DERR-2024-012447

Phase I Environmental Site Assessment
Lakeview Business Park Right of Way (ROW)
1.21 Acres (~ Three Miles of ROW)

Lakeview Substation
3.24 Acres
1600 South Sheep Lane (Approximate)
Grantsville, Utah

Prepared for:

Rocky Mountain Power
T&D Environmental Services
1407 West North Temple, Suite 120A
Salt Lake City, Utah 84116

Prepared by:

Hill West Environmental, LLC
7963 Douglas Drive
Park City, Utah 84098

Contact: Claude Dahlk, CHMM
801.450.8060

July 11, 2024

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EXECUTIVE SUMMARY

Hill West Environmental, LLC (Hill West) of Park City Utah performed a Phase I Environmental
Site Assessment (ESA) on a 3.24-acre parcel where a new electrical Lakeview Substation will be
installed and a 1.21-acres Right-of-Way (ROW) located north of the substation and along Sheep
Lane Grantsville, Utah (Subject Property) as identified in Figure 1 and Figure 2 of this report. The
parcel will be purchased by Rocky Mountain Power (RMP) to develop and maintain an
approximately three (3) mile ROW from Lakeview Substation that will provide service to the
developing area within this area.

Neither the 3.24-acre parcel or the 1.21-acre ROW is listed in any of the databases searched by EDR
Radius Map Report with GeoCheck®. However, the Subject Property is part of an Environment
Covenant (EC) and Enforceable Written Assurance (EWA) #167 of the undeveloped 900-acres east
of Sheep Lane and north of SR-112, Grantsville, Utah. The review of historic aerial photographs,
topographic maps, city directories, interviews with knowledgeable persons, and a property
reconnaissance, indicate that the Subject Property has been vacant and undeveloped since the date of
the earliest aerial photograph from 1943.

The Subject Property is currently and was historically used as pastureland for grazing. The
northeastern boundary of the Tooele Army Depot – North Area (TEAD-N) is located approximately
0.5-mile southwest of the Subject Property. Several groundwater monitoring wells associated with
the TEAD-N are located north of the Tooele Army Depot are located on the 900-acre Subject
Property. Through document review of the Groundwater Management Plan completed by Gordon
Geotechnical Engineering, Inc and interviews with the Utah Department of Environmental Quality
(UDEQ), it was confirmed that the Subject Property falls within the Groundwater Management Area
associated with a dissolved plume of trichlorethylene (TCE) originating from unlined chemical
disposal pits on the Tooele Army Depot and from warehouse/maintenance buildings near the
northeast boundary of TEAD-N (collectively referred to as a portion of “SWMU 58”).
TCE was reported in monitoring wells on the Subject Property at concentrations greater than
5 micrograms per liter in the southeastern portion of the Subject Property and generally decreasing
toward the northwest. TCE in the groundwater on the Subject Property is considered a controlled
recognized environmental condition (CREC).
No groundwater monitoring wells were observed on the Subject Property during Hill West’s Subject
Property reconnaissance and therefore should not limit development on the Subject Property for the
ROW or construction of a substation. Based on information obtained during Subject Property
reconnaissance, as well as information obtained through historical records review, interviews, and
review of relevant documents, this assessment has identified No (0) Recognized Environmental
Conditions (RECs), One (1) Controlled Recognized Environmental Conditions (CRECs), No (0)
Historical Recognized Environmental Conditions (HRECs), and No (0) Business Environmental
Conditions (BECs), in connection with the Subject Property.

Vapor Encroachment Condition (VEC): A VEC can be ruled out for this parcel where the depth to
groundwater is greater than 100 feet and based on the findings and conclusions of the Hill West
Phase II Environmental Site Assessment, Lakeview Right-of-Way report dated January 19,2024.

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Based on Subject Property conditions, Hill West recommends that RMP complete the following:

1) An Environmental Convenance (EC) and Comfort Letter from the Utah Division of Waste
Management and Radiation Control should be completed for the Subject Property. Upon
receiving the EC and Comfort Letter, an EWA should be completed for the Subject Property
to minimize possible environmental exposures requiring mitigation of the TCE
contaminants.

