DERR-2024-010961

2410 WEST CALIFORNIA AVENUE •SALT LAKE CITY, UTAH 84104
PHONE [phone]
Website: www.wasatch-environmental.com • e-Mail: [e-mail]

Ms. Hillary Mason September 20, 2024
Department of Environmental Quality Project No. 1910-002
Division of Environmental Response and Remediation
P.O. Box 144840
Salt Lake City, Utah 84114-4840

RE: Groundwater Monitoring Report
Former Million Air Hangar
303 North 2370 West
Salt Lake City, Utah
UST Facility No: 4002126
Release Site: EJRE

Ms. Mason,

On behalf of our client, Signature Flight Support, Wasatch Environmental, Inc., is submitting the attached
Groundwater Monitoring Report for the former Million Air Hangar site referenced above.

Please feel free to contact us with any questions, comments, or concerns you may have regarding this
report.

Best regards,

Anna Fiorini Blake Downey, P.G.
Environmental Scientist Senior Project Hydrogeologist
Certified UST Consultant: CC0268

2410 WEST CALIFORNIA AVENUE • SALT LAKE CITY, UTAH 84104
PHONE [phone]
Website: www.wasatch-environmental.com • e-Mail: [e-mail]

Ms. Heather Frost September 20, 2024
Signature Flight Support Project No. 1910-002
303 North 2370 West
Salt Lake City, Utah 84116

SUBJECT: Groundwater Monitoring Report
Former Million Air Hangar
303 North 2370 West
Salt Lake City, Utah
UST Facility No: 4002126
Release Site: EJRE

INTRODUCTION

Wasatch Environmental, Inc., (Wasatch) has prepared the groundwater monitoring report for Facility I.D.
No. 4002126, Release Site EJRE (Site). The monitoring wells were sampled on March 14, 2024.

BACKGROUND

It is our understanding that during construction of the former Million Air hangar, two 18,000-gallon
underground storage tanks (USTs) were encountered on the Site. The USTs had been closed in place by
a previous property owner. During removal of the USTs in 1996, petroleum hydrocarbon impacted soil
and groundwater were identified in the UST excavation. A total of 603 tons of impacted soil and 20,000
gallons of impacted groundwater were removed from the UST excavation and disposed off-site.
Petroleum-impacted soil on the east side of the excavation was left in place due to the proximity to
several utility lines.

The concentrations of residual total petroleum hydrocarbon as gasoline-range organics (TPH-GRO) and
benzene detected in soil and groundwater samples collected from the east side of the UST excavation
were above both Utah Initial Screening Levels (ISLs) and Risk-Based Corrective Action Tier 1 Screening
Levels. The release was reported to the Utah Division of Environmental Response and Remediation
(DERR), followed by a request for regulatory closure of the release. In 1998, Million Air received a letter
from the Utah DERR requesting additional investigation to evaluate the extent of impacted soil and
groundwater around the UST excavation. In 2001, two borings were advanced in the hangar
downgradient of the UST excavation. Free product was observed in both borings and work was halted.

In June 2008, a subsurface investigation was performed at the Site, which included advancing eight soil
borings. Soil and groundwater samples were collected from the borings and analyzed for petroleum
hydrocarbon constituents. Based on the laboratory results of the additional sampling, seven groundwater
monitoring wells were installed near the Million Air hangar. Analytical results from groundwater samples
collected in April 2009 and three groundwater monitoring events in 2010 indicated that TPH-GRO and
benzene remained above Utah ISLs. Free product has historically been present in monitoring well MW-5
located inside the hangar. No free product removal has been conducted.

Groundwater monitoring resumed in April 2011. Periodic sampling events have occurred since then.
Monitoring activities for each sampling event included the collection of groundwater elevation data,
checks for free product, and the collection of groundwater samples from monitoring wells MW-1 through
MW-7 for laboratory analysis of petroleum hydrocarbon constituents. Groundwater concentrations have
been compared to Utah ISLs because contamination is located within 30 feet of the Utah DERR defined

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receptors and points of exposure. Each event included a monitoring report that was submitted to the
Utah DERR.

Pursuant to the request from TAC Air to begin a risk-based closure of the Site, the Utah DERR required
that additional groundwater monitoring wells be installed to fully define the impacts to groundwater at the
Site, and to verify that the plume is stable or shrinking. Additionally, the Utah DERR required soil
sampling to be conducted during the installation of the new wells.

In June 2015, four new groundwater monitoring wells were properly installed, developed, and sampled.
No significant soil impacts were discovered during the monitoring well installation activities. Several
groundwater monitoring events have occurred for these wells since that time.

In the March 2018 Groundwater Monitoring Report, Wasatch documented that monitoring wells MW-1
and MW-11 had been destroyed due to Salt Lake City International Airport activities near the wells. The
well vaults had been removed and the wells paved over with asphalt. An attempt was made to locate the
wells, but the wells were not found at that time. Because these wells were believed to be destroyed,
Wasatch requested that these wells and monitoring wells MW-7, MW-8, MW-9, and MW-10 be removed
from the monitoring program. The Utah DERR approved the request to remove these wells; however, the
Utah DERR did express a desire that if monitoring wells MW-1 and MW-11 were found that they should
continue to be monitored as they are the sentinel wells for the plume.

Monitoring wells MW-1 and MW-11 were located by Salt Lake City International Airport personnel in July
2018. New well surface completions were installed by the airport to protect the wells. Therefore, these
wells have been included in groundwater monitoring events since that time.

At our client’s request, Wasatch requested that the Utah DERR approve the Site to move to groundwater
sampling events once every 18 months. Mr. Hillary Mason with the Utah DERR approved this request in
December 2022.

METHODOLOGY

Groundwater Sampling Methodology

On March 14, 2024, groundwater monitoring activities were completed and included collecting
groundwater elevation data and checking for free product in monitoring wells MW-1 through MW-11.
Groundwater samples were collected for laboratory analysis from monitoring wells MW-1 through MW-6
and from MW-11. All monitoring well locations are shown on Figure 1.

Groundwater monitoring was conducted using low-flow sampling techniques following United States
Environmental Protection Agency (U.S. EPA) guidelines, using a peristaltic pump and a multi-parameter
AquaTroll 500 meter to allow for the collection of additional geochemical data including temperature,
specific conductivity, pH, oxidation-reduction potential (ORP), dissolved oxygen (DO), and turbidity.

