DSHW-2023-207382 - 0901a0688124e2c0

State of Utah Mail - Fwd: Marathon Refinery Truck Loading Rack LNAPL Transmissivity Evaluation Report and Proposed Semi An…
Deq submit <[e-mail]>
Fwd: Marathon Refinery Truck Loading Rack LNAPL Transmissivity Evaluation
Report and Proposed Semi Annual GW Sampling Plan
1 message
Dale Urban <[e-mail]>Thu, Aug 3, 2023 at 12:22 PM
To: Deq submit <[e-mail]>
These are from the Tesoro Refinery
---------- Forwarded message ---------
From: Stuart Beling <[e-mail]>
Date: Wed, Jul 19, 2023 at 6:31 AM
Subject: Marathon Refinery Truck Loading Rack LNAPL Transmissivity Evaluation Report and Proposed Semi Annual GW
Sampling Plan
To: Dale Urban <[e-mail]>
Cc: Hendricks, Peter M. <[e-mail]>
Dale,
Attached for your review are the draft transmissivity evaluation report and the proposed semi annual GW sampling plan
we discussed in our call yesterday.
Stuart J. Beling | Senior Project Manager | USA
Antea®Group
Mobile [phone] | Toll Free 800 477 7411
[e-mail] | us.anteagroup.com
--
Dale T. Urban, P.G.
Environmental Scientist | Corrective Action Section
Division of Waste Management and Radiation Control
DSHW-2023-207382
State of Utah Mail - Fwd: Marathon Refinery Truck Loading Rack LNAPL Transmissivity Evaluation Report and Proposed Semi An…
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2 attachments
Salt Lake Refinery TLR LNAPL Tn Evaluation 2023-07-17.pdf
2468K
TLR Semi Annual GWM Work Plan 2023-07-17.pdf
3249K

Marathon Refinery
Salt Lake City, UT
Truck Loading Rack LNAPL Transmissivity Evaluation 
PREPARED FOR
Marathon Petroleum Company  

PREPARED BY
Antea Group  

July 17, 2023 

Project # K022SLCRF 
Contents
1.0 Purpose .......................................................................................................................................................... 1 
2.0 Overview ........................................................................................................................................................ 1 
3.0 Truck Loading Rack Active Pumping Gauging and Bail Down Testing ............................................................. 2 
4.0 Truck Loading Rack Post Pumping Gauging ................................................................................................... 2 
5.0 Conclusions and Recommendations .............................................................................................................. 3 
6.0 References ..................................................................................................................................................... 4 
Figures
Figure 1 – Site Location Map  
Figure 2 ‐‐ Truck Loading Rack Site Map 
Tables
Table 1 – Well 02A Active Recovery Well Bail Down Gauging Data 
Table 2 – Well 01A Post Recovery Well Shut Down Gauging Data 
Table 3 – Well 02A Post Recovery Well Shut Down Gauging Data 
Charts
Chart 1 – Well 01/01A Historical Groundwater Elevation and LNAPL vs Time 
Chart 2 – Well 02/02A Historical Groundwater Elevation and LNAPL vs Time 
Appendix
Appendix A ‐Historical Well Gauging Data 

1 
Marathon Salt Lake City Refinery
Truck Loading Rack LNAPL Transmissivity Evaluation  
1.0 PURPOSE
Antea®Group on behalf of Tesoro Refining & Marketing Company LLC, a part of Marathon Petroleum Company 
LP (Marathon) has prepared this report summarizing the work performed to evaluate the residual light non‐
aqueous phase liquids (LNAPL) mobility and recoverability at the Truck Loading Rack (TLR). The results of this 
work will be used to satisfy criteria needed to determine if hydraulic controls of groundwater via pumping 
groundwater from recovery well RS‐W1A can be discontinued. The proposed scope of work was submitted to 
the Utah Department of Environmental Quality (DEQ), Division of Waste Management and Radiation Control 
(DWMRC) (the Division) on August 3, 2022, and the Division approved the proposed work and deactivation of 
recovery well RS‐W1A in correspondence dated September 22, 2022. 
2.0 OVERVIEW
Assessment of the dissolved phase and LNAPL in the subsurface at the SLC Refinery has been ongoing since the 
early 1980s. Groundwater pumping for gradient control has been performed, in accordance with the Corrective 
Action Plan (CAP), for over 20 years to address the Division’s concerns for potential off‐site migration of 
dissolved phased petroleum and LNAPL. The ongoing groundwater pumping was intended to contain and to 
prevent potential off‐site migration of dissolved phase and LNAPL and assumed that the potential rate of 
migration would exceed the rate of biodegradation or natural degradation. Forty years later, the extent and 
frequency of measured LNAPL in monitoring wells and piezometers has diminished since the 1980s, suggesting 
degradation has been ongoing.  

In 2020, LNAPL mobility and recoverability assessment work was performed by Marathon on the LNAPL located 
in wells on the main Refinery located to north of the TLR across 900 North Street. The attached Figure 1 shows 
the locations of the main Refinery and TLR. The results of the assessment work indicated the LNAPL 
Transmissivity (Tn) was too low to be accurately measured and therefore below the Interstate Technology 
Regulatory Council (ITRC) recoverability threshold metric range of 0.1 to 0.8 ft2/day. Based on the 2020 LNAPL 
mobility and recoverability assessment results, the Division gave approval to Marathon for the deactivation of 
recovery wells located on the main Refinery and approval to start three years of confirmation semi‐annual 
groundwater monitoring. To date 2 years of confirmation sampling has been completed and no exceedances of 
constituents of concern (COCs) have been observed in compliance wells.  

Historically LNAPL has been detected in TLR monitoring wells 01A and 02A. Monitoring well 01A is located 
approximately 8 feet south from recovery well RS‐W1A and well 02A is approximately 190 feet north from RS‐
W1A. Well locations are included on the Figure 2 TLR site map. The purpose of the recovery well RS‐W1 and 
replacement recovery well RS‐W1A is to maintain gradient control at the western edge of the TLR property in 
compliance with the CAP.  

2 
3.0 TRUCK LOADING RACK ACTIVE PUMPING GAUGING AND BAIL‐
DOWN TESTING
In June 2022 prior to the deactivation of recovery well RS‐W1A, LNAPL was gauged in well 02A at a thickness of 
0.73 feet which met the ASTM E2856‐13 Standard Guide for Estimation of LNAPL Transmissivity, recommended 
thickness of LNAPL to perform bail‐down testing is 0.5 feet. On June 30, 2022, Antea Group performed initial 
purging of the LNAPL from 02A and removed approximately 500 milliliters of LNAPL. Post purging gauging was 
performed and the measurements are summarized in Table 1. Post bail‐down LNAPL thickness in 02A showed no 
significant recovery of LNAPL through September 20, 2022. Results of the 02A bail‐down event show a lack of 
recovery of LNAPL in the well during the bail‐down test, indicating that LNAPL Tn is too low to be accurately 
measured utilizing ASTM bail‐down methods. 

4.0 TRUCK LOADING RACK POST PUMPING GAUGING
To evaluate the measurable LNAPL transmissivity in wells 01A and 02A, bail‐down testing was proposed to be 
evaluated under static groundwater conditions requiring the deactivation of recovery well RS‐W1A. After 
recovery well RS‐W1A was deactivated, the following field measurements were collected at monitoring wells 
01A and 02A on the schedule cited in the table below to evaluate post pumping groundwater conditions: 

Field Measurements Method Monitoring Wells Schedule
Water Table 
Elevation and 
LNAPL Thickness 
Interface 
Probe 
01A, 02A Weekly for one month then 
monthly for duration of 
transmissivity testing 

After static groundwater conditions are confirmed based on the weekly water table gauging events, 
transmissivity bail‐down testing was planned to be performed when sufficient LNAPL is detected in the wells.  

