Aircraft Mishap RI Report_FINAL 2022.pdf

THE MANNIK & SMITH GROUP, INC. i Aircraft Mishap Report_20220921.docx

REMEDIAL INVESTIGATION REPORT

AIRCRAFT MISHAP SITE

HIAWATHA NATIONAL FOREST

DELTA COUNTY, MICHIGAN

PROJECT: XGFG212004

SEPTEMBER 2022

PREPARED FOR:

WISCONSIN AIR NATIONAL GUARD

115TH FIGHTER WING

3110 MITCHELL STREET

MADISON, WISCONSIN 53704

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TABLE OF CONTENTS

Remedial Investigation Report

Aircraft Mishap Site Hiawatha National Forest Delta County, Michigan

SECTION: PAGE NO.:

1.0 INTRODUCTION

1.1 Site Description

1.2 Geologic Setting

2.0 OBJECTIVES AND SCOPE OF WORK

3.0 SUBSURFACE INVESTIGATION METHODOLOGY

3.1 Utility Clearance

3.2 Soil Boring Advancement and Soil Sampling

3.3 Temporary Monitoring Well Installation and Groundwater Sampling

4.0 INVESTIGATION FINDINGS AND CONCLUSIONS

4.1 Project Area Hydrogeology

4.2 Soil Sample Analytical Results

4.3 Groundwater Sample Analytical Results

5.0 RISK-BASED CORRECTIVE ACTION EVALUATION

5.1 Potential Receptors and Exposure Pathways

5.2 Exposure Pathway Evaluation

6.0 CONCLUSIONS AND RECOMMENDATIONS

FIGURES

Figure 1 Site Location Figure 2 Site Features Figure 3 Groundwater Flow Potential Figure 4 Soil Sample Results Figure 5 Groundwater Sample Results

TABLES

Table 1 Temporary Monitoring Well Construction and Elevation Data Table 2 Soil Boring Analytical Results Table 3 Groundwater Analytical Results

APPENDICES

Appendix A Soil Boring Logs Appendix B Field Sampling Sheets Appendix C Photograph Log Appendix D Laboratory Analytical Reports

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1.0 INTRODUCTION

The Mannik & Smith Group, Inc. (MSG) has prepared this Remedial Investigation (RI) Report for the Aircraft Mishap Site located in the Hiawatha National Forest in Delta County, Michigan (Site). This RI Report has been prepared for Project XGFG 212004 in accordance with Contract No. 47QRAA20D006A, Order No. W50S9F21F0008 in response to a request from the 115th Fighter Wing (115FW), Wisconsin Air National Guard.

This report summarizes the results of the RI activities that were conducted to determine the nature and extent of impact and assess potential risks posed by petroleum-contaminated soil and groundwater.

1.1 Site Description

On December 8, 2020, an F-16 aircraft crashed during a nighttime training exercise. The crash site is in eastern Delta County, near the Schoolcraft County line. The Site is located in the northwest quarter of Section 28, Township 43 North, and Range 18 West. Figure 1, Site Location, depicts the Site location relative to nearby roads and major geographic features. Land use at and within one mile of the Site is undeveloped woodland that is part of the Hiawatha National Forest.

The aircraft was carrying an estimated maximum 7,000 pounds of Jet-A fuel onboard, and potentially approximately five gallons of oil and 12 to 15 gallons of hydraulic fluid. Information provided by the 115FW indicates that the site was excavated to a depth of approximately 30 feet below the ground surface (ft bgs).

Removed soil was sifted to recover crash debris then returned to the excavation. Six soil samples were taken at a depth of approximately 1-foot below the ground surface from the backfilled soil. Groundwater was reportedly not encountered in the excavation.

1.2 Geologic Setting

According to the map Quaternary Geology of Michigan (compiled in 1982 by W.R. Farrand and published by the Michigan Geological Survey), the Site is located in an area mapped as glacial outwash sand and gravel and postglacial alluvium. According to the United States Department of Agriculture’s (USDA) website, websoilsurvey.sc.egov.usda.gov, the soils identified at the Site primarily consist of Kalkaska sand, which is very deep, somewhat excessively drained soil that formed in sandy drift on outwash plains, valley trains, moraines, and stream terraces. Slopes range from 0 to 70 percent. Mean annual precipitation is about 760 millimeters (mm), and the mean annual temperature is about 6 degrees Celcius. Based on the map Bedrock Geology of Northern Michigan (Reed, Robert C., and Daniels, Jennifer, 1987), the underlying bedrock is the Late Ordovician Big Hill Dolomite Formation, which includes the sedimentary carbonates limestone and dolomite.

A wetland area is the nearest surface water body with respect to the Site and is located approximately 1,900 feet to the southeast in the direction of groundwater flow potential at the Site.

Depth to groundwater at the Site has been documented between approximately 12 and 22 ft bgs and groundwater flow has been determined to be generally to the southeast. Refer to Section 4.1 of this report for more hydrological information relevant to the Site.

2.0 OBJECTIVES AND SCOPE OF WORK

The purpose of the RI activities was to identify the nature and extent of petroleum impact and assess risks, with the overall project objective to achieve the goal of a “No Further Action” (NFA) status with the Michigan Department of Environment, Great Lakes, and Energy (EGLE) for petroleum impact related to the mishap. MSG developed a Work Plan in consultation with the 115FW to implement the RI activities. The Work Plan described the design and

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implementation of systems for the collection of environmental samples and described the data quality objectives, sampling procedures, analytical methods/procedures, data handling, quality assurance/quality control (QA/QC) measures, and documentation procedures.

Between May 2 and 4, 2022, MSG implemented the field work portion of the Work Plan to characterize Site conditions.

The Work Plan implementation included:

Investigative activities, including:

o Coordinating access to the Site and other pre-work activities.

o Direct-push soil sampling at the locations depicted on Figure 2, Site Features. Groundwater was encountered in all borings so groundwater samples were also collected using temporary monitoring wells. Based on field screening, depth to groundwater measurements, and a top of temporary well casing survey during implementation of the initial nine borings (B1 through B9), two additional step-out borings (B10 and B11) were added to ensure delineation of the apparent extent of impact based on the calculated groundwater flow potential direction.

o Laboratory analysis of collected soil and groundwater samples for petroleum volatile organic compounds (PVOCs).

o Review of existing soil sampling data provided by the 115FW.

o Review of analysis results from this investigation and conducting an exposure pathway evaluation and risk assessment.

Preparation of an Investigation Results Summary and review of the RI results with the 115FW.

Preparation of this RI Report which summarizes the work conducted and results obtained.

MSG used the RI findings and prior information to prepare this RI Report, including a Risk-Based Corrective Action (RBCA) evaluation and recommendations.