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TABLE OF CONTENTS

1.0 INTRODUCTION ............................................................................................................1
1.1 Purpose ...................................................................................................................1
1.2 Detailed Scope-of-Services ....................................................................................1
1.3 Limitations and Exceptions of Assessment ............................................................1
1.4 Special Terms and Conditions ................................................................................2
1.5 User Reliance .........................................................................................................2
1.6 Significant Assumptions .........................................................................................3
2.0 SUBJECT PROPERTY DESCRIPTION ......................................................................3
2.1 Location and Legal Description .............................................................................3
2.2 Subject Property and Vicinity Characteristics and Land Use ................................3
3.0 USER-PROVIDED INFORMATION ............................................................................4
3.1 Title Record ............................................................................................................4
3.2 Environmental Liens & Activity and Use Limitations ...........................................4
3.3 Specialized Knowledge ..........................................................................................4
3.4 Valuation Reduction for Environmental Issues ......................................................4
3.5 Reason for Performing Phase I ...............................................................................4
3.6 Previous Investigations and Reports ......................................................................4
4.0 RECORDS REVIEW .......................................................................................................5
4.1 Standard Environmental Record Sources, Federal and State .................................5
4.1.1 Leaking Underground Storage Tanks ...................................................... 5
4.1.2 Underground Storage Tanks .................................................................... 5
4.1.3 RCRA Transportation, Storage, and Disposal Facilities (TSDF) ............ 5
4.1.8 CERCLIS Sites ........................................................................................ 6
4.1.14 National Priority List Sites (NPL – Superfund Sites) .............................. 7
4.1.16 Unmapped Sites ...................................................................................... 8
4.2 Physical Setting Sources and Natural & Stormwater Drainage .............................8
4.3 Historical Use Information .....................................................................................8
4.3.1 Historical City Directory Listings ..........................................................................8
4.3.2 Aerial Photographs...................................................................................... 8
4.3.3 Historical Topographical Maps................................................................ 8
4.3.4 Historical Sanborn Fire Insurance Maps.................................................. 8
4.4 Relevant Documents ...............................................................................................9
4.4.1 Phase II ESA – December 2023 .................................................................. 9
5.0 SUBJECT PROPERTY RECONNAISSANCE ..........................................................10
5.1 Pits, Ponds, and Lagoons ......................................................................................10
5.2 Water Supply Wells ..............................................................................................10
5.3 Indications of Solid Waste Disposal ....................................................................10
5.4 Stained Soil and Pavement or Stressed Vegetation ..............................................10
5.5 Storage Tanks, Drums, and Containers ................................................................10
5.7 PCB-Containing Equipment .................................................................................11
5.8 Septic System .......................................................................................................11
5.9 Storm Drainage .....................................................................................................11
5.10 Other Observations ...............................................................................................11

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6.0 INTERVIEWS ................................................................................................................11
7.0 DATA GAPS ...................................................................................................................11
8.0 FINDINGS, CONCLUSIONS, AND OPINIONS ........................................................12
9.0 SIGNATURES OF ENVIRONMENTAL PROFESSIONALS .................................12
10.0 QUALIFICATIONS OF ENVIRONMENTAL PROFESSIONALS ........................13

FIGURES

Figure 1 Subject Property Location Map

Figure 2 Subject Property Location Map

Figure 3 Gordon Geotechnical Engineering, Inc. Groundwater Management Area Map

LIST OF APPENDICES

Appendix A December 21, 2023, Subject Property Visit Photographs

Appendix B Environmental Data Resources, Inc. (EDR) Reports

Appendix C Relevant Documents – Phase II Soil Investigation completed by Hill West
Environmental, 2018 Phase I ESA, Site Management Plan, Environmental
Covenant for RG Lakeview, LLC/Comfort Letter, and EWA #167, Interview
Form

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1.0 INTRODUCTION

Hill West Environmental, LLC (Hill West) performed a Phase I Environmental Site Assessment
(ESA) of on a vacant three (3) mile approximately 1.21-acre parcel proposed as a right-of way
(ROW) and a 3.24-acre parcel where the Lakeview Substation will be located north of SR-112 and
east of Sheep Lane, Grantsville, Utah as identified in Figure 1 and Figure 2 (Subject Property). The
Phase I ESA was performed at the request of Rocky Mountain Power of Salt Lake City, Utah and
was conducted in conformance with the scope and limitations of the American Society for Testing
and Materials’ (ASTM) Standard Practice for Environmental Site Assessments: Phase I
Environmental Site Assessment Process, Standard E 1527-21 and meets United States
Environmental Protection Agency (USEPA) requirements for conducting “All appropriate inquires”
(AAI).

Hill West conducted the Subject Property visit for this Phase I ESA on July 9, 2024. See Figure 1
and Figure 2 for a Subject Property location and topographic map. Photographs taken during Hill
West’s Subject Property visit are provided as Appendix A.
1.1 Purpose
The purpose of this Phase I ESA was to identify “Recognized Environmental Conditions” (RECs) at
the Subject Property, to the extent possible, as specified in ASTM E 1527-21 and AAI. Some of the
many limitations of this process are noted in Sections 1.2 through 1.5.
1.2 Detailed Scope-of-Services
Hill West's goal was to identify potential RECs, as defined by ASTM and AAI, by investigating
reported past and present use of hazardous substances and materials and petroleum products, as well
as other activities that may have resulted in potential environmental concerns. This was done by
reviewing reasonably ascertainable public records, interviewing knowledgeable persons, and
conducting a visual inspection of the Subject Property and contiguous properties. Generally, the
records review, interviews, and on-Subject Property investigations consisted of searching for
evidence of conditions of environmental concern either identified by regulatory agencies or
otherwise knowledgeable persons, or observable during the Subject Property visit.