Recovery well RS‐W1A was shut down on September 22, 2022, gauging of groundwater and LNAPL was performed 
at wells 01A and 02A and recovery well RS‐W1A through May 2023. The graphs below show the changes in depth 
to groundwater and depth to LNAPL based on the 8 months of gauging data. A summary of the post pumping 
gauging data for wells 01A and 02A are attached as Tables 1 and 2. Historical groundwater elevation and 
measured LNAPL data for wells 01A and 02A as Charts 1 and 2. A complete log of historical groundwater elevation 
and measured LNAPL data for wells 01A and 02A is included as Appendix A. 

3 
Gauging data collected from the three wells indicates a gradual increase of water table elevation was observed 
with 01A and RS‐W1A increasing approximately 7 feet and 02A increasing approximately 4.5 feet. Measurable 
LNAPL was only detected in well 02A with a maximum thickness of 0.10 feet measured. As noted in the ASTM 
E2856‐13 Standard Guide for Estimation of LNAPL Transmissivity, the recommended thickness of LNAPL to 
perform bail down testing is 0.5 feet. Post pumping groundwater gauging data indicates no significant change in 
LNAPL occurrence or thicknesses when compared with the historical LNAPL gauging data. 
5.0 CONCLUSIONS AND RECOMMENDATIONS
•Bail‐down LNAPL testing performed on well 02A in June 2022, while recovery well RS‐W1A was still
active, showed no significant recovery of LNAPL thickness in the well during bail‐down testing. The lack
of LNAPL recovery indicates that LNAPL Tn is too low to be accurately measured utilizing ASTM bail‐
down methods.
•Groundwater gauging data, collected from wells 01A, 02A and RS‐W1A during 8 months of post
pumping monitoring, indicated an increase in groundwater elevations ranging from 4.5 feet in well 02A
to approximately 7 feet at wells 01A and RS‐W1A.
•No LNAPL was detected in wells RS‐W1A and 01A.
•Measurable LNAPL was only detected in well 02A with a maximum thickness of 0.10 feet measured.
•Based on the lack of LNAPL in 01A and the limited LNAPL thickness observed in 02A, bail‐down testing
was not feasible to calculate Tn.
0
2
4
6
8
10
12
14
16
18
20
9/20/2022 10/21/2022 11/21/2022 12/22/2022 1/22/2023 2/22/2023 3/25/2023 4/25/2023 5/26/2023
De
p
t
h
 fr
o
m
 TO
C
 (f
t
)
Date
Depth to Groundwater and LNAPL Post Pumping Shutdown
01A 02A Water 02A LNAPL RS‐W1A Pump Shutdown

4 

 Post pumping groundwater gauging data indicates no significant change in LNAPL occurrence or 
thicknesses when compared with the historical LNAPL gauging data. 

 The limited to non‐existent LNAPL in wells 02A and 01A, respectively, indicates very limited to no LNAPL 
transmissivity which indicates little if any LNAPL mobility, and no potential for LNAPL migration under 
ambient conditions. 

 Antea Group recommends continued LNAPL gauging of wells 01A and 02A under ambient conditions 
following a quarterly schedule and implementation of the post pumping semi‐annual confirmation 
groundwater monitoring plan. LNAPL gauging is recommended to be performed for one year and if 
LNAPL is measured at a thickness of 0.5 feet or greater bail‐down testing will be performed under 
ambient conditions and the results compared to the active pumping bail‐down testing performed in 
2022.  

6.0 REFERENCES 
(ITRC), Interstate Technology Regulatory Council. 2018. "LNAPL Update 3. Key LNAPL Concepts." LNAPL Update. 
Accessed February 25, 2021. https://lnapl‐3.itrcweb.org/3‐key‐lnapl‐
concepts/#:~:text=Mobility%20refers%20to%20the%20ability,the%20overall%20LNAPL%20body%20ed
ge. 
CL:AIRE. 2014. An Illustrated Handbook of LNAPL Transport and Fate in the Subsurface. London : Contaminated 
Land: Applications in Real Environments . 
Freeze, Allen R., and Cherry John A. 1979. Groundwater. Englewood Cliffs: Prentice‐Hall Inc. 
ITRC. 2019. Light Non‐Aqueous Phase Liguids (LNAPL Training Course. January 8. Accessed February 25, 2021. 
https://www.itrcweb.org/Training/ListEvents?topicID=13&subTopicID=18. 
—. 2009. ITRC – Evaluating LNAPL Remedial Technologies for Achieving Project Goals. December. Accessed 
March 18, 2021. https://www.itrcweb.org/GuidanceDocuments/LNAPL‐2.pdf. 
—. n.d. ITRC LNAPL Update. Accessed March 1, 2021. https://lnapl‐3.itrcweb.org/appendix‐c‐transmissivity‐tn‐
appendix/. 

Figures
Figure 1 – Site Location Map 
Figure 2 – Truck Loading Rack Site Map 

Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA,USGS, AeroGRID, IGN, and the GIS User Community, Esri, HERE, Garmin, (c)OpenStreetMap contributors
SITE LOCATION MAPTESORO REFINERY SALT LAKE CITY PROPERTIESMARATHON REFINERY, REMOTE TANK FARM AND TRUCK LOADING RACK SALT LAKE CITY, UTAH
FIGURE 1
PROJECT NO.
DATE
PREPARED BY
REVIEWED BY
REF SCALE
MAP SCALE
K019SLCRF2 JLH
0 1,000 2,000 3,000 4,000500Feet
$1:24,000
1 INCH = 2,000 FEET12/17/2021 SB
C:\Users\markb2\Antea USA, Inc\NCGH-Digital Solutions2021 - Geospatial - private - Geospatial - private\!TEMP GIS Files\Marathon\Marathon SLC Refinery\Project Number\Layout\SiteLocation_Aerial.mxd
Tesoro Refinery
Truck Loading Rack
Tesoro Remote Tank Farm
!5
!5
!5
!5!5
!5
!5
!<
@A
@A
@A
"J@?@?
@?
@?
@A
C1
MW92-05S
MW92-29S
MW-B3
RS-W1A 01A02A
0405
Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community
TRUCK LOADING RACK MONITORING NETWORKMARATHON REFINERY AND TRUCK LOADING RACK SALT LAKE CITY, UTAH
FIGURE 2
PROJECT NO.
DATE
PREPARED BY
REVIEWED BY
REF SCALE
MAP SCALE
K019SLCRF2 MB
0 50 100 150 20025Feet $
Legend
@A Monitoring Well Location (RFI) (MW92-11)
@?Shallow Well (Pre RFI) (75)
@A Former Monitoring Well Location
"J Recovery Well (Installed 1996-1997)
"c Piezometer (Installed 1996-1997)
!<Other Tesoro Monitoring Well Location (S-29)
!5 Gauge Only Well Location
!5 Gauge and Sample Well Location
Property Boundary
Recovery Trench
1:1,200
1 INCH = 100 FEET2/27/2023 SB
Z:\!GIS Projects\Marathon\Marathon SLC Refinery\Project Number\Layout\2022\Truck Loading Rack Monitoring Network.mxd
@AMW92-29M

Tables
Table 1– Well 02A Active Recovery Well Bail Down Gauging Data 
Table 2 – Well 01A Post Recovery Well Shut Down Gauging Data 
Table 3 – Well 02A Post Recovery Well Shut Down Gauging Data 

