ATTACHMENT 08 - XGFG182009 F-35 Alter B400 AMXS - Site Characterization Report.pdf

Site Characterization Report

Wisconsin Air National Guard Air Fighter Wing Facility F-35 Bed Down - W50S9F20F0002

XGFG182006

XGFG182009

XGFG192006

XGFG182017

XGFG192002

XGFG192005

XGFG182018

Truax Field Madison, Wisconsin

Prepared for:

FRANKFURT-SHORT-BRUZA

ASSOCIATES, P.C. (FSB)

5801 Broadway Extension, Suite 500 Oklahoma City, OK 73118

December 2020

1139530876N Highlight

5201 E. Terrace Drive, Suite 200 Madison, WI 53718

608.443.1200 • Fax: 608.299.2184 www.AyresAssociates.com

Ayres Project No. 51-0467.10 File: \\ayres\_Active\51\MD\00-51-0467 WIANG_Bed Down Project\Additional Truax Sites Project\Site

Characterization Report\Final Report\201209R.docx

Wisconsin Air National Guard Air Fighter Wing Facility

F-35 Bed Down - W50S9F20F0002

XGFG182006

XGFG182009

XGFG192006

XGFG182017

XGFG192002

XGFG192005

XGFG182018

Truax Field Madison, Wisconsin

This report prepared by:

Jeffrey C Steiner, PG, PH, CPG Senior Hydrogeologist

This report reviewed by:

Thomas Gaieck, PG Hydrogeologist

Note: Report truncated to reflect project.

Questions are to be directed to KO or COR.

i

Contents Page No.

Executive Summary Introduction Background

Site Location and Description Site History and Background Recognized Environmental Concerns

Regional Geology and Hydrogeology Geology Hydrogeology

Site Conceptual Model Site Geology and Hydrogeology

Site Stratigraphy Groundwater Flow Conditions

Groundwater Levels Groundwater Flow Vertical Gradients Hydraulic Conductivity Testing Groundwater Flow Velocity

Soil Quality Assessment Field Observations and Screening Results Results of Soil Sample Laboratory Analysis

Per-and Polyfluorinated Alkyl Substances (PFAS) Volatile Organic Compound Analysis (VOC)

Groundwater Quality Assessment Per-and Polyfluorinated Alkyl Substances (PFAS) Volatile Organic Compound Analysis (VOCs) Field Parameters

Building Materials Assessment Vapor Assessment Summary of Findings

Geology and Hydrogeology Soil Assessment

Per-and Polyfluorinated Alkyl Substances (PFAS) Volatile Organic Compound Analysis (VOCs)

Groundwater Assessment ii

Per-and Polyfluorinated Alkyl Substances (PFAS) Volatile Organic Compound Analysis (VOCs)

Vapor Assessment Recommendations References

List of Figures

Figure 1 – Site Location Map Figure 2 – Soil Probe and Monitoring Well Location Map Figure 3 - Geologic Cross Section A-A" Figure 4 - Water Table Contour Map Figure 5 - Summary of PFAS Detections and Exceedances in Groundwater Figure 6 - Summary of VOC Detections and Exceedances in Groundwater

List of Tables

Table 1 - Summary of Groundwater Elevation Data Table 2 - Summary of Hydraulic Conductivity Test Results Table 3 - Summary of Soil Sample Laboratory Analytical Results - PFAS Table 4 - Summary of Groundwater Analytical Results - PFAS Table 5 - Summary of Groundwater Analytical Results - VOC Table 6 - Water Quality Field Parameter Data

List of Appendices

Appendix A - Geologic Logs and Monitoring Well Construction and Development Forms

Appendix B - Hydraulic Conductivity Test Results

Appendix C - Laboratory Analytical Reports for Soil Samples

Appendix D - Low Flow Sampling Stabilization Logs Appendix E - Laboratory Analytical Reports for Groundwater Samples

Appendix F - Soil and Groundwater Sample Laboratory Analytical Results by Site

See "Material Management Plan PFAS" See "Material Management Plan PFAS"

See "Material Management Plan PFAS"

Not Applicable Not Applicable

Not Applicable

Not Applicable See "Material Management Plan PFAS"

See "Material Management Plan PFAS" Not Applicable

Data Highlighted

Data Highlighted

Data Included

Not Applicable

See "Material Management Plan PFAS"

See "Material Management Plan PFAS"

Data Included

Data Included

Executive Summary Frankfurt-Short-Bruza Associates, P.C. (FSB) was retained by the Wisconsin Air National Guard (WIANG) to upgrade their installation to accommodate the F-35A aircraft including the construction of ALERT parking garages and munitions maintenance and inspection facility, repair of existing structures, and installation of a new perimeter fence. Ayres Associates partnered with FSB on the project to provide environmental services including assessment of soil and groundwater for previously documented volatile organic compounds (VOC) and per-and polyfluorinated alkyl substances (PFAS). The purposes of this scope of work are to assess and characterize potential environmental impacts that may exist at the subject property and obtain information required to prepare a materials management plan for site development.

Unconsolidated sediments at the site consist of natural fill materials and stratified layers of ground moraine and lake plain deposits to the depth of exploration at 15 feet. The sediments consist of fine-grained silty sand, clayey sand, silt, and low plasticity clay deposits of low to medium permeability overlying fine to coarse-grained, poorly graded sand and gravel materials of medium to high permeability.

Bedrock in the site area is estimated to be over 300 below ground surface.

Depth to water ranged from 5.16 feet below the top of well casing in well 01-AA-MW-3 to 8.38 feet in well 04-AA-MW-9. The water table was found at or slightly above the interface of the two hydrostratigraphic units (i.e., clay/sand unit interface). Groundwater flow in the shallow unconsolidated deposits was generally northwest across the site at an average horizontal hydraulic gradient of 0.001. The average horizontal groundwater flow velocity in the unconsolidated water table aquifer across the subject site is approximately 0.39 feet/day or 142 feet/year.