The Subject Property was inspected for conditions such as stained ground and pavement, stressed
vegetation, unauthorized dumping, and evidence of the use, storage, or release of hazardous
materials and/or petroleum products. Reasonably ascertainable information was also gathered
regarding conditions and land use on and around the Subject Property. During this Subject Property
inspection, the ground was covered with snow and was not observable during this Subject Property
visit.
1.3 Limitations and Exceptions of Assessment
The evidence gathered from the sources used in this ESA is only as complete as the sources
themselves. Some events resulting in potential environmental contamination are not reported to the
federal, state, or local agencies, and therefore are not available for review in the public records. Hill
West cannot warrant the accuracy, or the validity of the information maintained in the records
investigated. Hill West's conclusions and statements in this report are true, accurate, and certified
subject to, limited by, and disclaimed as to the underlying accuracy and veracity of this information.

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Hill West performed this ESA in a professional manner using that degree of skill and care exercised
for similar projects under similar conditions by environmental consultants. And, as mentioned
above, the Phase I ESA was conducted to the specifications of ASTM Designation E 1527-21.
Nonetheless, there are several major qualifications that are inherent in the conduct of this or any
other environmental due diligence examination.

• First, it is difficult to predict which, if any, identified potential problems will become
actual problems in the future. Federal and state regulations continually change as do the
enforcement priorities of the applicable governmental agencies involved.

• Second, there is always the distinct possibility that major sources of future environmental
liability have yet to manifest themselves to the point where they are reasonably
identifiable through an external investigation such as the one conducted for this
assessment.

• Third, we note that the results of our investigation represent the applications of a variety
of technical disciplines to material facts and conditions associated with the subject
property. Many of these facts and conditions are subject to change over time;
accordingly, the summary and recommendations must be viewed within this context.

• Fourth, Hill West shall not be responsible for conditions or consequences arising from
relevant facts that were concealed, withheld, or not fully disclosed at the time the
evaluation was performed.

• Fifth, properties adjoining the Subject Property were only unobtrusively and visually
inspected from the vantage point of the Subject Property and public rights-of-way. Hill
West does not warrant the integrity of adjoining properties in this document. Due to
snow cover all ground surfaces were not visually inspected.
1.4 Special Terms and Conditions
The property investigated included only the property described in this ass essment as the “Subject
Property” as defined by the description in Section 2.1 of this document. Although unobtrusive
visual observations were made of adjoining properties, Hill West cannot be held responsible for
identifying conditions on adjoining properties that were not readily visible from the Subject Property
at the time of the Subject Property inspection.
1.5 User Reliance
This ESA was prepared solely for the benefit of RMP. Any use of, or reliance upon, this information
by a party other than those specified above, or any lender providing financing in connection with the
proposed transaction, shall be solely at the risk of such third party and without legal recourse against
Hill West or their respective employees, officers, or owners, regardless of whether the action in
which recovery of damages is sought based upon contract, tort (including the sole, concurrent or
other negligence and strict liability of Hill West), statute, or otherwise.

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1.6 Significant Assumptions
Significant information required to complete this assessment may have been provided by a number
of parties such as government agencies, third-party vendors, and the user as defined in Section 1.5
above. In accordance with the ASTM standard, Hill West need not independently verify the
accuracy of provided information, but may rely on the information provided, unless Hill West has
actual knowledge that certain information is incorrect, it is obvious that certain information is
incorrect based on other information obtained during the site assessment or is otherwise known to
Hill West.
2.0 SUBJECT PROPERTY DESCRIPTION
2.1 Location and Legal Description
The 1.21-acre ROW begins at Latitude (North): 40° 34’ 13.13’’, Longitude (West): 112° 21’ 59.80’’
and ends at Latitude (North): 40° 35’ 22.40’’ Longitude (West): 112° 22’ 56.88’’ Tooele County,
Utah.
The 3.24-acre parcel known as the Lakeview Substation is located at 40.5698050 - 400 34’ 11.29’’
Longitude (West): 112.3664880 – 1120 21’ 59.35’’. Refer to Figure 1 and Figure 2 for a Subject
Property location and topographic map.
2.2 Subject Property and Vicinity Characteristics and Land Use
The Subject Property and the surrounding area would be characterized as grazing for livestock
ranging from 4,489 feet above sea level (north) to 4,561 feet above sea level (south). The parcel is
currently an undeveloped area northeast of the Tooele Army Depot. The nearest surface water body
is located at Stanbury Park which is approximately 1.9 miles to the southeast of the Subject Property.
Surface water from the Subject Property would flow from south to north and east to west.

The following descriptions summarize land use to the adjacent property:

1) To the north of the Subject Property is the several business buildings located
approximately 0.25-mile away. This area is expected to be part of future development.
The elevation slopes from 4,489 to is at 4,408 feet above sea level.

2) To the west of the Subject Property is Desert Peak Complex that includes baseball fields,
swimming pool, and other recreational areas. The elevation slopes from 4,489 to 4,447
feet above sea level.

