FINAL_SI-Report_BIA-Fmr-Kotz-Hospital-School_May-2023.pdf

SITE INVESTIGATION REPORT

KOTZEBUE FORMER IHS/BIA HOSPITAL-SCHOOL

PIPELINE RELEASE

PREPARED FOR:

BUREAU OF INDIAN AFFAIRS

ALASKA REGIONAL OFFICE

3601 C STREET, SUITE 1100

ANCHORAGE, AK 99503

MAY 2023

CONTRACT 140A1321P0004

PREPARED BY:

4300 B STREET, SUITE 605

ANCHORAGE, AK 99503

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Site Investigation Report – Former IHS/BIA Hospital-School Pipeline Release Kotzebue, Alaska Page i

TABLE OF CONTENTS

ACRONYMS AND ABBREVIATIONS .......................................................................................... III EXECUTIVE SUMMARY ............................................................................................................. V

1 INTRODUCTION

1.1 Project Objectives

1.2 Background Information

1.2.1 Previous Investigations

1.3 Site Description

1.3.1 Climate

1.3.2 Geology and Hydrogeology

2 REGULATORY CRITERIA

3 FIELD ACTIVITIES

3.1 Permit Applications

3.2 Site Inspection

3.3 Groundwater Monitoring Well Installations

3.4 Well Development, Purging, and Groundwater Sampling

3.5 Soil Borings and Sampling

3.6 Work Plan Deviations

3.7 Decontamination

3.8 Waste Management

4 INVESTIGATION RESULTS

4.1 Soil Sampling Results

4.1.1 Geology

4.1.2 Field Screening

4.1.3 Soil Analytical Results

4.2 Groundwater Investigation Results

4.2.1 Groundwater Quality Field Parameters

4.2.2 Groundwater Analytical Results

5 DATA QUALITY ASSURANCE AND QUALITY CONTROL

6 RESULTS AND DISCUSSION

6.1 Potential Receptors and Pathways

6.1.1 Kotzebue Sound Receptors

6.1.2 VOC Off-Gas Receptors

6.1.3 Worker Exposure

6.1.4 Private/Public Well Water Exposure

6.2 Soil Conceptual Model

6.3 Groundwater Conceptual Model

6.4 Data Gaps and Uncertainties

7 RECOMMENDATIONS AND NEXT STEPS

8 REFERENCES

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TABLES

Table 1. Kotzebue Climate Summary Table 2. Project Screening Levels Table 3. Soil Boring, Monitoring Well, and Sample Summary Table 4. Soil Boring PID Readings Table 5. Summary of Soil Analytical Results ...................................................... Attachment Tables Table 6. Summary of Groundwater Analytical Results ..................................... Attachment Tables Table 7. Groundwater Field Measurements ..................................................... Attachment Tables

FIGURES

Figure 1 Historical Environmental Investigation Activities Map Figure 2 Monitoring Well Location Map Figure 3 2021-2022 Soil Boring Location Map Figure 4 2021 Soil Exceedances Map Figure 5 July 2022 Groundwater Exceedances Map Figure 6 October 2022 Groundwater Exceedances Map

APPENDICES

Appendix A City of Kotzebue Right-of-Way Permits Appendix B Project Deviation Notices Appendix C IDW Disposal Approvals C-1 Low-Level VOC Soil Cutting Disposal (SB07, SB10, SB12, SB17, and SB18)

C-2 Non-Chlorinated Soil Cutting Disposal (SB05, SB06, SB08. SB09, SB11, SB13, SB14A, SB16, SB19)

C-3 Potential Chlorinated Soil Cutting Disposal Signed (SB04, SB14, SB15) Appendix D Boring Logs Appendix E Well Construction Forms Appendix F Well Purge Records F-1 July 2022 Samples F-2 October 2022 Samples Appendix G Lab Reports G-1 October 2021 Samples (Report 1217121) G-2 July 2022 Samples (Report 1224482) G-3 October 2022 Samples (Report 1226215) Appendix H ADEC Data Quality Review Checklists H-1 Lab Report 1217121 (October 2021 Samples) H-2 Lab Report 1224482 (July 2022 Samples) H-3 Lab Report 1226215 (October 2022 Samples) Appendix I Daily Report I-1 October 2021 Field Event I-2 June and July 2022 Field Events I-3 October 2022 Field Event Appendix J ADEC-KUNA Comment Table J-1 ADEC Comments and Responses Table J-2 Kuna Response Table to ADEC Comment #18

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ACRONYMS AND ABBREVIATIONS

~ approximately > greater than % percent ± plus or minus °C degree(s) Celsius °F degree(s) Fahrenheit µg/L microgram(s) per liter µS/cm microsiemens per centimeter AAC Alaska Administrative Code ADEC Alaska Department of Environmental Conservation AK Alaska AST aboveground storage tank ASTM American Society for Testing and Materials Ave. Avenue Avg. Average bgs below ground surface BIA Bureau of Indian Affairs BTEX Benzene, toluene, ethylbenzene, and xylenes COC Chain-of-Custody CoC chemicals of concern Cumene Isopropylbenzene DRO diesel-range organics EDB 1,2-dibromoethane EDC 1,2-dichloroethane ESA Environmental Site Assessment ft feet GRO gasoline-range organics IDW investigation-derived waste IHS Indian Health Service KEA Kotzebue Electric Association KIC Kikitagruk Inupiat Corporation LOD limit of detection LOQ level of quantitation

Kotzebue, Alaska Page iv m meter MEK 2-Butanone mg/kg milligram(s) per kilogram MIBK 4-Methyl-2-pentanone MS/MSD matrix spike/matrix spike duplicate MW Monitoring Well MW monitoring well No. Number NOAA National Oceanic and Atmospheric Administration NWABSD Northwest Arctic Borough School District ORP oxidation reduction potential PAH polycyclic aromatic hydrocarbon(s) PAL Project Action Limit PCE Tetrachloroethylene PID photoionization detector POL petroleum, oil, and lubricant PRP Potential Responsible Party PSL project screening level PVC polyvinyl chloride QC quality control ROW right-of-way RRO residual-range organics SIM selected ion monitoring SOW Scope of Work St. Street TCE trichloroethene Temp. Temperature UST underground storage tank VOC volatile organic compound

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EXECUTIVE SUMMARY

The purpose of the 2021 and 2022 site investigation at the former Kotzebue IHS/BIA Hospital and School pipeline release site (ADEC Site File No. 410.38.025) was to determine if the previously noted groundwater impacts at the site extend to the north and potentially impact Kotzebue Sound. Additionally, the investigation included further characterization of soil impacts in/around the former pipeline and its branches.