The sampling procedure involved inserting ¼-inch (outside diameter), low density polyethylene (LDPE)
tubing into each monitoring well. The tubing was run through a peristaltic pump, then to a flow cell to
which a multi-parameter, AquaTroll 500 meter was attached, and finally to a 5-gallon bucket to collect the
purge water. Initial water levels were measured and recorded prior to the initiation of pumping. Once
pumping was initiated, water levels, pumping rate, cumulative volume purged, water temperature, specific
conductivity, pH, ORP, DO, and turbidity were recorded at five-minute intervals until stabilization was
achieved. Pumping rates were maintained at a rate of 90 milliliters per minute to minimize drawdown.
Stabilization was defined as three consecutive measurement intervals where temperature and specific
conductivity were +/- 3%, pH was +/- 0.1, DO was +/-10% (or less than 0.5 milligrams per liter [mg/L]),
and turbidity was +/- 10% (or less than 5 nephelometric turbidity units [NTUs]). After stabilization was
achieved, the tubing was disconnected from the flow cell and the groundwater samples were dispensed
into 40-milliliter capacity, glass vials with Teflon® septa caps. The vials, which were supplied by the
analytical laboratory, contained several drops of hydrochloric acid as a preservative. The vials were filled
slowly until a meniscus formed at the top of each vial, then each vial was sealed with a septa cap. This

Wasatch Environmental Inc.
Page 3
procedure eliminates headspace within the vials and minimizes the loss of volatiles. The sample vials
were each labeled with the analysis required, sampler’s name, sample identification, sample location,
date, and time of sample collection. The samples were placed in a cooler with ice and transported under
chain-of-custody protocol to Chemtech-Ford Laboratories for analysis. Groundwater samples were
analyzed for benzene, toluene, ethylbenzene, xylenes, naphthalene (BTEXN) and TPH-GRO using U.S.
EPA Method 8260D. All groundwater sampling supplies were disposable; therefore, decontamination of
sampling equipment was not required. See Appendix A for a copy of the groundwater sampling forms.

Groundwater Field Measurement Methodology

Depth to groundwater was measured using a dual interface probe. The probe was decontaminated
between each monitoring well using non-phosphate soap, rinsed with distilled water, followed by a
second rinse with distilled water.

RESULTS

Groundwater Results

The laboratory analytical report from the March 14, 2024, groundwater monitoring event is presented in
Appendix B. See Table 1 for the current and historical groundwater analytical results. See Figure 2 for
the TPH-GRO concentrations in groundwater map and Figure 3 for the benzene concentrations in
groundwater map.

TPH-GRO was detected at concentrations exceeding the Utah ISL for TPH-GRO of 1 mg/L in monitoring
wells MW-3 (1.46 mg/L), MW-5 (1.76 mg/L), and MW-6 (1.39 mg/L). TPH-GRO was detected below the
Utah ISL in monitoring well MW-2 at a concentration of 0.947 mg/L, and was not detected in monitoring
wells MW-1, MW-4, and MW-11.

Benzene was detected at concentrations exceeding the Utah ISL for benzene of 0.005 mg/L in monitoring
wells MW-2 (0.064 mg/L), MW-3 (0.212 mg/L), MW-5 (0.110 mg/L), and MW-6 (0.112 mg/L). Benzene
was not detected in monitoring wells MW-1, MW-4, and MW-11.

Ethylbenzene was detected at a trace concentration in monitoring well MW-3 (0.015 mg/L). This
concentration is well below the applicable Utah ISL for ethylbenzene of 0.7 mg/L. Ethylbenzene was not
detected in monitoring wells MW-1, MW-2, MW-4, MW-5, MW-6, and MW-11.

Xylenes were detected at trace concentrations in monitoring wells MW-3 (0.026 mg/L) and MW-5 (0.012
mg/L). These concentrations are well below the applicable Utah ISL for xylenes of 10 mg/L. Xylenes
were not detected in monitoring wells MW-1, MW-2, MW-4, MW-6, and MW-11.

Toluene and naphthalene were not detected in any of the monitoring wells.

No other petroleum hydrocarbon constituents were detected in any of the groundwater samples.

Groundwater Field Measurement Results

Depth to groundwater measurements (see Table 1) were used to construct the potentiometric surface
map presented as Figure 1. The potentiometric surface map indicates that the hydraulic gradient is
generally to the east/northeast at 0.021 feet per foot (based on groundwater elevation data from MW-2,
MW-8, and MW-9). Groundwater elevations increased in most monitoring wells. The average
groundwater elevation increase across the Site since the last sampling event is 1.00 foot. No free
product or sheens were observed in the purge water from any of the monitoring wells. Monitoring wells
MW-3, MW-4, MW-5, and MW-6 had a slight petroleum odor.

Wasatch Environmental Inc.
Page 4
SUMMARY AND CONCLUSIONS

Based on the groundwater elevation data collected, the groundwater flow direction is to the east/northeast
at 0.021 feet per foot.

No free product or sheens were observed in the purge water from any of the monitoring wells. Wasatch
noted that the absorbent sock located in monitoring well MW-5 was approximately 70% saturated and
was replaced upon completion of the sampling activities at this well.

Monitoring wells MW-2, MW-3, MW-5, and MW-6 exhibited TPH-GRO and/or benzene concentrations in
excess of their respective Utah ISLs. TPH-GRO and benzene concentrations generally appear to be
stable to decreasing across the Site since 2015.

The Utah DERR previously requested that Wasatch provide a map that included the historical
environmental sampling conducted by Kleinfelder. This map is presented as Figure 4.

The next groundwater monitoring event is scheduled for September 2025 and will include the following
groundwater monitoring wells: MW-1, MW-2, MW-3, MW-4, MW-5, MW-6, and MW-11.

Our services consist of professional opinions and recommendations made in accordance with generally
accepted environmental engineering principles and practices. This warranty is in lieu of all other
warranties either expressed or implied.

Should you have any questions, please do not hesitate to contact us.

Sincerely,

WASATCH ENVIRONMENTAL, INC.

Anna Fiorini Blake Downey, P.G.
Environmental Scientist Senior Project Hydrogeologist
Certified UST Consultant: CC0268

Table
Table 1: Historical Groundwater Data

Figures
Figure 1: March 2024 Potentiometric Surface Map
Figure 2: March 2024 TPH-GRO Concentrations in Groundwater
Figure 3: March 2024 Benzene Concentrations in Groundwater
Figure 4: Historical Sample Location Map

