DERR-2024-012838

Cover Page
Corrective Action Plan
Proposed First Step House
273 East 800 South, Salt Lake City, Utah
Facility ID No. 4002693, Release Site OLN
December 9, 2024 | Terracon Project No. 61247145
Prepared for:
First Step House
Salt Lake City, Utah
6952 South High Tech Dr. Ste. B
Midvale, Utah 84047
P [phone]
Terracon.com
Facilities | Environmental | Geotechnical | Materials i
Cover Letter
December 9, 2024
First Step House of Salt Lake City Utah
440 South 500 East
Salt Lake City, Utah 84102
Attn: Mr. Austin Davis
P: 801.410.5227
E:[e-mail]
RE: Corrective Action Plan
First Step House
273 East 800 South, Salt Lake City, Utah
Facility ID No. 4002693, Release Site OLN
Terracon Project No. 61247145
Dear Mr. Davis:
Terracon Consultants, Inc. (Terracon) has developed this Corrective Action Plan (CAP) for
submission to the Utah Department of Environmental Quality Division of Environmental
Response and Remediation on behalf of First Step House (client).
Corrective action is required to address petroleum-impacted soils and groundwater at the
site originating from a release from underground petroleum storage tanks. This CAP is
designed to address removal of the impacted soils, address impacted groundwater, and
facilitate re-development of the site for the new property owner.
Please contact Andrew Turner at 385-388-7028 if you have questions regarding this
information or if we can provide any other services.
Sincerely,
Terracon Consultants, Inc.
Andrew S. Turner Amy Austin
Project Manager Authorized Project Reviewer
Environmental Services
' P \ ' X V W L Q
Facilities | Environmental | Geotechnical | Materials ii
Table of Contents
1.0 Introduction ........................................................................ 1
1.1 Site Description ..................................................................................... 1
1.2 Project Information ................................................................................ 1
1.3 Objectives ............................................................................................. 2
1.4 Extent of Contamination .......................................................................... 3
1.5 Public Notice .......................................................................................... 3
2.0 Methodology ....................................................................... 3
2.1 Soil Excavation and Disposal .................................................................... 4
2.2 UST Removal (if required) ....................................................................... 4
2.3 Confirmation Soil Sampling ..................................................................... 4
2.4 Groundwater Treatment, Northwest Area .................................................. 4
2.5 Groundwater Treatment, Southeast Area .................................................. 5
2.6 Backfill and Surface Restoration ............................................................... 5
2.7 Sampling Quality Control/Quality Assurance .............................................. 5
3.0 Groundwater Monitoring Program........................................... 6
4.0 CAP Implementation Report .................................................. 6
Appendices
Appendix A Exhibits
Exhibit 1: Topographic Site Overview
Exhibit 2: Soil Boring and Soil Gas Sampling Locations
Exhibit 3: Petroleum Hydrocarbon Exceedances in Soil
Exhibit 4: Petroleum Hydrocarbon Exceedances in Groundwater
Exhibit 5: Proposed Soil and Groundwater Treatment Areas
Appendix B Analytical Data Tables
Table 1: VOCs and Petroleum Hydrocarbons in Soil
Table 2: VOCs and Petroleum Hydrocarbons in Groundwater
Table 3: VOCs in Soil Gas
Corrective Action Plan
First Step House | Salt Lake City, Utah
December 9, 2024 | Terracon Project No. 61247145
Facilities | Environmental | Geotechnical | Materials 1
1.0 Introduction
1.1 Site Description
Site Name Future First Step House
DERR Facility ID No. 4002693, Release Site OLN
Site Location/Address 273 East 800 South, Salt Lake City, Utah
General Site
Description
The site is comprised of an approximately 0.64-acre parcel
(Parcel ID. 16-07-130-036-0000)consisting of an 8,930
square-foot building with a basement, a 700 square-foot
garage, and paved parking areas.
Exhibit 1 (Appendix A) illustrates the approximate location of this parcel in relation to the
surrounding area.Exhibit 2 is a site diagram indicating the approximate locations of the
historical and recent sample locations and related features. Current redevelopment plans for
the site include residential housing (apartments).
1.2 Project Information
A Phase I Environmental Site Assessment (Phase I ESA) conducted on the property by
Terracon (January 23, 2024, Terracon Project No. 61237405) identified a Recognized
Environmental Condition (REC) associated with a historical fueling center and automotive
repair facility located at the site. Based on the lack of regulatory records or documentation
and the time frame (approximately 1959 to 1981) that the station was in operation, the
potential release of petroleum hydrocarbons or other hazardous substances to the
environment associated with this facility was identified as a REC. As the operation of the
facility occurred at a time when no regulations were in place for underground petroleum
storage tanks (USTs), there is no information on how many USTs were present at the site
and whether they were removed or are still in-place.
Terracon performed a subsequent Limited Site Investigation (LSI) (February 20, 2024,
Terracon Project No. 61247015). The work involved installing soil borings and sampling of
soil and groundwater at four locations around the current building. Additionally, two sub-
slab soil vapor points were installed in the basement of the current building to evaluate
potential soil gas impacts within the building (Appendix A Exhibit 2).
