc.

GWPD Groundwater Protection Division JBCA Joint Base Charleston-Air LTM Long-Term Monitoring MCL Maximum Contaminant Level MS Matrix Spike MSD Matrix Spike Duplicate MTBE Methyl-tert-butyl ether µg/L micrograms per liter NCP National Oil and Hazardous Substances Pollution Contingency Plan (40 CFR 300) NTU nephelometric turbidity unit ORP oxidation-reduction potential OTIE Oneida Total Integrated Enterprises pH negative logarithm of the concentration of Hydrogen (H+) ions in solution QAPP Quality Assurance Project Plan RBSL Risk-Based Screening Level RCRA Resource Conservation and Recovery Act SCDHEC South Carolina Department of Health and Environmental Control SGS SGS Accutest Laboratories, Inc.

SSTL Site-specific Target Level TAA Tert-amyl-alcohol

LIST OF ABBREVIATIONS AND ACRONYMS (continued)

FPM Remediations, Inc. vi Contract No. FA8903-13-0006

TAME Tert-amyl-ether TBA Tert-butyl-alcohol TBF Tert-butyl-formate URS URS Group, Inc.

USEPA United States Environmental Protection Agency UST Underground storage tank VOC Volatile organic compound

FPM Remediations, Inc. 1-1 Contract No. FA8903-13-0006

1.0 INTRODUCTION

FPM Remediations, Inc. (FPM), in association with URS Group, Inc. (URS), under a Performance-Based Remediation (PBR) contract with the Air Force Civil Engineer Center (AFCEC), is conducting environmental remediation activities at the Area of Concern (AOC) V – Shoppette Underground Storage Tank (UST) and Distribution Lines (Charleston Air Force Base Building 1951; Groundwater Protection Division [GWPD] UST Permit #01827; AFCEC Site ID TU542) located at Joint Base Charleston-Air (JBCA) (Figure 1).

The site is regulated under the Resource Conservation and Recovery Act (RCRA), as amended, and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). The site is part of the RCRA Part B Permit SC3 570 024 460, dated July 31, 2019, executed with the South Carolina Department of Health and Environmental Control (SCDHEC), a delegated authority by the United States Environmental Protection Agency (USEPA) for RCRA Corrective Actions.

Because site groundwater contamination came from former petroleum USTs, the site has been delegated by SCDHEC to their UST Division and is subject to SCDHEC UST Division regulations and policies.

Conditional NFA was approved for the Site by SCDHEC in 2019 (SCDHEC, 2019) (Appendix A), and the annual LTM program was suspended. However, due to the failed hydrostatic test of the spill bucket of the premium gasoline UST in June 2020 and the detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) at concentrations above Risk-Based Screening Levels (RBSLs) in a temporary monitoring well installed to investigate the spill bucket, groundwater sampling was completed in 2021 to evaluate site conditions. The groundwater sampling strategy was defined in the 2021 Site-Specific Work Plan (FPM, 2021) and included sampling of six monitoring wells (MW-3, -5A, -5R, -6A, -6S, and -12) for BTEX, naphthalene, and Methyl-tert-butyl ether (MTBE) (USEPA SW846 Method 8260D) and as requested by SCDHEC, all samples were also analyzed for the oxygenates tertamyl-alcohol (TAA), tert-amyl-ether (TAME), tert-butyl-alcohol (TBA), tert-butyl-formate (TBF), ethanol, ethyl-tert-butyl-alcohol (ETBA), ethyl-tert-butyl-ether (ETBE), and diisopropyl ether (DIPE) (USEPA SW-846 Method 8260D oxygenates).

During the March 2021 monitoring event, benzene was the only analyte identified above its RBSL of 5 micrograms per liter (μg/L). Benzene was detected at a concentration of 140 μg/L at MW-5R. Monitoring well MW-5R is the replacement well for MW-5, which historically had elevated concentrations of BTEX, MTBE, naphthalene, and TAA. The benzene concentration at MW-5R was significantly lower than the historical high concentration from MW-5 (33,200 μg/L).

This report presents the results of the Long-Term Monitoring (LTM) groundwater monitoring activities conducted in August 2022. The LTM program was defined in the Annual Contractor Quality Assurance Project Plan (QAPP), SCDHEC UST Programmatic QAPP (FPM, 2022) and the Site-Specific Work Plan (FPM, 2021). Field sampling activities were performed in accordance with the installation Health and Safety Plan (FPM, 2013).

1.1 Report Organization

The report has been organized into the following sections:

Section 1.0 Introduction

FPM Remediations, Inc. 1-2 Contract No. FA8903-13-0006

Section 2.0 Site Monitoring Activities Section 3.0 Summary, Conclusions and Recommendations Section 4.0 References

Relevant maps and illustrations for the site are included in Figures and tabulated data generated for the site are included in Tables. The SCDHEC approval letters for changes made to the LTM program are provided as Appendix A, field logs with equipment calibrations are provided as Appendix B, groundwater purging logs are presented in Appendix C, the laboratory analytical report is included as Appendix D, and the data validation report is presented in Appendix E.

The SCDHEC Contractor Checklist is included as Appendix F.

1.2 Facility Information

JBCA occupies 3,731 acres located approximately 10 miles northwest of the City of Charleston with an approximate population of 5,500. The base population changes periodically as military operations vary from year to year and/or from mission to mission. The facility is highly developed with most land being used for military operations and housing. JBCA is surrounded by industrial, commercial, and residential properties that are part of the City of North Charleston, South Carolina.

1.3 Site Information

The site is located in the western portion of JBCA adjacent to the Dorchester Road entrance.

The Shoppette is an operating convenience store and gas station. Site location and site historical detail maps are provided as Figures 1 and 2, respectively. Groundwater monitoring has been performed at this site since the initial assessment in the early 1990s (Oneida Total Integrated Enterprises [OTIE], 2013).

FPM Remediations, Inc. 2-1 Contract No. FA8903-13-0006

2.0 SITE MONITORING ACTIVITIES

2.1 Groundwater Monitoring

The August 2022 groundwater sampling event included the collection of one groundwater sample at monitoring well MW-5R which was submitted for BTEX, naphthalene and MTBE analysis. Information including sampling time, purge volume, measured field parameters, and general weather conditions are included in the field documentation provided as Appendix B.

Prior to collecting groundwater samples, an oil/water interface probe was used to check for the presence of floating petroleum product. Low-flow purging and groundwater sampling at each monitoring well was performed using a peristaltic pump with dedicated Teflon-lined polyethylene tubing to eliminate the potential for cross-contamination. Sample collection and decontamination procedures followed the SCDHEC-approved Annual Contractor Quality Assurance Plan (ACQAP) (FPM, 2022).

Groundwater temperature, pH, oxidation-reduction potential (ORP), specific conductivity, dissolved oxygen (DO), and turbidity readings were measured via a flow-thru cell and recorded periodically during purging activities. A groundwater sample was collected from the monitoring well after the field parameter readings had stabilized, as documented on the groundwater sampling forms (Appendix C). Stabilization was considered complete when pH varied to within

0.1 standard pH units, specific conductivity varied to within 3 percent, and turbidity remained below 10 Nephelometric Turbidity Units (NTUs) or varied within 10 percent for at least three consecutive measurements (adapted from SCDHEC UST Programmatic QAPP Rev. 2.0 and the USEPA Region 4 groundwater sampling procedures).

Groundwater samples were submitted under an executed chain-of-custody to SGS North America, Inc. (SGS) of Orlando, Florida (formerly Accutest) for analysis. SGS holds Department of Defense (DOD) Environmental Laboratory Approval Program (ELAP) Certification (#L2229) and SCDHEC Certification (#96038001) for the analysis conducted by USEPA SW-846 Method 8260D.

