HomeMy WebLinkAboutDERR-2024-004622
Stantec Consulting Services Inc.
2890 East Cottonwood Parkway
Suite 300
Salt Lake City UT 84121-7283
February 28, 2024
Project/File: 203721718
Hong Lei-Tao
Utah Department of Environmental Quality
Division of Environmental Response and Remediation
195 North 1950 West, 1st Floor
P.O. Box 144840
Reference: Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
Dear Hong Lei-Tao,
This report presents the results of the first semiannual groundwater monitoring event conducted by Stantec
Consulting Services Inc. (Stantec) at 7-Eleven Inc. (7-Eleven) Store No. 25791 (the Site) located at 4110
South Redwood Road, Taylorsville, Utah (Figure 1) according to Work Plan and Budget (WP&B) NVQ-5.
The Utah Department of Environmental Quality (UDEQ), Division of Environmental Response and
Remediation (DERR) refers to the Site as Facility ID 4001018, Release Site NVQ. The objectives of
semiannual groundwater monitoring are to evaluate current dissolved petroleum hydrocarbon
concentrations in Site groundwater following source area soil and groundwater removal under the 2022
Corrective Action Plan (CAP).
BACKGROUND
7-Eleven operated the Site as a convenience store with retail sale of gasoline fuel beginning in January
1985. The underground storage tank (UST) system consisted of three 10,000-gallon, single-wall steel
USTs (which stored various grades of unleaded gasoline), associated product piping, and two product
dispensers. The UST system was installed in April 1984 and was removed on April 26, 2022.
Release Site NVQ was opened based on soil analytical results from a baseline environmental site
assessment conducted on October 8, 2019 above the Initial Screening Levels (ISLs) and Tier 1 Screening
Levels (TSLs) established by the Petroleum Storage Tank Branch of the UDEQ-DERR. In correspondence
dated November 20, 2019, DERR requested a subsurface investigation to characterize the release and
define the extent and degree of petroleum hydrocarbon impacts in soil and groundwater.
Stantec conducted the subsurface investigation between March 11 and March 12, 2020 and installed
groundwater monitoring wells MW-1 through MW-7. Groundwater samples were subsequently collected
from all wells on March 19, 2020. Soil and groundwater analytical results from the subsurface investigation
were reported to the UDEQ-DERR in Stantec’s Subsurface Investigation Report, 7-Eleven Store No. 25791
dated April 29, 2020. Soil and groundwater east of the UST basin and dispensers were impacted with
petroleum hydrocarbon concentrations above ISLs and TSLs. Source area soils collected from soil borings
contained evidence of petroleum hydrocarbon impacts between 12 and 14 feet (ft) below ground surface
(bgs). A silty clay layer was encountered across the Site which began at approximate depths between 12
February 28, 2024
Page 2 of 5
Reference: Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
and 16.5 ft bgs and was between 1.5 and 7 ft thick, which likely limited the downward migration of petroleum
hydrocarbons.
Stantec conducted quarterly groundwater monitoring and sampling events between September 2020 and
August 2021. As of the August 2021 groundwater monitoring event, petroleum hydrocarbon concentrations
remained above TSLs for benzene, toluene, and total petroleum hydrocarbons, gasoline range organics
(TPH-GRO) in MW-2 and MW-3. Petroleum hydrocarbon concentrations also remained above the ISL for
benzene in MW-4 and MW-5. On September 22, 2021, DERR requested off-site subsurface investigation
and groundwater monitoring well installation and one groundwater sampling event.
On January 18, 2022, 7-Eleven requested that Stantec prepare for a complete UST system removal at the
Site scheduled to begin on April 25, 2022. A CAP meeting was held on February 18, 2022 with Stantec
and UDEQ-DERR representatives in attendance. The UDEQ-DERR approved remedial excavation, soil
disposal, and groundwater removal and disposal as the CAP for the Site. Stantec prepared a CAP WP&B
NVQ-4, and CAP activities began on April 27, 2022 following removal of the UST system.
The final depth of the remedial excavation was 14 ft bgs; this was consistent with previous findings that the
maximum depth of soil impacts observed during the March 2020 subsurface investigation was 14 ft bgs.
All confirmation samples collected from the excavation bottom were below ISLs. Only one excavation side-
wall sample (SW-5) had petroleum hydrocarbon concentrations above UDEQ-DERR screening levels
(benzene above the TSL and ethylbenzene and TPH-GRO above the respective ISLs). The benzene and
TPH-GRO concentrations reported in groundwater sample GW-1 exceeded the respective ISLs.
The final lateral extent of the remedial excavation is shown on Figure 1. Stantec planned to remove
groundwater monitoring wells MW-2 and MW-3 as these wells fell within the original planned footprint of
the remedial excavation. Based on field screening results, the remedial excavation was expanded such
that removal of MW-1 was also necessary in order to remove as much petroleum impacted soil as possible
without threatening on-site infrastructure or buried utilities.
Based on the soil confirmation sample analytical results, the majority of petroleum hydrocarbon impacted
soils were removed from the Site by excavation between April 27 and May 19, 2022. A total of 3,273 tons
of impacted soil was hauled to the ET Technologies Soil Regeneration Site in Salt Lake City, Utah. A total
of 8,385 gallons of petroleum hydrocarbon impacted groundwater was hauled off-site by Sump and Trap
Cleaning of Salt Lake City, Utah for treatment and disposal.
