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SDMS Document 115554 DRAFT DRAFT REMEDIAL INVESTIGATION WORK PLAN ADDENDUM - PHASE l i i VIRGIN ISLAND CHEMICAL SITE ST. CROIX, U.S. VIRGIN ISLANDS Prepared for Island Chemical Coinpany HLA. Project No. 35241.5 John S. Virgie, P.G. Senior Geologist Edward A. Nemecek, R.G., CPG Principal Hydrogeologist Regional Geosciences Manager January 20, 1997 ^__^_____ Harding Lawson Associates s a a = ' " g 14 Washington Road, Building 7 o n o 1 R 9 S a s -r 1 1 Princeton Junction, New Jersey 08550 3 0 ^ l o ^ (609)936-0700 CONTENTS 1.0 BACKGROUND 1 1.1 Introduction 1 1.2 Site Description 1 1.2.1 Site Location 1 1.2.2 Site Structures 1 1.2.3 Site Setting 2 1.3 Previous Activities and Data Needs 2 1.4 Objectives 3 2.0 WORK PLAN APPROACH 4 3,0 SUPPLEMENTAL REMEDIAL INVESTIGATION TASKS 8 3.1 Field Sampling Program 6 3.1.1 Soil and Groimdwater Investigation at AST Area 6 3.1.2 Site-Wide Groimdwater Quality SampUng 9 3.1.3 Onsite Groundwater Elevation Monitoring 9 3.1.4 Evaluate Groundwater Flow Direction In Deep Water-Bearing Zone 9 3.1.5 Storm Drain and River Gut Sediment Sampling 10 3.2 Data Validation 11 3.3 Data Evaluation 11 3.4 Update/Track ARARs 11 3.5 Project Meetings and Reporting 12 3.5.1 Meetings with EPA 12 3!5.2 Monthly Progress Reports 12 3.6 Management of Investigation-Derived Waste 12 4.0 ANTiaPATED SCHEDULE 13 FIGURES 1-1 Site Location Map 1-2 Site Map 1-3 Regional Geologic Map 2-1 Flow Chart 3-1 Proposed Samphng Locations 3-2 Double-Cased Monitoring Well Construction Diagram 3-3 Approximate Location of Offsite Production Wells 3-4 Proposed Locations of Onsite and River Gut Sediment Sampling APPENDIXES AB Containers, Preservation, Packaging, and Shipping Requirements AD Field Sampling Plan CD Quality Assurance Project Plan DISTRIBUTION to o to M « ^ O G:\WORK\3524l\rdadd3ml.DOC Harding Lawson Associates DRAFT 1.0 BACKGROUND 1.1 introduction Harding Lawson Associates (HLA) has prepared this Remedial Investigation Work Plem Addendum on behalf of Island Chemical Corporation (ICC) as part of the Remedial Investigation (RI) of the Virgin Island Chemical site (site) located in SL Croix, U.S. Virgin Islands. This RI Work Plan Addendum is intended to address issues discussed and agreed to during the meeting on October 17, 1996, with the U.S. Environmental Protection Agency, Region II (EPA) and comments presented tn EPA's letter dated December 23, 1996. The work described in this document will be performed in accordance with the project Sampling and Anedysis Plem (SAP), Hecdth emd Safety Plem (HASP), and Qucdity Assurance Project Plan (QAPP) provided with the Remedioi Investigation Work Plan (Work Plan), dated March 17, 1994 and revised August 5, 1994 (HLA, 1994). Addenda to these docmnents are included as Appendixes 1.2 Site Description 1.2.1 Site Location The site occupies approximately 3 acres in south central St. Croix, U.S. Virgin Islands (Figure 1-1). The site is located on Melvin Evans Highway (Route 66), approximately 1,500 feet north of the Alexander Hamilton Airport. The property is located on Plot 13Q of Estate Bethlehem Middle Works at 17''42'35" north latitude, 64°47'26" west longitude. The site is bordered to the northeast and southeast by an intermittent stream identified as the River Gut. It is bordered to the west by an undeveloped lot and to the southwest by Route 66. A concrete batch plant and two automobile repair shops are located to the east of the site, across the River Gut. An asphalt paving company is located north-northwest of the site across the River Gut. 1.2.2 Site Structures The facility is currently abandoned. The current layout of the facility is shown in Figure 1-2. Major onsite structures include the following: Laboratory and Warehoxise Building Maintenance Building Above-Grovmd Storage Tank (AST) Farm Concrete Pads adjacent to AST Farm (former AST locations) Loading Dock Concrete Storage Pad Centrifuge and Dryer Building Reactor Process Area Former Process Pit (filled during previous work at this site) Generator Building Pump Bmlding ^ H 250,000-Gallon Fire Water AST to G:\W0RK\3S 24 i\nladd3mI.DOC Harding Lawson Associates DRAFT 1.2.3 Site Setting The site is located in a valley. Surface elevations at the site range from approximately 30 to 40 feet above mean sea level (MSL). Land to the southwest (approximately 200 feet) and to the east (approximately 1,000 feet) of the site slopes steeply upward to roughly 150 to 200 feet above MSL. The ground surface slopes gently across the site from southwest to northeast. Ground surface just beyond the northern and eastern fence Unes slopes steeply downward approximately 12 to 15 feet into the River GuL An earthen berm, approximately 4 feet high, partially separates the AST farm in the western part of the faciUty from the remainder of the site. On the western side of the berm, runoff drains from southwest to northeast Surface drainage on the eastern portion of the site is controlled by the buildings, concrete paved areas, and two storm drains that chaimel nmoff along the southeastern site boundary (Figure 1-2). Flow in the River Gut is intermittent and generally occurs only during the rainy season, between September and December. The Caribbean Sea is located approximately 4,500 feet south of the site. Based on previous investigations, shallow soils beneath the site consist of alluvium. The geology and hydrogeology of St. Croix were discussed in more detail in the Work Plan and in the Draft Data Summary Report (DSR) , dated August 15, 1995 (HLA, 1995). Figure 1-3 presents a generalized geologic map of the island. 1.3 Previous Activities and Data Needs Between September 1984 and March 1986, Enviro-Science, Inc. (ESI) performed a series of investigations of selected portions of the site. In September 1985 and March 1986, EPA collected several samples from the site. Between March 1989 and April 1991, EPA performed a preliminary assessment and drum removal. In February 1991, NUS Corporation (NUS) collected groundwater, soil and sediment samples as part of a Preliminary Assessment/Site Investigation, performed on behalf of EPA. Data generated during these activities were sxmimarized in the Remedial Investigation Work Plan (HLA, 1994). From October 1994 to August 1995, HLA implemented the EPA-approved Remedial Investigation Work Plan. Results of work performed to date were summarized in the DSR (HLA, 1995). The key findings of that investigation were: • Volatile organic compoimds (VOCs) were detected in soils and shallow groimdwater samples collected at MW-1 in the vicinity of Tanks 8 and 9 in the above-ground storage tank (AST) area. • The two primary constituents of concern identified in previous investigations, p)nidine and chloroform, were not detected in any soil or groundwater samples collected during HLA's 1995 investigation. • The visual reconnaissance performed after site clearing revealed no additional potential source areas. Following EPA's review of the DSR, HLA prepared a proposal letter (April 12, 1996) and Phase II RI Work Plan (May 15, 1996) to address the following data needs requested by EPA: • Obtain additional information in shallow groimdwater flow direction over time. • Extent of impacted soil and groundwater identified in the vicinity of Tanks 8 and 9 tn the AST area. • Groundwater quality near the center of the site (Former Process Pit Area). G:\WORK\3524l\rdadd3ml.DOC Harding Lawson Associates 3 02192 B DRAFT From May through August 1996, HLA implemented the EPA-approved Phase n RI Work Plan. Results of the work performed during the completion of Phase n activities were summarized in the Draft Supplemental Data Summary Report, dated September 13, 1996 (HLA, 1996). The key findings of that investigation were: • The lateral and vertical extent of VOCs in soils at the AST area were defined to the north, east, and south^ of the identified source area, but not to the west (offsite). The extent of VOCs in groundwater was not defined in a downgradient or western direction. • Chloroform was detected above the Federal Maximum Contaminant Level (MCL) in shallow groundwater at the former process pit area (Monitoring Well MW-2). • Based on several months of continuous groundwater level monitoring, a shallow groundwater divide trending north-south is interpreted to exist at the site. The groundwater flow direction across the majority of the site west of the divide is to the west and northwest, and the flow direction tn the easternmost portion of the site east of the divide to the east and northeast On October 17, 1996, EPA met with HLA to discuss the findings of the Supplemental Data Summary Report. EPA suggested that several data needs still remained and that they be addressed through supplemental investigative activities. Objectives are discussed below. Activities are identified in Section 2.0. 1.4 Objectives The objectives of this phase (Phase HI) of the RI are to address the foUowing data needs identified during the October 17, 1996, meeting wdth EPA. • Further evaluate the lateral and vertical extent (onsite and offsite) of toluene, ethylbenzene, and xylene (TEX) previously detected in soils and groundwater related to the smaU area near Tanks 8 and 9 in the AST area. • Estimate hydrogeologic properties (specifically hydraulic conductivity) of the shaUow and deep water-bearing zones onsite. • Evaluate the flow direction in the deeper portion of the water-bearing zone. • Perform groundwater sampling (including production wells Pl and P2) to evaluate the extent of VOCs, including chloroform, tn groundwater. • Evaluate Target Analyte List (TAL) metals concentrations onsite and in River Gut • Preliminarily evaluate the appUcabiUty of soil vapor extraction as a possible remedial altemative for soil tn the AST area. • Obtain available water quality data from Fairplains supply weUs from the Virgin Island Water and Power Authority The tasks described in Sections 2.0 and 3.0 of this RI Work Plan Addendum are designed to achieve these objectives. Following completion of these tasks, HLA wiU evaluate the findings of the RI and present results. o At tha meeting ou October 17,1996, EPA's coutractor, CDM Fedetal Programs, disputed that the extent of VOCs had been M defmed to tha south of the presumed source aiea, since VOCs had been detected in southernmost boring SBB2. HLA noted that continuous field screening of soils from 0 to 18 feet at SBB2 did not detect VOCs. The presence of VOCs in soil samples fiom 20 to 22 feet and 22 to 24 feet at SBB2 is attributed to capillary effects by underlying, VOC-containing groundwater. G:\WORK\3S24i\rdadd3ml.OOC Harding Lawson Associates DRAFT 2.0 WORK PLAN APPROACH Figure 2-1 presents a flow chart which summarizes the proposed tasks to be implemented to satisfy the data needs identified in Section 1.4. The tasks to be completed are as foUows: 1. AST Area Investigation: Soils • InstaU soil borings offsite (west) of previous boring SBB17/MW-6 and, at the request of EPA, instaU four additional soU borings within the general AST area to evaluate the possible presence of additional source areas. Data from previous soU boring SBEl, which was instaUed near the former concrete pad, wiU also be used in this evaluation. • PreUminarily evaluate the appUcabiUty of soil vapor extraction (SVE) as a remedial altemative by collecting soil samples for analysis of grain size, moisture, total organic carbon, porosity, biological numeration, and nutrients. Groundwater • Evaluate the lateral extent of TEX in shaUow groimdwater offsite to the west of the AST area by collecting groundwater samples from temporary weUs to be installed at multiple locations, and by instaUing an offsite shallow monitoring well near the dovvmgradient extent of the plume; access restrictions may Umit the well location. • Evaluate the vertical extent of TEX in groundwater beneath the AST area by instalUng a double-cased monitoring weU whose depth will be based on TEX concentrations detected in depth-discrete groundwater Hydropunch® samples collected from a borehole next to MW-6. • Preliminary estimate of the hydrogeologic properties of the shallow and deep water-bearing zones by performing slug tests and by monitoring water level responses during development of the newly installed monitoring wells. 