Per-and Polyfluorinated Alkyl Substances (PFAS) were detected in 29 of the 34 soil samples submitted for PFAS analysis. Trace concentrations of perfluorooctanesulfonic acid (PFOS) were detected in 28 of the soil samples analyzed while perfluorooctanoic acid (PFOA) was detected in 7 of the soil samples analyzed. None of these constituents exceeded their respective regulatory standards in soil samples analyzed during this assessment. Results of lab analysis show none of the soil samples analyzed had detectable levels of VOC.

Detectable concentrations of PFAS compounds were found in each of the nine groundwater samples analyzed. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations exceeded the NR 140 Wisconsin Administrative Code enforcement standard of 0.02 μg/L, as well as the USEPA Health Advisory of 0.07 μg/L in samples collected from 6 wells and 9 wells, respectively.

Laboratory results indicate detectable concentrations of VOC constituents in samples collected from four of the nine monitoring wells. Most of the petroleum and chlorinated hydrocarbon (VOC) constituents detected were found in samples collected from wells 01-AA-MW-2, 01-AA-MW-3, and 01-AA-MW-4 where olfactory observations during well development indicated the likely presence of hydrocarbons.

Concentrations of 1,2-dichloroethane, benzene, and bromodichloromethane exceeded their respective NR 140 Wisconsin Administrative Code enforcement standards (ES) in a sample from well 01-AA-MW-3.

Bromodichloromethane also exceeded the ES in a sample from well 01-AA-MW-4. The constituents 1,1,2-trichloroethane, 1,2,4-trimethylbenzene, 1,2-dichloropropane, benzene, bromodichloromethane, and naphthalene exceeded their respective NR 140 Wis. Adm. Code preventive action limits (PAL) in samples from one or more monitoring well.

A qualitative vapor assessment was performed during this assessment. Ayres Associates concludes that residual hydrocarbon contamination in soil and groundwater is not of sufficient concentration to be a concern from vapor migration or intrusion in existing or future utilities and buildings.

Soil and groundwater and building materials at the site will require proper handling and management during construction in accordance with an approved Materials Management Plan.

Introduction Frankfurt-Short-Bruza Associates, P.C. (FSB) was retained by the Wisconsin Air National Guard (WIANG) to upgrade their installation to accommodate the F-35A aircraft including the construction of ALERT parking garages and munitions maintenance and inspection facility, repair of existing structures, and installation of a new perimeter fence. The six separate project sites and perimeter fence associated with F35: Bed Down project include:

01 - XGFG182017 – Munitions Maintenance and Inspection Facility 02 - XGFG182009 – F35 Alter B400 AMXS Building 03 - XGFG182006 – Alert GOV Parking shelters 04 - XGFG192002 – F35 Repair B401 AGE Building 05 - XGFG182018 - F35 Repair B1207 06 - XGFG192005 – F35 Repair B511 HAZMAT 07 - XGFG192006 – Perimeter Fence

Ayres Associates partnered with FSB on the project to provide environmental services including assessment of soil and groundwater for previously documented volatile organic compounds (VOC) and per-and polyfluorinated alkyl substances (PFAS). These compounds were detected during previous environmental investigations conducted at the site. The presence of VOC compounds in soil and groundwater are associated with the use and storage of petroleum and other hazardous substances at the installation. The PFAS contamination detected at the site is attributed to the storage and use of firefighting foams at Hangar 414 and other nearby buildings or firefighting equipment testing areas at the base.

The Wisconsin Department of Natural Resources (WDNR) required confirmation of VOC and PFAS concentrations in soil and groundwater at the site and submittal of a Materials Management Plan (MMP) based upon the results of this assessment. In addition to the subsurface investigation and preparation of a materials management plan, a survey of building materials was conducted so that potential asbestos, lead-bearing paint, and other potentially hazardous materials are identified for proper removal prior to demolition or renovation. Therefore, the scope of work performed included evaluation and analysis of existing environmental data, soil sampling in the unsaturated zone, installation of temporary monitoring wells, collection of soil, groundwater, asbestos, and lead paint samples, and laboratory analysis of the environmental samples. Proposed sample locations include areas of known or suspected impacts based on historical information obtained from the WDNR Bureau of Remediation and Redevelopment Tracking System (BBRTS) on the Web and the “Draft Report, FY 16 Phase I Regional Site Inspections for Perfluorinated Compounds (March 2018), prepared by Amex Foster Wheeler under contract to the

WIANG.

A Site Characterization Investigation was conducted at the six sites and perimeter fence area in October 2020. The primary objectives of the investigation were to:

Define the local geology including the origin, texture, thickness, and distribution of the unconsolidated deposits Determine the local hydrogeologic conditions including depth to groundwater, and groundwater flow directions and gradients Confirm the type and distribution of contaminants of concern in the soil and groundwater at these sites Evaluate potential contaminant pathways and the potential for migration in soil and groundwater

Use data collected during this assessment and assessments completed by others to prepare a materials management plan to manage potentially impacted environmental media during construction.

Environmental assessment and management activities related to site development are the subjects of this report.

Background

Site Location and Description

The project site is located in the Northeast ¼ of the Northwest ¼ of Section 29, Township 8 North, Range 10 East, Dane County, Wisconsin. The site (herein referred to as site or property) is located at Truax Field, 3200 Pierstorff Street, Madison, Wisconsin (Figure 1).

With the recent announcement that the base will be transitioning to F-35A aircraft, several buildings and engineering appurtenances will require replacement or retrofitting to accommodate the new mission.

Site History and Background

The history of the site was obtained from environmental reports obtained from the WDNR BRRTS on the Web and from the “Draft Report, FY 16 Phase 1 Regional Site Inspections for Perfluorinated Compounds (March 2018), prepared by Amec Foster Wheeler under contract to the WIANG.