The following Stantec reports document environmental work conducted for Release Site NVQ:
Subsurface Investigation Report, 7-Eleven Store No. 25791, dated April 29, 2020
Quarterly Groundwater Monitoring Report, 7-Eleven Store No. 25791, dated November 30, 2020
Quarterly Groundwater Monitoring Report, 7-Eleven Store No. 25791, dated February 11, 2021
Quarterly Groundwater Monitoring Report, 7-Eleven Store No. 25791, dated May 12, 2021
Corrective Action Plan Meeting Summary Letter for 7-Eleven Store No. 25791, dated March 17,
2022
Public Notification Summary for Corrective Action at 7-Eleven Store No. 25791, dated May 24,
2022
Corrective Action Report, 7-Eleven Store No. 25791, dated June 30, 2022
Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791, dated August 30, 2023
February 28, 2024
Page 3 of 5
Reference: Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
GROUNDWATER MONITORING METHODS
On December 19, 2023, Stantec conducted the second semiannual groundwater monitoring event under
WP&B NVQ-5. Monitoring wells MW-5, MW-6, and MW-7 were monitored for static water levels and
sampled.
Static water levels were recorded to the nearest one hundredth of a foot using a battery-powered
product/water interface probe. Light non-aqueous phase liquid (LNAPL) was not encountered in any of the
monitoring wells. Monitoring wells MW-5, MW-6, and MW-7 were purged until three well volumes were
removed (or until purged dry). Well purging and sampling was completed using weighted, plastic,
disposable bailers. Groundwater samples were decanted into three 40-milliliter (mL) amber glass vials;
labeled with the sample identification, collection date, and time; and placed into a chilled cooler for delivery
under chain-of-custody (COC) documentation to Pace Analytical National (Pace) of Mount Juliet,
Tennessee for analysis. Analysis included methyl tertiary butyl ether (MTBE), benzene, ethylbenzene,
toluene, total xylenes, and naphthalene (MBTEXN) and TPH-GRO by EPA Method 8260B. Two quality
assurance / quality control (QAQC) samples were also submitted for analysis: a field duplicate sample that
was collected from MW-5, and a trip blank that was prepared by Pace and traveled with the sample
containers during shipment and sample collection.
GROUNDWATER MONITORING RESULTS
Shallow groundwater beneath the Site was measured at depths ranging from 12.12 ft (MW-6) to 12.44 ft
(MW-7) below top-of-casing on December 19, 2023. Each depth to groundwater measurement was
converted to a relative groundwater elevation using the relative top-of-casing elevation of the monitoring
well. A groundwater elevation contour map is provided on Figure 2. Groundwater analytical results for this
investigation are summarized in Table 1. Laboratory analytical reports and chain-of-custody
documentation are included in Appendix A.
Field and analytical results for groundwater sampling during this monitoring event indicate the following:
Shallow groundwater beneath the Site appears to flow in a northeasterly direction at a local hydraulic
gradient of approximately 0.008 feet per foot as measured between MW-7 and a central point between
MW-5 and MW-6;
All dissolved petroleum hydrocarbon concentrations were either below ISLs or were not detected above
the laboratory reporting limits.
The dissolved benzene concentration in MW-5 remains below the ISL. MW-5 dissolved benzene
concentrations were historically above the ISL prior to CAP source area soil and groundwater removal.
All dissolved petroleum hydrocarbon concentrations remained below the laboratory reporting limits in
MW-7.
All relative percent differences calculated between the parent and duplicate sample collected from
MW-5 were within generally accepted standards.
No dissolved petroleum hydrocarbon concentrations were reported above the laboratory reporting limits
in the trip blank.
February 28, 2024
Page 4 of 5
Reference: Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
CONCLUSIONS AND RECOMMENDATIONS
No dissolved petroleum hydrocarbon concentrations above ISLs were reported in Site groundwater
samples collected on June 29 and December 19, 2023. As previously noted, the removal of MW-4 during
remedial excavation created a data gap for dissolved petroleum hydrocarbon concentrations at the Site as
MW-4 was the most impacted, non-source area well prior to remedial excavation. Field observations during
remedial excavation also suggested petroleum hydrocarbon impacts extended beyond the Site property
boundary to the south. However, it appears that CAP activities removed sufficient source area soil and
groundwater such that on-site, downgradient petroleum hydrocarbon impacts have been mitigated to below
ISLs. Stantec recommends Release Site NVQ be granted regulatory closure and requests a No Further
Action (NFA) letter be issued by UDEQ-DERR.
LIMITATIONS AND CERTIFICATION
The conclusions in the Report titled Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
are Stantec’s professional opinion, as of the time of the Report, and concerning the scope described in the
Report. The opinions in the document are based on conditions and information existing at the time the
scope of work was conducted and do not take into account any subsequent changes. The Report relates
solely to the specific project for which Stantec was retained and the stated purpose for which the Report
was prepared. The Report is not to be used or relied on for any variation or extension of the project, or for
any other project or purpose, and any unauthorized use or reliance is at the recipient’s own risk.
