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Cover Page
Fifth Groundwater Monitoring Report;
2025 First Semi-Annual Event
21st & 21st Properties
NEC 2100 South and 2100 East
Salt Lake City, Salt Lake County, Utah
July 10, 2025| Terracon Project No. 61197460
Prepared for:
Rockworth Companies
Holladay, Utah
6952 South High Tech Drive Ste. B
Midvale, Utah 84047
P (801) 545-8500
Terracon.com
Facilities | Environmental | Geotechnical | Materials i
Cover Letter
July 10, 2025
Rockworth Companies
4655 South 2300 East, Suite 205
Holladay, Utah 84117
Attn: Mr. Tom Henriod
P: (801)501-0727
E:tom@rockworthco.com
Re: Fifth Groundwater Monitoring Report; 2025 First Semi-Annual Event
21st & 21st Properties
NEC 2100 South and 2100 East
Salt Lake City, Salt Lake County, Utah
Terracon Project No. 61197460
Dear Mr. Henriod:
Terracon Consultants, Inc. (Terracon) is pleased to submit this Fifth Groundwater Monitoring
Report documenting the fifth groundwater sampling event conducted at the 21st and 21st
Properties, located at 2100 South and 2100 East, Salt Lake City, Utah.
Terracon has performed this work pursuant to the Remedial Action Plan (RAP; Terracon;
dated April 7, 2021) and subsequent Amendments submitted to the Utah Department of
Environmental Quality, Division of Solid Waste Management and Radiation Control (UDEQ,
DWMRC), who is the regulatory agency overseeing the cleanup of chlorinated solvents
present in the groundwater under the site. The work was also performed as part of the
cleanup of a Leaking Underground Storage Tank (LUST) facility (Facility ID 4002582,
Release Site ID NYA) present in the southwest portion of the site through the UDEQ Division
of Environmental Response and Remediation (DERR).
We appreciate the opportunity to have performed these services for you. Please contact our
office at (801) 545-8500 if you have questions regarding this information or if we can
provide any other services.
Sincerely,
Terracon Consultants, Inc.
Andrew Turner Amy Austin
Project Manager Authorized Project Reviewer
Facilities | Environmental | Geotechnical | Materials ii
Table Of Contents
1.0 Introduction ................................................................................ 1
1.1 Site Description ..................................................................................... 1
1.2 Soil Boring and Monitoring Well Installation ............................................... 2
1.3 Groundwater Elevation Survey ................................................................. 3
1.4 Scope of Services ................................................................................... 3
1.5 Standard of Care .................................................................................... 4
1.6 Additional Scope Limitations .................................................................... 4
1.7 Reliance ................................................................................................ 4
2.0 Groundwater Sampling Event ........................................................ 5
2.1 Groundwater Sample Collection ............................................................... 5
2.2 General Observations ............................................................................. 5
3.0 Laboratory Analytical Methods ....................................................... 5
4.0 Data Evaluation ........................................................................... 6
4.1 Quality Control ....................................................................................... 6
5.0 Findings And Conclusions .............................................................. 7
Facilities | Environmental | Geotechnical | Materials iii
APPENDICES
Appendix A Exhibits
Exhibit 1: Topographic Site Overview
Exhibit 2: Post Construction Monitoring Wells
Exhibit 3: Groundwater Elevation, June 2025
Exhibit 4: PCE Exceedances in Groundwater, March 2024
Exhibit 5: PCE Exceedances in Groundwater, June 2024
Exhibit 6: PCE Exceedances in Groundwater, September 2024
Exhibit 7: PCE Exceedances in Groundwater, December 2024
Exhibit 8: PCE Exceedances in Groundwater, June 2025
Appendix B Data Tables
Table 1: Well Construction and Groundwater Elevation Data
Table 2: Groundwater Analytical Results
Appendix C Monitoring Well Boring Logs
Appendix D Revised Site Management Plan Outline, February 17, 2022
Appendix E Well Development Forms
Appendix F Monitoring Well Sampling Field Notes
Appendix G Risk Evaluation Sheets
Appendix H Chain of Custody and Laboratory Data Sheets
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 1
1.0 Introduction
1.1 Site Description
The Site initially consisted of eight parcels. Numerous Phase I Environmental Site
Assessments and subsequent Limited Site Investigations were conducted at the properties
from approximately 2014 through 2019 by Terracon and others. Results of these studies
indicated there were soil and groundwater impacts from chlorinated volatile organic
compounds (VOCs) thought to have originated from on-site historical dry cleaning
businesses. In 2020, two additional parcels were added to the proposed development: the
Blue Plate Diner parcel and the 21st Coffee parcel.
Two historical dry cleaners and a historical gas station had operated at these properties,
and these former businesses were found to have contributed to the chlorinated VOC
impacts. In addition, the historical gas station was identified as a release site and was
issued an Underground Storage Tank (UST) facility ID and a Release ID. The ten parcels
were re-apportioned into one parcel and assigned the APN of 16-15-359-018-0000 and
street address 2145 East 2100 South, which is now the Site.
Investigations conducted at the site are detailed in the Remedial Action Plan (RAP, Terracon,
April 7, 2021) and are thus included in the public record. Three Amendments to the RAP
were also submitted detailing changes to soil and stockpile sampling methodology and
further characterization of specific areas of the site.
A Limited Site Investigation Report was submitted by Terracon on March 2, 2021, that
detailed the installation and sampling of three monitoring wells (MW-1 through MW-3) on
and off-site in order to determine whether there are impacts to soil and/or groundwater
relating to the historical on-site LUST facility and to monitor the potential impacts over time.
The monitoring wells were planned to be drilled to approximately 30 feet bgs, but MW-3
was only drilled to 26.5 feet bgs due to refusal. The wells were later developed, surveyed,
and sampled.
Groundwater from MW-1 had detections of tetrachloroethylene (PCE) and trichloroethylene
(TCE) above United States Environmental Protection Agency (EPA) Maximum Contaminant
Levels (MCLs) and PCE above the EPA Commercial Vapor Intrusion Screening Level (VISL).
Groundwater from MW-2 detected PCE above the EPA MCL and EPA Residential VISL. None
of the borings encountered soils with chlorinated compounds above EPA Regional Screening
Levels (RSLs).
Monitoring Well MW-3 could not be developed or sampled as it never yielded groundwater.