The WIANG installation at Truax Field was originally constructed in 1942 as an Army base. The base was deactivated as an active military base in 1968 when it became occupied by the WIANG. Since 1942, fighter/attack aircraft have been housed at Truax Field. Over the years, the installation has used and stored petroleum and other hazardous materials.

The Department of Defense has conducted environmental investigations at military bases across the county as part of the Installation Restoration Program. The WIANG base at Truax Field was one of the facilities included in the program. According to the WDNR BRRTS, environmental activities have been conducted on the site since 1990 when a preliminary facility investigation indicated soil and groundwater in proximity to Hangar 414 was impacted by petroleum. A subsequent investigation conducted by Dames and Moore defined an area of soil and groundwater contamination that resulted in the excavation and disposal of petroleum-contaminated soil and operation of a soil vapor extraction system (SVE). The site was closed by the WDNR in 2012 with residual soil and groundwater contamination.

A Perfluorinated Compound Preliminary Assessment Site Visit was conducted on the base by BB&E, Inc.

in 2015. The purpose of the visit was to identify sites with potential perfluorinated compound releases associated with Aqueous Film Forming Foam (AFFF) use and storage. The results of the assessment are documented in the “Final Perfluorinated Compounds Preliminary Assessment Site Visit Report (December 2015) prepared by BB&E, Inc. Findings of the report concluded that Hangar 414 was equipped with a fire suppression system supplied with AFFF and that a site investigation of soil and groundwater was recommended.

A Phase 1 Regional Site Inspection for Perfluorinated Compounds was conducted at the base by Amec Foster Wheeler in 2017. This work included subsurface investigation of soil and groundwater for perfluorinated compounds based upon the recommendations of the 2015 BB&E Site Visit Report. Three soil boring were advanced at the Hangar 414 site for collection of six soil samples. Soil samples were collected from the 0.5’-1’ interval and just above the water table at a depth of 4.5’ to 5.5’. One temporary well was also installed for collection of one groundwater sample. Results of soil sample analysis indicated detectable perfluorinated compound concentrations. However, none of the compounds detected in soil exceeded the screening criteria. Groundwater analysis detected six perfluorinated compounds with two compounds exceeding the EPA Drinking Water Health Advisory.

Recognized Environmental Concerns

Environmental concerns regarding the sites are related to the known VOC contamination discovered during environmental activities conducted in the 1990s by Dames and Moore and others. The BRRTS site related to this contamination is closed with inclusion on the GIS registry indicating residual soil and groundwater contamination. A more recent site investigation conducted on the site by Amec Foster and Wheeler and Ayres Associates detected per- and polyfluorinated alkyl (PFAS) substances in soil and groundwater at the site.

Several buildings at the site are scheduled for demolition or retrofitting to accommodate F-35A aircraft.

Based upon the age of the buildings, asbestos and lead-bearing paint may be present in the building materials, and asbestos and lead-bearing paint inspections were conducted.

Regional Geology and Hydrogeology

Geology

Evaluation of the site geology is based on existing published regional information1, and site-specific data collected from borings advanced in the project area. Subsurface information collected during previous assessment activities conducted on the site indicates that the unconsolidated sediments consist primarily of between 3 and 7 feet of clay and silty clay underlain by fine to medium-grained sand to a depth of at least 18 feet below ground surface (bgs).

Regional information indicates that surficial unconsolidated deposits consist of glacial ground moraine and lake plain sediments consisting of stratified layers of sand, silt, and clay. Information obtained by the author of this report from a site investigation performed in 1992 for the City of Madison at the Truax Landfill located southwest of the project site indicates a deep, pre-glacial bedrock valley running beneath the Truax Regional airport and project site. The unconsolidated deposits in the bedrock valley beneath the site area are estimated to be over 300 feet thick. The uppermost bedrock unit beneath the site is the Cambrian age Mount Simon Sandstone.

Hydrogeology

Groundwater is found within the unconsolidated glacial deposits and underlying sandstone bedrock.

These aquifers are the source for domestic, municipal, and industrial water supplies in the Madison area and Dane County. The bedrock aquifer is the principal source of municipal water in Dane County. The City of Madison uses wells completed in the Mount Simon sandstone for its municipal water supply. Truax Field is supplied water from the City of Madison distribution system.

Depth to groundwater is less than ten feet below ground surface. Previous investigations at the site indicate that shallow groundwater has been interpreted to flow south-southeast.

Site Conceptual Model

A site conceptual model is a preliminary evaluation and description of the natural environment that exists at the site, including hydrogeologic conditions, potential contamination sources, contaminant release mechanisms and migration routes, potential human and ecological receptors that may come in contact with contaminants, and potential exposure pathways. The conceptual model is based on existing published information or knowledge of a site and provides a preliminary framework for planning and implementing site characterization activities.

Based on existing information, the anticipated site stratigraphy in the project area will consist of clay and silty clay overlying fine to medium-grained sand with gravel to the depth of exploration.

Depth to groundwater is anticipated to be within five feet of ground surface. Recharge to the upper aquifer system is likely through direct infiltration of precipitation and snowmelt. Discharge from the shallow aquifer system likely occurs by evapotranspiration and seepage into Starkweather Creek. Groundwater flow in the shallow water table is interpreted to be northwest (or southeasterly depending on location), based on previous investigations performed at the site.

Environmental impacts to be investigated at this site, based on information from the Wisconsin Department of Natural Resources (WDNR) and the Wisconsin Air National Guard (WIANG) include

1 Clayton, Lee and Attig, J.W. 1997. “Pleistocene Geologic Map of Dane County, Wisconsin, WGNHS Bulletin 95, Plate 1.

volatile organic compounds (VOC) and Per- and Polyfluorinated Alkyl Substances (PFAS) in soil and groundwater. These compounds have been detected during previous investigations conducted at the site.

