USVI Public Records

Document text

SDMS Document 115556 TRANSMITTAL To: Ms. Caroline Kwan From: John Virgie Date: July 25, 1997 Subject: Revised Draft Remedial Investigation Work Plan - Phase III Virgin Island Chemical Site St. Croix, U.S. Virgin Islands Project Number: 35241.7.2 Enclosed is the original and seven copies of the subject document. As discussed during a July 24, 1997 telephone conversation between me and Caroline Kwan ofthe U.S. Environmental Protection Agency (EPA), the issue of collecting sediment samples in the Fairplain Gut, as recommended by the National Oceanic and Atmospheric Adminisfration, will be resolved during implementation of the Phase III site activities. As previously stated, during field reconnaissance activities conducted during the preliminary Phase III site activities, Harding Lawson Associates (HLA) observed that several of the surrounding wells, included in the offsite well survey, were constantiy pumping. HLA requested the well owners shut off these pumps simultaneously so non-pumping water levels could be measured. This request was not honored by all well owners. HLA made additional efforts to obtain water levels during low activity periods for the surrounding businesses (on weekends and early Monday mornings) to obtain as many non-pumping water levels as possible. This situation may complicate the interpretation of groundwater flow beneath the subject site. Accordingly, EPA's assistance with encouraging the owners to simultaneously shut off the surrounding pumps during upcoming water level measurement activities, would be appreciated. If you have any questions or require additional information, please call me at (609) 936-0700. cc: Disfribution Harding Lawson Associates s Engineering and Environmental Services Z : ^ _ ^ 1 14 Washington Road, Building 7 ' ~ ' Princeton Junction, NewJersey 08550 - (609) 936-0700 -Fax (609) 936-1020 302292 Draft Remedial Investigation Work Plan Addendum - Phase ill Virgin island Chemical Site St. Croix, U. S. Virgin Islands Prepared for Island Chemical Company HLA Project No. 35241 7.2 DRAFT John S. Virgie, P.G. Senior Geologist DRAFT Edward A. Nemecek, R.G., CPG Principal Hydrogeologist Regional Geosciences Manager July 25, 1997 Harding Lawson Associates s = s = . « Engineering and Environmental Services 14 Washington Road, Building 7 Princeton Junction, NJ 08550 - (609) 936-0700 302293 DRAFT CONTENTS 1.0 BACKGROUND 1 1.1 Infroduction 1 • 1.2 Site Description... 1 1.2.1 Site Location 1 1.2.2 Site Sfructures 1 1.2.3 Site Setting 1 1.3 Previous Activities and Data Needs 2 1.4 Objective 3 2.0 WORK PLAN TASKS 5 2.1 AST Area Investigation 5 2.1.1 Soils 5 2.1.2 Groundwater 5 2.2 Former Drum Area Investigation 6 2.2.1 SoUs 6 2.2.2 Groimdwater 6 2.3 Onsite Storm Drain Sediment and SoU Sampling 6 2.4 Offsite River Gut and Bethlehem Gut Sampling 6 2.5 Groundwater Sampling 7 2.6 Evaluation of Groundwater Flow Direction and Aquifer Characteristics 7 2.7 Data Validation 7 2.8 Data Evaluation and Reporting 7 2.9 Meetings, Progress Reports, and Presentations to EPA 8 2.10 Management and Disposal of Investigation-Derived Wastes 8 3.0 SUPPLEMENTAL REMEDLU. INVESTIGATION TASKS 9 3.1 Field Sampling Program 9 3.1.1 Soil and Groundwater Investigation at AST Area 9 3.1.2 Site-Wide Groimdwater Quality Samphng 13 3.1.3 Onsite Groundwater Elevation Monitoring 13 3.1.4 Evaluate Groundwater Flow Dfrection In Deep Water-Bearing Zone 14 3.1.5 Onsite Storm Drain Sediment and Soil Samphng 14 3.1.6 Offsite River and Bethlehem Gut SampUng 15 o 3.2 Data VaUdation 16 to lo u> 3.3 Data Evaluation 17 >t» F:\3524i\WP\WORKPLA.N.DOC Harding Lawson Associates i DRAFT 3.4 Update/Track ARARs 17 3.5 Project Meetings and Reporting 17 3.5.1 Meetings witia EPA 17 3.5.2 Monthly Progress Reports 17 3.6 Management of Investigation-Derived Waste 18 4.0 ANTiaPATED SCHEDULE 19 TABLES 1 Summaiy of Proposed Samples FIGURES 1-1 Site Location Map 1-2 Location of Monitoring and Production WeU and Preliminary Assessment Soil Boring 1-3 Regional Geologic Map 2-1 Flow Chart 3-1 Proposed Sampling Locations - AST Area 3-2 Double-Cased Monitoring Well Construction Diagram 3-3 Approximate Location of Offsite Production WeUs 3-4 Proposed Sampling Locations - Onsite and River Gut 3-5 Proposed Sampling Locations - River and Bethlehem Guts APPENDIXES A CONTAINERS, PRESERVATION, PACKAGING, AND SHIPPING REQUIREMENTS B FIELD SAMPLUSTG PLAN ADDENDUM C QUALITY ASSURANCE PROJECT PLAN ADDENT3UM DISTRIBUTION 302295 F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates DRAFT 1.0 BACKGROUND 1.1 Introduction Harding Lawson Associates (HLA) has prepared this Remedial Investigation Work Plan Addendum on behalf of Island Chemical Corporation (ICC) as part of the Remedial Investigation (RI) of the Virgin Island Chemical site (site) located in St. Croix, U.S. Vfrgin Islands. This RI Work Plan Addendum is intended to address issues discussed and agreed to during the meetings on October 17, 1996 and May 12, 1997, with the U.S. Envfronmental Protection Agency, Region II (EPA) and comments presented in EPA's letter dated December 23, 1996. The work described in this document •wiU. be performed in accordance with the project Sampling and Analysis Plan (SAP), Health and Safety Plan (HASP), and Quality Assurance Project Plan (QAPP) provided with the Remedial Investigation Work Plan (Work Plan), dated March 17, 1994 and revised August 5, 1994 (HLA, 1994). Addenda to these documents are included as Appendixes. 1.2 Site Description 1.2.1 Site Location The site occupies approximately 3 acres in south cenfral 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 intennittent sfream 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 automobUe repafr 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 facUity is currentiy abandoned. The current layout of the facility is shown in Figure 1-2. Major onsite structures include the following: Laboratory and Warehouse Bmlding Maintenance BuUding Above-Ground 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 (fUled during previous work at this site) Generator Building Pump Bmlding 250,000-GaUon Ffre Water AST 1.2.3 Site Setting The site is located in a vaUey. 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. F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates U) o to to KO DRAFT The ground surface slopes gentiy across the site from southwest to northeast. Ground surface just beyond the northem and eastern fence Unes slopes steeply downward approximately 12 to 15 feet into the River Gut. An earthen berm, approximately 4 feet high, partially separates the AST farm in the westem part of the facUity from the remainder of the site. On the westem side of the berm, runoff drains from southwest to northeast. Surface drainage on the eastern portion of the site is confroUed by the buUdings, concrete paved areas, and two storm drains that channel runoff along the southeastern site boundary (Figure 1-2). Flow in the River Gut is intermittent and generally occurs only as a result of sufficient precipitation 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, shaUow soUs beneath the site consist of alluvium. The geology and hydrogeology of St. Croix were discussed in detaU in the Work Plan and in the Draft Data Summary Report (DSR), dated August 15, 1995 (HLA, 1995). Figure 1-3 presents a generaUzed 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 preUminary assessment and a drum removal action. In February 1991, NUS Corporation (NUS) collected groundwater, soU and sediment samples as part of a Preliminary Assessment^Site Investigation, performed on behalf of EPA. Data generated during these activities were summarized in the Remedial Investigation Work Plan (HLA, 1994). From October 1994 to August 1995, HLA implemented the EPA-approved Remedial Investigation Work Plan. ResiUts of work performed through August 1995 were smnmarized in the Data Summary Report (DSR) (HLA, 1995). The key findings of that investigation were: • Volatile organic compounds (VOCs) were detected in soils and shaUow groundwater samples collected at monitoring weU MW-1 in the vicinity of Tanks 8 and 9 in the above-grotmd storage tank (AST) area. • The two primary constituents of concem identified in previous investigations, pyridine and chloroform, were not detected in any soU or groundwater samples collected during HLA's 1995 investigation. • The visual reconnaissance performed after site clearing revealed no evidence of additional potential source areas. Followring EPA's review of the DSR, HLA prepared a proposal (April 12, 1996) and a draft Phase II RI Work Plan (May 15, 1996) to address the following as requested by EPA: Ui o • Obtain additional information on shallow groundwater flow dfrection(s) over time through the use to of automated water level recorders. .'^ • Characterize the extent of impacted soil and groundwater identified in the vicinity of Tanks 8 and 9 in the AST area. • Obtain groundwater quahty data near the center of the site (Former Process Pit Area) by installing and samphng monitoring weU MW-2 weU as originaUy proposed in the RI Work Plan (HLA, 1994). From May through August 1996, HLA implemented the EPA-approved Phase II RI Work Plan. ResiUts of the work performed during the completion of Phase II activities were summarized in the Draft F:\3524i\WP\WOFlKPLAN.DOC Harding Lawson Associates 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^ ofthe identified source area, but not to the west (offsite). The extent of VOCs in groundwater was not defined in a locaUy downgradient (westem) direction. • Chloroform was detected above the Federal Maximum Contaminant Level (MCL) in shallow groundwater in the vicinity of the former process pit area (Monitoring Well MW-2). • Based on several months of continuous groundwater level monitoring, a shallow groundwater divide frending north-south is interpreted to exist at the site. The groundwater flow dfrection across the majority of the site west of the divide is to the west and northwest, and the flow dfrection in the easternmost portion of the site east of the divide is to the east and northeast. On October 17, 1996 and May 12, 1997, EPA met with the respondents' and HLA to discuss the findings of the Supplemented Data Summary Report [HLA, 1996). EPA suggested that several data needs stiU remained and that they be addressed through supplemental investigative activities. HLA completed preliminary Phase in site assessment activities from June 9 through June 20, 1997. These activities were agreed upon at the May 12 meeting and documented in HLA's correspondence to EPA dated May 19, 1997. More work, as discussed below, is anticipated. Objectives ofthe Phase III RIWPA are discussed below. 1.4 Objective The objective of this phase (Phase III) of the RI is to address the following data needs identified during the October 17, 1996 and May 12, 1997 meetings with EPA, which EPA deems necessary for evaluation of remedial altematives justified by risk assessment. • Characterize the lateral and vertical extent (onsite and offsite) of toluene, ethylbenzene, and xylene (TEX) previously detected in soils and groundwater related to the small area near Tanks 8 and 9 in the AST area. • Evaluate background volatile and semi-volatile organic and metals concenfrations in onsite soils. • Estimate hydrogeologic properties (specifically hydraulic conductivity) of the shallow and deep water-bearing zones onsite. • Further evaluate the local flow direction(s) in the deeper portion of the water-bearing zone. • Install three deep monitoring wells ia the vicinity of MW-2, MW-6, and a thfrd location to be determined once the water level data from the preliminary assessment activities have been evaluated. EPA approval of the location of this well wUl be obtained prior to its installation. • Collect groundwater samples from all new and existing onsite monitoring and production wells to further evaluate the extent of Target Compound List (TCL) VOCs, semivolatile organic compounds (SVOCs), and Target Analyte List (TAL) metals, in groundwater. • Further evaluate the possible presence of TCL VOCs, SVOCs and TAL metals in soils in three additional location onsite and TCL SVOCs and TAL metals concenfrations in sediments in the River OJ o 1 At the meeting on October 17, 1996, EPA's contractor, CDM Federal Programs, disputed that the extent of VOCs in tO soils had been defined to the south of the presumed source area, because VOCs had been detected in samples from ' ^ 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 from 20 to 22 feet and 22 to 24 feet at SBB2 is attributed to capillary' ^ effects and/or fluctuating water levels associated with uiiderlying groundwater. F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates 3 DRAFT Further evaluate the possible presence of TCL VOCs, SVOCs and TAL metals in soils in three additional location onsite and TCL SVOCs and TAL metals concenfrations in sediments in the River and Bethlehem guts. Update and further evaluate baseUne ecological assessment information concerning potential ecological receptors and exposure pathways associated with the River Gut from the vicinity of the site to the confluence vwth the Bethlehem Gut. Preliminarily evaluate the potential applicabUity of soil vapor exfraction (SVE) and/or bioventing as possible remedial altematives for soil in the AST area. Obtain available water quaUty data which should be routinely coUected from the Fairplains Well Field supply wells from the Virgin Island Water and Power Authority. The tasks described in 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. 