Stantec has assumed all information received from 7-Eleven (the “Client”) and third parties in the
preparation of the Report to be correct. While Stantec has exercised a customary level of judgment or due
diligence in the use of such information, Stantec assumes no responsibility for the consequences of any
error or omission contained therein.
This Report is intended solely for use by the Client in accordance with Stantec’s contract with the Client.
While the Report may be provided by the Client to applicable authorities having jurisdiction and to other
third parties in connection with the project, Stantec disclaims any legal duty based upon warranty, reliance
or any other theory to any third party, and will not be liable to such third party for any damages or losses of
any kind that may result.
February 28, 2024
Page 5 of 5
Reference: Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
If you have any questions or require any additional information, please contact Anna Skinner via the contact
information provided below.
Sincerely,
STANTEC CONSULTING SERVICES INC.
Anna Skinner
Project Manager
Certified Consultant #CC0271
Phone: 801-743-4815
anna.skinner@stantec.com
Attachments: Figure 1 Site Plan
Figure 2 Groundwater Elevation Contour Map, December 19, 2023
Table 1 Groundwater Analytical Results
Attachment 1 Laboratory Report and Chain-of-Custody Documentation
February 28, 2024
Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
FIGURES
203721718 STA AS AS 08/25/23
1SITE PLAN
FOR:
JOB NUMBER:DRAWN BY:CHECKED BY:APPROVED BY:DATE:
FIGURE:
FILEPATH:C:\Users\SAguinaldo\Desktop\2023\SLC\203721718\FIG 1_7-11_25791_SITE PLAN.dwg | Layout Tab: 1 | Drafter: SAguinaldo | Aug 25, 2023 at 13:31
7-ELEVEN #25791
4110 REDWOOD ROAD
TAYLORSVILLE, UTAH
MONITORING WELL LOCATION
LEGEND:
BASELINE ASSESSMENT PROBEHOLE LOCATION
0 30 60
APPROXIMATE SCALE IN FEET
N
COMMERCIAL
PROPERTY
PHONE:
2890 E COTTONWOOD PKWY, STE 300
SALT LAKE CITY, UTAH
(801) 261-0090
CONVENIENCE
STORE
BUILDING
4100 SOUTH STREET
MW-6
MW-5
PH-2
PH-1
RE
D
W
O
O
D
R
O
A
D
COMMERCIAL
PROPERTY
DESTROYED MONITORING WELL LOCATION
MW-1
EXCAVATION EXTENT
MW-7
PH-3
MW-2
MW-3
MW-4
203721718 STA AS JPW 02/24/24
2GROUNDWATER ELEVATION
CONTOUR MAP
DECEMBER 19, 2023
FOR:
JOB NUMBER:DRAWN BY:CHECKED BY:APPROVED BY:DATE:
FIGURE:
FILEPATH:C:\Users\SAguinaldo\Desktop\2024\SLC\203721718\4Q 2023\FIG 1_7-11_25791_SITE PLAN.dwg | Layout Tab: 2 | Drafter: SAguinaldo | Feb 23, 2024 at 15:16
7-ELEVEN #25791
4110 REDWOOD ROAD
TAYLORSVILLE, UTAH
LEGEND:
0 30 60
APPROXIMATE SCALE IN FEET
N
COMMERCIAL
PROPERTY
PHONE:
2890 E COTTONWOOD PKWY, STE 300
SALT LAKE CITY, UTAH
(801) 261-0090
87.51
88.00
EXCAVATION EXTENT
DESTROYED MONITORING WELL LOCATION
BASELINE ASSESSMENT PROBEHOLE LOCATION
MONITORING WELL LOCATION
GROUNDWATER SURFACE ELEVATION
(FEET ABOVE MEAN SEA LEVEL)
GROUNDWATER ELEVATION CONTOUR
(DASHED WHERE INFERRED)
CONVENIENCE
STORE
BUILDING
4100 SOUTH STREET
MW-6
PH-2
PH-1
RE
D
W
O
O
D
R
O
A
D
COMMERCIAL
PROPERTY
MW-1
MW-7
PH-3
MW-2
MW-3
MW-4
87.38
88.15
8
7
.
7
5
8
7
.
5
0
88
.
0
0
8
8
.
0
0
8
7
.
7
5
MW-5
87.51
87.