Likely contaminant release mechanisms and exposure routes include direct contact and ingestion threats from impacted soil by on-site workers and off-site migration of contaminated groundwater. Infiltration of precipitation may also transport contaminants from the soil into the groundwater; impacted groundwater could potentially be discharged to storm sewers and Starkweather Creek.

Results obtained from this limited assessment generally conform to the site conceptual model. Depth of groundwater was slightly deeper at six to eight feet below ground surface than the less than five below ground surface anticipated. Trace concentrations of PFAS were detected in soil samples collected at the site and PFAS concentrations in some groundwater samples exceeded regulatory levels. VOC constituents were not detected in soil samples but were detected above regulatory levels in some groundwater samples during this site characterization project. Surface water samples were not collected for this project.

Site Geology and Hydrogeology

Site Stratigraphy

Subsurface conditions were evaluated based on information collected from twenty-five (25) soil probes advanced to a maximum depth of 15 feet below ground surface (bgs) during this assessment. Probe depths were terminated at 10 feet bgs instead of 15 feet bgs as indicated in the work plan due to shallow groundwater, except for probes 03-AA-MW-6 and 04-AA-MW-9. Soil probes 03-AA-MW-6 and 04-AA- MW-9 were advanced to 15 feet bgs due to deeper water levels at these locations and to obtain additional hydrogeologic information at depth in case dewatering is required. Soil probe 02-AA-MW-2 was relocated from Site 2 (Alter B400 building) to Site 1 (Munitions Maintenance and Inspection Facility) at the direction of Truax personnel and relabeled 01-AA-MW-4. Nine of the 25 soil probes advanced were used for the installation of temporary monitoring wells. Locations of the probes and temporary monitoring wells are shown in Figure 2. Geologic cross-section A-A’ is shown in Figure 3. Geologic boring and well construction logs are presented in Appendix A.

Subsurface information collected during this assessment indicates the unconsolidated sediments at the site consist of natural fill materials and stratified layers of ground moraine and lake plain deposits to the depth of exploration at 15 feet. The unconsolidated sediments are presented as two hydrostratigraphic units on cross-sections A-A’ based on similar hydrologic characteristics such as grain size and permeability. The top unit consists of finer-grained silty sand, clayey sand, silt, and low plasticity clay deposits of low to medium permeability. The lower hydrostratigraphic unit consists of fine to coarse-grained, poorly graded sand and gravel materials of medium to high permeability.

Bedrock was not encountered during this assessment. Depth to bedrock in the site area is estimated to be over 300 below ground surface.

Groundwater Flow Conditions

Groundwater Levels

Groundwater level and elevation data were obtained from the monitoring wells on October 7 and October 8, 2020 (Table 1). Water level data collected on October 8th indicate that depth to water ranged from 5.16 feet below the top of well casing in well 01-AA-MW-3 to 8.38 feet in well 04-AA-MW-9. Water levels were

0.03 to 0.58 feet (0.36 to 6.9 inches) lower in each of the five wells measured on October 7, 2020. The water table was encountered at or slightly above the interface of the two hydrostratigraphic units (i.e., clay/sand unit interface).

Groundwater Flow

Water level data obtained from the temporary monitoring wells on October 8, 2020, were used to construct a water table contour map (Figure 4). Groundwater flow in the shallow unconsolidated deposits was generally northwest across the site during the October 2020 sampling event at an average horizontal hydraulic gradient of 0.001. The groundwater flow direction and gradient are consistent with results for the site characterization performed at the nearby hangar 414 building site in June 2020.

Vertical Gradients

Differences in the hydraulic head can occur between different geologic units. The difference in the hydraulic head is caused by steep hydraulic gradients induced by heavy groundwater pumping, large topographic relief, or by differences in hydraulic conductivity. Vertical gradients can induce or prevent contaminant migration in and between aquifers depending on the magnitude and direction of the gradient.

Vertical gradients could not be calculated as no well nests were installed during this assessment.

Hydraulic Conductivity Testing

Hydraulic conductivity (slug) tests were not performed on the nine temporary monitoring wells installed at the site during this assessment. However, slug tests were performed on four of the monitoring wells installed at the nearby Hangar 414 site during the June 2020 assessment performed by Ayres Associates. Those results are included in this report as the tests were performed on wells screened in the same geologic materials as the wells installed for this assessment.

The tests were performed by inserting a solid cylinder (slug) into the well and allowing the water level to equilibrate. The slug was then rapidly removed from the well to cause an instantaneous drop in water level (rising head test), then measuring the return of the water level to its static condition. Water level data were recorded with an automated pressure transducer and data logger system. Slug test data were evaluated using Aqtesolv v. 4.5 graphical analysis and reporting software. The slug tests were analyzed using the methods of Bouwer and Rice (1976) for unconfined aquifers.2 Results of the slug tests are shown in Table 2. Test parameters and curves from the June 2020 assessment are presented in Appendix B.

Hydraulic conductivity values (recovery test only) calculated for the four temporary monitoring wells tested in June 2020 ranged from 2.4 x 10-2 cm/sec to 7.1 x 10-2 cm/sec. Each well was screened mostly or entirely within the coarse-grained sand and gravel layer beneath the site.

Groundwater Flow Velocity

Groundwater flow velocity was calculated for the water table aquifer at this site using the formula:

V = ki/ne

Where:

V = horizontal groundwater flow velocity k = hydraulic conductivity i = hydraulic gradient ne = effective porosity

An average hydraulic conductivity value of 4.1 x 10-2 cm/sec was used in calculating groundwater flow velocity in the water-table aquifer. This value was obtained by calculating the arithmetic mean of hydraulic conductivity results for tests performed on water table wells at the site.

The hydraulic gradient (i) used to calculate horizontal groundwater flow velocity is based on water levels measured on October 8, 2020. An average horizontal gradient of 0.001 ft/ft was used to calculate groundwater flow in the upper unconsolidated aquifer.