Well ID Date / Time
Time since last
measurement
Time since LNAPL
removal
TOC
Elevation (ft)
Water Level
Depth
(ft)
LNAPL Depth
(ft)
LNAPL
Thickness
(ft)
Water Level
Elevation* (ft)
Volume of LNAPL
Removed (mL)
Change in LNAPL
Thickness since last
measurement (ft)
Change in GW
Elevation post pump
shut off (ft)
02A 6/30/2022 13:54 - 4231.01 10.15 * 9.42 0.73 4221.4878 500 --
02A 6/30/2022 14:46 0 Days 0 Hrs 0 4231.01 9.68 ** 9.59 0.09 4221.41 - -0.64
02A 6/30/2022 15:47 0 Days 1 Hrs 0 Days 1 Hrs 4231.01 9.65 9.55 0.10 4221.45 - 0.01
02A 7/1/2022 10:53 0 Days 19 Hrs 0 Days 20 Hrs 4231.01 9.71 9.61 0.10 4221.39 - 0.00
02A 7/5/2022 15:34 4 Days 4 Hrs 5 Days 0 Hrs 4231.01 10.08 9.99 0.09 4221.01 - -0.01
02A 7/12/2022 10:31 6 Days 18 Hrs 11 Days 19 Hrs 4231.01 10.42 10.30 0.12 4220.69 - 0.03
02A 7/20/2022 10:47 8 Days 0 Hrs 19 Days 20 Hrs 4231.01 9.18 9.08 0.10 4221.92 - -0.02
02A 7/27/2022 10:32 6 Days 23 Hrs 26 Days 19 Hrs 4231.01 9.97 9.86 0.11 4221.13 - 0.01
02A 8/16/2022 0:00 19 Days 13 Hrs 46 Days 9 Hrs 4231.01 9.72 9.61 0.11 4221.38 - 0.00
02A 9/20/2022 12:49 35 Days 12 Hrs 81 Days 22 Hrs 4231.01 10.48 10.39 0.09 4220.61 --0.02
Well RS-W1A pump was turned off on 9/22 at approximately 15:55.
* Measurements collected prior to LNAPL removal
** Measurements collect immediately after LNAPL removal
ND = Not Detected
Table 1
Well 02A Active Recovery Well Bail Down Gauging Data
Truck Loading Rack
Marathon Salt Lake City Refinery
Well ID Date / Time
Time since last
measurement
Time since pump
shut down
TOC
Elevation (ft)
Water Level
Depth
(ft)
LNAPL
Detected?
Y/N
LNAPL Depth
(ft)
LNAPL
Thickness
(ft)
Water Level
Elevation* (ft)
Change in LNAPL
Thickness since last
measurement (ft)
Change in GW
Elevation post pump
shut off (ft)
01A 9/22/2022 15:55 2 Days 3 Hrs 0
01A 9/26/2022 15:12 6 Days 23 Hrs 3 Days 23 Hrs 4234.38 13.06 N ----4221.32 --1.83
01A 10/5/2022 11:59 8 Days 20 Hrs 12 Days 20 Hrs 4234.38 11.23 N ----4223.15 --3.66
01A 10/12/2022 17:22 7 Days 5 Hrs 20 Days 1 Hrs 4234.38 10.31 N ----4224.07 --4.58
01A 10/17/2022 14:51 4 Days 21 Hrs 24 Days 22 Hrs 4234.38 9.91 N ----4224.47 --4.98
01A 11/17/2022 12:49 30 Days 21 Hrs 55 Days 20 Hrs 4234.38 8.17 N ----4226.21 --6.72
01A 12/12/2022 14:59 25 Days 2 Hrs 80 Days 23 Hrs 4234.38 8.10 N ----4226.28 --6.79
01A 1/31/2023 11:34 49 Days 20 Hrs 130 Days 19 Hrs 4234.38 7.84 Y 7.84 Sheen 4226.54 Sheen observed 7.05
01A 2/24/2023 12:05 24 Days 0 Hrs 154 Days 20 Hrs 4234.38 8.09 N ----4226.29 --6.80
01A 3/20/2023 13:26 24 Days 1 Hrs 178 Days 21 Hrs 4234.38 7.53 N ----4226.85 --7.36
01A 4/19/2023 14:16 30 Days 0 Hrs 208 Days 22 Hrs 4234.38 7.53 N ----4226.85 --7.36
01A 5/3/2023 15:02 14 Days 0 Hrs 222 Days 23 Hrs 4234.38 7.74 N ----4226.64 --7.15
01A 6/19/2023 0:00 46 Days 8 Hrs 269 Days 8 Hrs 4234.38 7.89 N ----4226.49 --7.00
Well RS-W1A pump was turned off on 9/22 at approximately 15:55.
Table 2
Well 01A Post Recovery Well Shut Down Gauging Data
Truck Loading Rack
Marathon Salt Lake City Refinery
Pump Shut Down - No measurements collected.
Well ID Date / Time
Time since last
measurement
Time since pump
shut down
TOC
Elevation (ft)
Water Level
Depth
(ft)
LNAPL Depth
(ft)
LNAPL
Thickness
(ft)
Water Level
Elevation* (ft)
Volume of LNAPL
Removed (mL)
Change in LNAPL
Thickness since last
measurement (ft)
Change in GW
Elevation post pump
shut off (ft)
02A 9/22/2022 15:55 2 Days 3 Hrs 0
02A 9/26/2022 15:16 6 Days 2 Hrs 3 Days 23 Hrs 4231.01 9.57 9.47 0.10 4221.53 - 0.01 0.92
02A 10/5/2022 12:06 8 Days 20 Hrs 12 Days 20 Hrs 4231.01 8.51 8.43 0.08 4222.57 - -0.02 1.96
02A 10/12/2022 17:26 7 Days 5 Hrs 20 Days 1 Hrs 4231.01 7.87 7.86 0.01 4223.15 - -0.07 2.54
02A 10/17/2022 14:54 4 Days 21 Hrs 24 Days 22 Hrs 4231.01 7.62 7.61 0.01 4223.40 - 0.00 2.79
02A 11/17/2022 12:55 30 Days 22 Hrs 55 Days 21 Hrs 4231.01 6.15 ND ND 4224.86 - 0.00 4.25
02A 12/12/2022 15:01 25 Days 2 Hrs 80 Days 23 Hrs 4231.01 6.22 6.13 0.09 4224.87 - 0.08 4.26
02A 1/31/2023 11:38 49 Days 20 Hrs 130 Days 19 Hrs 4231.01 6.09 6.01 0.08 4224.99 - -0.01 4.38
02A 2/24/2023 12:08 24 Days 0 Hrs 154 Days 20 Hrs 4231.01 6.22 6.13 0.09 4224.87 - 0.01 4.26
02A 3/20/2023 13:32 24 Days 1 Hrs 178 Days 21 Hrs 4231.01 5.49 5.41 0.08 4225.59 - -0.01 4.98
02A 4/19/2023 14:20 30 Days 0 Hrs 208 Days 22 Hrs 4231.01 5.66 5.60 0.06 4225.40 - -0.02 4.79
02A 5/3/2023 15:05 14 Days 0 Hrs 222 Days 23 Hrs 4231.01 5.81 5.74 0.07 4225.26 - 0.01 4.65
02A 6/19/2023 0:00 46 Days 8 Hrs 269 Days 8 Hrs 4232.01 6.07 5.93 0.14 4226.06 -0.07 4.53
Well RS-W1A pump was turned off on 9/22 at approximately 15:55.
ND = Not Detected
Table 3
Well 02A Post Recovery Well Shut Down Gauging Data
Truck Loading Rack
Marathon Salt Lake City Refinery
Pump Shut Down - No measurements collected.