2. Evaluation of Groundwater Quality: • Evaluate site-wide distribution of VOCs in groundwater by coUecting groundwater samples from onsite and offsite weUs including the newly installed shaUow weU, newly installed deep weU in AST area, shaUow monitoring wells, and deep former production weUs using low-flow purging techniques. 3. Evaluation of Deep Zone Groundwater Flow Direction: • UtiUze a downhole television survey to evaluate the screen intervals and the integrity of onsite former production wells Pl and P2. • Measure the water level in the new deep weU in the AST area and incorporate this information with water levels coUected from existing onsite production weUs to evaluate onsite flow direction in the deep portion of the water-bearing zone. • Obtain access, survey physical location and elevation, and measure water levels tn aU weUs to which access is granted within a 0.25- mUe radius of the site. Incorporate water level elevation data from offsite and onsite deep weUs to further evaluate regional flow direction in to the deep water-bearing zone; access restrictions may Umit the number of weUs to be monitored. o to to G:\WORK\3524i\rdadd3ml.DOC Harding Lawson Associates DRAFT 4. Onsite Storm Drain and River Gut Sediment Sampling: • Secure access to coUect sediment samples from offsite locations in River Gut CoUect twenty sediment samples wdthin the onsite drainage system and in the section of the River Gut along the site boundary to evaluate TAL metals concentrations. SampUng in River Gut wiU be conducted upstream, across from, and downstream of the site. These data wtU be evaluated with data from previous sampling activities; access restrictions may Umit the number of samples to be coUected. 5. Data Validation • Confirmation level laboratory data generated for investigative samples wiU be vaUdated as discussed in the Work Plan. 6. Data Evaluation and Reporting: • Interpret, evaluate and summarize the results of the proposed supplemental investigation, incorporate the jesults with previous investigations, and prepare a report for submittal to the EPA. 7. Meetings, Progress Reports, and Presentations to EPA 8. Management and Disposal of Investigation-Derived Wastes G:\WORK\3524i\nladd3ml.DOC Harding Lawson Associates "307195 DRAFT 3.0 SUPPLEMENTAL REMEDIAL INVESTIGATION TASKS The tasks to be completed during this phase of the RI are explained in more detaU below. Specifics of weU locations, weUs to be sampled, soU sample locations, analytical parameters, and other activities may need to be modified based on possible legal access restrictions, physical restrictions and on the findings of various phases of each tasks. EPA will be notified of any substantive changes. These changes, if necessaiy, wiU be discussed with and approved by EPA prior to implementation. Work will be conducted folioviring the procedures outUned tn the previously approved Work Plan. 3.1 Field Sampling Program 3.1.1 Soil and Groundwater Investigation at AST Area 3.1.1.1 Property Access and Well Permits ICC representatives have begun to secure offsite property access agreements. Prior to mobiUzation, ICC wUl make its best efforts to secure property access to offsite soil and groundwater sampling locations west of the AST area. Additionally, at this time ICCwUl attempt to gain access to all offsite weU locations described in Section 3.1.4.2. Prior to mobilization, HLA wiU obtain the appropriate permits from the Virgin Island Department of Planning and Natural Resources to instaU the proposed monitoring wells. 3.1.1.2 Soil Sampling SoU sampUng wiU be performed to (1) investigate the lateral and vertical extent of TEX tn soil offsite and adjacent to Tanks 8 and 9 (west of boring SBB17), (2) to assess the potential for other potential source areas in the general AST area, and (3) to coUect preUminary data regarding the applicabUity of soil vapor extraction in the AST area as a possible remedial altemative. Proposed boring locations are shown on Figure 3-1. Three soil borings vdll be instaUed along a 20-foot radiiis offsite (west) of previous boring SBB17. Three additional offsite borings may be instaUed based on photoionization detector (PID) field screening results and field observations. Four borings vdll be installed onsite vdthin the AST area north and south of the previously defined impacted area to investigate the potential presence of other source areas. The results from soU boring SBE-1 (installed during Phase I activities adjacent to former Tank 20; no PID readings were measured and no VOCs were detected above the detection limit in samples collected from the boring instaUed at this location) will be used in conjimction with data from the four new borings to evaluate the general AST area. SoU sampUng wiU foUow the detaUed procedures that are described tn the EPA-approved Work Plan and supporting documents and which have been implemented by HLA in previous phases of this RI. At each boring, soil samples vdU be collected continuously from ground surface to the water table using a spUt-spoon. Upon opening the spUt-spoon, the sample wUl be physically scored and screened for the presence of organic vapors using a PID. A sample from each 2-foot interval vdU then be immediately placed into a laboratory-prepared container. Additional sample volume from each interval wiU be placed into resealable plastic bags and screened in the field for headspace organic vapors using the procedures described in the Work Plan. Procedures for sample handling, management, and shipping wiU be implemented as described in the Work Plan. Two soU samples from each boring wUl be analyzed: one from directiy above the water table and one from the sample interval with the highest PID reading. Soil samples wUl be analyzed for target to compound Ust (TCL) VOCs. ° Shelby tube samples wUl be coUected from two of the onsite borings for analysis of grain size, (x) moisture, total organic carbon (TOC), and porosity. The samples vdll be collected from borings that '^ exhibit the lowest PID readings. These samples vdll be collected using 3-inch outside diameter Shelby tubes. The Shelby tubes will be constructed of stainless steel tubing or equivalent materials. C:\WORK\3524l\rdadd3ml.DOC Harding Lawson Associates 6 DRAFT The lower end is beveled to form a tapered cutting edge. The upper end of the Shelby tube is fastened to a check valve that helps hold the sample in place as it is being withdrawn. The Shelby tube is positioned at the upper portion of the interval to be sampled, and advanced the length of tUe tube (typically 2 feet). The advancement of the Shelby Tube is performed smoothly and steadUy by the application of hydrauUc pressure from the driU rig to the drilling rod connected to the Shelby tube. The Shelby tube is extracted using the same mechanisms operated tn reverse. Storage, shipping and handUng of these samples is described in the revised draft SAP. The analysis of the Shelby tube soU samples wiU be performed by Raytheon Environmental Services Laboratory located in Boothwyn, Pennsylvania. Two soil samples wUl be coUected from two separate onsite soU borings for analysis of total heterotrophic plate count and a hydrocarbon utiUzer (HCU) bacteria count These two soU samples vdU also be submitted for analysis to evaluate the available nutrient levels. The nutrient profile vdU include analysis of TOC, alkaUnity, iron, ammonia, sulfate, sulfide, nitrate, nitrite, pH, and ortho phosphorus. One of the soU sampling locations for the bacteria counts wiU be coUected from a soU samphng interval which exhibits relatively high PID readings. The remaining sample wiU be coUected from a sampling interval which exhibits moderate PID readings. Analysis of total heterotiophic plate count and a HCU bacteria count samples wiU be performed by HLA, if approved by EPA. 3.1.1.3 Offsite Sliallow Groundwater Investigation The purpose of this task is to determine the areal extent of the dissolved TEX in groundwater, where the TEX concentrations exceed their respective MCL. Groundwater samples vdU be coUected at the water table at three locations along a 50-foot radius west (offsite) of MW-6 using temporary monitoring wells. The temporary well points vdll be constructed of 2-inch diameter PVC screen and riser. A 5-foot long screen vdll be positioned across the static water level. A 6.5-inch diameter boring for the temporary wells will be advanced using hollow-stem auger drilling methods to a depth approximately 4 feet below the water table. The water table vdll be located by evaluating spUt-spoon samples coUected from the borehole. The temporary well vdll be installed through the auger and the augers vdll be removed. The water level measuring points will be marked and later surveyed to allow for groundwater elevation calculations. An oil-water interface probe will be used to measure static water levels and monitor for the presence or absence of Uquid phase hydrocarbons in each temporary weU. After allowing sufficient time for groundwater to equilibrate, a teflon baUer wiU be lowered into the weU to retrieve a groundwater sample which vdll be transferred to laboratory-cleaned 40-mL glass vials. The groundwater sample wiU be immediately analyzed onsite using a portable gas chromatograph (GC) calibrated for TEX. The groundwater samples that are collected vdll be placed tn the purge and trap vessel, extracted and analyzed. The data collected through field GC screening is classified as screening level data, Further investigation vdU be guided by the results of the onsite GC analysis of the three temporary weU samples. If TEX concentrations exceed their respective MCLs, then additional groundwater samples wiU be coUected by installing additional temporary weUs using the above procedures at incremental 50-foot radius sample locations (i.e., approximately 100 feet from MW-6). If the results of all three of the first groundwater samples collected from the initial temporary weU are below MCLs, then a 4-inch diameter monitoring weU vdll be instaUed at the furthest downgradient or western location. The weU vdll be instaUed and developed as described in the RIWP. The weU screen wiU be 10 feet long, have a slot size of 0.020 inches, and extend approximately 5 feet below the encountered water table depth. Development water vdll be placed in 55-gallon drums and staged onsite pending disposal. The temporary weUs wiU be removed vdthin 48-hours after their instaUation. The PVC screen and riser vdU be extracted and the borings vdll be abandoned as described in the RIWP. G:\WORK\3524i\idadd3ml.DOC Harding Lawson Associates ' ^ 0 2 1 9 7 DRAFT 3.1.1.4 Onsite Deep Groundwater Investigation The vertical extent of VOCs in groundwater at the AST area wUl be evaluated by instaUation of a double-cased monitoring weU to be located near MW-6. A pUot soU boring vdU be advanced to a depth of approximately 5 feet below the encountered water table. No soU sampling wiU be performed in this boring (soil sampling was already performed in this area at SBBll and SBB17). A steel casing will then be grouted in place at that depth to prevent cross-contamination during deeper drUling. The steel casing vdll be installed as foUows. The pilot boring vdU be reamed to a diameter of 12-tnches to the designated depth using mud rotary driUing techniques. An 8-inch diameter steel casing vdth welded joints wiU then be lowered to the bottom of the boring and centered. Cement grout wiU then be emplaced in the annular space around the casing via a tremie pipe from the bottom up. The driUing fluid in the aimular space wUl be displaced by the grout, the drilling equipment wiU be decontaminated and the driUing fluid inside the casing