The velocity of groundwater is also influenced by the porosity of the aquifer material. The effective porosity (ne) is a measure of the amount of interconnecting pore space that is available in a given volume

2 Bouwer, H. and R.C. Rice, A Slug Test for Determining Hydraulic Conductivity of Unconfined Aquifers with Completely or Partially Penetrating Wells, Water Resources Research, Vol.12, No.3, 1976, pp.423-of material through which water can move. The average effective porosity of the unconsolidated material is assumed to be 30 percent.

Based on the values stated above, the average horizontal groundwater flow velocity in the unconsolidated water table aquifer across the subject site is approximately 0.39 feet/day or 142 feet/year.

Soil Quality Assessment Soil samples were collected from the twenty-five soil probes advanced during the assessment and submitted to CT Laboratories in Baraboo, Wisconsin, for analysis. Selected samples were analyzed for VOC and PFAS; Vista Analytical was contracted by CT Labs to analyze for PFAS. The locations of the proposed borings and wells, and the depth of sampling, were prescribed by the WDNR and WIANG based upon previous site assessment findings completed by others as discussed in the WDNR-approved Sampling and Analysis Plan. Soil samples collected from nine of the probe locations at the six-building sites were generally selected for laboratory analysis from the 1-2-foot depth interval and the interval approximately one-foot above the water table. Soil samples collected from the remaining 16 soil probe locations advanced along the perimeter fence were selected from the 0-2-foot depth interval. Within those prescribed intervals, the soil sample with the highest PID readings at each sampling location was selected for laboratory analysis. If no volatile organic contamination was identified above background during field screening, a sample from each sampling location was selected based on obvious discoloration or other visible signs of contamination. Soil samples were submitted to the laboratory and analyzed for PFAS and VOC using Vista’s PFAS Isotope Dilution Method and EPA Method 8260C, respectively.

Field Observations and Screening Results

Headspace analysis was performed on each of the soil samples obtained from the probes. Headspace analysis is a screening tool used to qualitatively assess the degree of potential impacts to soil from volatile organic compounds. The headspace analysis was performed using a photoionization detector (PID) equipped with an 11.7 eV lamp in accordance with Ayres Associates’ standard operating procedure #210. Headspace analysis results are shown on the boring logs in Appendix A.

Results of the headspace analysis do not indicate the potential presence of elevated levels of volatile organic constituents in the soil samples collected from above the water table in any of the probes advanced during this assessment. However, elevated PID readings of 322 and 1097 instrument units (IU) were recorded for soil samples collected at or below the water table from probe 01-AA-MW-1 at 5 feet and 8 feet below ground surface respectively, where a moderate to strong hydrocarbon odor was observed. A slight hydrocarbon odor was also noted in a soil sample collected below the water table in probe 01-AA-MW-4 with a corresponding PID reading of 5.6 IU.

Results of Soil Sample Laboratory Analysis

Thirty-four (34) soil samples collected from the soil probes advanced during this assessment were submitted for analysis. Samples were analyzed for VOCs and PFAS. VOCs were analyzed using EPA Method 8260C and PFAS was analyzed using Vista’s PFAS Isotope Dilution Method. A summary of analyte detections in soil is presented in Table 3. Laboratory data reports for soil samples are presented in Appendix C.

Per-and Polyfluorinated Alkyl Substances (PFAS)

Per-and Polyfluorinated Alkyl Substances (PFAS) were detected in 29 of the 34 soil samples submitted for PFAS analysis. Trace concentrations of perfluorooctanesulfonic acid (PFOS) were detected in 28 of the soil samples analyzed and one equipment blank. Trace concentrations of perfluorooctanoic acid (PFOA) were detected in only 7 of the soil samples analyzed. The parameters PFOS and PFOA are the only two PFAS constituents that have established regulatory standards for soil in Wisconsin. Neither of these constituents exceeded their respective regulatory standards in any of the soil samples analyzed during this assessment.

Volatile Organic Compound Analysis (VOC)

Each of the 34 soil samples collected was analyzed for volatile organic compounds (VOC). All soil samples were collected from above the water table. Results of lab analysis show none of the soil samples analyzed had detectable levels of VOC; therefore, the results of VOC analysis were not tabulated. See the lab data sheets in Appendix C for a complete list of VOC constituents analyzed.

Groundwater Quality Assessment Groundwater samples were collected from each of the nine monitoring wells installed at the project site.

The purpose of this sampling is to characterize the nature and extent of potential contamination at the site by determining the type, distribution, and concentration of chemical constituents present in the groundwater. The analytical data will also be used to evaluate potential treatment or disposal options for groundwater should dewatering be required during construction.

Ayres Associates collected one round of groundwater samples from the nine monitoring wells. Samples were collected from the wells on October 8, 2020, and submitted to CT Laboratories in Baraboo, Wisconsin for analysis of VOCs. Samples for PFAS analysis were submitted to Vista Analytical, a subcontractor of CT Labs. Each of the groundwater samples was analyzed for VOC and PFAS. VOCs were analyzed using EPA SW-846 Method 8260C and PFAS were analyzed using Vista’s PFAS Isotope Dilution Method. A summary of PFAS detections in groundwater is presented in Table 4. Analytical results for VOC analyses are presented in Table 5. Low-flow stabilization data are presented in Appendix D and laboratory datasheets for the groundwater sampling event are presented in Appendix E. The location of analyte detections and exceedances for PFAS and VOC in groundwater are shown in Figure 5 and Figure 6, respectively. Appendix F contains soil and groundwater results tabulated by the site for convenient reference.

Per-and Polyfluorinated Alkyl Substances (PFAS)

Each of the nine groundwater samples collected was submitted for PFAS analysis. Detectable concentrations PFAS compounds were found in each of the nine groundwater samples analyzed and one equipment blank. (Note: trace concentrations of POFSA was the only parameter found in the equipment blank). Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations exceeded the NR 140 Wisconsin Administrative Code enforcement standard of 0.02 μg/L, as well as the USEPA Health Advisory of 0.07 μg/L in samples collected from 6 wells and 9 wells, respectively. The parameters PFOS and PFOA are the only two PFAS constituents that have established groundwater regulatory standards in Wisconsin.