Appendices
Appendix A: Groundwater Sampling Forms
Appendix B: Analytical Report

Table

Sample
Identity Date
Top of Casing
Elevation
(feet)
Depth to
Groundwater
(feet bgs)
Groundwater
Elevation
(feet)
Product
Thickness
(inches)
TPH
GRO
C6-C10
TPH
DRO
C10-C28
Benzene Toluene Ethylbenzene Xylenes Naphthalene
Methyl
Tertiary-Butyl
Ether
(MTBE)
9/22/08 4.37 94.99 NP 2.6 <1.0 <0.0010 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
4/23/09 3.81 95.55 NP 0.27 <0.52 <0.0010 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
4/2/10 5.50 93.86 NP <0.05 <1 0.002 0.003 <0.001 <0.003 <0.0020 <0.001
7/23/10 4.74 94.62 NP 0.05 <1 <0.001 <0.001 <0.001 <0.003 <0.0020 <0.001
10/27/10 4.68 94.68 NP <0.05 <1 <0.001 <0.001 <0.001 <0.003 <0.0020 <0.001
4/20/11 5.20 94.16 NP <0.02 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/15/11 5.22 94.14 NP <0.50 NA <0.0010 <0.0050 <0.0020 <0.0030 <0.0050 <0.0010
2/2/12 3.73 95.63 NP <0.50 NA <0.0010 <0.0050 <0.0010 <0.0030 <0.0050 <0.0010
9/11/12 3.96 95.40 NP 0.0680 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
12/10/12 3.97 95.39 NP 0.0957 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
3/8/13 3.61 95.75 NP 0.0403 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
6/17/13 3.59 95.77 NP 0.0594 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/13 3.83 95.53 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/11/14 3.71 95.65 NP 0.0695 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/3/14 5.70 93.66 NP 0.020 NA <0.00030 <0.00030 <0.00030 <0.00060 <0.00030 NA
3/6/15 5.25 94.11 NP 0.0941 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
6/23/15 3.71 4219.06 NP ------------------------
9/3/15 3.69 4219.08 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
12/30/15 4.61 4218.16 NP ------------------------
3/2/16 3.76 4219.01 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/16 4.09 4218.68 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 3.32 4219.45 NP 0.0433 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/17 3.91 4218.86 NP 0.0534 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/1/18
9/11/18 3.89 4218.88 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/6/19 3.59 4219.18 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/10/19 4.66 4218.11 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/10/20 3.56 4219.21 NP 0.0349 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/17/20 3.78 4218.99 NP 0.0385 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/2/21 3.76 4219.01 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/21 3.71 4219.06 NP 0.0357 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/15/22 3.54 4219.23 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 NA
9/13/22 3.98 4218.79 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 <0.005
3/14/24 3.23 4219.54 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 NA
9/22/08 3.73 95.78 NP 7.2 0.55 0.22 0.0023 0.0078 0.015 <0.0020 <0.0020
4/23/09 3.17 96.34 NP 3.7 <0.51 0.28 <0.0020 0.0057 0.0066 <0.0020 <0.0020
4/2/10 2.94 96.57 NP 1.6 <1 0.29 0.004 0.004 0.006 0.002 <0.001
7/23/10 3.30 96.21 NP 3.0 <1 0.227 0.001 0.005 0.008 0.002 <0.001
10/27/10 3.43 96.08 NP 2.08 <1 0.26 <0.005 0.007 <0.015 0.005 <0.005
4/20/11 3.18 96.33 NP 23.8 NA 0.136 <0.00200 <0.00200 0.00377 <0.0020 <0.0020
9/15/11 3.66 95.85 Sheen 5.4 NA 0.20 <0.0050 0.0058 0.00940 <0.0050 <0.0020
2/2/12 3.35 96.16 NP 6.5 NA 0.25 <0.025 0.0082 <0.015 <0.025 <0.0050
9/11/12 3.64 95.87 Sheen 3.81 NA 0.220 <0.00200 0.00286 0.00711 0.00612 <0.00200
12/10/12 3.24 96.27 NP 5.48 NA 0.214 <0.00200 0.00473 0.00734 0.00610 <0.00200
3/8/13 3.35 96.16 Sheen 7.72 NA 0.232 <0.00200 0.00334 0.00631 0.00284 NA
6/17/13 3.28 96.23 NP 1.76 NA 0.253 <0.00200 0.00265 0.00468 0.00431 NA
9/5/13 3.67 95.84 NP 3.17 NA 0.233 <0.00200 <0.00200 <0.00200 0.00715 NA
3/11/14 3.19 96.32 NP 4.98 NA 0.271 <0.00200 0.00253 0.00420 0.00358 NA
9/3/14 3.32 96.19 NP 5.300 NA 0.230 <0.0015 0.0019 0.0021 0.0043 NA
3/6/15 3.41 96.10 NP 6.52 NA 0.238 <0.00200 0.00390 0.00501 0.00399 NA
6/23/15 3.21 4219.95 NP ------------------------
9/3/15 3.39 4219.77 NP 3.46 NA 0.257 <0.00200 0.00778 0.00414 0.00491 NA
12/30/15 3.35 4219.81 NP ------------------------
3/2/16 3.52 4219.64 NP 5.80 NA 0.231 <0.00200 0.00636 0.00547 0.00344 NA
9/1/16 3.88 4219.28 NP 4.38 NA 0.217 <0.00200 0.00521 0.00231 0.00345 NA
3/8/17 3.19 4219.97 NP 1.99 NA 0.160 <0.00200 0.00914 0.00599 0.00361 NA
9/5/17 3.85 4219.31 NP 6.83 NA 0.236 <0.00200 0.00599 0.00374 0.00469 NA
3/1/18 3.36 4219.80 NP 6.46 NA 0.193 <0.00200 0.00573 0.00387 0.00294 NA
9/11/18 3.95 4219.21 NP 4.52 NA 0.223 <0.00200 0.00913 0.00338 0.00420 NA
3/6/19 3.61 4219.55 NP 1.90 NA 0.185 <0.00200 0.00886 0.00408 0.00317 NA
9/10/19 3.68 4219.48 NP 3.56 NA 0.139 <0.00200 0.00386 <0.00200 0.00221 NA
3/10/20 3.40 4219.76 NP 5.44 NA 0.189 <0.00200 0.00928 0.00212 0.00417 NA