After obtaining appropriate right-of-way (ROW) permits from the City of Kotzebue, Kuna performed 17 soil borings and installed 6 monitoring wells in October 2021. Soil samples were collected from each boring for laboratory analysis of gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs) at depths just above the groundwater. Only one sample, SB04 (4.5-5 ft bgs) exceeded any of the Table B1 or B2 arctic zone cleanup standards (Title 18, Alaska Administrative Code (AAC) Chapter 75); DRO was detected in this sample at a concentration of 18,400 milligrams per kilogram (mg/kg), the cleanup standard is 12,500 mg/kg.

Groundwater from the newly installed monitoring wells (MW11 – MW16) was sampled in July 2022 and October 2022. Some petroleum related compounds were detected in these wells at concentrations exceeding the Table C thresholds from 18 AAC 75, including naphthalene, 1- and 2-methylnaphthalene, and 1,2,4-trimethylbenzene. Widespread petroleum related detections and exceedances were not noted. The groundwater concentrations at the northeast side of the site, near the intersection of Bison St. and Front St. (aka, Shore Ave.) may be related to a non-pipeline release or spill. Similarly, the noted groundwater impacts around MW16 (east side of Turf St.) may also be attributed to a separate spill or release.

The 2020 groundwater sampling (MW5, MW6, MW9, MW10), in conjunction with the 2022 sampling indicates that groundwater concentrations are rapidly attenuated as the groundwater moves to the north. This information, in combination with the limited detections in the Shore Ave. wells indicates that impacts to Kotzebue Sound are not likely occurring.

Recommendations for next steps for the site include the continued monitoring of the site groundwater through the existing monitoring wells on an annual basis and performing additional potential investigations of other sources in the areas of MW11/MW12 (Bison St/Front St) and MW16 (east side of Turf St.). The implementation of formal institutional controls to limit potential exposures should also be initiated to enable the site to potentially receive future closure approval from ADEC. Excavation of soils and the removal of the abandoned pipeline is not recommended due to the potential exposure risks and risks to damaging existing utilities in this area.

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1 INTRODUCTION

This Site Investigation Report describes the field activities and investigation results for the installation and sampling of new groundwater monitoring wells in the area around the former Indian Health Services (IHS) and Bureau of Indian Affairs (BIA) Hospital and School pipeline release in Kotzebue, Alaska. In conjunction with the installation of these wells, soil sampling and characterization was performed in the area around the former pipeline. The site is identified by the Alaska Department of Environmental Conservation (ADEC) Contaminated Sites Program under Site File No. 410.38.025 (Hazard ID No. 25558).

Kuna Engineering, LLC performed this site investigation and prepared this report under Contract 140A1321P0004.

1.1 PROJECT OBJECTIVES

The primary objectives for the site investigative activities are as follows:

• Determine the downgradient and side-gradient migration of fuel-impacted groundwater from the former IHS-BIA site and if the impacted groundwater extends to Kotzebue Sound or other properties.

• Determine the degree and extent of fuel-related soil impacts in the immediate vicinity of the pipeline to assess potential remedial options.

To meet the first objective, six groundwater monitoring wells were installed between the site and Kotzebue Sound: four along Shore Ave. to the north of the site, and one on each side (west and east) of the site. Groundwater from these wells was sampled to determine the presence and concentrations of petroleum hydrocarbons.

To meet the second objective, five soil borings were performed throughout the former property including in the area of the former pipeline. Soils from three of the borings for the monitoring wells were also analyzed to determine the extent and degree of potential impacts from migration of the fuel releases.

1.2 BACKGROUND INFORMATION

The BIA is identified by the ADEC as the Potential Responsible Party (PRP) for the environmental impacts resulting from the various fuel releases, spills, and leaks from the former pipeline that provided heating fuel to the BIA-IHS facilities located on the northwest side of the City of Kotzebue, AK, including the former school and hospital. Outlines of these former facilities are shown on Figure 1.

The impacted property/site is listed on ADEC’s Division of Spill Prevention and Response website (Hazard ID 25558). It was formally known as the former IHS/BIA Hospital and school grounds, Tract 4A and Lots 3, 4 and 5, between Shore Avenue and 3rd Avenue (north-south) and between

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Turf Street and Bison Street (east-west). The site is currently occupied by facilities/buildings operated by Maniilaq Association, Kikitagruk Inupiat Corporation (KIC), and the Northwest Arctic Borough School District (NWABSD).

The former pipeline provided #1 diesel fuel (arctic heating oil) to the school and the former hospital from a tank farm northeast of the property; the pipeline became damaged at an unknown time and leaked an unknown quantity of fuel prior to its discovery in 1980 after ADEC was notified that fuel was found seeping into the elementary school’s basement. It is estimated that 100,000 to 200,000 gallons of fuel may have leaked from the fuel line over time. Currently, the former pipeline is abandoned in place.

Numerous environmental investigations and remedial actions have occurred at the site since the original discovery of the fuel in the ground. The following subsections provide a description of some of the more extensive and recent efforts that provide the general basis for this project.

1.2.1 Previous Investigations

In 2013, WHPacific Inc. (WHPacific) was contracted by Maniilaq to conduct a Phase I Environmental Site Assessment (ESA) of Lots 3 and 4 individually. These site assessments were completed in May of 2014 and included a records review of environmentally and historically relevant information. A site reconnaissance visit of the area occurred between March 26-28, 2014 and a lead-based paint survey was performed by ChemTrack Alaska Inc.