Volatile Organic Compound Analysis (VOCs)

Groundwater samples collected from each of the nine temporary monitoring wells were analyzed for volatile organic compounds (VOC). Laboratory results indicate detectable concentrations of VOC constituents in samples collected from four of the nine monitoring wells. Most of the petroleum and chlorinated hydrocarbon (VOC) constituents detected were found in samples collected from wells 01-AA- MW-2, 01-AA-MW-3, and 01-AA-MW-4 where olfactory observations during well development indicated the likely presence of hydrocarbons. Concentrations of 1,2-dichloroethane, benzene, and bromodichloromethane exceeded their respective NR 140 Wisconsin Administrative Code enforcement standards (ES) in a sample from well 01-AA-MW-3. Bromodichloromethane also exceeded the ES in a sample from well 01-AA-MW-4. The constituents 1,1,2-trichloroethane, 1,2,4-trimethylbenzene, 1,2-dichloropropane, benzene, bromodichloromethane, and naphthalene exceeded their respective NR 140 Wis. Adm. Code preventive action limits (PAL) in samples from one or more monitoring well.

Field Parameters

Real-time data on temperature, pH, specific conductance, dissolved oxygen, oxidation-reduction potential (ORP), and turbidity were collected from eight of the nine of the wells to complement the analytical data.

These data were used to construct a “geochemical model” of conditions at the site to assist in the interpretation and understanding of attenuation and or transformation processes that may be occurring, and the potential fate of the constituents of interest. Temperature, pH, specific conductance, turbidity, dissolved oxygen, and redox potential were obtained using an In-Situ®, Inc. AquaTROLL 600 multi-parameter water quality monitoring system. Simultaneous temperature, pH, specific conductance, turbidity, dissolved oxygen, and redox readings were taken continuously during pumping until readings stabilized. Water quality field parameter data are presented in Table 6 and the low-flow stabilization logs in Appendix D.

The field parameter data are relatively consistent in each of the eight wells. The field data indicate near-neutral pH conditions in groundwater from wells MW-6, MW-7, and MW-9 while slightly lower pH readings were noted in groundwater from the other five wells. Specific conductivity is an indirect measure of the amount of dissolved solids in groundwater and is used as an indicator of water impacts. Specific conductivity measurements measured at the site were similar between wells and the range of values measured does not indicate significant impacts in groundwater. Turbidity levels were exceptionally low in samples from each well which is advantageous for obtaining accurate water quality analytical results by minimizing false positives and matrix interference effects.

Dissolved oxygen (DO) and oxidation-reduction (ORP) values in groundwater samples were lower than expected given the shallow depth to water, although the presence of lower permeability silt and clay materials above the water table in some areas may limit infiltration that could otherwise bring oxygenated water into the aquifer. The low DO and ORP values, apart from well MW-9, indicate reducing conditions within the aquifer that could be advantageous for the dechlorination of chlorinated hydrocarbons but would inhibit oxidation and natural attenuation of petroleum hydrocarbons. Little is currently known about the potential for natural attenuation of PFAS in the environment.

Building Materials Assessment Six buildings associates with this Truax Field Air National Guard project are slated for demolition or renovation. Building material samples were collected from five of the six buildings to assess the presence of asbestos-containing materials (ACM) and lead-bearing paint (LBP). The Munitions and Inspection Facility (XGFG182017) was not assessed for asbestos and lead paint at the direction of Lt. Col. Meghan Plendl. The results of this sampling and analysis were submitted in separate reports.

Vapor Assessment Vapor intrusion is the migration of volatile constituents from contaminated subsurface soil or groundwater into indoor air spaces of overlying buildings or underground routes such as buried utility lines and trenches. Most vapor intrusion occurs when gases or contaminants in the underlying soil, or contaminants at the water table, enter the unsaturated zone above the water table and migrate to the atmosphere, or into the air space of overlying structures or utility trenches. Less frequently, vapors can enter buildings with groundwater seepage into sumps or flooded basements where contaminants partition directly from the groundwater into indoor air.

No subsurface vapor sampling was proposed or performed during this assessment because existing data do not indicate the presence of hydrocarbons in soil or groundwater at concentrations of concern.

However, a qualitative vapor assessment was performed to evaluate the potential for volatile constituents to migrate into buildings and utilities, or along utility trenches across or away from the site after hydrocarbons were detected in soil and groundwater at the site. Based on the results of this assessment, Ayres Associates concludes that residual hydrocarbon contamination in soil and groundwater is not of sufficient concentration to be a concern from vapor migration or intrusion in existing or future utilities and buildings. Also, the low organic content of the natural soils at the site will not likely promote the generation and migration of methane or other gases through the decomposition of organic matter.

Summary of Findings

Geology and Hydrogeology

Subsurface information collected during this assessment indicates the unconsolidated sediments at the site consist of natural fill materials and stratified layers of ground moraine and lake plain deposits to the depth of exploration at 15 feet. The unconsolidated sediments are presented as two hydrostratigraphic units based on similar hydrologic characteristics such as grain size and permeability. The top unit consists of finer-grained silty sand, clayey sand, silt, and low plasticity clay deposits of low to medium permeability.

The lower hydrostratigraphic unit consists of fine to coarse-grained, poorly graded sand and gravel materials of medium to high permeability. Bedrock was not encountered during this assessment. Depth to bedrock in the site area is estimated to be over 300 below ground surface.

Water level data collected on October 8th indicate that depth to water ranged from 5.16 feet below the top of well casing in well 01-AA-MW-3 to 8.38 feet in well 04-AA-MW-9. The water table was found at or slightly above the interface of the two hydrostratigraphic units (i.e., clay/sand unit interface).