wiU be circulated thoroughly vdth potable water untU visible driUing fluids have been removed and relatively clear water remains inside the casing. After the grout has set for at least 24 hours, a pUot boring will be advanced through the grout Depth- discrete Hydropunch® samples vdU then be coUected at 10-foot intervals (starting at the interval 5 feet below the steel casing). The Hydropunch® sampler is a specialized tool designed to obtain groundwater samples vdthin the saturated zone vdthout the installation of a monitoring well. It is constructed of stainless steel and Teflon vdth viton 0-rings. The Hydropunch® sampler is designed to be driven by the sUde hammer commonly used for obtaining spUt-spoon samples. The Hydropunch sampler vdll be removed from the boring between each sampling interval and decontaminated using procedures described in the SAP. When the targeted sample depth is reached, the Hydropunch® sampler is opened by puUing back the outside sleeve of the tool. Soil friction holds the drive cone in place as the sleeve moves up. Once opened, groundwater flows through the dedicated disposable screen into the tool from the surrounding fewmation. After allovdng sufficient time for groundwater to fill the sample chamber, a Teflon bailer vdll be lowered into the borehole to retrieve a groundwater sample which vdll be transferred to laboratory-cleaned 40-mL glass vials. These samples vdll be analyzed for TEX using the onsite field GC. The boring vdll be advanced to a depth where concentrations of any individual chemical do not exceed MCLs. The boring vdll then be advanced 10 feet below this depth, reamed to 8 inches in diameter and a 4-inch diameter monitoring well wiU be installed, using the procedures outiined in the SAP. A diagram of the proposed double-cased well is provided as Figure 3-2. 3.1.1.5 Aquifer Testing Preliminary information on the hydrogeologic properties of the shaUow and deep portions of the water-bearing zones vdll be obtained by conducting the following activities. During development of the newly installed wells, water levels wiU be continuously monitored in the well being developed and in the nearest (or nearby) adjacent wells either manually or by using an automated data logger- pressure transducer system. This wUl provide information regarding possible hydrauUc coimection between the shallow and deep portion of the water-bearing zone. Monitoring of recovery of water levels in selected onsite wells after development vdll also provide limited information on relative hydrauUc conductivity between the upper and lower portions of the aquifer. Slug tests vdU also be performed at shaUow and deep wells to supplement the data coUected during weU development 3.1.1.6 Survey The coordinate location and elevation of the temporary wells, soU borings and new wells wUl be surveyed as specified in the Work Plan. The horizontal position wiU be surveyed vdth respect to the to Puerto RicanA'^irgin Islands plane coordinate system (North American Datum of 1983, or NAD 83) and ^ existing monitoring wells to the nearest tenth of a foot The well locations vdU be converted from f_» plane coordinates to latitude and longitude. ^ 00 G:\WORK\3524l\rdadd3ml.DOC Harding Lawson Associates 8 DRAFT The vertical position of the temporary weUs, soU borings, and new weUs wUl be surveyed vdth respect to Mean Sea Level (MSL) to the nearest hundredth of a foot WeU elevations to be surveyed include the top of inner casing, top of outer casing, and adjacent ground surface. The location of the inner casing elevation measurement wUl be permanentiy marked for future water level measurements. Temporary well elevations to be surveyed include the top of casing and adjacent ground surface. The ground surface at each of the soU borings wUl also be surveyed. 3.1.2 Site-Wide Groundwater Quality Sampling After instaUation and development of the new weUs in the AST area, groundwater samples wiU be coUected from the onsite and offsite monitoring weUs and the deep production weUs P-1 and P-2. The site-vdde groundwater sampling wiU be conducted to further evaluate groundwater quaUty at the site. SpecificaUy, objectives of the site-vdde groundwater sampling are (1) to evaluate the extent of TEX compounds related to the AST area, and (2) to assess the presence of chloroform previously reported at MW-2. Groundwater sampling vdU be conducted approximately 2 weeks after installation and development of the new wells. At the request of EPA, low-flow (minimal drawdown) groundwater sampUng procedures (as described tn Puis and Barcelona, 1995) wiU be utiUzed in place of the procedures described in the Work Plan. A 2-inch diameter Grundfos® Redi Flo 2 submersible ;5ampling pump or a bladder pump wiU be utiUzed for purging and sampling. As recommended by Puis and Barcelona (1993), HLA wiU purge and sample using a flow rate not to exceed 0.5 Uters per minute. A water quality probe vdU be used to measure key indicator parameters (temperature, pH, specific conductance, redox, dissolved oxygen, and turbidity) during purging. After stabilization of the water quaUty indicator parameters, groundwater samples vdll be collected directiy from the pump discharge line. Sample containers, preservation, shipping, and chain-of-custody procedures wiU be implemented as described in the Work Plan. Groundwater samples vdll be analyzed for TCL VOCs using CLP protocols. As requested by EPA, local precipitation records for the two-week period prior to each groimdwater sampling event vdU be submitted when presenting groundwater analytical data. 3.1.3 Onsite Groundwater Elevation Monitoring Groundwater elevations have been monitored at the site using automatic water level recorders (TUBERs) mstalled at MW-1 and MW-3 in August 1995 and at MW-4 and MW-5 in April 1996. Four recorders are currentiy instaUed. The most recent data (since June 1996) vdU be downloaded from these recorders during the upcoming field program. These data wiU be combined vdth water levels which vdll be measured manuaUy from all wells prior to the site-vdde groundwater sampUng event Groundwater contour maps wiU be prepared for multiple dates using the water table elevations calculated from the manual and automated measurements. 3.1.4 Evaluate Groundwater Flow Direction. In Deep Water*Bearing Zone HLA has recentiy received documents from the U.S. Geological Survey (USGS) entitied Water Resources Data Puerto Rico and the U,S. Virgin Islemds Water Year 1992, USGS Water-Data Report PR- 92-1,1993 and Water Wells on St Croix, U.S. Virgin Islands, Open File Report 91-503. 1994 . HLA has also requested the most recent Water Resources Data report and any other relevant information concerning water level data on St. Croix from the USGS. HLA vdU utiUze these data in conjunction vdth information obtained from the onsite and offsite deep wells, as described below, to estimate the regional flow direction of the deeper portion of the water-bearing zone. 3.1.4.1 Onsite Deep Wells The onsite deep production weUs (P-1 and P-2) wUl be evaluated using a downhole television camera to determine the actual well integrity and screen interval. After the survey, water levels vdU be measured at P-1 and P-2. These data vdU be combined with water level data from the new deep weU to be installed in the AST area to preUminarily evaluate onsite flow direction in the deep water- bearing zone. G:\WORK\3524l\rdadd3ml.DOC Harding L^wson Associates 3 0219 9 DRAFT 3.1.4.2 Offsite Deep Wells The purpose of this task is to survey the locations and elevations of aU offsite wells to which access is granted vdthin a 0.25-nule radius of the site, and to measure groundwater levels in these weUs to aid in evaluation of regional flow direction in the deep water-bearing zone in the vicinity of the site. The existence of these weUs, or their accessibiUty, has not been field verified. The locations have been plotted based on existing records and aerial photograph review. The offsite groundwater production weUs proposed to be surveyed include (see Figure 3-3): Former WAPA weU direcUy south of site Well at CharUe's Concrete Company (east of site) Well at Meridian Engineering (northwest of site) Virgin Islands Port Authority (VIPA) WeUs 1 and 2 (west of site) U.S. Geological Survey weUs downstream of the site near confluence vdth Bethlehem Gut Well at Virgin Islands Paving Inc. (northwest of site). Prior to mobiUzation for the field samphng program, ICC wiU make its best efforts to secure property access permission from the owners of the above wells, and vdll attempt to obtain relevant available information regarding the constniction, usage, and status of these wells. The horizontal and vertical positions of these wells vdll then be surveyed following the procedures described in the Work Plan. Groundwater levels vdll then be measured at the wells using the procedures outiined in the Work Plan. The groundwater elevations calculated from the offsite and onsite deep wells vdU be used to evaluate flow direction in the deep portion of the water-bearing zone. Water level contour map(s) vdll be prepared. 3.1.5 Storm Drain and River Gut Sediment Sampling Three samples of River Gut sediments vdll be collected at the onsite, upsfream and downstream locations shown in Figure 3-4. Samples SDl, SD2, and SD3 vdll be collected from the central storm drain system. Samples SD4 and SD7 vdll be collected from sediments, if present, in the southem storm drain system. These samples can only be collected if sufficient material exists for analytical purposes. Locations may have to be modified in the field to depositional areas where adequate sediment volumes are available. Sample SDl vdU be collected from the storm drain at a point approximately 25 feet below the process area. Sample SD2 wiU be coUected from the junction of the Unes forming the central storm drain system. Sample SD3 wiU be collected from the settUng basin which collects drainage from the central storm drain system before discharging to the River Gut. Sample SD4 wiU be coUected from vdthin the southem storm drain system at a point approximately 10 feet upgradient of the point where this system discharges to River Gut Sample SD7 wiU be coUected from sediments, if present, vdthin the southem storm drain system at a point approximately 50 feet upgradient of SD4. Samples RGl A through RGll vdll be collected from the River Gut sfream channel. Samples RGlA, RGlB, and RGlC vdll be located in the field at locations upstream of the abandoned raUroad bridge, and upstream of drainage from the buUdozed area adjacent to the site vdthin relatively close proximity (less than 25 feet) of each other vdthin the River Gut. These samples wiU be evaluated as backgroimd sediment samples. Sample RG2 wiU be collected approximately 100 feet upstream of the site boundary just downstream of the abandoned raUroad bridge. Sample RG2 vdll be collected from _ the northeastern sfream bank in an area of non-site-related waste material observed in the fiU. Sample to location RG2 is located at a seep of pefroleum-Uke material visually identified in the fill material on ^ the northern bank of the River Gut Sample RG3 vdU be coUected from the center of the sfream bed o upstream of the former lab drain discharge. Sample RG4 vdll be collected from the center of the G:\WORK\3524l\rdadd3ml.D0C Harding Lawson Associates 10 to o DRAFT stream bed below the former lab drain. Sample RG5 wiU be coUected from the center of the stream bed approximately 100 feet downstream from RG4. Sample RG6 wiU be coUected in an area of non-site-related waste material observed in the fiU on the northeastern side of the River Gut bank. Sample RG7 vdll be coUected from the River Gut stream bed at a point approximately 50 feet upstream from where the central storm drain system from the site discharges to River Gut Sample RG8 wiU be coUected from the River Gut stream bed at a point where the central storm drain system from the site discharges to River Gut. Sample RG9 wUl be wiU be coUected from the River Gut stream bed at the point where southem storm drain system from the site discharges to River Gut Sample RGlO wUl be collected from sediment deposits on the upgradient side of the berm located in the River Gut channel near the site. Sample RGll wUl be collected from sediment deposits on the upstream side of the sheet piling instaUed in the River Gut stream charmel, downstream of the site. Samples RGl2 and RGl3 vdll be held in reserve and may be selected as additional sampUng locations in the field. Several areas of non-site-related waste material have been observed during previous studies tn the northeastern stream bank opposite the site. Samples RG12 and RG13 wtU be reserved for collecting sediments from the northeastern stream bank in an area of observed non-site-related waste material not already targeted by this investigation. The samples vdll be analyzed for TAL metals, total organic carbon, particle grain size, pH, redox, and conductivity. 