(ChemTrack) on March 27. The purpose behind these assessments was to update the 2009 ESA performed by Shannon and Wilson to evaluate the environmental conditions of the Subject Properties prior to a property and building transfer from the IHS to Maniilaq. In general, these assessments were performed according to the American Society for Testing and Materials (ASTM) Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process, Designation E1527-13 (ASTM E1527-13).

Following the Phase 1 ESA of the Subject Properties (Lots 3 and 4), an evaluation report concluded that the groundwater was impacted by hydrocarbon-based products from several different sources. The northeasterly groundwater flow direction likely results in the migration of the soil and groundwater impacts through the fluctuating groundwater levels and highly variable smear zone of saturated soils at the site. As a result, the overall affected soil area is likely larger than the original spill/leak site(s) (WHPacific 2015).

No drinking water or non-potable water wells exist on either Lots 3 and 4. Water and sewer services for the structures on these lots is provided through outside sources, primarily the City of Kotzebue. All current utilities on Lot 3 are buried within one conduit and there was little or no proof of previously existing utilities from historical records, but any future investigations are advised to proceed with caution.

Lot 4 contains four aboveground storage tanks (ASTs) along the northern perimeter but only two were active in 2014. All piping for the four ASTs is above ground. It is quoted in the 2014

Kotzebue, Alaska Page 3 evaluation that no other activities currently impacting the environmental degradation or risking exposure to human health, although the extent of environmental impacts required further investigation.

During 2014 and 2015, WHPacific, Inc. completed a site investigation on the properties located within Lots 3, 4, and 5 and Tract 4A, otherwise referred to as the Subject Property, further referred to as the “site.” At the time of the investigation, the site was leased by several different organizations including KIC, BIA, IHS, Maniilaq, the City of Kotzebue, and the NWABSD. Included in the report is a brief background of the site’s environmental concerns and a discussion about the field activities performed in 2014 and 2015, along with the analytical results, a conclusion and recommendations based on the data found.

Several activities were included in the 2014 and 2015 field events. Soil and groundwater sampling occurred in 2014 to determine the environmental hazards present throughout the site.

Groundwater sampling and groundwater elevations were measured through the 2015 field activities to understand the trends in impacted groundwater concentrations and migration. Soil gas sampling also occurred in 2015 to identify and evaluate the potential risks from soil vapors within Tract 4A where the school playground is currently located. The 2014-2015 Site Investigation provides the most recent comprehensive data for the site.

Other activities performed through the 2014-2015 investigation included the digging of four test pits, performing 45 soil borings, and installing 10 groundwater monitoring wells. The soil borings were implemented in areas known to be in the proximity of the former pipeline.

For the 2015 investigation, the Project Action Limit (PAL) for the impacted soil at the site was defined from Table B1, Method Two, Arctic Zones, and the PAL for the groundwater was defined from Table C in the 18 Alaska Administrative Code (AAC) 75 Oil and Other Hazardous Substances Pollution Control. The locations that exceeded the PAL for soil and groundwater samples were along the BIA pipeline corridor on Tract 4A and northwest of the Ferguson Building in the right-of-way (ROW).

The 2015 investigation report recommendations consist of removal and proper treatment of the soils above PAL and removal of the former pipeline and the surrounding soil. The soil gas survey indicates some areas of potential exposure risks from airborne hydrocarbon fumes.

Other potential sources of contamination were found to be present aside from the BIA pipeline including former ASTs and underground storage tanks (USTs), and likely historical surface spills.

Proper removal and remediation are recommended for any surface spills and out of service USTs and ASTs in order to prevent future soil and groundwater contamination.

More information is included in the investigation report such as photographs, field notes, photoionization detector (PID) readings, 2014 well diagrams/installation forms, groundwater monitoring forms, and the full analytical data reports.

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The Tanana Commercial Company - Environmental Management Joint Venture completed recent site activities in two phases, including additional site characterizations, a limited removal action, and continued groundwater monitoring. The first phase, completed in July of 2020, included site characterization sampling. The second phase, performed in September and October 2020, included a limited soil removal and site-wide groundwater monitoring.

Site sampling/characterization was intended to delineate the extent of impacts on the IHS owned parcels and to determine potential human health risks from soils that may exceed appropriate ADEC cleanup levels. The limited soil removal provided for the removal of impacted soils that exceed cleanup levels on the north side of the FRF Building, in Lot 4. Groundwater monitoring activities were conducted on September 30 and October 3-4 at each of the 10 monitoring wells on the site.

Results from the 2020 site activities indicate that the groundwater is impacted throughout the site, with MW5, MW9, and MW10 having the highest petroleum related compound concentrations, and with free product encountered in wells MW1 and MW6. Continued groundwater monitoring is recommended to assess migration and attenuation trends.

Tetrachloroethylene (PCE) was encountered in several of the wells; the source of this previously undetected compound is not known. Soil sampling results identified an area of diesel-range organics (DRO) impacted soil above the ADEC’s migration to groundwater cleanup levels to the north of Buildings 307, 312, and 316. A second area of impacted groundwater was also identified around the FRF Building. Both areas are within Lots 3 and 4.

At least two rounds of soil vapor sampling have been performed in the school buildings over the past several years, including sampling in January 2018 (Shannon and Wilson, 2018) and in October 2020 (Rescon, 2021). In the more recent sampling, some detections of fuel related compounds were noted; with only one indoor air location (IA-04) registering detections above the appropriate action level. Some sub-slab (below the concrete slab of the building) air was also found to have fuel related compounds at concentrations above appropriate action levels.

1.3 SITE DESCRIPTION

Kotzebue is in northwest coastal Alaska, located on the Baldwin Peninsula, about 25 miles north of the Arctic Circle in the Northwest Arctic Borough. The approximate coordinates are 66° 53’ N and 162° 36’ W. Kotzebue is located on a narrow spit between a lagoon and the Kotzebue Sound.