9/17/20 4.08 4219.08 NP 3.80 NA 0.146 <0.00200 0.00679 0.00342 0.00395 NA
3/2/21 3.51 4219.65 NP 5.03 NA 0.171 <0.00200 0.00894 0.00385 0.00331 NA
9/1/21 3.60 4219.56 NP 4.80 NA 0.149 <0.00200 0.00627 <0.00200 0.00463 NA
3/15/22 3.52 4219.64 NP 3.14 NA 0.118 <0.012 <0.012 <0.012 <0.012 NA
9/13/22 3.90 4219.26 NP 3.16 NA 0.129 <0.012 <0.012 <0.012 <0.012 <0.005
3/14/24 3.31 4219.85 NP 0.947 NA 0.064 <0.012 <0.012 <0.012 <0.012 NA
9/22/08 4.13 95.35 NP 50 <0.50 0.069 0.12 0.018 0.03 <0.0020 <0.0020
4/23/09 3.29 96.19 NP 9.2 <0.51 0.19 0.24 0.013 0.04 <0.0020 <0.0020
4/2/10 3.56 95.92 Sheen 3.58 <1 NA 0.031 0.003 0.025 <0.0020 <0.001
7/23/10 3.62 95.86 Sheen 3.58 <1 0.052 0.031 0.003 0.025 <0.0020 <0.001
10/27/10 3.95 95.53 NP 3.28 <1 0.125 0.028 0.006 0.032 <0.010 <0.005
4/20/11 3.18 96.30 Sheen 78.7 NA 0.0853 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/15/11 4.00 95.48 Sheen 15 NA 0.17 <0.10 <0.020 <0.060 <0.10 <0.020
2/2/12 3.91 95.57 Sheen 17 NA 0.15 <0.025 0.0081 0.032 <0.025 <0.0050
9/11/12 4.08 95.40 Sheen 4.91 NA 0.121 0.00229 0.00879 0.0250 0.00606 <0.00200
12/10/12 3.84 95.64 Sheen 8.37 NA 0.137 0.00618 0.0104 0.0341 0.00638 <0.00200
3/8/13 3.5 95.98 Sheen 7.13 NA 0.121 0.00321 0.00800 0.0241 <0.00200 NA
6/17/13 3.52 95.96 Sheen 5.11 NA 0.141 <0.0200 <0.0200 0.0207 <0.0200 NA
9/5/13 4.07 95.41 NP 6.24 NA 0.123 <0.0200 <0.0200 0.0250 <0.0200 NA
3/11/14 3.59 95.89 Sheen 7.32 NA 0.129 <0.0200 0.00840 0.0160 <0.0200 NA
9/3/14 3.71 95.77 Sheen 6.700 NA 0.140 <0.0015 0.010 0.0266 0.0032 NA
3/6/15 3.90 95.58 Droplets 9.55 NA 0.169 <0.00200 0.0116 0.0301 0.00404 NA
6/23/15 3.55 4219.30 NP ------------------------
9/3/15 3.81 4219.04 sheen 4.90 NA 0.102 <0.00200 <0.00200 0.0250 0.00222 NA
12/30/15 3.88 4218.97 NP ------------------------
3/2/16 3.77 4219.08 NP 4.13 NA 0.174 0.00384 0.0118 0.0294 0.00415 NA
9/1/16 4.22 4218.63 NP 3.90 NA 0.100 <0.00200 0.00383 0.0196 0.00283 NA
3/8/17 3.35 4219.50 NP 1.94 NA 0.0829 0.00248 0.00718 0.0240 0.00258 NA
9/5/17 4.12 4218.73 NP 7.26 NA 0.1060 <0.00200 0.0088 0.0242 0.00281 NA
3/1/18 3.98 4218.87 NP 5.65 NA 0.180 <0.00200 0.0155 0.0319 0.00561 NA
9/11/18 4.20 4218.65 NP 5.19 NA 0.201 <0.00200 0.0177 0.0337 0.00625 NA
3/6/19 3.68 4219.17 NP 1.43 NA 0.123 <0.00200 0.00977 0.0230 0.00314 NA
9/10/19 4.00 4218.85 NP 4.86 NA 0.0878 <0.00200 0.0114 0.0223 0.00294 NA
3/10/20 3.80 4219.05 NP 4.73 NA 0.151 <0.00200 0.0138 0.0261 0.00457 NA
9/17/20 4.32 4218.53 NP 5.27 NA 0.147 <0.00200 0.0142 0.0289 0.00495 NA
3/2/21 3.98 4218.87 NP 3.63 NA 0.135 <0.00200 0.0135 0.0255 0.00407 NA
9/1/21 3.77 4219.08 NP 5.06 NA 0.106 <0.00200 0.0141 0.0272 0.00414 NA
3/15/22 3.83 4219.02 NP 2.87 NA 0.068 <0.012 <0.012 0.017 <0.012 NA
9/13/22 4.10 4218.75 NP 3.29 NA 0.118 <0.012 <0.012 0.019 <0.012 <0.005
3/14/24 NA ------1.46 NA 0.212 <0.012 0.015 0.026 <0.012 NA
4222.85
(All concentrations reported in mg/L)
MW-1
MW-2
MW-3
99.36
99.51
99.48
4222.77
Well Believed to be Destroyed by Salt Lake City Airport Personnel During Repavement Activities
4223.16
Table 1
Historical Groundwater Data
Former Million Air Hanger
304 North 2370 West
Salt Lake City, Utah
Facility ID 4002126, Release Site EJRE
8/21/2024 Page 1 of 4
Sample
Identity Date
Top of Casing
Elevation
(feet)
Depth to
Groundwater
(feet bgs)
Groundwater
Elevation
(feet)
Product
Thickness
(inches)
TPH
GRO
C6-C10
TPH
DRO
C10-C28
Benzene Toluene Ethylbenzene Xylenes Naphthalene
Methyl
Tertiary-Butyl
Ether
(MTBE)
(All concentrations reported in mg/L)
MW-1
99.36
Table 1
Historical Groundwater Data
Former Million Air Hanger
304 North 2370 West
Salt Lake City, Utah
Facility ID 4002126, Release Site EJRE
9/22/08 3.91 96.03 NP 3.7 <0.50 0.0015 <0.0020 0.012 0.0022 <0.0020 <0.0020
4/23/09 2.71 97.23 NP 3.6 <0.63 0.0019 <0.0020 0.014 0.0022 <0.0020 <0.0020
4/2/10 2.61 97.33 NP 1.51 <1 0.003 0.003 0.01 <0.003 <0.0020 <0.001
7/23/10 3.39 96.55 NP 1.84 <1 <0.001 <0.001 0.01 0.005 <0.0020 <0.001
10/27/10 3.69 96.25 NP 1.23 <1 <0.001 <0.001 0.007 <0.003 <0.0020 <0.001
4/20/11 3.41 96.53 NP 7.91 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/15/11 3.68 96.26 NP 2.9 NA 0.0010 <0.0050 0.0096 <0.0030 <0.0050 <0.0010
2/2/12 3.35 96.59 NP 3 NA <0.0010 <0.0050 0.0079 <0.0030 <0.0050 <0.0010
9/11/12 3.83 96.11 NP 2.18 NA <0.00100 <0.00200 0.00484 0.00268 <0.00200 <0.00200
12/10/12 3.10 96.84 NP <0.0200 NA <0.00100 <0.00200 0.00854 <0.00200 <0.00200 <0.00200
3/8/13 3.08 96.86 NP 3.81 NA <0.00100 <0.00200 0.00724 <0.00200 <0.00200 NA
6/17/13 3.01 96.93 NP 2.16 NA <0.00100 <0.00200 0.00749 <0.00200 <0.00200 NA
9/5/13 3.88 96.06 NP 1.88 NA <0.00100 <0.00200 0.00588 <0.00200 <0.00200 NA
3/11/14 3.04 96.90 NP 3.10 NA <0.0100 <0.0200 0.00620 <0.0200 <0.0200 NA
9/3/14 3.28 96.66 Sheen 1.100 NA 0.00061 <0.00030 0.0047 <0.00060 <0.00030 NA
3/6/15 3.45 96.49 NP 3.24 NA <0.00100 <0.00200 0.00383 <0.00200 <0.00200 NA
6/23/15 3.06 4220.46 NP ------------------------