302299 F:\3524i\WF\WORKPLAN.DOC Harding Lawson Associates DRAFT 2.0 WORK PLAN TASKS Figure 2-1 presents a flow chart which summarizes the proposed tasks to be implemented to address the data needs identified in Section 1.4. The tasks are explained in detaU in Section 3.0. The tasks to be completed are as follows: 2.1 AST Area Investigation 2.1.1 Soils • InstaU soil borings offsite (west) of previous boring SBB17/MW-6 to assess the vertical and horizontal extent of toluene, ethylbenzene, and xylene (TEX) in soils associated with the AST source area in the vicinity of monitoring wells MW-1 and lvrW-6. • At the request of EPA, HLA installed four additional soU borings (SBAST 1 through SBAST 4, Figure 1-2) within the general AST area during preliminary Phase HI site assessment activities (conducted in June 1997). Analytical data from these borings will be evaluated to determine if additional soil borings are needed to assess additional impacts, if present in the AST area. The EPA wUl be contacted to discuss the locations of additional boring{s) in the AST area, tf needed. Data from previous soil boring SBEl, which was installed near the former concrete pad (Figure 3-1), will also be used in this evaluation. • PreliminarUy evaluate the apphcability of SVE and/or bioventing as remedial alternatives by coUecting and analyzing soil samples for analysis of grain size, moisture, total organic carbon, porosity, biological numeration, and nufrients. 2.1.2 Groundwater • Characterize the lateral extent of TEX in shallow groundwater offsite to the west of the AST area by collecting and analyzing groundwater samples in the field. Temporary wells will be installed at multiple locations. A single, offsite shallow monitoring well vuill be installed near the downgradient extent of the plume as determined by data collected from the temporary wells; access restrictions may limit the final weU location. • Characterize the vertical extent of TEX in groundwater beneath the AST source area by installing a double-cased monitoring well adjacent to monitoring well MW-6 (Figure 3-1). A pilot soU boring wiU be advanced to approximately 5 feet below the screened interval of MW-6 or at a confining urut, whichever is encountered first. No soil sampling will be performed in this boring (soil sampling was already performed in these areas during previous RI investigations). A steel casing wiU then be grouted in place at that depth to prevent cross-contamination during deeper drilling. After the grout has set for at least 24 hours, a pilot boring vidll be advanced through the grout. Depth-discrete Hydropunch® groundwater samples will then be collected at 10-foot intervals (starting at the interval 5 feet below the steel casing). When the targeted sample depth is reached, depth- discrete Hydropunch® groundwater samples will be collected and analyzed in the field for VOCs using the onsite field gas chromatograph (GC). Co-located samples (collected in 40 mL VOA vials with no headspace) will be obtained for laboratory analysis at a rate of one sample for every five screening samples, or more frequently as deemed necessary. The borings will be advanced either to the top of bedrock, to the maximum depth limitation of the sampling/drilling equipment that is available ( no deeper than 100 feet), or a depth where the field determined concenfrations of any individual chemical do not exceed MCLs, whichever is encountered first. The boring will then be advanced 10 feet below this depth, reamed to 8 inches in diameter and a 4-inch diameter ^ monitoring well with 10 feet of screen wiU be instaUed using the procedures outlined in the SAP. o to u> o o F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates DRAFT • If needed, and pending the resiUts of any additional soU investigations, shallow monitoring wells may be installed during a subsequent phase to evaluate the lateral and vertical extent of TCL VOCs, SVOCs, and TAL metals in shallow groundwater in the AST area. InstaUation of these weUs wUl be based on analytical results of soU samples collected from borings installed in the AST area during the preUminary Phase III assessment activities. 2.2 Former Drum Area Investigation 2.2.1 Soils • Three former drum areas were tentatively identified using the February 13, 1971 aerial photograph contauied in the U.S. Environmental Photographic Interpretation Center's document entitied Site/malysis; Island Chemical Company, St. Croix, Virgin Islands dated April 1987. At the request of EPA, three borings were installed onsite at the possible former location of 238 drums. Two borings were installed onsite at the possible former location of 64 drums. One boring was installed onsite at the possible former location of 8 drums. These borings were instaUed and sampled (Figure 1-2) during preliminary Phase III site assessment activities to evaluate the possible presence of additional source(s) within these former drum areas. Anal)^cal data from soU samples coUected from these borings wiU be evaluated to determine ff additional soil borings are needed to assess the additional source area(s) in the former drum areas, if present. The EPA •will be contacted to discuss the locations of additional boring(s) in the former drum areas, if needed. 2.2.2 Groundwater • If needed, additional monitoring well(s) may be instaUed to evaluate the lateral and vertical extent of TCL VOCs, SVOCs, and TAL metals in shaUow groundwater in the former drum areas. InstaUation of these wells wiU be based on anal}rtical results of soU samples coUected from borings instaUed in the former drum areas during the preliminary Phase III assessment and other soil borings which may be instaUed during a subsequent phase. 2.3 Onsite Storm Drain Sediment and Soil Sampling • CoUect seven sediment samples vnthin the onsite drainage system to characterize sediment within the onsite drainage system and two soil samples from each of the three onsite borings to be installed adjacent to the cenfral drainage system to characterize the soil beneath the cenfral storm drain (Figure 3-4). The sediment samples wiU be analyzed for TCL SVOCs, TAL metals, total organic carbon, particle grain size, pH, redox, percent moisture and conductivity, li the sediment is dry, pH and conductivity wiU not be measured. The soil samples wiU be analyzed for TCL VOCs, SVOCs and TAL metals. 2.4 Offsite River Gut and Bethlehem Gut Sampling • Secure access to collect samples from offsite locations in River Gut. CoUect two samples from each of the three borings in River Gut and fifteen sediment samples within the River Gut (Figure 3-4). Samphng in River Gut •will be conducted upsfream, across from, and downsfream of the site. These data wUl be evaluated with data from previous sampUng activities; access restrictions may limit the number of samples to be collected. The sediment samples •will be analyzed for TCL SVOCs, TAL metals, total organic carbon, particle grain size, pH, redox, percent moisture and conductivity. If the sediment is dry, pH and conductivity will not be measured. The samples from the borings will be analyzed for TCL VOCs, SVOCs and TAL metals. 302301 F:\3524iWT\WORKPLAN.DOC Harding Lawson Associates DRAFT waste material not already targeted by this investigation. A total of three sediment samples will be collected from the Bethlehem Gut starting at the confluence of the River and Bethlehem Guts. One sample wUl be coUected at the confluence with the River Gut, one sample wiU be coUected 500 feet upsfream from the confluence and one sample will be collected 1,000 feet upsfream from the confluence (Figure 3-3). The samples will be analyzed for TCL SVOCs, TAL metals, total organic carbon, particle grain size, pH, redox, and conductivity. If the sediment is dry, pH and conductivity will not be measured. • If needed, additional monitoring well(s) may be instaUed (outside of the River Gut) to evaluate the lateral and vertical extent of TCL VOCs, SVOCs, and TAL metals in shallow groundwater beneath the River Gut or Bethlehem Gut. Installation of these wells will be based on analytical results of soil samples from these guts dimng this phase and installed in the next phase, if needed. 2.5 Groundwater Sampling • Evaluate site-wide disfribution of TCL VOCs, SVOCs and TAL metals in groundwater by collecting groundwater samples from onsite and offsite wells including the newly installed shallow well(s), newly installed deep wells, shallow monitoring wells, and deep former production wells using low- flow purging techiuques. 2.6 Evaluation of Groundwater Flow Direction and Aquifer Characteristics • Perform downhole video surveys to evaluate the screen intervals and the integrity of onsite former production weUs Pi and P2. • Measure the water level in the new deep weUs and existing onsite and accessible offsite production/monitoring wells to evaluate flow direction in the deep portion of the water-bearing zone. A minimum of three rounds of water level measurements vdll be collected. HLA will attempt to obtain construction details and drUler or geologic logs of the onsite and offsite production/monitoring wells from sources on St. Croix. • Estimate the hydrogeologic properties of the shallow and deep water-bearing zones by performing slug tests at one onsite shallow monitoring well (MW-2) and one onsite deep monitoring well (MW- 2D) and by monitoring water level responses in nearby monitoring wells during development of the newly installed monitoring wells. 2.7 Data Validation • Conffrmation level laboratory data generated for investigative samples will be validated as discussed in the Work Plan. 2.8 Data Evaluation and Reporting • Interpret, evaluate and summarize the results of the proposed supplemental investigation, incorporate the results with previous investigations, and prepare a Supplemental Data Summary Report for submittal to the EPA. 2.9 Meetings, Progress Reports, and Presentations to EPA • One meeting with EPA will be requested following receipt, interpretation, and validation 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 report, whichever is ^ appropriate. At that time, the findings wiU be discussed along with the format for the final report. (o Additional meetings with EPA may be conducted as needed or upon request. Ui o to F:\3524i\vvp\WORKPLAN.DOC Harding Lawson Associates DRAFT 2.9 Meetings, Progress Reports, and Presentations to EPA • One meeting -with. EPA will be requested foUowing receipt, interpretation, and validation 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 report, whichever is appropriate. At that time, the findings wUl be discussed along virith the format for the final report. Additional meetings with EPA may be conducted as needed or upon request. • Monthly progress reports wUl continue to be submitted to EPA on the 15th day of each month (or first business day thereafter). The monthly progress reports will be prepared in accordance with the Adminisfrative Order on Consent and the Work Plan. 2.10 Management and Disposal of Investigation-Derived Wastes • Investigation-derived waste (IDW) will be managed in accordance with procedures outiined in Section 3.6 of this Work Plan. 302303 F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates DRAFT 3.0 SUPPLEMENTAL REMEDIAL INVESTIGATION TASKS The tasks to be completed during this phase of the RI are discussed below. Specifics of weU locations, weUs to be sampled, soil sample locations, analytical parameters, and other activities may be modified based on possible legal access restrictions, physical restrictions and on the findings of .various phases of each task. A summary of the proposed samples to be collected is presented in Table 1. EPA will be notified of any substantive changes. These changes, if necessary, wiU be discussed with and approved by EPA prior to implementation. Work will be conducted foUovraig the procedures outiined in the previously approved Work Plan and associated supporting documents. 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 secured the majority of offsite property access agreements necessary for this investigation. Prior to mobiUzation, ICC wUl make its best efforts to secure necessary property access to offsite sediment, soil and groundwater sampling locations described in this Work Plan. Prior to mobUization, HLA or the drilUng confractor vriU obtain the appropriate permits from the Vfrgin Island Department of Planning and Natural Resources to install the proposed monitoring wells. 3.1.1.2 Soil Sampling AST Area Soil sampUng wUl be performed to: • Characterize the lateral and vertical extent of TEX tn soU offsite and adjacent to Tanks 8 and 9 (westofborfrigSBBl7) • Assess the potential impacted areas in the general AST area • CoUect preliminary data regarding the applicabiUty of soil vapor exfraction and bioventing in the AST area as a possible remedial altematives Proposed boring locations are shovra on Figure 3-1. Three soil borings wiU be instaUed approximately 20 feet west, west-northwest, and northwest of previous boring SBB17. Additional offsite borings may be instaUed based on photoionization detector (PID) field screening results and field observations. Four borings (SBAST-1 through SBAST-4) were instaUed and sampled onsite during the preUminary Phase ni site assessment activities conducted in June 1997. These borings were located within the AST area (Figure 1-2) north and south of the previously defined impacted area. Analytical data from soU samples collected from these borings vwU be evaluated to determine if additional sampling is necessary to assess the extent of impact in the AST area. The EPA will be contacted to discuss the locations of additional boring(s) in the AST area, if needed. The results from soil boring SBE-1 (instaUed during Phase I activities adjacent to former Tank 20) wUl be used in conjunction with data from the four new borings to evaluate the general AST area (no PID readings were measured and no VOCs were detected above the detection limit in soil samples collected from the boring installed at this location). w o to Soil sampling vnU. follow the detaUed procedures described in the EPA-approved Work Plan and , co supporting docmnents and which have been implemented by HLA in previous phases of this RI. At , ^ F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates DRAFT each boring, soil samples wrill be collected continuously from groimd surface to the water table using a split-spoon. Upon opening the split-spoon, the sample -will be physically scored and screened for the presence of organic vapors using a PID. A sample from each 2-foot interval will then be immediately placed into a laboratory-prepared container sealed and stored in a cooler. Additional sample volume from each interval if avaUable, vnU 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 will be implemented as described in the Work Plan. Two soil samples from each boring v\all be analyzed: one from dfrectiy above the water table and one from the sample interval with the highest PID reading. If no PID readings are observed, sample intervals wiU be based on lithology as described in the RI Work Plan. Soil samples will be analyzed for TCL VOCs. Shelby tube samples -will be collected from two of the onsite borings for analysis of grain size, moisture, total organic carbon (TOC), and porosity to preliminarily evaluate the appUcabiUty of SVE as a remedial altemative for soU in the AST area. These samples will be collected using 3-inch outside diameter Shelby tubes. The Shelby tubes wUl be constructed of stainless steel tubing or equivalent materials. 