The former BIA Hospital and School, where the pipeline is terminated at, sits on Lot 5 and Tract 4A. The site around the former pipeline is relatively flat, consistent with a natural coastal tidal flat, with intermittent permafrost near the surface. The groundwater generally flows northeast toward the Kotzebue Sound. Lots 3, 4, and 5 and Tract 4A are all developed properties, with several structures and a gravel surface.

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Lot 3 is currently a developed gravel lot owned by the IHS. Present on this lot is a parking lot for the Ferguson Building, several Maniilaq structures, and an AST. The structures consist of four duplex units and a multiunit apartment complex. All five structures belong to Maniilaq and used to house employees. These structures include cement walled basements with utilities running through from underneath the sidewalk. The AST supplies fuel to three boilers that produce heat for all five structures. Electric and cable/telephone utilities run overhead for the structures.

Lot 4 is a developed gravel pad also owned by the IHS. This lot contains the Ferguson Building, a parking lot, driving lanes, and an AST. The Ferguson Building is owned by Maniilaq and contains offices for Maniilaq’s employees and health services for the community. The parking lot and driving lanes are mainly used by the Ferguson Building tenants. The AST supplies fuel to the facility’s backup power generators, located in a shed adjacent to the tank.

Lot 5 belongs to KIC; this property was transferred to KIC in 1997 from the IHS. It contains a large, fenced industrial area with a building (No. 314) historically associated with the former hospital.

This building stores various petroleum products, chemicals and equipment. The fenced area is also used by KIC and Maniilaq as storage for vehicles, equipment, Conex boxes, fuel tanks, a stockpile of soil berms, and a telecom utility easement. The fuel tanks were formerly used to fuel the former hospital but are now marked “out of service.” Outside of the fenced area is a portion of a parking lot on the east corner of the overall lot, and on the west end are driving lanes outside of the Ferguson Building.

Tract 4A is the largest parcel (11.52 acres) in this area and is owned by the NWAB. This lot encompasses the school grounds with the elementary, middle, and high school buildings, two playgrounds, the NWABSD office building, a maintenance area for school vehicles and equipment, and a few other school district buildings. An access road and a utility right-of-way runs through the northwest side of the lot as well as a portion of the fuel pipeline that is potentially identified as the primary former leak location. On the southwest side of the lot, several portions of the pipeline exist with junctions and branch lines servicing the school buildings and the former hospital’s fuel tanks.

1.3.1 Climate

Kotzebue lies within the dry, subarctic, transitional climate of Alaska and is generally characterized by long, snowy and very cold winters, and short, mild summers. Daily temperature variations are low to minimal throughout the year with an annual normal of 11.6 degrees Fahrenheit (°F) and a minimum normal of 8.0°F in October, with frequent winds, low humidity and limited cloud cover. From 1991 to 2020, average temperatures (January through July) ranged from -0.7 to 56.6°F, with an annual mean temperature of 25.3°F. Temperature extremes recorded from 1930 to 2013 ranged from -58°F to 85°F. Annual precipitation from 1991 to 2020 averaged

11.36 inches per year, although precipitation may vary considerably according to local topography. The wettest months are July and August, which receive an average of 1.6 to 2.13

Kotzebue, Alaska Page 6 inches of rain, whereas the driest months of March, April, and May receive less than 1 inch of rain per month on average (National Oceanic and Atmospheric Administration [NOAA] 2020).

Table 1 provides a summary of annual climate data.

Table 1. Kotzebue Climate Summary

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Total

Climate Data Kotzebue Airport, Alaska from 1991 to 2020 (NOAA, May 2020) Avg. Max. Temp.

(°F) 5.8 9.9 10.4 25.1 40.3 54.5 61.4 57.8 48.8 32.1 17.2 9.9 31.1

Avg. Min. Temp. (°F) -7.2 -4.5 -4.8 10.0 28.5 43.0 51.8 48.9 39.9 24.1 6.9 -2.7 19.5 Avg. Precipitation.

(in.) 0.62 0.85 0.52 0.56 0.44 0.60 1.60 2.13 1.42 1.07 0.82 0.73 11.36

Avg. Snowfall (in.) 9.4 13.1 6.4 4.7 1.2 0 0 0 0.6 5.9 11.0 11.9 64.2 Notes: See Acronyms and Abbreviations for definitions.

1.3.2 Geology and Hydrogeology

The former BIA Hospital/School pipeline, abandoned in place, is located along the School Utility Road and the school playground south of the Kotzebue Sound. According to Dorava and Brekken (1995), the bedrock on the Baldwin Peninsula is deep and is covered by surficial materials ranging from 150 meters (m) to 750 m thick. This surficial material contains a sequence of marine and glacial deposits visible as sea cliffs. The organic rich soils near Kotzebue, where permafrost is present, have a maximum layer of approximately 1-5 m depth. Soils are alternately wet and dry, typically dark-gray and mottled, due to variations in temperatures and precipitation. The prime silt loam soils are settled on deep silty alluvium. According to Dorava and Brekken (1995), the continuous permafrost influences the groundwater recharge and flow and acts as an impermeable layer to underlying geologies. In the areas where permafrost is absent, the groundwater is hydraulically connected to the Kotzebue Sound and susceptible to saltwater intrusion. The groundwater discharges into the sound to the west, as well as the lagoon to the east and wetlands throughout the area. The groundwater is typically at sea level below the ground surface. The groundwater contains chloride at depths of 25 m and 80 m deep.

Groundwater in the areas adjacent to or near the Kotzebue Sound are tidally influenced; the tide fluctuates roughly 1 foot at most (NOAA 2022). Although the tidal fluctuations are fairly low, Kotzebue Sound is heavily influenced by storm surges, winter ice buildup, and spring ice melts.