Monitoring Well MW-1 and MW-2 only periodically yielded enough groundwater to accurately
sample, and recharge was slow. Additionally, it was likely that MW-1 would eventually need
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 2
to be abandoned due to planned construction of a retail and residential building over that
location.
A Revised Site Management Plan Outline was submitted to then DWMRC Project Manager,
Dale Urban, on February 17, 2022, as part of the continuing discussions concerning post-
construction site management and groundwater monitoring (Appendix D). The memo
detailed the construction of two new on-site monitoring wells (MW-4 and MW-5), one on-
site replacement monitoring well (MW-1A), and two off-site replacement monitoring wells
(MW-2A and MW-3A). The replacement wells MW-1A through MW-3A would be drilled to
deeper depths in order to ensure adequate groundwater recharge and accurate sampling
and be consistent with the new wells being constructed at the site. The memo detailed five
years of groundwater monitoring to be conducted post remedial action, with the first year
consisting of quarterly sampling events, semi-annual sampling for the following two years,
and annual sampling for the final two years.
The first year of quarterly sampling events was completed in 2024. This report documents
the first semi-annual groundwater monitoring event for 2025.
Exhibit 1 (Appendix A) presents a topographic map of the area. Exhibit 2 (Appendix A) is a
site diagram that shows the monitoring well locations. The replacement wells are labeled as
MW-1A, MW-2A, and MW-3A.
1.2 Soil Boring and Monitoring Well Installation
The original monitoring wells MW-1, MW-2, and MW-3 were first abandoned properly by
removing the well box. The 2-inch diameter PVC pipe was then filled with hydrated
bentonite chips. The well casing was then broken and the surface was restored to its original
condition (concrete, asphalt, or native soil). Since these wells did not exceed 30 feet bgs,
they were not subject to permitting under the Division of Water Rights.
Prior to monitoring well (new and replacement) drilling and installation, the public utility
location service (Blue Stakes of Utah) was notified at least 48 hours prior to digging or
drilling as required by law. In addition, a subcontracted private utility location service,
Earthview Technology Inc., was used to identify and mark subsurface utilities around each
well location. A Non-Production Well Application was filed with the State of Utah Division of
Water Rights, which is required for any monitoring well that extends below 30 feet bgs. The
groundwater monitoring wells were drilled by Cascade Environmental from January 9, 2024,
to January 12, 2024, using a limited-access sonic drill rig. During drilling, the soil was
logged and field-screened using sensory methods and a photoionization detector (PID) to
detect the presence of VOCs. Please refer to the soil boring and monitoring well construction
logs in Appendix C. The monitoring wells were drilled to an approximate depth of 40 feet
bgs.
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 3
The monitoring wells were constructed as follows:
Installation of 20 feet of 2-inch diameter (20-40 feet bgs), 0.010-inch machine
slotted polyvinyl chloride (PVC) well screen with a threaded bottom cap.
Installation of 2-inch diameter, threaded, flush-joint PVC riser pipe to the surface.
Addition of pre-sieved silica sand pack for annular sand pack around the well screen
from the bottom of the boring to approximately 2 feet above the top of the well
screen.
Placement of hydrated bentonite chips above the sand pack to just below the well
box (approximately one-foot bgs).
Installation of a 7-inch diameter, circular, bolt-down, steel, monitoring well cover
with a locking well cap inset in a flush-mount concrete well pad.
After installation and prior to sampling, the wells were developed using a surge block and
bailer. Development continued until parameters (pH, temperature, dissolved oxygen (DO),
and conductivity) stabilized to have consecutive readings be within approximately 10% or
the when the well went completely dry multiple times after multiple bailing events. At least
nine purge volumes (calculated volume of water present in the water column) were
extracted from each monitoring well. Well development forms are provided in Appendix E.
Soil cuttings collected during drilling were placed in 55 gallon drums and picked up and
disposed of by E.T. Technologies, Inc. Purge water collected during well development and
later sampling was spread onsite and allowed to infiltrate into the ground.
1.3 Groundwater Elevation Survey
The elevation of the tops of the well casings were surveyed relative to an arbitrary semi-
permanent on-site benchmark. Horizontal locations were determined via an Arrow GPS unit
with sub-meter accuracy. Groundwater levels were measured in the monitoring wells prior
to groundwater sampling. The measured water levels were used in combination with the
casing elevations to evaluate groundwater elevations, direction of groundwater flow, and
gradient. Exhibit 3 (Appendix A) indicates the approximate groundwater gradient and flow
at the site. Based on the most recent data collected during this sampling event,
groundwater flows to the southwest across the site consistent with historical studies.
1.4 Scope of Services
The scope of work was to sample the five groundwater monitoring wells associated with the
site to assess the current groundwater conditions. This is the fifth groundwater sampling
event conducted at the site. The first four sampling events were conducted on a quarterly
basis. Based on the approved Site Management Plan (SMP), sampling is now conducted on a
semi-annual basis. This event was the first of four proposed semi-annual groundwater
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 4
monitoring events. Semi-annual and future annual groundwater monitoring events are
detailed in the SMP.
1.5 Standard of Care
Terracon’s services were performed consistent with generally accepted practices of the
profession undertaken in similar studies in the same geographical area during the same
time period. Please note that Terracon does not warrant the work of laboratories, regulatory
agencies, or other third parties supplying information used to prepare the report. These
services were performed in accordance with the scope of services agreed with you, our
client, as reflected in our proposal, and were not restricted by ASTM E1903-19.
1.6 Additional Scope Limitations
Findings, conclusions, and recommendations resulting from these services are based upon
information derived from the on-site activities and other services performed under this
scope of services. Such information is subject to change over time. Certain indicators of the
presence of hazardous substances, petroleum products, or other constituents may have
been latent, inaccessible, unobservable, non-detectable, or not present during these
services, and we cannot represent that the site contains no hazardous substances, toxic
materials, petroleum products, or other latent conditions beyond those identified during this
investigation. Subsurface conditions may vary from those encountered at specific borings or
wells or during other surveys, tests, assessments, investigations, or exploratory services;
the data, interpretations, findings, and recommendations are based solely upon data
obtained at the time and within the scope of these services.
1.7 Reliance
This report has been prepared for the exclusive use and reliance of Rockworth Companies
and the Utah Department of Environmental Quality (UDEQ). Use or reliance by any other
party is prohibited without the written authorization of the Rockworth Companies and
Terracon.
