DERR-2024-009345

Rockwell Solutions, Inc., 718 E. Bridger Lane, Elk Ridge, UT 84651, 801-361-2930, [e-mail]
Rockwell Solutions, Inc.
718 Bridger Lane
Elk Ridge, UT 84651
[phone]
July 19, 2024

Mr. Jay Cahoon
Holiday Oil
3115 West 2100 South
Salt Lake City, UT 84119

Re: Soil Sampling
Holiday Oil #30, 3215 W 5400 South, Taylorsville, Utah
Facility ID: 4001380, Release ID: MTY

Dear Mr. Cahoon:

Rockwell Solutions, Inc. has completed soil sampling activities as requested by the Division of
Environmental Response and Remediation (DERR) in a letter dated May 15, 2024.

BACKGROUND

During the removal of underground storage tanks (USTs) at the above-referenced site on May 17,
2011, one of the closure samples exceeded Tier 1 screening levels. In response, the area around the
sampling location was overexcavated in an attempt to remove impacted soil. A total of 323.59 tons
were removed from the site and disposed of at ET Technologies.

Soil samples were collected on each side and on the bottom of the overexcavation. The side wall
samples were collected at a depth of approximately eighteen feet. The sample collected on the
south side of the overexcavation was below Tier 1 levels. All other samples exceeded Tier 1 levels.
Four borings were advanced in October 2011 around the perimeter of the excavation area to define
the horizontal extent of contamination.

On July 11, 2024, a single boring was advanced to define the upper and lower limits of residual
petroleum in the soil and to determine if groundwater has been impacted. The boring location is
shown on Figure 1.

METHODOLOGY

Boring B-101 was placed on the south side of the northwest dispenser in the approximate area of
soil sample “Overex-E”. Direct Push Services was employed as the direct-push contractor under
the supervision of a Rockwell Solutions representative.

Five-foot soil core samples were collected continuously. A portion of the soil core was put in a zip-
lock baggie to allow hydrocarbons to volatilize. The air in the zip lock baggie was then screened
Soil Sampling Report
Holiday Oil #30, UST No. 4001380, Taylorsville, Utah
Rockwell Solutions, Inc., 718 E. Bridger Lane, Elk Ridge, UT 84651, 801-361-2930, [e-mail]
2
with a photoionization detector (PID). Samples were collected in the area of the previous sample at
eighteen feet below grade (bg), a sample at thirty feet bg at the highest PID reading, and a sample at
fifty feet where PID readings indicated soil was no longer impacted. The samples were submitted
for laboratory analysis of MTBE, benzene, toluene, ethylbenzene, xylenes, naphthalene (MBTEXN)
and total petroleum hydrocarbons-gasoline range organics (TPH-GRO) using EPA Method 8260b
and TPH-diesel range organics (TPH-DRO) using EPA Method 8015b. Chemtech Ford conducted
laboratory analyses.

RESULTS

Soil Type
Soil type was evaluated during the subsurface investigation by field analysis of soil samples. In
general the soil at the site consists of silt (ML) and silty clay (CL) from ground surface to
approximately ten feet below grade, a sand layer (SW) from approximately ten to eighteen feet
below grade (bg), and a silt (ML) layer from eighteen feet to approximately forty-one feet bg. A
sand layer is present from forty-one to forty-four feet bg, and from forty-eight feet to at least fifty
feet bg. A silt layer is present from forty-four to forty eight feet bg. Groundwater was not
encountered. A boring log is attached.

Soil Analytical Results
Table 1 lists the analytical results of the soil samples collected during the tank closure,
overexcavation, and subsurface investigations. The sample collected from B-101 at eighteen feet bg
shows a significant decrease in hydrocarbons since “Overex-E” sample was collected in 2011.

The sample at thirty feet bg contained hydrocarbons exceeding Tier 1 levels. The sample collected
at fifty feet bg did not contain detectable hydrocarbons. The laboratory analytical reports and
chain-of-custody records for soil samples collected during the subsurface investigation are attached.
PID readings are shown on the boring logs.

Depth to Groundwater
DERR records for the former 7-11 (UST No. 4001010) on the northeast corner of the 5400
South/3200 West intersection, approximately 300 feet northeast of the subject property, show depth
to water was 71 feet bg.