3.2 Data Validation Confirmation level laboratory data generated for investigative samples vdll be validated as discussed in the Work Plan. 3.3 Data Evaluation The data generated during this phase of the RI vdll be evaluated in conjunction vdth the data previously generated and reported by HLA (1995, 1996). The data vdll be evaluated to gain further information on the follovdng: • Onsite and offsite extent of TEX in soil and groundwater in AST Area • Potential extent of chloroform, if any, in groundwater • Flow direction(s) in the shaUow and deep portion of the water-bearing zone • Onsite sediment and River Gut sediment TAL metals concentrations 3.4 Update/Track ARARs The Ust of AppUcable or Relevant and Appropriate Requirements (ARARs) vdU continue to be refined, developed, and revised, as needed, throughout completion of the RI activities to take into consideration additional chemical data, site conditions, and potential remedial actions. Further, state and federal registers vdU continue to be reviewed periodicaUy to identify changes to the ARARs that have already been identified. G:\WORK\3524i\rdadd3ml.DOC Harding Lawson Associates 302201 '*'' DRAFT 3.5 Profect Meetings and Reporting 3.5.1 Meetings witli EPA One meeting vdth EPA wiU be requested foUovdng receipt, interpretation, and vaUdation of data generated during the implementation of this RI Work Plan Addendum and prior to preparation of a final Draft Data Summary Report Addendum (DSRA) or preparation of the RI, whichever is appropriate. At that time, the findings vdU be discussed along vdth the format for the final Draft DSRA. Additional meetings vdth EPA wiU be conducted as needed or upon request 3.5.2 Monthly Progress Reports Monthly progress reports vdU continue to be submitted to EPA on the 15th day of each month. The monthly progress reports vdU be prepared in accordance vdth the Administrative Order on Consent and the Work Plan. 3.6 Management of lnvestlgatlon*Derived Waste Investigation-derived waste (IDW) vdU be managed in accordance vdth procedures outlined in the Work Plan. to o to lO o lo G:\WORK\3524i\jdadd3ml.DOC Harding Lawson Associates 12 DRAFT 4.0 ANTICIPATED SCHEDULE To be developed 302203 G:\WORK\35241\rdadd3inI.DOC Har«lln« I — — * «-•'— FIGURES 302204 \nMm^my------yz^''^' tsXzV-AmiZ^vk^^-^ • \y.%. 'k^ ;^^...^iW^vmp^-^'''^V^ -f- L.yyz:^y_y ' 'y""A'k^-^k^kz^ :. •\ , j b ^ J -^ z-zky^yH''—~ r-y^^—^^^'^y-' '-ykzyzyyk^:<k: . -y-Z-yZZXrie^'-. '-. Zy^::^<t'- - Z - '\ '•• \ '••.'^i-<^.^i::i^'"'-^fi~'-, •-..\^Z:r^''..-'' U.^''"* A-'^mykyy AyyyzkMyzkmk.. • - I y •^Z'-kytrykk''''ki-'-'^'yyy7--^'..'--:r' -•'7 - > - 3 ^ v \ ^ i C i i - ^ v - ; .; : • -iy-::y;;..r y .\ ^ • .- v^>-^- :^ •^,^=-^- Ji-jX .-, -.•> — -'^ • • - -,^==---- ^k^s'k- k^^Sfk^y^^^kyykkz^^~y^=y lluidmg Lnwson Associatw tnginesnng ond , _ Environmental Services i - ' J l North Third S l r „ l SITE LOCATION MAP FIGURE * « 3524iAnA' HtVIS£D DArE o CO X CO ^ . • in or UJ _J UJ SQUSCEi. ^OAPTEO rpou s,H U.P. . CKHMicu ST. cHcx. u.s.v.,. Br .as co.Po«A.o. aacu..KT C . - . 0 , - 0 . - . . U.O.TtO o NJ to o sv s r 6 4-50' 4 S ' 4 S ' 4 2 ' 6 A' • * B ' 4 6 ' 1- \T*r ^ ../ A! / /? // /••• k X jAU mvii« i J i u « « t ^ /'Z:-:^^/^^-Y.iy'Z:ZzZ:Z:Z:y:-*:ZiJt< , y ^ \ ^ •;<!'v:::--:Sv::.;V;::.,.:„E^ * CRANOC P B t N C C l S t S T p8l "mmm C D I D I N ROCK C H R I t l l A K I T C O MM iy-ikkA'^Mkyky^zy Hording Lawson Associolea Engineering n n d E n v i r o n i n e n l o l Services U l Norlli Ihird S i t e d Philarielpliio. Pennsylvunio ) 9 I 0 S 2 1 5 - 6 2 7 - 4 5 0 5 ORAWN WGA jon mjMnCR 352-11.5 REGIONAL GEOLOGICAL MAP VIRGIN ISLAND CHEMICAL SITE S(. Croix. U.S. Virgin Islonds FIGURE 1-3 APPROVED DRAWINC NUMBER DAIE 11/5/96 REVISED DAfE V90220£ B Complete 4 soil borings in AST area Determine horizontal and vertical extent of affected soils offsite, related to the identified onsite source area associated with the AST farm that may be octinq OS on ongoing source of groundwoter contominotion. Secure access to offsite property for soil boring and well installation • B — • Select location for additional offsite boring radially outward from this location. Reld screen samples for organic vapors using PID Collect soil samples from boring at selected |4- location Evaluate dota Submit two samples from each boring for laboratory analysis Reld screen samples for organic vapors using PID Evaluate data. Select location for deep well to assess vertical extent of affected groundwater associated with AST area No Submit two somples from each boring for laboratory analysis - r Install deep monitoring well at location near MW-6 Assess locotionCs) for additional offsite and onsite soil borings to define extent of impacted soil. 1 Begin Temporory Well sampling program to assess horizontol extent of offected groundwater near AST area. Soil Sample Data collection task completed. Proceed to Temporary Well Sompling Program Nok Select additional location 50 feet radially outward from boring sampled Mobilize to planned iocotion for Temporary Well. Advance boring to 4 ft below water table ond install Temporary Well. Collect groundwater sample. No k if data suggest possi offsite source area, holt I program, confer with EPA y Install shallow monitoring well ot furthest downgradient location sampled Secure access permission from owners of nearby wells. Obtain available relevant information on well construction, usage and status. Survey offsite wells and measure water levels ^No^ Collect complete round of groundwater samples deep—zone groundwater flow map. - & Prepare Data Summary Report Addendum Harding Lawson Associates Engineering ond E n v i r o n m e n t o l Services 14 Woshington Rood Princeton Juction, New Jersey 08550 609-936-0700 FLOW CHART VIRGIN ISLAND St. Croix, U.S. CHEMICAL SITE Virgin Islands FIGURE 2-1 DRAWN WGA JOB NUMBER 35241.5 APPROVED owe. No. 35241B06 DATE 1/20/97 REVISED DATE z.os3oe SBB9 ri ri +! I - I l - l LJ LJ e + + + 'SBBIO ^ B B 14 ® SBBhl + SBB2 SBB80 ® M W - 1 O SBBll 3 ri I -I I • i l LJ ri^ri I 2 l I 5 l I ^1 I ^1 LJ LJ © SBB6 ^ ^''S'^® SB-S7 ^SBB5 SBB3 ^ B B 4 0SBB16 ABOVEGROUND TANK FARM E A H l M i N ULKM " ^ B Q I S WALL •^1 LJ RAMP ri ri ri ri I - } | I 2 l I r;l I « l I • i l I • i l LJ + I • i l LJ 30 60 90 ft. FOR ILLUSTRATION PURPOSES ONLY LEGEND + A PROPOSED TEMPORARY MONITORING WELL LOCATION PROPOSED SOIL BORING LOCATION PROPOSED DEEP MONITORING WELL LOCATION © CZD CID LJ^ SBEl © PREVIOUS SOIL BORING LOCATION MONITORING WELL LOCATION EXISTING ABOVEGROUND STORAGE TANK TANK PAD-FORMER ABOVEGROUND STORAGE TANK LOCATION 8 0 3 3 0 e Harding Lawson Associates Engineering o n d E n v i r o n m e n t o l Services 14 Woshington Rood Princeton Junction, New Jersey 06550 6 0 9 - 9 3 6 - 0 7 0 0 PROPOSED SAMPLING LOCATIONS VIRGIN ISLAND CHEMICAL SITE St. Croix, U.S. Virqin Islands FIGURE 3-1 DRAWN WGA JOB NUMBER 35241.5 APPROVED DRAWING NUMBER 35241A11 DATE 11/7/96 REVISED DATE ^LOCKING PROTECTIVE CASING GROUND SURFACE r T ^ T y j ' y y y " y / / A ^ " CEMENT CEMENT BENTONITE- SLURRY 8" STEEL CASING SL RLTER PACK SANO 4" WELL SCREEN 8" BOREHOLE- ^ , V. 'A GROUT 12' BOREHOLE y WATER TABLE Ul Hi in 4 ' WEa CASING •BENTONITE SEAL (2 FEET MIN.) Ui li! Harding Lawson Associates Engineering ond Environmentol Services 14 Woihlnglon Road Princeton Juclion, N n Jersey 609-936-0700 ORAWN JSW/WGA JOB NUMBER 35241.5 R2y,ii?|-CASED MONiTORlNG WEU." CONSTRUCTION DIAGRAM VIRGIN ISLAND CHEMICAL SITE St. Croix. U.S. Viroin Islonds A>>PROVEO DRAWING NUMBER 35241A07 to o to IO o VD riGURE 3-2 DATE 11/7/96 REVISED OATE GOLDEN GROVE ADULT CORRECTIONAL FAOUTY UNDEVa.OP£D i..,i i . *,A * ,* A * > , » i.».J..t.J.J..I.....^ JV,A >.*_*.A>.A MERIOAN ENGINEERING COMPANY • 7 ^ LEGEND EXPECTED LOCATION OF OFFSITE \ « L L S CO O to to H O FOR ILLUSTRATION PURPOSES ONLY Harding Lawson Associates Engineering and Environmentol Services 14 Woshington Rood Princeton Juction, New Jersey 08550 609-936-0700 APPROXIMATE LOCATION OF OFFSn'E PRODUCTION WELLS VlRCiN ISLAND CHEMICAL SITE St. Croix, U.S. Virgin Islands FIGURE 3-3 DRAWN NUMBER APPROVED DWG. No.. OATE RF\/n;rn niir RG-1A RG-1A. RG-1B and RG-1C will be field located above abandoned railroad bridge and bulldozed fill material area. LEGEND Abandoned Railroad Bridge ,RG-2 MW-6 UNPAVED IIIIIII ^ZZD MW-1 !| El 13 H a 15! [51 [Hi Isj ffj fa^^°8^, J 0 y i3 13 lil 13 lil d S 13 p-2 TANK FARM CONCRETE PADS y . DRIVEWAY WALL EARTHEN BERM RAMP r /O rn o LO cn o -< UNPAVED SUMP I PAD GENERATOR [ BUILDING UNPAVED SCALE P - 1 — D P F R — REACTOfi I AREA I , P 10 CONCRETE I TREltJCH 1 , 1 1 I I ) , , i l l , , , ! , , — TOWER I, PROCESSio' MW-2i CONCRETE- S D - 3 ^ P I T L I CISTERN SD-Sl DRYER y ^ y ^ ^ - - ^ BUILDING <Q: Ho t r o I -" J— I DRAF LABORATORY SOURCE: SITE MAP, VI CHEMICAL, ST. CROIX, U.S.V.l. BY NUS CORPORATION DOCUMENT 02-9101-04-51, UNDATED AND AERIAL PHOTOGRAPHS PROPOSED SEDIMENT SAMPLE LOCATION MONITORING WELL LOCATION PRODUCTION WELL LOCATION STORMWATER INLET EXISTING ABOVEGROUND STORAGE TANK TANK PAD-FORMER ABOVEGROUND STORAGE TANK LOCATION 80 160 240 ft. FOR ILLUSTRATION PURPOSES ONLY CONCRETE PLANT Location of samples RG-10 and RG-11 is southeast of site on up—stream side of USGS installed berm and Sheet Piling respectively. RG-11 Harding Lawson Associates Engineering o n d E n v i r o n m e n t o l Services 14 Woshington Rcx)d Princeton Juclion, New Jersey 08550 6 0 9 - 9 3 6 - 0 7 0 0 PROPOSED LOCATION OF ONSITE SOIL AND RIVER GUT SEDIMENT SAMPUNG FIGURE VIRGIN ISLAND St. Croix. U.S. CHEMICAL SITE Virgin Islonds 3-4 DRAWN .inR NIIURfO «ODDr*\rtm DRAFT Harding Lawson Assoclat«s APPENDIX AB Containers, Preservation, Packaging, and Shipping Requirements to O to to l-» H > g:\work\35241\ldadd3inl.doc Appendix AB. Containers, Preservation, Packaging, and Shipping Requirements r * ^ 0 A P ' T Island Chemical Company | -, f t ^ i \ 1 " 1 St. Croix, U.S. Virgin Islands " • ' ' ^ ^ * * • • Analysis Containers Preservation Teclinical Holding Time' Volume of Container Shipping Normal Packaging Groundwater Organic Analyses TCL VOCs TCL SVOs Pyridine Three 40-ml glass vials with Tellon 1:1 HCl to pH <2, cool to 14 days septum-lined caps <-4°C in dark storage Fill completely, no air bubbles Two 1-liter amber glass bottles with Cool to 4°C in dark Teflon™-lined caps storage Two 1 -liter amber glass bottles with Cool to 4°C in dark Teflon -lined caps storage Extract within 7 days, analyze Fill 90% full within 40 days after extraction Extract wilhin 7 days, analyze Fill 90% full within 40 days afler extraction TCL Pesticides Two 1-liter amber glass bottles with Cool to 4°C, NajSjOj Extract within 7 days, analyze Fill 90% and PCBs Teflon -lined caps Groundwater Inorganic Analyses TAL metals One 1-liter polyethylene bottle (unfiltered) TAL metals (filtered) Cyanide One 1-liter polyethylene bottle One I-liter polyethylene bottle HNOj to pH <2.0 HNOj to pH <2.0 within 40 days after extraction 6 months, except Hg - 28 days Fill 90% 6 months, except Hg - 28 days Fill 90% NaOH to pH > 12, cool to 14 days 4°C Fill 90% Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack H Ol CN O ro SoU Organic Analyses TCL VOCs One 120-ml vial with Teflon™- Cool to 4°C in dark septa lined lid storage TCL SVOs and Two 16-oz. amber glass jars with Cool to 4°C in dark Pyridine Teflon^lined lid storage TCL Pesticides One 4-oz wide-mouth glass jar with Cool to 4°C and PCBs Teflon™-lined lid 10 days Extract within 7 days and analyze within 40 days after extraction Extract wilhin 7 days and analyze wilhin 40 days after extraction Fill completely Fill 90% Fill 90% Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of colleclion by overnight carrier Bubble pack Bubble pack Bubble pack Revised January 20, 1997 G.