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Home My WebLink AboutDSHW-2024-005556 WASATCH ENVIRONMENTAL, INC. ENVIRONMENTAL SCIENCE AND ENGINEERING 2410 WEST CALIFORNIA AVENUE SALT LAKE CITY, UTAH 84104 PHONE (801) 972-8400 FAX (801) 972-8459 e-mail: wei@wasatch-environmental.com www.wasatch-environmental.com ADDITONAL INVESTIGATION WORK PLAN ARMS TECHNOLOGY EAST SHOP 1142 SOUTH 2475 WEST SALT LAKE CITY, UTAH PROJECT NO. 2619-004C PREPARED FOR: MR. DOUG HANSEN UTAH DEPARTMENT OF ENVIRONMENTAL QUALITY DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL 195 NORTH 1950 WEST, 2ND FLOOR P.O. BOX 144880 SALT LAKE CITY, UTAH 84114-4880 PREPARED BY: WASATCH ENVIRONMENTAL, INC. 2410 WEST CALIFORNIA AVE SALT LAKE CITY, UTAH 84104 801-972-8400 FAX: 801-972-8459 MARCH 26, 2024 Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 1 TABLE OF CONTENTS Section Page No. 1. INTRODUCTION AND OBJECTIVES ............................................................................................. 2 2. SITE BACKGROUND ...................................................................................................................... 2 3. SITE INVESTIGATION ACTIVITIES ................................................................................................ 5 3.1 Groundwater Monitoring Well Installation, Development, Surveying, and Sampling ......... 5 3.2 On-Site Additional Boring Sampling.................................................................................... 6 3.3 Off-Site Groundwater Sampling .......................................................................................... 6 3.4 Indoor Air Sampling............................................................................................................. 6 4. SAMPLING METHODOLOGY ......................................................................................................... 6 4.1 Groundwater Monitoring Well Installation, Development, Surveying, and Sampling ......... 6 4.2 On-Site Additional Boring Sampling.................................................................................... 7 4.3 Off-Site Groundwater Sampling .......................................................................................... 8 4.4 Indoor Air Sampling............................................................................................................. 8 5. REPORTING .................................................................................................................................... 9 FIGURES Figure 1 – Site Location Map Figure 2 – Historical and Proposed Sample Location Map Figure 3 – TCE in Groundwater Concentration Map Figure 4 – TCE in Soil Gas Concentration Map Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 2 ADDITIONAL INVESTIGATION WORK PLAN ARMS TECHNOLOGY EAST SHOP 1142 SOUTH 2475 WEST SALT LAKE CITY, UTAH 1. INTRODUCTION AND OBJECTIVES In accordance with the Utah Division of Waste Management and Radiation Control (DWMRC) request, we have prepared this work plan for conducting investigative activities at the Arms Technology east shop (Site), owned by ATI Corporation, located at 1142 South 2475 West in Salt Lake City, Utah. See Figure 1 for a Site Location Map. This work plan has been prepared to evaluate groundwater flow direction, evaluate volatile organic compound (VOC) and semi-volatile organic compound (SVOC) impacts to groundwater at the Site, and evaluate indoor air concentrations at the Site. The objectives of this work plan are to:  Install, develop, survey, and sample groundwater monitoring wells at the Site to evaluate the groundwater flow direction, evaluate on-Site VOC and SVOC impacts to groundwater, and evaluate the potential for VOC impacts to be migrating onto the Site from an off-Site source;  Complete two off-Site borings to evaluate potential VOC and SVOC impacts that may be migrating onto the Site; and  Complete one on-Site boring to further evaluate arsenic impacts in the area of the known elevated arsenic in groundwater impacts.  Collect indoor air samples to evaluate the potential for VOC impacts to on-Site commercial workers. This work plan describes the sampling and analytical procedures that will be used for sampling to be performed during investigation activities at the Site. 2. SITE BACKGROUND Wasatch completed a Phase I Environmental Site Assessment (ESA) dated September 21, 2023, for the Site on behalf of Buchalter (the legal representative of the potential purchaser of the Site). This report identified the following recognized environmental conditions (RECs) and recommended additional investigation be completed:  There is a potential for releases to the Site from the long-term use of the Site for manufacturing and as a machine shop.  There is a potential for releases from the long-term use of adjoining properties for chrome plating and heavy industrial uses to have impacted the Site.  