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HomeMy WebLinkAboutWI0800138_Correspondence_20081015DRAFT INTERIM REMEDIAL ACTION COMPLETION REPORT OPERABLE UNIT NO. 16 - SITE 93 MARINE CORPS BASE CAMP LEJEUNE, NORTH CAROLINA Prepared for: DEPARTMENT OF THE NAVY Naval Facilities Engineering Command, Mid -Atlantic 6506 Hampton Boulevard Norfolk Virginia 23508-1273 Contract No. N62470-02-D-3260 TO 0063 Prepared by: Shaw Environmental, Inc. Main Street, Norfolk, Virginia Ronald Kenyon Technical Manager Joseph W. Colella, P.E. Project Manager James A. Dunn, Jr., P.E. Program Manager Project No. 120348 October 2008 TABLE OF CONTENTS 1.0 INTRODUCTION..........................................................................................................1-1 1.1 OBJECTIVE ................................................................................................................................................ 1-1 1.2 SITEBACKGROUND...............................................................................................................................1-1 1.3 SUMMARY OF PREVIOUS SITE INVESTIGATIONS........................................................................... 1-2 1.3.1 UST Investigation(1995)................................................................................................................... 1-2 1.3.2 Remedial Investigation(1998)........................................................................................................... 1-2 1.3.3 Natural Attenuation Evaluation(2001)....-....................................................................................._. 1-3 1.3.4 Additional Plume Characterization (2002)........................................................................................ 1-3 1.3.5 Supplemental Site Investigation(2005)........... -................................................................................ 1-3 1.3.6 Feasibility Study(2005).................................... ...... .-......... ............................................................... 1-3 1.3.7 Proposed Remedial Action Plan(2006)....... -.................................................................................... 1-4 1.4 PRIOR REMOVAL OR REMEDIATION ACTIVITIES........................................................................... 1-5 2.0 OPERABLE UNIT BACKGROUND..........................................................................2-1 2.1 RECORD OF DECISION (ROD) REQUIREMENTS .... ........................................................................... 2-1 2.1.1 Description of the Selected Remedy.................................................................................................. 2-1 2.1.2 Selected Cleanup Goals..................................................................................................................... 2-2 2.2 REMEDIAL DESIGN SUMMARY........................................................................................................... 2-3 2.3 MATERIALS COMPATIBILITY..............................................................................................................2-6 2.4 MASS OF KMN04...................................................................................................................................... 2-6 2.5 INJECTION SEQUENCE, INJECTION RATES, AND HYDRAULIC CONTROL ..... ....... ...... ___ ..... - 2-7 2.6 CONCENTRATION OF KMN04 INJECTION SOLUTION..................................................................... 2-7 2.7 SOIL OXYGEN DEMAND........................................................................................................................2-7 2.8 SITE GEOLOGY........................................................................................................................................ 2-8 2.9 SITE HYDROGEOLOGY..........................................................................................................................2-9 3.0 REMEDIAL ACTION IMPLEMENTATION...........................................................3-1 3.1 SITE PREPARATION AND UTILITY CLEARANCE......................................_..................................... 3-1 3.2 INJECTION POINTS LAYOUT................................................................................................................ 3-2 3.3 INJECTION POINT INSTALLATION AND DEVELOPMENT.............................................................. 3-2 3.4 PRE -INJECTION GROUNDWATER SAMPLING................................................................................... 3-3 3.5 PERMANGANATE INJECTION SYSTEM MOBILIZATION AND SETUP ......................................... 3-4 3.6 SECURITY................................................................................................................................................. 3-5 4.0 PHASE 1 INJECTION OCTOBER, 2006 THROUGH FEBRUARY, 2007 ............ 4-1 4.1 PERMANGANATE INJECTION SYSTEM OPERATION.......................................................................4-1 4.1.1 Permanganate Solution Mixing..........................................................................................................4-1 4.1.2 Pertanganate Solution Injection.......................................................................................................4-1 4.1.3 Operational Monitoring..................................................................................................................... 4-3 4.1.4 Operational Problems and Adjustments ............................................ ........ ......................................... 4-4 4.2 POST -INJECTION REVIEW .......................... ......................... .......................................... ........................ 4-5 4.3 SITE 93 PUMP TEST ................................................................................................................................. 4-6 5.0 PHASE 2 INJECTION JUNE, 2007 THROUGH DECEMBER, 2007 ....................5-1 5.1 ADDITIONAL SITE EVALUATION_, ....................... .......... ....... ...................... ................. 5-1 5.2 PHASE 2 OPERATIONS............................................................................................................................ 5-1 5.3 DECONTAMINATION and DEMOBILIZATION.................................................................................... 5-2 5.3.1 Heavy Equipment............................................................................................................................... 5-2 5.3.2 Sampling Equipment.......................................................................................................................... 5-3 5.3.3 KMnO4 Injection System................................................................................................................... 5-3 5.4 POST -INJECTION MONITORING... .. . ......................................... __ ..................................................... 5-4 5.5 SITE RESTORATION................................................................................................................................ 5-4 6.0 PROJECT MONITORING..........................................................................................6-1 6.1 GROUNDWATER MONITORING...........................................................................................................6-1 6.1.1 Ground Water Baseline Analysis....................................................................................................... 6-1 6.1.2 Phase 2 Analysis................................................................................................................................ 6-2 6.2 SURFACE WATER MONITORING......................................................................................................... 6-4 Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 - Site 93 1 October 2008 6.3 ISCO PERFORMANCE CRITERIA.......................................................................................................... 6-5 6.4 HEALTH AND SAFETY........................................................................................................................... 6-5 6.5 COMPARISON TO CLEANUP GOALS., ................................................................................................. 6-5 6.6 LAND USE CONTROIS........................................................................................................................... 6-6 6.7 LESSONS LEARNED.............................................................................................................................-6-6 7.0 SCHEDULE AND COSTS............................................................................................7-1 8.0 REFERENCES...............................................................................................................8-1 LIST OF TABLES 3.1 Chronology of Events 6.1 Groundwater Analytical Data Summary 6.2A COC Data — Phase One 6.213 COC Data — Phase Two 6.3 MW-06 Groundwater Analytical Data —TAL Metals 6.4 MW-08 Groundwater Analytical Data — TAL Metals 6.5 MW-17 Groundwater Analytical Data — TAL Metals 6.6 MW-13Groundwater Analytical Data —TAL Metals 6.7 MW-05 Groundwater Analytical Data — TAL Metals 6.8 MW-12 Groundwater Analytical Data — TAL Metals 6.9 MW-14 Groundwater Analytical Data — TAL Metals 6.10 MW-15 Groundwater Analytical Data — TAL Metals 6.11 MW-16 Groundwater Analytical Data — TAL Metals 6.12 MW-09 Groundwater Analytical Data — TAL Metals 6.13 Groundwater Analytical Data —Natural Attenuation Indicator Parameters LIST OF FIGURES 1-1 Site Vicinity Map 1-2 Site Location Map 1-3 Contaminant Plume Limits 2-1 2004 Plume Characterization 2-2 Groundwater Contour Map (2005) 3-1 Permanganate Treatment Area Layout 3-2 Injection Point Construction Diagram 3-3 System Process Flow Diagram 6-1 Treatment Area Ground Water Quality 6-2 MW-06 COC Concentrations over Time 6-3 MW-08 COC Concentrations over Time 6-4 MW-17 COC Concentrations over Time Interim Remedial Action Completion Report Operable Unit No. 16—Site 93 it Project 120348 October 2008 6-5 MW-13 COC Concentrations over Time 7-1 Project Schedule APPENDICES Appendix A — Cost and Performance Summary Appendix B — Analytical Data Reports Appendix C — Pump Test Data and Evaluation Appendix D — Site Photographs Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 iii October 2008 List of Acronyms ANSI American National Standards Institute BCT BRAC Cleanup Team bgs Below Ground Surface BHHRA Baseline Human Health Risk Assessment BRAC Base Realignment and Closure CMI Corrective Measure hnplementation CMS Corrective Measures Study COC Chemical(s) of Concern COPC Chemical of Potential Concern COPEC Chemical of Potential Ecological Concern DCE Dichloroethene EPA U.S. Environmental Protection Agency FADL Field Activity Daily Log gpm Gallons per Minute GSWSA Grand Strand Water and Sewer Authority H&S Health and Safety Hp Horsepower ICM Interim Corrective Measure ISCO In -Situ Chemical Oxidation IR Installation Restoration IT IT Corporation LUC Land Use Control MBAFB Myrtle Beach Air Force Base MCB Marine Corps Base MCL Maximum Contaminant Level MDC Maximum Detected Concentration mg/kg Milligrams per Kilogram mg/L Milligrams per Liter MPE Multiphase Extraction msl Mean Sea Level NAIP Natural Attenuation Indicator Parameters NSF National Sanitation Foundation ORP Oxidation -Reduction Potential PCA 1,1,2,2 TetraChloroethane Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 iv October 2008 PCE Tetrachloroethylene List of Acronyms (Continued) POL Petroleum Oil and Lubricants PPE Personal Protective Equipment ppm Parts per Million psi Pounds per Square Inch PVC Polyvinyl Chloride QAPP Quality Assurance Project Plan QA/QC Quality Assurance/Quality Control RCRA Resource Conservation and Recovery Act RDW Remediation Derived Waste RFI RCRA Facility Investigation SLERA Screening Level Ecological Risk Assessment SNIP Site Management Plan SOW Scope of Work SSHP Site -Specific Safety and Health Plan SVOC Semivolatile Organic Compound SWMU Solid Waste Management Unit TAL Target Analyte List TCE Trichloroethylene TERC Total Environmental Restoration Contract µg/kg Micrograms per Kilogram µg/L Micrograms per Liter UIC Underground Injection Control USACE U.S. Army Corps of Engineers USAF U.S. Air Force VC Vinyl Chloride VOC Volatile Organic Compound Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 v October 2008 1.0 INTRODUCTION This Interim Remedial Action Completion Report (IRACR) documents the remedies for Operable Unit (OU) 16, Site 93 at Marine Corp Base, Camp Lejeune have been implemented and maintained in accordance with the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA) and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). This IRACR includes the results of the Remedial Investigation (RI), Feasibility Study (FS), Proposed Remedial Action Plan (PRAP), Record of Decision (ROD), and Remedial Basis of Design (RBD) and proposes implementation of Long Term Monitoring (LTM) and Land Use Controls (LUC) at OU 16. This IRACR has been prepared by Shaw Environmental, Inc (Shaw) under Department of the Navy's Remedial Action Contract administered by the Naval Facilities Engineering Command, Atlantic Division (LANTDIV) and follows the Department of Defense (DoD) / U.S. Environmental Protection Agency (EPA) Joint Guidance on Streamlined Site Closeout (DoD/EPA, January 2006). This IRACR was prepared under Contract Number N62470-02-D- 3260, Task Order 063. 1.1 OBJECTIVE The objective of this IRACR is to provide a description of the activities performed to implement the selected remedy for groundwater remediation at OU No. 16 Site - 93. The Remedial Action entails in -situ chemical oxidation (ISCO) using potassium permanganate (chemical formula: KMn04). 1.2 SITE BACKGROUND Site 93 is located within the Camp Geiger portion of Camp Lejeune (Figure I-1) near Building TC-942 at the intersection of Ninth and E Streets, as shown in Figure I-2. The buildings in this portion of Camp Geiger were constructed during the Korean War and currently function as classrooms, barracks, and supply rooms for the Marine Infantry School. Site 93 is relatively flat with portions covered by asphalt, gravel, and grass. The eastern portion of the site is wooded and slopes gently towards Edwards Creek. Ground surface elevations in the vicinity of Site 93 are approximately 5 to 20 feet above msl. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 1-1 October 2008 During an underground storage tank (UST) removal project in December 1993, dissolved phase chlorinated solvents were discovered off the southwest corner of Building TC-942. In 1995, a UST investigation was performed where saturated zone samples revealed groundwater impacted with chlorinated solvents, primarily tetrachloroethylene (PCE), trichloroethylene (TCE) and cis - and trans-1,2-dichloroethene (DCE) (Wright 1995). Groundwater contamination was found to be as shallow as 3 feet below ground surface (bgs). A baseline human health risk assessment (Baker, 1998) identified the chlorinated solvents tetrachloroethylene and cis-1,2-DCE, as well as, arsenic and manganese as chemicals of concern (COC) in groundwater warranting evaluation of remedial options. Figure 1-3 illustrates the extent of contamination at this site. This remedial action was performed at Site 93 to implement groundwater remediation to address contamination at the site per the results of the Feasibility Study (FS) (CH2MHill, 2005) and the approved PRAP. The Feasibility Study recommended ISCO using potassium permanganate. The Basis of Design (Shaw 2006) was submitted to the Camp Lejeune Partnering Team and approved by the NAVFAC, the U.S. Environmental Protection Agency (EPA) Region 4 and the North Carolina Department of Environment and Natural Resources (NCDENR) in October 2006. 1.3 SUMMARY OF PREVIOUS SITE INVESTIGATIONS 1.3.1 UST Investigation (1995) After the removal of the former waste oil UST at Building TC-942, an investigation was performed to determine the extent of the petroleum related contamination in the soil and groundwater associated with the UST. The investigation included the installation of monitoring wells in the vicinity of the former UST excavation and the collection of soil and groundwater samples. Chlorinated volatile organic compounds (cVOCs) were detected in soil and groundwater samples above North Carolina Groundwater Quality Standards (NCGWQS). 1.3.2 Remedial Investigation (1998) In 1996 and 1997, the RI was conducted to delineate the nature and extent of the contamination. Field activities included the installation of permanent and temporary monitoring wells and the collection of soil and groundwater samples analyzed for chlorinated volatile organic compounds (cVOCs). Soil analytical results indicated that the soil had not been significantly impacted by the site -related activities. Groundwater analytical results identified cVOC contamination (primarily trichloroethene [TCE]) concentrated in the surfrcial aquifer (less than 15 feet below ground surface [bgs]) within the immediate area of the former UST. A groundwater plume was identified as generally extending from Building G-920 east to "E" Street, between Ninth and Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 - Site 93 1-2 October 2008 Tenth Streets. Groundwater analytical data also suggested contaminant discharge to Edwards Creek was occurring. 1.3.3 Natural Attenuation Evaluation (2001) In 2001, a preliminary Natural Attenuation Evaluation (NAE) was conducted to determine whether natural site conditions would encourage the natural attenuation process to degrade TCE. The results indicated limited natural attenuation of chlorinated solvents was occurring. The reductive dechlorination process appeared to be stalling, indicating that the reduced state of the aquifer was not enough to encourage optimal dechlorination. 1.3.4 Additional Plume Characterization (2002) Additional plume characterization / delineation activities were conducted including the installation of permanent monitoring wells and the collection of groundwater samples. The analytical results identified several "hot spot' areas. The primary plume appeared related to the former UST area, with smaller "hot spot' areas downgradient. The results indicated horizontal migration of the groundwater contamination had been minimal since 1995; however, vertical migration was observed. During the RI (1998), cVOC concentrations above NCGWQS were generally limited to a depth of 15 feet bgs; while in 2002, elevated levels of cVOCs were identified up to a depth of approximately 30 feet bgs, with impacts concentrated at 15 to 19 feet bgs. 1.3.5 Supplemental Site Investigation (2005) A supplemental site investigation was performed to detemnine the current conditions of groundwater contamination in the surficial aquifer and collect additional data to support the selection of a remediation alternative. Groundwater samples were collected from boring locations at three depths, and analyzed for VOCs, iron, and manganese, chloride, nitrate, nitrite, sulfate, methane, ethane, ethene, sulfide, total dissolved solids and total suspended solids. Once the groundwater screening results were analyzed, additional permanent monitoring wells were installed to complete the horizontal and vertical delineation of the shallow groundwater contamination. The results of this investigation formed the basis of the nature and extent of contamination for the FS. 1.3.6 Feasibility Study (2005) The FS report (CH2MHill, 2005) summarized the previous investigations and assessments which were performed at Site 93 and evaluated several alternatives to remediate the site. The overall conclusion of the investigations was that chlorinated solvents are present in groundwater at Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 —Site 93 1-3 October 2008 concentrations above the 2L standard, with the majority of the impact occurring in the surficial aquifer (516feet). The long term monitoring of the site, 1999 until August 2006, indicates the highest concentrations at Site 93 are found in monitoring well MW-06. Also, that PCE concentrations in the target area have consistently increased; while the TCE, cis-1,2-DCE, trans-1,2-DCE and VC concentrations have remained relatively stable. The natural attenuation evaluation performed in 2001 revealed a limitation in reductive dechlorination. As part of the FS, a USEPA predictive modeling program, BIOCHLOR, was run by CH2MHill to evaluate contamination movement at the site. BIOCHLOR is a screening model that simulates remediation by natural attenuation of dissolved solvents at chlorinated solvent release sites. According to the model results, a no action scenario would require 14 years to reach a steady- state condition, and would result in chlorinated solvents impacting Edwards Creek. The model was run assuming a 90% reduction in the concentrations of chlorinated volatile organic compounds. Based on these parameters, a steady-state condition would be reached in 7 years and concentrations would be below the 2L standard within 450 feet of the source. The FS report (CH2MHill, 2005) evaluated five alternatives to remediate Site 93. The alternatives were: 1) No Action; 2) Permeable Reactive Barrier (PRB) Installation and Monitored Natural Attenuation (MNA); 3) In -Situ Chemical Reduction and MNA; 4) In -Situ Chemical Oxidation (ISCO) and MNA; and 5) Air sparging and MNA. 1.3.7 Proposed Remedial Action Plan (2006) The Proposed Action Plan, prepared by CH2M Hill in 2006, identified the Preferred Alternative as ISCO with MNA. The ISCO would include injection of permanganate in a 200 foot by 100 foot target area to promote chemical oxidation; other areas of the site would be addressed via long term MNA. The Preferred Alternative would have the potential to achieve the Remedial Action Objectives (RAO) for the site: Reduce COC concentration in the source area; 2. Prevent human ingestion of water containing the COCs at concentrations above 2L standards or MCLs, whichever is more conservative. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 1-4 October 2008 Throughout the implementation of the remedy, the Navy would restrict access as necessary to prevent unacceptable risks to human receptors from exposure to contaminants in the groundwater. Land Use Controls (LUCs) for Site 93 would be implemented to prohibit withdraw and /or future use of water, except for monitoring from the aquifers (surficial and Castle Hayne) within 1,000 feet of the identified groundwater plume. The LUCs would also prohibit intrusive activities within the extent of current groundwater contamination unless specifically approved by both NCDENR and USEPA. The LUCs would require filing a Notification of Inactive Hazardous or Waste Disposal per North Carolina General Statute (NCGS) 130A-310.8. 1.4 PRIOR REMOVAL OR REMEDIATION ACTIVITIES The only prior removal activity occurred in December 1993, when the 550—gallon UST was removed from the site. The removal included the tank and any contaminated soil that was visible at that time. The removal was performed under the UST program. The site was transferred to the Installation Restoration (IR) Program in 1998 due to the presence of chlorinated VOCs. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 1-5 October 2008 2.0 OPERABLE UNIT BACKGROUND This section of the IRACR provides background information on the ROD and RD for Site 93 at MCB Camp Lejeune. 2.1 RECORD OF DECISION (ROD) REQUIREMENTS 2.1.1 Description of the Selected Remedy The Proposed Remedial Action Plan's (PRAP) preferred alternative was in -situ chemical oxidation (ISCO) using potassium permanganate (KMn04) injected over a 200 foot by 100 foot target area at Site 93. ISCO was to be implemented within the targeted shallow groundwater zone in the area exhibiting the highest concentration of total chlorinated chemicals of concern (TCE, DCE isomers, PCE, 1,1,2,2 PCA and VC) within the 100 µg/L contour as shown in Figure 2-1. Other areas would be addressed through Monitored Natural Attenuation (MNA). Land Use Controls (LUC) for Site 93 would be implemented to prohibit the withdrawal and /or future use of water except for monitoring from the aquifers (surficial and Castle Hayne) within 1,000 feet of the identified groundwater plume. The ROD presented the remedy selected by the PRAP, ISCO via permanganate injection of the 200 foot by 100 foot target area and MNA for untreated areas to address groundwater contamination at Site 93. LUCs for the groundwater would be maintained for as long as required to prevent unacceptable exposures to contaminated groundwater or to preserve the integrity of the remedy. The chemical oxidation treatment would be performed by injecting permanganate into 200 Direct Push Technology (DPT) borings within the targeted 200 foot by 100 foot treatment area. The oxidizing agent would be pushed into the groundwater table with potable water to distribute the chemicals. This technology required an estimated 460 pounds of potassium permanganate per injection boring for a total of 92,000 dry pounds of potassium permanganate to be injected into the treatment area. The estimated time frame for completing the injection per the ROD was 30 to 35 days (using 2 injection rigs) or 50 to 55 days (using one rig), depending on conditions encountered in the field. The Navy, MCB Camp Lejeune, USEPA and NCDENR agreed that the injection of the permanganate would be a "one time" approach (assuming residual impacts will be addressed by MNA). Groundwater monitoring will be conducted on a quarterly basis for the first year upon Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 2-1 October 2008 completion of the target area treatment and annually thereafter. Ground water monitoring well samples would be analyzed for VOCs and NAIP. The duration of the monitoring would be assessed during the 5 year remedy reviews. Throughout implementation of the remedy, the Navy will utilize LUCs to prevent potential unacceptable risks to human receptors from exposure to contaminants in the groundwater. LUCs will be implemented and maintained by the Navy within the boundaries of Site 93 until concentrations of hazardous substances in the groundwater have been reduced to the levels that allow unlimited exposure and unrestricted use. The LUCs will meet the following objectives: • Prohibit withdraw of groundwater except for environmental monitoring from the aquifers (surficial and Castle Hayne) within 1,000 feet of the groundwater plume. • Prohibit intrusive activities within the extent of the current groundwater. contamination unless specifically approved by both NCDENR and USEPA until RAOs are achieved. • Maintain the integrity of any current or future remedial or monitoring system such as monitoring wells. Specific types of LUCs to be employed for these purposes will include: 1) incorporating land use prohibitions into the MCB Camp Lejeune Base Master Plan; 2) a deed Notice of Inactive Hazardous substance or Waste Disposal filed in Onslow County real property records per North Carolina General Statutes (NCGS) 130A-310.8; and 3) deed restrictions included in any deed transferring any portions of Site 93 to any non federal transferee. The Navy will develop and submit to the USEPA and NCDENR, in accordance with the FFA and the schedule in the SMP, a groundwater treatment Remedial Action Work Plan (Remedial Design document) and a LUC RD. The LUC RD will provide for implementation and maintenance actions, including periodic inspections and reporting. The Navy will implement, maintain, monitor, report on and enforce the LUCs according to the RD. 2.1.2 Selected Cleanup Goals Applicable cleanup goals for groundwater at Site 93 included objectives derived from the BIOCHLOR model with source reduction and monitored attenuation to reach steady-state conditions at or below the North Carolina Water Quality Standard (2L Standard). The 2L Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 —Site 93 2-2 October 2008 Standard has existing values for the chlorinated chemicals of concern in groundwater. Cleanup goals for groundwater COCs are as follows: • PCE 0.7 µg/L • cis-1,2-DCE 70 µg/L • trans-1,2-DCE 70 µg/L • TCE 2.8 µg/L • VC 0.15 µg/L. • 1,1,2,2 TetraChloroethane (PCA) 0.17 µg/L 2.2 REMEDIAL DESIGN SUMMARY The Remedial Action Basis of Design (RD) prepared by Shaw in October 2006 provided a work plan, basis of design, field procedures, sampling and analysis plan, Health and Safety Plan and schedule for implementation of the ISCO remedy. The ROD defined the treatment area and the proposed method of injection for the chemical oxidant. ISCO entails injecting an aqueous solution of an oxidant into the subsurface soil/aquifer matrix, resulting in the chemical oxidation of the constituents of interest. The oxidant is typically injected through screened well intervals or discrete injection tips and can be applied to both unsaturated and saturated soils. ISCO has been successfully applied to many different lithological environments, including sand, silts, and porous limestone. KMn04 (Potassium Permanganate) was selected as the oxidant of choice for this corrective measure. KM1104 offers the following advantages over other oxidants: • KMn04 quickly and completely oxidizes chlorinated ethenes to innocuous end products over a wide pH range. Reaction half-lives are between 1 minute (trans-1,2-DCE) and 4 hours (PCE) (Yan and Sewartz, 2000). • A visible (purple) solution makes it easy to track the injection influence or the degree of treatment. • KMn04 is chemically stable in groundwater; stays in solution until it is reacted. • No off -gas treatment is required. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 2-3 October 2008 Permanganate is relatively easy to handle, being essentially nontoxic and non -hazardous at the 2 to 3 percent concentration in solution typically used under field conditions. Minimal energy and equipment are required. Proven effective for the in -situ treatment of chlorinated ethenes at other Shaw -managed sites. The balanced chemical equations for permanganate oxidation of chlorinated ethenes are as follows: PCE: 4KMnO4 + 3C2C14 + 4H2O ---> 6CO2 + 4MnO2 + 4K+ + 12C1- + 8H' TCE: 6KMnO4 + 3C2HC13 � 6CO2 + 6MnO2 + 6W + 9C1- + 3 H' DCE: 8KMn04 + 3C2H2C12 6CO2 + 8MnO2 + 8W + 6Cl- + 20H- + 21­12O VC: I OKMnO4 + 3 C2H3C1 6CO2 + 1 OMnO2 + 1 OK F + 3CI- + 70H- + H2O As can be seen from these equations, the lower the degree of chlorination, the more permanganate is required to oxidize the chlorinated ethene. Nevertheless, the lower the degree of chlorination, the faster the reaction rate between permanganate and the chlorinated ethenes (Yan and Sewartz, 2000). In addition to addressing the contaminants, permanganate will also oxidize organic matter and reduced metal species in the soil/water matrix. The permanganate demand required to oxidize the soil matrix (i.e. organic matter and reduced metal species) is called the soil oxidant demand (SOD). KMn04 is a dark purple, odorless, nonvolatile, granular solid with a metallic luster. It has a specific gravity of 1.039 and a bulk density of 100 pounds per cubic foot. KMn04 has been certified by the National Sanitation Foundation to American National Standards Institute/National Science Foundation Standard 60 for drinking water treatment. The standard electrode potential for KMn04 is 1.68 volts, which makes it slightly weaker as an oxidant than hydrogen peroxide (with a standard electrode potential of 1.78 volts). KMn04 is fairly soluble and can easily be mixed in solution up to a concentration of 3 percent under field conditions. The effectiveness of treatment is a function of three elements: the contact between the oxidant and the contaminant(s), the kinetics of the reaction between the permanganate and the contaminant, and competitive reactions of permanganate with the SOD. If the contaminants targeted for ISCO are reactive (e.g., chlorinated ethenes) and sufficient oxidant has been added to overcome the SOD, the limiting factor to the successful application of ISCO is the transport of Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 2-4 October 2008 the oxidant to the areas of contamination, and not the rate of reaction between the permanganate and the contaminants. Compared to the time to transport the permanganate to the treatment zone, the oxidation of chlorinated ethenes by permanganate is essentially an instantaneous reaction. By contrast, travel times for the permanganate to migrate away from the injection point may be several hours or days, depending on the spacing of the injection points, the rate of injection flow, and site lithology. Residual permanganate will physically stain the soil and groundwater until such time that groundwater flow carries sufficient chemically reduced species into the treatment area to consume the permanganate. Short-term water quality changes in color or total dissolved solids are to be expected following the application of permanganate. KMn04 reacts rapidly with the double bonds in chlorinated ethenes such as PCE, TCE, DCE isomers, and VC. Several field -scale and full-scale applications have demonstrated that injection of permanganate solutions into soils containing chlorinated ethenes results in substantial in situ destruction of these compounds. KMn04 reacts with the chlorinated ethenes, resulting in the innocuous breakdown products carbon dioxide, chloride ions, and manganese dioxide. The ROD had proposed using Direct Push Technology (DPT) to inject the permanganate and water into the subsurface. Shaw proposed using injection points and a gravity feed injection system in the RD because of the anticipated cost of the operation and the unknown hydraulic condition of the treatment area. Due to the shallow water table and the shallow area requiring treatment, Shaw did not believe the Geoprobe would be able to inject the reagent into the sub- surface without the reagent forcing its way to the surface and thereby limit the exposure to / mixing with the contaminated ground water. The treatment area was defined as the area where the shallow groundwater zone possessed a VOC concentration total exceeding 100 µg/L. The areal extent of the permanganate treatment area was estimated at approximately 20,000 square feet (ft2). A design radius of influence (ROI) of 5-ft was selected based on results obtained from the permanganate injection in the shallow zone at a similar sites (Site 35 and Site 86). Using a 5-$ ROI, the spacing between injection points was determined to be 10-ft. The 10-ft spacing between injection points was applied to the entire treatment zone. A minimum spacing of 5 feet was maintained between injection points and existing monitoring wells and utilities to prevent short-circuiting of the injected solution to the surface around the outside of the well annulus or via the well casing or the utility annulus. It was necessary to move several injection points to maintain clearances for building access, Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 2-5 October 2008 utilities, or monitoring wells. The injection points were moved to the south and east to form additional columns and rows. Based on the treatment area of approximately 20,000 ft2, and a radius of influence for each injection point of 5 feet, a grid layout with 200 injection points was used to cover the area. 2.3 MATERIALS COMPATIBILITY KMn04 has specific material compatibility limits. A data sheet that itemizes the materials compatibility was provided in the RD. KMn04 will react adversely with galvanized metal under neutral conditions and almost any ferrous metal (e.g., carbon steel, iron) under acidic conditions. Stainless -steel is the one exception, and is suitable at any pH with 304 and 316 stainless -steel being preferential. As with ferrous metals, brass, bronze and aluminum are acceptable at neutral conditions but will corrode under acidic conditions. Most thermoplastics are acceptable with permanganate with the exception of polystyrene. PVC is considered a good material choice up to 140°F. Acceptable hose, tubing, and gasket materials up to this temperature are CPVC, Hypalon, Tygon, PVDF, Teflon, and Viton. Rubber and neoprene are unacceptable materials. The injection components were constructed primarily of cross -linked HDPE tanks, PVC piping and hosing, stainless -steel appurtenances, and PVDF or Teflon gaskets. No rubber hoses, carbon or galvanized steel piping, or unsuitable gasket or seal materials were used. 2.4 MASS OF KMN04 The total mass of KMn04 required to meet the SOD was calculated by applying the design 5 g KMn04/kg of soil to the mass of aquifer materials within the treatment area. The total amount required was calculated at 92,000 lbs. The initial design for this site was predicated on injecting the reagent equally into each of the points. The KMn04 demand for each injection point with the same screened interval length is identical; injection points with an 8-ft screen assuming a 1 to 2 gpm injection rates was expected to deliver approximately 1,985 gallons of reagent per point. The KMn04 mass was injected into the subsurface as a dilute (2-3%) solution which was prepared on -site using hydrant water and solid phase pharmaceutical grade (USP) KMn04 purchased from Carus, Inc. Based on the total KMn04 demand, 92,000 lbs of USP grade KMn04 would be delivered in reusable 250 gallon plastic totes. A dry chemical mixing system was rented from Carus and used to convert the dry KMn04 into solution. The solution was prepared in batches using a 1,600 gallon mixing tank prior to injection. Additional injection details are provided in Sections 5.0 and 6.0. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 2-6 October 2008 The volume of KMn04 solution required for each injection point was calculated assuming the injection of one pore volume into the zone of influence of each injection point (5-ft ROI, varying vertical thickness, and a porosity of 0.30). The total volume of KMn04 solution to be injected via 200 injection points is approximately 397,000 gallons. 2.5 INJECTION SEQUENCE, INJECTION RATES, AND HYDRAULIC CONTROL The ROD had proposed using a DPT to inject the permanganate and water into the subsurface. Shaw proposed using injection points and a gravity feed injection system in the RD because of the anticipated cost of the operation. Due to the shallow water table and the shallow area requiring treatment, Shaw did not believe that DPT would be able to inject the reagent into the sub- surface without the reagent forcing its way to the surface and thereby missing the opportunity to mix with the contaminated ground water. The injection system consists of two, four point manifold systems that delivered the reagent via pumps to 8 selected points at one time. To complete the injection, 25 phases of 8 points per phase for a total of the 200 points were proposed. The injection would commence on the western edge of the treatment zone and move east across the site with the direction of groundwater flow. The anticipated injection rate at this site was estimated from historical groundwater recovery rates at approximately 0.1 gallon per minute (gpm) per foot of injection point screen. Hence, the anticipated injection rate into the points with an 8-ft screen was 1 to 2 gpm. Assuming an average injection time of 8 hours per day, the estimated time to complete each injection phase was to range from two to four field days. 2.6 CONCENTRATION OF KMN04 INJECTION SOLUTION The target in -situ concentration of the KMn04 solution calculated from the total mass demand and the pore volume was 2.6 percent. The approach to achieve the target in -situ concentration was to inject one pore volume of permanganate solution at a concentration of 2.6 percent. The 2.6 percent permanganate solution was recommended by Shaw technical experts and permanganate suppliers to avoid screen clogging problems that a 5 — 6% solution injection had been known to cause. 2.7 SOIL OXYGEN DEMAND The Soil Oxygen Demand (SOD) test provides an indication of the amount of permanganate ion that will be consumed by the organics, iron, and other native reductants in the aquifer media. These constituents have been shown to be the overriding factor in total permanganate Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 2-7 October 2008 consumption on many sites. SOD tests were conducted at Site 35 and Site 86 by CH2MHill. The results of the SOD test reflect both soil matrix and contaminant demand. This combined demand test provided a realistic check of the overall permanganate consumption to be expected on a unit basis at full scale. The SOD was estimated by Shaw at 5 g KMn04/kg of soil for the Site 93 treatment area. 2.8 SITE GEOLOGY Site 93 is located in the Atlantic Coastal Plain physiographic province of North Carolina. The sediments of the Atlantic Coastal Plain consist of interbedded sands, clays, calcareous clays, shell beds, sandstone, and limestone. The MCB is underlain by seven sand and limestone units separated by units which are comprised primarily of silt and clay. These include the surficial, Castle Hayne, Beaufort, Peedee, Black Creek and the upper and lower Cape Fear lithologic units. The combined thickness of these units is approximately 1,500 feet. The Undifferentiated Formation is comprised of loose to medium dense sands and soft to medium stiff clay. This formation is comprised of several units of Holocene and Pleistocene ages and can consist of a fine to coarse sand, with lesser amounts of silt and clay. At Site 93, this formation typically extends to a depth between 20 and 30 feet. Overall, the Undifferentiated Formation (surficial aquifer) appears to lie immediately above the River Bend Formation (upper portion of the Castle Hayne aquifer) with little to no presence of the Belgrade Formation (Castle Hayne confining unit). The inconsistent nature of the Belgrade Formation suggests that a significant hydraulic connection exists between the Undifferentiated Formation (surficial aquifer) and the upper portions of the River Bend Formation (Castle Hayne aquifer). At best, the Belgrade Formation at Site 93 can be classified as a semi -confining unit or a "retarding layer" as it is laterally discontinuous and does not exhibit completely confining conditions to the River Bend Formation below (Castle Hayne aquifer). Beneath the Undifferentiated Formation and the limited Belgrade Fonnation lies the River Bend Formation (upper portion of the Castle Hayne aquifer). This unit, which is predominately composed of dense to very dense shell and fossil fragments interbedded with calcareous sands, is present at approximately 25 to 50 feet bgs. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 2-8 October 2008 2.9 SITE HYDROGEOLOGY The surficial aquifer resides within the Undifferentiated Formation. The Castle Hayne confining unit resides within the Belgrade Formation. The Castle Hayne aquifer resides within the River Bend Formation. The thickness of the surficial aquifer varies from 18 to 23 feet and the thickness for the Castle Hayne Confining Unit varies from 4 to 7 feet, although a definite confining layer, which separates the surficial aquifer from the Castle Hayne aquifer, is not present at Site 93. During the RI, groundwater levels within RI monitoring wells ranged from 2.15 feet below msl to 13.52 feet above msl. During groundwater sampling activities conducted in January 2005 as part of the Supplemental Site Investigation, groundwater levels ranged from 7.93 to 12.97 feet above msl. The summer 2006 groundwater elevation data and approximate flow directions have been illustrated on Figure 2-2. The groundwater elevation data suggest that the flow patterns observed for the surficial and upper portions of the Castle Hayne aquifer display similar trends. Overall, elevations are higher in the northern portions of Site 93, with decreasing elevations in the directions of Edwards Creek and the wooded area to the east. Groundwater flow in the surficial aquifer flows to the east toward Edwards Creek, which serves as a groundwater discharge boundary. Edwards Creek effects flow within the surficial aquifer more than in the deeper portions of the aquifer. Groundwater flow in the upper portions of the Castle Hayne is affected somewhat by the local discharge area of Edwards Creek. The New River, located east of Site 93, apparently influences the groundwater flow of the deeper portions of the Castle Hayne aquifer, causing groundwater at depth to move east, toward the river. The hydraulic conductivity (K value) at Site 93 is estimated to be similar to the K value at Site 89. During the RI, the average hydraulic conductivity in shallow wells at Site 89 was 8.4 feet/day; and the average hydraulic conductivity in the intermediate well at Site 89 was 64.6 feet/day, nearly one order of magnitude greater than the shallow wells. The hydraulic gradient at Site 93 was estimated at approximately 0.004 ft/ft. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 2-9 October 2008 3.0 REMEDIAL ACTIONIMPLEMENTATION This chapter describes the activities performed to implement the ISCO component of the selected remedy at Site 93. The scope of work (SOW) for the Remedial Action at Site 93 included the following activities: • Mobilization of Equipment and Personnel • Site Preparation • Utility Clearance • Injection Well Installation • Permanganate Injection System Setup • Permanganate Injection and Operational Monitoring— Phase 1 • Monitoring well pump test • In Situ Performance Monitoring and Post Injection Monitoring • Permanganate Injection / Site Dewatering and Operational Monitoring— Phase 2 • Completion Report and Remedial Action Progress Reports. The chronology of events for the remedial action implementation is presented in Table 3.1 Photographs of the Remedial Action Implementation are presented in Appendix D. 3.1 SITE PREPARATION AND UTILITY CLEARANCE Site 93 was readily accessible, and the surface was suitable for setup of a DPT drill rig for installation of the injection points. No site clearing and only minimal grading was required to provide a stable, flat surface for setup of the permanganate injection system and the secondary containment. Site preparation for the mixing/injection system required a backhoe and gravel to establish a suitable surface base for the equipment. A 6 mil plastic liner was installed over the equipment area and confining berms were established using hay bales with the plastic laid over top of the bales. This provided a secure, contained area for the mixing operation and eliminate the potential for leakage of permanganate from the mixing area. The nearby fire hydrant was used as a water source for makeup water to mix the penmanganate solution for the Phase 1 operation. The location of underground utilities were identified and marked prior to injection point installation. The existing monitoring well locations were identified. Five of the existing monitoring wells were identified for the remedial action network. And five additional monitoring point locations were identified and the monitoring wells installed. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 3-1 October 2008 3.2 INJECTION POINTS LAYOUT The treatment area was defined as the area where the shallow groundwater zone possessed the highest VOC concentration within the contour exceeding 100 µg/L. The areal extent of the permanganate treatment area was estimated at approximately 20,000 square feet (ft2), and is depicted in Figure 3-1. A design radius of influence (ROI) of 5-ft was selected based on results obtained from the permanganate injection in the shallow zone at a similar sites (Site 35 and Site 86). Using a 5-ft ROI, the spacing between injection points was determined to be 10-ft. The 10- ft spacing between injection points was applied to the entire treatment zone. A minimum spacing of 5 feet was maintained between injection points and existing monitoring wells and utilities in order to prevent short-circuiting of the injected solution to the surface around the outside of the well annulus or via the well casing or the utility annulus. It was necessary to move several wells to maintain clearances for building access, utilities, or monitoring wells. The injection points were moved to the south and east to form additional columns and rows. Based on the treatment area of approximately 20,000 ft2, and a radius of influence for each injection point of 5 feet, a grid layout with 200 injection points was used to cover the area. The layout of the 200 injection points is depicted on Figure 3-1. The injection points were numbered in sequential order from west to east and north to south and were identified as A.06 through K.21. An updated hydrogeological cross section which includes the information obtained from MW031W, ISO4A, IS13A and MW05IW drill logs was used to identify the depth intervals of the shallow groundwater zone requiring ISCO treatment. Although the surface topography and the depth of the shallow groundwater zone vary within the treatment area, the proposed length and location of the injection point screens were set as standard. The injection points were screened from 6 to 16 feet bgs, relative to surface topography, with a 2-foot thick grout cap installed from the surface down. 3.3 INJECTION POINT INSTALLATION AND DEVELOPMENT All 200 injection points were installed in the shallow groundwater zone using a 3.25-inch DPT rod. The work began in early October 2006 and finished in mid October, 2006. The location for each injection point and the ground water monitoring wells are summarized in Figure 3-1. The points were installed to a depth 16 feet bgs across the permanganate treatment zone. Since the subsurface lithology had been adequately described during previous borings, detailed boring logs were not completed during injection point installation. Each injection point was constructed of 1.25-inch inside diameter (ID) continuous wrapped 0.020 inch slot screen with a 1.25-inch ID riser comprised of Schedule 40 PVC. A filter pack consisting of 20/40 filter sand was placed Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 3-2 October 2008 around the screen from the bottom of the borehole to at least 2 feet above the screen. The filter pack was completed with a I-ft lift of fine sand (30150 grade) intended to prevent infiltration of the bentonite seal into the underlying 20/40 sand. Pure Gold Tm bentonite and cement grout were used to seal the annular space above the filter pack. The seal extended from the top of the filter pack to the ground surface. All injection points were completed with at least a 6-inch stick-up above ground surface to enable fitting the risers with the injection system via a cam lock fitting. No surface protective casing was installed, however, a fence was installed around the treatment area prior to injection point installation. An injection point construction diagram is presented in Figure 3-2. Only limited development of the injection points was performed to establish hydraulic connection with the natural formation. The duration of development was less than one hour per injection point. Following installation, Shaw used a GPS unit to determine the horizontal locations of the new monitoring wells and the corners of the treatment area. All horizontal coordinates were recorded to an accuracy of 0.10 feet within the state plane coordinate system using two horizontal coordinate systems [North American Datum of 1927 (NAD 27) and NAD 83]. Vertical elevations of the injection points will not be surveyed, because these points will not be used as typical monitoring points. Remediation Derived Waste (RDW) was managed and disposed as outlined in the Basewide QAPP. The RDW generated from the injection points installation effort consisted of removed soil, injection point development fluid, purge water from sampling activities, decontamination fluids, spent injection points materials, and PPE. Additionally, debris, and PVC pipe cuttings were properly disposed at the MCB landfill. 3.4 PRE -INJECTION GROUNDWATER SAMPLING Numerous LTM sampling events have been conducted at the site since completion of the RFI, with the most recent event completed in January 2005. The LTM events have provided groundwater data that indicate an increase in PCE and a stable reading for TCE, cis-1,2-DCE, trans-1,2-DCE, and VC concentrations. Shaw performed a baseline groundwater monitoring event to determine pre -injection conditions in mid October, 2006. This sampling event included 5 existing wells and 5 new wells installed during October 2006 while the injection points were being installed. The existing wells (06, 08, 09, 12, and 05) and the newly installed wells that were sampled are shown on Figure 3-2. The pre -injection sampling results are presented in Table 6.1 Interim remedial Action Completion Report Project 120348 Operable Unit No. 16- Site 93 3-3 October 2008 3.5 PERMANGANATE INJECTION SYSTEM MOBILIZATION AND SETUP The permanganate injection was implemented using a modular, automated hatching plant. The modular system consisted of a weighing/mixing unit and manifold system capable of injecting into 8 points simultaneously. The KMn04 solution was prepared on site at the design injection concentration of 2.6% by mixing a dry, free -flowing USP grade KMn04 solid with water. This solution was continuously re -circulated to keep the permanganate ion (Mn04) in solution. The injection system equipment was mobilized to the site, including the components of the injection trailer, and consisted of the following components: • Dry chemical injector system (supplied by Carus, Inc.) with a booster pump • 1,600-Gallon high -density polyethylene solution mixing tank • 1,600-Gallon high -density polyethylene solution holding/recycling tank • Booster Pump, 3 horsepower, single phase • Slurry make-up system with volumetric feeder bin • Injection pre -manifold with totalizing flow meter, and pressure gauge • Injection manifold for an 8-point system. • 1,000 feet of clear PVC braided hose • 8 injection point connectors Figure 3-3 illustrates these components in a process flow diagram. Secondary containment was established around the components of the injection system. An industrial forklift was mobilized to the site primarily to set the equipment and move the 1500 lb KMn04 bins. The USP grade KMn04 was delivered in 250-gallon plastic bins of free -flowing material from the Carus, Inc. manufacturing plant in Peru, Illinois. A total of 61 bins, each weighing 1500 lbs (92,000 lbs), were to be delivered. Shaw requested partial shipments to minimize storage requirements. The dry KMn04 bin was set on the mixing area and connected to the chemical feed system. The KMn04 mix/feed injector system was pre -wired and pre -plumbed on a skid. The bin was set in place and connected and when the system was initiated, the correct weight of dry reagent was mixed with the proper amount of water for a 2.6% solution. Once the KMn04 solution had been thoroughly mixed at the target concentration, the solution was conveyed from the 1,600 gallon holding/recycling tank to the injection feed pump. Rigorous material handling protocols were in place, along with secondary containment for the entire system. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 3-4 October 2008 3.6 SECURITY Following installation of the injection points, a high -visibility, 4 foot high plastic fence was installed around the treatment area for security concerns and to keep the occasional trespassers out. Figure 3-1 presents the footprint of the fence, and indicates the locations of the injection points and the mixing / injection system, which were within the fence boundary. Interim remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 3-5 October 2008 4.0 PHASE 1 INJECTION OCTOBER, 2006 THROUGH FEBRUARY, 2007 This section describes the activities performed to implement the ISCO component of the selected remedy at Site 93 for the Phase 1 period of October 30, 2006 through February 12, 2007. All field activities were conducted in accordance with the Site -Specific Safety and Health Plan (SSHP) and the Quality Assurance Program Plan (QAPP) provided in the Basis of Design (Shaw 2006). During this period, Shaw injected approximately 92,000 gallons of reagent into the subsurface. Photographs of the Remedial Action Implementation are presented in Appendix D. 4.1 PERMANGANATE INJECTION SYSTEM OPERATION 4.1.1 Permanganate Solution Mixing The permanganate solution was prepared on a batch basis of about 1600 gallons which allowed continuous injection from the feed tank over the course of the field day. The concentration of the injected solution was not altered from one day to the next. Once the solution was thoroughly mixed at the design concentration, 2.6%, the solution was be transferred to the oxidant feed tank using the injector pump. Once in the feed tank, the reagent was re -circulated by the pump to maintain the concentration. A second batch could be made when necessary without impacting the first batch. 