3.0 SUBSURFACE INVESTIGATION METHODOLOGY

The following subsections provide a description of the field methodologies employed by MSG during the completion of the RI activities.

3.1 Utility Clearance

Proposed investigative locations were cleared of potential underground utility lines prior to mobilization.

Michigan’s one-call MISSDIG system was contacted by MSG’s subcontracted drilling firm to have utilities, if present, marked at the Site in advance of the start of investigative work. MISSDIG was contacted at least 72 hours prior to commencing intrusive activities in accordance with Public Act 174, Miss Dig Underground Facility Damage Prevention and Safety Act.

3.2 Soil Boring Advancement and Soil Sampling

Between May 2 and 4, 2022, MSG advanced 11 soil borings (B1 through B11) within and around the mishap impact area to characterize soil and groundwater conditions at the Site. The soil borings were advanced to a maximum depth of 28 ft bgs. Soil boring locations are depicted on Figure 2, Site Features.

Soil boring locations were selected to characterize Site conditions based on review of available historical information from the 115FW. Locations were chosen to identify and characterize the contaminant source area, correlate soil lithology, determine the elevation of the groundwater potentiometric surface, identify potential migration pathways, and delineate the spatial extent of soil and groundwater contamination.

Soil borings were advanced using a track-mounted Geoprobe® with a dual-tube sampling system. Direct push soil borings were advanced using a 5-foot long, 1.5-inch diameter Macro-Core® sampling device to collect

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continuous soil samples at all borings using a motor-driven hydraulic hammer to the desired depth. Soil borings were continuously profiled from the ground surface to the terminus of the borehole. A dedicated, clear polyvinyl chloride (PVC) liner was placed within the sampler between each sample interval. Soil samples were field-screened for the presence of volatile organic compounds (VOCs) using a photoionization detector (PID) and classified in general accordance with the Unified Soil Classification System (USCS).

Soil boring depths ranged from 25 ft bgs at boring B1 near the center of the mishap impact, to 28 ft bgs at B9 which was the highest topographic location of the investigation, to 20 ft bgs at B11, which was the furthest downhill and lowest topographic location.

Two soil samples were collected from each boring location (B1 through B11) that generally consisted of a shallow and a deeper soil sample above the saturated zone and capillary fringe. The shallow intervals selected for laboratory analysis at each boring location were generally guided by field screening results indicative of potential petroleum impact (if any); and the deeper soil samples were collected above the saturated zone to evaluate the vertical extent of impacted soils below the ground surface at the mishap impact area. Soil samples collected by MSG were handled and preserved in accordance with EGLE Remediation and Redevelopment Division (RRD) Operational Memorandum No. 2, Attachment 4 entitled Sample Preservation, Sample Handling and Holding Time Specifications, dated October 22, 2004 and US Environmental Protection Agency (USEPA) Method 5035, Closed-System Purge-And-Trap and Extraction for Volatile Organics in Soil and Waste Samples.

Soil samples were submitted to ALS Environmental Laboratory in Holland, Michigan for analysis of PVOCs following EGLE guidance appropriate for light distillate oils using USEPA Method 8260 for benzene, toluene, ethylbenzene, xylenes (collectively BTEX) and trimethylbenzenes, and USEPA Method 8270 for polynuclear aromatic hydrocarbons (PNAs).

All drill rods and non-disposable sampling equipment were cleaned (decontaminated) by washing with a water/Alconox® solution and thoroughly rinsing with potable water. Following completion, all borings were abandoned with soil cuttings from the respective boring and bentonite chips. Surface restoration consisted of raking disturbed areas to smooth the ground surface upon completion. Spent personal protective equipment (PPE) and waste generated by sampling activities were bagged and removed from the Site for disposal by MSG personnel.

3.3 Temporary Monitoring Well Installation and Groundwater Sampling

During the subsurface investigation, groundwater was encountered in each boring. Therefore, a temporary monitoring well was installed in each soil boring to identify potential source areas, characterize groundwater conditions, delineate the extent of impact, and determine the groundwater flow potential direction. The temporary monitoring well labeling corresponded with the respective soil boring location identification number.

Each temporary monitoring well consisted of 1-inch diameter polyvinyl chloride (PVC) well material with a 5-foot long screen set to straddle the groundwater table surface. The depth to groundwater was recorded in each monitoring well prior to sampling. The depth to groundwater was recorded between approximately 12 and 22 ft bgs, with ground surface elevation changes generally accounting for the range in depth measurements.

After installation of the first nine temporary monitoring wells (B1 through B9), static water levels were measured using an electronic water level probe to determine the depth to groundwater and an elevation survey was completed to determine the top of casing (TOC) elevations for the temporary monitoring wells.

The elevations were plotted to determine the groundwater flow potential direction and aid in selecting two additional sampling locations (B10 and B11). The groundwater elevations from the two additional temporary monitoring wells were measured and surveyed in the same manner as the first nine temporary monitoring

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wells. The tabulated measurements and resulting groundwater elevations are summarized in Table 1, Temporary Monitoring Well Construction and Elevation Data.

Groundwater samples GW1 through GW11 were collected at each respective location B1 through B11 using low flow sampling methods. Geochemical field parameters were recorded on field sheets including dissolved oxygen (DO), pH, oxidation reduction potential (ORP), conductivity, temperature, and turbidity. Field parameters were measured with a YSI ProDSS water quality meter equipped with a flow-through cell prior to the time of groundwater sample collection. Groundwater was pumped directly into laboratory-provided sample containers. Following EGLE guidance, one (1) duplicate groundwater sample per 10 samples and analytical group and one (1) matrix spike/matrix spike duplicate (MS/MSD) per 20 groundwater samples and analytical group were collected for QA/QC procedures.

Collected samples were handled and preserved in general accordance with EGLE RRD Operational Memorandum No. 2, Attachment 4 dated October 22, 2004. Groundwater samples were submitted to ALS Environmental Laboratory in Holland, Michigan for analysis of PVOCs following EGLE guidance appropriate for light distillate oils using USEPA Method 8260 for BTEX and trimethylbenzenes and USEPA Method 8270 for PNAs. Refer to Section 4.3 of this report for the analytical results discussion.

After the collection of groundwater samples, the temporary well materials were removed from the ground, all borings were abandoned with soil cuttings and bentonite chips, and the ground surface was restored by raking it smooth. Soil boring logs are included in Appendix A, Soil Boring Logs. Temporary monitoring well sampling field sheets are included in Appendix B, Field Sampling Sheets. Representative photographs are provided in Appendix C, Photograph Log.

4.0 INVESTIGATION FINDINGS AND CONCLUSIONS

The following subsections provide a discussion of the RI results.