Based on field observations and analytical sample results of the LSI, the site appears to
have been impacted by a release associated with the REC (historic fueling center) identified
in the Phase I ESA. Total petroleum hydrocarbons (TPH) diesel-range organics (DRO) and
total recoverable petroleum hydrocarbons (TRPH) exceeded the Utah Initial Screening
Corrective Action Plan
First Step House | Salt Lake City, Utah
December 9, 2024 | Terracon Project No. 61247145
Facilities | Environmental | Geotechnical | Materials 2
Levels (ISLs) in soil in one location (B-1) located northwest of the current building. TPH-
DRO in groundwater exceeded Utah Tier 1 Screening Levels in one location (B-1), and TRPH
in groundwater exceeded Utah Tier 1 Screening Levels in B-4 located to the southeast of the
current building (Appendix A Exhibits 3 and 4).
Due to impacts detected in both soil and groundwater at the site, the Utah Department of
Environmental Quality (UDEQ) Division of Environmental Response and Remediation (DERR)
was notified of this historical release and the site was enrolled under their Leaking
Underground Storage Tank (LUST) oversight program (Release site OLN), which requires
the submittal of a Corrective Action Plan (CAP).
It is our understanding that the costs related to the cleanup of the release is not
reimbursable under the Petroleum Storage Tank (PST) Trust Fund and will be the
responsibility of First Step House.
1.3 Objectives
The objective of this CAP is to remove the petroleum-impacted soils and treat impacted
groundwater remaining in the vicinity of the on-site building that exceed DERR screening
levels. The soil and groundwater impacted areas are as follows:
Area around B-1 (northwest of the current building) where both soil and groundwater
exceeded DERR screening levels (Appendix A Exhibit 3). Soil in this area exceeded
the DERR ISL for TPH-DRO and TRPH. Groundwater in this area exceeded the Tier 1
Screening Level for TPH-DRO.
Area around B-4 (southeast of the current building) where groundwater exceeded the
Tier 1 Screening Level (Appendix A Exhibits 3 and 4) for TRPH.
It is believed that the area around B-1 was a historical UST cavity related to the gas station
that previously operated at the site. It is unknown what the impacts around B-4 are related
to, but it is suspected that it may have been a leaking waste oil tank or contamination from
the former dispensers.
The cleanup levels proposed for this site will be the DERR ISLs as the site is planned to
include residential apartments.
USTs, if encountered during building demolition and excavation of soils, will be properly
removed from the site. A ground penetrating radar (GPR) survey was conducted in the
suspected former UST cavity as part of the previous LSI, but no USTs were immediately
identified.
Corrective Action Plan
First Step House | Salt Lake City, Utah
December 9, 2024 | Terracon Project No. 61247145
Facilities | Environmental | Geotechnical | Materials 3
1.4 Extent of Contamination
Based on the results of the LSI, the approximate extent of soil and groundwater
contamination remaining above a screening level was estimated and is shown on Appendix
A Exhibit 3. The approximate extent of impacts are as follows:
Approximately 47 feet by 40 feet area northwest of the current building (Appendix A
Exhibit 5). Soil is anticipated to be impacted from approximately 6 to 12 feet below
ground surface (bgs) to just below the soil/groundwater interface. The excavation is
expected to extend to approximately 13 feet bgs, resulting in approximately 500
cubic yards of impacted soil. Groundwater is also impacted in this area.
Approximately 40 feet by 30 feet area southeast of the current building (Appendix A
Exhibit 5). Groundwater is impacted in this area, but soil does not appear to be
impacted. Groundwater is expected to be encountered at approximately 10 feet bgs.
It is not believed that soil is impacted directly below the current building, based on the
findings of the sub-slab vapor sampling. However, if evidence of impacted soil is present
during building demolition, additional sampling and potential soil excavation and disposal
will be conducted in impacted areas and documented in the CAP Implementation Report.
1.5 Public Notice
Prior to any excavation and sampling, the potentially affected public will be notified of the
remedial action. The public notice will be posted at the property and hand-delivered to any
adjoining properties where public comment will be solicited. Any comments or concerns
about the project will be satisfactorily addressed prior to any work being conducted.
2.0 Methodology
The proposed corrective action methodology is to demolish the existing building, excavate
and remove impacted soils in one area of the site, and treat impacted groundwater in two
locations.
The on-site building and garage will be demolished per applicable state and local regulations
and after receiving all appropriate permits and approvals. Soil and groundwater remediation
work is expected to commence upon conclusion of the building demolition work.
Prior to soil excavation work, the public utility location service (Blue Stakes) will be notified
at least 48 hours prior to digging or drilling as required by law. In addition, a subcontracted
private utility location service will be used to identify and mark subsurface utilities around
the planned excavation area.
Corrective Action Plan
First Step House | Salt Lake City, Utah
December 9, 2024 | Terracon Project No. 61247145
Facilities | Environmental | Geotechnical | Materials 4
2.1 Soil Excavation and Disposal
Soil will be excavated in the defined area (Appendix A Exhibit 3) northwest of the current
on-site building to a depth of approximately 13 feet bgs. Soils from the surface to
approximately six feet bgs (non-contaminated) will be excavated and set aside for future re-
use as backfilling material. Petroleum-impacted soils excavated from approximately six to
13 feet bgs will be transported to and disposed of at ET Technologies Soil Regeneration Site
in Salt Lake City (ET Technologies). All soils will be initially screened using a photo-
ionization detector (PID). Characterization sampling of the impacted soil will be conducted
as needed per ET Technologies requirements. Waste manifests detailing the soil disposal will
be provided in a CAP Implementation Report once the remediation is complete.