4.1.2 Permanganate Solution Injection The recirculation/injection pump was used to pump the permanganate solution from the feed tank to the 8-point manifold, and then to 8 injection points. Each injection lateral off of the manifold had a direct readout totalizing flow meter, pressure gauge, check valve, and a ball valve. The flow was transmitted from each lateral to a hose assembly that connected to the injection point. Each assembly had a pressure gauge and a pressure release ball valve. The manifold lines were connected to the injection point via clear PVC braided hose and cam lock fittings. The injection pumping system delivered the permanganate solution to two sets of four injection point manifolds. Shaw initially estimated that at an average injection time of 8 hours per day, the time to complete each injection phase was estimated to range from three to four field days per well at the anticipated injection rate of 2 gpm. Shaw controlled the pump output to insure the injection pressures were maintained below 5 lbs per square inch (psi) or essentially gravity feed at the injection point to prevent soil fracturing or Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 4-1 October 2008 the formation of preferential flow paths to the surface. Any permanganate discharges from the injection points were allowed to infiltrate back into the subsurface should they occur within the treatment area. Permanganate discharges that were leaving the treatment area were neutralized with a vinegar and peroxide solution. A mixture of dilute hydrogen peroxide, vinegar, and water was used to neutralize any KMn04 spilled outside of the treatment area, the injection system, or on PPE. The neutralizing solution was prepared by mixing one part water, one part hydrogen peroxide (3 percent concentration), and one part vinegar. The hydrogen peroxide and vinegar solutions are produced for home -use and are readily available at local drug and convenience stores. Neutralizing the KMn04 with the hydrogen peroxide/vinegar solution transforms the purple solution containing the permanganate ion into a brown precipitate of manganese dioxide. Further addition of hydrogen peroxide and vinegar will transform the manganese dioxide to the Mn2+ ion, which forms a colorless solution in water. The flow and pressure to each injection point was modified during the injection within the limitations imposed by the lithology. The real-time performance monitoring during injection was used to provide feedback for any operational changes, such as changing the concentrations of the injection solution the operating pressure, and the delivery rate. The initial intent of the plan was that KMn04 injection would continue until the design KMn04 mass loading and hydraulic loading of the area was achieved. Shaw soon learned that the actual volume injected each day would not match the mathematical models and the daily volume varied depending on the antecedent site moisture conditions, observed injection flow rates / injection point acceptance rate, the injection duration and the lithology of the site. Shaw intended to treat the area by dividing it into quadrants defined by 5 columns of injection points. The treatment area was approximately 20 points wide by 10 points deep. The treatment area was divided by wide with about 5 columns of wells per quadrant. Shaw initially installed 8 hoses that extended from the recirculation tank to the injection points. Once the system was set up and as part of the start-up testing, Shaw began by injecting water into the injection points to ensure proper operation of the entire system. All went well with the "wet start-up" and Shaw proceeded to operate the system with permanganate. Shaw began injecting at the 1-2 gpm rate and flooded the injection points and incurred substantial "day lighting" / break out of the reagent at the surface. Shaw reduced the pump rate to the point that essentially the reagent was being gravity fed into the injection points which resulted in flow rates Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 4-2 October 2008 of 0.3 to 0.5 gpm. The subsurface materials could not accept the 1-2 gpm flow which caused the excess flow to drain over the treatment area. Shaw performed daily inspections of the treatment area monitoring reagent break-out, inspecting the monitoring points for any purple color that would indicate the reagent had traversed to that point, inspecting the injection point for break out and to move the hose to another injection point, and performing selected field monitoring tests. Shaw would move the 8 hoses around to different injection points within the treatment quadrant as necessary to maintain the injection rate. Some points would be able to accept the 0.3 gpm rate for the day, other for only a few hours and then break out would occur. At that point, Shaw would move the hose to a new injection point within the quadrant. Shaw initially injected in each well within the quadrant, but leaving several open points between injection points to allow the reagent to mound and flow out of the injection area. 4.1.3 Operational Monitoring The following system parameters were intended to be monitored during the injection: flow rates, total KMn04 mass injected, total KMn04 solution volume injected, manifold pressures, wellhead pressures, and KMn04 concentration of the injected solution. Changes in flow rates and pressure were to be recorded during the injection to document the effect of fluid injection on the site - specific lithology. Observations were also to be recorded regarding any solids fouling in the point screens or process piping. During the injection, select monitoring and recovery wells were to be monitored for parameters indicating the distribution of the permanganate solution. In particular, the following were used as indicator parameters: oxidation-reduction potential (ORP), conductivity, presence of purple/pink water as an indication of KMn04, and visual presence of brown suspended particles as an indication of manganese dioxide. In addition, the depth to water in the selected wells was monitored to provide an indication of the extent and duration of groundwater mounding. During each injection phase, a set of monitoring and/or injection points were to be monitored for the aforementioned parameters. Much of this monitoring was revised once the flow rates and flow pressures (gravity feed) were determined to be so low for the area. Site personnel completed field activity daily logs (FADL) to document site activities. Information recorded in the FADLs included narratives of the activities that occurred during that day consisting of the personnel on site, daily progress of the injection, samples that were collected and shipped, daily equipment maintenance, a record of decisions made, and current action items. Copies of the FADLs are included in the project records. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 - Site 93 4-3 October 2008 4.1.4 Operational Problems and Adjustments The implementation of the ISCO using KMn04 posed operational problems of different scales. In keeping with a flexible design strategy, several contingencies were pre -planned to maintain the operational performance. But several adjustments to the operational sequence were required due to site conditions that caused a much slower injection rate. The following adjustments were made once the operation started: 1. The estimated injection rate of 1-2 gpm per well was not possible due to the subsurface conditions. This flow rate flooded the injection point and caused break- out of the reagent from the sub surface. Shaw was only able to attain an inflow of 0.3 to 0.5 gpm for Phase 1. 2. Shaw was anticipating minimal break out of the reagent from the sub surface, but it became a daily occurrence during the Phase 1 work. The sub -surface would not accept the original flow rate and Shaw was constantly adjusting the rate down and moving the hoses to other injection points. 3. Shaw estimated 90 days to inject 398,000 gallons of reagent. During the first 90 days, Shaw injected 92,000 gallons of reagent due to site sub surface conditions. The injection rate was limited primarily by a high existing water table and low soil permeability. 4. All reagent was injected under gravity feed at a rate of 0.3 gpm; a pressurized injection was not possible as it would have caused a "blow out of the sub surface soil materials". 5. Shaw increased the injection system from 8 points to 16 points by providing "Ts" at the end of the manifolds. This was possible due to the gravity feed and not a pressurized feed which may have put more demand on the pump. 6. The injection of KMn04 into the subsurface caused localized groundwater mounding in the treatment zone that typically developed rapidly. The mounding / surface break outs occurred quickly and it was not possible to avoid KMn04 spills at the surface by monitoring water levels in surrounding wells and capping overflowing monitoring wells. Since the actual injection rates were less than I gpm per 1-ft of injection point screen, additional field time would be required to deliver the design volume of KMn04 solution. Gravity feed injection during nighttime hours was considered to compensate for time lost during daylight hours resulting from the lower than anticipated flow rates. But due to the potential for the reagent to migrate off site even under lighted conditions, this was not considered feasible. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 4-4 October 2008 8. Due to the low injection rate, monitoring of the injection pressure and well head pressures were not performed since this injection pressure was no more than gravity feed. The permanganate concentration was kept constant at 2.6% since potential clogging was a concern with the low injection rates and ground water flow rates. 9. Shaw initially believed that each well should receive the 2,300 gallons of reagent originally designed for each well. As time went on and the injection points appeared to have problems accepting the designed flow, Shaw believed that each quadrant should receive '/ of the total 398,000 gallons of reagent. This was later revised to the treatment area should receive the 398,000 gallons at whatever injection points would accept the flow due to the heterogeneity of the sub surface soils and the low permeability. 10. Although it was not anticipated that permanganate solution would be released to the drainage ditch east of the treatment area, during a site inspection of the area, Shaw personnel discovered a release from the sub -surface near the drainage channel that had flowed into the Edward's Creek. The injection system was shut down immediately and Shaw personnel responded to the material in the drainage channel. Shaw poured neutralizing solution into the drainage channel to remove the purple color and precipitate the permanganate. The neutralizing solution resulted in killing about 30 minnows downstream from the entry point. Shaw prepared an incident report and performed additional water quality analysis of the drainage channel water to confirm the neutralizing solution had dissipated and the area could now accommodate native fish. Preventative measures were implemented to avoid surface water contamination with permanganate solution in the event of an unforeseen release. Porous bags containing peat material were placed in the drainage channel to intercept surface water flow. Peat moss has a SOD two orders of magnitude higher than the SOD of the aquifer materials, and is effective in rapidly consuming permanganate. Any subsequent releases of permanganate to surface water were intercepted by the peat moss. 4.2 POST -INJECTION REVIEW As the injection period continued into the winter months / rainy season at Camp Lejeune, the natural water table came up to within a foot of the surface and made it exceedingly difficult to continue to inject reagent effectively into the subsurface, as there was no -where for the reagent to go but to the surface. During the injection period from November 2006 to January 2007, Shaw injected about 900 to 1000 gallons per day of reagent. In January 2007, Shaw requested that the ISCO remediation be temporarily shut down until drier weather prevailed, preferably May or June. Shaw also requested that a pump test be performed to evaluate the hydro -geologic flow Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 4-5 October 2008 characteristics of the area and to evaluate alternative delivery systems for the reagent. Shaw also requested that the ground water be sampled and analyzed to determine if the ISCO remediation was performing as planned. 4.3 SITE 93 PUMP TEST Shaw performed a pump test along the northern edge of the treatment area in April 2007. Shaw had worked for approximately 120 days during the Phase 1 work and had injected only 92,000 gallons of reagent. During the break between Phase 1 and Phase 2, Shaw requested that a pump test be performed to better define the hydro -geologic subsurface conditions at the site. Monitoring well MW-17 was used as the extraction well and other monitoring wells as well as the injection points were used to measure the drawdown. The pump test was used to clarify flow conditions and develop alternative injection procedures. The data sheets from the pump test are provided in Appendix C. The results of the pump test indicated a horizontal conductivity of 7 feet per day and a vertical conductivity of 0.1 feet per day. This data was used to develop alternative injection methods during the down time between Phase 1 and Phase 2. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 4-6 October 2008 5.0 PHASE 2 INJECTION JUNE, 2007 THROUGH DECEMBER, 2007 5.1 ADDITIONAL SITE EVALUATION Remedial action progress reports to document and track the progress of ISCO were presented at Partnering Team meetings. The progress reports discussed the operational concerns and the problems of the slow injection of reagent. The Baseline sampling and the February sampling event findings as they pertain to the performance and effectiveness of the selected remedy were reviewed during these meetings. In March 2007, Shaw performed a pump test using MW 17 as the extraction well and the adjacent monitoring wells and the injection points were used to determine the drawdown effects. The pump test was performed to determine the hydro -geologic characteristics for the treatment area and to develop flow parameters to evaluate alternative delivery methods. The results of the pump test are presented in Appendix C. The pump test yielded a horizontal conductivity of 7 feet per day while the vertical conductivity was 0.1 feet per day. Based on the hydro -geologic characteristics, Shaw modeled and evaluated three alternatives for delivery of reagent. The three alternatives were the original gravity feed injection at each injection point; an alternative using dewatering equipment to dewater the treatment area, mix the water with reagent and then inject the reagent into the sub surface; and an alternative using dewatering points to lower the water table and open trenches to deliver larger quantities of reagent. The evaluation (Appendix Q was presented to the Partnering Team and submitted to NCDENR for review. The evaluation selected dewatering and injection through the existing well points as the better operational method going forward. The model indicated the injection rate could be as high as 1 gpm for this system. The Partnering Team agreed with the recommendation and NCDENR granted a re -injection permit for the treated water on June 19, 2007. 