Reliance on the report by the client and all authorized parties will be subject to the terms,
conditions, and limitations stated in the proposal, report, and Terracon’s Terms and
Conditions. The limitation of liability defined in the Terms and Conditions is the aggregate
limit of Terracon’s liability to the client and all relying parties.
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 5
2.0 Groundwater Sampling Event
2.1 Groundwater Sample Collection
On June 16, 2025, Terracon collected groundwater samples from the three on-site
monitoring wells (MW-1A, MW-4, and MW-5) and two off-site monitoring wells (MW-2A and
MW-3A).
Wells were sampled via low flow sampling standard operating procedures, which included
the use of a peristaltic pump and new polyethylene tubing per well. Care was taken to
ensure that the tubing was placed approximately halfway between the top of the water
column and the bottom of the screen when samples were collected. Stabilization parameters
including temperature, pH, conductivity, DO, and oxygen reduction potential (ORP) were
recorded as measured by a YSI water quality meter. Wells were sampled when field
parameters stabilized as defined by three consecutive readings that were within
approximately 10 percent of each other. Purge water was collected in a 55-gallon drum
currently being stored on-site. Appendix F includes the field notes associated with the
groundwater sampling event.
2.2 General Observations
Depth-to-water measurements and relative groundwater elevations are presented in Table 1
(Appendix B). Relative groundwater elevations at the site ranged between 68.47 (MW-3A)
and 77.85 (MW-5) feet above an arbitrary established benchmark.
The groundwater gradient at the site was determined using ArcGIS Pro and scaling the area
in order to interpolate locations of contour lines to show the gradient. The direction of
groundwater flow is generally toward the southwest (Exhibit 3, Appendix A), consistent with
historical data. Free product was not observed in any monitoring wells during this sampling
event.
3.0 Laboratory Analytical Methods
All groundwater samples were collected and placed in laboratory-prepared containers,
labeled, placed on ice in a cooler, and transported to Pace Analytical National Center for
Testing and Innovation (Pace Analytical) located in Mount Juliet, Tennessee. The
groundwater samples were submitted for analysis of VOCs using EPA Method 2060B, Total
Petroleum Hydrocarbons (TPH) Gasoline Range Organics (GRO) and TPH Diesel Range
Organics (DRO) using EPA Method 8015. The executed chain-of-custody form and laboratory
data sheets are provided in Appendix H.
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 6
4.0 Data Evaluation
Results of the groundwater sampling event are summarized in Table 2 (Appendix B).
Sample locations are shown on Exhibit 2 (Appendix A). As presented in Table 2, the
following VOCs exceeded a regulatory screening level.
Well Analyte Exceedance
MW-1A
Chloroform
Naphthalene
PCE
Residential VISL
Commercial VISL
Commercial VISL, MCL
MW-2A
Chloroform
PCE
TCE
Residential VISL
Commercial VISL, MCL
Residential VISL
MW-3A Chloroform
PCE
Residential VISL
Commercial VISL, MCL
MW-4 Chloroform
PCE
Residential VISL
Commercial VISL, MCL
MW-5 PCE Commercial VISL, MCL
PCE exceeded the Commercial VISL in the three on-site wells and two off-site wells.
Residential VISL exceedances of chloroform were reported in each well except for MW-5,
and Residential VISL exceedances of TCE was reported in MW-2A. The adjoining properties
currently operate as commercial businesses.
Petroleum hydrocarbons were reported above the laboratory detection limits in MW-1A and
MW-5; however, the concentrations reported were below the DERR’s ISLs for petroleum
hydrocarbons in groundwater.
4.1 Quality Control
Quality control for the sampling program was provided by using standardized sample
collection and handling methods, documenting pertinent field information, and keeping
chain-of-custody records, as well as using a Utah-certified laboratory. All sampling
procedures followed Terracon’s Standard Operating Procedures and industry practices.
A review of the field procedures indicates that standard operating procedures were followed
with regards to sample collection, handling, and documentation. The analytical laboratory
report indicated that samples were extracted and analyzed within appropriate sample
holding times. Internal laboratory QA/QC procedures and results are presented in the
laboratory report and were within acceptable limits set by the laboratory, except where
noted.
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 7
5.0 Findings And Conclusions
On-Site Monitoring Well Results
PCE in groundwater is elevated at the site above Residential and Commercial VISLs (Exhibit
7). Results from this recent sampling event indicates that PCE concentrations in
groundwater are continuing to significantly decrease in wells MW-1A, MW-4, and MW-5. PCE
concentrations have decreased 65%, 81%, and 67% in on-site wells MW-1A, MW-4, and
MW-5, respectively since groundwater sampling began. TCE was not detected above
Residential VISLs in any on-site wells. Neither TPH-GRO nor TPH-DRO exceeded the ISLs. A
Vapor Intrusion Mitigation System (VIMS) has been installed at the site to mitigate potential
vapor intrusion associated with the elevated PCE in groundwater. It is now fully operational
and working properly. Extensive soil removal has occurred at the site, and any possible on-
site source of the contamination has been removed. If the site is considered a source of the
PCE contamination, it is expected that the PCE concentrations in these onsite wells will
continue to decrease over time with some fluctuation.
As part of the SMP, Terracon proposed conducting vacuum testing and vapor sampling in
order to verify that the VIMS is operating properly. The samples were collected in February
2025 and were analyzed for VOCs per EPA Method TO-15. The vacuum test indicated that
the system is working properly. Non-detect VOCs readings do not indicate a flaw in the
system as numerous factors indicate whether VOCs may be present in a particular riser
sample at that time period (amount of vacuum, weather conditions, lack of VOCs in areas
where the piping feeds into the riser, VOC migration in the groundwater at depth, etc.).
Based on the results of the VIMS testing, DWMRC requested that indoor air sampling be
conducted near riser R-2 where PCE and TCE concentrations were the highest. Both PCE and
TCE were non-detect in this indoor air sampling, indicating that the VIMS is properly venting
soil gas through the risers to mitigate vapor intrusion into Building 1 (south).