\WORK\35241\RIWPA\ABTAB.DOC HARDING LAWSON ASSOCIATES of 3 Appendix AB. Containers, Preservation, Packaging, and Shipping Requirements Island Chemical Company St. Croix, U.S. Virgin Islands DRAFT Analysis Containers Preservation Technical Holding Time' Volume of Container Shipping Normal Packaging SoU Inorganic Analyses TAL Metals One 8-oz wide-mouth glass jar with Cool to 4°C Teflon™-lined lid Cyanide One 8-oz wide-mouth glass jar with Cool to 4°C Teflon™-lined lid 6 months, except Hg - 28 days Fill 90% 14 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Ship within 24-hours of Bubble pack collection by overnight carrier ro H CN CN o CO Nitrate/Nitrite One 32-oz glass bottle Cool to 4°C 28 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Sulfate One 32-oz glass bottle Cool to 4°C 28 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Sulfide One 32-OZ glass bottle Cool to 4°C 7 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Iron (total) One 8-oz wide-mouth glas< jar with Cuol lu -t'C Tenon™-lined lid 6 months Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Alkalinity One 32-oz glass boulc t oul lo 4*C 14 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Ammonia One 32-oz glass bottle Cool lo 4°C 28 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Ortho phosphorus One 32-oz glass bottle pH One 32-oz glass bottle Cool to 4°C Cool to 4°C 48-hours As soon as possible Fill 90% Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Ship within 24-hours of Bubble pack collection by overnight carrier Total Organic Shelby Tube Carbon None 28 days Fill 90% Ship within 24-hours of Bubble pack collection by overnight carrier Revised January 20, 1997 G:\WORK\35241\RIWPAVABTAB.DOC HARDING LAWSON ASSOCIATES 2 of 3 Analysis Appendix AB. Containers, Preservation, Packaging, and Shipping Requirements Island Chemical Company Sl. Croix, U.S. Virgin Islands Containers Preservation fcchnical Holding Time' Volume of Container DFAFT Ship|)lng Normal Packaging Moisture Grain size Porosity HCU bacteria Count Total plate bacteria count Shelby Tube Shelby Tube Shelby Tube 500-ml Glass 500-ml Glass None None None As soon as possible None Set None Set Fill 90% Fill 90% Fill 90% Cool to 4°C Cool to 4°C 24-hours or as soon as possible Fill 90% 24-hours or as soon as possible Fill 90% Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship within 24-hours of collection by overnight carrier Ship wilhin 24-hours of collection by overnight carrier Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Parameters and detection limits will be consistent with methods listed in Tables Cl-2 through Cl-7 of the Quality Assurance Project Plan Sample containers will be prepared according to OSWER Directive No 9240-05-05A, "Specification and Guidance for Obtaining Contaminant-Free Sample Containers, (December 1992)" or certified clean containers (e.g., I-Chem 300 series) will be used Ccrtilicala uf aiul>u> vait>in); uiiij>le u>ntaincr cleanliness will be retained and available for review by USEPA. ' The time of sample colleclion lo extracliun *nal>> g gram HNO3 nitric acid oz. ounce VOCs volatile organic compounds IKI h>\k»>.hl»ric acid nii millililcr !iVO> teniivulatilc organic compounds > greater than HjS04 sulfuric acid NaOH sodium hydroxide TAL Target Analyle List °C degree Celsius Hg mercury NazSjOj Sodium thiosulfate TCL Target Compound List H CN CN O ro Revised January 20, 1997 G:\WORK\35241\RIWPA\ABTAB.DOC HARDING LAWSON ASSOCIATES 3 of 3 APPENDIX AO CONTENTS ADl INTRODUCTION 1 ADZ FIELD INVESTIGATION PROGRAM 1 AD2.1 Stream Sediment Sampling 1 AD2.1.1 Sediment Sampling When Stream is Dry 1 AD2.1.2 Sediment Sampling When Stream is Flowing 2 AD2.2 Shelby Tube Soil Sample Collection 2 AD2.3 Hydropunch® Groundw^ater Sampling 3 AD2.4 Mud Rotary Drilling Methods 4 AD2.5 Monitoring Well Installation 5 AD2.5.1 Double-Cased Well Construction, 5 AD2.5.2 Temporary Monitoring Well Construction 6 AD2.6 Low^ Flow Purging and Groundwater Sampling 6 AD2.7 Onsite VOC Analysis by Gas Chromatograph 10 AD2.8 Aquifer Slug Testing 10 302215 AOI INTROOUCTION Harding Lawson Associates (HLA) has prepared this addendum to the EPA-approved Remedial Investigation Work Plan (RIWP) - Sampling and Analysis Plan (SAP) (HLA, 1994) on behalf of Island Chemical Company, Inc. (ICC). This SAP Addendum will be included in the RIWP as Appendix AD in support of the RIWP Addendum (RIWPA) and responds to requirements set forth in the National Contingency Plan. The RIWPA includes the following activities which were not specified in the original RIWP: Collection of stream sediment samples Collection of undistiirbed soil samples using a Shelby tube sampling device Collection of groundwater samples using a Hydropunch® sampling device Onsite analysis of groundwater samples using a portable gas chromatograph (GC) Installation of soil borings and monitoring wells using mud-rotary drillirig methods Installation of temporary monitoring wells Installation of double-cased monitoring wells Collection of groundwater samples using low-flow groundwater sampling procedures Estimation of hydraulic properties of the shallow aquifer using slug testing methods Procedures for additional activities planned during the implementation of the RIWPA are described in the SAP, Appendix A of the original RIWP. AD2 FIELD INVESTIGATION PROGRAM Specific field procedures to perform the activities identified in Section ADl above are presented in this addendum. AD2.1 Stream Sediment Sampling Efforts will be made to collect stream sediment samples when River Gut is not flowing. Section AD2.1.1, presents the sampling procedures to be followed if the stream is dry. However, if it is necessary to collect sediment samples when River Gut is flowing, HLA will follow the sampling procedures described in Section AD2.1.2. AD2.1.1 Sediment Sampling When Stream is Dry 1. The proposed sample locations shown in Figure 3-4 of the RIWPA will be located by measuring from fixed visible reference points using a tape measure. 2. The area within roughly 10 to 20 feet of the proposed sample locations will be inspected visually to determine quaUtatively the area of greatest sediment deposition. This area will be ^ ^ selected as the final sampling location. o to to 3. A field-decontaminated, stainless steel trowel will be used to collect the sediment sample from the dry stream bed at the final sampling location. The trowel will be decontaminated ^ before use following the procedures specified in Section A2.4.2.2 of the RIWP. G:\W0RK\35241\R1WPA\SAP ADD.DOC HARDING LAWSON ASSOCIATES AD-1 4. The sediment sample vrill be transferred directly to laboratory-prepared sample containers which will then be sealed, labeled as described in Section A2.10.1 of the RIWP, and placed directly into a cooler with ice (approximately 4°C). 5. The final sample location will be marked and photographed to show its location with respect to fixed references. 6. The distance from each sampling point will be measured with respect to at least three fixed references and recorded to allow future relocation of the sample. AD2.1.2 Sediment Sampling When Stream is Flowing If possible, sediment sampling will be postponed until the stream is dry. If this is not practical, the stream sediments will be sampled using the following procedures: 1. Stream flow will be evaluated to determine if the stream can be entered safely. 2. Begirming at the furthest downstream location, HLA persormel will enter the stream at a location downstream of the proposed sampling location. All sample locations will be approached from the downstream direction to avoid disturbing upstream sediments that might be carried to downstream locations not yet sampled. 3. The proposed and final sample locations will be determined as described in Steps 1 and 2 of Section AD2.1.1. 4. A field-decontaminated Eckman Dredge sampler will be used to collect the sediment samples at each location. 5. The sediment sample will be transferred from the dredge to laboratory-prepared sample containers using a field-decontaminated stainless steel trowel. The sample container wdll then be sealed, labeled as described in Section A2.10.1 of the RIWP, and placed directly into a cooler with ice (approximately 4°C). 6. The sample location vrill be photographed and n^corded as described in Steps 5 and 6 of Section AD2.1.1. AD2.2 Shelby Tube Soil Sample Collection Soil samples will be collected from fine-grained matenal using a Shelby tube samphng device. The Shelby tubes vrill be approximately 2 feet long, 3 inches in diameter and constructed of stainless steel tubing or equivalent materials. The upper end of the Shelby tube vrill be fastened to a check value that helps hold the sample in place as it is being withdrawn. Field documentation and equipment decontamination vrill be conducted as specified in the RIWP. The following procedures will be used to obtain undisturbed soil samples using the Shelby tube: 1. The boring vrill be advanced to the top of the interval to be sampled. 2. The drill bit and drilling rods will be removed from the boring and a field decontaminated Shelby tube sampler will attached to the drill rod assembly and lowered to the bottom of the boring. 3. The Shelby tube will then be pushed to the required depth, if possible. The Shelby tube will be advanced by the application of hydraulic pressure from the drill rig to the drill rod assembly. 4. Once the Shelby tube has been advanced to the final depth, activities will be halted for several minutes to allow the soil sample to equilibrate within the Shelby tube. The drill rod assembly will then be rotated 1/4 to 1/2 turn to separate the sample from the underlying soils. G;\WORKV35241\RIWPA\SAP_ADD.DOC "3 fl 9 9 1 7 HARDING LAWSON ASSOCIATES AD-2 5. The rod assembly with the Shelby tube sampler will then be withdrawn from the boring. 6. The Shelby tube vrill be discoimected from the drilling rod assembly and approximately 1 to 2 inches of soil will be removed from the bottom of the tube after it is recovered. 7. Both ends of the sample will then be sealed with several inches of paraffin, liquefied by heating. Care will be taken to completely seal the ends of the soil sample to prevent moisture loss 8. Once the paraffin has dried, any void space in the top of the tube vrill be filled tightly vrith a packing material, such as crumpled paper. Each end of the tube will be secured with a plastic end cap taped in place. 9. The outside of the Shelby tube vrill be labeled to indicate the sample identification, date of sampling, and top of the sample. Care will be taken to keep the sample in an upright position during handling. Instructions will be provided to the carrier to ship the samples in an upright position. AD2.3 Hydropunch® Groundwater Sampling Groundwater samples will be collected from the pilot boring for deep moniloring well MW-6 in the Above-ground Storage Tank (AST) area using a Hydropunch® sampling device. The Hydropunch® is a 5-foot long sampling device that consists of a drive point; 1-inch diameter, 4-foot long disposable screen; and a retractable stainless steel sleeve. The screen is made of poly vinyl chloride (PVC) or polypropylene. The Hydropunch® will be used to collect groundwater samples from selected depth intervals using the following procedures: 1. Once the boring has been advanced to the selected depth by the driller, the drill bit and rods will be removed. 