Charts
Chart 1 – Well 01/01A Historical Groundwater Elevation and LNAPL vs Time 
Chart 2 – Well 02/02A Historical Groundwater Elevation and LNAPL vs Time 

0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
4195.00
4200.00
4205.00
4210.00
4215.00
4220.00
4225.00
4230.00
5/1/1991 10/21/1996 4/13/2002 10/4/2007 3/26/2013 9/16/2018
LN
A
P
L

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Chart 1
Well 01/01A Historical Groundwater Elevation and LNAPL vs
Time Truck Loading Rack
Marathon Salt Lake City Refinery
Groundwater Elevation LNAPL Thickness
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
4210.00
4215.00
4220.00
4225.00
4230.00
4235.00
5/1/1991 10/21/1996 4/13/2002 10/4/2007 3/26/2013 9/16/2018
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Chart 2
Well 02/02A Historical Groundwater Elevation and LNAPL vs. Time
Truck Loading Rack
Marathon Salt Lake City Refinery
Groundwater Elevation LNAPL Thickness

Appendix A – Log of Historical Groundwater Elevation and Measured
LNAPL in wells 01/01A and 02/02A

Well 01/01A Historical Gauging Data
Truck Loading Rack
Maraton Salt Lake City Refinery
Well ID Date
Ground
Surface
Elevation
(ft amsl)
TOC
Elevation
(ft amsl)
Field Measured
LNAPL Depth
(ft below TOC)
Field Measured
Water Level
Depth
(ft below TOC)
Field Measured
Well Depth
(ft below TOC)
Ground
Water
Elevation
(ft amsl)
LNAPL
Elevation
LNAPL
Thickness
(ft)
Observation
01 6/15/1991 4228.43 4232.65 6.60 7.26 NM 4225.96 4226.05 0.66
01 7/15/1991 4228.43 4232.65 7.62 8.26 NM 4224.94 4225.03 0.64
01 9/15/1991 4228.43 4232.65 7.24 7.86 NM 4225.32 4225.41 0.62
01 12/15/1991 4228.43 4232.65 6.95 7.49 NM 4225.62 4225.70 0.54
01 3/15/1992 4228.43 4232.65 NM 17.09 NM 4215.56 NM
01 6/15/1992 4228.43 4232.65 NM 16.01 NM 4216.64 NM
01 9/15/1992 4228.43 4232.65 NM 17.22 NM 4215.43 NM
01 12/15/1992 4228.43 4232.65 NM 10.16 NM 4222.49 NM
01 3/15/1993 4228.43 4232.65 NM 8.70 NM 4223.95 NM
01 6/15/1993 4228.43 4232.65 NM 8.75 NM 4223.90 NM
01 9/15/1993 4228.43 4232.65 11.08 11.09 NM 4221.57 4221.57 0.01
01 12/15/1993 4228.43 4232.65 NM 11.58 NM 4221.07 NM
01 2/15/1994 4228.43 4232.65 NM 15.71 NM 4216.94 NM
01 5/15/1994 4228.43 4232.65 NM 17.23 NM 4215.42 NM
01 8/15/1994 4228.43 4232.65 NM 32.65 NM 4200.00 NM Dry
01 11/15/1994 4228.43 4232.65 NM 32.65 NM 4200.00 NM Dry
01 1/15/1995 4228.43 4232.65 NM 32.65 NM 4200.00 NM Dry
01 5/28/1996 4228.43 4232.65 NM 16.95 NM 4215.70 NM
01 12/4/1996 4228.43 4232.65 NM 16.81 NM 4215.84 NM
01 3/7/1997 4228.43 4232.65 15.65 15.68 NM 4217.00 4217.00 0.03
01 6/10/1997 4228.43 4232.65 NM 16.96 NM 4215.69 NM
01 3/19/1998 4228.43 4232.65 NM 13.25 NM 4219.40 NM
01 6/18/1998 4228.43 4232.65 NM 14.96 NM 4217.69 NM
01 9/10/1998 4228.43 4232.65 NM 16.94 NM 4215.71 NM
01 12/13/1998 4228.43 4232.65 NM 16.98 NM 4215.67 NM
01 3/5/2002 4228.43 4232.65 NM NM NM Dry Dry
01 6/13/2002 4228.43 4232.65 NM 16.90 NM 4215.75 NM Dry
01 9/11/2002 4228.43 4232.65 NM NM NM Dry Dry
01 12/4/2002 4228.43 4232.65 NM NM NM Dry Dry
01 3/4/2003 4228.43 4232.65 NM NM NM Dry DRY
01 6/17/2003 4228.43 4232.65 NM NM NM Dry
01 9/16/2003 4228.43 4232.65 NM 10.25 16.90 4222.40 NM No PC/GC
01 12/16/2003 4228.43 4232.65 NM 11.90 NM 4220.75 NM Trace product, unmeasurable
01 3/25/2004 4228.43 4232.65 NM 9.11 NM 4223.54 NM Distrib.
01 6/3/2004 4228.43 4232.65 NM 9.22 NM 4223.43 NM
No protector casing/No visible monument/3 T-
stakes/Distrib.
01 9/16/2004 4228.43 4232.65 9.92 9.92 NM 4222.73 4222.73 0.00 Distrib. SHEEN
01 1/6/2005 4228.43 4232.65 NM 8.45 NM 4224.20 NM Distrib.
01 3/23/2005 4228.43 4232.65 NM 8.13 NM 4224.52 NM Distrib.
01 6/21/2005 4228.43 4232.65 NM 7.56 NM 4225.09 NM Distrib.
01 9/19/2005 4228.43 4232.65 NM 9.06 NM 4223.59 NM Distrib.
01 12/12/2005 4228.43 4232.65 NM 15.18 NM 4217.47 NM Distrib.
01 3/7/2006 4228.43 4232.65 NM 14.69 NM 4217.96 NM
01 6/5/2006 4228.43 4232.65 NM 11.81 NM 4220.84 NM Distrib.
01 9/24/2006 4228.43 4232.65 NM 12.47 NM 4220.18 NM Distrib.
01 12/11/2006 4228.43 4232.65 NM 13.12 NM 4219.53 NM Distrib.
01 4/8/2007 4228.43 4232.65 NM 13.18 NM 4219.47 NM Distrib.
01 6/13/2007 4228.43 4232.65 NM 12.94 NM 4219.71 NM Distrib., slight odor
01 9/10/2007 4228.43 4232.65 NM 12.47 NM 4220.18 NM Distribution, slight odor
01 12/5/2007 4228.43 4232.65 NM 12.92 NM 4219.73 NM Distribution, slight odor
01 3/12/2008 4228.43 4232.65 NM 12.29 NM 4220.36 NM locked, behind the gate
01 6/2/2008 4228.43 4232.65 NM 12.98 NM 4219.67 NM
01 9/2/2008 4228.43 4232.65 NM 13.04 NM 4219.61 NM
01 12/8/2008 4228.43 4232.65 NM 12.57 NM 4220.08 NM
01 3/11/2009 4228.43 4232.65 NM 11.75 NM 4220.90 NM
01 6/9/2009 4228.43 4232.65 NM 11.49 NM 4221.16 NM
01 9/8/2009 4228.43 4232.65 NM 12.76 NM 4219.89 NM Biofouling/slime on probe/slight odor
01 12/8/2009 4228.43 4232.65 NM 12.81 NM 4219.84 NM
01 4/8/2010 4228.43 4232.65 NM 10.69 NM 4221.96 NM