A former gas station was located in the southwest portion of the site, near monitoring well
MW-1A. Results indicate groundwater in this area does not appear to be contaminated with
petroleum-related hydrocarbons (TPH-GRO, TPH-DRO, benzene, toluene, ethylbenzene,
xylenes, and naphthalene) above regulatory screening levels. Naphthalene was detected at
an estimated concentration (J value) above the Commercial VISL during this sampling
event, but that is an estimated value and the first time a naphthalene exceedance was
observed. This will continue to be monitored in subsequent sampling events. The
contaminated soil has been excavated and removed in this area to the extent practicable.
TPH-GRO and TPH-DRO were either non-detect or detected below the ISL for three
consecutive groundwater sampling events conducted at well MW-1A. Based on these results,
closure of the DERR LUST portion of the site should be considered.
2025 Semi-Annual Groundwater Monitoring Report
21 st and 21st , Salt Lake City, Utah
July 10, 2025 | Terracon Project No. 61197460
Facilities | Environmental | Geotechnical | Materials 8
Off-Site Monitoring Well Results
Off-site wells MW-2A and MW-3A exceeded the Commercial VISL for PCE (Exhibit 8).
Concentrations of PCE reported in the replacement monitoring well (MW-2A) were
considerably higher than concentrations reported at the initial well location (MW-2), which
did not exceed the Commercial VISL. Results from this groundwater sampling event indicate
a decrease in PCE concentration from the previous sampling event, and PCE concentrations
have decreased 64% in MW-2A since the initial sampling event. PCE concentrations in MW-
3A are above the initial sampling event but have decreased since the last event.
A risk evaluation was conducted using data from off-site monitoring well MW-2A using the
EPA Regional Screening Level (RSL) calculator to evaluate if the cumulative risk posed by
chemicals remaining in the off-site groundwater represent a human health risk at levels
above target maximum risk levels and hazard indices. A hazard quotient of 1.0 was used
and a target risk of 10-6 was selected to be conservative. Although this site is commercial,
the scenario was run as “Resident.” The concentrations of detected VOC analytes were
added to the RSL calculator. The results are presented below and shown in Appendix G.
The cumulative carcinogenic risk posed by the remaining chemicals in the groundwater off-
site is 1.78 x 10-5, which is above the target excess residential cancer risk of 1 x 10-6 but
below the excess commercial residential cancer risk of 1 x 10-4. The calculated Hazard Index
is 3.65. Both of these values have been decreasing over time. While this is above the target
level for residential exposure, land use around MW-2A and 3A is commercial, the
groundwater is more than 25 feet below the surface, and the area is capped with concrete
or asphalt.
Based on recent research conducted by Terracon, an Environmental Covenant (EC) was
issued for the dentist office located in the southwest corner of the intersection where MW-
3A is located. The EC stated that the current on-site building is equipped with a 3,000
square foot CIM Vapor Barrier beneath the concrete slab for the building. Additionally,
indoor air sampling was conducted by Terracon in April 2025 for the property owner within
the basement of this building. Results of this sampling event indicate that concentrations of
PCE and TCE were both non-detect, and other VOCs were non-detect or detected orders of
magnitude below regulatory screening levels.
Terracon recommends monitoring these locations for the next events in order to determine
whether contaminant concentrations continue to decrease. A risk evaluation will be run after
each sampling event, and further investigation will be considered (i.e., soil gas
investigation) for the MW-2A area if carcinogenic commercial land use exceedances are
determined.
Appendix A
Exhibits
Appendix B
Data Tables
Table 1
21st and 21st Properties
2100 South 2100 East, Salt Lake City, Utah
Well Construction and Groundwater Elevation Data
Well ID Well Diameter
(inches)
Screened
Interval
(ft-bgs)
Well Depth
(feet)
Top of Casing
Elevation
(feet)
Date
Depth to
Water
(ft-btoc)
Ground Water
Elevation
(feet)
97.65 03/21/24 24.89 72.76
97.36 06/21/24 24.70 72.66
97.36 09/25/24 24.31 73.05
97.36 12/06/24 24.67 72.69
97.36 6/16/2025 24.79 72.57
96.09 03/21/24 27.78 68.31
95.79 06/21/24 26.38 69.41
95.79 09/25/24 25.90 69.89
95.79 12/06/24 26.24 69.55
95.79 6/16/2025 26.26 69.53
96.10 03/21/24 28.88 67.22
95.80 06/21/24 27.40 68.40
95.80 09/25/24 26.91 68.89
95.80 12/06/24 27.32 68.48
95.80 6/16/2025 27.33 68.47
NM 03/21/24 24.90 NM
100.23 06/21/24 23.88 76.35
100.23 09/25/24 23.53 76.70
100.23 12/06/24 23.83 76.40
100.23 6/16/2025 24.01 76.22
102.49 03/21/24 25.27 77.22
102.20 06/21/24 24.25 77.95
102.20 09/25/24 23.95 78.25
102.20 12/06/24 24.23 77.97
102.20 6/16/2025 24.35 77.85
NOTES:
ft-bgs = Feet below ground surface.
ft-btoc = Feet below top of casing.
NM = Not measured.
39.86
40.27
40.04
39.88
40.21
MW-1A
MW-2A
MW-4
MW-5
2
2
2
2
2
MW-3A
20-40
20-40
20-40
20-40
20-40
Page 1 of 1 Terracon Consultants
Appendix C
Monitoring Well Boring Logs
5.0
13.0
18.0
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), greenish gray, slightly moist, fine
subangular gravel, fine to coarse-grained subrounded sand, variable clay, zones of sand with gravel
odor
SILT (ML), light brownish gray to greenish gray, slightly moist, soft, non-plastic, some caly and fine
sand with SM lenses present, clayey at bottom odor.
SILTY SAND (SM), olive brown to greenish gray, slightly moist, fine to medium-grained subrounded
sand, some SP layers.
Well completed
with traffic-rated
well box and
7-inch well cover.
2" Blank PVC
0-20'
Hydrated
bentonite 1-18'
2.0
565.5
266.1
981.2
558.6
583.2
325.5
469.9
552.3
295.7
718.9
864.7
707.1
615.4
715.1
292.2
588.6
242.9
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 1 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-10-2024
WELL LOG NO. MW-1A
Rockworth Companies
Driller: Cascade
Well Completed: 01-11-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-1
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
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10
15
Well Completion:
INSTALLATION DETAILS
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 27 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
19.0
24.0
31.0
POORLY GRADED SAND (SP), reddish brown, moist, fine to medium-grained subrounded sand,
minor silt, coarse sand, and fine gravel.