There are known chlorinated solvent impacts to groundwater on the south adjoining property that have likely migrated onto the Site. On October 25, 2023, Wasatch completed seven soil borings (GP-1 through GP-7) at the Site to evaluate the identified RECs. Borings GP-1, GP-2, and GP-3 were completed in the areas hydraulically downgradient from adjoining south/southeast properties where potential impacts may be migrating towards the Site. Boring GP-4 was completed adjacent to the sump to evaluate potential releases in this area. Borings GP-5, GP-6, and GP-7 were completed hydraulically downgradient of the building to Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 3 evaluate potential releases originating from the building. Additionally, boring GP-5 was completed adjacent north of the sump located in the shoot tunnel area to evaluate for releases from this feature. Additionally, Wasatch collected six sub-slab soil gas samples (SG-1 through SG-6) from beneath the on- Site building. Based on the data collected Wasatch concluded the following:  The suspected source area soil samples (GP-4 and GP-5 completed adjacent to the on-Site sumps) did not exhibit analyte concentrations that exceeded their applicable United States Environmental Protection Agency (U.S. EPA) Regional Screening Levels (RSLs) for Residential or Industrial Soil, except for arsenic. Based on Wasatch’s experience, the detected arsenic concentrations are within the typical background range of 20 to 30 mg/kg for this area. Therefore, it is Wasatch’s opinion that the detected concentration of arsenic in soil is within the typical background concentration range for the area.  All soil gas samples exhibited trichloroethene (TCE) and tetrachloroethene (PCE) concentrations that exceed the applicable U.S. EPA Vapor Intrusion Screening Level (VISL) Residential and Commercial Target Sub-Slab and Near-Source Gas Concentrations (TSSGCs). The TCE and PCE concentrations in soil gas indicated a release of TCE and PCE has likely occurred near soil gas samples SG-4 and SG-5. The detected TCE and PCE in soil gas concentrations indicated there is a potential that the rate of vapor intrusion into the building may result in TCE and PCE indoor air concentrations that exceed the U.S. EPA RSL for Industrial Air.  The arsenic concentrations detected in groundwater exceed the U.S. EPA Maximum Contaminant Level (MCL). Given the elevated arsenic in groundwater concentration exhibited by groundwater sample GP-1 (this boring was completed in an assumed hydraulically upgradient location at the Site to evaluate for impacts migrating onto the Site), it appeared that arsenic- impacted groundwater exceeding the U.S. EPA MCL was migrating onto the Site. However, based on the GP-7 arsenic concentration in groundwater there may be a source of arsenic impacts to groundwater near this boring. No other metals were detected at concentrations that exceed their applicable U.S. EPA MCLs.  Based on the GP-1 per- and polyfluoroalkyl substances (PFAS) groundwater data and assumed hydraulic gradient to the northwest or north, perfluorooctane sulfonic acid (PFOS)-impacted groundwater is migrating onto the Site at a concentration that exceeds the proposed U.S. EPA MCL.  TCE and PCE were detected in groundwater samples GP-2 and GP-3 at concentrations that exceed their applicable U.S. EPA MCL. These borings were completed on the assumed hydraulic upgradient boundary to evaluate if chlorinated solvent impacts were migrating onto the Site. Based on the GP-2 and GP-3 groundwater data, PCE, TCE, and cis-1,2-dichloroethene (CIS) impacts exceeding the U.S. EPA MCLs appear to be migrating onto the Site from the southern adjoining property.  PCE and TCE were detected in groundwater samples GP-5, GP-6, and GP-7 at concentrations that exceed their applicable U.S. EPA MCLs. These samples were collected hydraulically downgradient of the on-Site building. Based on these data, it appeared that a release of PCE and TCE was originating from the on-Site building.  Based on the data obtained from borings GP-4 and GP-5, it did not appear that a release from the on-Site sumps has occurred.  Based on the groundwater data, it appeared that a co-mingled (one potentially originating on-Site and one potentially originating off-Site) chlorinated solvent plume is present on the Site. Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 4  Given the totality of the data, it appears that a releases of chlorinated solvents and potentially arsenic have occurred at the Site. Wasatch recommended that these releases be reported to the Utah Department of Environmental Quality (DEQ). Wasatch also recommended that additional investigation be completed to define the nature and extent of these impacts. On January 8 and 9, 2024, Wasatch completed 11 additional borings (GP-8 through GP-18) at the Site to further evaluate the on-Site VOC and arsenic impacts to soil and groundwater. Based on the data Wasatch concluded the following:  Arsenic was detected in soil samples GP-12-15, GP-13-11, GP-15-7, and GP-17-11 at concentrations that exceed the U.S. EPA RSL for Residential and Industrial Soil. Based on Wasatch’s experience the average arsenic concentration in soil at the Site is within the typical background range of 20 to 30 mg/kg for this area. Arsenic was detected in groundwater samples GP-8-15, GP-9-15, GP-10-15, GP-12-15, GP-13-15, and GP-17-15 at concentrations that exceed the U.S. EPA MCL, and the GP-12-15, GP-13-15, and GP-17-15 concentrations exceed the Utah GQS of 50 µg/L. Given the total arsenic in groundwater data for the Site, it appears that the source of the groundwater impacts is located under the southwestern portion of the building. However, local arsenic impacts to groundwater above the U.S. EPA MCL also appear to be migrating onto the Site from an off-Site source.  Several VOC soil samples were collected above the water table in suspected source areas. Low concentrations of TCE and/or PCE were detected in the GP-14 (at 5 feet bgs), GP-15 (at 5 feet bgs), GP-16 (at 5 feet bgs), and GP-18 (at 5 feet bgs) borings above the water table. This indicates that minor surface releases have likely occurred in these areas. However, these detected TCE and PCE concentrations are below the U.S. EPA RSL for Residential and Industrial Soil but exceed the U.S. EPA Protection of Groundwater Soil Screening Level (PGWSSL).  No chlorinated solvents (including PCE, TCE, and CIS) were detected at concentrations exceeding their applicable U.S. EPA RSLs for Residential or Industrial Soil in the soil samples collected. However, soil samples GP-12-10, GP-13-1-0, GP-14-10, GP-14-15, GP-15-10, GP-15- 15, GP-16-10, GP-16-15, GP-17-10, GP-17-20, , GP-18-10, and GP-18-15 (all collected at or below the water table) exhibited PCE and TCE concentrations that exceed the U.S. EPA PGWSSL. This indicates there are soil impacts below the water table at sufficient concentrations to result in impacts to groundwater at concentrations that exceed the U.S. EPA MCL.  TCE and/or PCE were detected in all groundwater samples analyzed for VOCs at concentrations that exceed their applicable U.S. EPA MCLs. Additionally, CIS (a breakdown product of PCE and TCE) was detected at concentrations above the U.S. EPA MCL in groundwater samples GP-13- 15 and GP-17-15. Based on the groundwater data, PCE and TCE impacts to groundwater appear to be present across the Site.  Based on the totality of the groundwater data, PCE and TCE were detected along the northern, western, eastern, and southern boundaries of the Site. This indicates that PCE and TCE impacts may be migrating onto the Site, as the local groundwater flow direction is unknown but was assumed to be to the north or northwest. Additionally, groundwater samples GP-9-15 and GP-8- 15 exhibited the highest detections of PCE and TCE, respectively. These samples were collected along the western Site boundary. Based on the concentration gradients of PCE and TCE, it appears that the majority of the PCE and TCE impact may be originating from the adjoining west property and migrating to the east to northeast across the Site. Groundwater monitoring wells should be installed to verify the groundwater flow direction.  Three groundwater samples (GP-12-30, GP-13-30, and GP-17-30) were collected at a depth of 30 feet bgs beneath the building. PCE (ranging from 30.2 to 641 µg/L) and TCE (ranging from 5.87 to 116 µg/L) were detected at concentrations that exceed the U.S. EPA MCL. This indicates that PCE and TCE impacts have migrated to a depth of at least 30 feet bgs at the Site. Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 5  PFAS were not detected in any of the groundwater samples collected beneath the building. Therefore, it does not appear that the PFAS impacts detected on the southeast corner of the Site originate from the building.  