CONCLUSIONS

Based on the soil samples collected on July 11, 2024, and other historic data, Rockwell Solutions
concludes the following:
 Hydrocarbons at approximately eighteen feet bg have significantly decreased since 2011
 Hydrocarbons exceeding Tier 1 levels remain in the soil sample collected at thirty feet bg
 The vertical extent of contamination has been defined and is at or less than fifty feet bg
 Impacted soil appears limited to the area around the current UST basin and western
dispensers
 Groundwater is approximately seventy feet deep

Soil Sampling Report
Holiday Oil #30, UST No. 4001380, Taylorsville, Utah
Rockwell Solutions, Inc., 718 E. Bridger Lane, Elk Ridge, UT 84651, 801-361-2930, [e-mail]
3
Because the vertical and horizontal extents have been defined to the area around the UST basin and
western dispensers, and groundwater has likely not been impacted, Rockwell Solutions recommends
the site be evaluated for closure (No Further Action).

Please feel free to contact me should you have any questions or concerns.

Sincerely,

David S. Hansen
Rockwell Solutions, Inc.
Certified UST Consultant CC130

cc: Eileen Brennan, DERR
5400 South
3200 West
SS-NW, 15’
Approx. scale in feet
00 25
Figure 1
olid y Oil #H a 30
32 est 400 o th15 W 5 S u
Ta s , Uylorvilletah
Sit Mape
SS-SW, 16’
SS-NE, 17’
SS-SE, 17’
USC-1, 17’
SS-SE, 20’
Store
Soi Sa p i g L c iolmlnoatnatWer
Gas
Sewer
lec ricEt
T ephonele
Overex-N, 18’
Overex-E, 18’
Overex-S, 18’
Overex-W, 18’
Overex-B, 22’
Overexcavation Area
orm D nSt rai
SS-P2, 3’SS-P3, 3’
SS-P1, 3’SS-P4, 3’
SB-2
SB-1
SB-3
SB-4
l o ng ocat nSoi B ri L io
B-101
Sample
Depth
(feet) Date
Benzene
(mg/kg)
Toluene
(mg/kg)
Ethylbenzene
(mg/kg)
Xylenes
(mg/kg)
Naphthalene
(mg/kg)
MTBE
(mg/kg)
TPH-GRO
(mg/kg)
TPH-DRO
(mg/kg)
SS-SE, 17 17 5/17/2011 <0.125 <0.125 1.24 7.68 4.47 <0.125 483 NA
SS-SE, 20 20 5/17/2011 0.256 4.82 11.1 66.5 7.28 <0.125 850 NA
SS-SW 16 5/17/2011 <0.125 <0.125 14.7 51.6 23.6 <0.125 808 NA
SS-NW 15 5/17/2011 <0.125 <0.125 5.92 15.3 16.7 <0.125 555 NA
SS-NE 17 5/17/2011 3.67 129 67.8 376 28.3 <0.125 3,270 NA
SS-P1 3 5/19/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SS-P2 3 5/19/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SS-P3 3 5/19/2011 <0.001 0.002 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SS-P4 3 5/19/2011 <0.001 0.002 <0.001 <0.003 <0.002 <0.001 <0.05 NA
Overex - S 18 5/19/2011 <0.25 1.42 8.27 68.6 12.4 <0.25 406 NA
Overex - B 22 5/19/2011 4.83 184 76.5 529 36.6 <2.5 4,350 NA
Overex - N 18 5/19/2011 7.75 340 98.9 688 41.4 <2.5 5,580 NA
Overex - W 18 5/19/2011 12.8 488 156 1090 62.6 <12.5 7,690 NA
Overex - E 18 5/19/2011 25.8 680 213 1440 69 <12.5 9,870 NA
SB-1, 34' 34 10/13/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SB-2, 25' 25 10/13/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SB-2, 28' 28 10/13/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SB-3, 25' 25 10/13/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
SB-4, 24' 24 10/13/2011 <0.001 <0.001 <0.001 <0.003 <0.002 <0.001 <0.05 NA
*B-101. 18-19' 18-19 7/11/2024 <0.13 <0.32 5.15 12.2 4.89 <0.19 324 3,840
*B-101, 30' 30 7/11/2024 1.37 101 62.3 608 23.9 <0.21 2,080 815
*B-101, 50' 50 7/11/2024 <0.009 <0.02 <0.02 <0.07 <0.02 <0.01 <0.227 <50
0.2 9 5 142 51 0.3 150 500
0.9 25 23 142 51 0.3 1,500 5,000
MBTEXN and Total Petroleum Hydrocarbons - Gasoline Range Organics (TPH-GRO) analyzed by EPA Method 8260b
TPH-DRO = Total Petroleum Hydrocarbons - Diesel Range Organics Analyzed by EPA Method 8015b
mg/kg = milligrams per kilogram, which approximates parts per million.
Gray-shaded cells indicate concentrations that exceed Tier 1 levels.
*B101 is adjacent to the "Overex-E" sample
RBCA Tier 1 Screening Level
Table 1
Holiday Oil #30 (UST Facility No. 4001380, Release No. EMTY)
Initial Screening Level
3215 W 5400 South, Taylorsville, Utah
Soil Analytical Results
Additional Soil Sampling
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
Rockwell Solutions, Inc
Attn: Dave Hansen
718 East Bridger Lane
Elk Ridge, UT 84651
Work Order: 24G0980
Project: Holiday Oil #30
7/18/2024
Approved By:
Mark Broadhead, 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 6