01 6/10/2010 4228.43 4232.65 NM 10.62 NM 4222.03 NM
01 9/8/2010 4228.43 4232.65 NM 12.13 NM 4220.52 NM
01 12/2/2010 4228.43 4232.65 NM 10.95 NM 4221.70 NM
01 3/2/2011 4228.43 4232.65 NM 12.72 NM 4219.93 NM Marker tape installed for surveyor 1Q2011
01 6/8/2011 4228.43 4232.65 NM 11.13 NM 4221.52 NM Marker tape installed for surveyor 1Q2011
01 9/8/2011 4228.43 4232.65 NM 13.98 NM 4218.67 NM Marker tape installed for surveyor 1Q2011
01 12/13/2011 4228.43 4232.65 NM 13.48 NM 4219.17 NM Marker tape installed for surveyor 1Q2011
01 3/6/2012 4228.43 4232.65 NM 12.48 NM 4220.17 NM
01 6/5/2012 4228.43 4232.65 NM 12.77 NM 4219.88 NM
Well 01/01A Historical Gauging Data
Truck Loading Rack
Maraton Salt Lake City Refinery
Well ID Date
Ground
Surface
Elevation
(ft amsl)
TOC
Elevation
(ft amsl)
Field Measured
LNAPL Depth
(ft below TOC)
Field Measured
Water Level
Depth
(ft below TOC)
Field Measured
Well Depth
(ft below TOC)
Ground
Water
Elevation
(ft amsl)
LNAPL
Elevation
LNAPL
Thickness
(ft)
Observation
01 9/4/2012 4228.43 4232.65 NM 13.64 NM 4219.01 NM
01 12/3/2012 4228.43 4232.65 NM 13.44 NM 4219.21 NM
01 3/13/2013 4228.43 4232.65 NM 12.41 NM 4220.24 NM
01 6/12/2013 4228.43 4232.65 NM 12.60 NM 4220.05 NM
01 9/4/2013 4228.43 4232.65 NM 13.22 NM 4219.43 NM
01 12/4/2013 4228.43 4232.65 NM 13.15 NM 4219.50 NM
01 3/3/2014 4228.43 4232.65 NM 11.74 NM 4220.91 NM
01 6/10/2014 4228.43 4232.65 NM 14.12 NM 4218.53 NM
01 9/9/2014 4228.43 4232.65 NM 12.09 NM 4220.56 NM
01 12/10/2014 4228.43 4232.65 NM 12.80 NM 4219.85 NM
01 2/24/2015 4228.43 4232.65 NM 11.12 NM 4221.53 NM
01 6/3/2015 4228.43 4232.65 NM 12.77 NM 4219.88 NM
01 9/8/2015 4228.43 4232.65 NM 16.86 NM 4215.79 NM
01 12/16/2015 4228.43 4232.65 NM 15.86 NM 4216.79 NM
01 3/2/2016 4228.43 4232.65 NM 13.94 NM 4218.71 NM
01 6/9/2016 4228.43 4232.65 NM 14.82 NM 4217.83 NM
01 9/6/2016 4228.43 4232.65 12.44 12.44 NM 4220.21 4220.21 0.00 sheen
01 12/7/2016 4228.43 4232.65 NM 10.81 NM 4221.84 NM
01 3/8/2017 4228.43 4232.65 12.03 12.04 NM 4220.62 4220.62 0.01 product 1Q17
01 6/2/2017 4228.43 4232.65 NM 15.21 NM 4217.44 NM
01 9/5/2017 4228.43 4232.65 NM 18.50 NM 4214.15 NM
01 12/7/2017 4228.43 4232.65 NM 14.39 NM 4218.26 NM
01A 3/7/2018 4228.43 4234.38 NM 13.94 NM 4220.44 NM 1Q18
01A 6/7/2018 4228.43 4234.38 NM 10.25 NM 4224.13 NM 2Q18
01A 9/5/2018 4228.43 4234.38 NM 11.72 NM 4222.66 NM
01A 12/5/2018 4228.43 4234.38 NM 15.77 NM 4218.61 NM
01A 3/9/2019 4228.43 4234.38 NM 14.80 NM 4219.58 NM
01A 6/4/2019 4228.43 4234.38 NM 9.90 NM 4224.48 NM
01A 9/11/2019 4228.43 4234.38 NM 17.15 NM 4217.23 NM
01A 12/18/2019 4228.43 4234.38 8.19 8.20 NM 4226.19 4226.19 0.01
01A 3/17/2020 4228.43 4234.38 16.51 16.53 NM 4217.87 4217.87 0.02
01A 6/15/2020 4228.43 4234.38 NM 15.20 NM 4219.18 NM
01A 9/17/2020 4228.43 4234.38 NM 15.52 NM 4218.86 NM
01A 12/3/2020 4228.43 4234.38 NM 14.46 NM 4219.92 NM
01A 3/9/2021 4228.43 4234.38 NM 14.93 NM 4219.45 NM
01A 6/8/2021 4228.43 4234.38 NM 15.16 NM 4219.22 NM
01A 9/13/2021 4228.43 4234.38 NM 14.85 NM 4219.53 NM
01A 12/8/2021 4228.43 4234.38 NM 14.00 NM 4220.38 NM
01A 3/8/2022 4228.43 4234.38 NM 15.47 NM 4218.91 NM
01A 6/3/2022 4228.43 4234.38 NM 11.32 NM 4223.06 NM
01A 9/20/2022 4228.43 4234.38 NM 14.89 NM 4219.49 NM
01A 9/26/2022 4228.43 4234.38 NM 13.06 NM 4221.32 NM
01A 10/5/2022 4228.43 4234.38 NM 11.23 NM 4223.15 NM
01A 10/12/2022 4228.43 4234.38 NM 10.31 NM 4224.07 NM
01A 10/17/2022 4228.43 4234.38 NM 9.91 NM 4224.47 NM
01A 11/17/2022 4228.43 4234.38 NM 8.17 NM 4226.21 NM
01A 12/12/2022 4228.43 4234.38 NM 8.10 NM 4226.28 NM
01A 1/31/2023 4228.43 4234.38 7.84 7.85 NM 4226.54 4226.54 0.01 Product detected
01A 2/24/2023 4228.43 4234.38 NM 8.09 NM 4226.29 NM
01A 3/20/2023 4228.43 4234.38 NM 7.53 NM 4226.85 NM
01A 4/19/2023 4228.43 4234.38 NM 7.53 NM 4226.85 NM
01A 5/3/2023 4228.43 4234.38 NM 7.74 NM 4226.64 NM
ft = feet
TOC = Top of Casing
amsl = above mean sea level
NM = Not Measured
Well 02/02A Historical Gauging Data
Truck Loading Rack
Maraton Salt Lake City Refinery
Well ID Date
Ground
Surface
Elevation
(ft amsl)
TOC
Elevation
(ft amsl)
Field Measured
LNAPL Depth
(ft below TOC)
Field Measured
Water Level
Depth
(ft below TOC)
Field
Measured
Well Depth
(ft below TOC)
Ground
Water
Elevation
(ft amsl)
LNAPL
Elevation
LNAPL
Thickness
(ft)
Observation
02 6/15/1991 4225.62 4229.67 2.60 2.67 NM 4227.06 4227.07 0.07
02 7/15/1991 4225.62 4229.67 3.70 3.71 NM 4225.97 4225.97 0.01
02 9/15/1991 4225.62 4229.67 2.51 2.90 NM 4227.11 4227.16 0.39
02 12/15/1991 4225.62 4229.67 2.14 2.27 NM 4227.51 4227.53 0.13
02 6/15/1992 4225.62 4229.67 7.63 9.05 NM 4221.84 4222.04 1.42
02 12/15/1992 4225.62 4229.67 NM 5.10 NM 4224.57 NM
02 3/15/1993 4225.62 4229.67 1.70 1.75 NM 4227.96 4227.97 0.05
02 6/15/1993 4225.62 4229.67 2.44 2.45 NM 4227.23 4227.23 0.01
02 9/15/1993 4225.62 4229.67 4.65 4.99 NM 4224.97 4225.02 0.34