Given the totality of the data, it appears that minor releases of PCE and TCE have occurred at the Site beneath the building. Additionally, it appears that the highest PCE and TCE impacts are potentially migrating onto the Site from an off-Site source. Also, arsenic concentrations in groundwater beneath the building appear to be elevated above the local concentrations observed. Wasatch recommends that these releases be reported to the Utah DEQ. Wasatch also recommends that additional investigation be completed including the installation of groundwater monitoring wells to define the nature and extent of these impacts under the guidance of the Utah DEQ. Wasatch submitted a DWMRC application to enter into regulatory oversight with the Utah DWRMC on February 20, 2024. The Site was accepted into the DWMRC Corrective Action program. DWMRC requested that additional environmental investigations be completed. Wasatch, DWMRC personnel, and the Client completed a virtual meeting on March 21, 2024, where several items of concern were discussed. In this meeting we discussed the sampling conducted at the sump located on the northwest corner of the Site and determined no further sampling was required to evaluate the sump. We also discussed the sump located along the northcentral wall of the on-Site building and determined no further sampling was required to evaluate the sump. Wasatch has provided DWMRC with the SDS sheets for the coolants used at the Site. Based on the SDS sheets, Wasatch did not identify a U.S. EPA RSL or MCL for any specific chemical that was listed on the SDS sheets provided. It is Wasatch’s opinion that the proposed groundwater monitoring wells below are sufficient to determine the Site groundwater flow direction and determine where groundwater is entering the Site. Currently, it is unknown what has caused the increased arsenic in groundwater concentrations in the southwestern portion of the on-Site building, but additional arsenic evaluation is discussed below. All other discussed items of the meeting are addressed in the sections below. 3. SITE INVESTIGATION ACTIVITIES 3.1 Groundwater Monitoring Well Installation, Development, Surveying, and Sampling Groundwater monitoring wells will be installed at the Site to evaluate VOC impacts to groundwater at the Site and to evaluate the potential for VOC impacts that may be migrating onto the Site from an off-Site source. The monitoring wells will be installed using the direct-push drilling methods. Soil core samples would be continuously collected from 5-foot long by 1.5-inch diameter discrete interval push samplers equipped with disposable polybutyrate liners. Soil samples would be collected continuously and field logged by an experienced geologist. The field logging would include a description of color, moisture content, consistency, odor, staining, and soil type based on the Unified Soil Classification System and screened in the field with a photoionization detector (PID). Monitoring well construction will consist of a 2.0-inch inner diameter (I.D.) polyvinyl chloride (PVC) well with a 10-foot screen to a depth of approximately 15 to 20 feet below ground surface. The monitoring wells will be developed to remove fines from the well screen prior to sampling using a pump or a disposable polyethylene bailer. In order to determine groundwater flow direction at the facility, top-of-casing elevations will be professionally surveyed by Robinson, Biehn & Biehn, Inc. Wasatch will obtain groundwater elevation measurements from each monitoring well using an electronic water level probe. The probe will be decontaminated between each monitoring well with a phosphate-free soap, rinsed with potable water, and then rinsed with de-ionized water. Based on the measurements obtained, Wasatch will construct a potentiometric surface elevation contour map to determine groundwater flow direction. Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 6 3.2 On-Site Additional Boring Sampling Wasatch will complete one additional soil borings to be completed just outside of the southwestern portion of the on-Site building to further evaluate arsenic impacts to soi land groundwater in this area. Two soil samples and one groundwater sample will be collected from this boring. This boring will be installed using the direct-push drilling methods. Soil core samples would be continuously collected from 5-foot long by 1.5-inch diameter discrete interval push samplers equipped with disposable polybutyrate liners. Soil samples would be collected continuously and field logged by an experienced geologist. The field logging would include a description of color, moisture content, consistency, odor, staining, and soil type based on the Unified Soil Classification System and screened in the field with a PID. 3.3 Off-Site Groundwater Sampling Wasatch will request that two soil borings be completed on the adjoining west, assumed hydraulically upgradient, property. Groundwater samples will be collected from these borings to evaluate VOC and SVOC impacts to groundwater that may be migrating onto the Site from an off-Site source. The borings will be installed using the direct-push drilling methods. Soil core samples would be continuously collected from 5-foot long by 1.5-inch diameter discrete interval push samplers equipped with disposable polybutyrate liners. Soil samples would be collected continuously and field logged by an experienced geologist. The field logging would include a description of color, moisture content, consistency, odor, staining, and soil type based on the Unified Soil Classification System and screened in the field with a PID. 3.4 Indoor Air Sampling To evaluate the potential risk to indoor air for commercial workers, Wasatch will collect indoor air samples within the on-Site building. To evaluate current background VOC concentrations present in ambient air in the vicinity of the Site so that comparisons can be made to indoor air concentrations present at the on-Site building, Wasatch will collect an outdoor air sample from the roof or an upwind area of the building. 