2.2 UST Removal (if required)
If USTs are encountered in the excavation, the DERR Project Manager will be immediately
notified. Any USTs encountered will be removed by a licensed UST Remover. As the site is
enrolled in the DERR remediation program, a UST closure plan may not be required if it is
located within the boundaries of the excavation area.
2.3 Confirmation Soil Sampling
Upon completion of the soil excavation, at least one confirmation soil sample will be
collected from each of the four sidewalls and one from the floor of the excavation. A total of
at least five soil samples will be collected. Samples will be collected at a specific depth
based on visual observations and field screening using a PID.
The confirmation soil samples will be submitted to Chemtech-Ford Laboratories in Sandy,
Utah, for analysis of TPH-GRO, TPH-DRO, TRPH, methyl tert-butyl ether, benzene, toluene,
ethylbenzene, xylenes, and naphthalene (MBTEXN), and volatile organic compounds (VOCs).
If a soil confirmation sample exceeds an ISL, the excavation will be extended and the
process repeated until confirmation samples report petroleum hydrocarbons below the ISLs.
2.4 Groundwater Treatment, Northwest Area
In order to reduce residual soil and groundwater impacts in the immediate vicinity of the
excavation, in situ treatment via activated carbon adsorption and enhanced biodegradation
is proposed. Approximately 1,121 pounds of BOS 200 (powdered material), 1,121 pounds of
gypsum, and 2 pounds of bacteria will be placed into the bottom of the excavation within
the groundwater and mixed with the soil. Soil backfill (the excavated soil from the top 6
feet) will then be added to the excavation and mixed with these added materials as needed
during the backfilling process. The amount of materials used will be based on supplier
Corrective Action Plan
First Step House | Salt Lake City, Utah
December 9, 2024 | Terracon Project No. 61247145
Facilities | Environmental | Geotechnical | Materials 5
recommendations and professional judgement, and the amounts used will be documented in
the CAP Implementation Report.
2.5 Groundwater Treatment, Southeast Area
In order to treat the impacted groundwater in the southeast portion of the site, in-situ
chemical injections are proposed. Approximately 20, evenly spaced, direct-push soil borings
are proposed for this area. These borings are proposed to extend to 15 feet bgs. Within
each boring, sorption and enhanced bioremediation chemicals utilizing activated carbon
(BOS 200) and gypsum will be injected into each boring from approximately 15 feet bgs to
10 feet bgs. It is expected that approximately 1,200 pounds of BOS 200 and 1,200 pounds
of gypsum will be utilized for this process. Concentrations of these chemicals will be added
at alternating vertical intervals to provide overlap and separation offsets. The injection rate
will be determined per manufacturer calculations and geology. Details of the injection
process will be documented in the CAP Implementation Report.
If evidence of contaminated soil is present in this portion of the site during the building and
basement demolition, limited excavation work (i.e., potholing) will be conducted in this area
to determine whether the contamination is more extensive. If a significant volume of
impacted soil is encountered, soil excavation and disposal along with groundwater treatment
will be implemented instead of groundwater injections. This will follow the basic excavation,
addition of chemicals, and confirmation sampling process utilized in the northwest area.
2.6 Backfill and Surface Restoration
The excavation area will be backfilled with the clean soil originally set aside from the top 6
feet of the excavation. The first several feet will be mixed with remediation chemicals as
described above based on the manufacturer’s recommendations. Additional engineered
backfilling is not proposed at the time per the owner’s request. The remaining open hole
present (approximately 7 feet deep) will be fenced and secured.
Any soil cuttings generated during the drilling conducted in the southeast portion of the site
will be spread across the site. The borings will be backfilled with bentonite chips and
finishing the existing surface soil to match the surrounding surface.
2.7 Sampling Quality Control/Quality Assurance
All oversight and sampling work during the excavation and groundwater treatment will be
under the direction of a Utah-Certified UST Consultant. All environmental samples will be
collected by a Utah-Certified Groundwater and Soil Sampler. Quality assurance for the
sampling program will include standardized sample collection, preservation, and handling
methods as well as documenting field information and keeping chain-of-custody records.
Samples will be analyzed by a Utah-certified laboratory.
Corrective Action Plan
First Step House | Salt Lake City, Utah
December 9, 2024 | Terracon Project No. 61247145
Facilities | Environmental | Geotechnical | Materials 6
3.0 Groundwater Monitoring Program
Once the CAP has been implemented and completed, the DERR will require two consecutive
quarters of groundwater sampling that document petroleum hydrocarbons as below the land
use screening levels. Three groundwater monitoring wells will be installed at the site, and
quarterly groundwater monitoring will be conducted until the site meets DERR closure
criteria. Exact locations and design of the groundwater monitoring wells will be determined
based upon site observations made during the remediation work and access. Locations of
the monitoring wells and sampling plan will be approved by the DERR prior to installation.