2.2 Investigation-Derived Waste (IDW)

During sampling activities and monitoring well maintenance, purge water and sediment was initially contained in 5-gallon plastic buckets with snap-on lids before being transferred to a temporary holding tank stored at the JBCA Building 692 parking lot. The purge water will be discharged to the JBCA sanitary sewer system following laboratory analysis and approval from the North Charleston Sewer District and JBCA, or it will be disposed at an off-base permitted disposal facility. Other wastes generated during sampling events (i.e., sampling supplies, personal protective equipment, etc.) were disposed of as general refuse.

2.3 Water Level Measurements

Depth to groundwater at monitoring well MW-5R measured 9.33 feet below top of casing (ft BTOC) for the August 2022 sampling round (Table 1). Historical groundwater elevation measurements are presented in Table 2. Groundwater flow direction at the site is easterly in the area downgradient of the USTs (monitoring wells MW-17, -18, and -19), and southeasterly in the immediate vicinity of the USTs (monitoring wells MW-5R and -6S).

FPM Remediations, Inc. 2-2 Contract No. FA8903-13-0006

2.4 Geochemical Measurements

The historical and current field geochemical measurements (temperature, DO, pH, ORP, specific conductivity, and turbidity), and historical natural attenuation parameter measurements (nitrate, sulfate, methane, ferrous iron, carbon dioxide, and alkalinity) are presented in Table 3.

2.5 Groundwater Monitoring Results

Applicable or Relevant and Appropriate Requirement (ARAR) concentrations for groundwater are based on the USEPA National Primary Drinking Water Standards, Maximum Contaminant Levels (MCLs), South Carolina RBSLs, and site-specific target levels (SSTLs). For screening purposes, ARARs are used in the following hierarchy: SCDHEC RBSLs, SSTLs, and USEPA MCLs.

During the August 2022 monitoring event, benzene was the only analyte identified above its RBSL of 5 μg/L. Benzene was detected at a concentration of 31.1 μg/L in groundwater at monitoring well MW-5R. Monitoring well MW-5R is the replacement well for MW-5, which historically had elevated concentrations of BTEX, MTBE, naphthalene, and TAA. The benzene concentration at MW-5R continues to be significantly lower than the historical high concentration from MW-5 (33,200 μg/L).

Toluene, ethylbenzene, xylene, and naphthalene were detected in groundwater at monitoring well MW-5R, but all were below their respective SCDHEC RBSLs. The SCDHEC RBSL for toluene is 1,000 μg/L, and groundwater at MW-5R had a concentration of 1.4 B μg/L during the August 2022 event. The SCDHEC RBSL for ethylbenzene is 700 μg/L and groundwater at MW-5R had a concentration of 29.0 μg/L. The SCDHEC RBSL for xylene is 10,000 μg/L and groundwater at MW-5R had a concentration of 4.2 μg/L. The SCDHEC RBSL for naphthalene is 25 μg/L and groundwater at MW-5R had a concentration of 2.8 J μg/L.

As reported in the previous LTM reports, toluene, ethylbenzene, xylene, and naphthalene concentrations in groundwater at MW-5R are significantly lower than the historical high concentrations in groundwater at MW-5 (99,000 μg/L, 4,900 μg/L, 23,100 μg/L, and 176 μg/L, respectively). MTBE was non-detect at monitoring well MW-5R in August 2022.

Laboratory analytical results for the August 2022 groundwater monitoring are provided in Table 4 and the current benzene results are illustrated on Figure 3. Historical groundwater analytical results are summarized in Table 5, and the historical benzene trends are shown on Figure 4.

2.6 Quality Assurance/Quality Control

Trip blanks (TB20220811 and TB20220811A) were included in the coolers containing the volatile organic compound (VOC) samples, and equipment blank (EB20220811) was collected at the end of the sample day. Other QA/QC samples were collected as part of the larger sample set for the entire August 2022 sampling event at all sites at JBCA. The August 2022 sampling event consisted of all JBCA sites sampled quarterly and was performed at the same time in one mobilization.

The samples were stored in ice-filled coolers immediately after collection to maintain temperature criteria (4 ±2 degrees Celsius). The custody seals were applied to the coolers, and the coolers were shipped overnight to the analytical laboratory (SGS). Upon receipt, the

FPM Remediations, Inc. 2-3 Contract No. FA8903-13-0006 laboratory confirmed the custody seals were present and intact, and the temperature criteria were achieved.

Data validation was performed in accordance with the Uniform Federal Policy-QAPP by the project chemist. Holding times, preservation methods, surrogate recoveries, laboratory control sample recoveries, matrix spike/matrix spike duplicate (MS/MSD) recoveries, method blanks, equipment blanks, trip blanks, field duplicates, instrument tuning, internal standards, and calibrations were reviewed. Any identified deficiencies and their respective corrective actions are provided in the data validation report (Table I, Appendix E). 100% of the sample results are deemed acceptable for their intended use. An electronic copy of the laboratory analytical data for this monitoring period is included in Appendix D and the data validation report is included in Appendix E.

FPM Remediations, Inc. 2-4 Contract No. FA8903-13-0006

FPM Remediations, Inc. 3-1 Contract No. FA8903-13-0006

3.0 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

Conditional NFA was approved for the Site by SCDHEC in 2019 and the annual LTM program was suspended. As a result of a failed hydrostatic test of a spill bucket at a UST in June 2020, one round of groundwater sampling was conducted in 2021 at six monitoring wells for BTEX, naphthalene, MTBE, and oxygenates. The results show that benzene was the only analyte identified above its RBSL at a concentration of 140 μg/L at monitoring well MW-5R only.

In August 2022, the groundwater sampling included monitoring well MW-5R with analysis for BTEX, naphthalene and MTBE. The groundwater elevation recorded at monitoring well MW-5 in August 2022 was in line with historical groundwater elevations measured at this well.

Benzene is the only remaining COC that exceeds its RBSL in groundwater; its concentration in August 2022 (31.0 μg/L was significantly lower than the 2021 concentration (140 μg/L).

Concentrations of site COCs in groundwater in the former UST area continue to be significantly lower than historical concentrations.

FPM Remediations, Inc. 3-2 Contract No. FA8903-13-0006

FPM Remediations, Inc. 4-1 Contract No. FA8903-13-0006

4.0 REFERENCES

FPM, 2013. Health and Safety Plan for Performance-Based Remediation at JB CHS-Air, September.

FPM, 2015. Draft Final Semi-Annual Groundwater Monitoring Report (January 2015 through

June 2015) AOC V (TU542) Shoppette UST and Distribution Lines, Joint Base Charleston-Air. August.

FPM, 2021. Draft Final 2021 Site-Specific Work Plan for Approved Annual Contractor Quality Assurance Plan, AOC V (TU542), January.

FPM, 2022. Annual Contractor Quality Assurance Project Plan (QAPP), SCDHEC UST Programmatic QAPP. February.

OTIE, 2013. Draft Final Semi-Annual (July to December 2013) Groundwater Monitoring Report, AAFES Shoppette Facility (UST Permit #14727) Joint Base Charleston-Air, Charleston, South Carolina. December 18.

SCDHEC, 2015. Approval letter for Draft Final 2015 Semi-Annual Groundwater Monitoring Report received August 20, 2015. Dated August 27, 2015.

SCDHEC, 2019. Approval letter Re: Conditional No Further Action at AOC V, TU542, AAFES Shoppette, Joint Base Charleston-Air. Dated June 4, 2019.