3) To the east of the Subject Property is undeveloped grazing lands with mainly sagebrush
and grasses. The elevation rises from 4,489 to 4,542 feet above sea level.

4) To the south of the Subject Property is undeveloped lands currently used as grazing areas
for livestock with mainly sagebrush and grasses. Tooele Army Depot lies beyond Utah
State Highway 112.

The topographic elevation of the Subject Property is 4,489 feet above mean sea level. The general
vicinity has several drainages that slope west to east.

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3.0 USER-PROVIDED INFORMATION

The following information regarding the Subject Property was provided to Hill West by the User.
3.1 Title Record
No Title Records were reviewed as part of this Phase I ESA.
3.2 Environmental Liens & Activity and Use Limitations
No environmental liens or other activity and use limitation (AULs) were reviewed as part of this
Phase I ESA.
3.3 Specialized Knowledge
Specialized knowledge was not provided to Hill West except as noted above and in the interview
information documented in Section 6.0 of this document, or as otherwise described below.
3.4 Valuation Reduction for Environmental Issues
No information regarding valuation reduction for environmental issues was provided to Hill West.
3.5 Reason for Performing Phase I
Hill West performed a Phase I ESA at the Subject Property on behalf of and under contract to Rocky
Mountain Power. The Phase I ESA investigation was intended to permit the user to satisfy the “All
Appropriate Inquiries” (AAI) element of the innocent landowner, contiguous property owner, and
bona fide prospective purchaser protections under CERCLA.
3.6 Previous Investigations and Reports
Hill West was provided the following documents to assist in assessing the Subject Property which
involved the entire 900-acre parcel owned by RG Lakeview, LLC:

1) Phase I ESA completed by Gordon Geotechnical Engineering, June 7, 2018
2) Site Management Plan, February 18, 2021
3) Environmental Covenant (EC) for RG Lakeview, LLC, April 20, 2021and Comfort
Letter, June 15, 2018
4) Enforceable Written Assurance (EWA) #167, June 11, 2020
5) Phase II ESA Report along the ROW completed by Hill West, December 21, 2023

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4.0 RECORDS REVIEW
4.1 Standard Environmental Record Sources, Federal and State
A report of standard environmental record sources was requested and received from Environmental
Data Resources, Inc. (EDR) of Milford, Connecticut. The databases searched are listed in the EDR
Radius Map Report, which is included in Appendix B. EDR’s report is entitled The EDR-Radius
Map with GeoCheck. A summary of some of the findings of the EDR report follows.

The 1.21-acre Subject Property begins at Latitude (North): 40° 34’ 13.13’’, Longitude (West):
112° 21’ 59.80’’ and ends at Latitude (North): 40° 35’ 22.40’’ Longitude (West): 112° 22’ 56.88’’
Tooele County, Utah.
The 3.24-acre parcel known as the Lakeview Substation is located at 40.5698050 - 400 34’ 11.29’’
Longitude (West): 112.3664880 – 1120 21’ 59.35’’. Refer to Figure 1 and Figure 2 for a Subject
Property location and topographic map.
The Subject Property was not identified in any of the state and/or federal environmental record
databases (reference EDR report for acronym details). However, the 900-acre parcel to the north and
east which this Subject Property is part of, is identified within the UDEQ Department of
Environmental Response and Remediation (DERR) website for the EC, Site Management Plan, and
EWA. The following sections summarize the results of the records review for both the Subject
Property and the applicable surrounding properties.
4.1.1 Leaking Underground Storage Tanks
In accordance with the ASTM standard followed for this ESA (E 1527-21), leaking UST (LUST)
site information was gathered for a search distance of at least one mile around the Subject Property.
No LUST sites were identified within 1-mile of the Subject Property.
4.1.2 Underground Storage Tanks/UST Finder
In accordance with the current ASTM standard E 1527-21, registered underground storage tank
(UST) site information was gathered for at least the Subject Property and nearby properties. One (1)
UST site was identified as Utah Motor Sports Campus within 0.027 miles to the west of the Subject
Property.
4.1.3 RCRA Transportation, Storage, and Disposal Facilities (TSDF)
In accordance with the ASTM standard followed for this ESA (E 1527-21), RCRA transportation,
storage, and disposal (TSDF) site information was gathered for a search distance of 1-mile around
the Subject Property. The Subject Property was not listed as a TSD facility. However, there is one
(1) identified RCRA-TSDF facility identified as the Tooele Army Depot which is 0.320 miles to the
south of the Subject Property.