9/3/15 3.48 4220.04 NP 3.93 NA <0.00100 <0.00200 0.01090 <0.00200 <0.00200 NA
12/30/15 3.30 4220.22 NP ------------------------
3/2/16 3.21 4220.31 NP 3.21 NA <0.00100 <0.00200 0.00735 <0.00200 <0.00200 NA
9/1/16 4.03 4219.49 NP 0.230 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 2.42 4221.10 NP 1.22 NA <0.00100 <0.00200 0.00349 <0.00200 <0.00200 NA
9/5/17 3.94 4219.58 NP 6.81 NA <0.00100 <0.00200 0.00853 <0.00200 <0.00200 NA
3/1/18 3.31 4220.21 NP 2.29 NA <0.00100 <0.00200 0.00240 <0.00200 <0.00200 NA
9/11/18 3.98 4219.54 NP 3.91 NA <0.00100 <0.00200 0.00817 <0.00200 <0.00200 NA
3/6/19 2.50 4221.02 NP 0.763 NA <0.00100 <0.00200 0.00389 <0.00200 <0.00200 NA
9/10/19 3.70 4219.82 NP 2.13 NA <0.00100 <0.00200 0.00454 <0.00200 <0.00200 NA
3/10/20 3.03 4220.49 NP 1.28 NA <0.00100 <0.00200 0.00289 <0.00200 <0.00200 NA
9/17/20 4.05 4219.47 NP 5.52 NA <0.00100 <0.00200 0.00679 <0.00200 <0.00200 NA
3/2/21 3.21 4220.31 NP 1.96 NA <0.00100 <0.00200 0.00418 <0.00200 <0.00200 NA
9/1/21 3.17 4220.35 NP 4.77 NA <0.00100 <0.00200 0.00591 <0.00200 <0.00200 NA
3/15/22 2.82 4220.70 NP 2.27 NA 0.072 <0.012 0.012 0.018 <0.012 NA
9/13/22 3.80 4219.72 NP 1.35 NA <0.005 <0.012 <0.012 <0.012 <0.012 <0.005
3/14/24 2.40 4221.12 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 NA
9/22/08 4.21 95.32 Sheen 180 3 0.22 <0.10 <0.10 <0.10 <0.10 <0.10
4/23/09 3.28 96.25 NP 38 0.6 0.32 <0.040 <0.040 0.064 <0.40 <0.40
4/2/10 3.71 95.82 0.36 5.1 <1 0.039 0.003 0.004 0.044 <0.0020 <0.001
7/23/10 3.71 95.82 1.32 ------------------------
10/27/10 4.26 95.27 1.68 ------------------------
4/20/11 3.15 96.38 Sheen 352 NA 0.134 <0.0200 <0.0200 <0.0200 <0.0200 <0.0200
9/15/11 4.03 95.50 0.36 ---NA ------------------
2/2/12 4.00 95.53 Sheen 31 NA 0.18 <0.050 0.018 0.054 <0.050 <0.010
9/11/12 4.11 95.42 Sheen 8.15 NA 0.244 0.00339 0.0105 0.0253 0.00604 <0.00200
12/10/12 3.99 95.54 0.72 ------------------------
3/8/13 3.52 96.01 Sheen 15.8 NA 0.221 <0.00200 0.00992 0.0245 0.00277 NA
6/17/13 3.53 96.00 Sheen 7.20 NA 0.243 <0.0200 <0.0200 <0.0200 <0.0200 NA
9/5/13 4.06 95.47 0.12 11.2 NA 0.205 <0.0200 <0.0200 0.0265 <0.0200 NA
3/11/14 3.58 95.95 Sheen 16.9 NA 0.230 <0.0200 0.0108 0.0145 <0.0200 NA
9/3/14 3.70 95.83 Droplets 13.0 NA 0.200 <0.0015 0.013 0.030 0.0037 NA
3/6/15 4.00 95.53 0.12 14.3 NA 0.237 <0.00200 0.0159 0.0326 0.00440 NA
6/23/15 3.49 4219.40 NP ------------------------
9/3/15 3.79 4219.10 1.08 8.4 NA 0.223 <0.00200 0.0137 0.0377 0.00464 NA
12/30/15 3.91 4218.98 NP ------------------------
3/2/16 3.71 4219.18 NP 6.45 NA 0.261 <0.00200 0.0122 0.0342 0.00456 NA
9/1/16 4.21 4218.68 NP 4.34 NA 0.277 <0.00200 0.0116 0.0250 0.00334 NA
3/8/17 3.46 4219.43 Droplets/Sheen 3.04 NA 0.229 <0.00200 0.0123 0.0410 0.00601 NA
9/5/17 3.49 4219.40 0.6 205 NA 0.14 <0.00200 0.00904 0.0352 0.00513 NA
3/1/18 4.00 4218.89 1.20 7.72 NA 0.240 <0.00200 0.0174 0.0386 0.00514 NA
9/11/18 4.35 4218.54 1.68 7.79 NA 0.240 <0.00200 0.0172 0.0240 0.00431 NA
3/6/19 3.80 4219.09 3.12 2.04 NA 0.236 <0.00200 0.0134 0.0284 0.00432 NA
9/10/19 4.09 4218.80 NP 8.12 NA 0.201 <0.00200 0.0117 0.0262 0.00383 NA
3/10/20 3.79 4219.10 NP 8.41 NA 0.228 <0.00200 0.0115 0.0226 0.00398 NA
9/17/20 4.30 4218.59 NP 7.40 NA 0.226 <0.00200 0.0157 0.0319 0.00530 NA
3/2/21 4.08 4218.81 NP 5.89 NA 0.217 <0.00200 0.0149 0.0241 0.00497 NA
9/1/21 3.82 4219.07 NP 16.4 NA 0.208 <0.00200 0.0168 0.0285 0.00593 NA
3/15/22 4.00 4218.89 NP 5.41 NA 0.163 <0.012 0.014 0.022 <0.012 NA
9/13/22 4.18 4218.71 NP 4.64 NA 0.177 <0.012 0.013 0.018 <0.012 <0.005
3/14/24 NA ------1.76 NA 0.110 <0.012 <0.012 0.012 <0.012 NA
9/22/08 4.01 95.65 NP 12 <0.50 0.11 <0.0020 0.011 0.004 0.0021 <0.0020
4/23/09 2.94 96.72 NP 7.1 <0.51 0.25 <0.0020 0.014 0.0028 0.0056 <0.0020
4/2/10 3.28 96.38 NP 2.8 <1 0.206 0.003 0.01 <0.003 0.006 <0.001
7/23/10 3.43 96.23 NP 3.48 <1 0.197 <0.001 0.009 0.005 0.008 <0.001
10/27/10 3.93 95.73 NP 1.77 <1 0.155 <0.001 0.009 <0.003 0.006 <0.001
4/20/11 2.88 96.78 NP 19.4 NA <0.0020 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/15/11 3.81 95.85 Sheen 5.1 NA 0.18 <0.0030 0.0051 <0.0030 0.0062 <0.0010
2/2/12 3.26 96.40 NP 6.2 NA 0.16 <0.0050 0.0061 <0.0030 0.0054 <0.0010
9/11/12 3.84 95.82 NP 4.96 NA 0.190 <0.00200 0.00594 0.00419 0.00903 <0.00200
12/10/12 3.60 96.06 Sheen 5.93 NA 0.174 <0.00200 0.00689 <0.00200 0.00826 <0.00200
3/8/13 3.11 96.55 Sheen 6.35 NA 0.172 <0.00200 0.00605 <0.00200 0.00675 NA
6/17/13 3.23 96.43 NP 1.94 NA 0.175 <0.00200 0.00641 <0.00200 0.00746 NA
9/5/13 3.82 95.84 NP 3.36 NA 0.152 <0.00200 0.00418 <0.00200 0.00643 NA
3/11/14 3.21 96.45 NP 5.51 NA 0.150 <0.00200 0.00769 <0.00200 0.00612 NA
9/3/14 3.44 96.22 NP 5.200 NA 0.140 <0.00030 0.0049 0.00094 0.0078 NA
3/6/15 3.70 95.96 NP 7.24 NA 0.149 <0.00200 0.00660 <0.00200 0.00839 NA
6/23/15 3.25 4219.88 NP ------------------------
9/3/15 3.57 4219.56 NP 3.42 NA 0.163 <0.00200 <0.00200 <0.00200 0.00796 NA
12/30/15 3.66 4219.47 NP ------------------------