CLAYEY SAND (SC), reddish brown, moist, fine to coarse-grained subrounded sand, with fine
gravel, zones of gravel with sand and clay locally.
Cobbles encountered 22 ft bgs, more gravel.
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), reddish brown, moist to wet, fine
subangular gravel, fine to coarse-grained subrounded sand, variable clay, some cobbles. More clay
25-27 ft bgs. More cobbles 27 ft.
LEAN CLAY (CL), reddish brown, moist to wet, soft to firm, medium plasticity, thin SM and SP
layers present.
Silica Sand Pack
18'-30'
2" slotted (0.010
in) PVC Screen
20'-40'
72.4
51.9
1635
572.4
278.2
147.2
106.5
81.9
139.1
15.1
8.2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 2 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-10-2024
WELL LOG NO. MW-1A
Rockworth Companies
Driller: Cascade
Well Completed: 01-11-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-2
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
20
25
30
35
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 27 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
40.0
LEAN CLAY (CL), reddish brown, moist to wet, soft to firm, medium plasticity, thin SM and SP
layers present.(continued)
Boring Terminated at 40 Feet
0.0
0.0
0.0
0.0
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 3 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-10-2024
WELL LOG NO. MW-1A
Rockworth Companies
Driller: Cascade
Well Completed: 01-11-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-3
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
40
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 27 ft bgs.
WATER LEVEL OBSERVATIONS
100
RE
C
O
V
E
R
Y
(
%
)
0.3
1.1
4.7
6.1
9.0
15.0
ASPHALT, Approximately 4 inches asphalt.
FILL - POORLY GRADED GRAVEL WITH SAND (GP), dark brown to olive brown, moist, fine
subangular gravel, fine to coarse-grained subrounded sand, some silt and clay.
SILT (ML), dark brown to yellowish brown, slightly moist, firm, non-plastic, some clay and clayey
zones, siltier with depth.
SILTY SAND (SM), yellowish brown, slightly moist, fine sand, minor coarser sand and isolated fine
gravels.
LEAN CLAY (CL), light brownish gray, moist, soft, medium plasticity, minor yellowish brown
mottling.
LEAN CLAY (CL), light brownish gray, moist, firm, low to medium plasticity, yellowish brown
mottling, some apparent silty layers.
SILTY SAND (SM), light brownish gray, moist, fine sand, variable silt.
Well completed
with traffic-rated
well box and
7-inch well cover.
2" Blank PVC
0-20'
Hydrated
bentonite 1-18'
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 1 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-11-2024
WELL LOG NO. MW-2A
Rockworth Companies
Driller: Cascade
Well Completed: 01-11-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-4
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
5
10
15
Well Completion:
INSTALLATION DETAILS
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 33 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
21.0
22.1
22.4
26.1
30.0
32.0
33.0
34.5
SILTY SAND (SM), light brownish gray, moist, fine sand, variable silt.(continued)
Thin gravel with sand layer (GP)
CLAYEY SAND (SC), reddish brown, moist, fine sand, clay with sand locally, clay is soft with
medium plasticity.
LEAN CLAY (CL), reddish brown, moist, hard, medium plasticity.
CLAYEY SAND (SC), reddish brown, moist, fine to medium-grained subrounded sand, minor
coarser sand and isolated fine gravels, sandier than above with more gravels with depth.
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), reddish brown, moist, fine
subangular gravel, fine to medium-grained sugrounded sand, some coarser gravel, SC with gravel
locally, clay is firm with medium plasticity, less gravels with depth.
LEAN CLAY WITH SAND (CL), reddish brown, moist, medium plasticity, fine-grained sand,
localized medium to coarse gravel.
CLAYEY SAND (SC), reddish brown, moist, fine to medium-grained sand, minor layers of coarser
sand, medium plasticity clay.
Increased sand, trace isolated fine gravels.
LEAN CLAY WITH SAND (CL), reddish brown, wet, firm, some silt, no gravel.
LEAN CLAY WITH SAND (CL), light grayish brown, wet, firm, low plasticity, wiht 2" lenses of sand.
Silica Sand Pack
18'-30'
2" slotted (0.010
in) PVC Screen
20'-40'0.4
0.2
0.4
0.4
0.6
0.2
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 2 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-11-2024
WELL LOG NO. MW-2A
Rockworth Companies
Driller: Cascade
Well Completed: 01-11-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-5
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
20
25
30
35
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 33 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
38.5
40.0
LEAN CLAY WITH SAND (CL), light grayish brown, wet, firm, low plasticity, wiht 2" lenses of sand.
(continued)
Soft sand with clay layer.
LEAN CLAY WITH SAND (CL), light grayish brown, wet, soft, low plasticity, isolated fine to coarse
subrounded gravel.
Boring Terminated at 40 Feet
0.0
0.6
0.8
0.4
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 3 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-11-2024
WELL LOG NO. MW-2A
Rockworth Companies
Driller: Cascade
Well Completed: 01-11-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-6
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
40
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 33 ft bgs.
WATER LEVEL OBSERVATIONS
100
RE
C
O
V
E
R
Y
(
%
)
0.5
1.6
4.6
6.3
9.2
14.8
TOPSOIL, Approximately 6 inches topsoil
FILL - POORLY GRADED GRAVEL WITH SAND (GP), dark brown to olive brown, moist, fine
subangular gravel, fine to coarse-grained subrounded sand, some silt and clay (GP-SC locally).
SILT (ML), dark brown to yellowish brown, slightly moist, firm, non-plastic, some clay in upper
portion.
SILTY SAND (SM), yellowish brown, slightly moist, fine sand, variable silt.
LEAN CLAY (CL), light brownish gray, moist, soft, medium plasticity.
LEAN CLAY (CL), light brownish gray, moist, soft to firm, low to medium plasticity, yellowish brown
mottling.
SILTY SAND (SM), light brownish gray, moist, fine sand, variable silt with apparent thin silty lenses.
Well completed
with traffic-rated
well box and
7-inch well cover.
