B.08 GFI JB CHS PBR Draft Final LF003 (SWMU 3) Monitoring & LUC Inspection Work Plan.pdf

Attachment A. SWMU 3 (LF003) MONITORING AND LUC INSPECTION

WORK PLAN

Uniform Federal Policy

Quality Assurance Project Plan

Draft Final December 2020

Version 00

Basewide Groundwater, Surface Water, and Land Use Control Monitoring

Joint Base Charleston Weapons, Charleston, South Carolina

Contract FA8903-15-C-0016

Prepared for:

AFCEC/CZRE

US Air Force Civil Engineer Center 772nd ESS/PKS

2261 Hughes Avenue, Suite 155 JBSA Lackland, TX 78236-9853

Prepared by:

AECOM

4016 Salt Pointe Parkway

North Charleston, South Carolina 29405

With Teaming Partners:

UFP-QAPP Attachment A: SWMU 3 (LF003) Monitoring and LUC Inspection Work Plan Basewide Groundwater, Surface Water, Land Use Control Monitoring

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 1 BWJ140078

1.0 SITE INFORMATION

Site Description Site Name: Old Northside Landfill (Solid Waste Management Unit [SWMU] 3/LF003) Site Stage: Long-Term Management (LTM) Location Joint Base Charleston (JBC) Weapons is located 10 miles north of Charleston, South Carolina, approximately 16 miles inland from the Atlantic Ocean. The facility is situated in two counties, Berkeley and Charleston, and occupies 16,868 acres. SWMU 3 occupies approximately 10 acres in the southwestern portion of the Polaris Missile Facility Atlantic Fleet (POMFLANT) area and is adjacent to Foster Creek (Figure 1).

Historical Use The landfill, which operated from 1962 to 1978, received solid waste, oily waste, and solvents from the POMFLANT area, and large quantities of solid waste including construction and demolition debris, furniture, waste paving material, railroad ties, steel rails, and wooden crates.

Liquid wastes included toluene, methyl ethyl ketone, acetone, and mineral spirit solvents; disposal rates were estimated to be 500 to 1,500 gallons annually.

SWMU 3 is not currently used for any purpose (recreational, industrial, commercial, residential, etc.) with the exception of seasonal hunting, and current land use at the site is not expected to change in the near future. The land surrounding SWMU 3 is undeveloped.

Previous Investigations From 1991 to 1993, the United States Geological Survey (USGS) performed an assessment on Foster Creek, which included the area around SWMU 3 (USGS, 1993). The purpose of the study was to assess potential release of contaminants to Foster Creek, which is a secondary source of drinking water for the Charleston area. Samples were collected from stream sediment and surface water. The results were summarized as follows:

“A number of naturally occurring inorganic compounds were detected throughout Foster Creek and its tributaries during low-flow surface water sampling. Of the inorganic compounds detected, three exceeded the USEPA [Secondary Maximum Contaminant Levels] (SMCLs): aluminum (650 micrograms per liter [µg/L] maximum), iron (2,740 µg/L maximum), and manganese (85.6 µg/L maximum).

These metals typically are found in surface water and ground water in the study region, and normally exceed the USEPA SMCL’s in nearly all coastal freshwater stations sampled by SCDHEC.”

Between 1993 and 1995, Phase I and II Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) activities were conducted at SWMU 3 (ABB-ES, 1996). In 1993, a Phase I RFI was completed by ABB-ES at SWMU 3. The primary purpose of the investigation was to determine if contaminants from the site had adversely affected the water quality of Foster Creek.

A Human Health Risk Assessment (HHRA) and Ecological Risk Assessment (ERA) were conducted for constituents detected in site media collected from SWMU 3 during the RFI.

The Phase I RFI activities at SWMU 3 included:

• Ten surface water/sediment samples from drainage areas around the former landfill;

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Contract FA8903-15-C-0016 2 BWJ140078

• One surface water/sediment sample from Foster Creek, downstream from the former landfill;

• Three subsurface soil samples from monitoring well borings; and

• Groundwater samples collected from nine monitoring wells located around the perimeter of the former landfill (NSW-3-1 through NWS-3-9).

The Phase II RFI activities at SWMU 3 included:

• Nine surface soil and five subsurface soil samples around the perimeter of the former landfill; and

• Groundwater samples from eight monitoring wells (NWS-3-1, NWS-3-2, NWS-3-3, NWS-3-5, NWS-3-7, NWS-3-8, NWS-3-9, and NWS-3-10). Wells NWS-3-4 and NWS-3-6 could not be located.

A Baseline Risk Assessment (BRA) for Corrective Action Management Plan Group A (which included SWMUs 3, 4, 5, and 6) was prepared in 1996 (ABB-ES, 1996) based on information collected during the RFI and documented in the Supplemental RFI Workplan (ABB-ES, 1995).