FPM Remediations, Inc. Contract No. FA8903-13-0006

TABLES

Table 1 Monitoring Well Construction Details and Groundwater Level Measurements

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina

Depth to Groundwater

(feet btoc)

Groundwater Elevation (feet amsl)

MW-2 386,466.9995 2,286,013.2148 12.81 3-13 36.77 NM NM

MW-3 386,497.9214 2,285,974.9006 26.90 24-29 37.80 NM NM

MW-5A 386,387.2131 2,285,950.5345 12.01 2-12 34.42 NM NM

MW-5R 386,458.2310 2,285,928.2140 16.06 6-16 36.32 9.33 26.99

MW-6A 386,406.7108 2,285,887.0535 26.80 21-26 35.92 NM NM

MW-6S 386,399.0952 2,285,901.4069 11.65 2-12 34.51 NM NM

MW-7 386,400.1553 2,285,879.7704 13.85 4-14 35.70 NM NM

MW-8R 386,344.6200 2,285,860.9000 5.96 5-15 33.43 NM NM

MW-12 386,402.1552 2,285,813.1229 7.16 NA 35.40 NM NM

MW-17 386,663.4456 2,286,006.4568 19.41 11-21 37.76 NM NM

MW-18 386,613.5548 2,285,995.8778 12.75 10-20 37.94 NM NM

MW-19 386,559.1063 2,286,020.2867 20.05 10-20 37.77 NM NM

MW-20 386,601.8036 2,285,941.9034 19.90 10-20 38.28 NM NM

Notes:

amsl – above mean sea level bls – below land surface BTOC – below top of casing NA – Not available NM – Not measured a Total well depths measured on August 9, 2022 b Top of casing elevations (feet above mean sea level) were provided by Joint Base Charleston-Air.

All monitoring wells were constructed with 10 foot screens, with the exception of MW-3 and MW-6A, which have 5 foot screens.

Top of Casing Elevationb

(feet amsl)

August 9, 2022 Well

Identification Number

Northing Easting Measured

Well Deptha

(feet btoc)

Screened Interval (feet bls)

Table 2 Historical and Recent Groundwater/Free Product Measurements

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina February 2005 to August 2022

Monitoring Well

Total Depth of Well

(ft)

Top of Casing

Elevation1

(ft amsl)

Date Measured

Depth to Water

(ft BTOC)

Depth to Free Product

(ft BTOC)

Free Product

Thickness (ft)

Groundwater Elevation (ft amsl)

5/4/2012 12.39 NP 0.00 24.38

4/16/2013 8.97 NP 0.00 27.80

10/22/2013 10.05 NP 0.00 26.72

2/26/2014 10.21 NP 0.00 26.56

10/14/2014 9.61 NP 0.00 27.16

3/17/2015 8.19 NP 0.00 28.58

9/29/2015 9.25 NP 0.00 27.52

3/3/2016 6.71 NP 0.00 30.06

2/23/2017 8.85 NP 0.00 27.92

3/11/2018 9.84 NP 0.00 26.93

3/20/2021 7.07 NP 0.00 29.70

2/15/2005 13.10 NP 0.00 24.70

8/16/2005 12.42 NP 0.00 25.38

2/8/2006 11.56 NP 0.00 26.24

9/13/2006 12.26 NP 0.00 25.54

3/21/2007 11.87 NP 0.00 25.93

10/24/2007 12.81 NP 0.00 24.99

11/6/2008 11.75 NP 0.00 26.05

12/8/2009 11.90 NP 0.00 25.90

2/14/2011 11.49 NP 0.00 26.31

5/3/2012 13.59 NP 0.00 24.21

4/16/2013 10.50 NP 0.00 27.30

10/22/2013 11.37 NP 0.00 26.43

2/27/2014 11.52 NP 0.00 26.28

10/14/2014 11.02 NP 0.00 26.78

3/17/2015 9.81 NP 0.00 27.99

9/29/2015 10.60 NP 0.00 27.20

3/3/2016 8.16 NP 0.00 29.64

2/23/2017 10.21 NP 0.00 27.59

3/11/2018 11.12 NP 0.00 26.68

3/20/2021 8.70 NP 0.00 29.10

2/15/2005 NM NM NM NM

8/16/2005 11.74 NP 0.00 25.69

2/8/2006 11.04 NP 0.00 26.39

9/13/2006 11.54 NP 0.00 25.89

3/21/2007 11.35 NP 0.00 26.08

10/24/2007 Dry NM NM NM

11/6/2008 11.05 NP 0.00 26.38

12/8/2009 11.27 NP 0.00 26.16

2/14/2011 11.08 NP 0.00 26.35

3/31/2011 11.40 NP 0.00 26.03

5/3/2012 12.04 NP 0.00 25.39

4/16/2013 10.40 10.16 0.24 27.03

3/3/2016 5.40 NP 0.00 29.02

2/23/2017 7.45 NP 0.00 26.97

3/11/2018 8.52 NP 0.00 25.90

3/20/2021 5.75 NP 0.00 28.67

36.77

MW-3 26.95 37.80

MW-5A 12.05 34.42

MW-5 12.32 37.43

MW-2 12.92

Abandoned well

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina February 2005 to August 2022

Monitoring Well

Total Depth of Well

(ft)

Top of Casing

Elevation1

(ft amsl)

Date Measured

Depth to Water

(ft BTOC)

Depth to Free Product

(ft BTOC)

Free Product

Thickness (ft)

Groundwater Elevation (ft amsl)

10/23/2013 10.66 NP 0.00 25.66

2/26/2014 10.94 NP 0.00 25.38

10/15/2014 10.34 NP 0.00 25.98

3/17/2015 9.05 NP 0.00 27.27

9/30/2015 9.95 NP 0.00 26.37

3/3/2016 7.41 NP 0.00 28.91

2/23/2017 9.54 NP 0.00 26.78

3/11/2018 10.82 NP 0.00 25.50

3/20/2021 7.89 NP 0.00 28.43

8/9/2022 9.33 NP 0.00 26.99

2/15/2005 11.63 NP 0.00 24.29

8/16/2005 10.64 NP 0.00 25.28

2/8/2006 9.90 NP 0.00 26.02

9/13/2006 10.22 NP 0.00 25.70

3/21/2007 10.00 NP 0.00 25.92

10/24/2007 10.85 NP 0.00 25.07

11/6/2008 11.53 NP 0.00 24.39

12/8/2009 9.83 NP 0.00 26.09

2/14/2011 9.42 NP 0.00 26.50

5/3/2012 11.60 NP 0.00 24.32

4/16/2013 8.78 NP 0.00 27.14

10/23/2013 9.21 NP 0.00 26.71

2/27/2014 9.74 NP 0.00 26.18

10/14/2014 9.33 NP 0.00 26.59

3/17/2015 8.11 NP 0.00 27.81

9/30/2015 8.2 NP 0.00 27.72

3/3/2016 5.73 NP 0.00 30.19

2/23/2017 7.85 NP 0.00 28.07

3/13/2018 9.48 NP 0.00 26.44

3/20/2021 7.35 NP 0.00 28.57

3/3/2016 5.43 NP 0.00 29.08

2/23/2017 8.56 NP 0.00 25.95

3/11/2018 8.69 NP 0.00 25.82

3/20/2021 5.85 NP 0.00 28.66

2/15/2005 8.70 NP 0.00 25.45

8/17/2005 7.83 NP 0.00 26.32

2/8/2006 6.49 NP 0.00 27.66

9/13/2006 6.70 NP 0.00 27.45

3/21/2007 7.32 NP 0.00 26.83

10/24/2007 7.70 NP 0.00 26.45

11/6/2008 6.08 NP 0.00 28.07

12/8/2009 6.80 NP 0.00 27.35

2/14/2011 6.54 NP 0.00 27.61

5/4/2012 Abandoned well

MW-8 12.85 34.13

MW-5R 16.18 36.32

MW-6A 26.76 35.92

11.98MW-6S 34.51

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina February 2005 to August 2022