These fluctuations historically caused flooding that likely also impacted groundwater levels. The installation of the sea wall on the north side of Shore Ave. has decreased the flood risks and reduced the groundwater interactions south of the sea wall. The low specific conductivity as measured in the wells (values in the hundreds of microsiemens per centimeter µS/cm versus Kotzebue Sound measurement of ~7,000 µS/cm in July 2022) is one indication of this isolation.

Note that it is likely that some groundwater-Sound interactions still may occur, especially when sea levels rise enabling the seawater to potentially travel under the sea wall.

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2 REGULATORY CRITERIA

This project included the collection of soil and groundwater samples. The primary chemicals of concern (CoC) are typical petroleum related compounds likely attributed to the pipeline fuel releases; these include:

• Gasoline range organics (GRO)

• Diesel range organics (DRO)

• Polynuclear aromatic hydrocarbons (PAH)

• Residual range organics (RRO)

• Benzene, toluene, ethylbenzene, and xylenes (BTEX) and other volatile organic compounds (VOCs)

Previous investigations have also detected non-petroleum related VOCs, including trichloroethene, chloroform, and tetrachloroethylene (aka, perchloroethylene, PCE) in both soils and groundwater.

The applicable project screening levels, based on Alaska cleanup standards are identified in Table 2.

Table 2. Project Screening Levels

Analyte Soil Project Screening Level (mg/kg) 1

Groundwater Project Screening Level (µg/L) 2

Fuels and BTEX

GRO 2200 2,200

DRO 1500 1,500

RRO 1100 1,100

Benzene 16 4.6

Toluene 8000 1,100

Ethylbenzene 72 15

Xylenes (total) 190 190

PAHs

1-Methylnaphthalene 310 11

2-Methylnaphthalene 420 36

Acenaphthene 6300 530

Acenaphthylene 3100 260

Anthracene 31000 43

Benz[a]anthracene 20 0.3

Benzo[a]pyrene 2 0.25

Benzo[b]fluoranthene 20 2.5

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Table 2. Project Screening Levels

Analyte Soil Project Screening Level (mg/kg) 1

Groundwater Project Screening Level (µg/L) 2

Benzo[g,h,i]perylene 3100 0.26

Benzo[k]fluoranthene 200 0.8

Chrysene 2000 2

Dibenzo[a,h]anthracene 2 0.25

Fluoranthene 4200 260

Fluorene 4200 290

Indeno[1,2,3-cd]pyrene 20 0.19

Naphthalene 42 1.7

Phenanthrene 3100 170

Pyrene 3100 120

VOCs

2-Butanone (MEK) 53000 5,600

Bromobenzene 410 62

Bromodichloromethane 5.3 1.3

Bromoform 340 33

Bromomethane 15 7.5 n-Butylbenzene 6800 1,000 sec-Butylbenzene 14000 2,000 tert-Butylbenzene 14000 690

Carbon disulfide 1600 810

Carbon tetrachloride 13 4.6

Chlorobenzene 370 78

Chloroform 5.8 2.2

Chloromethane 250 190

1,2-Dibromoethane (EDB) 0.62 0.075

Dibromochloromethane 140 8.7

Dibromomethane 45 8.3

1,2-Dichlorobenzene 2300 300

1,3-Dichlorobenzene 2000 300

1,4-Dichlorobenzene 31 4.8

Dichlorodifluoromethane 220 200

1,1-Dichloroethane 67 28

1,2-Dichloroethane (EDC) 8 1.7

1,2-Dichloropropane 25 8.2 cis-1,3-Dichloropropene 30 4.7

Hexachlorobutadiene 14 1.4

2-Hexanone 380 38

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Table 2. Project Screening Levels

Analyte Soil Project Screening Level (mg/kg) 1

Groundwater Project Screening Level (µg/L) 2

Isopropylbenzene (Cumene) 2500 450

4-Methyl-2-pentanone (MIBK) 69000 6,300

Methylene chloride 630 110

Methyl-t-butyl ether 970 140

Naphthalene 42 1.7

Styrene 8100 1,200

1,1,1,2-Tetrachloroethane 30 5.7

1,1,2,2-Tetrachloroethane 8.8 0.76

1,2,3-Trichlorobenzene 110 7

1,2,4-Trichlorobenzene 66 4

1,1,1-Trichloroethane 160000 8,000

1,1,2-Trichloroethane 2.3 0.41

Trichlorofluoromethane 41000 5,200

1,2,3-Trichloropropane 0.089 0.0075

1,2,4-Trimethylbenzene 400 56

1,3,5-Trimethylbenzene 360 60

Trichloroethylene 7.1 2.8

Vinyl acetate 2100 410

Vinyl chloride 0.69 0.19 Notes: See Acronyms and Abbreviations for definitions.

1 Unless otherwise noted, soil PSLs are the cleanup levels as listed in 18 AAC 75.341, Tables B1 and B2 for arctic zone soils (ADEC 2021).

2 Unless otherwise noted, groundwater PSLs are the cleanup levels as listed in 18 AAC 75.345, Table C.

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3 FIELD ACTIVITIES

Project activities were performed according to the procedures and methods outlined in the ADEC-approved Work Plan (Kuna 2021). The field activities included the performance of soil borings for both the collection of soil samples and the subsequent installation of groundwater monitoring wells. Well development and sampling were performed through several site visits. A timeline for the completed field activities is as follows:

• October 2021 – Mobilized to Kotzebue and completed 16 soil borings and installed six monitoring wells. Unfortunately, the newly installed wells could not be developed and sampled due to the cold conditions and the field crew demobilized.

• June 2022 – Mobilized to Kotzebue to attempt to develop and sample previously installed monitoring wells; unfortunately, the wells remained frozen, and the field crew demobilized.

• July 2022 – Mobilized to Kotzebue and developed and sampled the monitoring wells.

• October 2022 – Mobilized to Kotzebue and sampled the monitoring wells.