4.0 CAP Implementation Report
This CAP proposes excavating and properly disposing of the impacted soil, confirmation
sampling, groundwater treatment, boring injections, and backfilling the excavation. When
the work is completed, a CAP Implementation Report will be generated and sent to DERR
documenting the work and any remaining issues at the site. The locations and design of the
groundwater monitoring wells will also be detailed.
If cleanup to the unrestricted land use actions levels cannot be achieved and/or impacted
soils and groundwater remain at the site, an Environmental Covenant and Site Management
Plan may be required.
Appendix A
Exhibits
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Exhibit
terracon.comPH. 801-545-8500
6952 S High Tech Dr, Ste B
Midvale, UT
Reviewed By:
Drawn By:
Dec 2024
Date:
61247145
Project No.:
First Step House
273 East 800 South
Salt Lake City, Utah
Proposed Soil and Groundwater Treatment Areas
5
DD
AST
DATA SOURCES:
ESRI - Basemaps
@A @A
@A
@A
SV-1
SV-2
B-3 B-4
B-2
B-1
0 50 10025
Feet
³
³
@A Soil Boring
Sub-Slab Soil Gas Sample Point
Former Gas Station Footprint
Approximate Property Boundary
Proposed Soil Excavation Area
Proposed Injection Area
Appendix B
Analytical Data Tables
Table 1 - VOCs and Petroleum Hydrocarbons in Soil
First Step House - 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units RSL
Residential
RSL
Industrial ISL Tier 1 Result Q Result Q Result Q Result Q
TPH-GRO 8260B mg/kg NE NE 150 1500 <20.3 <0.627 <0.624 <0.640
TPH-DRO 8015 mg/kg NE NE 500 5000 804 <5.01 2.41 J <5.12
TRPH 9071B mg/kg NE NE 1000 10000 2530 50 J 74.2 J 87.9 J
ACETONE 8260B mg/kg 70000 1100000 NE NE <2.03 <0.0627 <0.0624 <0.0640
ACRYLONITRILE 8260B mg/kg 0.25 1.1 NE NE <0.406 <0.0125 <0.0125 <0.0128
BENZENE 8260B mg/kg 1.2 5.1 0.2 0.9 <0.0406 0.000855 J 0.00175 0.00095 J
BROMOBENZENE 8260B mg/kg 290 1800 NE NE <0.0406 <0.00125 <0.00125 <0.00128
BROMODICHLOROMETHANE 8260B mg/kg 0.29 1.3 NE NE <0.0406 <0.00125 <0.00125 <0.00128
BROMOFORM 8260B mg/kg 19 86 NE NE <0.0406 <0.00125 <0.00125 <0.00128
BROMOMETHANE 8260B mg/kg 6.8 30 NE NE <0.203 <0.00627 <0.00624 <0.00640
N-BUTYLBENZENE 8260B mg/kg 3900 58000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
SEC-BUTYLBENZENE 8260B mg/kg 7800 120000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
TERT-BUTYLBENZENE 8260B mg/kg 7800 120000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
CARBON TETRACHLORIDE 8260B mg/kg 0.65 2.9 NE NE <0.0406 <0.00125 J3 J4 <0.00125 J3 J4 <0.00128 J3 J4
CHLOROBENZENE 8260B mg/kg 280 1300 NE NE <0.0406 <0.00125 <0.00125 <0.00128
CHLORODIBROMOMETHANE 8260B mg/kg 8.3 39 NE NE <0.0406 <0.00125 <0.00125 <0.00128
CHLOROETHANE 8260B mg/kg 5400 23000 NE NE <0.203 <0.00627 <0.00624 <0.00640
CHLOROFORM 8260B mg/kg 0.32 1.4 NE NE <0.203 <0.00627 <0.00624 <0.00640
CHLOROMETHANE 8260B mg/kg 110 460 NE NE <0.101 <0.00313 <0.00312 <0.00320
2-CHLOROTOLUENE 8260B mg/kg 1600 23000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
4-CHLOROTOLUENE 8260B mg/kg 1600 23000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,2-DIBROMO-3-CHLOROPROPANE 8260B mg/kg 0.0053 0.064 NE NE <0.203 <0.00627 <0.00624 <0.00640
1,2-DIBROMOETHANE 8260B mg/kg 0.036 0.16 NE NE <0.0406 <0.00125 <0.00125 <0.00128
DIBROMOMETHANE 8260B mg/kg 24 99 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,2-DICHLOROBENZENE 8260B mg/kg 1800 9300 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,3-DICHLOROBENZENE 8260B mg/kg NE NE NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,4-DICHLOROBENZENE 8260B mg/kg 2.6 11 NE NE <0.0406 <0.00125 <0.00125 <0.00128
DICHLORODIFLUOROMETHANE 8260B mg/kg 87 370 NE NE <0.203 <0.00627 <0.00624 <0.00640
1,1-DICHLOROETHANE 8260B mg/kg 3.6 16 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,2-DICHLOROETHANE 8260B mg/kg 0.46 2 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,1-DICHLOROETHENE 8260B mg/kg 230 1000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