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4.1.4 RCRA-LQG
In accordance with the ASTM standard followed for this ESA (E 1527-21), Resource Conservation
and Recovery Act (RCRA-LQG) Large Quantity Generator information was gathered for the Subject
Property and adjoining properties within 1-mile radius. The Subject Property was not listed as a
RCRA-LQG facility. EDR reports that there is one (1) identified RCRA-LQG facility identified as
the Tooele Army Depot which is 0.320 miles to the south of the Subject Property.
4.1.5 Historical Auto Stations
EDR Hist Auto: EDR Exclusive Historical Auto Stations A review of the EDR Hist Auto list, as
provided by EDR, has revealed that there is one (1) EDR Hist Auto site within 0.027 miles of the
Subject Property. The site is identified as Miller Motorsports Park.
4.1.6 FINDS
A review of the FINDS list, as provided by EDR, dated 02/09/2024 has revealed that there is one (1)
FINDS sites within 0.25-mile of the Subject Property. This site was identified as Purple Innovation.
4.1.7 RCRA-NonGen/ NLR
In accordance with the ASTM standard followed for this ESA (E 1527-21), Resource Conservation
and Recovery Act (RCRA-NonGen) Non-Generators of Hazardous Waste Information were
gathered within a search distance of 1-mile from the Subject Property. The Subject Property was not
listed as a RCRA-NonGen facility/No Longer Regulated (NLR). EDR reports that there is one (1)
RCRA-NonGen facility located 0.016 miles to the south of the Subject Property. This site was
identified as Reckitt Benckiser Logistics Center.

4.1.8 CERCLIS Sites
In accordance with the ASTM standard followed for this ESA (E 1527-21), Comprehensive
Environmental Response, Compensation, and Liability Information System (CERCLIS, a.k.a.
‘Superfund’) site information was gathered for a search distance of ½-mile around the Subject
Property. The Subject Property was not listed in CERCLIS, however EDR reports that there is one
(1) identified CERCLIS Site identified as the Tooele Army Depot which is 0.320 miles to the south
of the Subject Property.

4.1.9 ECHO/PFAS ECHO
Enforcement & Compliance History Information A review of the ECHO list, as provided by EDR,
and dated June 24, 2023, has revealed that there is one (1) ECHO site within the requested target
property search radius.
PFAS ECHO: Facilities in Industries that May Be Handling PFAS Listing A review of the PFAS
ECHO list, as provided by EDR, and dated July 5, 2023, has revealed that there is one (1) PFAS
ECHO site within 0.019 miles of the requested target property. This site was identified as the
Deseret Peak Sewer Line Improvement Project.

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4.1.10 CORRACTION
In accordance with the ASTM standard followed for this ESA (E 1527-21), RCRA Corrective
Action Report site information was gathered for a search distance of 1-mile of the target property.
There is one (1) identified COR ACTION facility identified as the Tooele Army Depot which is
0.320 miles to the south of the Subject Property.
4.1.11 US ENG CONTROLS
In accordance with the ASTM standard followed for this ESA (E 1527-21), US ENG CONTROLS is
a site listed with institutional controls in place. Institutional controls include administrative
measures, such as groundwater use restrictions, construction restrictions, property use restriction and
post remediation care requirements intended to prevent exposure to contaminants remaining on site.
Deed restrictions are generally required as part of institutional controls. EDR identified one (1) US
ENG CONTROL facility identified as the Tooele Army Depot which is 0.320 miles to the south of
the Subject Property.
4.1.12 ROD
In accordance with the ASTM standard followed for this ESA (E 1527-21), Record of Decision
(ROD) information was gathered at a search distance of 1-mile from the target property. There is
one (1) identified as a ROD facility identified as the Tooele Army Depot which is 0.320 miles to the
south of the Subject Property.
4.1.13 Department of Defense (DOD) Sites
In accordance with the ASTM standard followed for this ESA (E 1527-21), DOD was gathered for a
search distance of 1-mile around the Subject Property. There is one (1) identified DOD facility
identified as the Tooele Army Depot which is 0.180 miles to the south of the Subject Property.
4.1.14 National Priority List Sites (NPL – Superfund Sites)
In accordance with the ASTM standard followed for this ESA (E 1527-21), National Priority List
(NPL or Superfund) site information was gathered for a search distance of 1-mile around the Subject
Property. There is one (1) identified NPL facility identified as the Tooele Army Depot which is
0.320 mile to the south of the Subject Property.
4.1.15 SEMS
SEMS: SEMS (Superfund Enterprise Management System) tracks hazardous waste sites, potentially
hazardous waste sites, and remedial activities performed in support of USEPA’s Superfund Program
across the United States. The list was formerly known as CERCLIS, renamed to SEMS by the
USEPA in 2015. The list contains data on potentially hazardous waste sites that have been reported
to the USEPA by states, municipalities, private companies and private persons, pursuant to
Section 103 of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA).

This dataset also contains sites which are either proposed to or on the National Priorities List (NPL)
and the sites which are in the screening and assessment phase for possible inclusion on the NPL.
There is one (1) identified DOD facility identified as the Tooele Army Depot which is 0.320 miles to
the south of the Subject Property.