5
0
February 28, 2024
Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
TABLES
MTBE Benzene Toluene Ethylbenzene Total Xylenes
Baseline Investigation Results
PH-1 10/08/19 -- --<0.400 6.84 <0.200 2.65 4.14 0.607 36.8
PH-2 10/08/19 -- --<0.500 7.24 11.0 1.70 10.2 0.306 62.0
PH-3 10/08/19 -- -- <0.00200 0.0346 0.00157 0.00147 0.00272 <0.00100 2.18
Additional Subsurface Investigation and Quarterly Monitoring Results
03/19/20 11.85 88.15 <0.00200 <0.00100 <0.00100 <0.00100 <0.00100 <0.00100 <0.0500
11/05/20 11.94 88.06 <0.000500 0.00201 0.000524 <0.000500 0.000532 <0.00100 <0.0500
01/21/21 12.55 87.45 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
04/27/21 11.82 88.18 <0.000500 0.000725 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
08/02/21 11.65 88.35 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
06/29/23
03/19/20 12.37 87.97 <0.0400 0.371 0.960 0.174 1.27 0.0450 5.71
11/05/20 12.44 87.90 <0.0500 1.26 2.35 0.362 1.96 <0.100 11.9
01/21/21 13.10 87.24 <0.0100 0.456 0.449 0.166 0.601 0.0465 4.34
04/27/21 12.00 88.34 <0.00200 0.253 0.287 0.0863 0.304 0.0316 1.84
08/02/21 12.27 88.07 <0.0500 1.68 3.50 0.334 2.02 <0.100 15.4
06/29/23
03/19/20 11.95 87.68 <0.00800 0.196 0.0447 0.0309 0.194 0.0125 1.14
11/05/20 12.00 87.63 <0.0100 0.480 <0.0100 0.107 0.181 <0.0200 1.07
01/21/21 12.59 87.04 <0.00100 0.0670 <0.00100 0.0113 0.00125 <0.00200 0.241
04/27/21 12.54 87.09 <0.00200 0.230 0.0122 0.0466 0.0575 0.0100 0.857
08/02/21 11.74 87.89 <0.00500 0.319 0.00893 0.0765 0.111 0.0186 1.14
06/29/23
03/19/20 12.08 87.69 <0.00400 0.0418 0.0251 0.0212 0.150 0.0121 0.752
11/05/20 12.21 87.56 <0.000500 0.0297 0.00214 <0.000500 0.120 0.00242 0.228
01/21/21 12.75 87.02 <0.000500 0.0165 <0.000500 0.00503 <0.000500 0.00153 0.0919
04/27/21 12.24 87.53 <0.000500 0.0454 0.00265 0.00995 0.0162 0.00240 0.232
08/02/21 11.93 87.84 <0.00200 0.213 0.0190 0.0256 0.0452 0.0152 0.755
06/29/23
03/19/20 12.40 87.37 <0.00400 0.0582 0.0119 0.0221 0.0350 0.0198 0.618
11/05/20 12.47 87.30 <0.000500 0.0605 0.00184 0.0447 0.00284 0.0280 0.498
01/21/21 13.09 86.68 <0.000500 0.0204 0.000957 0.00121 0.000551 0.00303 0.154
04/27/21 12.44 87.33 <0.000500 0.0114 0.00150 0.000678 0.000549 0.00286 0.107
08/02/21 12.21 87.56 <0.00100 0.0987 0.0115 0.0598 0.00365 0.0295 0.675
06/29/23 12.06 87.71 <0.00100 0.00210 <0.00100 0.00368 <0.00300 <0.00500
C4 0.647
12/19/23 12.26 87.51 <0.00100 0.00137 <0.00100 0.0178 0.00312 <0.00500 0.609 B
03/19/20 12.20 87.30 <0.00200 <0.00100 <0.00100 <0.00100 <0.00100 <0.00100 0.194
11/05/20 12.22 87.28 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 0.00129 0.155
01/21/21 12.93 86.57 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
04/27/21 12.15 87.35 <0.000500 0.000863 <0.000500 <0.000500 <0.000500 0.00147 0.265
08/02/21 11.95 87.55 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 0.189
06/29/23 11.82 87.68 <0.00100 <0.00100 <0.00100 <0.00100 <0.00300 <0.00500
C4 0.533
12/19/23 12.12 87.38 <0.00100 <0.00100 <0.00100 <0.00100 <0.00300 <0.00500 0.615 B
03/19/20 12.33 88.26 <0.00200 <0.00100 <0.00100 <0.00100 <0.00100 <0.00100 <0.0500
11/05/20 12.47 88.12 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
01/21/21 13.10 87.49 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
04/27/21 12.55 88.04 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
08/02/21 12.24 88.35 <0.000500 <0.000500 <0.000500 <0.000500 <0.000500 <0.00100 <0.0500
06/29/23 12.10 88.49 <0.00100 <0.00100 <0.00100 <0.00100 <0.00300 <0.00500 <0.500
12/19/23 12.44 88.15 <0.00100 <0.00100 <0.00100 <0.00100 <0.00300 <0.00500 <0.500
CAP Remedial Excavation Results
GW-1 05/16/22
13 --<0.00500 0.0178 0.0333 0.0868 0.174 0.236
4.93
0.2 0.005 1.0 0.7 10 0.7 1.0
0.2 0.3 3.0 4.0 10 0.7 10
Removed during remedial excavation.
Removed during remedial excavation.
Removed during remedial excavation.
Removed during remedial excavation.
MBTEXN Compounds
(mg/L)
Naphthalene
Table 1
UDEQ DERR Tier 1 Screening Level
UDEQ DERR Initial Screening Level
Taylorsville, Utah
4110 South Redwood Road
7-Eleven Store No. 25791
Groundwater Analytical Results
Depth to
Groundwater
(feet)
Relative
Groundwater
Elevation
(feet)
TPH-GRO
(mg/L)
Sample
Location Date
MW-1
MW-7
MW-2
MW-3
MW-4
MW-6
MW-5
dbs_25791_20231219.xlsx Water 1 of 2 Stantec Consulting Services Inc.
Table 1
Taylorsville, Utah
4110 South Redwood Road
7-Eleven Store No. 25791
Groundwater Analytical Results
Well
No.