Monitoring Well

Total Depth of Well

(ft)

Top of Casing

Elevation1

(ft amsl)

Date Measured

Depth to Water

(ft BTOC)

Depth to Free Product

(ft BTOC)

Free Product

Thickness (ft)

Groundwater Elevation (ft amsl)

6/11/2012 9.75 NP 0.00 23.68

4/16/2013 5.20 NP 0.00 28.23

10/23/2013 7.12 NP 0.00 26.31

2/26/2014 7.45 NP 0.00 25.98

10/14/2014 6.64 NP 0.00 26.79

3/17/2015 5.14 NP 0.00 28.29

9/30/2015 6.17 NP 0.00 27.26

3/3/2016 3.79 NP 0.00 29.64

2/23/2017 5.86 NP 0.00 27.57

3/11/2018 7.07 NP 0.00 26.36

3/20/2021 4.07 NP 0.00 29.36

2/15/2005 10.44 NP 0.00 24.96

8/16/2005 9.72 NP 0.00 25.68

2/8/2006 5.64 NP 0.00 29.76

9/13/2006 9.16 NP 0.00 26.24

3/21/2007 9.27 NP 0.00 26.13

10/24/2007 10.05 NP 0.00 25.35

11/6/2008 8.52 NP 0.00 26.88

12/8/2009 8.95 NP 0.00 26.45

2/14/2011 8.39 NP 0.00 27.01

5/3/2012 11.15 NP 0.00 24.25

4/16/2013 7.24 NP 0.00 28.16

10/22/2013 8.79 NP 0.00 26.61

2/26/2014 9.01 NP 0.00 26.39

10/14/2014 8.40 NP 0.00 27.00

3/17/2015 6.98 NP 0.00 28.42

9/30/2015 7.92 NP 0.00 27.48

3/3/2016 5.30 NP 0.00 30.10

2/23/2017 7.53 NP 0.00 27.87

3/11/2018 8.74 NP 0.00 26.66

3/20/2021 5.68 NP 0.00 29.72

3/23/2005 13.26 NP 0.00 24.50

8/16/2005 13.13 NP 0.00 24.63

2/8/2006 12.71 NP 0.00 25.05

9/13/2006 13.48 NP 0.00 24.28

3/21/2007 12.85 NP 0.00 24.91

10/24/2007 13.81 NP 0.00 23.95

11/6/2008 13.31 NP 0.00 24.45

12/8/2009 13.07 NP 0.00 24.69

2/14/2011 12.72 NP 0.00 25.04

5/4/2012 14.30 NP 0.00 23.46

4/16/2013 11.82 NP 0.00 25.94

10/23/2013 12.09 NP 0.00 25.67

2/26/2014 12.40 NP 0.00 25.36

10/14/2014 11.62 NP 0.00 26.14

3/18/2015 10.57 NP 0.00 27.19

9/29/2015 11.38 NP 0.00 26.38

3/3/2016 8.92 NP 0.00 28.84

2/23/2017 10.85 NP 0.00 26.91

3/11/2018 11.81 NP 0.00 25.95

3/20/2021 9.25 NP 0.00 28.51

MW-8R 15.03 33.43

MW-17 19.81 37.76

14.68 35.40MW-12

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina February 2005 to August 2022

Monitoring Well

Total Depth of Well

(ft)

Top of Casing

Elevation1

(ft amsl)

Date Measured

Depth to Water

(ft BTOC)

Depth to Free Product

(ft BTOC)

Free Product

Thickness (ft)

Groundwater Elevation (ft amsl)

3/23/2005 13.38 NP 0.00 24.56

8/16/2005 16.20 NP 0.00 21.74

2/8/2006 13.38 NP 0.00 24.56

9/13/2006 14.12 NP 0.00 23.82

3/21/2007 13.52 NP 0.00 24.42

10/24/2007 14.47 NP 0.00 23.47

11/6/2008 13.90 NP 0.00 24.04

12/8/2009 13.68 NP 0.00 24.26

2/14/2011 13.45 NP 0.00 24.49

5/4/2012 15.01 NP 0.00 22.93

4/16/2013 12.53 NP 0.00 25.41

10/22/2013 12.74 NP 0.00 25.20

2/26/2014 13.09 NP 0.00 24.85

10/15/2014 12.40 NP 0.00 25.54

3/17/2015 11.24 NP 0.00 26.70

9/29/2015 12.11 NP 0.00 25.83

3/3/2016 9.56 NP 0.00 28.38

2/23/2017 11.56 NP 0.00 26.38

3/11/2018 12.55 NP 0.00 25.39

3/20/2021 10.01 NP 0.00 27.93

3/23/2005 13.12 NP 0.00 24.65

8/16/2005 12.35 NP 0.00 25.42

2/8/2006 11.80 NP 0.00 25.97

9/13/2006 12.50 NP 0.00 25.27

3/21/2007 11.97 NP 0.00 25.80

10/24/2007 12.91 NP 0.00 24.86

11/6/2008 12.20 NP 0.00 25.57

12/8/2009 12.08 NP 0.00 25.69

2/14/2011 11.90 NP 0.00 25.87

5/4/2012 13.56 NP 0.00 24.21

4/16/2013 10.92 NP 0.00 26.85

10/22/2013 11.22 NP 0.00 26.55

2/26/2014 11.57 NP 0.00 26.20

10/14/2014 10.91 NP 0.00 26.86

3/17/2015 9.74 NP 0.00 28.03

9/29/2015 10.80 NP 0.00 26.97

3/3/2016 8.03 NP 0.00 29.74

2/23/2017 10.11 NP 0.00 27.66

3/11/2018 11.11 NP 0.00 26.66

3/20/2021 8.46 NP 0.00 29.31

20.20 37.94

MW-19 20.12 37.77

MW-18

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina February 2005 to August 2022

Monitoring Well

Total Depth of Well

(ft)

Top of Casing

Elevation1

(ft amsl)

Date Measured

Depth to Water

(ft BTOC)

Depth to Free Product

(ft BTOC)

Free Product

Thickness (ft)

Groundwater Elevation (ft amsl)

3/23/2005 13.60 NP 0.00 24.68

8/16/2005 12.94 NP 0.00 25.34

2/8/2006 12.55 NP 0.00 25.73

9/13/2006 13.21 NP 0.00 25.07

3/21/2007 12.71 NP 0.00 25.57

10/24/2007 13.59 NP 0.00 24.69

11/6/2008 13.04 NP 0.00 25.24

12/8/2009 12.86 NP 0.00 25.42

2/14/2011 12.55 NP 0.00 25.73

5/3/2012 13.11 NP 0.00 25.17

4/16/2013 11.83 NP 0.00 26.45

10/23/2013 11.86 NP 0.00 26.42

2/26/2014 12.25 NP 0.00 26.03

10/14/2014 11.54 NP 0.00 26.74

3/18/2015 10.62 NP 0.00 27.66

9/29/2015 11.22 NP 0.00 27.06

3/3/2016 8.82 NP 0.00 29.46

2/23/2017 10.76 NP 0.00 27.52

3/11/2018 11.73 NP 0.00 26.55

3/20/2021 9.23 NP 0.00 29.05

Notes:

amsl = above mean sea level BTOC - below top of casing ft = feet NM - not measured NP - not present 1 Top of casing elevation provided by Joint Base Charleston-Air.

All monitoring wells were constructed with 10 foot screens, with the exception of MW- 3 and MW-6A, which have 5 foot screens.