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4.1.16 Unmapped Sites
According to the EDR report no unmapped sites were identified.
4.2 Physical Setting Sources and Natural & Stormwater Drainage
According to the United States Geological Survey (USGS) 7.5-minute Lark, Utah Quadrangle map,
the Subject Property is in elevation of 4,489 feet above mean sea level (msl). The quadrangle map
and observations at the Subject Property indicate the Subject Property slopes from the south to north
and east to west.
4.3 Historical Use Information
4.3.1 Historical City Directory Listings
EDR searched for historical local street directories for the Subject Property. A copy of the EDR-
City Directory report is contained in Appendix B. No city directory listings for the Subject Property
were returned.
4.3.2 Aerial Photographs
Hill West requested historical aerial photographs from EDR, which provided nine aerial photographs
from the years 1943, 1953, 1959, 1966, 1971, 1978, 1980, 1986, 1997, 2006, 2011, 2014, and 2018.
The following is a summary of observations made during the aerial photograph review:

1943 - 1997: The Subject Property is visible in this photograph, the entire area surrounding the
parcel appears to be used for grazing of livestock. No obvious visible evidence of environmental
concerns in the area of the Subject Property was noted.

2006: The entire area to the west of the Subject Property has been developed into the Desert Peak
Complex that includes baseball fields, BMX Track, Aquatic Center and Racetracks. The Subject
Property itself has no changes and is used for grazing livestock.

2011: The Desert Peak Complex appears fully completed and in use. The Subject Property
boundaries are off a bit in this photograph with a newly installed high pressure gas line to the south
and west of the property boundary. No obvious visible evidence of environmental concerns in the
area of the Subject Property was noted.

2014: Along the ROW there was development to the north and east of the ROW.

2018: Southwest of the ROW additional construction for development is evident.
4.3.3 Historical Topographical Maps
The pertinent sections of historical USGS topographic quadrangles were obtained from EDR and are
included in Appendix B. The maps covering the Subject Property included the years 1955, 1969,
1987, 1997, 2014, 2017, and 2020. Information gained from the examination of these maps was
consistent with that of the review of historical aerial photographs.
4.3.4 Historical Sanborn Fire Insurance Maps
Historical Sanborn Fire Insurance maps were not available for the Subject Property or the
surrounding area.

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4.4 Relevant Documents
Relevant documents available for the Subject Property include:
1) Phase I ESA completed by Gordon Geotechnical Engineering, June 7, 2018
2) Site Management Plan, Feb 19, 2021
3) Environmental Covenant for RG Lakeview, LLC, April 20, 2021 and Comfort Letter,
June 15, 2018
4) EWA #167, June 11, 2020
5) Phase II ESA conducted at the Subject Property in December 2023 to address potential
RECs. Each document is discussed in further detail below with copies of the relevant
documents presented in Appendix D.
4.4.1 Phase II ESA – December 2023
In December 2023, a Phase II ESA consisting of a soil investigation was conducted for the ROW to
assess volatile organic compounds (VCOs) beneath the Subject Property. Hill West identified a
CREC for the plume of dissolved trichlorethylene (TCE) originating from unlined chemical disposal
pits on the Army Depot premises. In addition, the warehouse/maintenance buildings near the
northeast boundary of TED-N (collectively referred to as a portion of “SWMU 58”) has also
contributed to the contaminated groundwater.
On December 21, 2023, Hill West directed E.T. Technologies, Inc. of Salt Lake City, Utah, a
licensed Wyoming driller, to advance twenty (20) direct-push soil borings to depths ranging from
5 to 10-feet bgs to collect soil samples along the ROW area as identified in Figures 1 and 2.

USEPA and DERR have established Risk-based Screening Levels (RBSLs) for TCE and other
volatile organic compounds. Based on the results of the soil investigation, the following was
determined:
• Benzene was reported above the laboratory reporting limit (RL) in soil samples collected
from soil borings B-01 through B-03, B-06, and B-08 through B-14 at 5-foot bgs and B-04 at
10-feet bgs at concentrations ranging from 0.002 mg/kg to 0.004 mg/kg, below the USEPA
RSL of 5.1 mg/kg and the DERR Initial Screening Level (ISL) of 0.2 mg/kg.
• Ethylbenzene was reported above the laboratory RL in one soil sample collected from soil
borings B-10 at 10-foot bgs at a concentration of 0.003 mg/kg, below the USEPA RSL of
25 mg/kg and the DERR ISL of 5 mg/kg.
• Toluene was reported above the laboratory RL in soil samples collected from soil borings
B-01 through B-14, B-16, and B-18 at 5-foot bgs and 10-foot bgs with concentrations
ranging from 0.004 mg/kg to 0.02 mg/kg, below the USEPA RSL of 47,000 mg/kg and the
DERR ISL of 9 mg/kg.
• Total xylenes was reported above the laboratory RL in soil samples collected from soil
borings B-01 through B-14, B-16, and B-18 at 5-foot bgs and 10-foot bgs with
concentrations ranging from 0.004 mg/kg to 0.02 mg/kg, below the USEPA RSL of
2,500 mg/kg and the DERR ISL of 142 mg/kg.