02 12/15/1993 4225.62 4229.67 4.04 4.22 NM 4225.60 4225.63 0.18
02 2/15/1994 4225.62 4229.67 2.96 2.97 NM 4226.71 4226.71 0.01
02 5/15/1994 4225.62 4229.67 1.60 1.61 NM 4228.07 4228.07 0.01
02 8/15/1994 4225.62 4229.67 12.58 12.71 NM 4217.07 4217.09 0.13
02 11/15/1994 4225.62 4229.67 NM 1.69 NM 4227.98 NM
02 1/15/1995 4225.62 4229.67 3.90 3.97 NM 4225.76 4225.77 0.07
02 8/30/1995 4225.62 4229.49 11.73 12.11 NM 4217.71 4217.76 0.38 Previous survey data
02 11/27/1995 4225.62 4229.49 4.63 4.72 NM 4224.85 4224.86 0.09 Previous survey data
02 2/28/1996 4225.62 4229.67 2.15 2.16 NM 4227.52 4227.52 0.01 Repaired well
02 5/28/1996 4225.62 4229.67 NM 2.28 NM 4227.39 NM Trace
02 9/11/1996 4225.62 4229.67 9.32 9.33 NM 4220.35 4220.35 0.01
02 12/4/1996 4225.62 4229.67 2.89 2.90 NM 4226.78 NM 0.01 SHEEN
02 3/7/1997 4225.62 4229.67 2.87 2.87 NM 4226.80 NM 0.00 Sheen
02 6/10/1997 4225.62 4229.49 2.73 2.73 NM 4226.76 4226.76 0.00
02 9/7/1997 4225.62 4229.67 NM 4.45 NM 4225.22 NM
02 11/26/1997 4225.62 4229.67 NM 3.15 NM 4226.52 NM
02 3/19/1998 4225.62 4229.67 NM 2.48 NM 4227.19 NM
02 6/18/1998 4225.62 4229.67 NM 2.34 NM 4227.33 NM
02 9/10/1998 4225.62 4229.67 NM 2.89 NM 4226.78 NM
02 12/13/1998 4225.62 4229.67 NM 3.65 NM 4226.02 NM
02 3/19/1999 4225.62 4229.67 NM 3.53 NM 4226.14 NM
02 6/22/1999 4225.62 4229.67 4.58 4.58 NM 4225.09 NM 0.00 Trace free product
02 9/1/1999 4225.62 4229.67 NM 5.64 NM 4224.03 NM
02 3/21/2000 4225.62 4229.67 3.72 3.72 NM 4225.95 NM 0.00 free product trace
02 5/31/2000 4225.62 4229.67 4.03 4.03 NM 4225.64 NM 0.00 Trace
02 9/20/2000 4225.62 4229.67 5.09 5.09 NM 4224.58 NM 0.00 Trace
02 11/29/2000 4225.62 4229.67 4.81 4.82 NM 4224.86 4224.86 0.01
02 3/13/2001 4225.62 4229.67 3.74 3.75 NM 4225.93 4225.93 0.01
02 3/21/2001 4225.62 4229.67 3.71 3.72 NM 4225.96 4225.96 0.01 free product trace
02 5/21/2001 4225.62 4229.67 3.80 3.86 NM 4225.86 4225.87 0.06
02 8/31/2001 4225.62 4229.67 NM 4.38 NM 4225.29 NM
02 11/7/2001 4225.62 4229.67 3.02 3.02 NM 4226.65 NM 0.00 Sheen, well in standing water
02 3/5/2002 4225.62 4229.67 NM 3.84 NM 4225.83 NM
02 6/13/2002 4225.62 4229.67 NM 4.51 NM 4225.16 NM Dry
02 9/11/2002 4225.62 4229.67 NM 3.76 NM 4225.91 NM
02 12/4/2002 4225.62 4229.67 NM 3.31 NM 4226.36 NM
02 3/4/2003 4225.62 4229.67 NM 4.91 NM 4224.76 NM
02 6/17/2003 4225.62 4229.67 NM 3.32 NM 4226.35 NM
02 9/16/2003 4225.62 4229.67 NM 1.50 13.90 4228.17 NM No PC/Poor Condition/ Broken stick-up
02 12/16/2003 4225.62 4229.67 NM 1.36 NM 4228.31 NM well is broken off ~5", bgs in gravel
02 3/25/2004 4225.62 4229.67 NM NM NM NM Distrib. Stick-up broken at ground surface. DTW=0.92
02 12/4/2004 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 3/23/2005 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 6/21/2005 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 9/19/2005 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 12/10/2005 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 3/4/2006 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 6/3/2006 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 9/21/2006 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 12/4/2006 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 4/7/2007 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 6/9/2007 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 9/10/2007 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 12/5/2007 4225.62 4229.67 NM NM NM NM CASING BROKEN OFF, AWAITING REPAIR
02 3/12/2008 4225.62 4229.67 2.14 2.15 NM 4227.53 4227.53 0.01 CASING BROKEN OFF, REPAIRED
02 6/2/2008 4225.62 4229.67 NM 2.81 NM 4226.86 NM CASING BROKEN OFF, REPAIRED, Locked behind gate
02 9/2/2008 4225.62 4229.67 NM 2.98 NM 4226.69 NM CASING BROKEN OFF, REPAIRED, Locked behind gate
02 12/8/2008 4225.62 4229.67 NM 4.29 NM 4225.38 NM Casing repaired, locked behind gate
02 3/11/2009 4225.62 4229.67 NM 2.85 NM 4226.82 NM Casing repaired, locked behind gate
02 6/9/2009 4225.62 4229.67 NM 2.81 NM 4226.86 NM Casing repaired, locked behind gate
02 9/8/2009 4225.62 4229.67 NM 5.08 NM 4224.59 NM
Casing repaired, locked behind gate, in 3Q09 asked personnel to
unlock
02 12/8/2009 4225.62 4229.67 NM 5.11 NM 4224.56 NM Casing repaired, locked behind gate
02 4/8/2010 4225.62 4229.67 NM 2.46 NM 4227.21 NM
02 6/10/2010 4225.62 4229.67 NM 3.24 NM 4226.43 NM
02 9/8/2010 4225.62 4229.67 NM 4.30 NM 4225.37 NM
02 12/2/2010 4225.62 4229.67 2.88 2.88 NM 4226.79 4226.79 0.00 SHEEN-4Q
Well 02/02A Historical Gauging Data
Truck Loading Rack
Maraton Salt Lake City Refinery
Well ID Date
Ground
Surface
Elevation
(ft amsl)
TOC
Elevation
(ft amsl)
Field Measured
LNAPL Depth
(ft below TOC)
Field Measured
Water Level
Depth
(ft below TOC)
Field
Measured
Well Depth
(ft below TOC)
Ground
Water
Elevation
(ft amsl)
LNAPL
Elevation
LNAPL
Thickness
(ft)
Observation