4. SAMPLING METHODOLOGY 4.1 Groundwater Monitoring Well Installation, Development, Surveying, and Sampling Chlorinated solvents have been identified at concentrations exceeding its U.S. EPA MCL within the groundwater beneath the Site. Therefore, Wasatch proposes installing seven groundwater monitoring wells (MW-1 through MW-7) to achieve the stated objectives. The monitoring wells will be installed using the direct-push drill rig (GeoProbe 7822 or equivalent), using hollow-stem auger or direct-push drilling techniques. Wasatch proposes installing the following monitoring wells as depicted in Figure 2. Each well will be installed to a depth ranging between 15 and 20 feet below ground surface (bgs) depending on measured depth to groundwater. Each well will be completed with 10 feet of 2-inch 0.010- slot schedule 40 polyvinyl chloride (PVC) wells screen with 2-inch PVC well casing attached to the top of the well screen and extending to approximately 0.5 feet bgs. 10/20 silica sand will be placed as a filter pack material around the screen interval and extending at least 2 feet above the top of the screen interval. Bentonite chips will be placed from the top of the filter pack material up to ground surface and hydrated to form a well seal. Each well will be completed with a flush-mount surface completion consisting of an 8-inch steel well vault cemented in place. Once each well is installed, each well will be properly developed using over pumping well development techniques. A minimum of five well casing volumes of groundwater will be evacuated from each well; however, additional volume will be removed to sufficiently remove additional fines from the wells based Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 7 on Wasatch’s discretion. All evacuated groundwater will be placed within a steel 55-gallon drum(s) labeled as pending analysis to facilitate proper disposal. All soil cuttings will also be placed within a steel 55-gallon drum and labeled as pending analysis to facilitate proper disposal. To determine groundwater flow direction at the Site, top-of-casing elevations will be professionally surveyed by Robinson, Biehn & Biehn. Wasatch will obtain groundwater elevation measurements from each monitoring well using an electronic water level probe. The probe will be decontaminated between each monitoring well with a phosphate-free soap, rinsed with potable water, and then rinsed with de- ionized water. Based on the measurements obtained, Wasatch will construct a potentiometric surface elevation contour map to determine groundwater flow direction. The monitoring wells will be sampled using low-flow sampling techniques. Monitoring well sampling will involve inserting ¼-inch outside diameter, low-density polyethylene tubing into the newly installed monitoring well. The tubing will be run through a peristaltic pump, then to a flow cell to which a multi- parameter AquaTroll 500 meter will be attached, and finally to a 5-gallon bucket to collect the purge water. The initial water level would be measured in the monitoring well only and recorded prior to the initiation of pumping. Once pumping is initiated, water levels, pumping rate, cumulative volume purged, water temperature, specific conductivity, pH, oxygen reduction potential (ORP), dissolved oxygen (DO), and turbidity will be recorded at three to five-minute intervals until either stabilization is achieved or the monitoring well pumps dry. Pumping rates will be maintained at rates of 50 to 200 milliliters per minute to minimize drawdown. Stabilization is defined as three consecutive measurement intervals where temperature and specific conductivity were +/- 3%, pH was +/- 0.1, DO was +/-10% (or less than 0.5 mg/L), and turbidity was +/- 10% (or less than 5 nephelometric turbidity units [NTUs]). If the monitoring well pumps dry, it will be allowed to recharge to a minimum of at least 90% of its static water level prior to sampling. After stabilization is achieved, the tubing would be disconnected from the flow cell and the groundwater sample would be dispensed into appropriate laboratory prepared containers. Groundwater samples would be collected into appropriate containers with gloved hands and transported under chain-of-custody, in an iced cooler to Chemtech-Ford