MW-20 20.04 38.28

Table 3 Historical and Recent Geochemical Parameter Measurements

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina August 2005 to August 2022

Well Identification

Number (relative position to the source)

Date Sampled

Temperature (°C)

Dissolved Oxygen* (mg/L) pH

(SU)

ORP

(mV)

Specific Conductivity

(mS/cm)

Turbidity

(NTU)

Alkalinity (mg/L)

Carbon Dioxide (mg/L)

Ferrous Iron (mg/L)

Nitrogen/ Nitrate (mg/L)

Sulfate (mg/L)

Methane (μg/L) Note

8/16/2005 23.00 3.32 4.85 NM 0.110 0.00 NM NM NM NM NM NM

2/8/2006 18.50 5.81 4.67 NM 0.129 >999 NM NM NM NM NM NM

9/13/2006 23.10 4.20 4.68 NM 0.185 717.00 NM NM NM NM NM NM

3/21/2007 18.10 4.48 4.10 NM 0.122 47.00 NM NM NM NM NM NM

10/23/2013 21.91 2.76 4.22 174.4 0.205 0.27 NM NM NM NM NM NM clear, no odor 2/26/2014 16.53 8.49 4.73 244.0 0.101 6.34 NM NM NM NM NM NM clear, no odor

10/14/2014 24.90 3.29 4.62 330.2 0.158 0.37 NM NM NM NM NM NM clear, no odor 3/17/2015 18.40 3.71 4.59 356.0 0.124 2.48 NM NM NM NM NM NM clear, no odor 9/29/2015 25.30 2.39 3.87 360.7 0.114 0.92 NM NM NM NM NM NM clear, no odor 3/10/2016 20.70 5.00 6.10 176.3 0.149 4.97 NM NM NM NM NM NM clear, no odor 2/24/2017 18.70 5.93 5.67 179.40 0.093 2.93 NM NM NM NM NM NM clear, no odor

8/16/2005 22.20 10.39 6.54 NM 0.394 17.60 NM NM NM NM NM NM

2/8/2006 21.20 8.51 6.96 NM 0.482 10.00 NM NM NM NM NM NM

9/13/2006 22.00 4.59 6.77 NM 0.381 53.00 NM NM NM NM NM NM

3/22/2007 21.70 2.36 6.54 NM 0.310 16.00 NM NM NM NM NM NM

10/25/2007 22.30 2.27 6.39 NM 0.396 6.00 NM NM NM NM NM NM

11/7/2008 22.30 3.78 6.55 137 0.460 19.90 NM NM NM NM NM NM

12/8/2009 22.00 1.98 6.65 123 0.348 7.03 NM NM NM NM NM NM clear, no odor

2/14/2011 20.78 5.41 6.82 138 0.169 2.60 NM NM NM NM NM NM

10/23/2013 21.88 2.48 5.70 126 0.096 0.99 NM NM NM NM NM NM clear, no odor 2/27/2014 18.50 6.06 6.20 126 0.347 7.55 NM NM NM NM NM NM clear, no odor

10/14/2014 24.50 0.35 6.70 83.4 0.306 4.38 NM NM NM NM NM NM clear, no odor 3/17/2015 25.23 0.00 6.65 40.0 0.256 3.86 NM NM NM NM NM NM clear, no odor

9/29/2015 24.60 0.62 6.69 22.9 0.310 2.18 NM NM NM NM NM NM clear, brown floc, slight sulfur odor

3/10/2016 22.90 6.77 7.02 -98.7 0.550 3.47 NM NM NM NM NM NM clear, no odor 2/24/2017 21.60 2.23 6.94 90.6 0.284 0.69 NM NM NM NM NM NM clear, no odor 3/12/2018 17.50 5.93 6.74 87.7 0.280 5.27 NM NM NM NM NM NM clear, no odor 3/20/2021 21.29 2.23 6.90 19.6 0.230 0.40 NM NM NM NM NM NM cloudy/brown

2/8/2006 20.50 3.11 6.76 NM 0.097 63.00 NM NM NM NM NM NM

9/13/2006 26.60 3..06 6.47 NM 0.600 262.00 NM NM NM NM NM NM

3/22/2007 20.10 2.92 6.52 NM 0.647 26.00 NM NM NM NM NM NM

12/8/2009 20.20 0.59 6.60 152 0.458 0.69 NM NM NM NM NM NM clear

2/14/2011 20.83 0.62 6.53 -140 0.639 1.50 NM NM NM NM NM NM

3/31/2011 18.10 9.30 6.39 NM 0.455 17.00 NM NM NM NM NM NM

3/10/2016 21.90 6.92 7.23 122 0.570 6.55 NM NM NM NM NM NM clear, no odor 2/23/2017 23.20 7.82 7.92 136 0.500 26.10 NM NM NM NM NM NM clear, no odor 3/12/2018 16.40 1.69 6.28 156 0.660 65.40 NM NM NM NM NM NM purged dry 3/20/2021 21.03 0.68 6.97 15.7 0.550 1.5 NM NM NM NM NM NM clear, no odor

10/23/2013 22.67 1.01 6.39 48.6 0.814 69.30 NM NM NM NM NM NM cloudy, fuel odor 2/27/2014 19.17 3.19 6.33 -103.0 0.639 8.09 NM NM NM NM NM NM clear, strong fuel odor

10/15/2014 25.90 0.36 6.43 -135.6 0.690 10.36 NM NM NM NM NM NM clear, strong petro odor 3/17/2015 23.42 0.00 6.46 -159.0 0.608 8.01 NM NM NM NM NM NM clear, strong petro odor

9/30/2015 26.10 1.12 6.24 47.5 0.660 6.76 NM NM NM NM NM NM clear, black floc, strong petro odor

3/10/2016 22.70 5.29 6.91 -125.4 0.680 8.6 NM NM NM NM NM NM clear, strong petro odor 2/23/2017 22.30 3.02 6.85 -68.7 0.710 14.4 NM NM NM NM NM NM grey, fuel odor 3/11/2018 21.00 6.52 6.80 -121.8 0.930 16.8 NM NM NM NM NM NM clear, petro odor 3/20/2021 24.39 0.06 6.77 -72.3 0.550 11.1 NM NM NM NM NM NM cloudy, fuel odor 8/9/2022 30.29 0.01 6.57 -47.0 0.355 56.5 NM NM NM NM NM NM clear, strong fuel odor

MW-5

(Directly

Downgradient)

MW-2

(Cross-gradient)

MW-5R

(Directly

Downgradient)

MW-5A

(Downgradient)

MW-3

(Cross-gradient)

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina August 2005 to August 2022

Well Identification

Number (relative position to the source)

Date Sampled

Temperature (°C)

Dissolved Oxygen* (mg/L) pH

(SU)

ORP

(mV)

Specific Conductivity

(mS/cm)

Turbidity

(NTU)

Alkalinity (mg/L)

Carbon Dioxide (mg/L)

Ferrous Iron (mg/L)

Nitrogen/ Nitrate (mg/L)

Sulfate (mg/L)

Methane (μg/L) Note

8/17/2005 23.20 4.45 6.15 NM 0.195 >999 NM NM NM NM NM NM

2/8/2006 18.80 4.90 6.35 NM 0.267 466.00 NM NM NM NM NM NM

9/13/2006 23.50 3.69 6.21 NM 2.690 160.00 NM NM NM NM NM NM

3/21/2007 18.00 4.23 5.76 NM 0.235 91.00 NM NM NM NM NM NM

8/16/2005 21.90 10.15 2.39 NM 0.075 478.00 NM NM NM NM NM NM

2/8/2006 20.10 2.28 6.36 NM 0.098 463.00 NM NM NM NM NM NM

9/13/2006 21.10 5.40 6.24 NM 0.082 221.00 NM NM NM NM NM NM

3/22/2007 21.00 2.94 6.05 NM 0.075 46.00 NM NM NM NM NM NM

10/25/2007 22.00 4.59 6.12 145.0 0.094 74.80 NM NM NM NM NM NM

11/7/2008 22.00 6.56 5.96 218.8 0.084 79.00 NM NM NM NM NM NM

12/8/2009 20.30 4.50 5.86 121.1 0.050 29.30 NM NM NM NM NM NM clear, no odor

2/14/2011 19.90 3.45 5.94 203.0 0.079 6.90 NM NM NM NM NM NM

10/22/2013 21.86 4.04 4.81 115.3 0.047 1.72 NM NM NM NM NM NM clear, no odor 2/27/2014 18.08 6.48 6.06 154.0 0.072 6.28 NM NM NM NM NM NM slight odor