Additional samples were collected, and a final BRA was developed in 1999 based on information collected during the supplemental RFI (ABB-ES, 1999). Qualitative and quantitative evaluations of risks to human health and the environment were completed for exposures in surface soil, subsurface soil, sediment, surface water, and groundwater. Human health and ecological risk assessments for SWMU 3 were completed.

A conceptual site model (CSM) was developed using data from the RFI. The primary source of contaminants at SWMU 3 is waste disposed within the landfill. The primary release mechanism is direct deposition to surface soil. Infiltration/percolation was also identified as a potential primary release mechanism because liquid source materials were disposed in the landfill. Environmental media potentially impacted by release of source contamination included surface soil, subsurface soil, and groundwater beneath the unit. Potential impacts to the nearby creek and associated drainage areas may have occurred due to erosion of primary source materials or surface runoff.

However, this pathway was eliminated with the placement of the soil cover over the landfill material. Leaching from soils to groundwater with subsequent migration to discharge points along seeps at Foster Creek and associated drainages were also identified as potential contaminant migration pathways.

Corrective action was implemented at SWMU 3 in December 1994 and January 1995. Activities included removing the remaining construction debris, clearing vegetation, and using fill dirt to raise the elevation of the lower areas of the landfill. A one-foot thick clay cap was placed on the landfill surface after activities were complete (ABB-ES, 1995).

In 1999, a Groundwater Monitoring Work Plan for SWMU 3 was developed to institute a five-year groundwater monitoring plan for the site (Tetra Tech, 1999). In July 1999, periodic groundwater monitoring was initiated at SWMU 3 in accordance with the five-year monitoring program. The first year of periodic monitoring was conducted quarterly and was reduced to annually during the second year. Landfill inspections were conducted during groundwater monitoring activities (ABB-

ES, 1995).

Following completion of the five-year groundwater monitoring period, a Five-Year Review Report for Groundwater Monitoring was prepared documenting trends in groundwater concentrations (RCS, 2007). Based on the results from the monitoring program, arsenic and manganese were the only inorganic constituents consistently detected above Maximum Contaminant Levels (MCLs) and facility background. Arsenic concentrations were centered on wells located near the middle of the landfill (NWS-3-1 and NWS-3-3). Elevated manganese concentrations are in wells

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 3 BWJ140078 located to the west of the landfill and do not appear to be related to contamination from the landfill.

Recommendations were made to reduce the number of wells sampled during long-term monitoring from ten to six and to continue annual groundwater analyses.

The CSM presented in the 1996 RFI was updated as part of the Five-Year Review for Groundwater Monitoring (RCS, 2007). It was concluded that results from the sediment, surface water and soil investigations support the assumptions of the CSM. Within the landfill, contaminated media were detected in only localized areas and no risk to human health was identified (ABB-ES, 1996). Given the age of the landfill, it is not likely that the primary release mechanisms remain as potential concerns. The groundwater monitoring data collected over the monitoring history of the unit further support that there has not been a sustained release of contaminants to groundwater.

Periodic groundwater monitoring was continued at six wells for volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and metals through 2011, the tenth year of periodic groundwater monitoring. Throughout monitoring, groundwater analytical results were compared to regulatory standards, facility background values, and risk-based screening levels. Variations in groundwater concentrations over time have been evaluated and elevated metals concentrations continue to be present in some monitoring wells. In 2012, arsenic and manganese were observed at concentrations exceeding their respective MCLs and/or established background levels (TEC-BSC, 2014). It was determined that arsenic in groundwater was not fully delineated along the west/southwestern side of the landfill.

Based on the HHRA and subsequent periodic groundwater monitoring, arsenic and manganese were determined to be chemicals of potential concern (COPCs) in groundwater at SWMU 3.

COPCs (arsenic and manganese) and media cleanup standards (MCSs) were presented in the Uniform Federal Policy – Quality Assurance Project Plan (UFP-QAPP) and CMS/ Interim Measure (IM) Work Plan (AECOM, 2016). The MCS for each constituent of concern at the site to allow for unlimited use/unrestricted exposure (UU/UE) are presented below.

Constituent of Concern

Media Cleanup Standard (µg/L) Rationale for MCS

Arsenic 10 MCL Manganese 430 RSL

Notes: MCL – maximum contaminant level; RSL – regional screening level.

Plume delineation activities are documented in the 2016 Annual Report (AECOM, 2017) for SWMU 3. Investigation activities were completed in November 2016 and March 2017. Per the approved CMS/IM Work Plan, wells NWS-3-3R and NWS-3-1RR were abandoned on November 15, 2016. Three monitoring wells (NWS-3-11, NWS-3-12, and NWS-3-13 were installed at SWMU 3 to delineate the COPCs in groundwater downgradient of the landfill, and one well (NWS-3-14) was installed upgradient of the landfill.