Total Well
Depth
(feet)
Screened
Interval
(feet)
Relative Top
of Casing
Elevation*
(feet)
MW-1 20 5 to 20 100.00
MW-2 20 5 to 20 100.34
MW-3 20 5 to 20 99.63
MW-4 20 5 to 20 99.77
MW-5 20 5 to 20 99.77
MW-6 20 5 to 20 99.50
MW-7 20 5 to 20 100.59
Explanation of Abbreviations
MBTEXN = methyl tertiary butyl ether, benzene, toluene, ethylbenzene, total xylenes, and naphthalene
mg/L = milligrams per liter
MTBE = methyl tertiary butyl ether
TPH-GRO = gasoline-range total petroleum hydrocarbons
UDEQ = Utah Department of Environmental Quality
DERR = Department of Environmental Response and Remediation
* = MW-1 TOC elevation assigned 100 feet and TOC of remaining wells calculated from survey data
< = analyte not detected above the laboratory specified reporting limit
bold = analyte detected above the specified laboratory reporting limit
bold = analytical result exceeds the specified UDEQ DERR Initial Screening Level
bold = analytical result exceeds the specified UDEQ DERR Initial Screening Level and Tier 1 Screening Level
C4 = The reported concentration is an estimate. The continuing calibration standard associated with this data responded low. Data
is likely to show a low bias concerning the result. Sample was re-ran (outside of holding time) with the same result.
B = The same analyte is found in the associated blank.
dbs_25791_20231219.xlsx Water 2 of 2 Stantec Consulting Services Inc.
February 28, 2024
Semiannual Groundwater Monitoring Report, 7-Eleven Store No. 25791
4110 South Redwood Road, Taylorsville, Utah
Facility ID 4001018, Release Site NVQ
ATTACHMENT 1
Laboratory Report and Chain-of-Custody Documentation
ANALYTICAL REPORT
December 29, 2023
711 Stantec - Salt Lake City, UT
Sample Delivery Group:L1689816
Samples Received:12/20/2023
Project Number:203721718
Description:7-11 #25791 Taylorsville, UT
Site:25791
Report To:Anna Skinner
2890 E Cottonwood Pkwy
Suite 300
Salt Lake City, UT 84121
Entire Report Reviewed By:
December 29, 2023
[Preliminary Report]
Marty Edwards III
Project Manager
Results relate only to the items tested or calibrated and are reported as rounded values. This test report shall not be
reproduced, except in full, without written approval of the laboratory. Where applicable, sampling conducted by Pace
Analytical National is performed per guidance provided in laboratory standard operating procedures ENV-SOP-MTJL-0067 and
ENV-SOP-MTJL-0068. Where sampling conducted by the customer, results relate to the accuracy of the information provided,
and as the samples are received.
Pace Analytical National
12065 Lebanon Rd Mount Juliet, TN 37122 615-758-5858 800-767-5859 www.pacenational.com
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE:
711 Stantec - Salt Lake City, UT 203721718 L1689816 12/29/23 10:34 1 of 13
December 29, 2023
Marty Edwards III
Project Manager
ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE:
711 Stantec - Salt Lake City, UT 203721718 L1689816 12/29/23 12:17 1 of 13
TABLE OF CONTENTS
Cp: Cover Page 1
Tc: Table of Contents 2
Ss: Sample Summary 3
Cn: Case Narrative 4
Sr: Sample Results 5
MW-5 L1689816-01 5
MW-6 L1689816-02 6
MW-7 L1689816-03 7
DUP-01 L1689816-04 8
TB-20231219 L1689816-05 9
Qc: Quality Control Summary 10
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 10
Gl: Glossary of Terms 11
Al: Accreditations & Locations 12
Sc: Sample Chain of Custody 13
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE:
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ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE:
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SAMPLE SUMMARY
Collected by Collected date/time Received date/time
MW-5 L1689816-01 GW Cody Fauth 12/19/23 11:35 12/20/23 09:00
Method Batch Dilution Preparation Analysis Analyst Location
date/time date/time
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 WG2195123 1 12/23/23 21:51 12/23/23 21:51 DWR Mt. Juliet, TN
Collected by Collected date/time Received date/time
MW-6 L1689816-02 GW Cody Fauth 12/19/23 11:30 12/20/23 09:00
Method Batch Dilution Preparation Analysis Analyst Location
date/time date/time
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 WG2195123 1 12/23/23 22:12 12/23/23 22:12 DWR Mt. Juliet, TN
Collected by Collected date/time Received date/time
MW-7 L1689816-03 GW Cody Fauth 12/19/23 11:25 12/20/23 09:00
Method Batch Dilution Preparation Analysis Analyst Location
date/time date/time
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 WG2195123 1 12/23/23 22:33 12/23/23 22:33 DWR Mt. Juliet, TN
Collected by Collected date/time Received date/time
DUP-01 L1689816-04 GW Cody Fauth 12/19/23 00:00 12/20/23 09:00
Method Batch Dilution Preparation Analysis Analyst Location
date/time date/time
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 WG2195123 1 12/23/23 22:54 12/23/23 22:54 DWR Mt. Juliet, TN
Collected by Collected date/time Received date/time
TB-20231219 L1689816-05 GW Cody Fauth 12/19/23 00:00 12/20/23 09:00
Method Batch Dilution Preparation Analysis Analyst Location
date/time date/time
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 WG2195123 1 12/23/23 21:08 12/23/23 21:08 DWR Mt. Juliet, TN
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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CASE NARRATIVE
All sample aliquots were received at the correct temperature, in the proper containers, with the
appropriate preservatives, and within method specified holding times, unless qualified or notated within
the report. Where applicable, all MDL (LOD) and RDL (LOQ) values reported for environmental samples
have been corrected for the dilution factor used in the analysis. All Method and Batch Quality Control
are within established criteria except where addressed in this case narrative, a non-conformance form
or properly qualified within the sample results. By my digital signature below, I affirm to the best of my
knowledge, all problems/anomalies observed by the laboratory as having the potential to affect the
quality of the data have been identified by the laboratory, and no information or data have been
knowingly withheld that would affect the quality of the data.