10/14/2014 23.20 3.97 5.84 225.5 0.054 0.63 NM NM NM NM NM NM clear, no odor 3/17/2015 21.20 3.51 5.69 247.6 0.057 3.87 NM NM NM NM NM NM clear, no odor 9/30/2015 24.30 0.32 5.12 29.6 0.076 7.16 NM NM NM NM NM NM cloudy, septic odor 3/13/2018 19.50 2.67 5.67 57.5 0.092 3.16 NM NM NM NM NM NM clear, no odor 3/20/2021 18.34 2.73 5.98 192.6 0.060 0.10 NM NM NM NM NM NM clear, no odor

3/10/2016 21.10 5.77 6.84 20.8 0.840 12.10 NM NM NM NM NM NM

2/23/2017 22.30 3.30 7.04 10.8 0.540 5.86 NM NM NM NM NM NM clear, no odor 3/20/2021 21.04 0.93 6.85 168.6 0.920 2.48 NM NM NM NM NM NM clear, no odor

8/16/2005 22.75 5.60 5.59 NM 0.057 530.00 NM NM NM NM NM NM

2/8/2006 19.50 3.01 5.67 NM 0.048 483.00 NM NM NM NM NM NM

9/13/2006 22.50 2.92 5.59 NM 0.062 234.00 NM NM NM NM NM NM

3/21/2007 18.80 3.16 5.28 NM 0.048 10.00 NM NM NM NM NM NM

8/17/2005 24.40 4.10 6.09 NM 0.030 >999 NM NM NM NM NM NM

2/8/2006 16.80 5.75 6.34 NM 0.049 362.00 NM NM NM NM NM NM

9/13/2006 25.20 2.98 6.19 NM 0.046 146.00 NM NM NM NM NM NM

3/21/2007 17.40 5.58 6.20 NM 0.093 40.00 NM NM NM NM NM NM

10/25/2007 24.40 6.70 6.70 NM 0.117 35.70 NM NM NM NM NM NM

11/7/2008 21.58 8.52 6.38 164 0.090 148.20 NM NM NM NM NM NM

12/8/2009 20.60 7.29 7.10 109 0.123 8.40 NM NM NM NM NM NM clear, no odor

2/14/2011 17.69 7.21 6.73 156 0.105 18.30 NM NM NM NM NM NM

10/22/2013 23.36 4.99 5.58 88.3 0.137 69.3 NM NM NM NM NM NM cloudy, no odor 2/26/2014 17.68 7.20 5.93 167.0 0.071 52.0 NM NM NM NM NM NM clear, no odor

10/14/2014 26.20 5.55 6.26 188.8 0.055 64.3 NM NM NM NM NM NM cloudy, no odor 3/17/2015 18.50 8.08 6.45 167.7 0.057 120.0 NM NM NM NM NM NM cloudy, no odor 9/30/2015 27.80 2.93 6.20 159.4 0.071 57.0 NM NM NM NM NM NM cloudy, no odor 3/10/2016 19.00 8.29 6.55 125.6 0.048 99.7 NM NM NM NM NM NM cloudy, no odor 2/23/2017 24.10 5.93 6.46 163.0 0.039 59.4 NM NM NM NM NM NM cloudy, no odor

MW-8R

(Downgradient)

MW-8

(Downgradient)

MW-7

(Downgradient)

MW-6A

(Downgradient)

MW-6

(Downgradient)

MW-6S

(Downgradient)

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina August 2005 to August 2022

Well Identification

Number (relative position to the source)

Date Sampled

Temperature (°C)

Dissolved Oxygen* (mg/L) pH

(SU)

ORP

(mV)

Specific Conductivity

(mS/cm)

Turbidity

(NTU)

Alkalinity (mg/L)

Carbon Dioxide (mg/L)

Ferrous Iron (mg/L)

Nitrogen/ Nitrate (mg/L)

Sulfate (mg/L)

Methane (μg/L) Note

8/16/2005 21.18 4.00 5.13 NM 0.038 830.10 NM NM NM NM NM NM

2/8/2006 18.50 3.32 5.41 NM 0.850 95.00 NM NM NM NM NM NM

9/13/2006 22.00 3.54 5.42 NM 0.058 231.00 NM NM NM NM NM NM

3/22/2007 17.90 4.28 4.51 NM 0.064 25.00 NM NM NM NM NM NM

8/16/2005 21.48 1.75 4.96 NM 0.028 368.00 NM NM NM NM NM NM

2/8/2006 18.80 2.56 5.01 NM 0.037 802.00 NM NM NM NM NM NM

9/13/2006 22.50 3.08 4.93 NM 0.037 86.00 NM NM NM NM NM NM

3/21/2007 17.80 1.77 4.54 NM 0.036 41.00 NM NM NM NM NM NM

10/25/2007 23.20 2.77 4.89 NM 0.048 43.90 NM NM NM NM NM NM

11/7/2008 22.10 3.58 4.72 186 0.156 10.80 NM NM NM NM NM NM

12/8/2009 19.90 1.04 4.90 275 0.165 8.30 NM NM NM NM NM NM

2/14/2011 16.96 0.67 5.08 -67 0.190 16.50 NM NM NM NM NM NM

10/22/2013 21.97 0.54 5.38 -37 0.316 59.90 NM NM NM NM NM NM cloudy, sulfur smell

2/26/2014 16.10 2.94 5.12 114 0.219 92.20 NM NM NM NM NM NM

10/14/2014 23.40 0.23 5.59 -43 0.221 10.30 NM NM NM NM NM NM cloudy, sulfur smell 3/17/2015 18.90 0.86 5.37 206 0.311 82.60 NM NM NM NM NM NM cloudy, no odor

9/30/2015 24.80 0.72 5.02 -18 0.233 6.20 NM NM NM NM NM NM clear, orange floc, sulfur odor

3/10/2016 19.70 5.73 5.17 124 0.081 59.00 NM NM NM NM NM NM cloudy, no odor

2/23/2017 21.80 5.56 6.31 -56 0.268 39.70 NM NM NM NM NM NM cloudy, slight sulfur odor

3/11/2018 19.00 5.10 5.56 -88 0.250 30.50 NM NM NM NM NM NM cloudy, sulfur odor 3/20/2021 18.04 2.84 5.46 191.5 0.110 71.3 NM NM NM NM NM NM brown, no odor

8/16/2005 21.90 4.46 4.18 NM 0.070 50.00 NM NM NM NM NM NM

2/8/2006 19.60 2.26 4.83 NM 0.061 252.00 NM NM NM NM NM NM

3/21/2007 19.20 1.69 4.67 NM 0.053 44.00 NM NM NM NM NM NM

8/16/2005 26.90 8.97 4.75 NM 0.033 364.00 NM NM NM NM NM NM

2/8/2006 23.80 1.93 5.07 NM 0.039 944.00 NM NM NM NM NM NM

9/13/2006 26.50 2.40 4.98 NM 0.048 >999 NM NM NM NM NM NM

3/22/2007 22.70 2.10 4.88 NM 0.071 475.00 NM NM NM NM NM NM

8/16/2005 24.90 7–8 4.90 230 0.073 69.10 > 1000 15.5 0.0 0.26 < 1 3.11 2/8/2006 22.23 5.1 4.62 260.1 0.10 -4.40 40.0 27.0 0.0 0.22 8.4 < 0.50