2" Blank PVC
0-20'
Hydrated
bentonite 1-18'
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 1 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-12-2024
WELL LOG NO. MW-3A
Rockworth Companies
Driller: Cascade
Well Completed: 01-12-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-7
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
5
10
15
Well Completion:
INSTALLATION DETAILS
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountred approximately 31 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
21.5
22.5
22.9
24.6
26.0
29.5
32.1
35.0
SILTY SAND (SM), light brownish gray, moist, fine sand, variable silt with apparent thin silty lenses.
(continued)
Thin gravel layer 18.7 ft.
CLAYEY SAND (SC), reddish brown, moist, fine sand, some coarser sand and occasional fine
gravel, clay with sand (CL) locally, clay is firm with low plasticity.
LEAN CLAY (CL), reddish brown, moist, firm, low to medium plasticity.
CLAYEY SAND (SC), reddish brown, slightly moist, fine to medium-grained subrounded sand,
some fine subangular gravels (GP-GC locally), more gravels with depth. Transitional bottom contact.
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), reddish brown, slightly moist, fine
subangulr gravel, some coarse gravel and cobbles, fine to medium-grained subrounded sand, variable
clay - GP with sand locally.
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), reddish brown, slightly moist, fine
angular gravel, soft and low plasticity clay, cobbles present.
CLAYEY SAND (SC), light grayish brown, moist to wet, soft clay, trace fine gravel.
LEAN CLAY WITH SAND (CL), light reddish brown, wet, trace fine gravel.
POORLY GRADED GRAVEL WITH SAND (GP), reddish brown, wet, fine to coarse subrounded to
subangular gravel, cobbles present. 2-4" silty lenses with trace clay present.
Silica Sand Pack
18'-30'
2" slotted (0.010
in) PVC Screen
20'-40'0.9
0.4
0.4
0.6
0.8
0.3
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 2 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-12-2024
WELL LOG NO. MW-3A
Rockworth Companies
Driller: Cascade
Well Completed: 01-12-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-8
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
20
25
30
35
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountred approximately 31 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
36.5
38.8
40.0
CLAYEY SAND (SC), reddish brown, wet, with silt and fine subrounded gravel.
LEAN CLAY WITH SAND (CL), light reddish brown, wet, firm.
Boring Terminated at 40 Feet
0.5
0.4
0.8
0.6
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 3 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-12-2024
WELL LOG NO. MW-3A
Rockworth Companies
Driller: Cascade
Well Completed: 01-12-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-9
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
40
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountred approximately 31 ft bgs.
WATER LEVEL OBSERVATIONS
100
RE
C
O
V
E
R
Y
(
%
)
0.5
2.5
4.9
5.9
7.5
16.2
CONCRETE, Approximately 6 inches concrete.
FILL - POORLY GRADED GRAVEL WITH SAND (GP), olive brown to yellowish brown, slightly
moist, fine subangular gravel, fine to coarse-grained subrounded sand, some silt, some thin sand
layers.
SILT (ML), dark brown, slightly moist, firm, non plastic, some clay, minor fine sand.
SILTY SAND (SM), yellowish brown, slightly moist, fine to medium-grained subrounded sand.
POORLY GRADED SAND (SP), yellowish brwon, slightly moist, fine to medium-grained
subrounded sand, minor coarse sand and fine gravel.
LEAN CLAY (CL), light brownish gray to greenish gray, moist, firm, low to medium plasticity,
yellowish brown mottling, some silt, some iron staining. Increasing moisture with depth, more silt and
fine sand (SM/ML) at very bottom.
SILTY SAND (SM), light brownish gray, moist, fine sand, greenish gray mottling, silt with minor clay
locally, dark staining and odor noted.
Well completed
with traffic-rated
well box and
7-inch well cover.
2" Blank PVC
0-20'
Hydrated
bentonite 1-18'
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 1 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-10-2024
WELL LOG NO. MW-4
Rockworth Companies
Driller: Cascade
Well Completed: 01-10-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-10
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
5
10
15
Well Completion:
INSTALLATION DETAILS
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 28 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
19.0
20.0
21.0
22.0
23.3
26.5
29.3
30.0
32.0
35.0
SILTY SAND (SM), light brownish gray, moist, fine sand, greenish gray mottling, silt with minor clay
locally, dark staining and odor noted.(continued)
POORLY GRADED SAND (SP), yellowish brown, moist, fine to medium-grained subrounded sand,
minor coarse sand and fine gravel, minor darker staining.
POORLY GRADED GRAVEL WITH SAND (GP), reddish brown to olive brown, moist, fine
subangular gravel, fine to coarse-grained subrounded sand, some silt, minor staining.
LEAN CLAY (CL), reddish brown, moist, firm, low to medium plasticity, some silt and fine sand.
POORLY GRADED SAND (SP), reddish brown, moist, fine to medium-grained subrounded sand,
some coarser sand and fine gravel.
SILTY SAND (SM), reddish brown, moist, fine sand, few thin SP layers.
Gravels and cobbles encountred.
POORLY GRADED SAND (SP), reddish brown, moist to wet, fine to medium-grained subrounded
sand, some grayish mottling, minor silt, thin coarser sand and fine gravel layers, thin silty sand layers
throughout.
POORLY GRADED GRAVEL WITH SAND (GP), reddish brown to yellowish brown, wet, fine
subangular gravel, fine to coarse-grained subrounded sand, minor silt and coarse gravel.
POORLY GRADED SAND WITH CLAY (SP-SC), reddish brown, wet, fine to medium-grained
subrounded sand, some aoarse sand and fine gravels.
LEAN CLAY WITH SAND (CL), reddish brown and light brownish gray, wet, soft to firm, medium
plasticity.
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), reddish brown, wet, fine to coarse
subangular gravel, fine to coarse-grained subrounded sand, variable clay, cobbles present.
Silica Sand Pack
18'-30'
2" slotted (0.010
in) PVC Screen
20'-40'0.4
2.1
0.1
0.4
1.0
0.0
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 2 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-10-2024
WELL LOG NO. MW-4
Rockworth Companies
Driller: Cascade
Well Completed: 01-10-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-11
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
20
25
30
35
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 28 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
38.0
40.0
POORLY GRADED GRAVEL WITH CLAY AND SAND (GP-GC), reddish brown, wet, fine to coarse
subangular gravel, fine to coarse-grained subrounded sand, variable clay, cobbles present.
(continued)
CLAYEY SAND (SC), reddish brown and light brownish gray, moist to wet, soft to firm, medium
plasticity clay, fine to medium-grained subrounded sand.