CIS-1,2-DICHLOROETHENE 8260B mg/kg 63 370 NE NE <0.0406 <0.00125 <0.00125 <0.00128
TRANS-1,2-DICHLOROETHENE 8260B mg/kg 70 300 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,2-DICHLOROPROPANE 8260B mg/kg 2.5 11 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,1-DICHLOROPROPENE 8260B mg/kg NE NE NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,3-DICHLOROPROPANE 8260B mg/kg 1600 23000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
CIS-1,3-DICHLOROPROPENE 8260B mg/kg NE NE NE NE <0.0406 J4 <0.00125 <0.00125 <0.00128
TRANS-1,3-DICHLOROPROPENE 8260B mg/kg NE NE NE NE <0.0406 <0.00125 <0.00125 <0.00128
2,2-DICHLOROPROPANE 8260B mg/kg NE NE NE NE <0.0406 <0.00125 J3 <0.00125 J3 <0.00128 J3
DI-ISOPROPYL ETHER 8260B mg/kg 2200 9400 NE NE <0.0406 <0.00125 <0.00125 <0.00128
ETHYLBENZENE 8260B mg/kg 5.8 25 5 23 <0.0406 <0.00125 <0.00125 <0.00128
HEXACHLORO-1,3-BUTADIENE 8260B mg/kg 1.2 5.3 NE NE <0.0406 <0.00125 <0.00125 <0.00128
ISOPROPYLBENZENE 8260B mg/kg 1900 9900 NE NE <0.0406 <0.00125 <0.00125 <0.00128
P-ISOPROPYLTOLUENE 8260B mg/kg NE NE NE NE <0.0406 <0.00125 <0.00125 <0.00128
2-BUTANONE (MEK)8260B mg/kg 27000 190000 NE NE <0.406 <0.0125 <0.0125 <0.0128
Lab Sample ID L1704701-01 L1704701-02
Date Collected 2/8/2024 2/8/2024 2/8/2024 2/8/2024
Client Sample ID
L1704701-03 L1704701-04
B-1-11 B-2-10.5 B-3-9.5 B-4-11
Page 1 of 2
Table 1 - VOCs and Petroleum Hydrocarbons in Soil
First Step House - 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units RSL
Residential
RSL
Industrial ISL Tier 1 Result Q Result Q Result Q Result Q
Lab Sample ID L1704701-01 L1704701-02
Date Collected 2/8/2024 2/8/2024 2/8/2024 2/8/2024
Client Sample ID
L1704701-03 L1704701-04
B-1-11 B-2-10.5 B-3-9.5 B-4-11
METHYLENE CHLORIDE 8260B mg/kg 57 1000 NE NE <0.203 <0.00627 <0.00624 <0.00640
4-METHYL-2-PENTANONE (MIBK)8260B mg/kg 33000 140000 NE NE <0.406 <0.0125 J3 <0.0125 J3 <0.0128 J3
METHYL TERT-BUTYL ETHER 8260B mg/kg 47 210 0.3 0.3 <0.0406 <0.00125 <0.00125 <0.00128
NAPHTHALENE 8260B mg/kg 2 8.6 51 51 <0.203 <0.00627 <0.00624 <0.00640
N-PROPYLBENZENE 8260B mg/kg 3800 24000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
STYRENE 8260B mg/kg 6000 35000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,1,1,2-TETRACHLOROETHANE 8260B mg/kg 2 8.8 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,1,2,2-TETRACHLOROETHANE 8260B mg/kg 0.6 2.7 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,1,2-TRICHLOROTRIFLUOROETHANE 8260B mg/kg 6700 28000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
TETRACHLOROETHENE 8260B mg/kg 24 100 NE NE <0.0406 <0.00125 <0.00125 <0.00128
TOLUENE 8260B mg/kg 4900 47000 9 25 <0.203 <0.00627 0.00166 J <0.00640
1,2,3-TRICHLOROBENZENE 8260B mg/kg 63 930 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,2,4-TRICHLOROBENZENE 8260B mg/kg 24 110 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,1,1-TRICHLOROETHANE 8260B mg/kg 8100 36000 NE NE <0.0406 <0.00125 J3 J4 <0.00125 J3 J4 <0.00128 J3 J4
1,1,2-TRICHLOROETHANE 8260B mg/kg 1.1 5 NE NE <0.0406 <0.00125 <0.00125 <0.00128
TRICHLOROETHENE 8260B mg/kg 0.94 6 NE NE <0.0406 <0.00125 <0.00125 <0.00128
TRICHLOROFLUOROMETHANE 8260B mg/kg 23000 350000 NE NE <0.203 <0.00627 <0.00624 <0.00640
1,2,3-TRICHLOROPROPANE 8260B mg/kg 0.0051 0.11 NE NE <0.101 <0.00313 <0.00312 <0.00320
1,2,4-TRIMETHYLBENZENE 8260B mg/kg 300 1800 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,2,3-TRIMETHYLBENZENE 8260B mg/kg 340 2000 NE NE <0.0406 <0.00125 <0.00125 <0.00128
1,3,5-TRIMETHYLBENZENE 8260B mg/kg 270 1500 NE NE <0.0406 <0.00125 <0.00125 <0.00128
VINYL CHLORIDE 8260B mg/kg 0.059 1.7 NE NE <0.0406 <0.00125 <0.00125 <0.00128
XYLENES, TOTAL 8260B mg/kg 580 2500 142 142 <0.122 <0.00376 0.000628 J <0.00384
Qualifiers (Q):
J4: The sample matrix interfered with the ability to make any accurate determination; spike value is high.