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 the tube (typically 2 feet). The advancement of the Shelby Tube is performed smoothly and steadUy by the application of hydraulic pressure from the drill rig to the drilling rod cormected to the Shelby tube. The Shelby tube is exfracted using the same mechanisms operated in reverse. Storage, shipping and handling of these samples is described in the revised draft SAP. The analysis of the Shelby tube soil samples will be performed by Raytheon Envfronmental Services Laboratory located in Boothwyn, Permsylvania. Two soil samples wall be coUected from two separate onsite soil borings for analysis of total heterofrophic plate count and a hydrocarbon utilizer (HCU) bacteria count to preUminarily evaluate the appUcabUity of bioventing as a remedial alternative for soil in the AST area. These two soil samples wUl also be submitted for analysis to evaluate the available nutrient levels. The nutrient profile wUl include analysis of TOC, alkalinity, fron, ammonia, sulfate, sulfide, nifrate, nitrite, pH, and ortho phosphorus. One of the soil sampling locations for the bacteria counts vnll be collected from a soil sampUng 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 heterofrophic plate count and an HCU bacteria coimt samples will be performed by HLA, ff approved by EPA. Former Drum Areas Three former drum areas were tentatively identified using the February 13, 1971 aerial photograph contained in the U.S. Envfronmental Photographic Interpretation Center's document entitied Site Analysis; Island Chemical Company, St. Croix, Virgin Islands dated April 1987. At the request of EPA, three borings were installed onsite at the possible former location of 238 dmms. Two borings were installed onsite at the possible former location of 64 drums. One boring was installed onsite at the possible former location of 8 drums. These borings (Figure 1-2) were installed and sampled during preliminary phase III site assessment activities to evaluate the possible presence of additional source(s) within these former drum areas. Analytical data from soU samples coUected from these borings wiU be evaluated to determine if additional soU borings are needed to assess the former drum areas. The EPA will be contacted to discuss the locations of additional boring(s) in the former drum areas, ii needed. 302305 F:\3524i\WF\WOKKPLAN.DOC Harding Lawson Associates 10 DRAFT Background Areas Three background samples (Figure 3-4) vdU be collected from areas on the site that have not been impacted by site operations to evaluate the background concenfrations of metals in onsite soU. These samples vwU be coUected from the O-to-6-inch depth interval and will be analyzed for TCL VOCs, TCL SVOCs, and TAL metals. 3.1.1.3 Shallow Groundwater Investigation AST Area The purpose of this task is to characterize determine the areal extent of the dissolved TEX in groundwater, where the TEX concenfrations exceed their respective MCL. Groimdwater samples •will be coUected at the water table at three off-site locations (Figure 3-1) approximately 50 feet west, west- northwest, and northwest of MW-6 using temporary monitoring wells. The temporary monitoring wells wUl be constructed of 2-inch diameter PVC screen and riser as described in Section 2.5 of Appendix B. A 10-foot long screen wiU be positioned across the static water level. A 6.5-inch diameter boring for the temporary weUs wall be advanced using hoUow-stem auger driUing methods to a depth approximately 5 feet below the water table. The water table wtiU be located by evaluating split-spoon samples coUected from the borehole. The temporary weU wall be installed through the auger and the augers waU be removed. The water level measuring points wiU be marked and later surveyed to aUow for groundwater elevation calculations. An oU-water interface probe wall be used to measure static water levels and monitor for the presence of liquid phase hydrocarbons in each temporary well. Once the water level in the boring has remained constant for at least 45 minutes, a Teflon® bailer wall be lowered into the well to retrieve a groundwater sample which wall be fransferred to laboratory-cleaned 40-mL glass vials. The groundwater sample wall be analyzed onsite as soon as possible using a portable GC calibrated for TEX. The data coUected through field GC screening wdU be classified as screening level data. Further investigation, if necessary, wall be guided by the results of the onsite GC analysis of groundwater samples from the three temporary wells, ff TEX concenfrations exceed their respective MCLs, additional temporary weUs woU be installed and sampled using the above procedures at incremental 50-foot radial locations (i.e., approximately 100 feet from MW-6). If the results of aU three of the ffrst groundwater samples collected from the initial temporary well are below MCLs, then a 4-inch diameter monitoring well wall be installed at the furthest downgradient or westem location. The well waU be installed and developed as described in the RIWP. The weU screen wdU 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 wall be placed in 55-gaUon drums and staged onsite pending disposal or stolen. A minimum of three rounds of water level measurements waU be coUected from these weUs as part of the site-wade groundwater monitoring program.. The temporary wells wall be removed wdthin 2 weeks after thefr instaUation. The PVC screen and riser wall be exfracted and the borings will be abandoned as described in the RIWP. Former Drum Areas If needed, monitoring well(s) will be instaUed to evaluate the lateral and vertical extent of TCL VOCs, SVOCs, and/or TAL metals in shaUow groundwater in the former drum areas. InstaUation of these weUs wiU be based on analjrtical results of soil samples collected from borings installed in the former drum areas during the preliminary Phase HI assessment activities. The EPA wall be contacted to discuss the locations of monitoring weU(s) in the former drum areas, if needed. ( j j o to to o F:\3524i\WF\WORKPLAN.DOC Harding Lawson Associates 11 DRAFT 3.1.1.4 Onsite Deep Groundwater Investigation The vertical extent of TCL VOCs in groundwater onsite wall be evaluated by installation of double- cased monitoring wells to be located near MW-2, MW-6 and a third location to be determined once the water level data from the preliminary assessment activities can be evaluated. EPA approval of the location of this weU will be obtained prior to its' instaUation. A pilot soU boring wall be advanced to approximately 5 feet below the screened interval of the adjacent monitoring weU or at a confining unit, whichever is encountered first. No soil sampling will be performed in these borings (soil sampling was afready performed in these areas during previous RI investigations). A steel casing wdU then be grouted in place at that depth to reduce the potential for cross-contamination during deeper driUing. The steel casiag wall be installed as foUows. The pilot boring will be reamed to a diameter of 12-inches to the designated depth using auger or mud rotary driUing techniques, as dictated by field conditions. An 8-inch diameter steel casing with welded joints wall then be lowered to the bottom of the boring and centered. Cement grout will then be emplaced in the aimular space around the casing via a fremie pipe from the bottom up. The drilUng fluid tn the aimular space will be displaced by the grout, the drilUng equipment wall be decontaminated and the driUing fluid inside the casing will be cfrculated thoroughly with potable water until visible drilling 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 wUl be advanced through the grout. Depth- discrete Hydropunch® samples wiU be collected at 10-foot intervals (starting at the interval 5 feet below the steel casing). The Hydropunch® sampler is a speciaUzed tool designed to obtain groundwater samples wdthin the saturated zone without the installation of a monitoring weU. It is constmcted of stainless steel and Teflon with viton O-rings. The Hydropunch® sampler is designed to be driven by the sUde hammer commorUy used for obtaining spht-spoon samples. The Hydropunch® sampler wiU be removed from the boring between each sampUng uiterval and decontaminated using procedures described in the SAP. When the targeted sample depth is reached, the Hydropunch® sampler is opened by pulling 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 formation. After aUowing sufficient time for groundwater to fill the sample chamber, a Teflon bailer woU be lowered into the borehole to retrieve a groundwater sample which wiU be fransferred to laboratory-prepared 40-mL glass vials. These samples will be analyzed for VOCs using the onsite field GC. Co-located confirmation samples (collected in 40 mL VOA vials with no headspace) will be obtained for laboratory analysis at a rate of one confirmation sample for every five screening samples. Samples will be analyzed for TCL VOCs by CLP methodology. These confirmation samples wiU be preserved and handled as described in Section A2.8 of the RIWP. The borings wall be advanced either to the top of bedrock, to the maximum depth limitation of the sampling/driUing equipment that is available (no deeper than 100 feet), or a depth where concenfrations of any individual chemical do not exceed MCLs, whichever is encountered ffrst. The boring wall then be advanced 10 feet below this depth, reamed to 8 inches in diameter and a 4-inch diameter monitoring well wath a 10-foot screen wiU be installed, using the procedures outhned in the SAP. A diagram of the proposed double-cased weU is provided as Figure 3-2. Automated water level devices (e.g., TUBERs or equivalent) will be instaUed in each of the newly instaUed deep monitoring weUs. 3.1.1.5 Aquifer Testing Prelfrninary information on the hydrogeologic properties of the shallow and deep portions of the w^ater-bearing zone wall be obtained by conducting the foUowong activities. During development of the newly instaUed weUs, water levels wriU be continuously monitored in the well being developed and in the nearest wells using an automated data logger-pressure fransducer system. This wiU 302307 F:\3524i\VVF\WORKPLAN.DOC Harding Lawson Associates 12 DRAFT provide information regarding possible hydraulic communication between the shallow and deep portions of the water-bearing zone. Monitoring of recovery of water levels in selected onsite wells after development will also provide information on relative hydraulic conductivity between the upper and lower portions of the aqinfer. Slug tests will also be performed at one onsite shallow monitoring well and one deep monitoring well to supplement the data collected during well development. 3.1.1.6 Survey The location and elevation of the temporary wells, soU borings and new wells will be surveyed as specified in the Work Plan. The horizontal and vertical position will be surveyed with respect to the Puerto RicanA^frgtn Islands plane coordinate system (North American Datum of 1983, or NAD 83) to the nearest tenth of a foot The well locations wdU be converted from plane coordinates to latitude and longitude. The vertical position of the temporary weUs, soU borings, and new wells wiU be surveyed with respect to Mean Sea Level (MSL) to the nearest hundredth of a foot. Well elevations to be surveyed include the top of inner casing, top of outer casing, and adjacent ground surface. The location of the irmer casing elevation measurement wiU 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 soil borings wdU also be surveyed. 