5.2 PHASE 2 OPERATIONS Shaw began operation of the second phase of the ISCO injection on June 25, 2007 and continued the injection operations until December 17, 2007. The end date was determined during the November 2007 Partnering Meeting. At the end of the injection period, Shaw had injected another 144,000 gallons of reagent into the sub -surface for a total of 236,000 gallons, 60% of the design 398,000 gallons for injection. Photographs of the Remedial Action Implementation are presented in Appendix D. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 5-1 October 2008 Shaw rented a de -watering pump and associated hosing, and a portable tank to include in the equipment train. Half of the injection points were converted to dewatering points by installing a smaller diameter pipe inside of the injection point to pull the ground water from the lower elevations of the well point. The de -watering was performed on 3 rows of 10 points at a time starting from the west side. Every other well point was converted to a de -watering point and every other injection point was used for injection of reagent. The extracted water was pumped to the portable tank and used for the make-up water for the reagent. The intent was to remove the same amount of water that the injection operation was placing in the sub -surface. Thereby, Shaw would have minimal water to inject once the de -watering operation ceased. Shaw's intent was to achieve 1 gpm per well for extraction and injection per the design model. The sub- surface would not accept this injection amount, but Shaw was able to input about 1,500 gallons per day using 15 injection points with the de -watering assistance which was 50% more than the rate operating at gravity feed. Shaw operated the dewatering and injection system approximately 50 hours per week, 5 days per week, and 10 hours per day. The system did not operate on holidays. Shaw did not operate the system on days with high antecedent moisture in the ground, e.g. days of high rain intensity or after several days of rain because the water table at the site would rise and it would be difficult to get any reagent into the sub surface. Shaw divided the treatment area into 7 segments, each about 3 columns wide with each segment having about 15-16 extraction points and 15-16 injection points. Reagent was injected until break-out would occur over a large portion of the treatment segment. It usually took 5-10 days for this saturation point to occur; at that time Shaw would move the extraction headers and the injection hoses to the next treatment segment. Shaw performed three complete cycles across the treatment area. During the first two cycles, Shaw used the same injection points and dewatering points. On the third cycle, Shaw reversed the flow by converting the withdraw points to injection points and the injection points to withdraw points. The intent was to fully saturate the groundwater and subsurface soil with permanganate. The de -watering injection process stopped on December 17, 2007. The de -watering, mixing and process equipment were decontaminated and demobilized as noted below. 5.3 DECONTAMINATION and DEMOBILIZATION 5.3.1 Heavy Equipment Prior to demobilizing, the drilling equipment that contacted the interior of a borehole (including, but not limited to, drill rig, drill rods, bits, sampling equipment, and tools) was thoroughly Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 --Site 93 5-2 October 2008 cleaned at a temporary decontamination facility located on the site. The equipment was cleaned using steam or high-pressure hot water from a steam cleaner before setting up on the first borehole and following completion of the final borehole. Decontamination of drilling equipment was not required between injection point locations, since any potential cross -contamination would be neutralized by the injected oxidant. At the drill sites, cleaned equipment will be kept off the ground by storing on cleaned metal racks (not wooden pallets) or on polyethylene - covered pallets. Excess soil was removed from the drilling rig and support vehicles before pulling off a drilling site to prevent tracking soil throughout the site. The decontamination water and soil from the well points was containerized and properly disposed of. 5.3.2 Sampling Equipment All equipment that contacted samples was thoroughly cleaned prior to collecting samples. The decontamination procedure for cleaning stainless -steel sampling equipment included the following steps: • Wash equipment thoroughly with laboratory -grade detergent and water, using a brush to remove any particulate matter or surface film. • Rinse equipment thoroughly with potable water. • Rinse equipment thoroughly with analyte-free water. • Rinse equipment with isopropanol (allow to air dry). • Second rinse with analyte-free water. • Wrap equipment, if appropriate, in one layer of aluminum foil (shiny side exposed) to prevent contamination if equipment is going to be stored or transported. Roll edges of foil into a "tab" to allow for easy removal. 5.3.3 KMn04 Injection System After completing of the KMn04 injection in December 2007, the injection system components were rinsed with water until the "purple color" of the water disappears. The KM1104 solution generated during the decontamination process was flushed down the injection points to maximize the amount of KMn04 delivered to the treatment zone, and to minimize the amount of KMn04 disposed as remediation derived waste (RDW). The Mn02 is not soluble, and was removed via filter bag. The sludge was collected and disposed of as non -hazardous RDW. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 5-3 October 2008 5.4 POST -INJECTION MONITORING Post -injection groundwater samples were collected from the ten monitoring points analyzed for VOCs to evaluate the effectiveness of the selected remedy in achieving the 2L standards. Samples were collected on December 27, 2007 after completion of the injection and about three months later in March 2008. Chloride analysis was also conducted to provide an indication of the mass of chlorinated ethenes that was oxidized. Details regarding the post -injection sampling and analysis plan are provided in Section 6.0 of the IRACR. 5.5 SITE RESTORATION Upon completion of the inject work, Shaw restored the site. Due to funding issues, this work was performed in August, 2008. The 200 existing injection points were abandoned in accordance with NC DENR requirements by a NC licensed driller. The injection points were filled with bentonite to seal the points. The injection points in the field and gravel parking areas were filled with bentonite to within one foot of the surface. The top of the casing was removed to about one foot below grade, and the area was either backfilled with top soil and seeded or crushed stone was placed. On the road way area, the injection points were filled with bentonite to within two feet of the surface. The injection points were cut flush with the road surface. The top two feet of the injection point was then filled with a cement grout. The bentonite used was specially coated to allow it to settle to the bottom of the injection point through the ground water, and then begin to expand after several minutes in the water, insuring the complete point was filled. The NC abandonment record was prepared and submitted by the drilling contractor. Shaw removed the roadway barriers and the perimeter access fencing to fully restore the site to the original condition. The site will be inspected quarterly as part of the LUC inspection for the MCB facilities. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 5-4 October 2008 6.0 PROJECT MONITORING Project groundwater monitoring consisted of sampling and analysis of the ten monitoring wells for standard field purge parameters, cVOCs, chloride, and target analyte list (TAL) metals and was performed periodically during the project duration. The following subsections describe the project sampling and analysis of the groundwater and surface water at Site 93. 6.1 GROUNDWATER MONITORING Groundwater samples were collected from the ten monitoring wells around the site for analysis of VOCs, TAL metals, and chloride at various times during the project duration. Monitoring wells MW-05, MW-06, MW-08, MW-09, MW-12, MW-13, MW-14, MW-15 and MW-16 were the selected monitoring wells around the site. They are presented on Figure 6-1. Based on the ground water contours, MW-16 is hydraulically upgradient of the treatment area, and still within the affected area. MW-06 and MW-08 were within the treatment area. Monitoring wells MW-17 and MW-15 are just north and south of the treatment area. Monitoring wells MW-09, MW-13, MW-12, MW-14 and MW-05 are all downgradient of the treatment area. The COCs were TCE, PCE, Cis DCE, Trans DCE, and Vinyl Chloride (VC). The Design Basis Plan (DBP) established the post injection ground water sampling and analysis requirements as quarterly for one year following completion of the injection (semiannually for the first year). Additionally, the DBP stated that monthly samples would be collected for permanganate analysis the first six months following completion of the injection in order to monitor the consumption of permanganate at the site. The post injection monitoring plan was revised once Shaw and the Partnering Team realized the duration necessary to inject the complete volume of reagent. Shaw with the concurrence of the Partnering Team determined that intermediate sampling and analysis was required to determine if the remediation process was working and to evaluate the value of the process prior to the post injection period. The post injection quarterly sampling and analysis was still viable. All sampling and analysis activities were conducted in accordance with the QAPP. Groundwater and surface water samples were analyzed using standard EPA methods where available. 6.1.1 Ground Water Baseline Analysis Shaw collected baseline groundwater samples for analysis prior to beginning injection of the reagent in mid to late October 2006 from the ten monitoring wells. The analytical data is presented on Table 6.1 for the COCs. No other ground water samples from the Baseline Monitoring wells were collected during the Phase 1 work. The next samples from the ten Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 6-1 October 2008 monitoring wells were collected in February 2007 right after the injection system was shut down at the end of Phase 1. The results of the Baseline and February 2007 data are provided in Table 6.1. The data indicated there was sufficient degradation of the COCs, primarily TCE and PCE, from the injection of 92,000 gallons of reagent to continue with the Phase 2 injection and endeavor to place the remaining quantity of reagent. The February 2007 data indicates the ROD ground water criteria within the treatment were not met for all parameters, but most parameters decreased. The concentrations of the COCs in the monitoring wells downgradient of the treatment area were either not affected or increased from October 2006 to February 2007 reagent injection. When analyzing the total COC concentration (addition of concentration of TCE, PCE, Cis DCE, Trans DCE and VC), within the treatment area, MW-06 started at 821 µg/L in October 2006 and was reduced to 719 µg/L by February 2007, a reduction of 12%; MW-08 started at 229 µg/L in October 2006 and was reduced to 113 by February 2007, a reduction of 50%. See data presented in Table 6.2A. 6.1.2 Phase 2 Analysis The Phase 2 injection was performed using a new delivery system which was similar to a localized pump and treat remedial system with the intent of getting more reagent into the sub- surface. The groundwater was removed from the treatment area by a dewatering pumping system; ground water was conveyed to a holding tank; then the groundwater was mixed with the dry powder reagent which treated the groundwater and then it was pumped / gravity fed into the injection points within the treatment area. As noted in Section 4.5, the dewatering points and the injections points were adjacent to each other and about 10 feet away. The dewatering and injection system achieved a closed loop since purple water was observed at various times coming out of the dewatering points during the Phase 2 injections. Shaw collected samples from three of the interior monitoring wells, MW-06, MW-08 and MW- 17, in August 2007, after about 6 weeks of operation, to determine if the system was remediating the groundwater as intended. No other wells were sampled at that time since this was to provide a glimpse of how the process was working and not part of the official monitoring program. There was a decrease in concentration of most COC parameters from the February 2007 sampling event. All of the COC parameters from the 3 monitoring wells decreased in concentration except for VC in MW-08. The COCs in MW -17 were nearing the ROD Criteria; three of the five COCs were below the ROD criteria. See Table 6.1 for the data. Shaw again collected samples from four of the interior monitoring wells, MW-06, MW-08, MW- 17 and MW-13, in September 2007 to monitor the remediation process. Again, most COC Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 6-2 October 2008 parameters continued to decrease with the exception of VC in MW-08, MW-17 and MW-13 increasing. See data present in Table 6.1. The increase in Vinyl Chloride concentration was believed to be a positive sign as it indicated the oxidation was occurring and producing more VC, the proposed end product. Shaw collected ground water samples for analysis from the remaining six monitoring wells, MW-05, MW-09, MW-12, MW-14, MW-15, and MW-16, in October 2007 to have a complete set of the ten monitoring wells over September and October 2007. This was performed to monitor the progress of the remediation / oxidation. The analytical data is present in Table 6.1. The data indicated that the COC concentration in the downgradient wells were either decreasing or staying at roughly the same level. MW-16, the upgradient well, decreased in overall COC concentrations compared to the February 2007 sampling. After Phase 2 injection was stopped in mid December 2007, all ten