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
Rockwell Solutions, Inc
Dave Hansen
718 East Bridger Lane
Elk Ridge, UT 84651
PO#:
Receipt:
Date Reported:
Project Name:
7/11/24 14:24 @ 7.9 °C
7/18/2024
Holiday Oil #30
Sample ID: B-101, 18-19'
Lab ID: 24G0980-01Matrix: Solid
Flag(s)Units
Analysis
Date/Time
Date Sampled: 7/11/24 9:55
Preparation
Date/Time
Sampled By: David Hansen
Minimum
Reporting
Limit MethodResult
Inorganic
%7/12/247/12/240.1 CTF800077.2Total Solids
MBTEXn
mg/kg dry 7/12/247/12/240.13 EPA 8260D/5030BNDBenzene
mg/kg dry 7/12/247/12/240.32 EPA 8260D/5030B5.15Ethylbenzene
mg/kg dry 7/12/247/12/240.19 EPA 8260D/5030BNDMethyl tert-Butyl Ether (MTBE)
mg/kg dry 7/12/247/12/240.32 EPA 8260D/5030B4.89Naphthalene
mg/kg dry 7/12/247/12/240.32 EPA 8260D/5030BNDToluene
mg/kg dry 7/12/247/12/240.97 EPA 8260D/5030B12.2Xylenes, total
Gasoline Range
mg/kg dry 7/12/247/12/243.24 EPA 8260B/C 5035A/[CALC]324Gasoline Range Organics
Diesel Range
mg/kg dry 7/12/247/12/2465EPA 8015 C3840Diesel Range Organics
Project Name: Holiday Oil #30 CtF WO#: 24G0980
www.ChemtechFord.com
Page 2 of 6Page 2 of 6
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
Rockwell Solutions, Inc
Dave Hansen
718 East Bridger Lane
Elk Ridge, UT 84651
PO#:
Receipt:
Date Reported:
Project Name:
7/11/24 14:24 @ 7.9 °C
7/18/2024
Holiday Oil #30
Sample ID: B-101, 30'
Lab ID: 24G0980-02Matrix: Solid
Flag(s)Units
Analysis
Date/Time
Date Sampled: 7/11/24 10:15
Preparation
Date/Time
Sampled By: David Hansen
Minimum
Reporting
Limit MethodResult
Inorganic
%7/12/247/12/240.1 CTF800072.5Total Solids
MBTEXn
mg/kg dry 7/12/247/12/240.14 EPA 8260D/5030B1.37Benzene
mg/kg dry 7/12/247/12/246.90 EPA 8260D/5030B62.3Ethylbenzene
mg/kg dry 7/12/247/12/240.21 EPA 8260D/5030BNDMethyl tert-Butyl Ether (MTBE)
mg/kg dry 7/12/247/12/240.34 EPA 8260D/5030B23.9Naphthalene
mg/kg dry 7/12/247/12/246.90 EPA 8260D/5030B101Toluene
mg/kg dry 7/12/247/12/2420.7 EPA 8260D/5030B608Xylenes, total
Gasoline Range
mg/kg dry 7/12/247/12/2420.7 EPA 8260B/C 5035A/[CALC]2080Gasoline Range Organics
Diesel Range
mg/kg dry 7/12/247/12/2469EPA 8015 C815Diesel Range Organics
Project Name: Holiday Oil #30 CtF WO#: 24G0980
www.ChemtechFord.com
Page 3 of 6Page 3 of 6
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
Rockwell Solutions, Inc
Dave Hansen
718 East Bridger Lane
Elk Ridge, UT 84651
PO#:
Receipt:
Date Reported:
Project Name:
7/11/24 14:24 @ 7.9 °C
7/18/2024
Holiday Oil #30
Sample ID: B-101, 50'
Lab ID: 24G0980-03Matrix: Solid
Flag(s)Units
Analysis
Date/Time
Date Sampled: 7/11/24 11:35
Preparation
Date/Time
Sampled By: David Hansen
Minimum
Reporting
Limit MethodResult
Inorganic
%7/12/247/12/240.1 CTF800098.2Total Solids
MBTEXn
mg/kg dry 7/12/247/12/240.009 EPA 8260D/5030BNDBenzene
mg/kg dry 7/12/247/12/240.02 EPA 8260D/5030BNDEthylbenzene
mg/kg dry 7/12/247/12/240.01 EPA 8260D/5030BNDMethyl tert-Butyl Ether (MTBE)
mg/kg dry 7/12/247/12/240.02 EPA 8260D/5030BNDNaphthalene
mg/kg dry 7/12/247/12/240.02 EPA 8260D/5030BNDToluene
mg/kg dry 7/12/247/12/240.07 EPA 8260D/5030BNDXylenes, total
Gasoline Range
mg/kg dry 7/12/247/12/240.227 EPA 8260B/C 5035A/[CALC]NDGasoline Range Organics
Diesel Range
mg/kg dry 7/12/247/12/2450EPA 8015 CNDDiesel Range Organics
Project Name: Holiday Oil #30 CtF WO#: 24G0980
www.ChemtechFord.com
Page 4 of 6Page 4 of 6
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
Rockwell Solutions, Inc
Dave Hansen
718 East Bridger Lane
Elk Ridge, UT 84651
PO#:
Receipt:
Date Reported:
Project Name:
7/11/24 14:24 @ 7.9 °C
7/18/2024
Holiday Oil #30
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: Holiday Oil #30 CtF WO#: 24G0980
www.ChemtechFord.com
Page 5 of 6Page 5 of 6
Page 6 of 6
BORING LOG
HOLE NO.
DRILLING METHOD ____________________________________________
DRILLER / COMPANY ___________________________________________ TOTAL DEPTH ____________ WATER DEPTH _______
BORING DIAMETER _________ CASING DIAMETER _________ CASING MATERIAL ____________ SLOT SIZE __________
SURFACE ELEV. ____________ TOP OF CASING ELEV. ___________ LOGGED BY _____________________________________________
DATE ___________________
EP
(
FT
D
TH