9/13/2006 25.16 2.0 4.81 222.6 0.09 1.70 < 10 42.0 0.0 0.29 < 1 < 26 3/21/2007 21.00 2.1 4.66 228.0 0.66 0.30 < 10 40.9 0.0 0.19 0.545 < 15

10/25/2007 25.42 3.86 3.98 329.0 0.09 1.15 < 10 30.0 0.0 0.22 7.4 2.2

11/7/2008 25.90 5.93 4.75 296.0 0.10 NM < 5 34.4 0.0 0.12 0.542 J < 15

12/8/2009 23.20 4.02 4.70 350.3 0.09 4.92 15 49 0.0 0.0615 J 0.556 < 25 2/15/2011 20.02 4.45 4.82 279.0 0.09 3.10 20 14.0 0.0 <0.02 0.71 64.0

3/31/2011 20.20 8.49 4.82 NM 0.09 16.00 20 NM NM NM NM NM

5/4/2012 RNA 5.02 RNA 251.4 RNA RNA < 0.34 0.0 0.2 0.036 < 0.78 < 0.272

4/16/2013 RNA 6.09 RNA 49.4 RNA RNA <0.19 0.0 0.2 0.035 <1.2 <0.486

10/23/2013 25.25 4.76 3.93 92.1 0.066 0.98 < 0.34 NM 0.2 0.012 4.4 J 452

2/26/2014 17.61 7.71 4.18 294 0.057 6.12 10 43.8 0.0 <0.050 <1.0 <0.25

10/14/2014 27.20 3.75 4.85 313.9 0.074 0.24 10 NM 0.0 <0.050 1.3 J <0.16 clear, no odor 3/18/2015 22.52 5.46 4.96 239 0.055 7.65 10 40.0 0.0 <0.050 4.2 <0.25 clear, no odor 9/29/2015 28.10 5.85 4.12 372.6 0.070 1.23 NM 30.0 0.0 <0.050 <1.0 <0.25 clear, no odor

MW-14

(Upgradient)

MW-17

(Upgradient)

MW-13

(Cross-gradient)

MW-12

(Cross-gradient)

MW-9

(Upgradient)

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina August 2005 to August 2022

Well Identification

Number (relative position to the source)

Date Sampled

Temperature (°C)

Dissolved Oxygen* (mg/L) pH

(SU)

ORP

(mV)

Specific Conductivity

(mS/cm)

Turbidity

(NTU)

Alkalinity (mg/L)

Carbon Dioxide (mg/L)

Ferrous Iron (mg/L)

Nitrogen/ Nitrate (mg/L)

Sulfate (mg/L)

Methane (μg/L) Note

8/16/2005 24.00 5.9 5.15 176 0.07 12.00 11.2 11.0 1.2 < 0.05 < 0 75.6 2/8/2006 21.69 0.4 4.92 196.2 0.09 -5.60 40.0 35.0 1.2 < 0.05 7.7 26.8

9/13/2006 23.95 0.17 4.97 184.8 0.06 2.20 < 10 70.0 1.2 < 0.10 3.7 < 26 3/21/2007 20.90 0.87 4.43 187.4 0.54 1.90 < 10 98.4 0.8 < 0.025 10.6 133.0

10/25/2007 24.50 1.08 4.96 198.0 0.09 1.46 < 10 52.0 0.3 < 0.05 25.7 156.0

11/7/2008 24.00 0.42 4.89 176.0 0.12 NM 7.93 J 14.3 0.9 < 0.025 32.1 267.0

12/8/2009 21.60 0.35 5.00 19.0 0.08 5.12 2 > 50 0.64 < 0.05 26.9 39.0 2/15/2011 15.35 0.91 5.05 37.0 0.09 8.90 40 13.0 0.6 <0.02 18.0 73.0

3/31/2011 19.50 8.35 5.18 NM 0.05 10.00 40 NM NM NM NM NM

5/4/2012 RNA 2.09 RNA 128.4 RNA RNA < 0.34 0.0 0.2 0.026 15.6 1.38 J

4/16/2013 RNA 0.62 RNA 3.0 RNA RNA <0.19 0.0 0.2 <0.005 33.2 1.28 J

10/23/2013 22.93 0.80 3.97 -7.6 0.049 1.52 3.0 NM 1.8 <0.008 2.6 J 602.0 clear, sulfur odor 2/26/2014 19.30 2.29 4.85 139 0.070 7.06 15.0 60 0.2 <0.050/ <0.050 33.2/ 40.8 9.7 B/ 10.2 B strong sulfur odor

10/15/2014 23.50 0.52 4.90 138.2 0.089 2.64 20.0 NM 0.0 0.17 21.0 2.2

3/17/2015 22.80 1.37 4.89 201.8 0.093 9.11 10.0 62 0.0 0.067 J 15.0 <0.25 clear, no odor 9/29/2015 26.00 2.53 4.95 -16.1 0.082 1.88 NM 65 0.0 0.17 8.6 34.6 clear, no odor 8/16/2005 23.50 1.1 5.33 108 0.296 22.40 45 10.5 0.9 < 0.05 143 173 2/8/2006 22.42 0.4 5.13 131.8 0.508 -2.30 40.0 40.0 1.2 < 0.05 J 167 326

9/13/2006 24.02 0.01 5.23 124.0 0.546 22.00 < 10 68.0 0.2 < 0.10 127 193 3/21/2007 21.90 1.22 4.62 209.0 0.21 1.60 < 10 74.0 0.8 < 0.025 89 2140

10/25/2007 24.53 1.07 5.90 81.0 0.42 0.37 < 10 40.0 0.3 < 0.05 218 74.4

11/7/2008 24.02 0.42 5.13 57.3 0.25 NM 16.3 11.3 0.3 < 0.025 89 126

12/8/2009 20.20 0.46 5.27 40.9 0.10 7.42 13 > 50 0.05 < 0.05 40.8 22.7 J clear, no odor 2/14/2011 21.35 0.56 5.40 70.0 0.12 8.00 40 14.0 0.0 <0.02 28.9 64.0

3/31/2011 19.60 8.21 5.39 NM 0.08 17.00 40 NM NM NM NM NM

5/4/2012 RNA 1.03 RNA 107.8 RNA RNA 11.4 0.0 0.2 0.017 33.9 1.73 J

4/16/2013 RNA 0.66 RNA -13.8 RNA RNA 6.7 0.0 0.2 0.007 J 33.1 <0.486

10/23/2013 23.62 0.64 4.75 20.4 0.174 11.60 6.7 0.0 0.6 <0.008 19.6 1220 clear, no odor 2/26/2014 18.71 2.10 4.67 193.0 0.100 7.16 20.0 80.0 0.0 <0.050 61.5 14.4 B clear no odor

10/14/2014 25.70 0.26 5.34 65.5 0.109 1.17 15.0 NM 0.0 <0.050 30.1 J 32.2 clear no odor 3/17/2015 26.91 0.00 5.20 98.0 0.090 3.89 25.0 92 0.0 <0.050 25.3 54.6 clear, no odor 9/29/2015 25.00 0.39 4.94 -41.7 0.097 1.32 NM 85 0.0 <0.050 19.7 158 clear, no odor