NE:Not Established.<:Less than Reported Detection Limit (RDL).
mg/kg:Milligrams per kilogram.
Color shaded value exceeds screening level.
J: The identification of the analyte is acceptable; the reported value is an estimate.
J3: The associated batch QC was outside the established quality control range for
EPA RSL: Environmental Protection Agency Regional Screening Levels for soil at residential
(Res.) and industrial (Ind.) properties (November 2023; TR=1E-06; THQ=1.0).
Utah's Initial Screening Levels (ISLs) and risk-based Tier 1 Screening Levels (Tier 1) for
petroleum releases at leaking underground storage tank sites
Bold value exceeds Method Detection Limit (MDL).
Page 2 of 2
Table 2 - VOCs and Petroleum Hydrocarbons in Groundwater
First Step House - 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units MCL VISL
Residential
VISL
Commercial ISL Tier 1 UGWQS Result Q Result Q Result Q Result Q
TPH-GRO 8260B mg/l NE NE NE 1 10 NE <0.500 <0.500 <0.500 <0.500
TPH-DRO 3511/8015 mg/l NE NE NE 1 10 NE 10.7 0.0537 B J 0.442 <0.200
TRPH 1664A mg/l NE NE NE 10 10 NE <5.68 1.3 J 2.47 J 43.3 J
ACETONE 8260B mg/l NE 22500 94500 NE NE NE <0.0500 <0.0500 <0.0500 <0.0500
ACROLEIN 8260B mg/l NE 0.00418 0.0176 NE NE NE <0.0500 J4 <0.0500 J4 <0.0500 J4 <0.0500 J4
ACRYLONITRILE 8260B mg/l NE 0.00732 0.032 NE NE NE <0.0100 <0.0100 <0.0100 <0.0100
BENZENE 8260B mg/l 0.005 0.00159 0.00693 0.005 0.3 0.005 <0.00100 <0.00100 <0.00100 <0.00100
BROMOBENZENE 8260B mg/l NE 0.62 2.6 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
BROMODICHLOROMETHANE 8260B mg/l 0.08 0.000876 0.00382 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
BROMOFORM 8260B mg/l 0.08 0.117 0.51 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
BROMOMETHANE 8260B mg/l NE 0.0174 0.073 NE NE NE <0.00500 <0.00500 <0.00500 <0.00500
N-BUTYLBENZENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
SEC-BUTYLBENZENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
TERT-BUTYLBENZENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
CARBON TETRACHLORIDE 8260B mg/l 0.005 0.000415 0.00181 NE NE 0.005 <0.00100 <0.00100 <0.00100 <0.00100
CHLOROBENZENE 8260B mg/l 0.1 0.41 1.72 NE NE 0.1 <0.00100 <0.00100 <0.00100 <0.00100
CHLORODIBROMOMETHANE 8260B mg/l 0.08 NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
CHLOROETHANE 8260B mg/l NE 23 96.5 NE NE NE <0.00500 <0.00500 <0.00500 <0.00500
2-CHLOROETHYL VINYL ETHER 8260B mg/l NE NE NE NE NE NE <0.0500 <0.0500 <0.0500 <0.0500
CHLOROFORM 8260B mg/l 0.08 0.000814 0.00355 NE NE NE <0.00500 <0.00500 <0.00500 <0.00500
CHLOROMETHANE 8260B mg/l NE 0.26 1.09 NE NE NE <0.00250 <0.00250 <0.00250 <0.00250
2-CHLOROTOLUENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
4-CHLOROTOLUENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,2-DIBROMO-3-CHLOROPROPANE 8260B mg/l 0.0002 0.0000281 0.00034 NE NE 0.0002 <0.00500 <0.00500 <0.00500 <0.00500
1,2-DIBROMOETHANE 8260B mg/l 0.00005 0.000176 0.000769 NE NE 0.00005 <0.00100 <0.00100 <0.00100 <0.00100
DIBROMOMETHANE 8260B mg/l NE 0.124 0.521 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,2-DICHLOROBENZENE 8260B mg/l 0.6 2.66 11.2 NE NE 0.6 <0.00100 <0.00100 <0.00100 <0.00100
1,3-DICHLOROBENZENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,4-DICHLOROBENZENE 8260B mg/l 0.075 0.00259 0.0113 NE NE 0.075 <0.00100 <0.00100 <0.00100 <0.00100
DICHLORODIFLUOROMETHANE 8260B mg/l NE 0.00744 0.0312 NE NE NE <0.00500 <0.00500 <0.00500 <0.00500
1,1-DICHLOROETHANE 8260B mg/l NE 0.00764 0.0334 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,2-DICHLOROETHANE 8260B mg/l 0.005 0.00224 0.00978 NE NE 0.005 <0.00100 <0.00100 <0.00100 <0.00100
1,1-DICHLOROETHENE 8260B mg/l 0.007 0.195 0.821 NE NE 0.007 <0.00100 <0.00100 <0.00100 <0.00100
CIS-1,2-DICHLOROETHENE 8260B mg/l 0.07 NE NE NE NE 0.07 <0.00100 <0.00100 <0.00100 <0.00100
TRANS-1,2-DICHLOROETHENE 8260B mg/l 0.1 0.109 0.457 NE NE 0.1 <0.00100 <0.00100 <0.00100 <0.00100
1,2-DICHLOROPROPANE 8260B mg/l 0.005 0.00658 0.0287 NE NE 0.005 <0.00100 <0.00100 <0.00100 <0.00100