Laboratories (CF) for analysis of VOCs using U.S. EPA Method 8260D, dissolved arsenic (this sample will be filtered in the field using a 0.45-micron filter prior to dispensing the sample into the laboratory preserved/supplied container) using U.S. EPA Method 6010B, and SVOCs using U.S. EPA Method 8270E. 4.2 On-Site Additional Boring Sampling This boring will be installed using the direct-push drilling methods. Soil core samples would be continuously collected from 5-foot long by 1.5-inch diameter discrete interval push samplers equipped with disposable polybutyrate liners. Soil samples would be collected continuously and field logged by an experienced geologist. The field logging would include a description of color, moisture content, consistency, odor, staining, and soil type based on the Unified Soil Classification System and screened in the field with a PID. Two soil boring samples will be collected from this boring, one from the upper 3 feet and a second at the approximate vadose zone / saturation zone interface. Subsequent to the boring, a stainless-steel temporary well screen will be placed within the groundwater to collect a groundwater sample. Groundwater would be purged from the boring in an attempt to reduce the turbidity of the groundwater sample. Groundwater and soil samples would be collected into appropriate containers with gloved hands and transported under chain-of-custody, in an iced cooler to CF for analysis of arsenic in soil and dissolved arsenic (the groundwater sample will be filtered in the field using a 0.45-micron filter prior to dispensing the sample into the laboratory preserved/supplied container) using U.S. EPA Method 6010B. Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 8 4.3 Off-Site Groundwater Sampling These borings will be installed using the direct-push drilling methods. Soil core samples would be continuously collected from 5-foot long by 1.5-inch diameter discrete interval push samplers equipped with disposable polybutyrate liners. Soil samples would be collected continuously and field logged by an experienced geologist. The field logging would include a description of color, moisture content, consistency, odor, staining, and soil type based on the Unified Soil Classification System and screened in the field with a PID. Subsequent to the borings, a stainless-steel temporary well screen will be placed within the groundwater to collect a groundwater sample. Groundwater would be purged from the boring in an attempt to reduce the turbidity of the groundwater sample. Groundwater samples would be collected into appropriate containers with gloved hands and transported under chain-of-custody, in an iced cooler to CF for analysis of VOCs using U.S. EPA Method 8260D and SVOCs using U.S. EPA Method 8270E. Given that the adjoining west property owners may reject our request to collect groundwater samples from their property. These borings may not be collected. Wasatch will provide proof of acceptance or rejection of our request to sample the adjoining west property. 4.4 Indoor Air Sampling To evaluate potential soil vapor intrusion impacts in the on-Site building, Wasatch would collect six indoor air samples, four within the warehouse/manufacturing area (IA-1 through IA-4) on the ground floor level and two in the office areas (IA-5 and IA-6), and one outdoor air sample (OA-1) to be used as a background sample. Proposed sample locations are shown in Figure 2. Prior to collecting any indoor or outdoor air samples, Wasatch would complete a chemical inventory of the interior of the building space at the Site. This would be done to verify that no products within the structure contain any chemicals of concern. If products are found that contain the same chemicals of concern we will be analyzing for, those products will be removed from the building for at least 7 days prior to sampling. This will be completed to reduce the potential for false positives within the indoor air samples. Wasatch would also interview the appropriate personnel to ascertain if potential activities within the beginning have been conducted that may result in false positives (i.e. recent remodeling, floor stripping, etc.) The technique for collecting the indoor/outdoor air samples would begin by checking for a vacuum in each 6-liter Summa canister supplied by the laboratory. The initial vacuum would be recorded on the chain-of- custody form. A 6-liter Summa canister would then be placed at an appropriate height for each sample location. The sampling location height will generally be placed at breathing space height. A sample regulator with a flow restrictor would be provided by the laboratory. A sample regulator would be attached to each 6-liter Summa canister. The vacuum gauge on the flow restrictor would be monitored, with decreasing vacuum indicating