3.1.2 Site-Wide Groundwater Quality Sampling After installation and development of the new wells in the AST area, groundwater samples wall be coUected from the onsite and offsite monitoring weUs and the deep production weUs (P-1 and P-2). The site-wdde groundwater sampling wall be conducted to further evaluate groundwater quaUty at the site. Specifically, objectives of the site-wide groundwater sampUng 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 will be conducted approximately 2 weeks after instaUation and development of the new wells. HLA wall supply precipitation data for the two-week period prior to groundwater samphng activities are implemented. At the request of EPA, low-flow (minimal drawdown) groundwater sampling procedures (as described in Puis and Barcelona, 1995) will be utilized in lieu of the procedures described in the Work Plan. A 2-inch diameter Grundfos® Redi Flo 2 submersible sampling pump or a bladder pump will be utUized for purging and sampling. As recommended by Puis and Barcelona (1995), HLA will purge and sample using a flow rate not to exceed 0.5 titers per minute. Water quaUty probes wiU be used to measure key indicator parameters (temperature, pH, specffic conductance, redox, dissolved oxygen, and turbidity) during purging. After stabihzation of the water quality indicator parameters, groundwater samples wall be coUected dfrectiy from the pump discharge line. Sample containers, preservation, shipping, and chain-of-custody procedures will be implemented as described in the Work Plan. Groundwater samples wiU be analyzed for TCL VOCs, TCL SVOCs, and TAL metals using CLP protocols. As requested by EPA, local precipitation records for the two-week period prior to each groundwater sampling event will be submitted wath the groundwater anal}rtical data. 3.1.3 Onsite Groundwater Elevation Monitoring Groundwater elevations have been monitored at the site using automatic water level recorders (TUBERs) fristaUed at MW-1 and MW-3 in August 1995 and at MW-4 and MW-5 in April 1996. Four recorders are currentiy installed. The most recent data (since June 1997) wall be dowrnloaded from these recorders during the upcoming field program. These data wiU be combined with water levels which wdU be measured manually from all wells prior to the site-wide groundwater sampling event A minimum of three rounds of water levels measurements wiU be conducted. Groundwater contour o maps wall be prepared for selected dates using the water table elevations calculated from the manual ^ and automated measurements. o 00 F:\3524l\WF\WORKPLAN.DOC Harding Lawson Associates 13 CO o to IO DRAFT 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 Islands 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 will utilize these data in conjunction with information obtained from the onsite and offsite deep wells, as described below, to estimate the regional flow dfrection of the deeper portion of the water-bearing zone. 3.1.4.1 Onsite Deep Wells The onsite deep production weUs (P-l and P-2) will be evaluated using a video television camera to assess well integrity and screen intervals. After the survey, water levels(minimum of three rounds) will be measured at P-1 and P-2 a minimum of three rounds as part of the site-wide monitoring program. These data wall be combined wath water level data from the new onsite deep wells to assess onsite flow dfrection in portions of the deep water-bearing zone. 3.1.4.2 Offsite Deep Wells The purpose of this task is to measure groundwater levels in the offsite production wells 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 was field verified during the prehminary Phase III assessment activities. The locations have been plotted based on existing records and aerial photograph review. The offsite production wells from which water level measurements wall be coUected include (see Figure 3-3): Former WAPA well dfrectiy south of site WeU at Charlie's Concrete Company (east of site) Well at Meridian Engineering (northwest of site) Vfrgin Islands Port Authority (VIPA) WeUs 1 and 2 (west of site) U.S. Geological Survey wells downsfream of the site near confluence with Bethlehem Gut WeU at Carr's. Well at Zenon Construction CC has secured access agreements for the above wells. Prior to mobilization for the field sampling program, HLA woU attempt to obtain relevant information regarding the constmction, usage, and status of these wells. Groundwater levels wall then be measured at the wells using the procedures outiined in the Work Plan. The groundwater elevations calculated from the offsite and onsite deep weUs wiU be used to evaluate flow direction in the deep portion of the water-bearing zone. Water level contour map(s) wall be prepared. 3.1.5 Onsite Storm Drain Sediment and Soil Sampling 3.1.5.1 Sediment Sampling Samples of sediments wiU be coUected at onsite locations showoa in Figure 3-4. Sediment samples SDCSDl through SDCSD5 will be coUected from the cenfral storm drain system, ii present. Samples SDSSDl and SDSSD2 wiU be collected from sediments, ii present, in the southern storm drain system. These samples will only be collected if sufficient material exists for anal)rtical purposes. The locations may be modified in the field to nearby depositional areas where adequate sediment volumes are available. Sample SDCSDl will be collected from the storm drain at a point approximately 25 feet below the process area. Sample SDCSD2 will be coUected from the junction of the lines forming the 302309 F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates 14 DRAFT 3.1.5.2 Soil Sampling As requested by the EPA, one boring was to be instaUed at the approximate location where elevated photoionization detector (PID) field screening results were detected during the excavation of the former cenfral storm drain constructed of 55-gallon drums attached end to end. Historical information and reports concerning the removal ofthe 55-gallon discharge line do not indicate the exact locations where elevated PID readings were detected. Therefore, three borings, spaced equal distance from each other ( approximately every 40 feet), wiU be installed along the discharge line from the edge ofthe concrete pad to the River Gut. Two soil samples from each boring wdU be analyzed: one from dfrectiy above the water table and one from the sample interval with the highest PID reading. If no PID readings are observed, sample intervals will be based on lithology as described in the RI Work Plan. Soil samples wall be analyzed for TCL VOCs, SVOCs and TAL metals. 3.1.6 Offsite River and Bethlehem Gut Sampling Samples SDRGlA through SDRGll will be collected from the River and Bethlehem Gut sfream chaimels (Figures 3-4 and 3-5). • Samples SDRGlA, SDRGlB, and SDRGlC wiU be selected in the field at locations upsfream of the abandoned raifroad bridge, and upsfream of drainage from the bulldozed area adjacent to the site 25 feet of each other in the River Gut. These samples wall be evaluated as background sediment samples. • Sample SDRGl wall be coUected approximately 100 feet upsfream of the site boundary in a depositional area of the sfream bed, just dowoisfream of the abandoned raUroad bridge. Sample SDRG2 wall be coUected from the northeastern sfream bank in an area of waste material observed in the fill. Sample location SDRG2 is located at a seep of pefroleum-like material, if still present (visually identified by HLA in 1995 during ecological investigation activities), in the fill material on the northern bank of the River Gut. • Sample SDRG3 wall be collected from the depositional areas of the sfream bed upsfream of the former lab drain discharge. • Sample SDRG4 wall be collected from the depositional areas of the sfream bed below the former lab drain. • Sample SDRG5 wiU be collected from the depositional areas of the sfream bed approximately 100 feet downsfream from SDRG4. • Sample SDRG6 will be collected in an area of waste material observed, if still present (visually identified by HLA in 1995 during ecological investigation activities), in the fill on the northeastern side of the River Gut bank. • Sample SDRG7 will be collected from the depositional areas of the River Gut sfream bed at a point approximately 50 feet upsfream of the discharge of the cenfral storm drain system. • Sample SDRG8 wall be collected from the depositional areas of the sfream bed at a point where the cenfral storm drain system from the site discharges to River Gut. CO • Sample SDRG9 will be collected from the depositional areas of sfream bed at the point where o southern storm drain system from the site discharges to River Gut. f^ F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates 15 DRAFT • Sample SDRG9A will be collected from the depositional areas of sfream bed at approximately 500 feet downsfream of sample SDRG9. • Sample SDRGl0 will be collected from sediment deposits on the upgradient side of the berm located in the River Gut channel near the site. • Sample SDRGll wiU be collected from sediment deposits on the upsfream side of the sheet piling installed in the River Gut sfream charmel, downsfream of the site. • Samples SDRG12 through SDRGl 7 will be reserved for collecting sediments from the portions of the River Gut bank adjacent to the Golden Grove Correctional Facility, Meridian Engineering, Virgin Islands Asphalt Products Company and Charlie's Concrete in areas of observed waste material not already targeted by this investigation. • Samples SDBGl through SDBG3 will be collected from the Bethlehem Gut starting at the confluence of the River and Bethlehem Guts. One sample wdU be collected at the confluence, one sample wUl be collected 500 feet upsfream from the confluence and one sample will be collected 1,000 feet upsfream from the confluence. The sediment samples will be analyzed for TCL SVOCs, TAL metals, total organic carbon, particle grain size, pH, redox, percent moisture and conductivity. Ph and conductivity wall not be measured ff the sediment is dry. If physical access is possible and health and safety considerations are not compromised, one boring wall be installed in the River Gut at each of the locations SBRG-1, SBRG-2, and SBRG-3 (Figure 3-4), as requested by the EPA. Two samples from each boring will he analyzed: one from directiy above the water table and one from the sample inter\'al with the highest PID reading. If no PID readings are observed, sample intervals wall be based on lithology as described in the RI Work Plan. River Gut samples wall be analyzed for TCL VOCs, SVOCs and TAL metals. Additional onsite and offsite borings may be installed based on PID field screening results and field observations. Additional samples in the vicinity of the samples collected from borings installed in the River Gut may be collected based on analytical results of the samples collected during this phase. If needed, additional monitoring weU(s) may be installed to evaluate the lateral and vertical extent of TCL VOCs, SVOCs, and TAL metals in shaUow groundwater beneath the River Gut. InstaUation of these wells wall be based on analytical results of River Gut samples collected from the borings during this phase and will be installed during the next phase, if needed. 3.2 Data Validation Confirmation level laboratory data generated for investigative samples wiU be vahdated as discussed in the Work Plan. 3.3 Data Evaluation The data generated during this phase of the RI will be evaluated in conjunction with the data previously generated and reported by HLA (1995, 1996). The data will be evaluated to gain further information on the following: • Onsite and offsite extent of TEX in soil and groundwater in AST Area • Existence of potential impacts in the AST and former drum areas 302311 F:\3524l\WP\WORKPLAN.DOC Harding Lawson Associates 16 DRAFT 3.3 Data Evaluation The data generated during this phase of the RI wall be evaluated in conjunction with the data previously generated and reported by HLA (1995, 1996). The data wall be evaluated to gain further information on the following: • Onsite and offsite extent of TEX in soU and groundwater in AST Area • Existence of potential impacts in the AST and former drum areas • Extent of dissolved TCL VOCs, SVOCs and TAL Metals in groundwater • Flow direction(s) in the shallow and deep portions of the water-bearing zone • Onsite sediment and River and Bethlehem gut sediment TCL SVOCs and TAL metals concenfrations • Onsite and offsite soil TCL VOC, SVOC, and TAL metals concenfrations near the site drainage system • Background soU TCL VOCs, TCL SVOCs and TAL metals concenfrations. • Potential applicabUity of SVE and bioventing as possible remedial altematives for soil in the AST area • Baseline ecological assessment information concerning potential ecological receptors and exposure pathways associated wath the River Gut from the vicinity of the site to the confluence wdth the Bethlehem Gut. 3.4 Update/Track ARARs The list of Applicable or Relevant and Appropriate Requirements (ARARs) wall continue to be 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 wall continue to be reviewed periodically to identify changes to the ARARs that have already been identified. 3.5 Project Meetings and Reporting 3.5.1 Meetings with EPA One meeting with EPA wall be requested followring 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 wall be discussed along with the format for the final report. Additional meetings with EPA may be conducted as needed or upon request 3.5.2 Monthly Progress Reports Monthly progress reports wiU continue to be submitted to EPA on the 15fh day of each month(or ffrst business day thereafter). The monthly progress reports wall be prepared in accordance wath the Adminisfrative Order on Consent and the Work Plan. to CO CO o to F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates 17 DRAFT 3.6 Management of investigation-Derived Waste Investigation-derived waste (IDW) wiU be managed in accordance wath procedures outiined in the Work Plan. 302313 F:\3524i\WP\WORKPLAN.DOC Harding Lawson Associates 18 DRAFT 4.0 ANTICIPATED SCHEDULE The foUowing is the anticipated schedule to implement the Phase III RI activities as described in this Work Plan. This schedule assumes that all necessary drilling and access permits wiU be secured prior to August 4,1997. The schedule has not been finaUzed with the drilling subconfractor, therefore the schedule is subject to change: ACTIVITY Implement Revised Phase III Work Plan -AST Area Investigation -Onsite Deep Groundwater Investigation -Onsite Storm Drain Sediment and Soil Samphng -Offsite River and Bethlehem Gut Sampling -Site-Wide Groundwater Quality Sampling -Contingency DATE August 4, 1997 - September 19, 1997 August 4 - August 15 August 18 - August 27 August 28 - September 3 September 4-September 5 September 8 - September 12 September 15 - September 19 F:\35241\VmWORKPLAN.DOC Harding Lawson Associates 302314 19 TABLES 302315 TABLE 1. SUMMARY OF PROPOSED SAMPLES REMEDIAL INVESTIGATION -PHASE 111 VIRGIN ISIJ\ND CHEMICAL SITE ST.CROIX, U.S. VIRGIN ISLANDS Location ASTArea AST Area AST Area Onsite Background ASTArea Onsite Onsite Onsiie ' River and Bethlehem Gu(_ Onsite Storm Drain System Onsiie Central Storm Drain River Gut N/A - Not applicable MW- Monitoring Well GW- Groundwater G:\work\35241\phaselll\wplb Sample Type Soii grat) Soil grab Shelby Tube soil Soii grab " ""GW"grab"~ GW Hydropunch GWgrab •"GWgratj' Sediment grab Sediment grab Boring Sample Boring Sample .doc No.of Borings/Moniloring Wells 3 • N/A N/A N/A 3 shailow temp.,1 shaiiow/ perm. 3 deep 3 deep perm. existing MWs(5) and prod wells (2) N/A N/A 3 yxxyyyy....xyy. .y... No. of Samples 8 2 3 3 4 10-ft intervals 3 7 • _ 2 4 "" 7 •~ " 6 ' " ' " 6 •-- —- —- Analysis TCL VOCs.SVOCs.TAL metals (HCU) bacteria count.TOC, alkalinify^ iron,ammonia.sulfale.nitrate, nitite.pH, ortho phosphorous grain size, moisture, total organic carbon (TOC), and porosity '"fcrV0Cs;'sV0CsJAL rnetals" TCL VOCs.SVOCs.TAL metals Onsite portable GC for VOCs; 20% lab confirmation samples TCL VOCs.SVOCs.TAL mefals TCL VOCs.SVOCs.TAL metals TCL SVOCs.TAL metals, TOC, pH. alkalinity conductivity, redox, percent moisture, particle grain size TCL SVOCs.TAL metals, TOC, pH. alkalinity conductivity, redox, percent moisture, particle grain size TCL VOCs.SVOCs.TAL metals TCL VOCs.SVOCs,TAL metals Ui o to U i FIGURES 302317 ^^^3>>. \-:X "^- \ - . \:-.::.