In general, the following provides an overview of the major activities performed through these site visits:

• During the October 2021 site visit, the site was inspected for evidence of recent spills or other releases and any potential impacts. The location of each existing groundwater monitoring well was verified, and the condition of the wells was noted. The former pipeline, existing utilities, and the city ROWs around the wells were pinpointed and marked (with the help of City personnel) to site the exact locations for the groundwater monitoring wells and soil borings. A detailed review of the site was also performed to verify the continued presence or status of any USTs located within Lot 4A. The locations of these tanks are shown on Figure 1; no locations changed from the locations as identified in the work plan (Kuna 2021).

• Soil borings were performed to collect the soil samples for field screening and laboratory analysis at locations along/surrounding the former pipeline to assess the degree and extent of impacted soils around this pipeline. Soil samples were also collected from the borings performed for the installation of each groundwater monitoring well. The specific locations of the soil borings along the former pipeline were determined in the field after identifying any impeding utilities.

• Six groundwater monitoring wells were installed at the locations as specified on Figure 2.

The locations of these wells were field determined based on the ROW limits and any impeding utilities.

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• Groundwater samples were collected from the newly installed groundwater monitoring wells and submitted for laboratory analysis. Field parameters and groundwater elevations were also recorded for each well.

The following sections describe the specific approach and field sampling methods that were used for the activities described above. In general, all field activities and sampling followed applicable ADEC sampling guidance (ADEC 2019) and the methods included in the approved work plan (Kuna 2021). Some variances in the sampling approach or methods occurred in response to field conditions; these variances were documented in the field notes and included in this report.

Significant variances were discussed and approved by ADEC prior to the completion of the sampling. These are described in the following subsections.

3.1 PERMIT APPLICATIONS

Prior to the soil borings and the installation of the monitoring wells, Kuna prepared and submitted a City of Kotzebue ROW application. This application was necessary to permit the installation of the monitoring wells in the Shore Ave. right-of-way and along the edge of Bison Street and Turf Street. Following a meeting of the Planning Department in September 2021, the City of Kotzebue provided the permit; a copy of the ROW permits for each of the monitoring wells is provided in Appendix A.

3.2 SITE INSPECTION

Upon arrival to the site in October 2021, the City of Kotzebue and Kotzebue Electric Association (KEA) assisted in locating existing buried utilities and the City ROW boundaries. Any utilities around the former pipeline were also identified and marked to ensure the safe performance of the soil borings in this area. Locations of the utilities, particularly along/within School Utility Driver are shown on Figure 3.

The locations of the existing groundwater monitoring wells were verified to confirm their status and condition. To the extent possible, groundwater elevations were measured in each well, also noting the presence/depth of any free product or sheens in these wells.

3.3 GROUNDWATER MONITORING WELL INSTALLATIONS

After the ROW and utilities were marked, borings for each well were performed using the Geoprobe 6620DT drilling rig. The cores for each boring were continuously screened using the PID. PID readings provide a general assessment on the degree of petroleum impacts in the soils around the groundwater monitoring wells.

One soil sample from each boring was collected for laboratory analysis. The soils sampled were from the six-inch depth interval just above the water table (i.e., saturated soils as noted through observation of the cores and the depths identified in the nearby groundwater monitoring wells).

The soil samples were collected for the analyses as identified in Table 3.

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Groundwater monitoring wells were installed according to a common design, consisting of a two-inch diameter well completed with a flush-mount finish and installed to a depth of approximately 10 feet (ft) below the ground surface (bgs). Each well was constructed using a polyvinyl chloride (PVC) casing, with a five-foot screened section at the bottom of the well. The screen slot size is a 0.01-in and is surrounded by a sand filter pack, using #20 sand. A locking well cap was installed at the top of the well just below the flush-mount cover.

3.4 WELL DEVELOPMENT, PURGING, AND GROUNDWATER SAMPLING

As noted, the development and sampling of the wells did not occur immediately after the well construction; cold weather and snow prevented this activity from occurring in October 2021. The wells were developed/purged in July 2022 to restore the natural hydraulic conductivity and remove any sediment buildup in the well. The well development also removed stagnant water to ensure the samples are representative of the local groundwater conditions. The development goal was to reach static water quality conditions. All well development water was contained as investigative derived waste (IDW) and subsequent sampling/analysis was performed to guide in proper waste disposal (see subsequent section).

Groundwater sampling at each well was conducted two to three hours before and after low tide to minimize the influence of high tide and higher water level. Samples were collected with a QED 1.75-inch pneumatic bladder pump and dedicated tubing using low-flow methods. Pump intakes were set approximately 1 foot below the depth to water. Field water quality parameters were monitored using a YSI 556 multiparameter meter with a flow-through cell; measurements were recorded until parameters were stable. Water quality parameters were considered stable when at least four parameters (including temperature) had successive stable readings, collected four minutes apart. Drawdown during purging did not exceed 0.3 ft. Field water quality parameters and sampling notes were recorded on groundwater purging and sampling logs (Appendix F).

Prior to the purging of each well for sampling, the water levels were measured. Times were also noted to correlate with known tide levels for the Kotzebue Sound. Water levels and field water quality parameters are summarized in Table 7. Tide levels during the sampling events are also included in the table.

3.5 SOIL BORINGS AND SAMPLING

In addition to the groundwater sampling, soil samples were collected from locations directly adjacent to the former BIA pipeline, as well as one soil sample from the borings performed for each of the six new monitoring well locations (as described above). According to task 3 of the project/contract Scope of Work (SOW) (BIA 2021), the degree and extent of the soil impacts in the immediate vicinity of the pipeline were assessed on Tract 4A and Lot B, with the objective to determine the quantity of impacted soil that may require removal should the pipeline be removed (in the future). Direct push soil borings were used for this assessment. Samples were collected along the pipeline or at every junction or pipeline end, as shown in Figure 3. Each boring

Kotzebue, Alaska Page 14 was performed to depths just below the water table, or approximately five to seven feet bgs.

Cores from each boring were continuously analyzed/screened via PID for petroleum impacts.