that ambient indoor air is being collected into the sample canister. The samples would be collected for approximately 8 hours to represent a standard workday. The final vacuums would be recorded on the chain-of-custody form provided. The valve on each Summa canister would then be closed, the sample regulator would be removed, and a brass cap tightened to the inlets of the Summa canisters. The Summa canisters would be labeled with the appropriate sample location, as well as initial and final vacuum reading. Chain-of-custody documentation would be completed and the samples would be delivered to Pace Analytical (Pace) for the analysis of the standard list of VOCs using U.S. EPA Method TO-15. The laboratory will use level 3 quality assurance/quality control (QA/QC) reporting. A Data Validation Report will be completed by an independent third-party for the groundwater, indoor air, and outdoor air sample samples. Arms Technology East Shop Additional Investigation Work Plan Project No. 2619-004C Wasatch Environmental, Inc. Page 9 5. REPORTING All data generated during the sampling will be documented in a final report. This report will include the following:  Narrative text,  Data table,  Boring/well construction logs,  Applicable maps,  Chain of custody forms,  Laboratory analytical results, and  Third-party data validation report. The results of the sampling and analysis will be summarized in the report. Data will be presented in table format. Conclusions based on the data as well as field observations will be included in the report. After the laboratory data has been received, and reviewed, the report will be completed and submitted to ATI Corporation prior to submission to the Utah DWMRC. Sincerely, WASATCH ENVIRONMENTAL, INC. Blake Downey, P.G. Vice President and Senior Project Hydrogeologist Distribution: (1) Electronic - Addressee (1) Electronic – Scott Farber (ATI Corporation) The use or reuse of this information is restricted to the referenced document unless otherwise authorized. Wasatch Environmental Copyright 2006 ARMS TECHNOLOGY EAST SHOP WEI 2619-004C Figure 1 Site Location Map Approximate Location of Site The use or reuse of this information is restricted to the referenced document unless otherwise authorized. Wasatch Environmental Copyright 2006 ARMS TECHNOLOGY EAST SHOP WEI 2619-004C Historical and Proposed Sample Location Map Figure 2 Approximate Location of Site 24 7 5 W es t Storm water lift station Totes of coolant Sump and drain pad Shoot tunnel Sump Parts washer SG-1 SG-3 SG-4 SG-2 SG-5 SG-6 GP-2 GP-1 GP-7 GP-5 GP-3 GP-6 GP-4 Previous Boring Location Previous Soil Gas Sample Location LEGEND GP-8 GP-9 GP-10 GP-11 GP-12 GP-13GP-14 GP-15 GP-16 GP-17 GP-18 Proposed Monitoring Well Location MW-3 MW-4 MW-2 MW-1 MW-5 MW-6 Proposed Indoor/Outdoor Air Sample Location IA-3 IA-4 IA-5 IA-2IA-1 IA-6 OA-1 Scale: 1-inch equals approximately 51 feet Assumed Groundwater Flow Direction GP-21 GP-20 Proposed Boring Location MW-7 GP-19 The use or reuse of this information is restricted to the referenced document unless otherwise authorized. Wasatch Environmental Copyright 2006 ARMS TECHNOLOGY EAST SHOP WEI 2619-004C Groundwater Exceedance Map Figure 3 Approximate Location of Site 24 7 5 W es t GP-4 Boring Location *All concentrations are reported in micrograms per liter, unless otherwise noted. **All concentrations in exceed the U.S. EPA MCL.red GP-2 TCE - 21.3 41.5PCE - 106CIS - GP-1 Arsenic - 90.3 10.0 ng/LPFOS - GP-3 TCE - 23.2 134PCE - GP-5 TCE - 72.8 371PCE - 78.7Arsenic - GP-7 TCE - 288 2,190PCE - 243Arsenic - GP-6 TCE - 254 2,450PCE - 87.5Arsenic - 1-inch equals 50 ft. GP-8 TCE - 1,170 6,060PCE - 25.6Arsenic - GP-9 TCE - <1,000 13,200PCE - 17.5Arsenic - GP-10 TCE - 65.0 765PCE - 39.5Arsenic - GP-11 TCE - 23.9 45.8PCE - GP-12-15 TCE - 951 4,770PCE - 101Arsenic - GP-12-30 TCE - 116 641PCE - GP-13-15 TCE - 62.4 266PCE - 320Arsenic - 82.2CIS - GP-13-30 TCE - 5.87 30.2PCE - GP-14 TCE - 39.5 177PCE - GP-15 TCE - 5.67 23.3PCE - GP-16 TCE - 183 1,210PCE - GP-17-15 TCE - 230 1,310PCE - 267Arsenic - 109CIS - GP-17-30 TCE - 42.2 195PCE - GP-18 TCE - 307 1,640PCE - The use or reuse of this information is restricted to the referenced document unless otherwise authorized. Wasatch Environmental Copyright 2006 ARMS TECHNOLOGY EAST SHOP WEI 2619-004C Soil Gas Exceedance Map Figure 4 Approximate Location of Site 24 7 5 W es t Storm water lift station Totes of coolant Sump and drain pad Shoot tunnelSump Parts washer Soil Gas Sample Location *All concentrations are reported in micrograms per cubic meter. **All concentrations in exceed the U.S. EPA VISLred Commercial TSSGC. SG-1 TCE - 4,400 82,000PCE - SG-2 TCE - 2,100 43,000PCE - SG-3 TCE - 1,500 48,000PCE - SG-4 TCE - 15,000 150,000PCE - SG-5 TCE - 8,200 110,000PCE - SG-6 TCE - 270 5,000PCE - 1-inch equals 50 ft.