4.1 Project Area Hydrogeology

Soils encountered were generally sand with varying amounts of silt and clay, with clay more predominant in the southern and eastern borings. Soil boring logs are included in Appendix A, Soil Boring Logs.

The static groundwater levels ranged from approximately 12 and 22 ft bgs, with ground surface elevation changes generally accounting for the range in depth measurements. The groundwater was encountered in unconfined sand units which were present from approximately 4 to 25 ft bgs. The wide range could be a result of soil disturbance resulting from the initial excavation at the impact location and backfill of Site soils to remove the bulk of the mishap debris.

The groundwater flow potential direction was determined to be to the southeast, with only 0.24 feet in groundwater elevation change from boring B9 (located in the northwestern portion of the investigation) to boring B11 (located in the southeastern portion of the investigation). The groundwater flow potential direction mirrors the general topographic trend at the Site. Refer to Figure 3, Groundwater Flow Potential which depicts the temporary monitoring well locations and groundwater contours for the May 2022 sampling event.

Groundwater velocity was calculated using Darcy’s equation:

Vgw = Ki/n Where: Vgw = groundwater velocity

K = average hydraulic conductivity in feet per day (ft/day)

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i = horizontal hydraulic gradient in feet per foot (ft/ft) n = effective porosity

A hydraulic conductivity value of 17 ft/day and an effective porosity of 30% (0.3) were used for the purpose of determining groundwater velocity. These values are estimated and are based on values for fine to medium grained silty sand taken from Groundwater (Freeze and Cherry, 1979).

The groundwater surface elevations for B9/GW9 (83.75 ft) and B11/GW11 (83.51 ft) as measured between May 3 and 4, 2022, as well as the respective horizontal distance between the locations (148.25 ft), were used to determine the horizontal hydraulic gradient of 0.001619 ft/ft. As a result, groundwater flow velocity was calculated to be approximately 0.092 ft/day (33.5 feet per year) to the southeast.

With these measured and calculated values, groundwater at the Site could take up to 56 years to reach the nearest surface water body, a wetland area located approximately 1,900 feet to the southeast of the Site.

4.2 Soil Sample Analytical Results

MSG submitted a total of 24 soil samples including two QA/QC samples for analysis of PVOCs and PNAs following EGLE guidance appropriate for light distillate oils. Due to a lab error, the PNA analyses for the soil samples from May 3, 2022 were re-run. Analysis results are summarized in the attached Table 2, Soil Boring Analytical Results and are depicted graphically on the attached Figure 4, Soil Sample Results. Laboratory reports are provided in Appendix D, Laboratory Analytical Reports.

Soil samples collected from borings B1 and B4 near the center of the impact area exceeded EGLE Residential and Nonresidential Drinking Water Protection Criteria (DWPC) and Groundwater / Surface Water Interface Protection Criteria (GSIPC). The shallow soil sample from B5 also near the center of the impact area exceeded GSIPC. Soil samples from the remaining surrounding boring locations did not exceed EGLE criteria, thereby defining the horizontal limits of impact. For vertical delineation, the 8 to 10 ft bgs sample at B1 and the 12 to 14 ft bgs sample at B5 did not exceed EGLE criteria while at B4 groundwater was encountered at approximately 16.3 ft bgs, providing the vertical limit of potential soil impact at that location. Refer to the summary provided by Table 4.2, Soil Exceedance Summary Table below listing the soil sample criteria exceedances. Laboratory analysis of the remaining soil samples either did not detect contaminants or did not exceed EGLE criteria. For the complete tabulation of soil analysis results refer to Table 2, Soil Boring Analytical Results. Please note that the samples from May 3, 2022 that were re-run by the laboratory show both sets of results, the initial value followed by the re-run value that has an “H” qualifier indicating that the holding time had been exceeded before the re-run was completed.

Assuming the affected area exceeding EGLE criteria around B1, B4, and B5 is approximately 35 ft wide, 45 ft long, and an average of 12 ft deep, the volume of affected soil would equal approximately 700 cubic yards.

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Table 4.2 Soil Exceedance Summary Table

4.3 Groundwater Sample Analytical Results

MSG collected a total of 13 groundwater samples including two QA/QC samples between May 2nd and 4th, 2022 for analysis of PVOCs and PNAs following EGLE guidance appropriate for light distillate oils. Analysis results are summarized in the attached Table 3, Groundwater Analytical Results and are depicted graphically on the attached Figure 5, Groundwater Sample Results. Laboratory reports are provided in Appendix D, Laboratory Analytical Reports.

1,2,4-Trimethylbenzene 1,3,5-Trimethylbenzene Total Xylenes 2-Methylnaphthalene Naphthalene

4 - 6 ft 5/2/2022 24,000 [1,2,3] 7,500 [1,2,3] 16,000 [1,2,3] 13,000 [3] 3,400 [3]

8 - 10 ft 5/2/2022 60 <110 <100 120 34

4 - 6 ft 5/3/2022 <39 <130 <120 <4.8 / <4.8 H <4.8 / <4.8 H

12 - 14 ft 5/3/2022 <33 <110 <99 <4.3 / <4.3 H <4.3 / <4.3 H

0 - 2 ft 5/2/2022 <40 <130 <120 <4.7 <4.7

10 - 12 ft 5/2/2022 72 <92 89 <11 <11

4 - 6 ft 5/2/2022 22,000 [1,2,3] 8,600 [1,2,3] 11,000 [1,2,3] 8,700 [3] 1,400 [3]

12 - 14 ft 5/2/2022 600 [3] 190 720 570 42

6 - 8 ft 5/3/2022 58 <110 <100 390 / 11,000 H [3] 74 / 1,700 H [3]