Groundwater flow in the shallow unconsolidated deposits was generally northwest across the site during the October 2020 sampling event at an average horizontal hydraulic gradient of 0.001. The average horizontal groundwater flow velocity in the unconsolidated water table aquifer across the subject site is approximately 0.39 feet/day or 142 feet/year.

Soil Assessment

Per-and Polyfluorinated Alkyl Substances (PFAS)

Per-and Polyfluorinated Alkyl Substances (PFAS) were detected in 29 of the 34 soil samples submitted for PFAS analysis. Trace concentrations of perfluorooctanesulfonic acid (PFOS) were detected in 28 of the soil samples analyzed. Trace concentrations of perfluorooctanoic acid (PFOA) were detected in 7 of the soil samples analyzed. The parameters PFOS and PFOA are the only two PFAS constituents that have established regulatory standards for soil in Wisconsin. Neither of these constituents exceeded their respective regulatory standards in soil samples analyzed during this assessment.

Volatile Organic Compound Analysis (VOCs)

Each of the 34 soil samples collected was analyzed for volatile organic compounds (VOC). All soil samples were collected from above the water table. Results of lab analysis show none of the soil samples analyzed had detectable levels of VOC.

Groundwater Assessment

Per-and Polyfluorinated Alkyl Substances (PFAS)

Detectable concentrations PFAS compounds were found in each of the nine groundwater samples analyzed. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations exceeded the NR 140 Wisconsin Administrative Code enforcement standard of 0.02 μg/L, as well as the USEPA Health Advisory of 0.07 μg/L in samples collected from 6 wells and 9 wells, respectively. The parameters PFOS and PFOA are the only two PFAS constituents that have established groundwater regulatory standards in Wisconsin.

Volatile Organic Compound Analysis (VOCs)

Groundwater samples collected from each of the nine temporary monitoring wells were analyzed for volatile organic compounds (VOC). Laboratory results indicate detectable concentrations of VOC constituents in samples collected from four of the nine monitoring wells. Most of the petroleum and chlorinated hydrocarbon (VOC) constituents detected were found in samples collected from wells 01-AA- MW-2, 01-AA-MW-3, and 01-AA-MW-4 where olfactory observations during well development indicated the likely presence of hydrocarbons. Concentrations of 1,2-dichloroethane, benzene, and bromodichloromethane exceeded their respective NR 140 Wisconsin Administrative Code enforcement standards (ES) in a sample from well 01-AA-MW-3. Bromodichloromethane also exceeded the ES in a sample from well 01-AA-MW-4. The constituents 1,1,2-trichloroethane, 1,2,4-trimethylbenzene, 1,2-dichloropropane, benzene, bromodichloromethane, and naphthalene exceeded their respective NR 140 Wis. Adm. Code preventive action limits (PAL) in samples from one or more monitoring well.

Vapor Assessment

A qualitative vapor assessment was performed during this assessment. Ayres Associates concludes that residual hydrocarbon contamination in soil and groundwater is not of sufficient concentration to be a concern from vapor migration or intrusion in existing or future utilities and buildings. Also, the low organic content of the natural soils at the site will not promote the generation and migration of methane or other gases through the decomposition of organic matter.

Recommendations The following recommendations are provided based on information collected during the Site Characterization Assessment:

Submit this Site Characterization Report to the Wisconsin Department of Natural Resources along with the appropriate review fees in accordance with Wis. Stats. 292.

Prepare a Materials Management Plan (MMP) to address soil and groundwater impacts in the subsurface that are consistent with site redevelopment. The remediation/materials management options selected will be contingent on the specific redevelopment plans.

References

Amec Foster Wheeler, “Draft Report, FY 16 Phase 1 Regional Site Inspections for Perfluorinated Compounds” (March 2018)

Ayres Associates, “Site Characterization Report, XGFG189002-F35: 3-Bay Specialized Hangar, W50SF20F001, Truax Field, Madison, Wisconsin (July 2020)

BB&E Inc., “Final Perfluorinated Compounds Preliminary Assessment Site Visit Report” (December 2015)

Bouwer, H. and R.C. Rice, A Slug Test for Determining Hydraulic Conductivity of Unconfined Aquifers with Completely or Partially Penetrating Wells, Water Resources Research, Vol.12, No.3, 1976, pp.423-

Clayton, Lee and Attig, J.W. 1997. “Pleistocene Geologic Map of Dane County, Wisconsin, WGNHS Bulletin 95, Plate 1.

TOP OF

WELL ID PVC CASING DEPTH TO GW DEPTH TO GW

ELEVATION WATER (ft) ELEVATION WATER (ft) ELEVATION

01-AA-MW-1 858.16 6.50 851.66 7.08 851.08

01-AA-MW-2 857.79 6.48 851.31 6.51 851.28

01-AA-MW-3 856.45 5.12 851.33 5.16 851.29

01-AA-MW-4 857.18 6.01 851.17 6.05 851.13

02-AA-MW-5 858.65 6.70 851.95 6.75 851.90

03-AA-MW-6 858.52 6.80 851.72 6.91 851.61

03-AA-MW-7 858.45 6.75 851.70 6.79 851.66

03-AA-MW-8 859.48 7.20 852.28 7.65 851.83

04-AA-MW-9 860.35 8.30 852.05 8.38 851.97

Note:

1. All well locations surveyed to State Plane Grid coordiantes.

2. Top of PVC elevations surveyed to North American Vertical Datum of 1988 (NAVD88).

10/7/2020 10/8/2020

Table 1 Groundwater Elevation Data

F35 Bed Down Project - Truax Field Madison, Wisconsin

Table 6

Temperature (0F) pH Specific

Conductance ( S /cm)

Dissolved Oxygen (mg/L)

ORP

(mV)

Turbidity

(NTU)