monitoring wells were sampled in late December 2007. The data from the sampling and analysis from baseline (October 2006) through December 2007 are presented in Table 6.1. The data indicated some reduction in concentrations of COCs, stabilizing in some of the COC parameters and minor increases in other COC concentrations. Many of the COC parameters at the downgradient wells were meeting the ROD Criteria. The data was reviewed by the Partnering Team in February 2008. The Team agreed to collect another set of samples three months after the December 2007 sampling event to detennine if the groundwater remediation continued after the injection stopped. Groundwater samples were collected in mid March 2008 for comparison to the past series of data and evaluation of the remedial process on the groundwater. The COC ground water data is presented in Table 6.1. The data indicates there has been a reduction in the COC parameters, TCE and PCE concentration, within the treatment area and an increase in the VC concentrations, indicating a level of remediation. As the Table 6.1 indicates, many of the COCs at 9 of the ten monitoring wells have met the ROD COC criteria. Graphs of the COC concentrations over time for each parameter at each of the 4 wells around the treatment area are presented on Figure 6-2 through Figure 6-5. When analyzing the total COC concentration (addition of concentration of TCE, PCE, Cis DCE, Trans DCE and VC), within the treatment area, MW-06 started at 821 µg/L in October 2006 and was reduced to 555 µg/L by March 2008, a reduction of 32%; MW-08 started at 229 µg/L in October 2006 and was reduced to 113 by March 2008, a reduction of 51 %. See data presented in Table 6.2B. The BIOCHLOR model presented in the FS was based on a 90% reduction of the Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 --Site 93 6-3 October 2008 concentrations in the treatment area which would allow MNA to take over and meet the NC 2L standard at the discharge to Edwards Creek. Shaw also monitored the TAL metals, Calcium, Chloride, Potassium, and Sodium as requested by NC DENR in the treatment / injection approval letter. This data is presented for each of the ten monitoring wells over time in Table 6.3 to Table 6.12. Background analysis (October 2006) for Calcium, Chloride, Potassium, and Sodium was not performed and not provided in the tables as this was not requested until later in the project. The data indicates there was little variation of the TAL metals over the duration of the injection and spatially from the treatment area. Chloride increased slightly within the treatment area but not as much as the farther away from the treatment area. Calcium and Sodium did not indicate a trend line in the treatment area or within the overall monitored area. Potassium increased in the treatment area and the overall monitored area due to the use of potassium permanganate. This indicates that the reagent was transported to the edges of the monitored area. MNA is a component of this ROD, therefore MNA parameters were analyzed to evaluate the contribution of biodegradation to site restoration. The Natural Attenuation Indicator Parameters (NAIP) are presented in Table 6-13, and compared to the baseline work performed by CH2M Hill. The data indicates the ground water remained in the same condition during the ISCO injection activities except for sulfate and methane. There was an increase in sulfate and a decrease in methane within the treatment area as indicated by the data from Wells MW-06 and MW-08. The increase in sulfate and decrease in methane appear to extend out beyond the treatment area as it was noticed in MW-05, the farthest monitoring well from the treatment area. Most of the other NAIP were non -detect. Shaw performed oxygen —reduction potential (ORP) monitoring periodically at the monitoring wells through the injection phases. The values ranged from -40 to -200 mV within the monitored area which indicates the conditions were favorable for reductive dechlorination. 6.2 SURFACE WATER MONITORING The surface water in the creek was inspected for the presence of pernanganate during the injection process. The surface water was not sampled or tested except for the discharge incident in November 2006. The surface water was inspected daily during the injection periods. On one occasion, the reagent made its way under ground to a point near the un-named tributary to Edwards Creek and discharged to the tributary. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 6-4 October 2008 All sampling and analysis activities were conducted in accordance with the QAPP. Groundwater and surface water samples were analyzed using standard EPA methods where available. When required aqueous KMn04 concentrations were determined using field spectrophotometry. As the ISCO implementation continued, recommendations for changes to the sampling frequency, wells sampled, and parameters for analysis were included in progress reports to the Partnering Team and the public. 6.3 ISCO PERFORMANCE CRITERIA Groundwater VOC concentrations obtained from the monitoring program were evaluated to detennine the effectiveness of the ISCO component of the selected remedy. The overall corrective measure objective was to achieve 21, standards for all COCs across the site after injection of the design quantity of oxidant. Only 60 % of the design quantity of reagent was installed through December 2007 due to site conditions, low site permeability and increased costs. The ISCO component of the selected remedy only targeted the area with total concentrations of chlorinated ethenes in excess of 100 µg/L; COC concentrations continue to remain elevated above 2L standards following the ISCO application. The Partnering Team reviewed the ground water data and the level of effort necessary to inject the remaining designed reagent dosing to achieve the reduction in COC concentrations to 2L standards and determined the addition effort was not cost effective at this time. The Team agreed to continue to perform quarterly monitoring of the10 monitoring wells and review the data at the 5 year review and make recommendations for additional remediation if necessary at that time, or continued monitoring of the site, but in any case LUCs would remain in place. 6.4 HEALTH AND SAFETY Health and safety issues were coordinated by the SHSO prior to field activities and include the designation of exclusion zones, staging areas, and decontamination pads. A SSHP was provided as Appendix A in the Basis of Design document. All personnel working on site reviewed and signed the SSHP, and followed the safety procedures provided. Level D personal protective equipment (PPE) was utilized at the site. The SSHP developed for this activity specifically addressed PPE and circumstances requiring upgrades. There were no health and safety incidents during the performance of this work. 6.5 COMPARISON TO CLEANUP GOALS Shaw placed 60% of the design dose, 224,000 gallons of reagent compared to 398, 000 gallons. The FS had estimated performing the work in 55 days using one DPT rig. Shaw proposed a Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 6-5 October 2008 gravity fed system in the Basis of Design and estimated 90 days in the field to inject the 392,000 gallons. Shaw spent about 100 days in the field injecting 92,000 gallons of reagent due to the low permeability of the sub surface materials. Shaw performed a pump test in the area and modeled the hydraulic characteristics of the sub- surface. Shaw developed an alternative delivery system including a dewatering system and the gravity injection system to improve the injection rate of the reagent. Shaw was able to increase the delivery by 50%, but over the 22 weeks in the field was only able to inject 144,000 gallons of reagent, for a total of 232,000 gallons. The COC concentrations of the ground water in the treatment area decreased by an average of 30% due to the ISCO treatment. The FS had estimated a 90% reduction in COC concentrations was necessary in the treatment area to meet the BIOCHLOR model. The ISCO technology was only able to achieve a 30% reduction in the treatment area using 60% of the reagent and approximately nine months in the field. Many of the COC concentrations in the downgradient wells did meet the ROD Criteria. The Partnering Team believed that the ISCO technology should have done better with the low level of contamination present. The Team decided to monitor the site for the next 2 years and then review the ground water conditions at the five year review period to determine if additional remediation is required. LUCs will remain in place during the monitoring and evaluation period. 6.6 LAND USE CONTROLS Land Use Controls (LUCs) for Site 93 should continue to be implemented to prohibit withdraw and /or future use of water, except for monitoring from the aquifers (surficial and Castle Hayne) within 1,000 feet of the identified groundwater plume. The LUCs would also prohibit intrusive activities within the extent of current groundwater contamination unless specifically approved by both NCDENR and USEPA. The LUCs require filing a Notification of Inactive Hazardous or Waste Disposal per North Carolina General Statute (NCGS) 130A-310.8. 6.7 LESSONS LEARNED During the performance of the project, Shaw gained valuable insight that can apply to other projects: The major limiting factor for this project was the hydraulic permeability of the sub surface materials. The permeability in the vertical and horizontal direction was low hiterim Remedial Action Completion Report Project 120348 Operable Unit No. 16 — Site 93 6-6 October 2008 and impacted the acceptance rate for the reagent. Performing the pump test prior to starting the work would have gotten Shaw to Phase 2 sooner and possibly a different delivery system other than the injection points. 2. The difficulty with the reagent day -lighting / break-out from too much feed from the gravity system would mean that the DPT would have had the same or more problems. The fact that the ground water was so shallow and the interval to be treated was shallow, should have led to a decision not to pressurize the injection system since there was not much space to take the additional fluid caused by injecting the reagent. 3. The Partnering Team believed the ISCO process was not cost effective in reducing the low level contamination at the site and decided to not inject the full design dose of reagent. The additional cost to inject the full dose would have increased the cost of the project probably to $1 M and this cost was too high for the low level of contamination compared to the need for funds at other Camp Lejeune sites. 6.8 RECOMMENDATIONS Groundwater monitoring should continue and Land Use Controls (LUCs) should be maintained until the concentrations of COCs have been reduced to 2L standards across the site and a no - further -action determination is obtained. It is recommended that the Long Term Monitoring (LTM) be performed quarterly post -injection sampling for the designated parameters, and the VOC concentrations be evaluated to determine the effectiveness of the ISCO component of the selected remedy. If concentrations of total chlorinated ethenes remain above 10 µg/L (one order of magnitude below the 100 µg/L targeted concentration), an evaluation will be performed to determine if additional pennanganate injection activities are warranted. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 6-7 October 2008 7.0 SCHEDULE AND COSTS The schedule of the performed remediation is shown in Figure 7-1. The actual cost data is provided in Appendix A and compared to the FS cost estimate. The FS estimated the field effort to be 55 days in the field. Due to the site hydro -geologic conditions, Shaw spent approximately I 1 months in the field performing site preparation and injection to place 60% of the design dose of potassium permanganate for ISCO remediation. Despite the extended duration, the cost for the effort was approximately 15% more than the FS cost estimate due to the reduced usage of reagent and the use of lower cost injection equipment. Interim Remedial Action Completion Report Project 120348 Operable Unit No. 16 -- Site 93 7-1 October 2008 8.0 REFERENCES CH2MHi112005, Final Feasibility Study Operable Unit No. 16 (Site 93), November 2005. CH2MHi11 2006, Final Remedial Design./or Land Use Controls and Monitored Natural Attenuation Operable Unit16 (Site 93), December, 2006 IT Corporation (IT), 2002, Report of Findings, Pilot -Scale Potassium Permanganate Injection, Fire Training Area FT-11 (SWMU 11), Myrtle Beach Air Force Base, Myrtle Beach, South Carolina, October. Shaw Environmental, Inc. (Shaw), 2004a, Final Focused Corrective Measures Study, Building 575 (SWMU 256), Myrtle Beach Air Force Base, Myrtle Beach, South Carolina, April. Shaw Environmental, Inc. (Shaw), 2004b, Operation and Maintenance Plan, Interim Corrective Measure, Groundwater Recovery System, Building 575 (SWMU 256), Myrtle Beach Air Force Base, Myrtle Beach, South Carolina, August. Shaw Environmental, Inc. (Shaw), 2003, Myrtle Beach Air Force Base Quality Assurance Program Plan, Myrtle Beach Air Force Base, Myrtle Beach, South Carolina, prepared for U.S. Army Corps of Engineers, Omaha District, October. Simpson, M. J., T. P. Clement, and F. E. Yeomans, 2003,"Analytical Model for Computing Residence Times Near a Pumping Well," Ground Water, Vol. 41, No. 3, pp. 351-354. Yan, Ye and F. W. Scwartz, 2000b, Oxidative Degradation of Chlorinated Ethelenes by Permanganate, Ohio State Progress Report. Completion Report Project 120348 Operable Unit No. 16 — Site 93 8-1 March 2008 TABLES TABLE 3.1 CHRONOLOGY OF EVENTS Proposed Remedial Action Plan Submitted Record of Decision Signed Basis of Remedial Design Submitted / Approved Install Injection Points Collect Baseline Samples Set-up Mixing / Injection Operation Begin Injection of Permanganate —Phase I Stop Permanganate Injection Phase 1 Collect First Round of Remediation Samples Perform Pump Test Evaluate Permanganate Delivery System Prepare Technical Memo on Modified Permanganate Delivery System Received NC DENR Approval of Delivery Method Begin Phase 2 Permanganate Injection Collect Intermediate Remediation Samples Collect Intermediate Remediation Samples Collect Intermediate Remediation Samples Finish Phase 2 Permanganate Injection Collect Intermediate Remediation Samples Collect Intermediate Remediation Samples Evaluate Data Site Restoration February 16, 2006 