1,1-DICHLOROPROPENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,3-DICHLOROPROPANE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
CIS-1,3-DICHLOROPROPENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
Lab Sample ID
Client Sample ID B-4
Date Collected 01/24/2024 01/24/2024 01/23/2024 01/24/2024
L1704701-05 L1704701-06 L1704701-07 L1704701-08
B-1 B-2 B-3
Page 1 of 3
Table 2 - VOCs and Petroleum Hydrocarbons in Groundwater
First Step House - 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units MCL VISL
Residential
VISL
Commercial ISL Tier 1 UGWQS Result Q Result Q Result Q Result Q
Lab Sample ID
Client Sample ID B-4
Date Collected 01/24/2024 01/24/2024 01/23/2024 01/24/2024
L1704701-05 L1704701-06 L1704701-07 L1704701-08
B-1 B-2 B-3
TRANS-1,3-DICHLOROPROPENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
2,2-DICHLOROPROPANE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
DI-ISOPROPYL ETHER 8260B mg/l NE 6.97 29.3 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
ETHYLBENZENE 8260B mg/l 0.7 0.00349 0.0152 0.7 4 0.7 <0.00100 <0.00100 <0.00100 <0.00100
HEXACHLORO-1,3-BUTADIENE 8260B mg/l NE 0.000303 0.00132 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
ISOPROPYLBENZENE 8260B mg/l NE 0.887 3.73 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
P-ISOPROPYLTOLUENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
2-BUTANONE (MEK)8260B mg/l NE 2240 9410 NE NE NE <0.0100 <0.0100 <0.0100 <0.0100
METHYLENE CHLORIDE 8260B mg/l 0.005 0.763 9.23 NE NE 0.005 <0.00500 <0.00500 <0.00500 <0.00500
4-METHYL-2-PENTANONE (MIBK)8260B mg/l NE 555 2330 NE NE NE <0.0100 <0.0100 <0.0100 <0.0100
METHYL TERT-BUTYL ETHER 8260B mg/l NE 0.45 1.97 0.2 0.2 NE <0.00100 <0.00100 <0.00100 <0.00100
NAPHTHALENE 8260B mg/l NE 0.00459 0.0201 0.7 0.7 NE <0.00500 <0.00500 <0.00500 <0.00500
N-PROPYLBENZENE 8260B mg/l NE 2.43 10.2 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
STYRENE 8260B mg/l 0.1 9.28 39 NE NE 0.1 <0.00100 <0.00100 <0.00100 <0.00100
1,1,1,2-TETRACHLOROETHANE 8260B mg/l NE 0.00371 0.0162 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,1,2,2-TETRACHLOROETHANE 8260B mg/l NE 0.00323 0.0141 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,1,2-TRICHLOROTRIFLUOROETHANE 8260B mg/l NE 0.242 1.02 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
TETRACHLOROETHENE 8260B mg/l 0.005 0.0149 0.0652 NE NE 0.005 <0.00100 <0.00100 <0.00100 <0.00100
TOLUENE 8260B mg/l 1 19.2 80.7 1 3 1 <0.00100 <0.00100 <0.00100 <0.00100
1,2,3-TRICHLOROBENZENE 8260B mg/l NE NE NE NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,2,4-TRICHLOROBENZENE 8260B mg/l 0.07 0.0359 0.151 NE NE 0.07 <0.00100 <0.00100 <0.00100 <0.00100
1,1,1-TRICHLOROETHANE 8260B mg/l 0.2 7.42 31.1 NE NE 0.2 <0.00100 <0.00100 <0.00100 <0.00100
1,1,2-TRICHLOROETHANE 8260B mg/l 0.005 0.00521 0.0228 NE NE 0.005 <0.00100 <0.00100 <0.00100 <0.00100
TRICHLOROETHENE 8260B mg/l 0.005 0.00119 0.00743 NE NE 0.005 <0.00100 <0.00100 <0.00100 <0.00100
TRICHLOROFLUOROMETHANE 8260B mg/l NE NE NE NE NE NE <0.00500 <0.00500 <0.00500 <0.00500
1,2,3-TRICHLOROPROPANE 8260B mg/l NE 0.0223 0.0937 NE NE NE <0.00250 <0.00250 <0.00250 <0.00250
1,2,4-TRIMETHYLBENZENE 8260B mg/l NE 0.248 1.04 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
1,2,3-TRIMETHYLBENZENE 8260B mg/l NE 0.351 1.47 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
Page 2 of 3
Table 2 - VOCs and Petroleum Hydrocarbons in Groundwater
First Step House - 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units MCL VISL
Residential
VISL
Commercial ISL Tier 1 UGWQS Result Q Result Q Result Q Result Q
Lab Sample ID
Client Sample ID B-4
Date Collected 01/24/2024 01/24/2024 01/23/2024 01/24/2024
L1704701-05 L1704701-06 L1704701-07 L1704701-08
B-1 B-2 B-3
1,3,5-TRIMETHYLBENZENE 8260B mg/l NE 0.175 0.733 NE NE NE <0.00100 <0.00100 <0.00100 <0.00100
VINYL CHLORIDE 8260B mg/l 0.002 0.000147 0.00245 NE NE 0.002 <0.00100 <0.00100 <0.00100 <0.00100
XYLENES, TOTAL 8260B mg/l 10 0.385 1.62 10 10 10 <0.00300 <0.00300 <0.00300 <0.00300
J4: The sample matrix interfered with the ability to make any accurate determination; spike value is high.