01-AA-MW-1 61.9 6.68 839.6 0.19 -251.9 0.77

01-AA-MW-2 59.3 6.67 754.9 1.09 -132.2 0.00

01-AA-MW-3 --- --- --- --- --- ---

01-AA-MW-4 61.7 6.89 1032.4 0.17 -160.0 0.68

02-AA-MW-5 66.4 6.77 932.4 0.16 -79.1 0.00

03-AA-MW-6 64.1 7.06 807.4 0.36 -178.5 1.89

03-AA-MW-7 67.7 6.93 644.4 0.36 -201.5 0.58

03-AA-MW-8 67.3 6.64 1084.2 0.44 -207.2 0.00

04-AA-MW-9 59.7 7.10 727.9 2.57 -9.8 0.00

--- Measurement not obtained

Water Quality Field Parameter Data F35 Bed Down Project - Truax Field

Madison, Wisconsin

Well ID October 8, 2020

Appendix A

Geological Logs and Monitoring Well Construction and Development Forms

State of Wiscosnin SOIL BORING LOG INFORMATION Department of Natural Resources Form 4400-122 7-98

Route to:

Watershed/Wastewater Waste Management Remediation/Redevelopment Other

Facility/Project Name License/Permit/Monitoring Number Boring Number Wisconsin Air National Guard Air Fighter Wing Facility F-35 Bed Down 02-AA-MW-5 Boring Drilled By: Name of crew chief (first,last) and Firm Date Drilling Started Date Drilling Completed Drilling Method First Name: Last Name:

Firm: Horizon Construction and Exploration 10/7/2020 M/D/Y 10/7/2020 M/D/Y Direct Push WI Unique Well No. DNR Well Id No. Well Name Final Static Water Level Surface Elevation Borehole Dia.

__ __ __ __ __ __ 02-AA-MW-5 Temp Well 6.75 ft. bgs 858.06 2'' Local Grid Origin (estimated: ) or Boring Location Lat. Local Grid Location (If applicable) State Plane ____________N, _____________E ----------- N E

43.132540, -89.334813 Long. ______ Feet S ______Feet W Facility Id. County County Code Civil Town/City/or Village

Dane 13 Madison

SAMPLE SOIL PROPERTIES

SOIL/ROCK DESCRIPTION

AND GEOLOGIC ORIGIN FOR

EACH MAJOR UNIT

-1 SAND, silty, dry, fine to medium grained, SM D

3/5 - no odor, dark brown 0 Sample -2 @

- 1'-1.5' -3 CLAY with sand, dry, low plasticity, CL 0

- fine to medium grained, no odor, dark brown Sample -4 @

- 2'-2.5' -5 0 W

- SAND, wet, fine to medium grained, SP -6 poorly graded, no odor, tan -7

5/5 -8 -9 -10 EOB @ 10 feet -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -24 -25

I hereby certify that the information on this form is true and correct to the best of my knowledge.

Signature Firm

AYRES ASSOCIATES

This form is authorized by Chapters 281, 283, 289, 291, 292, 293, 295, and 299, Wis.Stats. Completion of this report is mandatory. Failure to file this form may result in forfeiture of between $10 and $25,000, or imprisonment for up to one year, depending on the program and conductu involved.

Personally indentifiable information on this form is not intended to be used for any other purpose. NOTE: See instructions for more information, including where the completed form should be sent.

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Appendix D

Low Flow Sampling Stabilization Logs

Low-Flow Test Report:

Test Date / Time: 10/8/2020 9:50:55 AM Project: 02-AA-MW-5 Operator Name: Jeff Steiner

Location Name: 02-AA-MW-5 Well Diameter: 1 in Casing Type: PVC Screen Length: 5 ft Top of Screen: 5 ft Total Depth: 10 ft Initial Depth to Water: 6.75 ft

Pump Type: Peristaltic Tubing Type: HDPE Pump Intake From TOC: 2 ft Estimated Total Volume Pumped:

2100 ml Flow Cell Volume: 130 ml Final Flow Rate: 100 ml/min Final Draw Down: 0 ft

Instrument Used: Aqua TROLL 600 Serial Number: 747002

Test Notes:

Low-Flow Readings:

Date Time Elapsed Time pH Temperature Specific

Conductivity

RDO

Concentration Turbidity ORP

Depth To Water

Flow

+/- 0.2 +/- 5 +/- 30 % +/- 0.3 +/- 20 +/- 20 +/- 0.5

10/8/2020

9:50 AM

00:00 6.82 pH 65.23 °F 953.64 μS/cm 0.68 mg/L 30.11 NTU -30.2 mV 6.75 ft 100.00 ml/min

10/8/2020

9:53 AM

03:00 6.80 pH 65.59 °F 953.94 μS/cm 0.44 mg/L 12.53 NTU -44.5 mV 6.75 ft 100.00 ml/min

10/8/2020

9:56 AM

06:00 6.79 pH 65.87 °F 947.44 μS/cm 0.35 mg/L 3.11 NTU -64.0 mV 6.75 ft 100.00 ml/min

10/8/2020

9:59 AM

09:00 6.78 pH 65.88 °F 946.17 μS/cm 0.29 mg/L 0.01 NTU -72.2 mV 6.75 ft 100.00 ml/min

10/8/2020

10:02 AM

12:00 6.78 pH 66.15 °F 944.90 μS/cm 0.24 mg/L 0.00 NTU -71.4 mV 6.75 ft 100.00 ml/min

10/8/2020

10:05 AM

15:00 6.78 pH 66.41 °F 938.44 μS/cm 0.18 mg/L 0.00 NTU -80.6 mV 6.75 ft 100.00 ml/min

10/8/2020

10:08 AM

18:00 6.78 pH 66.52 °F 937.48 μS/cm 0.16 mg/L 0.00 NTU -83.5 mV 6.75 ft 100.00 ml/min

10/8/2020

10:11 AM

21:00 6.77 pH 66.45 °F 932.36 μS/cm 0.16 mg/L 0.00 NTU -79.1 mV 6.75 ft 100.00 ml/min

Samples