[Preliminary Report]
Marty Edwards III
Project Manager
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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Marty Edwards III
Project Manager
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SAMPLE RESULTS - 01
L1689816
MW-5
Collected date/time: 12/19/23 11:35
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1
Result Qualifier RDL Dilution Analysis Batch
Analyte mg/l mg/l date / time
TPH (GC/MS) Low Fraction 0.609 B 0.500 1 12/23/2023 21:51 WG2195123
Benzene 0.00137 0.00100 1 12/23/2023 21:51 WG2195123
Ethylbenzene 0.0178 0.00100 1 12/23/2023 21:51 WG2195123
Methyl tert-butyl ether ND 0.00100 1 12/23/2023 21:51 WG2195123
Naphthalene ND 0.00500 1 12/23/2023 21:51 WG2195123
Toluene ND 0.00100 1 12/23/2023 21:51 WG2195123
Xylenes, Total 0.00312 0.00300 1 12/23/2023 21:51 WG2195123
(S) Toluene-d8 110 80.0-120 12/23/2023 21:51 WG2195123
(S) 4-Bromofluorobenzene 99.4 77.0-126 12/23/2023 21:51 WG2195123
(S) 1,2-Dichloroethane-d4 90.8 70.0-130 12/23/2023 21:51 WG2195123
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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SAMPLE RESULTS - 02
L1689816
MW-6
Collected date/time: 12/19/23 11:30
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1
Result Qualifier RDL Dilution Analysis Batch
Analyte mg/l mg/l date / time
TPH (GC/MS) Low Fraction 0.615 B 0.500 1 12/23/2023 22:12 WG2195123
Benzene ND 0.00100 1 12/23/2023 22:12 WG2195123
Ethylbenzene ND 0.00100 1 12/23/2023 22:12 WG2195123
Methyl tert-butyl ether ND 0.00100 1 12/23/2023 22:12 WG2195123
Naphthalene ND 0.00500 1 12/23/2023 22:12 WG2195123
Toluene ND 0.00100 1 12/23/2023 22:12 WG2195123
Xylenes, Total ND 0.00300 1 12/23/2023 22:12 WG2195123
(S) Toluene-d8 118 80.0-120 12/23/2023 22:12 WG2195123
(S) 4-Bromofluorobenzene 101 77.0-126 12/23/2023 22:12 WG2195123
(S) 1,2-Dichloroethane-d4 95.6 70.0-130 12/23/2023 22:12 WG2195123
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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SAMPLE RESULTS - 03
L1689816
MW-7
Collected date/time: 12/19/23 11:25
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1
Result Qualifier RDL Dilution Analysis Batch
Analyte mg/l mg/l date / time
TPH (GC/MS) Low Fraction ND 0.500 1 12/23/2023 22:33 WG2195123
Benzene ND 0.00100 1 12/23/2023 22:33 WG2195123
Ethylbenzene ND 0.00100 1 12/23/2023 22:33 WG2195123
Methyl tert-butyl ether ND 0.00100 1 12/23/2023 22:33 WG2195123
Naphthalene ND 0.00500 1 12/23/2023 22:33 WG2195123
Toluene ND 0.00100 1 12/23/2023 22:33 WG2195123
Xylenes, Total ND 0.00300 1 12/23/2023 22:33 WG2195123
(S) Toluene-d8 113 80.0-120 12/23/2023 22:33 WG2195123
(S) 4-Bromofluorobenzene 96.1 77.0-126 12/23/2023 22:33 WG2195123
(S) 1,2-Dichloroethane-d4 94.6 70.0-130 12/23/2023 22:33 WG2195123
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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SAMPLE RESULTS - 04
L1689816
DUP-01
Collected date/time: 12/19/23 00:00
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1
Result Qualifier RDL Dilution Analysis Batch
Analyte mg/l mg/l date / time
TPH (GC/MS) Low Fraction 0.627 B 0.500 1 12/23/2023 22:54 WG2195123
Benzene 0.00153 0.00100 1 12/23/2023 22:54 WG2195123
Ethylbenzene 0.0202 0.00100 1 12/23/2023 22:54 WG2195123
Methyl tert-butyl ether ND 0.00100 1 12/23/2023 22:54 WG2195123
Naphthalene 0.00516 0.00500 1 12/23/2023 22:54 WG2195123
Toluene ND 0.00100 1 12/23/2023 22:54 WG2195123
Xylenes, Total 0.00356 0.00300 1 12/23/2023 22:54 WG2195123
(S) Toluene-d8 114 80.0-120 12/23/2023 22:54 WG2195123
(S) 4-Bromofluorobenzene 98.9 77.0-126 12/23/2023 22:54 WG2195123
(S) 1,2-Dichloroethane-d4 93.4 70.0-130 12/23/2023 22:54 WG2195123