2. The Hydropunch® sampler, equipped with an unused, disposable screen, will be attached to the drill rods and set at the bottom of the boring. 3. The Hydropunch® sampler will be driven into the formation using a 140- or 300-pound hammer. The Hydropunch® sampler will be driven 4-feet into the formation or until refusal is encountered. A total of 100 blows over a six-inch interval will be considered refusal. The number of blows and distance driven vrill be recorded. 4. If the Hydropunch® sampler is driven less than 1-foot before refusal is encountered, no sample will be collected, the boring vrill be advanced 5 feet, and a second attempt will be made to drive the Hydropunch® sampler into the formation. 5. If the Hydropunch® sampler is driven 1-foot or more, the sleeve will be retracted approximately one-half the distance that the sampling device was driven (i.e., retract the sleeve 2 feet if the sampler is driven 4 feet), exposing the disposable screen to the formation. Sufficient time will be given to allow groundwater to flow into the Hydropunch®. An electronic depth-to-water probe will be lowered inside the drill rods and Hydropunch® to monitor groundwater recharge. 6. Groundwater will be allowed to equilibrate in the Hydropunch® for a minimum of 30 minutes or until the water level inside the drill rods has reached 90 percent of the distance from the water table to the bottom of the sampler. to 7. A field-decontaminated 1/2-inch diameter Teflon™ bailer will be lowered on Teflon™-coated ^ stainless steel cable through the Hydropunch® rods to collect a groimdwater sample from the ^j screened interval. Prior to use at each sampling interval, the Teflon™ bailer and cable will be decontaminated following the procedures described in Section A2.4.2.2. G:\WORK\3524l\RIWPA\SAP ADD.DOC HARDING LAWSON ASSOCIATES AD-3 00 8. The color, qualitative turbidity and other pertinent observations of the groundwater sample will be noted and recorded in the field book. 9. Approximately 20 milliliters (mL) of groundwater sample will be poured directly into an unpreserved 40-mL glass vial, and submitted for onsite analysis of toluene, ethylbenzene, and xylenes by the field GC as described in Section AD2.7. 10. Co-located groundwater samples vrill be obtained for laboratory analysis at a rate of one sample for every ten screening samples. HLA vrill submit a minimum of one groundwater sample for laboratory analysis collected from zones displaying no detected volatile organic compoimds (VOCs) by field screening. The co-located samples will be collected in 40-mL vials prepared by the laboratory, preserved in the field and submitted to the laboratory for analysis of Target Compound List (TCL) VOCs by Contract Laboratory Program (CLP) methodologies as specified in the RIWP. The co-located samples will be collected, preserved and handled as described in steps 23 through 27 of Section A2.8 of the RIWP. AD2.4 Mud Rotary Drilling Methods Mud-rotary drilling methods will be utilized to advance the deep boring for the double-cased well in the AST area. Mud-rotary drilling techniques are described below. Double cased well construction is described in Section AD2.5.1.1 1. Prior to set up, the drill rig and equipment vrill be decontaminated by steam cleaning and/or a potable water wash as described in Section A2.4.2 of the SAP. 2. The drill rig and mud tub will be placed at the selected drilling location. The mud tub vrill contain baffles to enhance settlement of solids entrained in the drilling fluid. 3. A tri-cone roller or wing bit will be attached to the drill rods. 4. The mud tub vrill be partially filled with potable water. The potable water will be obtained from the driller's office, consistent with previous work on this project. The driller will then circulate the water through the drilling tools and mud tub adding bentonite-based drilling mud as necessary to create a viscous drilling fluid. The amount of bentonite added and the viscosity of the fluid will be established in the field at the discretion of the driller. 5. Once the driller is satisfied that the drilling fluid is of adequate consistency, the driller will advance the borehole to the desired depth. During drilling, the drilling fluid will be pumped down through the drilling rods. The fluid will circulate to the ground surface by rising in the aimular space of the boring. Cuttings from the boring will be entrained with the rising fluid and will be separated to the extent possible in the mud tub at the surface. The viscosity of the fluid may be altered during drilhng activities at the driller's discretion by adding water or mud. 6. During drilling, solids will be removed from the mud tub as needed and containerized onsite in 55-gallon drums. Drimamed investigation-derived waste will be staged onsite until proper disposal arrangements are completed. 7. Soil samples will be collected and logged as described in Section A2.4.3 of the SAP. 8. The volume of drilling fluid lost to the formation will be monitored during drilling and recorded on the field boring log. G:\WORK\35241\RIWPA\SAP_ADD.DOC HARDING LAWSON ASSOCIATES AD-4 302219 AD2.5 Monitoring Well Installation Drilling methods for the installation of monitoring wells will be selected based on field conditions and the anticipated depth of the borehole. It is anticipated that the borings for the shallow soil zone vrill be drilled using hollow-stem augers and that mud-rotary drilling methods will be necessary for the installation of deeper wells. Mud-rotary drilling methods may also be necessary for installation of shallow monitoring wells if problems with auguring are encountered The procedures described below will be used to construct the proposed double-cased and temporary groundwater monitoring well. Procedures for well development and for construction of single-cased monitoring wells are described in Section A2.5 of the RIWP. Well construction details will be recorded by an HLA geologist. Equipment decontamination will be conducted as described in Section A2.4.2oftheRIWP. AD2.5.1 Double-Cased Well Construction The follovring procedures vrill be implemented during installation of the double-cased monitoring well at the site: 1. Prior to set up, the drill rig and equipment will be decontaminated by steam cleaning and/or a potable water wash as described in Section A2.4.2 of the SAP. 2. The driller will advance a 12-inch diameter boring to approximately 5 feet above the predicted water table depth using mud-rotary drilling techniques as described in Section AD2.4. The approximate depth to the water table will be estimated before drilling activities begin based on groundwater elevations measured at nearby monitoring wells. 3. Beginning at this depth, the driller will collect soil samples using a split-spoon sampling device as described in Section A2.4.3. Split-spoon samples will be collected continuously until the water table is encountered. An HLA geologist vrill examine the soil samples to determine the level of the water table. 4. The driller will then advance the boring to 5 feet below the water table. 5. An 8-inch diameter steel casing with welded or threaded joints will be lowered to the bottom of the boring and centered. The casing will be long enough to extend to the ground surface and will be seated using a hammer assembly. 6. A Portland cement/bentonite grout will be emplactxl from the bottom up in the aimulus around the casing using a tremmy pipe. The grout will be pumped into the boring until it displaces the drilling fluid and reaches the ground surface. 7. After the grout has set for at least 24 hours, tho (inlling fluid inside the casing will be circulated thoroughly with potable water until visible drilling fluids have been removed and clear water remains inside the casing. 8. Drilling equipment vrill be decontaminated and the drilling fluid will be replaced. If possible, water will be used instead of mud to drill the remainder of the boring. If mud is necessary, efforts will be made to minimize the amount of mud added to the drilUng fluid. 9. An 8-inch diameter boring will be advanced through the casing to the final well depth. Sampling vrill be performed as appropriate following procedures described in other sections of the RIWP. to 10. The remainder of the well construction methods will be the same as those used to construct , o single-cased monitoring wells as described in Section A2.5.1 of the RIWP. , '^ Figure 3-2 depicts typical double-cased monitoring well construction. Equipment . Q decontamination will be conducted as described in Section A2.4.2 of the RIWP. G:\W0RKA35241\RIWPA\SAP ADD.DOC HARDING LAWSON ASSOCIATES AD-5 AD2.5.2 Temporary Monitoring Well Construction Temporary groundwater monitoring wells will be installed follovring the methods described in Section A2.5.1 for single-cased monitoring wells. In general, the following procedures vrill be used unless field conditions require modifications: 1. Prior to set up, the drill rig and equipment will be decontaniinated by steam cleaning and/or a potable water wash as described in Section A2.4.2 of the SAP. 2. The driller will advance a 6.5-inch diameter boring to approximately 5 feet above the predicted water table depth using hollow-stem auger drilling techniques as described in Section A2.4.1. The approximate depth to the water table will be estimated before drilling activities begin based on groundwater elevations measured at nearby monitoring wells. 3. Beginning at this depth, the driller will collect soil samples using a split-spoon sampling device as described in Section A2.4.3. Split-spoon samples iwill be collected continuously until the water table is encountered. An HLA geologist will ,examine the soil samples to determine the level of the water table. 4. The driller vrill then advance the boring to between 5 and 6 feet below the water table. 5. The temporary monitoring well will be constructed of 2-inch diameter, schedule 40, flush- joint, threaded PVC with a 10-foot section of 0.020-inch factory-slotted screen. The PVC well will be lowered into the boring and suspended such that approximately 5 feet of screen is above and below the water table. If the boring is drilled with hollow-stem augers, the well will be constructed inside the augurs before they are removed. If the boring is drilled using rotary drilling techniques, the drilling tools will be removed before the well is constructed. 6. The boring vrill be allowed to collapse naturally around the well screen. If necessary, a small amount of filter sand will be poured into the boring to bring the bottom of the boring to the appropriate depth. If addition of sand is necessary, it vrill be poured slowly to avoid bridging. 