02 3/2/2011 4225.62 4229.67 NM 4.47 NM 4225.20 NM Marker tape installed for surveyor 1Q2011
02 6/8/2011 4225.62 4229.67 NM 4.36 NM 4225.31 NM Marker tape installed for surveyor 1Q2011
02 9/8/2011 4225.62 4229.67 NM 6.30 NM 4223.37 NM Marker tape installed for surveyor 1Q2011
02 12/13/2011 4225.62 4229.67 NM 5.61 NM 4224.06 NM Marker tape installed for surveyor 1Q2011
02 3/6/2012 4225.62 4229.67 NM 3.17 NM 4226.50 NM
02 6/5/2012 4225.62 4229.67 NM 6.21 NM 4223.46 NM
02 9/4/2012 4225.62 4229.67 NM NM NM NM Unable to access well, gate locked with shop key 3Q12
02 12/3/2012 4225.62 4229.67 NM 4.47 NM 4225.20 NM
02 3/13/2013 4225.62 4229.67 NM 4.45 NM 4225.22 NM
02 6/12/2013 4225.62 4229.67 NM 4.86 NM 4224.81 NM
02 9/4/2013 4225.62 4229.67 NM 6.16 NM 4223.51 NM
02 12/4/2013 4225.62 4229.67 NM 6.22 NM 4223.45 NM
02 3/3/2014 4225.62 4229.67 NM 3.81 NM 4225.86 NM
02 6/10/2014 4225.62 4229.67 5.61 5.71 NM 4224.05 4224.06 0.10
02 9/9/2014 4225.62 4229.67 8.55 8.62 NM 4221.11 4221.12 0.07 Product 3Q14
02 12/10/2014 4225.62 4229.67 9.16 9.26 NM 4220.50 4220.51 0.10 Product 3Q14 and 4Q14
02 2/24/2015 4225.62 4229.67 7.94 8.03 NM 4221.72 4221.73 0.09 Product 3Q14, 4Q14, and 1Q15
02 6/3/2015 4225.62 4229.67 8.69 8.71 NM 4220.98 4220.98 0.02 Product 3Q14, 4Q14, 1Q15, 2Q15
02 9/8/2015 4225.62 4229.67 11.51 11.54 NM 4218.16 4218.16 0.03 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15
02 12/16/2015 4225.62 4229.67 10.85 10.91 NM 4218.81 4218.82 0.06 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15,4Q15
02 3/2/2016 4225.62 4229.67 9.59 9.69 NM 4220.07 4220.08 0.10 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15,4Q15
02 6/9/2016 4225.62 4229.67 8.60 8.71 NM 4221.05 4221.07 0.11 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15,4Q15
02 9/6/2016 4225.62 4229.67 8.98 8.99 NM 4220.69 4220.69 0.01 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15,4Q15,2Q16
02 12/7/2016 4225.62 4229.67 8.81 8.91 NM 4220.85 4220.86 0.10 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15,4Q15,2Q16, 4Q16
02 3/8/2017 4225.62 4229.67 8.04 8.17 NM 4221.61 4221.63 0.13 Product 3Q14-1Q17
02 6/2/2017 4225.62 4229.67 10.06 10.22 NM 4219.59 4219.61 0.16 Product 3Q14-,4Q15,2Q16, 4Q16, 2Q17
02 9/5/2017 4225.62 4229.67 12.05 12.25 NM 4217.59 4217.62 0.20 Product 3Q14, 4Q14, 1Q15, 2Q15, 3Q15,4Q15,2Q16, 4Q16
02 12/7/2017 4225.62 4229.67 10.03 10.22 NM 4219.61 4219.64 0.19 Product 4Q17
02A 3/7/2018 4225.62 4231.01 8.85 9.10 NM 4222.12 4222.16 0.25 1Q18
02A 6/7/2018 4225.62 4231.01 7.38 7.39 NM 4223.63 4223.63 0.01 2Q18
02A 9/5/2018 4225.62 4231.01 NM 8.29 NM 4222.72 NM
02A 11/13/2018 4225.62 4231.01 NM 10.01 20.85 4221.00 NM
02A 12/5/2018 4225.62 4231.01 NM 11.16 NM 4219.85 NM
02A 3/9/2019 4225.62 4231.01 NM 9.49 NM 4221.52 NM
02A 6/4/2019 4225.62 4231.01 NM 6.95 NM 4224.06 NM
02A 9/11/2019 4225.62 4231.01 NM 11.48 NM 4219.53 NM
02A 12/18/2019 4225.62 4231.01 12.83 12.84 NM 4218.18 4218.18 0.01
02A 3/17/2020 4225.62 4231.01 10.04 10.07 NM 4220.97 4220.97 0.03
02A 6/15/2020 4225.62 4231.01 NM 9.77 NM 4221.24 NM
02A 9/17/2020 4225.62 4231.01 9.70 9.73 NM 4221.31 4221.31 0.03
02A 12/3/2020 4225.62 4231.01 10.18 10.20 NM 4220.83 4220.83 0.02
02A 3/9/2021 4225.62 4231.01 9.71 9.79 NM 4221.29 4221.30 0.08
02A 6/8/2021 4225.62 4231.01 9.82 10.18 NM 4221.14 4221.19 0.36
02A 9/13/2021 4225.62 4231.01 9.75 10.34 NM 4221.18 4221.26 0.59
02A 12/8/2021 4225.62 4231.01 9.69 10.34 NM 4221.23 4221.32 0.65
02A 3/8/2022 4225.62 4231.01 10.01 10.02 NM 4221.00 4221.00 0.01
02A 6/3/2022 4225.62 4231.01 8.08 8.83 NM 4222.83 4222.93 0.75
02A 6/30/2022 4225.62 4231.01 9.42 10.15 NM 4221.49 4221.59 0.73
02A 7/1/2022 4225.62 4231.01 9.61 9.71 NM 4221.39 4221.40 0.10
02A 7/5/2022 4225.62 4231.01 9.99 10.08 NM 4221.01 4221.02 0.09
02A 7/12/2022 4225.62 4231.01 10.30 10.42 NM 4220.69 4220.71 0.12
02A 7/20/2022 4225.62 4231.01 9.08 9.18 NM 4221.92 4221.93 0.10
02A 7/27/2022 4225.62 4231.01 9.86 9.97 NM 4221.13 4221.15 0.11
02A 8/16/2022 4225.62 4231.01 9.61 9.72 NM 4221.38 4221.40 0.11
02A 9/20/2022 4225.62 4231.01 10.39 10.48 NM 4220.61 4220.62 0.09
02A 9/26/2022 4225.62 4231.01 9.47 9.57 NM 4221.53 4221.54 0.10
02A 10/5/2022 4225.62 4231.01 8.43 8.51 NM 4222.57 4222.58 0.08
02A 10/12/2022 4225.62 4231.01 7.86 7.87 NM 4223.15 4223.15 0.01
02A 10/17/2022 4225.62 4231.01 7.62 7.62 NM 4223.39 4223.39 0.00
02A 11/17/2022 4225.62 4231.01 NM 6.15 NM 4224.86 NM
02A 12/12/2022 4225.62 4231.01 6.13 6.22 NM 4224.87 4224.88 0.09
02A 1/31/2023 4225.62 4231.01 6.01 6.09 NM 4224.99 4225.00 0.08
02A 2/24/2023 4225.62 4231.01 6.13 6.22 NM 4224.87 4224.88 0.09
02A 3/20/2023 4225.62 4231.01 5.41 5.49 NM 4225.59 4225.60 0.08
02A 4/19/2023 4225.62 4231.01 5.60 5.66 NM 4225.40 4225.41 0.06
02A 5/3/2023 4225.62 4231.01 5.74 5.81 NM 4225.26 4225.27 0.07
ft = feet
TOC = Top of Casing
amsl = above mean sea level
NM = Not Measured
bgs = below ground surface