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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SAMPLE RESULTS - 05
L1689816
TB-20231219
Collected date/time: 12/19/23 00:00
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1
Result Qualifier RDL Dilution Analysis Batch
Analyte mg/l mg/l date / time
TPH (GC/MS) Low Fraction ND 0.500 1 12/23/2023 21:08 WG2195123
Benzene ND 0.00100 1 12/23/2023 21:08 WG2195123
Ethylbenzene ND 0.00100 1 12/23/2023 21:08 WG2195123
Methyl tert-butyl ether ND 0.00100 1 12/23/2023 21:08 WG2195123
Naphthalene ND 0.00500 1 12/23/2023 21:08 WG2195123
Toluene ND 0.00100 1 12/23/2023 21:08 WG2195123
Xylenes, Total ND 0.00300 1 12/23/2023 21:08 WG2195123
(S) Toluene-d8 115 80.0-120 12/23/2023 21:08 WG2195123
(S) 4-Bromofluorobenzene 98.4 77.0-126 12/23/2023 21:08 WG2195123
(S) 1,2-Dichloroethane-d4 93.8 70.0-130 12/23/2023 21:08 WG2195123
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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QUALITY CONTROL SUMMARYWG2195123
Volatile Organic Compounds (GC/MS) by Method 8260B/8260B/OA1 L1689816-01,02,03,04,05
Method Blank (MB)
(MB) R4017594-4 12/23/23 20:08
MB Result MB Qualifier MB MDL MB RDL
Analyte mg/l mg/l mg/l
TPH (GC/MS) Low Fraction 0.305 J 0.108 0.500
Benzene U 0.0000941 0.00100
Ethylbenzene U 0.000137 0.00100
Methyl tert-butyl ether U 0.000101 0.00100
Naphthalene U 0.00100 0.00500
Toluene U 0.000278 0.00100
Xylenes, Total U 0.000174 0.00300
(S) Toluene-d8 114 80.0-120
(S) 4-Bromofluorobenzene 97.6 77.0-126
(S) 1,2-Dichloroethane-d4 95.9 70.0-130
Laboratory Control Sample (LCS) • Laboratory Control Sample Duplicate (LCSD)
(LCS) R4017594-1 12/23/23 17:52 • (LCSD) R4017594-3 12/23/23 18:55
Spike Amount LCS Result LCSD Result LCS Rec.LCSD Rec.Rec. Limits LCS Qualifier LCSD Qualifier RPD RPD Limits
Analyte mg/l mg/l mg/l %%%%%
Benzene 0.00500 0.00509 0.00491 102 98.2 70.0-123 3.60 20
Ethylbenzene 0.00500 0.00582 0.00549 116 110 79.0-123 5.84 20
Methyl tert-butyl ether 0.00500 0.00449 0.00451 89.8 90.2 68.0-125 0.444 20
Naphthalene 0.00500 0.00485 0.00530 97.0 106 54.0-135 8.87 20
Toluene 0.00500 0.00588 0.00552 118 110 79.0-120 6.32 20
Xylenes, Total 0.0150 0.0172 0.0164 115 109 79.0-123 4.76 20
(S) Toluene-d8 114 109 80.0-120
(S) 4-Bromofluorobenzene 101 99.2 77.0-126
(S) 1,2-Dichloroethane-d4 97.6 97.2 70.0-130
Laboratory Control Sample (LCS)
(LCS) R4017594-2 12/23/23 18:34
Spike Amount LCS Result LCS Rec.Rec. Limits LCS Qualifier
Analyte mg/l mg/l %%
TPH (GC/MS) Low Fraction 5.00 4.66 93.2 66.0-132
(S) Toluene-d8 107 80.0-120
(S) 4-Bromofluorobenzene 113 77.0-126
(S) 1,2-Dichloroethane-d4 106 70.0-130
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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GLOSSARY OF TERMS
Guide to Reading and Understanding Your Laboratory Report
The information below is designed to better explain the various terms used in your report of analytical results from the Laboratory. This is not
intended as a comprehensive explanation, and if you have additional questions please contact your project representative.
Results Disclaimer - Information that may be provided by the customer, and contained within this report, include Permit Limits, Project Name,
Sample ID, Sample Matrix, Sample Preservation, Field Blanks, Field Spikes, Field Duplicates, On-Site Data, Sampling Collection Dates/Times, and
Sampling Location. Results relate to the accuracy of this information provided, and as the samples are received.
Abbreviations and Definitions
MDL Method Detection Limit.
ND Not detected at the Reporting Limit (or MDL where applicable).
RDL Reported Detection Limit.
Rec.Recovery.
RPD Relative Percent Difference.
SDG Sample Delivery Group.