Boring Terminated at 40 Feet
0.0
0.0
0.1
0.3
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 3 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-10-2024
WELL LOG NO. MW-4
Rockworth Companies
Driller: Cascade
Well Completed: 01-10-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-12
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
40
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 28 ft bgs.
WATER LEVEL OBSERVATIONS
100
RE
C
O
V
E
R
Y
(
%
)
0.5
2.5
4.9
5.9
7.5
16.2
CONCRETE, Approximately 6 inches concrete.
FILL - POORLY GRADED GRAVEL WITH SAND (GP), olive brown to yellowish brown, dry, fine
subangular gravel, fine to coarse-grained subrounded sand, some silt, some thin sand layers.
SILT (ML), dark brown, slightly moist, firm, non plastic, some clay, minor fine sand.
SILTY SAND (SM), yellowish brown, slightly moist, fine to medium-grained subrounded sand.
POORLY GRADED SAND (SP), yellowish brwon, slightly moist, fine to medium-grained
subrounded sand, minor coarse sand and fine gravel.
LEAN CLAY (CL), light brownish gray to greenish gray, moist, firm, low to medium plasticity,
yellowish brown mottling, some silt, some iron staining. Increasing moisture with depth, more silt and
fine sand (SM/ML) at very bottom.
SILTY SAND (SM), light brownish gray, moist, fine sand, silt with minor clay locally.
Well completed
with traffic-rated
well box and
7-inch well cover.
2" Blank PVC
0-20'
Hydrated
bentonite 1-18'
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 1 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-09-2024
WELL LOG NO. MW-5
Rockworth Companies
Driller: Cascade
Well Completed: 01-09-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-13
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
5
10
15
Well Completion:
INSTALLATION DETAILS
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 27 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
19.0
20.0
21.0
22.0
23.3
25.0
27.0
30.0
SILTY SAND (SM), light brownish gray, moist, fine sand, silt with minor clay locally.(continued)
POORLY GRADED SAND (SP), yellowish brown, moist, fine to medium-grained subrounded sand,
minor coarse sand and fine gravel.
POORLY GRADED GRAVEL WITH SAND (GP), reddish brown to olive brown, moist, fine
subangular gravel, fine to coarse-grained subrounded sand, some silt.
LEAN CLAY (CL), reddish brown, moist, firm, low to medium plasticity, some silt and fine sand.
POORLY GRADED SAND (SP), reddish brown, moist, fine to medium-grained subrounded sand,
some coarser sand and fine gravel.
SILTY SAND (SM), reddish brown, moist, fine sand, few thin SP layers.
LEAN CLAY (CL), light brownish gray, moist, soft, medium plasticity, some fine sand and silt.
POORLY GRADED GRAVEL WITH SAND (GP), reddish brown, wet, fine subangular gravel, fine to
coarse-grained subrounded sand, some cobbles and clay present.
LEAN CLAY WITH SAND (CL), reddish brown, wet, soft to firm, medium plasticity, fine to
medium-grained subrounded sand, minor gravels, zones of clayey sand locally.
Silica Sand Pack
18'-30'
2" slotted (0.010
in) PVC Screen
20'-40'0.2
0.7
0.2
0.2
0.1
0.8
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 2 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-09-2024
WELL LOG NO. MW-5
Rockworth Companies
Driller: Cascade
Well Completed: 01-09-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-14
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
I
D
I
F
S
E
P
A
R
A
T
E
D
F
R
O
M
O
R
I
G
I
N
A
L
R
E
P
O
R
T
.
E
N
V
I
R
O
N
M
E
N
T
A
L
S
M
A
R
T
L
O
G
J
A
N
U
A
R
Y
2
0
2
2
_
D
R
I
L
L
L
O
G
S
.
G
P
J
T
E
R
R
A
C
O
N
_
D
A
T
A
T
E
M
P
L
A
T
E
.
G
D
T
1
/
2
5
/
2
4
WA
T
E
R
L
E
V
E
L
OB
S
E
R
V
A
T
I
O
N
S
SA
M
P
L
E
T
Y
P
E
DE
P
T
H
(
f
t
)
20
25
30
35
OV
A
/
P
I
D
(p
p
m
)
Groundwater encountered approximately 27 ft bgs.
WATER LEVEL OBSERVATIONS
100
100
100
100
100
RE
C
O
V
E
R
Y
(
%
)
40.0
LEAN CLAY WITH SAND (CL), reddish brown, wet, soft to firm, medium plasticity, fine to
medium-grained subrounded sand, minor gravels, zones of clayey sand locally.(continued)
Boring Terminated at 40 Feet
1.3
0.8
0.8
0.9
GR
A
P
H
I
C
L
O
G
See Exhibit 2LOCATION
DEPTH
The stratification lines represent the approximate transition between differing soil types and/or rock types;
in-situ these transitions may be gradual or may occur at different depths than shown.
2105 South 2100 East
Salt Lake City, Utah, Utah
SITE:
Page 3 of 3
Advancement Method:
Sonic
Abandonment Method:
Hydrated Bentonite
Notes:
Project No.: 61197460
Drill Rig: Mini Sonic
Well Started: 01-09-2024
WELL LOG NO. MW-5
Rockworth Companies
Driller: Cascade
Well Completed: 01-09-2024
Exhibit:
See Appendices for description of laboratory
procedures and additional data (if any).
CLIENT:
See Appendices for description of field procedures.
See Appendices for explanation of symbols and
abbreviations.
PROJECT: 21st and 21st
B-15
6949 S High Tech Dr Ste 100
Midvale, UT
MATERIAL DESCRIPTION
TH
I
S
B
O
R
I
N
G
L
O
G
I
S
N
O
T
V
A
L
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Appendix D
Revised Site Management Plan Outline, February 17, 2022
Appendix D
Revised Site Management Plan Outline, February 17, 2022
Memo
TO: Dale Urban, Utah DWMRC, via email
FROM: Kitty Hiortdahl, Terracon Consultants
DATE: Thursday, February 17, 2022
RE:Revised Site Management Plan Outline per Wednesday February 9, 2022 meeting
21st & 21st Properties, NEC 2100 South & 2100 East
Salt Lake City, Salt Lake County, Utah
Terracon Project No. 61197460
The following memo captures Terracon’s understanding of the February 9, 2022 meeting with
representatives from the Division of Waste Management and Radiation Control (DWMRC) including Eric
Baiden, Brad Maulding and yourself, representatives from Terracon on behalf of Rockworth Companies
(site property owner) including Ben Bowers and myself. Terracon has expanded upon the discussion
held to compose an outline of a scope of work associated with the site management plan as discussed.