3/2/16 3.48 4219.65 NP 4.92 NA 0.162 <0.00200 0.00239 <0.00200 0.00737 NA
9/1/16 4.01 4219.12 NP 0.330 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 3.11 4220.02 NP 1.65 NA 0.0525 <0.00200 <0.00200 <0.00200 0.00327 NA
9/5/17 3.94 4219.19 NP 4.28 NA 0.075 <0.00200 <0.00200 <0.00200 0.00405 NA
3/1/18 3.72 4219.41 NP 5.35 NA 0.0675 <0.00200 <0.00200 <0.00200 0.00467 NA
9/11/18 4.03 4219.10 NP 4.60 NA 0.0809 <0.00200 <0.00200 <0.00200 0.00627 NA
3/6/19 3.36 4219.77 NP 1.51 NA 0.0641 <0.00200 <0.00200 <0.00200 0.00460 NA
9/10/19 3.79 4219.34 NP 2.89 NA 0.0848 <0.00200 <0.00200 <0.00200 0.00473 NA
3/10/20 3.47 4219.66 NP 5.25 NA 0.109 <0.00200 <0.00200 <0.00200 0.00686 NA
9/17/20 4.12 4219.01 NP 4.91 NA 0.112 <0.00200 <0.00200 <0.00200 0.00757 NA
3/2/21 3.67 4219.46 NP 4.39 NA 0.103 <0.00200 <0.00200 <0.00200 0.00645 NA
9/1/21 3.56 4219.57 NP 5.61 NA 0.110 <0.00200 <0.00200 <0.00200 0.00812 NA
3/15/22 3.68 4219.45 NP 2.75 NA 0.078 <0.012 <0.012 <0.012 <0.012 NA
9/13/22 3.90 4219.23 NP 2.60 NA 0.098 <0.012 <0.012 <0.012 <0.012 <0.005
3/14/24 3.10 4220.03 NP 1.39 NA 0.112 <0.012 <0.012 <0.012 <0.012 NA
MW-4
MW-5
MW-6
99.94
4223.52
4222.89
4223.13
99.66
99.53
8/21/2024 Page 2 of 4
Sample
Identity Date
Top of Casing
Elevation
(feet)
Depth to
Groundwater
(feet bgs)
Groundwater
Elevation
(feet)
Product
Thickness
(inches)
TPH
GRO
C6-C10
TPH
DRO
C10-C28
Benzene Toluene Ethylbenzene Xylenes Naphthalene
Methyl
Tertiary-Butyl
Ether
(MTBE)
(All concentrations reported in mg/L)
MW-1
99.36
Table 1
Historical Groundwater Data
Former Million Air Hanger
304 North 2370 West
Salt Lake City, Utah
Facility ID 4002126, Release Site EJRE
9/22/08 3.35 96.63 NP 9 0.5 0.0081 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
4/23/09 3.05 96.93 Sheen 0.88 <0.51 0.006 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
4/2/10 3.07 96.91 NP 0.229 <1 0.014 0.003 <0.001 <0.003 <0.002 <0.001
7/23/10 3.21 96.77 NP 0.458 <1 0.001 <0.001 <0.001 <0.003 <0.002 <0.001
10/27/10 3.19 96.79 NP 0.538 <1 0.006 0.001 <0.001 <0.003 <0.002 <0.001
4/20/11 2.83 97.15 Sheen 4.66 NA 0.0043 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/15/11 3.27 96.71 Sheen 0.72 NA 0.0012 <0.0050 <0.0010 <0.0030 <0.0050 <0.0010
2/2/12 3.10 96.88 Sheen 0.56 NA 0.0017 <0.0050 <0.0010 <0.0030 <0.0050 <0.0010
9/11/12 3.25 96.73 NP 0.200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
12/10/12 3.16 96.82 NP 0.345 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
3/8/13 2.97 97.01 Sheen 0.0888 NA 0.00276 <0.00200 <0.00200 <0.00200 <0.00200 NA
6/17/13 3.15 96.83 Sheen 0.228 NA 0.00108 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/13 3.35 96.63 Sheen <0.200 NA <0.0100 <0.0200 <0.0200 <0.0200 <0.0200 NA
3/11/14 3.02 96.96 Sheen 0.392 NA 0.00139 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/3/14 3.18 96.80 Sheen 0.170 NA 0.00051 <0.00030 <0.00030 <0.00060 <0.00030 NA
3/6/15 3.08 96.90 Sheen 0.912 NA 0.00371 <0.00200 <0.00200 <0.00200 <0.00200 NA
6/23/15 2.95 4219.50 NP ------------------------
9/3/15 3.11 4219.34 NP 0.105 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
12/30/15 3.08 4219.37 NP ------------------------
3/2/16 2.96 4219.49 NP 0.0299 NA 0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/16 3.53 4218.92 NP 0.0403 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 2.73 4219.72 NP 0.0592 NA 0.00181 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/17 3.54 4218.91 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/1/18 3.11 4219.34 NP 0.0595 NA 0.00127 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/11/18 3.59 4218.86 NP ------------------------
3/6/19 3.03 4219.42 NP ------------------------
9/10/19 3.34 4219.11 NP ------------------------
3/10/20 3.13 4219.32 NP ------------------------
9/17/20 3.66 4218.79 NP ------------------------
3/2/21 3.28 4219.17 NP ------------------------
9/1/21 3.31 4219.14 NP ------------------------
3/15/22 3.11 4219.34 NP ------------------------
9/13/22 3.63 4218.82 NP ------------------------
3/14/24 2.98 4219.47 NP ------------------------
6/23/15 5.31 4216.33 NP 0.611 <0.500 <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 0.00215
9/3/15 5.61 4216.03 NP 0.224 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
12/30/15 5.29 4216.35 NP 0.433 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/2/16 5.29 4216.35 NP 0.375 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/16 5.33 4216.31 NP 0.284 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 5.19 4216.45 NP 0.282 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/17 5.36 4216.28 NP 0.689 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/1/18 5.26 4216.38 NP 0.207 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/11/18 5.4 4216.24 NP ------------------------
3/6/19 5.28 4216.36 NP ------------------------
9/10/19 5.42 4216.22 NP ------------------------