.)
E
SAMPL
S
BLOWS ON
S PLAMER
SAMPLE
R
INTE
VAL
e
(fe
t)DESCRIPTION / SOIL CLASSIFICATION
GRAPHIC LOG
AND
WELL CONSTRUCTION DEPTH
PID
Direct Push
NA David Hansen
0
Concrete
BORING LOG
HOLE NO.
DRILLING METHOD ____________________________________________
DRILLER / COMPANY ___________________________________________ TOTAL DEPTH ____________ WATER DEPTH _______
BORING DIAMETER _________ CASING DIAMETER _________ CASING MATERIAL ____________ SLOT SIZE __________
SURFACE ELEV. ____________ TOP OF CASING ELEV. ___________ LOGGED BY _____________________________________________
DATE ___________________
EP
(
FT
D
TH

.)
E
SAMPL
S
BLOWS ON
S PLAMER
SAMPLE
R
INTE
VAL
e
(fe
t)DESCRIPTION / SOIL CLASSIFICATION
GRAPHIC LOG
AND
WELL CONSTRUCTION DEPTH
PID
B-101
Refusal. End of Boring at 50 feet
NA David Hansen
0-5
Jaret, Direct Push
7/11/24
50’
2”
LOCATION ___________________________________
PROJECT ________________________________Holiday Oil #30
3215 W 5400 So, Taylorsville
0
10
20
30
40
50
Silt (ML), low plasticity, tan, damp
Sand (SW), fine to medium-grained, tan, damp
Silt (ML), low plasticity, tan, damp
Sand (SW), fine to medium-grained, tan, damp
Stained black from 18-19’625
814
390
62
5-10
10-15
15-20
20-25
0
10
20
30
40
50
Silt (ML), low plasticity, tan, damp
Sand (SW), fine to medium-grained, tan, damp
0
0
717
700
302
149