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• All VOCs that were reported above the laboratory RL in soil samples are below the USEPA
Industrial RSLs and the DERR ISLs.
• Based on soil assessment data, soil in the Subject Property does not pose an unacceptable
risk to workers. No further action is required.
• The TCE contaminated groundwater plume located beneath the Subject Property that was
identified as a CREC is not likely to impact work completed for the Subject Property or the
ROW. No further action is required.
5.0 SUBJECT PROPERTY RECONNAISSANCE

Hill West’s on-Subject Property inspection of the Subject Property was performed by Mr. Claude
Dahlk, CHMM on July 8, 2024. At the time of the Subject Property visit the security fencing has
been installed where the Lakeview Substation will be constructed, and the underground power lines
have been installed along the ROW with pull-vaults for power line installation and to assist in any
future repair work.
Copies of select photographs taken during the Subject Property visit are provided in Appendix A.
The objective of the Subject Property reconnaissance was to identify conditions of potential
environmental concern and Recognized Environmental Conditions (RECs) in connection with the
Subject Property. The inspection consisted of a visual inspection of the Subject Property and an
unobtrusive inspection of adjoining properties, as visible from the Subject Property and nearby
public roadways.
5.1 Pits, Ponds, and Lagoons
No ponds, lagoons, or surface water bodies were observed on the Subject Property during the
Subject Property visit.

5.2 Water Supply Wells
Review of the State Database, 103 wells are located within one mile of the Subject Property. Based
on distance (1/8-mile) to the nearest well and topography any releases from the Subject Property
would not impact these wells.
5.3 Indications of Solid Waste Disposal
No evidence of significant improper solid waste disposal was observed at the Subject Property.
5.4 Stained Soil and Pavement or Stressed Vegetation
No visible stained soils, pavement or stressed vegetation were observed.
5.5 Storage Tanks, Drums, and Containers
No underground petroleum storage tanks, drums, containers, or other solid wastes were observed at
the Subject Property.

5.6 Floor Drains and Waste Water
No buildings are present and therefore no floor drains are present, and all water is either storm water
or snow melt.

Page 11
5.7 PCB-Containing Equipment
No oil-filled equipment was present on the Subject Property.
5.8 Septic System
No evidence of a septic system was observed at the Subject Property.
5.9 Storm Drainage
As the Subject Property is undeveloped no storm drains near the Subject Property are present.
5.10 Other Observations
None.
6.0 INTERVIEWS

Hill West interviewed Mr. Than Smith, Owner’s Representative, who has either managed the area or
has direct knowledge of past use of the Subject Property. Mr. Smith stated that he was unaware of
any unauthorized dumping, spill, hazmat responses, or other potential RECs affiliated with the
Subject Property. However, the Tooele Army Depot TCE contamination plume is a CREC for
groundwater use. Mr. Smith provided several documents for the entire 900-acre parcel owned by
RG Lakeview, LLC including:

1) Phase I ESA completed by Gordon Geotechnical Engineering June 7, 2018
2) Site Management Plan February 18, 2021
3) Environmental Covenant for RG Lakeview, LLC April 20, 2021 and Comfort Letter,
June 15, 2018
4) EWA #167, June 11,2020
7.0 DATA GAPS

No significant data gaps were identified during the course of this Phase I ESA.

Page 12
8.0 FINDINGS, CONCLUSIONS, AND OPINIONS

Hill West Environmental, LLC (Hill West) has performed a Phase I Environmental Site Assessment
in conformance with the scope and limitations of ASTM Practice E 1527-21 on the Subject Property.
In summary, as of the December 21, 2023, Subject Property reconnaissance, Hill West identified the
following RECs associated with the Subject Property:

No groundwater monitoring wells were observed on the Subject Property during Hill West’s Subject
Property visit and therefore should not limit development on the Subject Property for construction of
a substation. Based on information obtained during Subject Property reconnaissance, as well as
information obtained through historical records review, interviews, and review of relevant
documents, this assessment has identified No (0) Recognized Environmental Conditions (RECs),
One (1) Controlled Recognized Environmental Conditions (CRECs), No (0) Historical Recognized
Environmental Conditions (HRECs), and No (0) Business Environmental Conditions (BECs), in
connection with the Subject Property.

Vapor Encroachment Condition (VEC): A VEC can be ruled out for this parcel where the depth to
groundwater is greater than 100 feet and based on the findings and conclusions of the Hill West
Phase II Environmental Site Assessment, Lakeview Right-of-Way report dated January 19,2024.

Based on Subject Property conditions, Hill West recommends that RMP complete the following:

1) An Environmental Convenance and Comfort Letter from the Utah Division of Waste
Management and Radiation Control should be completed for the Subject Property. Upon
receiving the EC and Comfort Letter, an EWA should be completed for the Subject Property
to minimize possible environmental exposures requiring mitigation of the TCE
contaminants.
9.0 SIGNATURES OF ENVIRONMENTAL PROFESSIONALS

I declare that, to the best of my professional knowledge and belief, I meet the definition of
“Environmental Professional” as defined in 40 CFR Part 312.10 and I have the specific
qualifications based on education, training, and experience to assess a property of the nature,
history, and setting of the Subject Property. I have developed and performed the ‘all appropriate
inquiries’ in conformance with the standards and practices set forth in 40 CFR Part 312.