*.-: .• ,\! 1 (rxyiyy'yyxm ,^:y v,..\ .r^L.-Ee:n - • fr^XiAF:v;.::XXXX.-- \MM^-\^5,?^ip^siobl .- \ - V ^ I /. U / . - - ' m •.... •-•• ) ... , v ' ' / - . v / r .• •• -f^ ..>•• > - ^ rs •>-, •'>^ s . - . ^ • -•"--.< -^ •. \—TV>-N\~^r^T-; •.' y > r i i s ^ • 'rx-'.^^i'-i^'. U--•'~~ iJii'''rT\Ptv^-^n VM^i^^rT^ ••^AMV \Ml:^^il^5|}^-i ^/i>4^^®^ SC'J.=,C-j u s : : l . l Wlnuts Cuod Wcp: C:-..-::i::r,:-.»<J, V.l. " FOR ILLUSTRATiOiM PURPOSES ONLY I .- - — I ~ Harding Lawson. Associates Engineering ond E.nvironmentol Services — : — . . ~ U l North ThircJ Sires: — - — • " "Z PhilacelDhlc. Pennsylvcnio 19105 ~ ' • — - 215-527-^505 DRAWN WGA JOB NUMBER 35241.5 SITE LOCATION MAP 3 02318 VIRGIN ISLAND CHEMICAL SITE St. Croix. U.S. Viroln IsloncJs FIGURE 1-1 APPROVED DRAWING NUMBER 35241 ADA DATE 11/5/95 REVISED DA MW-6 SBAST3 >- X o to X ii z UJ LEGEND PRELIMINARY ASSESSMENT SOIL BORING LOCATION MONITORING WELL LOCATION PRODUCTION WELL LOCATION STORMWATER INLET EXISTING ABOVEGROUND STORAGE TANK TANK PAD-FORMER ABOVEGROUND STORAGE TANK LOCATION SQUSCL. ADAPTED FROM SITE MAP, VI CHEMICAL. ST. CROIX, U.S.V.I BY NUS CORPORATION DOCUMENT 0 2 - 9 1 0 1 - 0 4 - 5 1 . UNDATED Hording Lawson Associates Engineering and Environmentol Services 14 .Woshington Rood Priricelon Juction, New Jersey 08550 60^936-0700 LOCATION OF MONITORING AND PRODUCTION WELLS AND PREUMINARY ASSESSMENT SOIL BORINGS VIRGIN ISUND CHEMICAL-SITE St. Croix, U.S. Virgin Islands Ui O to OJ M VO FIGURE 1-2 DRAWN JSW/WGA JOB NUMBER .^524 1,7 1? APPROVED DWG. No. OATE REVISED DATE 54' 5 2' 6 4'50' 4«' 4 6' 4 4' 64 • 40' 4 6 ' • n'4.r X c .1 R I B n /•: y x s>ir Rivcii csru»«t liii CRANDC PniHCCiSC C01D(N ROCi; CHBlStllkKSTlO ^ imk^^myyymymf^x'^ \^:y::Xs.\A, ".'.Vv .•"••.•."•'.v. Harding Lawson Associates Engineering ancjl Environmentol Services 131 Nortli Third Street Ph)IodelpJ)io, Pennsylvonio 19106 215-627-4505 DRAWN JOB NUMBER WGA 35241.5 REGIONAL GEOLOGICAL MAP VIRGIN ISLAND CHEMICAL SITE SL Croix, U.S. Virgin Isionds APPROVED DRAWING NUMBER FIGURE 1-3 DATE REVISED DATE • • Determine horizontal and vertical extent of affected soils offsite, related to the identified onsite source area associated with the AST form. Secure access to offsite property for soil boring and well installation Select Location for additional offsite boring radially outward from this location Collect soil samples from boring at selected location -Yes -Yes Evaluate Data Field screen samples for organic vapors using PID Submit two samples from each boring for laboratory analysis Access location(s) for additional offsite and onsite soil borings to define extent of impacted soil. Begin temporary well sampling program to assess horizontal extent of affected groundwater near AST area. / S o i l Sample Data collection t a s k \ I completed. Proceed to temporary W-No well sampling program. / Yes LO O to OJ H ; Ikifd^rK] iiiwson A:;:;()(:i()li:s I i :ii;uu;(':i!>", uiui ! \ iivif;jiiri;;[t'iil Soivu:!;:; '. I'l •.'/n.li'i'lliii. KIH;I1 ; f:t:r,:i.\uti ..•iirrliiai. N™ ..'i.rii-/ H K W ; litl'l 'I.M; ll/llll I !II«WW ,i()ll ;V!;M!!II. 11 OvV (;i!AK 1 yii«;!N !!;iAM) CHIMICAI SII!. SI. i'loix, li.S. Vliqiii IskiiK.';; .M'l'M'VI!) , Iill ,V,;4ljii)VVS!) ICIIKI I/AX! KIW.m NI). ri ri e SBAST2 + + SBB90 N^W'-e^sBBio " ^BB14 © SBBI11 SBB2^ MW-1 Qk SBBSe ^ 586120 ^ SBB(13 e mSBAST3 ri n^n n n n ri I -!l I 2l I i l I 2l I »l I - l I «l e-SBB6 SBB3 SBB7 0SBB5 ®SBB4 ®SBB16 LJ LJ LJ LJ LJ ® SBAST4 ABOVEGROUND TANK FARM LJ LJ SBEl © EARTHEN BERM ©SBB15 WALL RAMP 30 60 90 n. FOR ILLUSTRATION PURPOSES ONLY LEGEND • A PROPOSED TEMPORARY WELL LOCATION PROPOSED SOIL BORING LOCATION PROPOSED DEEP MONITORING WELL LOCATION © ( ) CID PREVIOUS SOIL BORING LOCATION MONITORING WELL LOCATION EXISTING ABOVEGROUND STORAGE TANK TANK PAD-FORMER ABOVEGROUND STORAGE TANK LOCATION zzesoe Hording Lawson Associates Engineering ond Environmentol Services 14 Woshington Rood Princeton Junction. New Jersey 08550 609-936-0700 DRAWN WGA JOB NUMBER 35241.5 PROPOSED SAMPLING LOCATIONS VIRGIN ISLAND CHEMICAL SITE St. Croix, U.S. Virgin Isionds FIGURE 3-1 APPROVED DRAWING NUMBER 35241A11 DATE 11/7/qfi REVISED DATE fi/7n/Q7 LOCKING PROTECTIVE CASING GROUND SURFACE A A A A / / / / / f C ! CEMENT CEMENT BENTONITE SLURRY 8" STEEL CASING RLTER PACK SAND 4" WELL SCREEN 8" BOREHOLE '.V.V. / 0 e Z \A A A A A A /• •/ GROUT 12" BOREHOLE BOTTOM OF SCREEN IN ADJACENT MONITORING WELL 4" WELL CASING BENTONITE SEAL (2 FEET MIN.) o OJ o to OJ to OJ Harding Lawson Associates Engineering ond Environmentol Services 14 Woshington Rood Princeton Juction, New Jersey 509-936-0700 DOUBLE-CASED MONITORING WELL CONSTRUCTION DIAGRAM VIRGIN ISLAND St. Croix, U.S. CHEMICAL SITE Virgin Islands FIGURE 3-2 DRAWN ETG/WGA JOS NUMBER 35241.5 APPROVED DRAWING NUMBER 35241A07 OATE 1 1 / 7 / 9 6 REVJSED DATE 7/21/97 GOLDEN GROVE ADULT CORRECTIONAL FAOUTY UNOEVaOPED ^ * * * * * , * . * * i'l All-*-*•,-*>, ,^.^.^AA_r*u*i_i^_^_A_ft- # EXPECTED LOCATION OF OFFSTE WEUS OJ o IO OJ to FOR ILLUSTRATION PURPOSES ONLY ZENON MJL Harding Lawson Associates Engineering ond Environmentol Services 14 Woshington Road Princeton Juction, New Jersey 08550 609>-936-0700 APPROXIMATE LOCATION OF OFFSITE PRODUCTION WELLS VIRGIN ISLAND CHEMICAL SITE St. Croix, U.S. Virgin Islands FIGURE 3-3 SDRG-2 LEGEND 0 A X o ^ - ^ yd ( ) I J PROPOSED SEDIMENT SAMPLE LOCATION PROPOSED BACKGROUND SOIL SAMPLE LOCATION PROPOSED SEDIMENT AND SOIL BORING LOCATION PROPOSED SOIL BORING LOCATION MONITORING WELL LOCATION PRODUCTION WELL LOCATION STORMWATER INLET EXISTING ABOVEGROUND STORAGE TANK TANK PAD-FORMER ABOVEGROUND STORAGE TANK LOCATION 240 ft. FOR ILLUSTRATION PURPOSES ONLY 2) SAMPLES SDBG-1 THROUGH SDBG-3 WILL BE COLLECTED FROM BETHLEHEM GUT EVERY 500 FEET UPSTREAM FROM CONFLUENCE WITH RIVER GUT (SEE FIGURE 3-5) SOURCE: SITE MAP, VI CHEMICAL, ST CROIX, U.S.VI. BY NUS CORPORATION DOCUMENT 02-9101-04-51 lltJOATFO ANO AERIAL PHOTOGRAPHS OJ O to OJ to on SDRG-10 SDRG-11 HarcJing Lawson Associates Engineering and Environmental Services 14 Wost^ington Rood Princeton Juction. New Jersey 08550 609-936-0700 PROPOSED SAMPLING LOCATIONS ONSITE AND RIVER GUT VIRGIN ISLAND CHEMICAL SITE St. Croix, U.S. Virgin Isionds FIGURE 3-4 AWN .Kin MCJURTD Annnj.MM LEGENn C2D SURFACE WATER = = = = = ROAO STREAM PROPOSED SEDIMENT SAMPLE LOCATION CARIBBEAN SEA OJ o to OJ to 1000 2000 3000 FOR ILLUSTRATION PURPOSES ONLY Harding Lawson Associates Engineering ond Environmentol Services 1 4 Washington Rood Princeton Jet., New Jersey 08550 609-936-0700 PROPOSED SAMPLING LOCATIONS RIVER AND BETHLEHEM GUT ISLAND CHEMICAL COMPANY i. ST CROIX, U.S. VIRGIN ISLANDS FIGURE 3-5 DRAWN I JOB NUMBER APPROVED APPENDIX A CONTAINERS, PRESERVATION, PACKAGING, AND SHIPPING REQUIREMENTS 302327 A p p e n d i x A. C o n t a i n e r s , P r e s e r v a t i o n , P a c k a g i n g , a n d Shipping R e q u i r e m e n t s Island C h e m i c a l C o m p a n y St. Croix, U.S. Virgin I s l a n d s DRAFT OJ o to OJ to 00 Aiialysis Containers PrGservation Technical Holding Time' Volume of Container Shipping Normal Packaging Groundwater Organic Analyses TCL VOCs Three 40-inl glass vials with Teflon septum-lined caps TCL SVOs Pyridine TCL Pesticides and PCBs Two 1-liter amber glass bottles with Tenon^*^-lined caps Two 1-liter amber glass bottles with Teflon^'^-lined cups Two 1-liter amber glass bottles with Teflon "^-lined caps 1:1 MCI topH <2, cool to 4°C in dark storage Cool to 4°C in dark storage Cool to 4''C in dork storage Cool to 4°C, Na^SzOa Groundwater Inorganic Analyses TAL metals One 1-liter polyethylene HNOg to pH <2,0 (unfiltered) bottle 14 days Extract within 7 days, analyze within 40 days after extraction Extract within 7 days, analyze within 40 days after extraction Extract within 7 days, analyze within 40 days after extraction 6 months, except Hg • 20 days Cyanide One 1-liter polyethylene bottle N a O H t o p H > 1 2 , 14 days cool lo 4°C Fill completely, no air bubbles Fill 90% full Fill 90% full Fill 90% Fill 90% TAL metals One 1-liter polyethylene HNO3lopH<2.0 6 months, except Hg - Fill 90% (filtered] bottle 28 days 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 Soil Organic Analyses TCL VOCs One 120-ml vial with Teflon™-septa lined lid Cool to 4°C in dark 10 days storage Fill completely rCL SVOs Two 16-oz. amber glass jars Cool to 4°C in dark Extract within 7 days Fill 90% and Pyridine with Teflon -lined lid storage and analyze within 40 days after extraction 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 Bubble pack Bubble pack Revised July 25, 1997 Appendix A. Containers, Preservation, Packaging, and Shipping Requirements Island Chemical Company St. Croix, U.S. Virgin Islands DRAFT Analysis Containers Preservation Technical Holding Time* Volmne of Container OJ O to OJ to VO TCL One 4-oz wide-mouth glass Cool to 4°C Pesticides jar with Teflon -lined lid and PCBs Soil Inorganic Analyses TAL Metals One 8-oz wide-mouth glass Cool to 4°C jar with Teflon™-lined lid Shipping Cyanide To be analyzed using material from metals sample Nitrate/Nitrit One 32-oz glass bottle* e Cool to 4''C Cool to 4''C Sulfate Sulfide One 32-OZ glass bottle* Cool to 4''C One 32-OZ glass bottle* Cool to 4°C Iron (total) One 8-oz wide-mouth glass Cool to 4°C jar with Tenon™-lined lid Alkalinity One 32-oz glass bottle* Cool to 4°C Ammonia One 32-oz glass bottle* Cool to 4°C Extract within 7 days and analyze within 40 days after extraction 6 months, except Hg • 28 days 14 days 28 days 28 days 7 days 6 months 14 days 28 days Fill 90% Fill 90% Fill 90% Fill go%> Fill 90% Fill 90%) Fill 90% 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 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 NonnnJ Packaging Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack Bubble pack "sviseH '••'•• 25, l l Appendix A. Containers, Preservation, Packaging, and Shipping Requirements Island Chemical Company St. Croix, U.S. Virgin Islands DRAFT Analysis Containers Preservation Teclinicol Holding Time* Volume of Container Shipping Normal Packaging Ortho One 32-oz glass bottle* phosphorus Cool lo 4°C 48-hours pH Total Organic Carbon One 32-OZ glass bottle Cool lo 4°C Shelby Tube Moisture Shelby Tube Grain size Shelby Tube Porosity Shelby Tube OJ o to OJ OJ o HCU bacteria Count Total plate bacteria count 500-ml Glass 500-ml Glass None None None None Cool to 4°C Cool to 4°C Fill 90% As soon as possible Fill 90% 28 days Fill 90% As soon as possible Fill 90% None Set None Set 24-hours or as soon as possible 24-hours or as soon as possible Fill 90% Fill 90% 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 collecdon 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 Bubble pack Revised July 25, 1997 T?.\if-<-i-4-i\i;irr*-rr\r»'-i r>r^/^ DRAFT OJ o to OJ OJ Notes: 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. Certificates of analysis verifying sample container cleanliness will be retained and available for review by USEPA, * There are no SW-846, Test Methods for Evaluating Solid Waste" protocols for nitrite, alkalinity, ammonia, or ortlio-phosphate. We have proposed using EPA Chemicui Analysis of Waters and Waste Methods, Because these methods were written for liquids, not solids, minor modifications will be required. Although nitrite can be analyzed by method SW 9200 we are not aware of any laboratories that still run this method. We propose analyzing nitrate similarly to nitrite. The following are brief descriptions of method modifications for each parameter: 1. Alkalinity-10 grams of sample aliquot is leached with 100 ml of DI water for 1 hour. Decant 50 ml of leachate. Titrate as prescribed in method. 2. Ammonia - Distill 2 grams of sample to a final volume of 100 ml. Analyze by colorimetric autoanalyzer as prescribed in method. 3. Nitrate - 10 grams of sample aliquot is leached with 100 ml of DI water for 1 hour. Analyze by colorimetric autoanalyzer as prescribed in method. 4. Nitrite -10 grams of sample aliquot is leached with 100 ml of DI water for 1 hour. Analyze by colorimetric autoanalyzer as prescribed in method, ortho-phosphate -10 grams of sample aliquot is leached with 100 ml of DI water for 1 hour. Analyze by colorimetric autoanalyzer as prescribed in method. ' The time of sample collection to extraction/analysis. G gram < less than HNOj nitric acid HCl hydrochloric acid oz. ounce ml milliliter VOCs volatile organic compounds SVOs semivolatile organic compounds > H2S04 NaOH TAL greater than sulfuric acid sodium hydroxide Target Analyte List °C Hg NajSjOg TCL degree Celsius mercury Sodium thiosulfate Target Compound List Z5. 1. APPENDIX B FIELD SAMPLING PLAN ADDENDUM 302332 DRAFT APPENDIX B CONTENTS 1.0 INTRODUCTION 1 2.0 FIELD INVESTIGATION PROGRAM 2 2.1 Stream Sediment Sampling 2 2.1.1 Sediment Sampling When Stream is Dry 2 2.1.2 Sediment Sampling When Stream is Flowing 2 2.2 Shelby Tube Soil Sample Collection 3 2.3 Hydxopmich® Groundwater Sampling 4 2.4 Mud Rotary DriUing Methods 5 2.5 Monitoring Well Installation 5 2.5.1 Double-Cased Well Construction 6 2.5.2 Temporary Monitoring Well Construction 7 2.6 Low Flow Purging and Groundwater Sampling -. 8 2.7 Onsite VOC Analysis by Gas Chromatograph 11 2.8 Aquifer Slug Testing 12 302333 F:\3524iVWPVSAPP.DOC Harding Lawson Associates i DRAFT 1.0 INTRODUCTION 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 RfWP Addendiun (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 undisturbed soil samples using a Shelby tube samphng 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 drilhng methods Installation of temporaiy monitoring wells Installation of double-cased monitoring wells Collection of groimdwater 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. 