Samples from the depth intervals (six inches) from each boring core with the highest PID readings were collected for the laboratory analyses.

A total of 15 soil borings were advanced using a Geoprobe 6620DT direct push drill rig at the former HIS/BIA hospital site. The first three proposed soil boring sites (SB-1, SB-2, SB-3-2021) were not drilled due to concerns about unmarked utility lines; this is further described in the subsequent deviations section of this report. Borings were advanced at or as close as possible to proposed locations and were moved only to accommodate underground utilities or property boundaries. The borings were advanced to make observations, conduct field screening, and collect analytical soil samples. Each boring was documented on a Soil Boring Log (Appendix D), which included a description of soil lithology, moisture/depth to groundwater observations, visual and olfactory observations, associated samples, and PID results. The borings were logged continuously for geological profiling purposes and to identify potentially contaminated intervals using PID field screening.

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Table 3. Soil Boring, Monitoring Well, and Sample Summary

Boring/ Monitoring Well

Identification

Total Boring Depth (ft bgs)

Date Performed

Depth to Groundwater

(ft bgs)

Well Screen Interval (ft bgs)

Samples Collected

SB04-2021 8 10/24/21 6 N/A 1 soil sample (4.5-5 feet) SB05-2021 6 10/24/21 4.5 N/A 1 soil sample (4.5-5 feet) SB06-2021 8 10/23/21 5 N/A 1 soil sample (4.5-5 feet) SB07-2021 10 10/24/21 6 N/A 1 soil sample (5.5-6 feet) SB08-2021 8 10/24/21 7 N/A 1 soil sample (6-7 feet) SB09-2021 10 10/24/21 6.5 N/A 1 soil sample (5.5-6.5 feet) SB10-2021 8 10/24/21 6 N/A 1 soil sample (5.5-6 feet) SB11-2021 10 10/23/21 6.5 N/A 1 soil sample (5.5-6.5 feet) SB12-2021 10 10/24/21 6 N/A 1 soil sample (5.5-6 feet) SB13-2021 9 10/23/21 7 N/A 1 soil sample (6-7 feet) SB14-2021 6 10/23/21 4.5 N/A 1 soil sample (4-5 feet)

SB14a-MW11-2021 6 10/23/21 4.5 2.8-7.8 1 soil sample (4.5-5.5 feet) 2 GW samples (7/31; 10/5)

SB15-MW12-2021 10 10/22/21 6.31 5.8-10.8 1 soil sample (7-8 feet bgs) 2 GW samples (7/31; 10/5)

SB16-MW13-2021 10 10/22/21 6.46 5.0-10.0 1 soil sample (4.5-5 feet) 2 GW samples (7/31; 10/5)

SB17-MW14-2021 11 10/22/21 6.33 5.5-10.5 1 soil sample (5.5-6 feet) 2 GW samples (7/31; 10/5)

SB18-MW15-2021 10 10/22/21 7.91 5.5-10.5 1 soil sample (6-7 feet) 1 GW sample (10/5)

SB19-MW16-2021 10 10/22/21 4.5-5 3.5-8.5 1 soil sample (4-5 feet) 2 GW samples (7/31; 10/5)

3.6 WORK PLAN DEVIATIONS

Soil borings SB1, SB2, and SB3 were not drilled due to utility conflicts in the planned locations. A deviation notice (Field Change Notice) was submitted to BIA and ADEC for the elimination of these boring/sampling locations. A copy of the approved notice is provided in Appendix B. As noted above, the locations of the potential interfering utilities around the northwest side of the school are shown on Figure 3.

In the July 2022 sampling event, a vehicle was parked over well MW15; unfortunately, a resident in the adjacent house was not available to move the vehicle and a sample was not obtained.

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3.7 DECONTAMINATION

Non-dedicated, down-well sampling equipment was decontaminated between wells, including all stainless-steel bladder pump components, the water level meter, and the interface probe. The pumps were appropriately disassembled for the decontamination process. Similarly, soil sampling and drilling equipment including drilling cores, sampling spoons, and bowls were also decontaminated between each boring location. Decontamination procedures included an Alconox wash and deionized water rinse. Disposable tubing and the Macro-Core liners (for the soil borings) were used for sampling efforts.

3.8 WASTE MANAGEMENT

IDW generated during the three field events included soil cuttings, purge and decontamination water, and solid wastes such as nitrile gloves and paper towels. These wastes were managed as follows:

• Solid wastes. For each of the three events, these were placed in garbage bags and disposed as typical solid waste which is finally disposed at the City of Kotzebue landfill.

• Decon and purge water. This was containerized in a drum and sampled for waste characterization purposes. The results for this water are summarized in Table 6 and included in Appendix G. No analytes were detected at concentrations above the levels of quantitation (LOQs) in this water. The drum is currently stored outside and likely frozen.

It will be surface disposed once it melts in spring/early summer 2023.

• Soil cuttings. Soils from the borings and well installations were containerized in 5-gal drums labeled according to each boring/well. Separate requests for disposal were submitted to ADEC for these materials according to the detected compounds in each boring; copies of the disposal approvals are provided in Appendix C:

o Cuttings with low/no detects (Appendix C-1). Cuttings from borings SB07, SB10, SB12, SB17, and SB18 had low-level or no detections of just petroleum (non-chlorinated) compounds that enabled these materials to be disposed in the Kotzebue Landfill, per the approval from ADEC.

o Cuttings with higher levels of detections (Appendix C-2). Cuttings from borings SB05, SB06, SB08, SB09, SB11, SB13, SB14a, SB16, and SB19 had detections of petroleum compounds that could not be disposed in the Kotzebue landfill and therefore required transport back to Anchorage for disposal. These materials were disposed with Anchorage Sand and Gravel (Alaska Soil Recycling). This disposal occurred in July 2022.

o Cuttings with potential chlorinated compound detections (Appendix C-3). The potential detection of trichlorofluoromethane (R-11 refrigerant) in borings SB04, SB14, and SB15 (see Table 5) meant these soils could not be immediately managed

Kotzebue, Alaska Page 17 by Alaska Soil Recycling. The initial detection in these borings was at concentrations below the LOQ (above the limit of detection, LOD). Additional sampling, performed in July 2022, demonstrated that these soils did not contain any chlorinated compounds (results provided in Appendix G and Table 5). The approved and completed transport form is provided in Appendix C-3. These soils were disposed appropriately by U.S. Ecology.