IM activities were completed in March 2017. The objective of the IM was to evaluate the applicability of PeroxyChem EHC Metals (EHC-M®) as an amendment to remediate low levels of metals along the downgradient side of the landfill where arsenic and manganese concentrations have remained above the MCSs in wells NWS-3-8 and NWS-3-9. Post-injection surface and groundwater monitoring was performed in 2017 (June, September, and December) and 2018 (March). A detailed assessment of the IM injections can be found in the IM Completion Report (AECOM, 2018). Contaminant concentrations fluctuated following injections with initial increases of arsenic and manganese in many wells. Arsenic and manganese concentrations have decreased to below MCSs at select wells, however a consistent response has not been observed at all wells located downgradient of the landfill. Contaminants present in groundwater along the

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 4 BWJ140078 downgradient side of the landfill were not present in surface water at levels above their respective MCSs. Surface water samples were collected during each of the post-injection monitoring events.

All surface water analytical results for arsenic and manganese were below their respective MCSs.

Land Use Controls Land use controls (LUCs) have been implemented at the site to restrict human contact with solid waste material contained within the landfill, restrict soil disturbance activities that may expose waste material, and prohibit residential development of the site. These LUCs have been reviewed and approved by South Carolina Department of Health and Environmental Control (SCDHEC) and will be maintained during remedial action. Additional LUCs include providing signage identifying the landfill; prohibiting groundwater use for potable purposes; and adding administrative controls as part of a facility wide notification system that alerts individuals who want to perform activities that may disturb the ground in the vicinity of SWMU 3 that LUCs are in place.

LUCs at JBC Weapons are tracked through inclusion of the site in the JBC Weapons Installation Development Plan. The Base Remedial Project Manager works with the 628 Civil Engineer Squadron Base Community Planner (Base Community Planner) to confirm that LUCs are implemented and enforced at applicable sites. Annual LUC inspections will be performed to confirm compliance with the LUCs using the SWMU 3 LUC Monitoring Checklist (Attachment 1)

2.0 SUMMARY OF PROJECT TASKS

Groundwater monitoring, surface water monitoring, LUC inspections, contingency injections, and annual reporting are included in the remedy for SWMU 3 in accordance with the Statement of Basis. Groundwater monitoring will be conducted for metals (total and dissolved), VOCs, SVOCs, and pesticides at nine monitoring wells. Surface water sampling will be conducted for arsenic and manganese at three surface water points considered to be points of compliance.

The LUC monitoring program is being implemented in accordance with Appendix D of the RCRA Permit. Annual inspections will be conducted to ensure that the LUCs remain in effect at the site.

The area to be covered by the LUCs is presented on Figure 1. The LUCs ensure that proper planning, permissions, and safety considerations will be implemented prior to future construction activities or change in land use on the site. In support of this, the following field activities/schedule will be conducted:

Task Frequency Anticipated Month

Information Reported to Regulators

Documentation of LUC boundaries in the Installation Development Plan and review of proposed activities within the LUC boundaries through the installation dig permit process.

Ongoing Ongoing Report change in land use, if any.

Groundwater Monitoring Annual Fourth Quarter Within 90 days of sampling Compliance Point (Surface Water) Monitoring Annual Fourth Quarter Within 90 days of sampling

LUC Inspection Annual Fourth Quarter Within 90 days of inspection

2.1 Groundwater Monitoring

Groundwater monitoring will be conducted annually during the fourth quarter of the year. Prior to each sampling event, groundwater levels will be collected from each of the nine wells. Water level measurements will be made to the nearest 0.01-foot using an electric water level meter.

Groundwater samples will be collected using low-flow sampling techniques. Measurement and

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 5 BWJ140078 sampling procedures will be conducted in accordance with the Standard Operating Procedures (SOPs) (Worksheet #21) and as described in Worksheet #14 of the UFP-QAPP.

A field duplicate sample and matrix spike/matrix spike duplicate (MS/MSD) will be collected during each sampling event. Table 1 summarizes the analytical methods by well.

2.2 Compliance Point (Surface Water) Monitoring

Surface water monitoring will be conducted annually during the fourth quarter of the year. These locations will be used as compliance points for arsenic and manganese in groundwater. Sampling procedures will be conducted in accordance with the SOPs (Worksheet #21) and as described in Worksheet #14 of the UFP-QAPP. Table 1 summarizes the analytical methods for each point.

Should analytical results at any of the surface water compliance points exceed the MCL during the annual sampling event, the compliance points will be resampled during the first quarter of the following year for both total and dissolved arsenic and manganese to confirm the result. If the confirmation sampling is also above the MCL, the compliance points will be resampled during the second quarter of the year. If the results of the initial sampling, confirmation sampling, and semi-annual sampling all exceed the MCL, implementation of the contingency remedy of in situ chemical reduction will be discussed with SCDHEC. Based on the evaluation of analytical data and input from SCDHEC an implementation plan will be developed and submitted to SCDHEC for approval prior to implementation (AECOM, 2019).