6 - 8 ft Duplicate 5/3/2022 <36 <120 <110 1,400 / 960 H 340 / 150 H

12 - 14 ft 5/3/2022 <31 <100 <94 <4.3 / <4.3 H <4.3 / <4.3 H

8 - 10 ft 5/3/2022 <37 <120 <110 6,700 / <4.6 H 1,700 / <4.6 H

8 - 10 ft Duplicate 5/3/2022 <32 <110 <97 8.9 / <4.4 H <4.4 / <4.4 H

13 - 15 ft 5/3/2022 <29 <96 <87 <4.2 / <4.2 H <4.2 / <4.2 H

2 - 4 ft 5/2/2022 <32 <110 <95 <4.6 <4.6

9 - 11 ft 5/2/2022 <29 <98 <88 <4.9 <4.9

2 - 4 ft 5/2/2022 <38 <130 <110 <4.8 <4.8

15 - 17 ft 5/2/2022 <32 <110 <96 <4.1 <4.1

6 - 8 ft 5/3/2022 <35 <120 <100 13,000 / <4.6 H 3,200 / <4.6 H

18 - 20 ft 5/3/2022 <34 <110 <100 92 / <4.3 H 26 / <4.3 H

3 - 5 ft 5/4/2022 <36 <120 <110 <4.6 <4.6

8 - 10 ft 5/4/2022 <31 <100 <94 <4.8 <4.8

3 - 5 ft 5/4/2022 <34 <110 <100 <4.3 <4.3

8 - 10 ft 5/4/2022 <43 <140 <130 <12 <12

Trip Blank Not Applicable Not Applicable <30 <100 <90 NM NM

2,100 1,800 5,600 57,000 35,000

2,100 1,800 5,600 170,000 100,000

570 1,100 980 4,200 730

4,300,000 2,600,000 6,300,000 2,700,000 250,000

21,000,000 16,000,000 46,000,000 1,500,000 300,000

25,000,000 19,000,000 54,000,000 1,800,000 350,000

32,000,000 32,000,000 410,000,000 8,100,000 16,000,000

100,000,000 100,000,000 1,000,000,000 26,000,000 52,000,000

110,000 94,000 150,000 NA NA

Bold indicates contaminant was detected

“ID” means insufficient data. "NM" means not measured.

"NA" means not available. "PNAs" means Polynuclear Aromatic Hyodrcarbons

“NLL” means hazardous substance is not likely to leach. "ug/kg" means micrograms per kilogram

“NLV” means hazardous substance is not likely to volatilize under most conditions.

Only compounds with criteria exceedances are listed.

Notes

[7] Residential Direct Contact Criteria (DCC)

[8] Nonresidential DCC

[9] Soil Saturation Concentration (Csat) Screening Level

[4] Residential Soil Volatilization to Indoor Air Inhalation (SVIIC) Criteria

[5] Residential Infinite Source Volatile Soil Inhalation Criteria (VSIC)

[6] Nonresidential Infinite Source VSIC

Bold and gray shading indicates contaminant exceeded the listed criteria.

"H" means re-run sample extracted outside of holding time due to lab error. Results should be considered estimated.

Due to a lab error, the semivolatile organic analyses were re-run for the soil samples from 5/3/22. Both sets of results are listed, with the re-run results used for criteria comparison.

Organics-Volatiles (ug/kg) Organics- PNAs (ug/kg) Location Sample Depth Date Collected

B1

B2

[1] Residential Drinking Water Protection (DWP) Criteria

[2] Nonresidential Drinking Water Protection (DWP) Criteria

[3] Groundwater Surface Water Protection (GSIP) Criteria

B9

B10

B11

B3

B4

B5

B6

B7

B8

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Groundwater samples GW-1, GW-3, and GW-4, collected at boring locations B1, B3, and B4, respectively, exceeded EGLE Residential and Nonresidential Drinking Water Criteria (DWC) and Groundwater / Surface Water Interface Criteria (GSIC). Groundwater samples from surrounding and hydraulically downgradient locations did not exceed EGLE criteria, providing horizontal delineation of the affected groundwater. Vertical delineation was provided by the field screening results from B1 near the center of the impact area which indicated declining PID responses with depth into the groundwater table, as expected for a light distillate petroleum product. Refer to the summary provided by Table 4.3, Groundwater Exceedance Summary Table below listing the groundwater sample criteria exceedances.

Table 4.3 Groundwater Exceedance Summary Table

Laboratory analysis of the remaining groundwater samples did not detect contaminants or did not exceed EGLE criteria. For the complete tabulation of groundwater analysis results refer to Table 3, Groundwater Analytical Results.

1,2,4-Trimethylbenzene 1,3,5-Trimethylbenzene Benzene Ethylbenzene Toluene Total Xylenes

GW-1 17' - 22' 5/2/2022 110 [1,2,3] 98 [1,2,3] <1.0 4.5 <1.0 120 [3]

GW-2 15' - 20' 5/3/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

14.6' - 19.6' 5/3/2022 230 [1,2,3] 76 [1,2,3] 40 [1,2] 51 [3] 280 [3] 610 [1,2,3]

14.6' - 19.6' Duplicate 5/3/2022 230 [1,2,3] 82 [1,2,3] 47 [1,2] 57 [3] 290 [3] 630 [1,2,3]

GW-4 15' - 20' 5/3/2022 350 [1,2,3] 120 [1,2,3] 36 [1,2] 180 [1,2,3] 430 [3] 1,200 [1,2,3]

GW-5 16' - 21' 5/4/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

GW-6 18' - 23' 5/3/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

GW-7 13' - 18' 5/2/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

GW-8 17.5' - 22.5' 5/3/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

GW-9 20.4' - 25.4' 5/3/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

GW-10 12.5' - 17.5' 5/4/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

15' - 20' 5/4/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

15' - 20' Duplicate 5/4/2022 <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

Trip Blank -- -- <1.0 <1.0 <1.0 <1.0 <1.0 <3.0

63 72 5 74 790 280

63 72 5 74 790 280

17 45 200 (X) 18 270 49

56,000 61,000 5,600 110,000 530,000 190,000

56,000 61,000 35,000 170,000 530,000 190,000

“NA” means a criterion or value is not available or, in the case of background, not applicable.

Letters in criteria columns refer to Footnotes of the EGLE criteria tables.

Only compounds with criteria exceedances are listed.

Bold and gray shading indicates contaminant exceeded the listed criteria.

"JT" means the hazardous substance may be present in several isomer forms. The VIAP screening level may be used for the individual isomer provided that it is the sole isomer detected;

however, when multiple isomers are detected in a medium, the isomer-specific concentrations must be added together and compared to the most restrictive VIAP screening level of the detected isomers.

Organics-Volatiles (ug/L)

“ID” means insufficient data to develop criterion.

“NLV” means hazardous substance is not likely to volatilize under most conditions.

"NM" means not measured.

"ug/L" means micrograms per liter

"mg/L" means milligrams per liter

Bold indicates contaminant was detected

Notes

[1] Residential Drinking Water Criteria

Location Sample Depth (ft) Date Collected

GW-3

GW-11

[2] Nonresidential Drinking Water Criteria

[3] Groundwater Surface Water Interface Criteria

[4] Residential Groundwater Volatilization to Indoor Air Inhalation Criteria

[5] Nonresidential Groundwater Volatilization to Indoor Air Inhalation Criteria

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5.0 RISK-BASED CORRECTIVE ACTION EVALUATION

Using data and information obtained during RI activities, MSG completed a RBCA evaluation, which included:

1) Identifying potential receptors;

2) Evaluating potential exposure pathway relevance; and,

3) Determining applicable criteria.