1 

Marathon Refinery Truck
Loading Rack

Salt Lake City, UT
 Groundwater Monitoring Plan 
PREPARED FOR
Marathon Petroleum Company  

PREPARED BY
Antea Group, Park City, UT 

July 17, 2023 

Project # K021SLCRF 
i 
Contents
1.0 Purpose .......................................................................................................................................................... 1 
2.0 Truck Loading Rack Sampling Scope ................................................................................................................ 1 
4.0 Data Evaluation and Reporting ...................................................................................................................... 2 
5.0 Field Procedures ............................................................................................................................................ 2 
6.0 Schedule ......................................................................................................................................................... 2 
Table
Table 6‐1 ‐ Proposed Constituents of Concern (COC) for Groundwater for Confirmation Monitoring, Tesoro 
Corrective Action Plan  
Figures
Figure 1 ‐ Proposed  Truck Loading Rack Groundwater Sampling Plan, Marathon Refinery 
1 
Marathon Salt Lake City Refinery
Truck Loading Rack Groundwater Monitoring Plan 
1.0 PURPOSE
Antea®Group, on behalf of Tesoro Refining & Marketing Company LLC, a part of Marathon Petroleum Company 
LP (Marathon), has prepared the following proposed groundwater monitoring plan scope changes at the 
Marketing Terminal, aka Truck Loading Rack (TLR) groundwater sampling scope.  
2.0 TRUCK LOADING RACK SAMPLING SCOPE
The proposed changes to the TLR sampling scope are in accordance with the Corrective Action Plan (CAP) post 
groundwater recovery system shutdown confirmation groundwater sampling guidelines. These guidelines are 
presented in Section 6.2 of the CAP. All TLR groundwater sampling results have indicated that the benzene 
concentrations were below the CAP Groundwater Protection Standards (GPS) criteria of 2.9 mg/L in 2022 and 
have been below the GPS in all annual sampling performed since 2003.  
The sampling plan includes select compliance wells that have been sampled annually during the active 
groundwater recovery work, two off‐site downgradient sentinel wells, and additional wells located within the 
TLR which were selected to further evaluate the residual dissolved phase plume and attenuation rates of 
constituents of concern (COCs). Additionally, quarterly gauging will be performed for one year at wells 01A and 
02A which have historically contained measurable thicknesses of LNAPL. If LNAPL is measured at a thickness of 
0.5 feet or greater, LNAPL bail‐down testing will be performed, and gauging data collected to evaluate the 
residual LNAPL transmissivity under ambient conditions. Prior to starting the quarterly gauging, absorbent 
booms will be placed in both wells to remove residual LNAPL that is trapped in well boreholes and sand packs. 
The absorbent booms will be installed for two months prior to the first gauging event and removed two days 
prior to the initial gauging data is being collected.   
The proposed compliance wells to be sampled semi‐annually are included below:  
Compliance Wells Constituents of
Concern
Methods Monitoring Wells
Benzene, naphthalene, arsenic, 
cadmium, lead (SVOCs*) 
EPA 8260B 
EPA 8270C‐SIM 
EPA 6010B 
On‐site (MW92‐29S, MW‐B3) 
Sentinel (MW92‐27S, MW92‐28S) 
*SVOCs ‐ Semi‐Volatile Organic Compounds. A complete list of COCs is included in Table 6‐1 of the CAP and attached to this workplan. 
Additional wells to be gauged quarterly for the presence of LNAPL are listed below (quarterly gauging will be 
performed for one year):  
Field Measurements Method Monitoring Wells
LNAPL thickness Interface probe 01A, 02A  
Additional wells to be sampled semi‐annually to further evaluate the residual dissolved phase plume stability 
and attenuation rates are listed below:  
Constituents of Concern Method Monitoring Wells
BTEXN EPA 8260B Downgradient (01A, 02A) 

2 

Attached as Figure 1 is the Refinery and TLR site map showing the proposed wells to be sampled.  

4.0 DATA EVALUATION AND REPORTING
Groundwater monitoring data will be utilized to further evaluate the residual dissolved phase plume stability 
and attenuation rates of COCs. Additionally, the groundwater data collected from downgradient off‐site sentinel 
wells will provide assurance that risk to off‐site receptors remain below federal EPA VISL criteria. If benzene is 
detected in a sentinel well in excess of 0.00159 mg/L for two consecutive sampling events, a restart of corrective 
action will be implemented. Due to the age of the recovery well infrastructure and advancement of remedial 
technologies, alternative corrective action approaches to enhance the degradation rates of COCs in groundwater 
will be evaluated and may not include the restart of the pumping well. 

Groundwater monitoring results will be summarized in the annual status report describing the field activities, 
discussion of results, conclusions, and recommendations for additional scope considerations. The annual status 
report will be submitted to the UDEQ, Division of Waste Management and Radiation Control (DWMRC) by March 
1 of the following year.  
5.0 FIELD PROCEDURES
The following procedures summarize activities required to complete the proposed groundwater sampling plan:  
 Measure groundwater elevations and LNAPL thickness in all wells to be sampled using an interface 
probe.  
 Purge each monitoring well using low‐flow sampling methods at a flow rate of 1 liter/minute or less 
until field parameters stabilize. 
 Measure field parameters of temperature, specific conductivity, dissolved oxygen (DO), oxidation‐
reduction potential (ORP), and pH at each well while purging using a YSI meter/probe and flow cell.  
 Collect groundwater samples using a low‐flow sampling technique at a flow rate at 300 ml/minute or 
less. Groundwater samples will be shipped on ice to Pace National Labs under standard chain‐of‐
custody protocols for standard turnaround.  
6.0 SCHEDULE
The semi‐annual groundwater sampling plan will be performed for three years per CAP Section 6.2. During the 
initial three years of groundwater monitoring, the TLR recovery well, and pumping infrastructure will remain 
available for restart. The initial three years of semi‐annual groundwater sampling will be performed in May and 
September. The reporting schedule will not change with the annual status report submitted to the DWMRC by 
March 1 of the following year. At the conclusion of the three years of semi‐annual groundwater monitoring, 
assuming that a restart of pumping or alternative corrective actions are not required, Marathon will prepare a 
new groundwater monitoring plan for DWMRC review and approval.  

Table

Table 6‐1 Proposed Constituents of Concern (COC) for Groundwater for Confirmation Monitoring  
Tesoro Corrective Action Plan

1 ‐Methylnaphthalene  
2‐Methylnaphthalene  
Acenaphthylene  
Arsenic  
Benzene  
Benzo(a)anthracene  
Benzo(a)pyrene  
Benzo(b)fluoranthene  
Benzo(ghi)perylene  
Benzo(k)fluoranthene  
Cadmium  
Dibenzo(a,h)anthracene  
Indeno(l,2,3‐cd)pyrene 
Lead  
Naphthalene  
Phenanthrene  

Source:
RCRA Facility investigation and Risk Assessment Report, Revision May 9, 2003, Section 8 & Table 8‐7 

Figures
Figure 1 ‐ Proposed TLR Groundwater Sampling Plan, Marathon Refinery 

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Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community
REFINERY AND TRUCK LOADING RACK MONITORING NETWORKMARATHON REFINERY AND REMOTE TANK FARMSALT LAKE CITY, UTAH
FIGURE 1
PROJECT NO.
DATE
PREPARED BY
REVIEWED BY
REF SCALE
MAP SCALE
K019SLCRF2 MB
0 260 520 780 1,040130Feet $
Legend
@A Monitoring Well Location (RFI) (MW92-11)
@?Shallow Well (Pre RFI) (75)
@A Former Monitoring Well Location
"J Recovery Well (Installed 1996-1997)
"c Piezometer (Installed 1996-1997)
!<Other Tesoro Monitoring Well Location (S-29)
!Central Plume Well
!Downgradient Well
!Upgradient Well
!Compliance Well
!Downgradient Sentinel Wells
Property Boundary
Recovery Trench
1:6,000
1 INCH = 500 FEET7/11/2023 SB
Z:\!GIS Projects\Marathon\Marathon SLC Refinery\Project Number\Layout\2022\Refinery Truck Loading Monitoring Network.mxd
*