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4 INVESTIGATION RESULTS

The section summarizes and provides discussion of notable observations and analytical soil and groundwater sampling results from the site investigation at the Former IHS/BIA Hospital-School.

4.1 SOIL SAMPLING RESULTS

Field screening and analytical data from soil sampling are summarized in the following subsections.

4.1.1 Geology

The sixteen soil borings performed around the former BIA school and hospital generally encountered unconsolidated gravel, sand, and silt materials to their final depth. This material is consistent with the general fill materials used throughout the Kotzebue area to enable construction within the area. Peat and organic material were intermittently encountered at a general depth of four feet bgs (SB08; SB12; SB19). Minimal ice or permafrost was encountered.

Foam insulation was encountered in SB14 at three feet bgs, indicating that this area had previously been disturbed. The foam encountered in SB14 coupled with the known utilities in the area around SB01, SB02, and SB03 led to the elimination of these three borings. City of Kotzebue personnel also had significant concerns related to these three boring locations and the potential for damage to these utilities.

4.1.2 Field Screening

To provide a qualitative understanding of the potential fuel related impacts in the site soils, PID field screening measurements and visual/olfactory field observations are documented on the soil boring logs in Appendix D. A strong petroleum, oil, and lubricant (POL) odor was noted in borings SB05, SB06, SB08, SB09, SB14, and SB19. The petroleum odor was generally associated with sandy material in proximity to the groundwater table. The elevated PID results were observed two feet or more below ground surface. Table 4 provides a summary of the PID readings. As noted, only a few of the borings had PID readings above 50 and those generally are found in areas immediately adjacent to the pipeline and at the location to the west of Bison Street (SB14).

Where PID readings are above 50, the greater values are generally located at the deeper depths and in soils near the zone where groundwater is periodically in contact with the soil. It is important to note that the PID results were not used as any form of an action level, but rather to simply provide qualitative information on the general presence/absence of impacts.

4.1.3 Soil Analytical Results

Complete soil analytical results are included in Appendix G; samples with concentrations of specific compounds above the applicable project screening level (PSLs) are shown on Figure 4 and highlighted in Table 5. None of the soil had individual VOC or PAH analyte detections that

Kotzebue, Alaska Page 20 exceeded their respective arctic zone soil cleanup levels (i.e., the PSLs), as identified in the prior section.

While many of the soil boring samples detected DRO and RRO, only one of the 18 samples had an exceedance. DRO was detected in SB04 (4.5-5 ft bgs) at a concentration of 18,400 milligrams per kilogram (mg/kg); the PSL is 12,500 mg/kg.

Table 4. Soil Boring PID Readings

Borehole

ID

Depth (ft bgs)

PID

Reading

Borehole

ID

Depth (ft bgs)

PID

Reading

Borehole

ID

Depth (ft bgs)

PID

Reading

SB04-

0-2 10.2

SB11-

0-2 13

SB16-2021

0-2 0.2 2-4 13.5 2-4 7.7 2-4 0.2 4-5 16 4-5 11.3 4-6 0.2

SB05-

0-2 19.7 5-7 9.6 6-8 2

2-4 149 SB12-

0-2 4.2 8-10 5 4-5 324.6 2-4 6

SB17-2021

0-2 0.2

SB06-

0-2 0.1 4-5 6.8 2-4 0.2

2-4 0.3 SB13-

0-2 11.2 4-6 0.4 4-6 297 2-4 12.8 6-8 0.5

SB07-

0-2 9.9 4-5 10 8-10 0.4

2-4 8.7 SB14-

0-2 2.3

SB18-2021

0-2 0.4 4-5 7.2 2-4 8 2-4 0.5

SB08-

0-2 8.1 4-5 159 4-6 0.3 2-4 6.5 SB14a-

0-2 76.9 6-8 0.8 4-5 16 2-4 149 8-10 0.7

SB09-

0-2 12.7 4-5 450

SB19-2021

0-2 0.5 2-5 8.8

SB15-

0-2 0.4 2-4 28 5-7 171 2-4 0.4 4-6 5.5 7-9 27.7 4-6 0.4 6-8 23

SB10-

0-2 9.7 6-8 308 2-4 13.6 8-10 197 4-6 10.6

Note: Color coding is as follows:

Green – detections from 0 – 5; Yellow – 5 – 100; Orange – 100 – 300; Red – above 300

4.2 GROUNDWATER INVESTIGATION RESULTS

Two rounds of groundwater samples were collected in 2022: in late July and in early October.

The results from these samples are summarized in the following subsections.

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4.2.1 Groundwater Quality Field Parameters

The final water quality measurements from the purging of each well are summarized in Table 6.

Water levels were recorded in each sampling event with the water level tape; these measurements are also provided in Table 7.

4.2.2 Groundwater Analytical Results

Groundwater samples were obtained from each well during both sampling events (July and October 2022). Samples were kept on ice and under Chain-of-Custody (COC) procedures for delivery to the laboratory, SGS North America Inc. in Anchorage, Alaska. The following subsections highlight the results from the analyses performed. Table 6 provides a summary of the analytical results for both sampling events.

For both the July and October 2022 sampling events the samples arrived at the laboratory with temperatures exceeding the acceptable range for VOC samples. The standard temperature is set at 6°C; however, the recorded temperatures for the June and July samples were 12.7°C and 15°C, respectively. It is important to consider the potential impacts of elevated temperatures on these samples:

• Increased volatility: Higher temperatures can enhance the volatility of VOCs, causing them to evaporate at a faster rate.

• Compound degradation: Elevated temperatures can lead…