302334 F:\3524i\WRSAPP.DOC Harding Lawson Associates 1 DRAFT 2.0 FIELD INVESTIGATION PROGRAM Specific field procedures to perform the activities identified in Section 1.0 above are presented in this addendum. 2.1 Stream Sediment Sampling Efforts v^dll be made to coUect stream sediment samples when River Gut is not flowdng. Section 2.1.1, presents the samphng procedures to be followed if the stieam is dry. However, if it is necessary to coUect sediment samples when River Gut is flowing, HLA will follow the sampling procedures described in Section 2.1.2. 2.1.1 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 visuaUy to determine qualitatively the area of greatest sediment deposition. This area wiU be selected as the final sampling location. 3. A field-decontaminated, stainless steel hand auger will be used to collect the composite sediment sample from the 0-6-inch interval from three locations within the roughly 10 to 20 foot area described in step 1. The hand auger will be decontaminated before use follovnng the procedures specified in Section A2.4.2.2 of tiie RIWP. 4. The sediment samples wUl be placed directiy into a decontaminated stainless steel bowl, homogenized and transferred to laboratory-prepared sample containers. The sample containers will then be sealed, labeled as described in Section A2.10.1 of the RIWP, and placed directiy into a cooler •with ice (approximately 4°C). 5. The final sample location area wiU be marked and photographed to show its location with respect to fixed references. 6. • The distance from each samphng point wiU be measured wath respect to at least three fixed references and recorded to allow future relocation of the sample. 2.1.2 Sediment Sampling When Stream is Flowing If possible, sediment sampling will be postponed until the stieam is dry. If this is not practical, the stieam sediments will be sampled using the foUowing procedures: 1. Stream flow vdll be evaluated to detennine if the stieam can be entered safely. 2. Beginning at the furthest downstieam location, HLA persormel wall enter the stieam at a location downstieam of the proposed sampling location. AU sample locations wdU be approached from the dowmstieam direction to avoid disturbing upstieam sediments that might be carried to W dowmstieam locations not yet sampled. o N5 CO UJ F:\3524i\vmsAPP.DOC Harding Lawson Associates DRAFT 3. The proposed and final sample locations wdll be determined as described in Steps 1 and 2 of Section 2.1.1. 4. A field-decontaminated Eckman Dredge sampler wrill be used to collect the three sediment samples at each location to be combined as one composite sample. 5. The three sediment sample will be placed in a decontaminated stainless steel bowl, homogenized and tiansferred to laboratory-prepared sample containers. The sample containers will then be sealed, labeled as described in Section A2.10.1 of the RIWP, and placed directiy into a cooler wnth ice (approximately 4°C). 6. The sample location wdll be photographed and recorded as described in Steps 5 and 6 of Section 2.1.1. 2.2 Shelby Tube Soil Sample Collection Soil samples wrill be coUected from fine-grained material using a Shelby tube sampling device. The Shelby tubes wHl 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 wiU be fastened to a check value that helps hold the sample in place as it is being withdrawn. Field docvtmentation and equipment decontamination wdll be conducted as specified in the RIWP. The following procedures will be used to obtain imdisturbed soil samples using the Shelby tube: 1. The boring will be advanced to the top of the interval to be sampled. 2. The driU bit and drUUng rods will be removed from the boring and a field decontaminated Shelby tube sampler wUl attached to the driU rod assembly and lowered to the bottom of the boring. 3. The Shelby tube wdll then be pushed to the required depth, if possible. The Shelby tube wdU be advanced by the apphcation of hydrauhc pressure from the drill rig to the driU 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 wdthin the Shelby tube. The drill rod assembly wdU then be rotated 1/4 to 1/2 tum to separate the sample from the imderlying soUs. 5. The rod assembly with the Shelby tube sampler wdll then be withdrawn! from the boring. 6. The Shelby tube wdll be discormected from the driUing rod assembly and approximately 1 to 2 inches of soU wdll be removed from the bottom of the tube after it is recovered. 7. Both ends of the sample wdU then be sealed wdth several inches of paraffin, liquefied by heating. Care wdll be taken to completely seal the ends of the soU sample to prevent moisture loss 8. Once the paraffin has dried, any void space in the top of the tube will be fUled tightiy wdth a packing material, such as crumpled paper. Each end of the tube wdU be secured wdth a plastic end cap taped in place. 9. The outside of the Shelby tube wdU be labeled to indicate the sample identification, date of sampling, and top of the sample. Care wdll be taken to keep the sample in an upright position during handhng. Instructions wdll be provided to the carrier to ship the samples in an upright 302336 F:\3524i\WP\SAPP.DOC Harding Lawson Associates 3 DRAFT position. 2.3 Hydropunch® Groundwater Sampling Groimdwater samples wdU be coUected from the pilot boring for deep monitoring wells MW-6D, MW- 2D and a third deep monitoring well (location to be determined) using a Hydropunch® samphng device. The Hydropunch® is a 5-foot long samphng device that consists of a drive point; 1-inch diameter, 4-foot long disposable screen; and a retiactable stainless steel sleeve. The screen is made of poly vinyl chloride (PVC) or polypropylene. The Hydropunch® wdll 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 wiU be removed. 2. The Hydropunch® sampler, equipped wdth an unused, disposable screen, wdll be attached to the driU rods and set at the bottom of the boring. 3. The Hydropunch® sampler wdU be driven into the formation using a 140- or 300-pound hammer. The Hydropunch® sampler wdll be driven 4-feet into the formation or until refusal is encountered. A total of 100 blows over a six-inch interval wdU be considered refusal. The nmnber of blows and distance driven wdU be recorded. 4. If the Hydropunch® sampler is driven less than 1-foot before refusal is encountered, no sample wiU be collected, the boring wdU be advanced 5 feet, and a second attempt wdll be made to drive the Hydropunch® sampler into the formation. 5. If the Hydropunch® sampler is driven 1-foot or more, the sleeve wdll be retiacted approximately one-half the distance that the samphng device was driven (i.e., retiact the sleeve 2 feet if the sampler is driven 4 feet), exposing the disposable screen to the formation. Sufficient time wdll be given to allow groundwater to flow into the Hydropunch®. An electionic depth-to-water probe wdU be lowered inside the driU rods and Hydropimch® to monitor groundwater recharge. 6. Groundwater will be aUowed to equihbrate in the Hydropunch® for a minimum of 30 minutes or until the water level inside the driU rods has reached 90 percent of the distance from the water table to the bottom of the sampler. 7. A field-decontaminated 1/2-inch diameter Teflon™ bailer wdU be lowered on Teflon™-coated stainless steel cable through the Hydropunch® rods to collect a groundwater sample from the screened interval. Prior to use at each sampling interval, the Teflon™ bailer and cable wdU be decontaminated followdng the procedures described in Section A2.4.2.2. The bailer holds approximately 20 ml. Therefor the bailer wdll be lowered several times at each interval to completely fiU the 40 ml vial wdth no headspace. 8. The color, qualitative and quantitative turbidity and other pertinent observations of the groundwater sample wiU be noted and recorded in the field book. 9. Approximately 20 miUihters (mL) of groundwater sample wdll be poured directiy 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 2.7. to Ui F:\3524i\WP\SAPP.DOC Harding Lawson Associates DRAFT 10. Co-located groundwater samples will be obtained for laboratory analysis at a rate of one sample for every ten screening samples. HLA wdll submit a minimum of one groundwater sample for laboratory analysis collected from zones displaying no detected volatUe organic compounds (VOCs) by field screening. The co-located samples wdU be coUected 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 Contiact Laboratory Program (CLP) methodologies as specified in the RIWP. The co-located samples will be coUected, preserved and handled as described in steps 23 tixrough 27 of Section A2.8 of the RIWP. 2.4 Mud Rotary Drilling Methods Mud-rotary drilhng methods wdU be utilized to advance the deep boring for the double-cased weU in the AST area. Mud-rotary driUing techniques are described below. Double cased well construction is described in Section 2.5.1.1 1. Prior to set up, the drill rig and equipment wdll 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 wdll be placed at the selected driUing location. The mud tub wdll contain baffles to enhance setdement of sohds enfrained in the drilhng fluid. 3. A tri-cone roller or wdng bit wdll be attached to the driU rods. 4. The mud tub wdU be partiaUy fUled with potable water. The potable water wdll be obtained from the drUler's office, consistent wdth previous work on this project. The driller wiU then cfrculate the water through the driUing 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 wiU be estabhshed in the field at the discretion of the driller. 5. Once the driller is satisfied that the driUing fluid is of adequate consistency, the drUler will advance the borehole to the desfred depth. During drilling, the drilling fluid wdll be pumped down through the drilling rods. The fluid wdU circulate to the ground surface by rising in the annular space of the boring. Cuttings from the boring wdU be enfrained with the rising fluid and wiU be separated to the extent possible in the mud tub at the surface. The viscosity of the fluid may be altered during drUling activities at the driller's discretion by adding water or mud. 6. During drilling, solids wdU be removed from the mud tub as needed and containerized onsite in 55-gaUon drums. Drummed investigation-derived waste wiU be staged onsite untU proper disposal arrangements are completed. 7. SoU samples wdll be coUected and logged as described in Section A2.4.3 of the SAP. 8. The volume of driUing fluid lost to the formation wdll be monitored during driUing and recorded on the field boring log. 2.5 Monitoring Well installation DrUUng methods for the instaUation of monitoring weUs wiU be selected based on field conditions and the anticipated depth of the borehole. It is anticipated that the borings for the shaUow soU zone wdll be driUed using hoUow-stem augers and that mud-rotary drilling methods wdll be necessary for the 302338 F:\3524i\WP\SAPP.DOC Harding Lawson Associates 5 DRAFT installation of deeper wells. Mud-rotary drUling methods may also be necessary for installation of shallow monitoring wells if problems wdth 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 weUs are described in Section A2.5 of the RIWP. Well construction detaUs wdll be recorded by an HLA geologist. Equipment decontamination wdU be conducted as described in Section A2.4.2 of the RIWP. 2.5.1 Double-Cased Well Construction The followdng procedures wdll be implemented during installation of the double-cased monitoring well at the site: 1. Prior to set up, the dxUl rig and equipment wdU be decontaminated by steam cleaning and/or a potable water wash as described in Section A2.4.2 of the SAP. 2. The driller wdU advance a 12-inch diameter boring to approximately 5 feet above the predicted water table depth using mud-rotaiy drUhng techniques as described in Section 2.4. The approximate depth to the water table wdU be estimated before drilling activities begin based on groundwater elevations measured at nearby monitoring weUs. 3. Beginning at this depth, the driUer wdll coUect soU samples using a split-spoon samphng device as described in Section A2.4.3. Spht-spoon samples wdU be coUected continuously untU the water table is encountered. An HLA geologist wdU examine the soil samples to determine the level of the water table. 4. The driUer will then advance the boring to 5 feet below the screened interval of the adjacent monitoring weU or at a confining unit, whichever is encountered first. 5. An 8-inch diameter steel casing with welded or threaded joints wdU be lowered to the bottom of the boring and centered. The casing wdll be long enough to extend to the groimd surface and wdll be seated using a hammer assembly. 6. A Portiand cemenVbentonite grout wdll be emplaced from the bottom up in the annulus around the casing using a tiemmy pipe. The grout wdU 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, the driUing fluid inside the casing wdU be circulated thoroughly wdth potable water until visible drilhng fluids have been removed and clear water remains inside the casing. 8. Drilling equipment wdll be decontaminated and the driUing fluid wdll be replaced. If possible, water wiU be used instead of mud to diiU the remainder of the boring, li mud is necessary, efforts wdll be made to minimize the amount of mud added to the driUing fluid. 