3/10/20 5.34 4216.30 NP ------------------------
9/17/20 5.49 4216.15 NP ------------------------
3/2/21 5.42 4216.22 NP ------------------------
9/1/21 5.44 4216.20 NP ------------------------
3/15/22 5.38 4216.26 NP ------------------------
9/13/22 5.53 4216.11 NP ------------------------
3/14/24 5.27 4216.37 NP ------------------------
6/23/15 1.70 4221.25 NP <0.0200 <0.500 <0.00100 <0.00200 0.006 <0.00200 <0.00200 <0.00200
9/3/15 2.53 4220.42 NP <0.0200 NA <0.00100 <0.00200 0.003 <0.00200 <0.00200 NA
12/30/15 2.90 4220.05 NP 0.240 NA <0.00100 <0.00200 <0.00200 0.011 <0.00200 NA
3/2/16 1.27 4221.68 NP 0.106 NA 0.00164 <0.00200 0.00721 0.0517 <0.00200 NA
9/1/16 2.41 4220.54 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 0.60 4222.35 NP 0.212 NA 0.00242 <0.00200 0.0181 0.0885 <0.00200 NA
9/5/17 3.45 4219.50 NP <0.0200 NA <0.00100 <0.00200 <0.00200 0.0045 <0.00200 NA
3/1/18 1.41 4221.54 NP 0.220 NA 0.00285 0.0111 0.0110 0.0414 <0.00200 NA
9/11/18 3.44 4219.51 NP ------------------------
3/6/19 1.36 4221.59 NP ------------------------
9/10/19 2.31 4220.64 NP ------------------------
3/10/20 1.33 4221.62 NP ------------------------
9/17/21 3.18 4219.77 NP ------------------------
3/2/21 3.01 4219.94 NP ------------------------
9/1/21 2.80 4220.15 NP ------------------------
3/15/22 2.47 4220.48 NP ------------------------
9/13/22 3.34 4219.61 NP ------------------------
3/14/24 1.84 4221.11 NP ------------------------
6/23/15 2.05 4220.47 NP 0.107 <0.500 <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/3/15 2.41 4220.11 NP 0.216 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
12/30/15 2.34 4220.18 NP 0.050 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/2/16 2.23 4220.29 NP 0.0709 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/16 3.04 4219.48 NP 0.110 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 0.98 4221.54 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/17 2.95 4219.57 NP 0.076 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/1/18 2.21 4220.31 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/11/18 2.98 4219.54 NP ------------------------
3/6/19 0.86 4221.66 NP ------------------------
9/10/19 2.71 4219.81 NP ------------------------
3/10/20 1.94 4220.58 NP ------------------------
9/17/20 3.04 4219.48 NP ------------------------
3/2/21 2.25 4220.27 NP ------------------------
9/1/21 2.18 4220.34 NP ------------------------
3/15/22 1.35 4221.17 NP ------------------------
9/13/22 2.80 4219.72 NP ------------------------
3/14/24 0.67 4221.85 NP ------------------------
4222.52
MW-8
MW-9
MW-7
99.98
4221.64
4222.95
MW-10
4222.45
8/21/2024 Page 3 of 4
Sample
Identity Date
Top of Casing
Elevation
(feet)
Depth to
Groundwater
(feet bgs)
Groundwater
Elevation
(feet)
Product
Thickness
(inches)
TPH
GRO
C6-C10
TPH
DRO
C10-C28
Benzene Toluene Ethylbenzene Xylenes Naphthalene
Methyl
Tertiary-Butyl
Ether
(MTBE)
(All concentrations reported in mg/L)
MW-1
99.36
Table 1
Historical Groundwater Data
Former Million Air Hanger
304 North 2370 West
Salt Lake City, Utah
Facility ID 4002126, Release Site EJRE
6/23/15 4.97 4217.69 NP <0.0200 <0.500 <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 <0.00200
9/3/15 5.25 4217.41 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
12/30/15 4.86 4217.80 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/2/16 5.20 4217.46 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/16 5.61 4217.05 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/8/17 3.93 4218.73 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/5/17 5.35 4217.31 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/1/18
9/11/18 5.10 4217.56 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/6/19 4.26 4218.40 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/10/19 5.05 4217.61 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/10/20 4.61 4218.05 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/17/20 5.23 4217.43 NP 0.229 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/2/21 4.66 4218.00 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
9/1/21 4.57 4218.09 NP <0.0200 NA <0.00100 <0.00200 <0.00200 <0.00200 <0.00200 NA
3/15/22 4.32 4218.34 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 NA
9/13/22 4.99 4217.67 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 <0.005
3/14/24 4.05 4218.61 NP <0.125 NA <0.005 <0.012 <0.012 <0.012 <0.012 NA
UTAH INITIAL SCREENING LEVEL ---------1 1 0.005 1 0.7 10 0.7 0.2
TPH-GRO = Total Petroleum Hydrocarbons (Gasoline Range C6 to C10)
TPH-DRO = Total Petroleum Hydrocarbons (Diesel Range C10 to C28)
< = Concentrations less than the given method reporting limits
BOLD = Measured concentration exceeds Utah Initial Screening Level
--- = Not Sampled
NA = Not Analyzed
NP = No Product
Well Believed to be Destroyed by Salt Lake City Airport Personnel During Repavement Activities
MW-11 4222.66
8/21/2024 Page 4 of 4