May 2006 October 2006 October 17, 2006 October 11115, 2007 October 21, 2006 October 30, 2006 February 12, 2007 February 15, 2007 April 2007 May 2007 June 2007 June 19, 2007 June 20, 2007 August 9, 2007 September 27, 2007 October 17, 2007 December 17, 2007 December 27, 2007 March 17, 2008 April 2008 August 2008 TABLE 6.1 Groundwater Analytical Data (Volatile Organic Compounds) Site 93, Camp LeJeune Marine Corps Base, North Carolina 10/i5/06 02/01/07 10/07/07 12127107 3/18/2008 ROD Criteria Current NC 2L TCE 163 138 78.7 91.5 86.8 2.8 2.8 Tetrachloroethylene 94.4 65.6 15.9 22.1 14.7 0.7 0.17 MW-06 Cis DCE 409 373 383 390 328 70 Trans DCE 150 138 116 120 115 70 100 VC 4.6 4.5 ND 5.9 9.5 0.015 0.015 TCE 38.3 21.2 11 3 2.8 2.8 2.8 Tetrachloroethylene 82.9 20 5.5 1.1 1.8 0.7 0.17 MW-08 Cis DCE 77.2 52.3 80.6 89.5 70.9 70 Trans DCE 26.2 17.9 9.2 6.7 4.4 70 100 VC 3.9 2.1 18.8 33.4 32 0.015 0.015 TCE 3.4 3.5 1.9 3.3 ND 2.8 2.8 Tetrachloroethylene 2.1 3.5 NO 0.67 ND 0.7 0.17 MW-17 Cis DCE 72 67.3 96.5 193 45.6 70 Trans DCE 22.1 11.5 27.7 49.9 8.8 70 100 VC 11.7 18.5 42.4 47.1 14.9 0.015 0.015 TCE 3.5 3.2 2.8 0.78 1.1 2.8 2.8 Tetrachloroethylene NO ND ND ND NO 0.7 0.17 MW-13 Cis DCE 81.8 177 111 57.2 82.8 70 Trans DCE 24.2 69.5 28 16 33.6 70 100 VC 6.9 16.6 66.5 95.7 104 0.015 0.015 TCE 28.1 29.2 31.7 34.3 34.8 2.8 2.8 Tetrachloroethylene 0.65 0.63 0.63 0.77 0.89 0.7 0.17 MW-05 Cis DCE 51.6 51.8 58.5 60.8 60 70 Trans DCE 21.6 23.5 25.7 26.5 31.6 70 100 VC 1.1 1.4 1.2 1.9 2 0.015 0.015 TCE NO ND NO NO NO 2.8 2.8 Tetrachloroethylene NO ND NO NO ND 0.7 0.17 MW-12 Cis DCE 7.2 6.6 32.8 23.1 28.5 70 Trans DCE NO 0.54 4.1 3.1 4.7 70 100 VC ND 1.7 3.4 3.6 4.6 0.015 0.015 TCE 11.9 13.7 3.1 3.4 2.5 2.8 2.8 Tetrachloroethylene ND ND NO NO ND 0.7 0.17 MW-14 Cis DCE 51.6 92.2 23.8 46.1 36.9 70 Trans DCE 9 18.4 2.6 8.6 6.9 70 100 VC 2.4 10.6 16.9 70.4 73.2 0.015 0.015 TCE NO 0.99 NO ND 0.68 2.8 2.8 Tetrachloroethylene ND 1.1 NO ND NO 0.7 0.17 MW-15 Cis DCE 3.1 3.6 3.8 3 3.1 70 Trans DCE ND ND ND NO 0.29 70 100 VC ND ND NO NO ND 0.015 0.015 TCE 17.5 49.7 38.9 36.8 30.7 2.8 2.8 Tetrachloroethylene 9.3 17.1 17.2 12.8 11.8 0.7 0.17 MW-16 Cis DCE 56 148 93.6 69.6 68.6 70 Trans DCE 15.6 56.6 29.2 24.3 25.7 70 100 VC 0.9 1.8 1.6 1.9 2.1 0.015 0.015 TCE 15.9 1.5 0.44 4.9 2.8 2.8 Tetrachloroethylene NO ND NO NO 0.7 0.17 MW-09 Cis DCE 94.6 21.3 0.42 25.9 70 Trans DCE 28.9 6.7 0.33 9.3 70 100 VC 10.9 2.5 ND 3 0.015 0.015 Sampling event reflected as 10/15/06 is the site baseline for this project. Sampling event reflected as 10/07/07 had four wells (MW-06, MW-08, MW-17, and MW-13) sampled on 09/07/07. Highlighted data indicates compliance with ROD criteria. Q) C O L U Co a> U U 'O O 3 z O aj Q N E co O M U N Q N °' co U L W CD J m � � ~ � N _U 3 (6 N C —J Q 0 cu co -a rS o E U CO 0 0 a O 0 0 o ° ° W V M M co N O � N n M M 6) M V GO O N M V W GO M W LO GV O M O �- O N M'o� N Q O M'oM=VNNLO=NMMM MMZ �(O M V 6) O CO M O N N O 7 N Q W N O O d0' V' M W ti N M M N N M z coN co N N N N a `o U w o U w o V w o` w U w M❑ � w m w m w UM❑� h fa)Uh> FhUIL> hFUF> FU- FT-Uh> CO W I� M Co cn C O U N �U O 70 O Z E co Q y O CD U N N 2)U W C J m m F- N U_ _ J � J Q Q m �U 3 a co O C9 CO 0 co 0 W M O 0 R O 0 0 0 U( O Il M M L6 Cl) O) O O co Ln µ Ln co N N O Ln M d N N co W N � CO I- W` M W W� V N 0 o co m 6) 0 oO q 0 'COO "' M c- 6 N Z Z V co V c- Z co M � M dt 6) O (p M 6) N N O V `- N h L6 CO N 0)W V d' M W r N M M N N M Z coN 6 C C C G o W o W `6 o W `o o W `6 o Lli U U U U U� cciUO W G cci W@ cLiU0 W C cLiU� W i-rUri rf Ur% f-rUf-> f-f-Uf-i C6 N f� M TABLE 6.3 MW-06 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 8/9/2007 9/27/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Result Chloride EPA 300/SW846 9056 30100 30900 40600 33000 31800 Aluminum SW846 6010E 482 128 516 170 141 Antimony SW846 6010B ND ND ND ND ND Arsenic SW846 6010B ND ND ND ND ND ND Barium SW846 601 OB 48.1 109 82.4 197 70.6 59.9 Beryllium SW8466010B 1 ND ND ND ND Cadmium SW8466010B ND ND ND ND ND ND Calcium SW8466010B 81900 81900 210000 79700 72100 Chromium SW8466010B 3 0.89 ND 4.4 1.5 ND Cobalt SW8466010B ND ND ND ND ND Copper SW8466010B ND ND ND ND ND Iron SW8466010B 20600 13300 18800 10900 10000 Lead SW846 6010E 3.8 ND ND ND ND ND Magnesium SW846 6010B 10500 9330 183001 9340 8150 Manganese SW846 6010E 3271 836 2360 6680 6750 Mercury SW846 7470A ND ND ND ND ND ND Nickel SW8466010B ND ND 1.8 1.1 ND Potassium SW846 6010B 38400 180000 923000 237000 189000 Selenium SW8466010B ND ND ND ND ND ND Silver SW8466010B ND ND ND ND ND 0.83 Sodium SW8466010B 45900 51200 78300 50500 46300 Thallium SW846 ND ND 6.5 ND 7.2 Vanadium SW846 6010B 3.1 1.4 ND 2.3 ND Zinc SW8466010B 8.7 ND 15.6 16.2 13 All data presented in ug/L units. TABLE 6.4 MW-08 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 8/9/2007 9/27/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Result Chloride EPA 300/SW846 9056 21300 19100 15800 18400 16600 Aluminum SW8466010B 358 120 117 ND ND Antimony SW8466010B ND ND ND ND ND Arsenic SW8466010B ND ND ND ND ND ND Barium SW8466010B 97.9 290 118 97.1 101 51.1 Beryllium SW846 6010B 1.1 ND ND ND ND Cadmium SW8466010B ND ND ND ND ND ND Calcium SW8466010B 84000 69100 59400 41000 46700 Chromium SW8466010B 4.5 9.9 2.6 ND 2 ND Cobalt SW8466010B ND ND ND ND ND Copper SW8466010B ND ND ND 2 ND Iron SW8466010B 5770 1660 1530 2390 1000 Lead SW8466010B ND ND ND ND 4.2 3.1 Magnesium SW846 6010E 6940 8000 7810 5600 5960 Manganese SW846 60106 1 7750 151001 136001 12600 9820 Mercury SW846 7470A 0.15 ND ND ND ND ND Nickel SW846 6010B ND ND 1.1 ND ND Potassium SW846 6010B 425000 380000 352000 287000 231000 Selenium SW846 6010B ND ND 6.4 ND ND ND Silver SW846 6010E ND ND ND ND ND ND Sodium SW846 6010E 31300 25500 31900 19600 20106 Thallium SW8466010B ND ND 14.4 ND 9.7 Vanadium SW8466010B 1.51 ND ND 1A ND Zinc SW8466010B 3.6 ND 12 NDI 7.3 All data presented in ug/L units. TABLE 6.5 MW-17 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 8/9/2007 9/27/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Result Chloride EPA 300/SW846 9056 15700 13000 12200 20900 11400 Aluminum SW846 6010B 165 ND ND ND 146 Antimony SW846 6010B ND ND ND ND ND Arsenic SW846 6010E ND ND ND ND ND ND Barium SW846 6010B 85.5 78.8 51.7 56.8 68.1 55.2 Beryllium SW846 6010B ND ND ND ND ND Cadmium SW846 60106 ND ND ND ND ND ND Calcium SW8466010B 109000 101000 106000 105000 118000 Chromium SW846 6010B 1.9 ND ND ND 1.2 ND Cobalt SW846 6010B ND ND ND ND ND Copper SW846 6010B ND ND 1.4 ND ND Iron SW846 6010B 9870 2390 2900 7360 5050 Lead SW8466010B ND ND ND 3.4 ND 2.2 Magnesium SW84660106 26401 2500 26301 2280 2550 Manganese SW8466010B 54.9 34.9 34.4 40.3 45.9 Mercury SW8467470A ND ND ND ND ND ND Nickel SW8466010B ND ND ND ND ND Potassium SW8466010B 1180 2120 3230 1290 3330 Selenium SW846 6010B ND ND ND ND ND 4.1 Silver SW846 6010B ND ND 1.3 ND ND ND Sodium SW846 6010B 11900 18600 19200 14900 15400 Thallium SW846 6010B ND ND ND ND ND Vanadium SW846 6010B 2 ND ND 1.3 1.3 Zinc SW846 60106 103 10 21.7 11.6 43.9 All data presented in ug/L units. TABLE 6.6 MW-13 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW8469056 23900 17300 21400 21000 Aluminum SW8466010B 93.1 ND ND ND Antimony SW8466010B ND ND ND ND Arsenic SW846 6010B ND ND ND ND ND Barium SW846 6010B 86.3 97 176 110 148 Beryllium SW846 6010B ND ND ND ND Cadmium SW846 6010B ND ND ND ND ND Calcium SW846 6010E 111000 168000 112000 133000 Chromium SW846 6010B 1.8 ND ND ND ND Cobalt SW8466010B ND ND ND ND Copper SW8466010B ND ND ND ND Iron SW8466010B 6080 3250 2170 2550 Lead SW8466010B ND ND 3.2 2.9 ND Magnesium SW8466010B 2440 3840 3100 3220 Manganese SW8466010B 39 67.61 51.5 52.4 Mercury SW8467470A ND ND ND ND ND Nickel SW8466010B ND ND ND ND Potassium SW846 6010B 1080 146000 40900 54300 Selenium SW8466010B ND ND - ND ND ND Silver SW8466010B ND ND ND ND ND Sodium SW8466010B 18500 24100 39500 25800 Thallium SW8466010B ND ND ND ND Vanadium SW8466010B 1.3 ND ND ND ZincI SW8466010B 1 1 13.11 NDI ND ND All data presented in ug/L units. TABLE 6.7 MW-05 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW8469056 14900 13900 15400 15000 Aluminum SW846 6010B 45.2 138 156 206 Antimony SW846 6010B ND ND ND ND Arsenic SW8466010B ND ND ND ND ND Barium SW84660106 81.2 37.9 51.6 45.7 43.5 Beryllium SW8466010B ND ND ND ND Cadmium SW8466010B NDI ND ND ND ND Calcium SW846 6010B 14900 20100 18400 17400 Chromium SW846 6010E 1.5 ND ND ND ND Cobalt SW846 6010E ND ND ND ND Copper SW846 6010B ND ND ND ND Iron SW846 6010E 3580 2050 3090 8050 Lead SW8466010B ND ND ND 2.8 2.8 Magnesium SW846 6010B 1290 1710 1410 1270 Manganese SW8466010B 30 24.11 42 58.3 Mercury SW8467470A ND ND ND ND ND Nickel SW8466010B ND ND 1 ND Potassium SW8466010B 814 1330 1030 3150 Selenium SW8466010B ND ND ND ND ND Silver SW8466010B ND ND ND ND ND Sodium SW846 6010B 10800 11500 11000 14000 Thallium SW846 6010E ND ND ND ND Vanadium SW846 6010B ND ND ND ND Zinc SW846 6010B ND ND 7.2 ND All data presented in ug/L units. TABLE 6.8 MW-12 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW846 9056 12800 13100 13600 13400 Aluminum SW8466010B 801 3610 1750 461 Antimony SW8466010B ND ND ND ND Arsenic SW846 6010B ND ND ND ND ND Barium SW846 6010B 82.4 37.3 58.5 36.3 35.5 Beryllium SW846 6010B ND ND ND ND Cadmium SW8466010B ND ND ND ND ND Calcium SW846 6010E 83600 103000 87400 92800 Chromium SW846 6010B 1.6 1.6 11.1 5.4 1.2 Cobalt SW8466010B ND 2.6 1.5 ND Copper SW8466010B ND 38.1 2.3 2.4 Iron SW8466010B 4810 15800 8860 5910 Lead SW8466010B 3.6 ND 5 ND 3.8 Magnesium SW84660106 1790 2710 2030 1890 Manganese SW84660106 1 43.1 94.91 64.4 45 Mercury SW8467470A NDI ND NDl ND ND Nickel SW8466010B ND 21.2 2.7 1.7 Potassium SW8466010B 864 2530 1470 3340 Selenium SW8466010B ND ND ND ND ND Silver SW8466010B ND ND ND ND ND Sodium SW846 6010B 5590 5980 5770 7600 ham SW8466010B ND ND ND ND Valliunadium SW846 6010E 2.5 %2 5.2 1.4 Zinc I SW846 6010E 8.51 183 15.5 12.7 All data presented in ug/L units. TABLE 6.9 MW-14 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW846 9056 14100 12600 15400 15200 Aluminum SW846 6010B 56.2 ND ND 94.3 Antimony SW8466010B ND ND ND ND Arsenic SW8466010B ND ND ND ND ND Barium SW8466010B 89.1 78.4 62.7 73.1 88.2 Beryllium SW84660108 ND ND ND ND Cadmium SW8466010B ND ND ND ND ND Calcium SW8466010B 97500 120000 133000 162000 Chromium SW8466010B 1.7 ND ND ND ND Cobalt SW8466010B ND ND ND ND Copper SW8466010B ND 4.4 ND ND Iron SW8466010B 12300 3770 4060 6510 Lead SW8466010B 3.5 ND ND 2.9 2.3 Magnesium SW84660106 1 2070 2610 3070 3720 Manganese SW8466010B 49 53.9 61.4 70 Mercury SW8467470A 0.13 ND ND ND ND Nickel SW8466010B ND ND ND ND Potassium SW8466010B 1010 2050 1700 3790 Selenium SW8466010B ND ND ND ND ND Silver SW8466010B ND ND ND ND ND Sodium SW8466010B 13200 13300 15000 18100 Thallium SW8466010B ND ND ND ND Vanadium SW846 6010B 1.8 ND ND ND Zinc SW846 6010E 37.8 48.3 17.6 181 All data presented in ug/L units. TABLE 6.10 MW-15 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/2712006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW8469056 11000 11200 12000 11900 Aluminum SW8466010B 36.4 ND ND ND Antimony SW8466010B ND ND ND ND Arsenic SW8466010B ND ND ND ND ND Barium SW8466010B 84.2 37.9 25.4 25.9 24.4 Beryllium SW8466010B ND ND ND ND Cadmium SW8466010B ND ND ND ND ND Calcium SW8466010B 83500 85300 81200 91800 Chromium SW8466010B 1.8 ND 1 ND ND Cobalt SW846 6010B ND ND ND ND Copper SW846 6010B ND ND ND ND Iron SW846 6010E 8960 2550 3690 2890 Lead SW846 6010E 3.6 ND ND ND ND Magnesium SW846 6010B 1700 1840 1660 1840 Manganese SW8466010B 39.6 36.91 49.6 39.8 Mercury SW8467470A NDI ND NDI ND ND Nickel SW8466010B ND ND ND ND Potassium SW8466010B 845 1320 1070 3230 Selenium SW8466010B ND ND ND ND ND Silver SW8466010B ND ND ND ND 0.95 Sodium SW8466010B 4990 5760 5650 8020 Thallium SW8466010B ND ND ND ND Vanadium SW8466010B 1.1 ND ND ND Zinc SW8466010B 91.4 8.8 12.6 18.8 All data presented in ug/L units. TABLE 6.11 MW-16 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW846 9056 22600 13400 12800 14800 Aluminum SW8466010B 2990 134 405 376 Antimony SW8466010B ND ND ND ND Arsenic SW846 6010E ND ND ND ND ND Barium SW8466010B 95.8 70.8 51.4 58.4 54.4 Beryllium SW8466010B ND No, ND ND Cadmium SW8466010B NDI ND ND ND ND Calcium SW8466010B 138000 101000 95000 108000 Chromium SW8466010B 10.6 6.7 7.3 3.1 0.94 Cobalt SW8466010B 1.1 ND ND ND Copper SW8466010B ND ND ND ND Iron SW846 6010B 22300 7210 12200 11206 Lead SW846 6010E 7.3 ND ND ND 2.9 Magnesium SW846 6010E 9140 4800 3480 5210 Manganese SW8466010B 141 69.91 56.8 69 Mercury SW8467470A NDI ND ND ND ND Nickel SW8466010B 5.3 6 5 12.6 Potassium SW8466010B 2400 2310 1580 3860 Selenium SW8466010B ND ND ND ND ND Silver SW8466010B ND ND 0.81 ND 0.84 Sodium SW8466010B 42800 19300 14400 21800 Thallium SW8466010B ND ND ND ND Vanadium SW8466010B 7.8 ND 2.2 ND Zinc SW8466010B 70.3 19.3 27 8.8 All data presented in ug/L units. TABLE 6.12 MW-09 Groundwater Analytical Data Site 93, Camp LeJeune Marine Corps Base, North Carolina Sampling Date: 10/27/2006 2/15/2007 10/17/2007 12/27/2007 3/18/2008 Parameter Method Result Result Result Result Result Chloride EPA 300/SW846 9056 10400 12400 7800 12700 Aluminum SW846 6010B 1210 340 191 1240 Antimony SW8466010B ND ND ND ND Arsenic SW8466010B 6.2 ND ND ND ND Barium SW8466010B 157 42.6 22.3 5.5 24.1 Beryllium SW84660106 ND ND ND ND Cadmium SW846 6010B ND ND ND ND ND Calcium SW846 6010B 60700 38000 22200 43000 Chromium SW8466010B 32.6 2.3 38 2.1 22.8 Cobalt SW8466010B ND ND ND 1.1 Copper SW8466010B 1.7 ND ND 6.3 Iron SW846 6010B 2060 5950 152 4640 Lead SW846 6010B 20.9 2.1 ND 3.3 11 Magnesium SW846 6010B 1740 12801 562 1160 Manganese SW846 6010B 59.5 91.2 43.9 188 Mercury SW8467470A NDI ND ND ND ND Nickel SW846 6010E 1.7 ND 1 7 Potassium SW846 6010B 906 1810 1990 3480 Selenium SW846 6010B ND ND ND ND ND Silver SW846 6010B ND ND 3.6 0.82 3.4 Sodium SW846 6010B 7610 8980 1670 10700 Thallium SW846 6010E ND ND ND ND Vanadium SW846 6010E 2.6 3 5 9 Zinc SW846 6010B 53.3 25.4 12.7 156 All data presented in ug/L units. v N N L � ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z ❑ Z W w E M N M V N m N a d N o 0 0 N ❑ M o 0 0 0 0 0 Z Z Z Z Z Z Z Z Z Z z N N J ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ O O ❑ ❑ z z z z z z z z z z z z z 2 E o v R❑❑ o❑❑❑❑ o❑ o o o o z z z z z z z z z z z z z 1c) z z E ❑ M c M v M v M v M M co m m m v o 0 0 0 0 0 0 0 0 L 0 0 0 0 E 2 Q 2 Q 2 Q 2 Q 2 2i 2i��� m fn O 0 3= 3= 3= 3= 3 3 3 3 3 3 U n Y Y L L L L L L L L L L Y H E m N ❑ 115 j l0 N3r3VN 113 0 3 3 � 3