9. An 8-inch diameter boring wriU be advanced through the casing to the final well depth. Sampling wdU be performed as appropriate foUowdng procedures described in other sections of the RIWT. w o to Ui w VD F:\3524i\WP\SAPP.DOC Harding Lawson Associates DRAFT 10. The remainder of the weU constiuction methods wdU be the same as those used to construct single-cased monitoring weUs as described in Section A2.5.1 of the RIWP. Figure 3-2 depicts typical double-cased monitoring well construction. Equipment decontamination wdU be conducted as described in Section A2.4.2 of the RIWP. 2.5.2 Temporary Monitoring Well Construction Temporary groundwater monitoring wells wdU be installed following the methods described in Section A2.5.1 for single-cased monitoring wells. In general, the followdng procedures will be used unless field conditions require modifications: 1. Prior to set up, the driU rig and equipment wdll be decontaminated by steam cleaning and/or a potable water wash as described in Section A2.4.2 of the SAP. 2. The drUler wiU advance a 6.5-inch diameter boring to approximately 5 feet below the predicted water table depth using hoUow-stem auger driUing techniques as described in Section A2.4.1. The approximate depth to the water table wdll be estimated before drilling activities begin based on groundwater elevations measured at nearby monitoring wells. 3. Beginning at this depth, the driller wdll collect soU samples using a spht-spoon sampling device as described in Section A2.4.3. Spht-spoon samples will be collected continuously until the water table is encountered. An HLA geologist wdll examine the soU samples to determine the level of the water table. 4. The driller wdU then advance the boring to between 5 and 6 feet below the water table. 5. The temporary monitoring well wiU be constructed of 2-inch diameter, schedule 40, flush-joint, threaded PVC wdth a 10-foot section of 0.020-inch factory-slotted screen. The PVC well wdll 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 wdU be constructed inside the augers before they are removed. If the boring is driUed using rotary drilling techniques, the drilling tools wdll be removed before the weU is constructed. 6. The boring will be aUowed to collapse naturaUy around the weU screen. If necessary, a small amount of filter sand wdll be poured into the boring to bring the bottom of the boring to the appropriate depth. If addition of sand is necessary, it will be poujed slowly to avoid bridging. 7. Plastic sheeting wdll be taped securely around the riser pipe approximately one foot above grade and spread out to fonn a skirt that extends radially at least 18 inches from the center of the weU. The edges of the skirt wUl be covered and weighted prevent runoff from entering the weU annulus. 8. The temporary well wdU be capped with a locking, expandable plug. 9. If the well boring is advanced using mud rotary driUing techniques, the well wdU be initially developed by pumping and surging with potable water to remove the visible drilhng fluid. After a minimum of 48-hours followdng the initial development, the temporary weU wdll be developed again using the same techniques. If the weU is instaUed using hoUow-stem augers or water rotary methods, only one phase of well development wdU be performed. 302340 F:\35Z4i\WP\SAPP.D0C Harding Lawson Associates 7 DRAFT Equipment decontamination wdll 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 wiU be reamed and the well constructed as described in Section A2,5 of the RIWP. If the weU is not converted to a permanent monitoring weU, the temporary well wdU be abandoned by removing the 2-inch casing and screen and backfUling the boring with powdered bentonite. 2.6 Low Flow Purging and Groundwater Sampling Groundwater monitoring wells wiU 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 preparation, and sampling apparatus decontamination procedures wdll be consistent wdth the RIWP. The low-flow groundwater samphng procedures are described below: BEFORE ENTERING THE FIELD • Project objectives and quahty assurance procedures, sampling locations, samphng procedures, preservation, packaging and shipping requirements, and analjrtical parameters will be reviewed with field persormel. • Previous water level measurements for each weU, if available, will be reviewed before leaving for the site, and a summary of previous water level data wdll be taken to the field, • Health and safety procedures wdll be reviewed wdth aU personnel. • A hst of weUs to be sampled and analyses to be performed wdll be prepared and tiansmitted to the laboratory. • All field equipment will be tested to ensuie that it is operating properly. Because of the remote location of the site, duphcate instruments will be mobUized to limit down time due to possible equipment malfunction. • The laboratory wdU provide clean glassware required to coUect the samples. The glassware wdU be cleaned in accordance wdth OSWER Directive 9240.0-05A. The glassware wdll include required preservatives and a list of which preservatives correspond to each analyte wdll be included wdth the glassware. The laboratory wdll provide sufficient glassware and/or samples for trip blanks, field blanks, and duphcate samples to be collected at the frequency described in the Quahty Assurance Project Plan (QAPP) presented in Appendix C of the RIWP. IN THE FIELD • Sampling crews wdll receive labeled sample kits from the field manager and wdll confirm that the kits contain appropriate sample botties, preservatives, filter pumps, ice, sample labels, chain-of- custody records, and well construction information. •^ Ui o • Before purging or sampling each well, equipment wdll be decontaminated. Decontamination of to pumps wdll include rinsing the pmnp and tubing wdth soapy water and deionized water before J^ use. M F:\3524i\vnASAPP.DOC Harding Lawson Associates 8 DRAFT • The well number, date, pertinent observations (e.g., weather, weU condition), casing diameter, screened interval, and field instrument identifications will be recorded on groundwater sampling forms . • Monitoring instruments wdll be calibrated against known standards before making well measurements (generally calibrated once per day). Cahbration wiU be recorded on field cahbration data sheets . • The weU wdll be uncapped from the upwind direction and a photo-ionization detector (PID) or flame-ionization detector (FID) wdU be used to record relative organic vapor concentiations upwdnd from the weU, at the top of the casing and wdthin the well casing. Procedures for use of the FID or PID wdU be consistent wdth the manufacturer's manual, which may vary slightiy from model to model. The manual wiU be kept onsite at all times during equipment use. • Depth to water wdll be measured using an electionic interface probe. The probe wdU be lowered into the well until a contact wdth the water surface is indicated by an electionic signal. • The tape wdll be marked or held at the measuring point. • The electric tape wdll 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. • The depth to water will be measured to an accuracy of 0.01 foot. • The probe wdll then be lowered below the groundwater and raised until the signal indicates that the probe is above the water table. The depth to water wdll be measured again as described in steps 7 through 9 above. • The groundwater elevation relative to mean sea level (MSL) wiU be determined by subfracting 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 inner casing and wdll be repeated until two consecutive measurements are obtained that agree wdthin ±0.02 foot Water level measurements wiU be recorded on water level measurement forms (Appendix AA). WeU identification, date, time, depth in feet to groundwater and remarks relevant to groundwater level measurements will be noted. Previous water level measurements for the weU wdU be checked. If the difference between the current water level and the previous water level is greater than one foot, the water level wdU be remeasured. • The sample (pump intake) depth wiU be determined before sampling equipment is intioduced into the well. Ln the wells in which the water level is above the top of the screen, the pump intake wdU be set at the middle of the screened interval. If the well is screened across the water table, the pump intake wiU be set at the mid-point between the groundwater level and the bottom of the well. Every effort wdU be made to avoid placing the pump intake or water level indicator within two feet of the bottom of the weU. • A field-decontaminated 2-inch diameter stainless steel submersible electrical samphng pump (Grunfos'"^ Redi-Flo ll"^ or equivalent) and dedicated 1/2-inch diameter Teflon'"^ -hned tubing (tubing inner diameter wdU be between 1/4 and 3/8 of an inch) wdU be used to purge and sample the weU. 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 settied on the bottom, the pump and tubing wdll be carefully and slowly lowered to the pre-determined 302342 F:\3524i\WP\SAPP.DOC Harding Lawson Associates 9 DRAFT instaUation depth. • Depth to water wdll be measured after the pump has been installed to evaluate the effect of water displacement Prior to purging, a final depth-to-water measurement wdU be recorded. At the start of purging, the flow rate wdll be monitored until a rate between 0.1 and 0.5 liters per minute (Lpm) is obtained. The flow rate wdll 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 wdll be made to keep drawdown to less than 0.1 meters (0.328 feet) during purging. If this minimal drawdowm caimot be sustained, the water level wdU be monitored until a constant drawdowm is achieved. • If drawdown does not stabUize at the minimum purge rate of 0.1 Lpm, the pump wdll be shut down periodically during purging to aUow the weU to recharge so that the water level does not faU below the pump during purging. • After the drawdown has stabilized, HLA will measure specific conductivity, temperature, pH, reduction/oxidation (Redox) potential, dissolved oxygen (DO), and turbidity using an in-hne flow- through cell approximately every three to five minutes. Efforts wdll be made to sustain turbidity measurements less than 25 nephelometric turbidity units (NTUs) for the three monitoring cycles. Field measurements will be performed at a minimum of once every 3 minutes as described in Section A4.0 of the SAP. • Purging wiU continue until the foUowing five parameters measured in the field have stabilized for three successive readings. Readings wdll be considered stabihzed based on the foUowing criteria set forth by EPA {Groundwater Issue, April 1996): - Conductivity ± 3 percent - pH ±0.1 Standard Units - Redox potential ± 10 mUlivolts - DO ±10 percent - Turbidity ± 10 percent Temperature will be monitored but wdll not be used to estabhsh stabUization. • Data on method and amount of water purged wdll be recorded on a groimdwater samphng form (Appendix AA). • Water purged from the monitoring wells will be collected and stored at the site in properly labeled 55-gaUon drums. The information specified on the drum label(s) wdU include, at a minimum, the date and well number(s) corresponding to the wells from which the water was removed. The water wdU be stored untU final disposal arrangements are completed. • Sample collection wdll begin immediately after the five parameters noted above have stabUized. • During sample coUection, the flow rate wdU remain the same as the estabhshed purge rate. w • Except as noted in Step 24 and in Section A2.9, groundwater samples vdU be tiansferred directiy to from the pump discharge to. the sample containers. VOC vials wdll be fUled in a manner that w minimizes head space or air bubbles. Samples for VOC analyses wiU be collected first. VOC ^^ sample vials wdll be fUled to capacit}' and tightiy capped to avoid retention of air bubbles. F:\3524i\vmSAPP.DOC Harding Lawson Associates 10 DRAFT Remaining sample containers wdll be filled to approximately 90 percent of capacity. VOC sample containers wdU be preserved and filled according to EPA Region II CERCLA Quality Assurance Manual protocol (p. 31) as follows: - CoUect three 40-milhliter vials of sample for VOC analysis. - Adjust the pH of one of the vials to less than 2 Standard Units by carefuUy adding 1:1 Hydrochloric acid (HCl) drop by drop to one of the fiUed 40-millUiter VOA vials. The number of drops of 1:1 HCl requhed wdll 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 directiy.) - Seal the vials. - The pH test is to be performed at each sampling location. - A fresh sample wdll be collected if an air bubble is detected in a VOC sample vial after samphng is complete. Non-VOC samples wdll be placed into pre-preserved laboratory-prepared sample botties. A smaU portion of the sample wdU be poured over pH paper from the filled sample bottie into a second clean container. The pH of the sample material in the second container wdU be tested in the field to confirm that it falls wdthin the reqmrements of the QAPP. Additional preservative and sample material wdll be used to adjust the pH of the sample, if necessary. • Immediately after filling, samples wdll be placed in storage coolers on ice. Samples wdll be checked periodically wdth a thermometer to ensure preservation reqmrements are met The temperature of the samples wdll also be recorded by the laboratory upon receipt. • Sample depth wdll be recorded, the groundwater sampling field data sheet wdll be completed and signed, and the chain-of-custody form wdll be signed. • The weU cap wdll be closed and the well wdll be locked. Quahty assurance/quahty contiol (QA/QC) samples are discussed in the QAPP (Appendix C). 