EGLE criteria under Part 201 of Michigan’s Natural Resources and Environmental Protection Act, being PA 451 of 1994, as amended (NREPA), are applicable if it is reasonable and relevant for the corresponding exposure pathway to be or to become complete. The preliminary RBCA evaluation provided below identifies the potential hazards that may arise from the presence of impacted media as well as systemic human and ecological risks posed by the Site contaminants.

5.1 Potential Receptors and Exposure Pathways

MSG conducted an assessment to determine the potential receptors that could be exposed to chemicals impacting the area. The potential receptor assessment included a review of the current conditions, the foreseeable future intended use of the areas, and foreseeable human and ecological receptors. Research and reconnaissance conducted, and findings therefrom, include:

Surrounding land uses: The Site is located in a remote wooded portion of the Hiawatha National

Forest. Review of aerial imagery suggests that the nearest structure is located approximately 1 mile to the southwest.

Reconnaissance for nearby surface water bodies to which groundwater could be venting: Based on aerial imagery review and conversation with Mr. Charles Marsh, District Ranger for the US Forest

Service, the nearest potential surface water is a wetland area approximately 1,900 feet to the southeast in the direction of the groundwater flow potential. Using an estimated hydraulic conductivity of 6x10-5 meters per second for fine sand and the hydraulic gradient between B9 and B11, MSG calculated an estimated groundwater flow rate of 33.5 feet per year. This suggests that groundwater from the Site could require approximately 56 years to reach the nearest surface water body.

Potential groundwater receptors: MSG conducted a search for available water well records using

EGLE’s Scanned Water Well Records system https://www.egle.state.mi.us/well-logs/, Wellogic system https://www.egle.state.mi.us/wellogic/Login.aspx?ReturnUrl=%2fwellogic%2fdefault.aspx, and Water Well Viewer https://www.mcgi.state.mi.us/waterwellviewer/. In particular, records for

Sections 20, 21, 28, and 29 of Township 43 North, Range 18 West of Garden Township, Delta County were searched. No water wells were identified within 1 mile of the Site.

Potential inhalation and direct contact receptors: As indicated above, the nearest known structure is approximately 1 mile from the Site. The soil analysis results did not exceed EGLE Infinite Source

Volatile Soil Inhalation Criteria (i.e. ambient air inhalation) or Direct Contact Criteria.

https://www.egle.state.mi.us/well-logs/ https://www.egle.state.mi.us/wellogic/Login.aspx?ReturnUrl=%2fwellogic%2fdefault.aspx https://www.mcgi.state.mi.us/waterwellviewer/

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5.2 Exposure Pathway Evaluation

Part 201 criteria have been developed to correspond to specific exposure pathways for residential and non-residential land uses. Each of the EGLE soil and groundwater exposure pathways was evaluated for its reasonableness and relevance based on the Site’s general physical setting, land uses, and mechanisms that may expose a receptor to chemical impacts.

While soil and groundwater exceed EGLE criteria protective of drinking water uses, there are no known potentially exposed receptors at or within at least one mile of the Site based on the above factors. Though certain soil and groundwater results at the immediate mishap location exceeded GSIPC or GSIC respectively, the GSI exposure pathway should not be considered relevant given the distance to a surface water body and estimated groundwater travel time. These lead to a conclusion that groundwater is not reasonably expected to vent to surface water at concentrations that exceed generic GSI criteria.

6.0 CONCLUSIONS AND RECOMMENDATIONS

The Site is located in a remote wooded portion of the Hiawatha National Forest. The nearest structure is located approximately 1 mile to the southwest and there are no known drinking water wells within at least one mile of the Site.

The nearest potential surface water is a wetland area approximately 1,900 feet to the southeast, in the direction of the groundwater flow potential.

The spatial extent of soil and groundwater impact above EGLE criteria has been defined. Affected soils near the center of the mishap impact area exceeded DWPC and GSIPC. Approximately 700 cubic yards of soil may exceed EGLE criteria. Affected groundwater exceeds DWC and GSIC. Groundwater from the Site could require approximately 56 years to reach the wetland area to the southeast.

There are no known potentially exposed receptors at or within at least one mile of the Site. The GSI exposure pathway should not be considered relevant given the distance to a surface water body and estimated groundwater travel time.

These lead to a conclusion that groundwater is not reasonably expected to vent to surface water at concentrations that exceed generic GSI criteria.

Based on the RI results, under the purview of EGLE, there are generally two paths to obtain No Further Action (NFA) status for the Site including unrestricted and restricted. An unrestricted NFA status may not be achievable without further action (impacted soil and groundwater remedial action) due to the criteria exceedances at the Site. A restricted NFA without soil and groundwater remediation but relying on a Post Closure Plan with land and resource use controls may be possible if agreeable to US Forest Service and EGLE. The controls would need to include limitations on groundwater use for consumptive purposes and possibly prohibiting structure construction atop the impacted area.

MSG recommends reviewing the results with US Forest Service as the property owner and EGLE to determine their potential concerns and requirements as it relates to obtaining NFA status.

If a restricted NFA is not acceptable, active remedial activities to mitigate residual soil and groundwater impacts may be required.

Active remediation activities could potentially include the following scenarios or combination of scenarios:

Soil removal – Assuming the affected area around B1, B4, and B5 that exceeds EGLE criteria is approximately

35 feet wide, 45 feet long, and an average of 12 feet deep, the volume of soil to be removed and properly disposed could equal approximately 700 cubic yards, or 1,050 tons assuming 1.5 tons per in-place cubic yard.

Verification of remediation soil sampling following EGLE guidance would be required to demonstrate contaminant removal. Excavation and disposal would be the most expedient way to actively address soil

THE MANNIK & SMITH GROUP, INC. 10

contamination but would also likely be the most costly and incur the most disruption to the Site due to truck traffic.

In-situ groundwater remediation – This could entail remedial injections to enhance biodegradation or chemically oxidize the petroleum contamination, or air sparging using a solar powered system to enhance volatilization and biodegradation. Installation of monitoring wells and periodic groundwater sampling and analysis would be required to monitor groundwater conditions over time to demonstrate contaminant reduction and ultimately achievement of groundwater cleanup to below EGLE criteria. This would be the most expedient way to address groundwater contamination but also likely the most costly.

Monitored Natural Attenuation – Under a monitored natural attenuation scenario, installation of permanent monitoring wells with periodic groundwater monitoring and eventual soil re-sampling would be required to confirm natural biodegradation and attenuation of petroleum impacts. Monitored natural attenuation could be considered for groundwater coupled with an active soil remediation approach that removes the source of groundwater impact, conceptually allowing for a more timely completion. Monitored natural attenuation could be the lowest cost scenario but may entail several years of monitoring before remedial goals are met. If attenuation rates are lower than anticipated and groundwater impact above criteria migrates an unacceptable distance from the Site, implementation of a more active remedial method could be required.