(S)
Surrogate (Surrogate Standard) - Analytes added to every blank, sample, Laboratory Control Sample/Duplicate and
Matrix Spike/Duplicate; used to evaluate analytical efficiency by measuring recovery. Surrogates are not expected to be
detected in all environmental media.
U Not detected at the Reporting Limit (or MDL where applicable).
Analyte The name of the particular compound or analysis performed. Some Analyses and Methods will have multiple analytes
reported.
Dilution
If the sample matrix contains an interfering material, the sample preparation volume or weight values differ from the
standard, or if concentrations of analytes in the sample are higher than the highest limit of concentration that the
laboratory can accurately report, the sample may be diluted for analysis. If a value different than 1 is used in this field, the
result reported has already been corrected for this factor.
Limits
These are the target % recovery ranges or % difference value that the laboratory has historically determined as normal
for the method and analyte being reported. Successful QC Sample analysis will target all analytes recovered or
duplicated within these ranges.
Qualifier
This column provides a letter and/or number designation that corresponds to additional information concerning the result
reported. If a Qualifier is present, a definition per Qualifier is provided within the Glossary and Definitions page and
potentially a discussion of possible implications of the Qualifier in the Case Narrative if applicable.
Result
The actual analytical final result (corrected for any sample specific characteristics) reported for your sample. If there was
no measurable result returned for a specific analyte, the result in this column may state “ND” (Not Detected) or “BDL”
(Below Detectable Levels). The information in the results column should always be accompanied by either an MDL
(Method Detection Limit) or RDL (Reporting Detection Limit) that defines the lowest value that the laboratory could detect
or report for this analyte.
Uncertainty
(Radiochemistry)Confidence level of 2 sigma.
Case Narrative (Cn)
A brief discussion about the included sample results, including a discussion of any non-conformances to protocol
observed either at sample receipt by the laboratory from the field or during the analytical process. If present, there will
be a section in the Case Narrative to discuss the meaning of any data qualifiers used in the report.
Quality Control
Summary (Qc)
This section of the report includes the results of the laboratory quality control analyses required by procedure or
analytical methods to assist in evaluating the validity of the results reported for your samples. These analyses are not
being performed on your samples typically, but on laboratory generated material.
Sample Chain of
Custody (Sc)
This is the document created in the field when your samples were initially collected. This is used to verify the time and
date of collection, the person collecting the samples, and the analyses that the laboratory is requested to perform. This
chain of custody also documents all persons (excluding commercial shippers) that have had control or possession of the
samples from the time of collection until delivery to the laboratory for analysis.
Sample Results (Sr)
This section of your report will provide the results of all testing performed on your samples. These results are provided
by sample ID and are separated by the analyses performed on each sample. The header line of each analysis section for
each sample will provide the name and method number for the analysis reported.
Sample Summary (Ss)This section of the Analytical Report defines the specific analyses performed for each sample ID, including the dates and
times of preparation and/or analysis.
Qualifier Description
B The same analyte is found in the associated blank.
J The identification of the analyte is acceptable; the reported value is an estimate.
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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Pace Analytical National 12065 Lebanon Rd Mount Juliet, TN 37122
Alabama 40660 Nebraska NE-OS-15-05
Alaska 17-026 Nevada TN000032021-1
Arizona AZ0612 New Hampshire 2975
Arkansas 88-0469 New Jersey–NELAP TN002
California 2932 New Mexico ¹TN00003
Colorado TN00003 New York 11742
Connecticut PH-0197 North Carolina Env375
Florida E87487 North Carolina ¹DW21704
Georgia NELAP North Carolina ³41
Georgia ¹923 North Dakota R-140
Idaho TN00003 Ohio–VAP CL0069
Illinois 200008 Oklahoma 9915
Indiana C-TN-01 Oregon TN200002
Iowa 364 Pennsylvania 68-02979
Kansas E-10277 Rhode Island LAO00356
Kentucky ¹ ⁶KY90010 South Carolina 84004002
Kentucky ²16 South Dakota n/a
Louisiana AI30792 Tennessee ¹ ⁴2006
Louisiana LA018 Texas T104704245-20-18
Maine TN00003 Texas ⁵LAB0152
Maryland 324 Utah TN000032021-11
Massachusetts M-TN003 Vermont VT2006
Michigan 9958 Virginia 110033
Minnesota 047-999-395 Washington C847
Mississippi TN00003 West Virginia 233
Missouri 340 Wisconsin 998093910
Montana CERT0086 Wyoming A2LA
A2LA – ISO 17025 1461.01 AIHA-LAP,LLC EMLAP 100789
A2LA – ISO 17025 ⁵1461.02 DOD 1461.01
Canada 1461.01 USDA P330-15-00234
EPA–Crypto TN00003
ACCREDITATIONS & LOCATIONS
¹ Drinking Water ² Underground Storage Tanks ³ Aquatic Toxicity ⁴ Chemical/Microbiological ⁵ Mold ⁶ Wastewater n/a Accreditation not applicable
* Not all certifications held by the laboratory are applicable to the results reported in the attached report.
* Accreditation is only applicable to the test methods specified on each scope of accreditation held by Pace Analytical.
1 Cp
2 Tc
3 Ss
4 Cn
5 Sr
6 Qc
7 Gl
8 Al
9 Sc
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