It is our understanding that once corrective action with controls is implemented (i.e., the Remedial
Action Plan (RAP) is implemented fully, a Site Management Plan (SMP) including a Vapor Intrusion
Mitigation System (VIMS) design is composed and approved, and environmental deed restrictions are
recorded), a letter acknowledging that corrective action has been completed can be issued by the
DWMRC. On-going monitoring will be encompassed as part of the SMP, which is performed post
corrective action.
It was established during our discussion that the purpose of groundwater monitoring in the SMP is to
measure the results of the remedial action performed, which consisted of removal of contaminated
soils. Source mass removal subsequently should result in less contaminant mass leaching into
groundwater, thereby, reducing and/or stabilizing groundwater concentrations at the site. Per our
discussion, groundwater monitoring is also to be employed to ensure offsite receptors are not
impacted by vapor intrusion.
Plan for monitoring in the SMP is proposed as follows:
Monitoring network; Analytical via EPA Method 8260 for Volatile Organic Compounds:
Onsite - 3 monitoring wells (existing MW-1, proposed MW-4 and MW-5)
o Install 2 additional monitoring wells in the assumed plume centerline
1 near/downgradient of the former Leavitts drycleaner sump
1 between the former Leavitts drycleaner and MW-1
Offsite - 2 wells (existing MW-2 and MW-3)
Monitoring wells will be completed to a depth of 35 feet and up to 45 feet below ground surface using
hollow stem auger to ensure the seasonally low water table is captured. Additional sampling may be
coupled with the above effort as part of the Leaking Underground Storage Tank (LUST) closure
regulated under the Division of Environmental Response and Remediation.
21st and 21st SMP Outline Salt Lake City, UT
February 17, 2022 Terracon Project No. 61197460
2
Sampling Duration is proposed as:
5 years of groundwater monitoring
o 1 year quarterly (4 sampling events)
o 2 years semiannual (4 sampling events)
o 2 years annual (2 sampling events)
Plume Stability Criteria and Contingency:
Once a stable and/or decreasing plume trend is established via an appropriate statistical
method, groundwater monitoring for remedial action performance will be considered achieved.
o Termination clause established for 8 data points early for statistical analysis
o Post the establishment of a stable and/or decreasing plume, monitoring wells will be
properly abandoned (if no longer in use by the LUST program)
If plume stability is not reached within the proposed 5-year timeframe, Terracon will determine
causation and perform appropriate actions, potentially including: additional investigation,
additional remedial actions, and/or abatement.
Offsite Vapor Intrusion monitoring and Contingency:
Offsite monitoring wells (MW-2 and MW-3) will be additionally monitored for vapor intrusion
o The SMP will detail Vapor Intrusion Screening Levels (VISL) applicable to the offsite
monitoring through utilizing the EPA VISL Calculator based on land use.
If offsite groundwater concentrations exceed the calculated threshold for appropriate land use
this will trigger 1) soil gas sampling; if soil gas sampling exceeds thresholds, 2) sub slab soil
gas sampling, to determine if the offsite plume is posing a vapor intrusion risk to offsite
properties.
If sub-slab sampling exceeds thresholds for vapor intrusion, 4 quarterly rounds of coupled sub
slab and indoor air sampling will be conducted. If during any sampling event indoor air exceeds
applicable thresholds and is verified by a coupled sub-slab point, emergency actions will be
taken (i.e. mobile air purifiers).
If consistent rounds of sampling demonstrate vapor intrusion occurring through coupled indoor
air and sub slab sampling, abatement actions will be taken as appropriate (i.e. sub slab
depressurization system installation).
Multiple lines of evidence, a robust conceptual site model, building conditions review, data review and
order of magnitude evaluations would be required for a full vapor intrusion investigation. These
details are not scoped in the SMP since offsite monitoring wells are currently below the EPA RSL for
vapor intrusion. It is not suspected that actions onsite will elevate groundwater concentration and
initiate the above contingencies; they are included based on discussion. A general outline of steps is
included in this memo for completeness of the receptor pathway accounting for all potential risk.
Additional stimulations of the SMP:
A VIMS design is under review by the DWMRC, and the construction completion of the VIMS will
be included in the SMP. It is assumed the VIMS will be installed per the design; if the installation
varies from the design, changes will be reviewed by the Professional Engineer and the DWMRC
prior to modification to ensure the protectiveness level is not affected by the modifications.
Environmental Deed Restrictions will be drafted and recorded as appropriate, in general they
will:
21st and 21st SMP Outline Salt Lake City, UT
February 17, 2022 Terracon Project No. 61197460
3
o Restrict groundwater use
o Restrict soil excavation where waste is left in place at the property boundary
o Restrict new development
Vapor Intrusion clause for new development: an assessment of potential need
for VIMS or other abetment actions for any new occupied spaces onsite.
o Annual notification requirement stating these stipulations have been meet and
maintained
Including a checklist for the VIMS competency, slab competency, and other
elements which might affect the integrity and protectiveness of the VIMS and/or
vapor mitigation pathway
If CR 10-4 or greater, and HQ of 1 or greater in onsite monitoring wells, Terracon
must prove that the VIMS is protective for this risk range:
Measure exhaust from pipes and sub-slab vapor (permanent points)
If sub-slab exceeds applicable thresholds, perform sub-slab sampling
coupled with indoor air sampling post a chemical inventory of the
occupied space:
o Analyze using EPA Method TO-15 for the “drycleaner” five
PCE, TCE, cis-DCE, 1,1-DCE, and VC
o Perform 4 quarters of sampling (first event includes installation)
for sub-slab sampling and indoor air sampling
o Clause for revision
If land change use or modifications are necessitated in the future the SMP shall
be revised as appropriate.
Appendix E
Well Development Forms
Appendix F
Monitoring Well Sampling Field Notes
Appendix G
Risk Evaluation Sheets
Appendix H
Chain of Custody and Laboratory Data Sheets