The above scenarios were deemed practical given the location and petroleum impact if a restricted NFA is not deemed acceptable and implemented. Other active remedial methods could be considered. Upon achievement of remedial goals (i.e. soil and groundwater contaminant levels below EGLE criteria), an unrestricted NFA Report could then be submitted to EGLE.

FIGURES

Adapted from Wisconsin Air National Guard Figure S1 dated August 2021.

Notes:

Results in RED exceed one or more applicable EGLE criteria as indicated by the footnote shown in [ ] and defined below:

[1] Residential Drinking Water Criteria

[2] Nonresidential Drinking Water Criteria

[3] Groundwater Surface Water Interface (GSI) Criteria

TABLES

Table 1

Temporary Monitoring Well Construction and Elevation Data

Aircraft Mishap Site

Delta County, Michigan

Latitude Longitude

(Decimal degrees) (Decimal degrees)

B1 46.10014690 86.56928151 104.02 100.5 5 19.7 84.30 24.7 5/4/2022 20.30 83.72

B2 46.10019566 86.56928881 NM NM 5 15.7 NM 20.7 5/4/2022 18.36 NM

B3 46.10016688 86.56922727 100.00 99.4 5 15.0 85.02 20.0 5/4/2022 16.30 83.70

B4 46.10010135 86.56929198 100.40 100.0 5 15.0 85.42 20.0 5/4/2022 16.69 83.71

B5 46.10013145 86.56935860 NM NM 5 17.8 NM 22.8 5/3/2022 19.86 NM

B6 46.10026103 86.56915282 102.68 102.0 5 18.7 84.00 23.7 5/3/2022 18.99 83.69

B7 46.10005116 86.56914943 98.28 96.3 5 14.9 83.38 19.9 5/4/2022 14.69 83.59

B8 46.10006509 86.56943706 105.01 102.3 5 20.0 85.06 25.0 5/4/2022 21.30 83.71

B9 46.10022884 86.56940807 106.81 105.8 5 21.7 85.13 26.7 5/3/2022 23.06 83.75

B10 46.10006108 86.56905605 100.04 97.6 5 15.0 85.04 20.0 5/4/2022 16.46 83.58

B11 46.10000107 86.56893192 96.22 95.5 5 15.0 81.22 20.0 5/4/2022 12.71 83.51

Notes:

TOC = Top of Casing

Water level measurements and groundwater elevations are referenced to the top of casing elevation of the temporary monitoring well at B3 with an assumed elevation of 100.00 feet.

Groundwater Elevations measured May 3 and 4, 2022 are depicted on Figure 3 , Groundwater Flow Potential.

Screen

Length

(feet)

Top of Screen

Depth

(feet below TOC)

Top of Screen

Elevation relative to assumed elevation of 100.0' for

B-3 TOC)

Total Depth of Well from TOC

(feet)

Well ID

Top of Casing

Elevation

(relative to assumed elevation of 100.00' for B-3 TOC)

Ground Surface

Elevation relative to assumed elevation of 100.00' for

B-3 TOC)

Measurement

Date

Depth to Water

(feet below TOC)

Groundwater

Elevation

(feet)

Table 1_Aircraft Mishap Site_SWL.xlsx Page 1 of 1

Table 2

Soil Boring Analytical Results

Aircraft Mishap Site

Delta County, Michigan

Location

Sample ID AM-B1-4-6-050222 AM-B1-8-10-050222 AM-B2-4-6-050322 AM-B2-12-14-050322 AM-B3-0-2-050222 AM-B3-10-12-050222

Laboratory ID 22050583-01 22050583-02 22050582-06 22050582-07 22050583-05 22050583-06

Sample Depth 4 - 6 ft 8 - 10 ft 4 - 6 ft 12 - 14 ft 0 - 2 ft 10 - 12 ft

Date Collected 5/2/2022 5/2/2022 5/3/2022 5/3/2022 5/2/2022 5/2/2022

Organics-Volatiles (ug/kg)

1,2,4-Trimethylbenzene 2,100 2,100 570 4,300,000 21,000,000 25,000,000 32,000,000 100,000,000 110,000 24,000 [1,2,3] 60 <39 <33 <40 72

1,3,5-Trimethylbenzene 1,800 1,800 1,100 2,600,000 16,000,000 19,000,000 32,000,000 100,000,000 94,000 7,500 [1,2,3] <110 <130 <110 <130 <92

Benzene 100 100 4,000 1,600 13,000 45,000 180,000 840,000 400,000 <370 <34 <39 <33 <40 <28

Ethylbenzene 1,500 1,500 360 87,000 720,000 2,400,000 22,000,000 71,000,000 140,000 <370 <34 <39 <33 <40 <28

Toluene 16,000 16,000 5,400 330,000 2,800,000 3,300,000 50,000,000 160,000,000 250,000 <370 <34 <39 <33 <40 <28

Total Xylenes 5,600 5,600 980 6,300,000 46,000,000 54,000,000 410,000,000 1,000,000,000 150,000 16,000 [1,2,3] <100 <120 <99 <120 89

2-Methylnaphthalene 57,000 170,000 4,200 2,700,000 1,500,000 1,800,000 8,100,000 26,000,000 NA NA NA <130 <110 NA NA

Naphthalene 35,000 100,000 730 250,000 300,000 350,000 16,000,000 52,000,000 NA NA NA <130 <110 NA NA

Organics- Semivolatiles (ug/kg)

2-Methylnaphthalene 57,000 170,000 4,200 2,700,000 1,500,000 1,800,000 8,100,000 26,000,000 NA 13,000 [3] 120 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Acenaphthene 300,000 880,000 8,700 190,000,000 81,000,000 97,000,000 41,000,000 130,000,000 NA 44 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Acenaphthylene 5,900 17,000 ID 1,600,000 2,200,000 2,700,000 1,600,000 5,200,000 NA 130 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Anthracene 41,000 41,000 ID 1,000,000,000 1,400,000,000 1,600,000,000 230,000,000 730,000,000 NA 23 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Benz[a]anthracene NLL NLL NLL NLV NLV NLV 20,000 80,000 NA <4.6 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Benzo[a]pyrene NLL NLL NLL NLV NLV NLV 2,000 8,000 NA <4.6 <4.3 <4.8 / <4.8 H 5.6 / <4.3 H <4.7 <11