7. Plastic sheeting will be taped securely aroimd the riser pipe approximately one foot above grade and spread out to form a skirt that extends radially at least 18 inches from the center of the well. The edges of the skirt vrill be covered and weighted prevent runoff from entering the well annulus. i 8. The temporary well vrill be capped with a locking, expandable plug. 9. If the well boring was advanced using mud rotary drilling techniques, the well will be developed by pumping and surging with potable water to rerhove the visible drilling fluid. If the well was installed using hollow-stem augers, no well development will be performed. Equipment decontamination will be conducted as described in Section A2.4.2 of the RIWP. If the decision is made to complete a temporary well as a permanent monitoring well, the 2-inch casing and screen will be removed, the boring will be reamed and the well constructed as described in Section A2.5 of the RIWP. If the well is not converted to a permanent monitoring well, the temporary well will be abandoned by removing the 2-inch casing and screen and backfilling the boring vrith powdered bentonite. \ AD2.6 Low Flow Purging and Groundwater Sampling groundwater monitoring wells will be purged and sampled using low-flow groundwater sampling procedures as described in EPA's Groundwater Issue (EPA, April 1996). Groundwater sampling procedures will generally follow the steps described in Section A2.8. Field documentation, sampling G:\WORK\3524I\RIWPA\SAP_ADD.DOC HARDING LAWSON ASSOCIATES AD-6 302221 preparation, and sampling apparatus decontamination procedures will be consistent with the RIWP. The low-flow groundwater sampling procedures are described below: BEFORE ENTERING THE HELD • Project objectives and quality assurance procedures, sampling locations, sampling procedures, preservation, packaging and shipping requirements, and analytical parameters will be reviewed with field personnel. • Previous water level measurements for each well, if available, vrill be reviewed before leaving for the site, and a summary of previous water level data will be taken to the field. • Health and safety procedures vrill be reviewed vrith all personnel. • A list of wells to be sampled and analyses to be performed will be prepared and transmitted to the laboratory. • All field equipment vrill be tested to ensure that it is operating properly. Because of the remote location of the site, duplicate instruments will be mobilized to limit down time due to possible equipment malfunction. • The laboratory will provide clean glassware required to collect the samples. The glassware will be cleaned in accordance with OSWER Directive 92540.0-05A. The glassware will include required preservatives and a list of which preservatives correspond to each analyte vrill be included vrith the glassware. The laboratory will provide sufficient glassware and/or samples for trip blanks, field blanks, and duplicate samples to be collected at the frequency described in the Quality Assurance Project Plan (QAPP) presented in Appendix C of the RIWP. IN THE FIELD 1. Sampling crews will receive labeled sample kits from the field manager and will confirm that the kits contain appropriate sample bottles, preservatives, filter pumps, ice, sample labels, chain-of-custody records, and well construction information. 2. Before purging or sampling each well, equipment vrill be decontaminated. Decontamination of pumps will include rinsing the pump and tubing with soapy water and deionized water before use. 3. The well number, date, pertinent observations (e.g., weather, well condition), casing diameter, screened interval, and field instrument identifications will be recorded on groundwater sampling forms (Appendix AA). 4. Monitoring instruments will be calibrated against known standards before making well measurements (generally calibrated once per day). Calibration vrill be recorded on field calibration data sheets as included in Appendix AA. 5. The well will be uncapped from the upwind direction and a photo-ionization detector (PID) or flame-ionization detector (FID) vrill be used to record relative organic vapor concentrations upwind from the well, at the top of the casing and within the well casing. Procedures for use of the FID or PID will be consistent with the manufacturer's manual, which may vary slighdy from model to model. The manual will be kept onsite at all times during equipment use. Q lo 6. Depth to water will be measured using an electronic interface probe. The probe will be to lowered into the well until a contact with the water surface is indicated by an electronic signal. lO t o G:\WORK\3524i\RlWPA\SAP ADD.DOC HARDING LAWSON ASSOCIATES AD-7 7. The tape will be marked or held at the measuring point. 8. The electric tape will be checked to ensure that it has not been cut by a sharp casing edge after it is placed in and removed from the well. 9. The depth to water will be measured to an accuracy of 0.01 foot 10. The probe will then be lowered below the groundwater and raised until the signal indicates that the probe is above the water table. The depth to water will be measured again as described in steps 7 through 9 above. 11. The groundwater elevation relative to mean sea level (MSL) will be determined by subtracting the depth to water from the surveyed top of casing elevation (measuring point). Measurements at each well will be taken at the marked survey point on the irmer casing and will be repeated until two consecutive measurements are obtained that agree within ±0.02 foot. Water level measurements will be recorded on water level measurement forms (Appendix /VA). Well identification, date, time, depth in feet to groundwater and remarks relevant to groundwater level measurements will be noted. Previous water level measurements for the well will be checked. If the difference between the current water level and the previous water level is greater than one foot, the water level vrill be remeasured. 12. The sample (pump intake) depth will be determined before sampling equipment is introduced into the well. In the wells in which the water level is above the top of the screen, the pump intake will be set at the middle of the screened interval. If the well is screened across the water table, the pump intake will be set at the mid-point between the groundwater level and the bottom of the well. 13. A field-decontaminated 2-inch diameter stainless steel submersible electrical sampling pump (Grunfos ' Redi-Flo II or equivalent) and dedicated 1/2-inch diameter Teflon -lined tubing will be used to purge and sample the well. To minimize excessive mixing of the standing water column in the riser with the water in the screened interval and to minimize the disturbance of solids which may have settled on the bottom, the pump and tubing will be carefully and slowly lowered to the pre-determined installation depth. 14. Depth to water will be measured after the pump has been installed to evaluate the effect of water displacement. Prior to purging, a final depth-to-water measurement vrill be recorded. At the start of purging, the flow rate will be monitored until a rate between 0.1 and 0.5 liters per minute (Lpm) is obtained. The flow rate will be measured using a volume-calibrated container and a watch. The water level will be monitored periodically as a guide to flow rate adjustment. Efforts will be made to keep drawdown to less than 0.1 meters (0.328 feet) during purging. If this minimal drawdown caimot be sustained, the water level will be monitored until a constant drawdown is achieved. 15. If drawdown does not stabilize at the minimum purge rate of 0.1 Lpm, the pump will be shut down periodically during purging to allow the well to recharge so that the water level does not fall below the pump during purging. 16. After the drawdown has stabilized, HLA will measure specific conductivity, temperature, pH, reduction/oxidation (Redox) potential, dissolved oxygen (DO), and turbidity approximately every five minutes. Field measurements will be performed as described in Section A4.0 of the SAP. 17. Purging will continue until the following five parameters measured in the field have stabilized for three successive readings. Readings will be considered stabilized based on the follovring criteria set forth by EPA [Groundwater Issue, April 1996): • Conductivity ± 3 percent • pH ±0.1 Standard Units G;\WORK\35241\RIWPA\SAP ADD.DOC HARDING l-AWSON ASSOCIATES AD-8 302223 Redox potential DO Turbidity ± 10 milhvolts, ± 10 percent ± 10 percent Temperature vrill be monitored but vrill not be used to establish stabilization. 18. Data on method and amount of water purged vrill be recorded on a groundwater sampling form (Appendix AA). 19. Water purged from the monitoring wells will be collected and stored at the site in properly labeled 55-gallon drums. The information specified on the drum label(s) will include, at a minimum, the date and well number(s) corresponding to the wells from which the water was removed. The water will be stored until final disposal arrangements are completed. 20. Sample collection will begin immediately after the five parameters noted above have stabilized. 21. During sample collection, the flow rate will remain the same as the established purge rate. 22. Except as noted in Step 24 and in Section A2.9, groundwater samples will be transferred direcdy from the pump discharge to the sample containers. VOC vials will be filled in a maimer that minimizes head space or air bubbles. Samples for VOC analyses will be collected first VOC sample vials will be filled to capacity and tightly capped to avoid retention of air bubbles. Remaining sample containers will be filled to approximately 90 percent of capacity. VOC sample containers will be preserved and filled according to EPA Region II CERCLA Quality Assurance Manual protocol (p. 31) as follows: • Collect three 40-milliliter vials of sample for VOC analysis. • Adjust the pH of one of the vials to less than 2 Standard Units by carefully adding 1:1 Hydrochloric acid (HCl) drop by drop to one of the filled 40-milliliter VOA vials. The number of drops of 1:1 HCl required will be recorded. The first vial may then be discarded. • Carefully add the same number of drops to the remaining two vials to be submitted for laboratory analysis. (The pH in the two vials for laboratory analysis should not be tested directly.) • Seal the vials. • The pH test is to be performed at each sampling location. • A fresh sample will be collected if an air bubble is detected in a VOC sample vial after sampUng is complete. 23. Non-VOC samples vrill be placed into prepreserved laboratory-prepared sample bottles. A small portion of the sample will be poured from the filled sample bottle into a second clean container. The pH of the sample material in the second container will be tested in the field to confirm that it falls vrithin the requirements of the QAPP. Additional preservative and sample material will be used to adjust the pH of the sample, if necessary. 24. Field-filtered samples will be obtained for analysis of metals where required. A 0.45-micron tj filter of compatible inert material will be used in filtering the samples. The filtering device o will be either an in-line filter or pressure filter apparatus. The filtering apparatus currently lo lo it^ planned for use on this project is the Gelman Sciences AquaPrep Flex Filter. The device • to uses a 10 mil PVC medical grade bag film with a Supor (inherently hydrophilic polysulfone) G;\WORKV3524l\RIWPA\SAP ADD.DOC HARDINQ LAWSON ASSOCIATES AD-9 membrane. The groundwater samples for field filtration will be transferred directly from the pump discharge line to the filter. 25. Preservation of samples to be analyzed for metals will be conducted after filtering. The filtered samples will be transferred directly from the filter apparatus to pre-preserved sample bottles. A small portion of the sample vrill then be poured out of the bottle for pH testing. If necessary, the pH of the sample will be adjusted by adding additional preservative. 26. Immediately after filling, samples will be placed in storage coolers on ice. Samples vrill be checked periodically with a thermometer to ensure preservation requirements are met. The temperature of the samples vrill also be recorded by the laboratory upon receipt. 27. Sample depth will be recorded, the groundwater sampling field data sheet will be completed and signed, and the chain-of-custody form will be signed. 28. The well cap vrill be closed and the well vrill be locked. Quality assurance/quality control (QA/QC) samples are discussed in the QAPP (Appendix C). AD2.7 Onsite VOC Analysis by Gas Chromatograph Groundwater samples will be handled and analyzed onsite using a portable GC as described below. 1. Groundwater samples will be collected as described in steps 2 through 21 of Section AD2.6. 2. 20 mLs of groundwater will be collected in a 40-mL vial. 3. The sample will then be agitated (shaken) for 2 minutes. 