8/16/2005 24.70 5.39 534.00 NM 0.10 NM NM NM NM NM NM NM

2/8/2006 22.60 2.57 5.23 NM 0.06 >999 NM NM NM NM NM NM

9/13/2006 24.90 2.28 5.26 NM 0.062 >999 NM NM NM NM NM NM

3/21/2007 22.00 1.24 4.86 NM 0.051 107.00 NM NM NM NM NM NM

10/25/2007 25.50 3.6 5.03 NM 0.075 580.00 NM NM NM NM NM NM

11/7/2008 25.42 4.77 4.74 142.9 0.680 186.20 NM NM NM NM NM NM

12/8/2009 22.80 0.37 4.63 116 0.323 9.89 NM NM NM NM NM NM clear

2/15/2011 17.91 3.97 4.76 151 0.211 15.60 NM NM NM NM NM NM

10/23/2013 24.20 1.16 4.10 164.8 0.104 8.19 NM NM NM NM NM NM clear, no odor

2/26/2014 17.18 2.06 4.29 200 0.154 19.80 NM NM NM NM NM NM

10/14/2014 27.00 0.61 4.81 156.5 0.164 3.01 NM NM NM NM NM NM clear, no odor 3/18/2015 21.10 0.44 4.67 274.6 0.185 47.40 NM NM NM NM NM NM clear, no odor 9/29/2015 29.80 0.53 4.44 216.4 0.144 3.56 NM NM NM NM NM NM clear, no odor

Notes:

°C - degrees Celsius

* DO reported as percent NM - not measured mg/L – milligrams per liter mV – millivolt mS/cm – milliSiemens per centimeter μg/L - micrograms per liter ORP - oxidation-reduction potential NTU – nephelometric turbidity units MS/MSD – matrix spike/matrix spike duplicate RNA - report not available SU - standard unit

MW-18

(Cross-gradient)

MW-19

(Cross-gradient)

MW-20

(Cross-gradient)

Table 4 Groundwater Monitoring Results

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina July 2020, March 2021, and August 2022

Sa m pl e

N um be r

Sa m pl e

D at e

B en ze ne

T ol ue ne

E th yl be nz en e

X yl en es

(T ot al

M T

B E

N ap ht ha le ne

E th an ol

E th yl te rt -b ut yl e th er (E

T B

E

D iis op ro py l e th er

(D

IP

E

E th yl te rt -b ut an ol (E

T B

A )1 t-B ut an ol

(T B

A t-A m yl m et hy l e th er (T

A M

E

T er t-a m yl a lc oh ol (T

A A

T er t-b ut yl fo rm at e (T

B F)

5 1,000 700 10,000 40 25 10,000 47 150 -- 1,400 128 240 -- 2,100 -- -- -- -- -- -- -- -- -- -- -- -- --

Temporary Well* 7/24/2020 2,830 2,010 3,160 8,960 NS 88.2 J NS NS NS NS NS NS NS NS

MW-3 3/20/2021 <0.50 <0.50 <0.50 <1.5 5.4 <2.0 <100 <1.0 <0.50 <25 <10 0.32 J <10 <10 MW-5A 3/20/2021 <0.50 <0.50 <0.50 <1.5 <0.50 <2.0 <100 <1.0 <0.50 <25 <10 <1.0 <10 <10 MW-5R 3/20/2021 132 / 140 2.1 B / 2.3 JB 102 / 107 15.8 / 16.5 1.7 J / <1.3 9.2 J / 8.8 J <200 / <250 1.1 J / 1.3 J <1.0 / <1.3 <20 / <25 <20 / <25 <2.0 / <2.5 46.4 / 50.9 <20 / <25

MW-5R 8/9/2022 31.1 1.4 B 29.0 4.2 <0.50 U 2.8 J NS NS NS NS NS NS NS NS

MW-6A 3/20/2021 <0.50 <0.50 <0.50 <1.5 0.49 J <2.0 <100 <1.0 <0.50 <25 <10 <1.0 <10 <10 MW-6S 3/20/2021 <0.50 <0.50 <0.50 <1.5 <0.50 <2.0 <100 <1.0 <0.50 <25 <10 <1.0 <10 <10 MW-12 3/20/2021 <0.50 <0.50 <0.50 <1.5 <0.50 <2.0 <100 <1.0 <0.50 <25 <10 <1.0 <10 <10

Notes:

All units are in micrograms per liter (μg/L) USEPA Method SW-846 8260D was used for sample analysis.

Bolded Value – detected value Shaded – Exceeds SCDHEC RBSL Blue – Exceeds the site-specific target level SCDHEC – South Carolina Department of Health and Environmental Control B – Indicates analyte found in associated method blank (as noted in Data Validation Report, Appendix E).

J – Estimated value. Value detected between the detection limit (DL) and the limit of quantitation (LOQ).

< – Not detected above the associated value. Results have been reported to the Limit of Detection (LOD).

ND – Not detected NS – Not sampled 132/140 = Primary and duplicate sample results have been provided. The higher value was used in the evaluation of site data for this event.

* A direct push temporary well was installed and sampled after the premium gasoline tank's spill bucket failed a hydrostatic test.

1 – The chemical synonym presented in the lab reports is Tert-Butyl Alcohol.

SCDHEC RBSL

SSTL

Table 5 Historical Groundwater Monitoring Results

AOC V (TU542) - Shoppette UST and Distribution Lines Joint Base Charleston-Air

North Charleston, South Carolina August 2004 to August 2022

Sa m pl e

N um be r

Sa m pl e

D at e

Be nz en e

To lu en e

Et hy lb en ze ne

X yl en es

(T ot al

M

TB

E (m et hy l-t er t-bu ty e th er

N ap ht ha le ne

To ta l N ap ht ha le ne

1, 2-

D ic hl or oe th an e

1, 2-

D ib ro m oe th an e

Et ha no l

Et hy l t er t-bu ty l e th er

(E

TB

E)

D iis op ro py l e th er

(D

IP

E)

Et hy l t er t-bu ta no l (E

TB

A t- Bu ta no l (

TB

A t- A m yl m et hy l e

(T

A M

E)

Te rt

-a m yl a lc oh ol (T

A A

Te rt

-b ut yl fo rm at e (T

BF

Be nz o( a) an th ra ce ne

Be nz o( b) flu or an th en e

Be nz o( k) flu or an th en e

C hr ys en e

D ib en zo

(a ,h

)a nt hr ce ne

To ta l P A

H

5 1,000 700 10,000 40 25 25 5 0.05

(MCL) 10000 47 150 -- 1400 128 240 -- 10 10 10 10 10 25

5/4/2012 <0.099 <0.127 <0.119 <0.384 <0.060 <0.065 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

4/16/2013 3.4 34 5.6 30 <0.078 <0.176 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

10/23/2013 <0.111 <0.122 <0.109 <0.179 <0.078 <0.078 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

2/25/2014 <0.50 <0.50 <0.50 <1.0 <0.50 <2.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

10/14/2014 <0.50 <0.50 <0.50 <1.0 <0.50 <2.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

3/17/2015 <0.50 <0.50 <0.50 <1.0 <0.50 <2.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

9/29/2015 <0.50 <0.50 <0.50 <0.50 <0.50 <2.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

3/10/2016 <0.50 <0.50 <0.50 <1.0 <0.50 <2.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

2/24/2017 <0.50 <0.50 <0.50 <1.5 <0.50 <2.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

3/23/2005 < 1 < 1 < 1 2.4 31.5 < 5 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

3/23/2005 <1 <1 <1 2.0 29.6 < 5 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

8/16/2005 <1 <1 <1 < 3 71.2 NA NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

8/16/2005 <1 <1 <1 < 3 71.9 NA NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

2/8/2006 < 1 < 1 < 1 < 2 72.7 < 5 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

9/13/2006 < 1 < 1 < 1 < 3 77.1 < 5 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

3/22/2007 < 0.33 < 0.42 < 0.42 < 0.45 74.8 < 0.65 NS NS NS NS NS NS NS NS NS NS…