Benzo[b]fluoranthene NLL NLL NLL ID ID ID 20,000 80,000 NA 4.8 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Benzo[g,h,i]perylene NLL NLL NLL NLV NLV NLV 2,500,000 7,000,000 NA <4.6 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Benzo[k]fluoranthene NLL NLL NLL NLV NLV NLV 200,000 800,000 NA <4.6 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Chrysene NLL NLL NLL ID ID ID 2,000,000 8,000,000 NA <4.6 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Dibenz[a,h]anthracene NLL NLL NLL NLV NLV NLV 2,000 8,000 NA <4.6 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Fluoranthene 730,000 730,000 5,500 1,000,000,000 740,000,000 890,000,000 46,000,000 130,000,000 NA 20 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Fluorene 390,000 890,000 5,300 580,000,000 130,000,000 150,000,000 27,000,000 87,000,000 NA 470 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Indeno(1,2,3-c,d)pyrene NLL NLL NLL NLV NLV NLV 20,000 80,000 NA <4.6 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Naphthalene 35,000 100,000 730 250,000 300,000 350,000 16,000,000 52,000,000 NA 3,400 [3] 34 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Phenanthrene 56,000 160,000 2,100 2,800,000 160,000 190,000 1,600,000 5,200,000 NA 120 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H <4.7 <11

Pyrene 480,000 480,000 ID 1,000,000,000 650,000,000 780,000,000 29,000,000 84,000,000 NA 32 <4.3 <4.8 / <4.8 H <4.3 / <4.3 H 10 <11

Bold indicates contaminant was detected “NLL” means hazardous substance is not likely to leach.

“NLV” means hazardous substance is not likely to volatilize under most conditions.

"H" means re-run sample extracted outside of holding time due to lab error. Results should be considered estimated. "NM" means not measured.

“ID” means insufficient data. "ug/kg" means micrograms per kilogram

"NA" means not available.

Due to a lab error, the semivolatile organic analyses were re-run for the soil samples from 5/3/22. Both sets of results are listed, with the re-run results used for criteria comparison.

[3]

Groundwater

Surface Water

Protection (GSIP)

Criteria

[9]

Soil Saturation

Concentration

(Csat) Screening

Level

[5]

Residential Infinite

Source Volatile Soil

Inhalation Criteria

(VSIC)

[6]

Nonresidential

Infinite Source

VSIC

[8]

Nonresidential

DCC

[2]

Nonresidential

Drinking Water

Protection (DWP)

Criteria

Bold and gray shading indicates contaminant exceeded the listed criteria.

B2 B3B1[1]

Residential

Drinking Water

Protection (DWP)

Criteria

[7]

Residential

Direct Contact

Criteria

(DCC)

[4]

Residential Soil

Volatilization to

Indoor Air Inhalation

(SVIIC) Criteria

Table 2_Aircraft Mishap Site_ Analytical_Soil Borings.xlsx Page 1 of 4

Aircraft Mishap Site

Delta County, Michigan

Location

Sample ID

Laboratory ID

Sample Depth

Date Collected

Organics-Volatiles (ug/kg)

1,2,4-Trimethylbenzene 2,100 2,100 570 4,300,000 21,000,000 25,000,000 32,000,000 100,000,000 110,000

1,3,5-Trimethylbenzene 1,800 1,800 1,100 2,600,000 16,000,000 19,000,000 32,000,000 100,000,000 94,000

Benzene 100 100 4,000 1,600 13,000 45,000 180,000 840,000 400,000

Ethylbenzene 1,500 1,500 360 87,000 720,000 2,400,000 22,000,000 71,000,000 140,000

Toluene 16,000 16,000 5,400 330,000 2,800,000 3,300,000 50,000,000 160,000,000 250,000

Total Xylenes 5,600 5,600 980 6,300,000 46,000,000 54,000,000 410,000,000 1,000,000,000 150,000

2-Methylnaphthalene 57,000 170,000 4,200 2,700,000 1,500,000 1,800,000 8,100,000 26,000,000 NA

Naphthalene 35,000 100,000 730 250,000 300,000 350,000 16,000,000 52,000,000 NA

Organics- Semivolatiles (ug/kg)

2-Methylnaphthalene 57,000 170,000 4,200 2,700,000 1,500,000 1,800,000 8,100,000 26,000,000 NA

Acenaphthene 300,000 880,000 8,700 190,000,000 81,000,000 97,000,000 41,000,000 130,000,000 NA

Acenaphthylene 5,900 17,000 ID 1,600,000 2,200,000 2,700,000 1,600,000 5,200,000 NA

Anthracene 41,000 41,000 ID 1,000,000,000 1,400,000,000 1,600,000,000 230,000,000 730,000,000 NA

Benz[a]anthracene NLL NLL NLL NLV NLV NLV 20,000 80,000 NA

Benzo[a]pyrene NLL NLL NLL NLV NLV NLV 2,000 8,000 NA

Benzo[b]fluoranthene NLL NLL NLL ID ID ID 20,000 80,000 NA

Benzo[g,h,i]perylene NLL NLL NLL NLV NLV NLV 2,500,000 7,000,000 NA

Benzo[k]fluoranthene NLL NLL NLL NLV NLV NLV 200,000 800,000 NA

Chrysene NLL NLL NLL ID ID ID 2,000,000 8,000,000 NA

Dibenz[a,h]anthracene NLL NLL NLL NLV NLV NLV 2,000 8,000 NA

Fluoranthene 730,000 730,000 5,500 1,000,000,000 740,000,000 890,000,000 46,000,000 130,000,000 NA

Fluorene 390,000 890,000 5,300 580,000,000 130,000,000 150,000,000 27,000,000 87,000,000 NA

Indeno(1,2,3-c,d)pyrene NLL NLL NLL NLV NLV NLV 20,000 80,000 NA

Naphthalene 35,000 100,000 730 250,000 300,000 350,000 16,000,000 52,000,000 NA

Phenanthrene 56,000 160,000 2,100 2,800,000 160,000 190,000 1,600,000 5,200,000 NA

Pyrene 480,000 480,000 ID 1,000,000,000 650,000,000 780,000,000 29,000,000 84,000,000 NA

Bold indicates contaminant was detected “NLL” means hazardous substance is not likely to leach.

“NLV” means hazardous substance is not likely to volatilize under most conditions.

"H" means re-run sample extracted outside of holding time due to lab error. Results should be considered estimated. "NM" means not measured.

“ID” means insufficient data. "ug/kg" means micrograms per kilogram

"NA" means not available.

Due to a lab error, the semivolatile organic analyses were re-run for the soil samples from 5/3/22. Both sets of results are listed, with the re-run results used for criteria comparison.

[3]

Groundwater

Surface Water

Protection (GSIP)

Criteria

[9]

Soil Saturation

Concentration

(Csat) Screening

Level

[5]

Residential Infinite

Source Volatile Soil

Inhalation Criteria

(VSIC)

[6]

Nonresidential

Infinite Source

VSIC

[8]

Nonresidential

DCC

[2]

Nonresidential

Drinking Water

Protection (DWP)

Criteria

Bold and gray shading indicates contaminant exceeded the listed criteria.