4. A dedicated syringe will then be inserted into the vial and a measured volume of gas from the sample vial headspace will be collected for analysis using the GC. The GC utilized will be a PID equipped vrith an 10.6 electron volt lamp. The chromatographic column will be a IO- meter capillary column of fused silica coated with the adsorptive material. The inner diameter of the capillary column will be 0.021 inches (0.53 mm). Precolumn backflush will use a 9-meter analytical column and a l-met«ir pn.H:olumn. Computing integrators will be used to plot the chromatogram for the detector inalysis and to compute and record the area of the chromatographic peaks. The peak areas will b« used to calculate concentrations for each of the compounds analyzed. The field QC procedures will be performed as set forth m tho QAPP addendum (Appendix CD). AD2.8 Aquifer Slug Testing Aquifer slug tests will be performed at select wells during lhe implementation of the RIWPA. One rising head test vrill be performed at the wells in which the water table intersects the screened interval. In wells in which the water level is above the top of the screened interval, a falling head and a rising head test will be performed. The tests will be conducted using a data logger and pressure transducers with chemically resistant cables. The data logger will be pre-programmed to collect incremental water level measurements using an approximately logarithmic time scale. Field decontamination procedures will be conducted as described in Section A2.4.2.2. The following procedures will be used during the slug tests: 1. Before beginning each test, the follovring information vrill be recorded: • Well internal diameter G:\WORK\3524i\RiWPA\SAP ADD.DOC HARDING LAWSON ASSOCIATES AD-10 302225 Location and elevation reference point from which water depth measurements are made Pre-test static water level (and elevation) of groundwater with respect to the reference point Date, time, and name(s) of persormel conducting test Well depth, screen depth and length, well radius, and depth, length, and radius of the gravel pack Volume or dimensions of slug Type of test (falling or rising head) Test number as recorded by the data logger Type of measuring device used 2. An initial depth-to-water measurement will be collected and recorded. 3. A decontaminated pressure transducer will be lowered into the well to a depth below the anticipated greatest depth of the slug. The water level will then be allowed to equilibrate. 4. The data logger will be initialized and set to the referenced water level 5. To initiate the falling head test, a decontaminated PVC or stainless steel slug vrill be completely introduced into the well as rapidly as possible while the data logger is started simultaneously. The slug will be of sufficient volume to displace a quantity of water that will require the well at least five minutes to equilibrate. 6. The falling head test will continue until the water level has returned to 90 percent of static. 7. Once the water level has returned to static, the rising head test can begin. The rising head test will be conducted by completely removing the slug from the well as rapidly as possible while simultaneously starting the data logger simult.inoously started. The rising head test will continue until the water level returns to at least 90 percent of static. 8. The data will be downloaded directly from the datalogger to a portable computer in the field. The data vrill be used for analysis (using AQTKSOLV®) of hydraulic conductivities using the Bower and Rice method. 9. If the data carmot be downloaded directly to a computer, the data vrill be printed in the field. A field geologist or engineer vrill keep detailed notes for each test. 302226 G:\WORK\35241\RIWPA\SAP ADD.DOC HARDING LAWSON ASSOniarPft Ar^ t* APPENDIX CD CONTENTS CDl INTRODUCTION 1 CD2 ONSITE ANALYSIS USING THE GC 1 CD3 LABORATORY ANALYTICAL PARAMETERS AND METHODS 3 CD3.1 Co-located Groundwater Samples 3 CD3.2 Soil Samples 3 302227 Section CD Revision 2 January 20,1997 CDl INTRODUCTION This Addendum to the Quality Assurance Project Plan (QAPP, HLA 1994) has been prepared by Harding Lawson Associates (HLA) on behalf of Island Chemical Company, Inc. (ICC). This QAPP Addendum has been prepared as an Appendix to the EPA-approved Remedial Investigation Work Plan (RIWP). This Addendum to the QAPP will be included in the RIWP as Appendix CD. The RIWP Addendum (RIWPA) includes the follovring analytical activities which were not specified in the original EPA-approved RIWP, and therefore not included in the original QAPP: • Onsite analysis of toluene, ethylbenzene and xylenes (TEX) in groundwater samples using a portable gas chromatograph (GC) • Laboratory analysis of undisturbed soil samples for grain size, moisture, total organic carbon (TOC), and porosity • Laboratory analysis for soil sample nutrient profiles including analysis of alkalinity, ammonia, iron, sulfate, sulfide, nitrate, nitrite, pH, and ortho-phosphorus. Other procedures and quality assm-ance and quality control (QA/QC) protocols for activities planned during the implementation of the RIWP Addendum are discussed in the RIWP- Quality Assurance and Procedures Plan (QAPP, Appendix C). CD2 Onsite Analysis Using the GC Sample documentation will be consistent with that described the QAPP (Section 3.0), with the exception of a chain-of-custody form. The samples collected for onsite analysis vrill be logged in the field books, and analyzed immediately after collection. The following information will be recorded in the field book for each sample: Sample identification number Date and time of sample collection Sample location and depth Sampling techniques Sample type (media sampled) Container type Onsite calibration and maintenance records of the onsite GC will be maintained by the field GC operator. These records will be filed onsite and may be subject to a QA audit The onsite GC operator will maintain spare parts for equipment and will be capable of making minor repairs as needed. Calibration records will be maintained as follows: 1. The GC operator will maintain a calibration record that will be kept with the GC at all times. 2. A label will be affixed to the GC showing description, manufacturer, model numbers, date of last calibration, calibrator's signature and due date of next calibration (where 302228 Section CD Revision 2 January 20,1997 applicable). Reports and compensation or correction figures will be maintained with the instrument. 3. Written step-vrise calibration procedures will be available for each measurement instrument. The calibration procedures for the field GC are described below (Source: Vironex Field Anal5^cal Services): 1. GC operator will perform a two-point calibration using a 50-microgram per liter (ng/L) and a 500-(ig/L standard of target compounds (TEX). The 50 ng/L standard is prepared by filling a 40 milliliter (mL) vial with 20 mLs of deionized water and adding 5 microliters (p.L) of a 200 ng/mL standard solution of target compounds in methanol. The 500 ng/L standard is prepared by filling a 40 mL vial with 20 mLs of deionized water and adding 50 y.L of a 200 ng/mL standard solution of the target compounds in methanol. 2. Agitate (shake) standards for 2 minutes prior to analysis. 3. Calculate the response factor (RF) for each target compound for each calibration concentration prior to analyzing site samples. 4. Determine the average RF for each target compound. The RF for each compound must be within 80-120 percent of the average RF from the initial calibration. 5. Determine percent relative standard deviation (%RSD) for each target compound (the %RSD may not exceed 20 percent). The GC analysis QA/QC techniques and frequencies are summarized below: • Analyze an instrument blank (as described in Section C6.3.2) at the start and end of each day. • Analyze a method blank (as described in Section C6.3.2) at the beginning of each day and after any sample yielding high concentrations of one or more target compounds. • Analyze one standard after every 10 samples. • Analyze one duplicate sample for every 20 samples. • Analyze target compound standards 1) at the start of each day, or 2) when the GC operating conditions have changed, or 3) when the GC column tj^e is changed, or 4) when the RF of the daily mid-point calibration check is not within 85 percent to 115 percent of the average RF from the initial calibration. The onsite analysis using the GC will be conducted in accordance with EPA Method 602 Modified. The method detection limits (MDLs) for the target compounds are as follows: • Toluene 5 ng/L • Ethylbenzene 5 ng/L • Xylenes 5 nS^ The GC that will be used to perform the onsite analyses can estimate concentiations lower than those listed above. If detected concentiations are below the given MDL, the result will be qualified to indicate that the concentiation is estimated. G:Work\3524l\qapp.doc _ , Harding Lawson Assoctates 302229 Section CD Revision 2 January 20,1997 CD3 Laboratory Analytical Parameters and Methods Approved laboratories will analyze co-located groundwater samples and perform several analyses on soil samples. Analytical parameters and methods for groundwater samples analyses are described in Section CD3.1. Analytical parameters and methods for soil sample analyses are identified in Section CD3.2. C03.1 Co-located Groundwater Samples The co-located groundwater samples (split from groundwater samples analyzed onsite using the portable GC) will be submitted to a certified laboratory and analyzed for TCL VOCs as detailed in Section C5,0. Sample documentation, including a chain-of-custody form, will be performed in accordance vrith Section C3.0. CD3.2 Soil Samples Laboratory analytical parameters, methods, and method reporting limits to be used during the implementation of the RIWPA, which were not specified in Section C5.4, are as follows: Soil Analysis Nitrate Nitiite Sulfate Sulfide Iron (total) Alkalinity Ammonia Ortho Phosphorus Total Organic Carbon Moisture pH Grain Size Analysis Porosity HCU bacteria count Total plate bacteria count M e t h o d EPA Method 353.2 EPA Method 353.2 SW-846 Method 9036 SW-846 Metiiod 9030 EPA Method 6010 EPA Metiiod 310.1 EPA Metiiod 350.2 EPA Metiiod 365.1 SW-846 Metiiod 9060 Standard Methods 209 F SW-846 Metiiod 9045 C .Modified ASTM D-422 By ASTM D-2216 and D-854 Standard Metiiods 9215C M Standard Methods 9215C M Reporting Limit 0.5 mg/kg 0.5 mg/kg 100 mg/kg 0.2 mg/kg 10 mg/kg 10 mg/kg 2.5 mg/kg 0.5 mg/kg 100 mg/kg Not Applicable (M) Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable NOTES: m g ^ = milligrams per kilogram. The listed reporting limits are subject to a slight change based on moisture content. G;\wQrk\3524l\qapp.cioc 302230 Harding Lawson Associates DRAFT DISTRIBUTION Draft Remedial Investigation Work Plan Addendum Virgin Island Chemical Site SL Croix, U.S. Virgin Islands January 20, 1997 -A Copy No Copies 1-7: Copy: 8 (unbound): Copy 9: Copies 10 -12: Copies 13 - 15: Ms. Caroline Kwan United States Environmental Protection Agency Section n Emergency and Remedial Response Division 290 Broadway New York, New York 10007-1866 Ms. Carol Bums Office of Regional Counsel United States Environmental Protection Agency 290 Broadway New York, New York 10007-1866 Mr. Cecil Williams Mr. Syed Syedali Mr. Austin Moorehead Department of Planning and Natural Resources Division of Environmental Protection Bldg. I l l - Apt 14A Water Gut Homes -1118 Christainsted, St Croix U.S. Virgin Island 00820 5065 Sills, Cummis, Zuckerman, Radin, Tischman, Epstein & Gross One Riverfront Plaza Newark, New Jersey 07102-5400 Copies 16 -19: Quality Assurance/Quahty Control Reviewer Harding Lawson Associates Princetoii Junction, New Jersey Jason M. Schindler, P.G. Associate Hydrogeologist This document was prepared for the sole use of the ICC emd the regulatory agencies involved with the project, the only intended beneficiaries of our work. No other parties should rely on the informaUon contained herein without the prior written consent of HLA. EAN/JSV/jsv/dm/ean/js/ml G:\WORK\35241\Rdadd3nil.DOC 302231