Figures

&A
&A
&A
&A &A
&A
&A
&A
&A
&A
&A
MW-7
MW-1
MW-5MW-4
MW-3
(4219.54)
(4221.12)
(4219.47)
[[[[[[[[[[[[[[[
(4221.85)
(4220.03)
MW-6
(4221.11)
(4218.61)
(4216.37)
MW-9
MW-10
MW-11
MW-8
Approximate Extent
of UST Excavation
(4219.85)
MW-2
PROJECT NO.
March 2024 Potentiometric
Surface Map
SAMPLING DATE FIGURE
1µ1910-002
!A Monitoring Well Location
Groundwater Elevation Contour
Groundwater Elevation(4220.44)
TAC Air
303 North 2370 West
Salt Lake City, Utah
FACILITY No. 4002126
RELEASE SITE: EJRE
Sinclair
Hanger
GAS
GA
S
WATER
WATE
R
GA
S
G
A
S
POW
E
R
GA
S
FAA
L
I
N
E
FAA
L
I
N
E
FLOOR
DRAIN
0 30 6015 Feet
(Former Million Air Hanger)
TacAir Hanger
March 14, 2024
Hydrau
l
i
c

G
r
a
d
i
e
n
t
0.021 ft
.
/
f
t
.
General

G
r
o
u
n
d
w
a
t
e
r
Flow Di
r
e
c
t
i
o
n
&A
&A
&A
&A &A
&A
&A
&A
&A
&A
&A
MW-7
MW-1
MW-4
MW-2
[[[[[[[[[[[[[[[
MW-6
MW-9
MW-10
MW-11
MW-8
Approximate Extent
of UST Excavation
MW-3
PROJECT NO.SAMPLING DATE FIGURE
2µ1910-002
TacAir Hanger
(Former Million Air Hanger)
!A Monitoring Well Location
TAC Air
303 North 2370 West
Salt Lake City, Utah
FACILITY No. 4002126
RELEASE SITE: EJRE
Sinclair
Hanger
GAS
GA
S
WATER
WATE
R
GA
S
G
A
S
POW
E
R
GA
S
FAA
L
I
N
E
FAA
L
I
N
E
FLOOR
DRAIN
0 30 6015 Feet
(0.947)
Groundwater Concentration Contour (mg/L)
Groundwater TPG-GRO Concentrations (mg/L)(5.5)
March 2024 TPH-GRO
Concentrations in Groundwater
(<0.125)
(1.46)
(Not Sampled)
(Not Sampled)
(Not Sampled)
(<0.125)
(1.39)
(Not Sampled)
MW-5
(1.76)
(<0.125)
March 14, 2024
(0.064)
(0.212)
(0.110)
(0.112)
March 2024 Benzene
MW-5
(<0.005)
(<0.005)
MW-3
MW-6
(<0.005)
Concentrations in Groundwater
March 14, 2024
&A
&A
&A
&A &A
&A
&A
&A
&A
&A
&A
MW-7
MW-1
MW-5/P-4MW-4
MW-2/P-7
MW-3/P-5
[[[[[[[[[[[[[[[
MW-6
MW-9
MW-10
MW-11
MW-8
Approximate Extentof UST Excavation
PROJECT NO.
Historical Sample Location Map
DRAWING DATE FIGURE4µMarch 2, 20161910-002
TacAir Hanger(Former Million Air Hanger)
!A Monitoring Well Location
TAC Air303 North 2370 WestSalt Lake City, Utah
FACILITY No. 4002126RELEASE SITE: EJRE
SinclairHanger
GAS
GAS
WATER
WATER
GAS
GAS
P O W E R
GAS
FAA LINE
FAA LINEFLOORDRAIN
0 30 6015 Feet
P-6
P-1
P-3
P-8
P-2
(P-X) Prior Kleinfelder Soil Boring Location When NotLocated With An Existing Monitoring Well
SS-5
SS-2
SS-1 SS-3
SS-4
WS-2SS-Center
Klienfelder Confirmation Sample Location

Appendix A
Groundwater Sampling Forms

Appendix B
Analytical Report

The analyses presented on this report were performed in accordance with the
National Environmental Laboratory Accreditation Program (NELAP) unless
noted in the comments, flags, or case narrative. If the report is to be used for
regulatory compliance, it should be presented in its entirety, and not be
altered.
Client Service Contact: 801.262.7299
Wasatch Environmental
Attn: Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
Work Order: 24C1059
Project: TAC Air
3/20/2024
Approved By:
Melissa Connolly, Project Manager
9632 South 500 West Sandy, Utah 84070
Serving the Intermountain West since 1953
801.262.7299 Main 866.792.0093 Fax www.ChemtechFord.com
Page 1 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-1
Lab ID: 24C1059-01Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 11:45
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030BNDBenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDEthylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDXylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]NDGasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 2 of 10Page 2 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-2
Lab ID: 24C1059-02Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 11:05
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030B0.064Benzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDEthylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDXylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]0.947Gasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 3 of 10Page 3 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-3
Lab ID: 24C1059-03Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 8:20
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030B0.212Benzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030B0.015Ethylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030B0.026Xylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]1.46Gasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 4 of 10Page 4 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-4
Lab ID: 24C1059-04Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 10:05
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030BNDBenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDEthylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDXylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]NDGasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 5 of 10Page 5 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-5
Lab ID: 24C1059-05Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 7:35
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030B0.110Benzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDEthylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030B0.012Xylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]1.76Gasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 6 of 10Page 6 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-6
Lab ID: 24C1059-06Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 9:15
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030B0.112Benzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDEthylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDXylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]1.39Gasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 7 of 10Page 7 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Sample ID: MW-11
Lab ID: 24C1059-07Matrix: Water
Flag(s)Units
Analysis
Date/Time
Date Sampled: 3/14/24 12:30
Preparation
Date/Time
Sampled By: Anna Fiorini
Minimum
Reporting
Limit MethodResult
MBTEXn
mg/L 3/18/243/18/240.005 EPA 8260D/5030BNDBenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDEthylbenzene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDNaphthalene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDToluene
mg/L 3/18/243/18/240.012 EPA 8260D/5030BNDXylenes, total
Gasoline Range
mg/L 3/18/243/18/240.125 EPA 8260B/C /5030A/[CALC]NDGasoline Range Organics
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 8 of 10Page 8 of 10
xx
Chemtech-Ford Laboratories
Serving the Intermountain West Since 1953
Certificate of Analysis
9632 South 500 West
Sandy, UT 84070
O:[phone] F: [phone]
www.ChemtechFord.com
Wasatch Environmental
Blake Downey
2410 West California Avenue
Salt Lake City, UT 84104
PO#:
Receipt:
Date Reported:
Project Name:
1910-002
3/14/24 15:00 @ 0.9 °C
3/20/2024
TAC Air
Report Footnotes
Abbreviations
ND = Not detected at the corresponding Minimum Reporting Limit (MRL).
1 mg/L = one milligram per liter or 1 mg/kg = one milligram per kilogram = 1 part per million.
1 ug/L = one microgram per liter or 1 ug/kg = one microgram per kilogram = 1 part per billion.
1 ng/L = one nanogram per liter or 1 ng/kg = one nanogram per kilogram = 1 part per trillion.
On calculated parameters, there may be a slight difference between summing the rounded values shown on the report
vs the unrounded values used in the calculation.
Project Name: TAC Air CtF WO#: 24C1059
www.ChemtechFord.com
Page 9 of 10Page 9 of 10
Page 10 of 10