[1]

Residential

Drinking Water

Protection (DWP)

Criteria

[7]

Residential

Direct Contact

Criteria

(DCC)

[4]

Residential Soil

Volatilization to

Indoor Air Inhalation

(SVIIC) Criteria

AM-B4-4-6-050222 AM-B4-12-14-050222 AM-B5-6-8-050322 AM-B5-6-8-050322-DUP AM-B5-12-14-050322

22050583-03 22050583-04 22050582-08 22050582-09 22050582-10

4 - 6 ft 12 - 14 ft 6 - 8 ft 6 - 8 ft 12 - 14 ft

5/2/2022 5/2/2022 5/3/2022 5/3/2022 5/3/2022

22,000 [1,2,3] 600 [3] 58 <36 <31

8,600 [1,2,3] 190 <110 <120 <100

<370 <41 <34 <36 <31

<370 110 <34 <36 <31

<370 250 <34 <36 <31

11,000 [1,2,3] 720 <100 <110 <94

NA NA <110 <120 <100

NA NA <110 <120 <100

8,700 [3] 570 390 / 11,000 H [3] 1,400 / 960 H <4.3 / <4.3 H

39 <12 <10 / 160 H 14 / <14 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H 11 / <14 H <4.3 / <4.3 H

16 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

6.0 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

6.0 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

28 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

350 23 12 / 510 H 46 / 30 H <4.3 / <4.3 H

<4.7 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

1,400 [3] 42 74 / 1,700 H [3] 340 / 150 H <4.3 / <4.3 H

150 <12 <10 / 71 H <10 / <14 H <4.3 / <4.3 H

44 <12 <10 / <14 H <10 / <14 H <4.3 / <4.3 H

B5B4

Table 2_Aircraft Mishap Site_ Analytical_Soil Borings.xlsx Page 2 of 4

Aircraft Mishap Site

Delta County, Michigan

Location

Sample ID

Laboratory ID

Sample Depth

Date Collected

Organics-Volatiles (ug/kg)

1,2,4-Trimethylbenzene 2,100 2,100 570 4,300,000 21,000,000 25,000,000 32,000,000 100,000,000 110,000

1,3,5-Trimethylbenzene 1,800 1,800 1,100 2,600,000 16,000,000 19,000,000 32,000,000 100,000,000 94,000

Benzene 100 100 4,000 1,600 13,000 45,000 180,000 840,000 400,000

Ethylbenzene 1,500 1,500 360 87,000 720,000 2,400,000 22,000,000 71,000,000 140,000

Toluene 16,000 16,000 5,400 330,000 2,800,000 3,300,000 50,000,000 160,000,000 250,000

Total Xylenes 5,600 5,600 980 6,300,000 46,000,000 54,000,000 410,000,000 1,000,000,000 150,000

2-Methylnaphthalene 57,000 170,000 4,200 2,700,000 1,500,000 1,800,000 8,100,000 26,000,000 NA

Naphthalene 35,000 100,000 730 250,000 300,000 350,000 16,000,000 52,000,000 NA

Organics- Semivolatiles (ug/kg)

2-Methylnaphthalene 57,000 170,000 4,200 2,700,000 1,500,000 1,800,000 8,100,000 26,000,000 NA

Acenaphthene 300,000 880,000 8,700 190,000,000 81,000,000 97,000,000 41,000,000 130,000,000 NA

Acenaphthylene 5,900 17,000 ID 1,600,000 2,200,000 2,700,000 1,600,000 5,200,000 NA

Anthracene 41,000 41,000 ID 1,000,000,000 1,400,000,000 1,600,000,000 230,000,000 730,000,000 NA

Benz[a]anthracene NLL NLL NLL NLV NLV NLV 20,000 80,000 NA

Benzo[a]pyrene NLL NLL NLL NLV NLV NLV 2,000 8,000 NA

Benzo[b]fluoranthene NLL NLL NLL ID ID ID 20,000 80,000 NA

Benzo[g,h,i]perylene NLL NLL NLL NLV NLV NLV 2,500,000 7,000,000 NA

Benzo[k]fluoranthene NLL NLL NLL NLV NLV NLV 200,000 800,000 NA

Chrysene NLL NLL NLL ID ID ID 2,000,000 8,000,000 NA

Dibenz[a,h]anthracene NLL NLL NLL NLV NLV NLV 2,000 8,000 NA

Fluoranthene 730,000 730,000 5,500 1,000,000,000 740,000,000 890,000,000 46,000,000 130,000,000 NA

Fluorene 390,000 890,000 5,300 580,000,000 130,000,000 150,000,000 27,000,000 87,000,000 NA

Indeno(1,2,3-c,d)pyrene NLL NLL NLL NLV NLV NLV 20,000 80,000 NA

Naphthalene 35,000 100,000 730 250,000 300,000 350,000 16,000,000 52,000,000 NA

Phenanthrene 56,000 160,000 2,100 2,800,000 160,000 190,000 1,600,000 5,200,000 NA

Pyrene 480,000 480,000 ID 1,000,000,000 650,000,000 780,000,000 29,000,000 84,000,000 NA

Bold indicates contaminant was detected “NLL” means hazardous substance is not likely to leach.

“NLV” means hazardous substance is not likely to volatilize under most conditions.

"H" means re-run sample extracted outside of holding time due to lab error. Results should be considered estimated. "NM" means not measured.

“ID” means insufficient data. "ug/kg" means micrograms per kilogram

"NA" means not available.

Due to a lab error, the semivolatile organic analyses were re-run for the soil samples from 5/3/22. Both sets of results are listed, with the re-run results used for criteria comparison.

[3]

Groundwater

Surface Water

Protection (GSIP)

Criteria

[9]

Soil Saturation

Concentration

(Csat) Screening

Level

[5]

Residential Infinite

Source Volatile Soil

Inhalation Criteria

(VSIC)

[6]

Nonresidential

Infinite Source

VSIC

[8]

Nonresidential

DCC

[2]

Nonresidential

Drinking Water

Protection (DWP)

Criteria

Bold and gray shading indicates contaminant exceeded the listed criteria.

[1]

Residential

Drinking Water

Protection (DWP)

Criteria

[7]

Residential

Direct Contact

Criteria

(DCC)

[4]

Residential Soil

Volatilization to

Indoor Air Inhalation

(SVIIC) Criteria

AM-B6-8-10-050322 AM-B6-8-10-050322-DUP AM-B6-13-15-050322 AM-B7-2-4-050222 AM-B7-9-11-050222 AM-B8-2-4-050222 AM-B8-15-17-050222

22050582-03 22050582-04 22050582-05 22050583-07 22050583-08 22050583-09 22050583-10

8 - 10 ft 8 - 10…