2.3 Land Use Control Inspections

LUC inspections will be conducted annually. The inspections will consist of a site walk to observe site conditions, changes and repairs to existing soil cover, and any changes in site use that are inconsistent with LUC requirements. The LUC inspections will be documented using the LUC checklist (Attachment 1).

2.4 Annual Reporting

The groundwater monitoring results and completed LUC checklist will be submitted annually within 90 days of the monitoring activities. The annual report will document the groundwater and surface water monitoring activities, the analytical results, and LUC inspections along with any deficiencies and measures taken to correct deficiencies.

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Figure 1. SWMU 3 (LF003) Site Map

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 7 BWJ140078

REFERENCES

ABB-ES, 1995. Technical Memorandum and Supplemental Resource Conservation and Recovery Act Facility Investigation Workplan, Camp Group A, Naval Weapons Station, Charleston, South Carolina. April.

ABB-ES, 1996. Final Draft Baseline Risk Assessment for Corrective Action Management Plan Group A, Naval Weapons Station, Charleston South Carolina, prepared for Department of the Navy, Southern Division, Naval Facilities Engineering Command, Contract No.

N62467-89-D-0317/032, June.

ABB-ES, 1999. Final Baseline Risk Assessment for Corrective Action Management Plan Group A, Naval Weapons Station, Charleston South Carolina, prepared for Department of the Navy, Southern Division, Naval Facilities Engineering Command, Contract No. N62467- 89-D-0317/032, June.

AECOM, 2016. Uniform Federal Policy – Quality Assurance Project Plan and Corrective Measures Study/Interim Measures Work Plan, SWMU 3, Joint Base Charleston Weapons.

September.

AECOM, 2017. Draft Interim Measures Report, SWMU 3, Joint Base Charleston Weapons, Charleston, SC. July.

AECOM, 2018. Interim Measures Completion Report, SWMU 3, Joint Base Charleston Weapons, Charleston, SC. November.

AECOM, 2019. Final Corrective Measures Study, Solid Waste Management Unit 3 (LF003), Joint Base Charleston Weapons, South Carolina. October.

RCS Corporation, 2007. Year 5 Long Term Monitoring Report, SWMU 3, Naval Weapons Station.

Charleston, South Carolina. November

South Carolina Department of Health and Environmental Control. Bureau of Land and Waste Management. Revised, 2015. Resource Conservation and Recovery Act (RCRA) Part B permit number SC8 170 022 620, effective 22 September 2011 through 22 September 2021.

Tetra Tech, 1999. Groundwater Monitoring Work Plan for SWMU 3 – Old North Side Landfill, Naval Weapons Station Charleston, Charleston, SC. July.

TEC-BSC Joint Venture, 2014. Final 2012 Annual Monitoring Report, SWMU 3 – Old North Side Landfill, Naval Weapons Station Charleston, Charleston, SC. March.

USGS, 1993. Water Quality, Bed-Sediment Quality, and Simulation of Potential Contaminant Transport in Foster Creek, Berkeley County, South Carolina, 1991-1993

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 BWJ140078

Table

Table 1 Groundwater and Surface Water Monitoring Matrix

SWMU 3

Location Sample ID Matrix Depth Metals - As, Mn

(total) Metals (total)

Metals (dissolved)

Mercury (total)

Mercury (dissolved)

VOCs SVOCs Pesticides

6020B 6020B 6020B 7470A 7470A 8260B 8270D 8081B Annual Monitoring

NWS-3-4A NWS-3-4A-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-5R NWS-3-5R-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-8 NWS-3-8-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-9 NWS-3-9-YYYYMMDD Groundwater Shallow X X X X X X X

NWS-3-10 NWS-3-10-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-11 NWS-3-11-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-12 NWS-3-12-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-13 NWS-3-13-YYYYMMDD Groundwater Shallow X X X X X X X NWS-3-14 NWS-3-14-YYYYMMDD Groundwater Shallow X X X X X X X

SW-01 SW-01-YYYYMMDD Surface Water Surface X SW-02 SW-02-YYYYMMDD Surface Water Surface X SW-03 SW-03-YYYYMMDD Surface Water Surface X

Notes:

As - arsenic IM - Interim Measures Mn - manganese SWMU - Solid Waste Management Unit SVOC - semi-volatile organic compound VOC - volatile organic compound YYYYMMDD - year, month, day

Joint Base Charleston Weapons, South Carolina

Contract FA8903-15-C-0016 BWJ140078

Attachment 1: LUC Checklist