Claude Dahlk, CHMM
Project Manager

Page 13
10.0 QUALIFICATIONS OF ENVIRONMENTAL PROFESSIONALS PARTICIPATING
IN PHASE I ENVIRONMENTAL SITE ASSESSMENT

The following short resumes summarize the qualifications of the professionals who were involved in
the Phase I Environmental Site Assessment.

Claude Dahlk, CHMM
B.S., Chemistry
Mr. Claude Dahlk has a B.S. degree in Chemistry and is a Certified Hazardous Materials Manager
(CHMM), Asbestos Inspector/Management Planner/Project Designer, Underground Storage Tank
(UST) Soil and Groundwater Sampler, UST Consultant and Methamphetamine Decontamination
Specialist. Mr. Dahlk has 32 years of experience in environmental site assessment and has
completed projects in Idaho, South Dakota, Wyoming, and Utah. Mr. Dahlk’s experience also
includes site mitigation/investigation of hazardous waste/PCB/petroleum releases, mine closures,
environmental audits for various facilities including power plants, mines, and manufacturing
facilities; emergency response; extensive soil, groundwater, surface water, and air sampling; and the
preparation of Spill Prevention, Control, and Countermeasure (SPCC), Storm Water Pollution
Prevention Plan (SWPPP), Solid and Hazardous Waste Management Plans, and technical reports.

FIGURES 1, 2 and 3

Subject Property Location

LAKEVIEW SUBSTATION
UTILITY RIGHT-OF-WAY
Approximate Location of
Subject Property
LEGEND
FIGURE TITLE
DOCUMENT TITLE
CLIENT
LOCATION
PROJECT NUMBER
DATE
AS SHOWNSCALE
DJLDESIGNED BY
CDAPPROVED BY
SRMDRAWN BY
FIGURE NUMBER
1
N
0 5,0002,500
SCALE FEET
U.S.G.S. 7.5 MINUTE TOPOGRAPHIC QUADRANGLE
GRANTSVILLE, UTAH AND TOOELE, UTAH (2023)
SOURCE:
Subject
Property
UTAH
7963 Douglas Dr
Park City, UT 84098
Phone: [phone]
www.hillwestut.com
ROCKY MOUNTAIN POWER
LAKEVIEW BUSINESS PARK UTILITY
RIGHT-OF-WAY
1/8/24
SHEEP LANE
GRANTSVILLE, UTAH
Lakeview Substation
Subject Property
(Utility Right-of-Way)
Sh
e
e
p

L
a
n
e
UT-
1
1
2
Deseret Peak Complex
Utah Motorsport Campus
Lakevew Commerce Center
(Warehouse)
Purple Mattress Factory
Jabil
(Warehouse)
Undeveloped
Undeveloped
Undeveloped
Undeveloped
Approximate Location of
Subject Property
LEGEND
SUBJECT PROPERTY DETAIL MAPFIGURE TITLE
DOCUMENT TITLE
CLIENT
LOCATION
PROJECT NUMBER
DATE
AS SHOWNSCALE
DJLDESIGNED BY
CDAPPROVED BY
SRMDRAWN BY
FIGURE NUMBER
2
N
0 2,4001,200
SCALE FEET
GOOGLE EARTH (2023)SOURCE:
7963 Douglas Dr
Park City, UT 84098Phone: [phone]www.hillwestut.com
ill
Environmental
H estW
ROCKY MOUNTAIN POWER
LAKEVIEW BUSINESS PARK UTILITY
RIGHT-OF-WAY
1/8/24
2064-0037
SHEEP LANE
GRANTSVILLE, UTAH

APPENDIX A

Photographs of Site Visit
Photograph Locations Legend
Lakeview ROW
Lakeview Substation
Photograph Locations
1 mi
N
➤➤
N
Image © 2024 Airbus
Image © 2024 Airbus
Image © 2024 Airbus
#1 NW corner substation facing north #2 NW corner substation facing east
#3 NW corner substation facing south #4 NW corner substation facing west
#5 NE corner substation facing north #6 NE corner substation facing east
#7 NE corner substation facing south #8 NE corner substation facing west
#9 SE corner substation facing north #10 SE corner substation facing east
#11 SE corner substation facing south #12 SE corner substation facing west
#13 SW corner facing north #14 SW corner facing east
#15 SW corner facing south #16 SW corner facing west
#17 Right of Way (ROW) facing north #18 ROW facing east
#19 ROW facing south #20 ROW facing west
#21 ROW facing north #22 ROW facing east
#23 ROW facing south #24 ROW facing west
#25 ROW facing north #26 ROW facing east
#27 ROW facing south #28 ROW facing west
#29 ROW facing north #30 ROW facing east
#31 ROW facing south
#32 ROW facing west
#33 ROW facing north #34 ROW facing east
#35 ROW facing south #36 ROW facing west