2.7 Onsite VOC Analysis by Gas Chromatograph Groundwater samples wdll be handled and analyzed onsite using a portable GC as described below. • Groundwater samples wdll be collected as described in steps 2 through 21 of Section 2.6. • 20 mLs of groundwater wdll be coUected in a 40-mL vial. • The sample wdU then be agitated (shaken) for 2 minutes. • A dedicated syringe wdU then be inserted into the vial and a measm-ed volume of gas from the sample vial headspace wdll be collected for analysis using the GC. The GC utilized wdll be a PED equipped wdth an 10.6 election volt lamp. The chromatographic column wdU be a 10-meter capUlary column of fused sihca coated wdth the adsorptive material. The inner diameter of the capillary column wdll be 0.021 inches (0.53 mm). Precolumn backflush wdU use a 9-meter analjdical column and a l-meter precolmnn. Computing integrators wdll be used to plot the 3 02344 F:\3524i\WP\SAPP.DOC Harding Lawson Associates 11 DRAFT chromatogram for the detector analysis and to compute and record the area of the chromatographic peaks. The peak areas wdU be used to calculate concenfrations for each of the compounds analyzed. The field QC procedures wdll be performed as set forth in the QAPP addendum (Appendix CD). As discussed during the May 12, 1997 meeting wdth EPA, the results of the proposed onsite analysis of TEX compounds in groundwater using a field gas chromatograph (GC) wdU be defined as "Screening Data wdth Definitive Confirmation". A detailed definition of "Screening Data wdth Definitive Confirmation" was supplied to the EPA in Section C2.0 of HLA's Draft Remedial Investigation Workplan (Workplan), dated August 5, 1994. Confirmatory samples will be coUected at the rate (10%) described in this Workplan. The confirmatory samples wdll be analyzed using CLP methodologies by a certified laboratory. Field screening wdll be performed on the headspace of a water sample utihzing a GC equipped wdth a photoionization detector (PID). The field screening method is based upon the principle that when a water sample containing VOCs is sealed in a vial, VOCs wdll equUibrate between the water and vial headspace. The apphcation of field screening methods for determination of VOCs in water has been rehably demonstiated as described by the foUowing : Mackay, D., Shiu, W.Y., and Wolkoff, A.W., 1975: Gas Chromatographic Determination of Low Concentiation of Hydrocarbons in Water by Vapor Phase Extiaction; in Water Quahty Parameters, ASTM STP 573, American Society for Testing and Materials, p. 251-258. ; And McAuhffe, J., 1976: GC Determination of Solutes by Multiple Phase Equihbrium; Chemical Technology, v.l p. 46-51. This method of field screening has also been compared to purge and tiap procedures wdth excellent correlation and exhibits a standard deviation of 5% for routine analysis of water as described by the foUowing : Dietz, E.J., jr. And Singley, K.F., 1979: Determination of Chlorinated Hydrocarbons in Water by Headspace Gas Chromatography; Analytical Chemistry, v.51 No. 11 p. 1809-1814. 2.8 Aquifer Slug Testing Aquifer slug tests wdll be performed at select wells during the implementation of the RIWPA. One rising head test wdll 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 wdll be performed. The tests wdll be conducted using a data logger and pressme fransducers wdth chemicaUy resistant cables. The data logger wdll be pre-programmed to collect incremental water level measurements using an approximately logarithmic time scale. Field decontamination procedures wdll be conducted as described in Section A2.4.2.2. The followdng procedures wiU be used during the slug tests: 1. Before begiiming each test, the following information will be recorded: • WeU intemal diameter Ui • 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 w cn Date, time, and name(s) of personnel conducting test F:\3524i\WP\SAPP.DOC Harding Lawson Associates 12 DRAFT • Well, depth, screen depth and length, well radius, and depth, length, and radius of the gravel pack • Volume of dimensions of slug • Type of test (faihng or rising head) • Test number as recorded by the data logger • Type of measuring device used 2. An initial depth-to-water measurement wdll be coUected and recorded. 3. A decontaminated pressure tiansducer wUl be lowered into the well to a depth below the anticipated greatest depth of the slug. The water level wdU then be allowed to equihbrate. 4. The data logger wdU be initiahzed and set to the referenced water level 5. To initiate the falling head test, a decontaminated PVC or stainless steel slug wdU be completely infroduced into the well as rapidly as possible while the data logger is started simultaneously. The slug wdU be of sufficient volume to displace a quantity of water that wdU require the well at least five minutes to equihbrate. 6. The faihng head test wdll continue untU the water level has returned to 90 percent of static. 302346 F:\3524i\vmSAPP.DOC Harding Lawson Associates 13 DRAFT 7. Once the water level has retumed to static, the rising head test can begin. The rising head test wdll be conducted by completely removing the slug from the well as rapidly as possible while simiUtaneously starting the data logger simiUtaneously started. The rising head test wdll continue untU the water level returns to at least 90 percent of static. 8. The data will be downloaded directiy from the datalogger to a portable computer in the field. The data wdU be used for analysis (using AQTESOLV®) of hydrauhc conductivities using the Bower and Rice method. 9. If the data cannot be dowrnloaded directiy to a computer, the data will be printed in the field. A field geologist or engineer wdll keep detailed notes for each test. Ui o to Ui F:\3524i\WP\SAPP.DOC Harding Lawson Associates 14 APPENDIX C QUALITY ASSURANCE PROJECT PLAN ADDENDUM 302348 DRAFT APPENDIX CD CONTENTS GDI INTRODUCTION...., 1 CD2 ONSITE VOC ANALYSIS USING THE GC 2 CDS LABORATORY ANALYTICAL PARAMETERS AND METHODS 4 CD3.1 Onsite GC Analysis 4 CD3.2 Certified Laboratory Procedures 4 302349 F:\3524i\WP\QAPP.DOC Harding Lawson Associates i DRAFT CDI 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 wdU be included in the RIWP as Appendix CD. The RIWP Addendum (RIWPA) iiicludes the foUowing anal3rtical activities which were not specified in the original EPA-approved RIWP, and therefore not included in the original QAPP: • Onsite analysis in groundwater using a gas chromatograph (GC) • Shelby tube soU sampling for analysis of grain size, percent moisture, total orgaruc carbon (TOC), and porosity • Nutrient profUe in soU including analysis of alkalinity, ammonia, iron, sulfate, sulfide, nifrate, nitrite, pH, and ortho phosphoms. Other procedures and quahty assurance and quality contiol (QA/QC) protocol for activities planned during the implementation of the RIWP Addendum are discussed in the RIWP- Quality Assurance and Procedmes Plan (QAPP, Appendix C). 302350 F:\3524i\WP\Q.APP.DOC Harding Lawson Associates 1 DRAFT CD2 ONSITE VOC ANALYSIS USING THE GC Sample docmnentation wdU be consistent wdth that described the QAPP (Section 3.0), with the exception of a chain-of-custody form. The samples coUected for onsite analysis wiU be logged in the field book, and analyzed immediately after coUection. The followdng information wiU 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 cahbration and maintenance records of the onsite GC wdU 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 wiU maintain spare parts for eqmpment and wdll be capable of making minor repafrs as needed. Cahbration records will be maintained as foUows: 1. The GC operator wiU maintain a calibration record that wiU 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 applicable). Reports and compensation or correction figures will be maintained with the instrument. 3. Written step-wdse cahbration procedures wdU be available for each measurement instrument. The cahbration procedures for the field GC are described below (Source: Vironex Field Analytical Services): 1. GC operator wdU perform a two-point calibration using a 5 microgram per hter (fig/L) SOjig/L and a 500 ug/L standard of target compounds (toluene, ethylbenzene, and xylenes [TEX]), The 5 ug/L standard is prepared by fiUing a 40 milhliter (mL) vial wdth 20 mLs of deionized water and adding .5 microliters (pL) of a 200 ng/mL standard solution of VOCs in methanol. The 50 fig/L standard is prepared by fiUing a 40 mL vial wdth 20 mLs of deionized water and adding 5 )j.L of a 200 (ig/mL standard solution of VOCs in methanol. The 500 |ig/L standard is prepared by filhng a 40 mL vial wdth 20 mLs of deionized water and adding 50 ^L of a 200 ng/mL standard solution of VOCs in methanol. The detection limits (e.g. Sjxg/L) wdll be verified prior to sample analysis and at the start of each day 2. Agitate (shake) standards for 2 minutes prior to analysis. 3. Calculate the response factor (RF) for each target compound for each cahbration concentiation 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 cahbration. 5. Determine percent relative standard deviation (%RSD) for each target compound (the RSD may not exceed 20 percent). 302351 F:\3524i\WFAQAPP.DOC Harding Lawson Associates DRAFT The GC analysis QA/QC techniques and frequencies are summarized below: • Analyze a 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 containing one or more target compounds. • Analyze one standard after every 10 samples. • Analyze one duplicate sample for every 20 samples. • Calibrate the instrument 1) at the start of each day, or 2) when the GC operating conditions have changed, or 3) when the GC column type is changed, or 4) when the RF of the daily mid- point cahbration check is not wdthin 85 percent to 115 percent of the average RF from the initial cahbration. • Analyze a matrix spike sample and matrix spike duplicate samples at a rate of one per 20 samples. Groundwater samples wdll be analyzed onsite wdth a modified EPA Method 602 for toluene, xylenes, and ethylbenzene. A portable GC/PID (Photovac llS-l-) equipped with a 11.7 election volt lamp wdll be utUized for analysis. The groundwater samples wiU be handled and analyzed as described below. 1. Groundwater samples will be coUected as described in steps 2 through 21 of Section AD2.6. 2. 40 mis of groundwater will be collected in a 40-ml vial and the cap with a Teflon septum wiU be sealed wdth no headspace. The sample will then be submitted to the onsite GC operator. 3. The operator wdll then tiansfer a 20-ml ahquot of sample to a second, clean 40 ml VOA vial and the cap will be sealed, 4. The 20-ml sample wdll then be agitated for 2 minutes in the vial. This process efficientiy fransfers the aromatics from the aqueous phase to the vapor phase (McAuliffe, 1976). '. 5. A dedicated gas-tight S3Tinge will then be inserted into the vial and a measured volume of gas wdll be collected from the sample vial headspace. 6. The measured volume of gas wdll be injected into the gas chromatograph column, which wdU have been preheated to a temperatm-e of 40° Celsius. The chromatographic column wdll be a 10-meter capiUary column of fused sUica coated with the adsorptive material. The inner diameter of the capillary column wdU be 0.021 inches (0.53 mm). 7. The gaseous sample wiU be tiansported through the capiUary column by laboratory grade 99.99 % hydrocarbon free purified an. The GC is temperature programmed to separate the purgeables to be detected by the PID. The sample wdll then pass the PID where it wiU be ionized by the 11.7 eV lamp. Computing integrators wdU be used to plot the chromatogram for the detector analysis and to compute and record the area of the chromatographic peaks. The peak areas wdll be used to calculate concentiations for each of the compounds analyzed, • Precolumn backflush will use a 9-meter analytical column and a 1-meter precolumn. The field QC procedures will be performed as set forth in the QAPP addendum (Appendix CD). Ui o to Ui Ul to F:\3524i\WP\QAPP.DOC Harding Lawson Associates DRAFT CD3 LABORATORY ANALYTICAL PARAMETERS AND METHODS Several groundwater samples wiU be submitted for onsite GC VOC analysis. A certified laboratory will perform several analyses on soil samples. Analytical parameters and methods for the onsite GC analysis are described in Section CD3.1. Analytical parameters and methods for the certified laboratory analyses are identified in Section CDS.2. CD3.1 Onsite GC Analysis The onsite analysis using the GC wdll be conducted in accordance with EPA Methods 601 and 602 Modified. The method detection limits (MDLs) for the target compounds are as follows: Toluene Ethylbenzene Xylenes Methylene chloride Chloroform 5 ug/L 5 ^ig/L 5 Hg/L 5 ug/L 5 fig/L The GC that will be used to perform the onsite analyses can estimate concenfrations lower than those hsted above. If detected concenfrations are below the given MDL, the result wdll be quahfied to indicate that the concenfration is estimated. CD3.2 Certified Laboratory Procedures 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 Nifrate Nifrite Sulfate Sulfide fron (total) Alkalinity Ammonia Ortho Phosphoms Total Organic Carbon pH Grain Size Analysis Porosity HCU bacteria count Total plate bacteria count Percent moisture METHOD EPA Metiiod 353.2 EPA Method 353.2 SW-846 9036 SW-846 9030 EPA Metiiod 6010 EPA Metiiod 310.1 EPA Metiiod 350.2 EPA Metiiod 365.1 SW-846 9060 SW-846 9045 C Modified (M) ASTM D-422 By ASTM D-2216 and D-854 Standard Methods 9215CM Standard Methods 9215C M EPA 160.3 Modified 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 Apphcable Not Applicable Not Apphcable Not Applicable Not Applicable Not Applicable NOTES: mg/kg = milligraini per kilogram. The listed reporting limits are subject to a slight change based on moisture content. 302353 F:\35241\WF\QAPP.DOC Harding Lawson Associates DRAFT DISTRIBUTION Draft Remedial Investigation Work Plan Addendum-Phase III Virgin Island Chemical Site St. Croix, U.S. Virgin Islands July 25, 1997 Copy No. ' / Copies 1-7: Copy: 8 (unbound): Copy 9: Copies 10 -11: Copy 12 - 13: Copies 1 4 - 1 5 : Ms. Caroline Kwan United States Environmental Protection Agency Region n Emergency and Remedial Response Division 20th Floor 290 Broadway New York, New York 10007-1866 Ms. Carol Bums, Esq. Office of Regional Counsel United States Envfronmental Protection Agency 290 Broadway New York, New York 10007-1866 Mr. Cecil WUliams Mr. Syed Syedah Department of Planning and Natural Resources Division of Envfronmental Protection Bldg. I l l - Apt. 14A Water Gut Homes - 1118 Christiansted, St Croix U.S. Vfrgin Island 00820 5065 Ms. Pamela J. Phihps CDM Federal Programs Corporation Suite 710 111 Fulton Stieet New York, New York 10038 Sills, Cummis, Zuckerman, Radin, Tischman, Epstein & Gross One Riverfront Plaza Newark, New Jersey 07102-5400 302354 DRAFT DISTRIBUTION (continued) Copies 16-19: Harding Lawson Associates Princeton Junction, New Jersey Quahty Assurance/Quality Contiol Reviewer Jason M. Schindler, P.G. Associate Hydrogeologist This document was preparedfor the sole use ofthe ICC and the regulatory agencies involved with the project, the only intended beneficiaries of our work. No other parties should rely on the information contained herein without the prior written consent of HLA. JSV/jmc/ F:\35241\WP\WORKPLAN.DOC