J: The identification of the analyte is acceptable; the reported value is an estimate.
B: The same analyte is found in the associated blank.
NE:Not Established.<:Less than Reported Detection Limit (RDL).mg/l:Milligrams per liter.
Bold value exceeds Method Detection Limit (MDL).Color shaded value exceeds screening level.
EPA VISL: Target Groundwater Concentration (TGC) Vapor Intrusion Screening Level (VISL); April 2023.
Qualifiers (Q):
EPA RSL: Environmental Protection Agency Regional Screening level for drinking water (April 2023).
EPA MCL: Environmental Protection Agency Maximum Contaminant Level for drinking water (May 2023).
UDEQ: Utah Department of Environmental Quality's Initial Screening Levels (ISLs) and risk-based Tier 1 Screening Levels (Tier 1) for
petroleum hydrocarbons in groundwater at underground storage tank sites.
UGWQS:Utah Ground Water Quality Standards.
Page 3 of 3
Table 3 - VOCs in Soil Gas
First Step House, 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units VISL
Residential
VISL
Commercial Result Q Result Q
ACETONE TO-15 µg/m3 1070000 4510000 23.6 56.3
ALLYL CHLORIDE TO-15 µg/m3 15.6 68.1 <0.626 <0.626
BENZENE TO-15 µg/m3 12 52.4 <0.639 <0.639
BENZYL CHLORIDE TO-15 µg/m3 1.91 8.34 <1.04 <1.04
BROMODICHLOROMETHANE TO-15 µg/m3 2.53 11 <1.34 <1.34
BROMOFORM TO-15 µg/m3 85.1 372 <6.21 <6.21
BROMOMETHANE TO-15 µg/m3 174 730 <0.776 <0.776
1,3-BUTADIENE TO-15 µg/m3 3.12 13.6 <4.43 <4.43
CARBON DISULFIDE TO-15 µg/m3 24300 102000 1.75 1.54
CARBON TETRACHLORIDE TO-15 µg/m3 15.6 68.1 <1.26 <1.26
CHLOROBENZENE TO-15 µg/m3 1740 7300 <0.924 <0.924
CHLOROETHANE TO-15 µg/m3 348000 1460000 <0.528 <0.528
CHLOROFORM TO-15 µg/m3 4.07 17.8 <0.973 <0.973
CHLOROMETHANE TO-15 µg/m3 3130 13100 0.539 0.853
2-CHLOROTOLUENE TO-15 µg/m3 NE NE <1.03 <1.03
CYCLOHEXANE TO-15 µg/m3 209000 876000 <0.689 <0.689
CHLORODIBROMOMETHANE TO-15 µg/m3 NE NE <1.70 <1.70
1,2-DIBROMOETHANE TO-15 µg/m3 0.156 0.681 <1.54 <1.54
1,2-DICHLOROBENZENE TO-15 µg/m3 6950 29200 <1.20 <1.20
1,3-DICHLOROBENZENE TO-15 µg/m3 NE NE <1.20 <1.20
1,4-DICHLOROBENZENE TO-15 µg/m3 8.51 37.2 <1.20 <1.20
1,2-DICHLOROETHANE TO-15 µg/m3 3.6 15.7 <0.810 <0.810
1,1-DICHLOROETHANE TO-15 µg/m3 58.5 256 <0.802 3.37
1,1-DICHLOROETHENE TO-15 µg/m3 6950 29200 <0.793 <0.793
CIS-1,2-DICHLOROETHENE TO-15 µg/m3 NE NE <0.793 <0.793
TRANS-1,2-DICHLOROETHENE TO-15 µg/m3 NE NE <0.793 <0.793
1,2-DICHLOROPROPANE TO-15 µg/m3 25.3 110 <0.924 <0.924
CIS-1,3-DICHLOROPROPENE TO-15 µg/m3 NE NE <0.908 <0.908
TRANS-1,3-DICHLOROPROPENE TO-15 µg/m3 NE NE <0.908 <0.908
1,4-DIOXANE TO-15 µg/m3 18.7 81.8 <2.27 <2.27
ETHANOL TO-15 µg/m3 NE NE 173 187
ETHYLBENZENE TO-15 µg/m3 37.4 164 <0.867 1.4
4-ETHYLTOLUENE TO-15 µg/m3 NE NE <0.982 <0.982
TRICHLOROFLUOROMETHANE TO-15 µg/m3 NE NE 1.43 2.74
Date Collected 1/25/2024 1/25/2024
Lab Sample ID L1705083-01 L1705083-02
Client Sample ID SV-1 SV-2
Table 3 - VOCs in Soil Gas
First Step House, 273 East 800 South, Salt Lake City, Utah
Terracon Project No. 61247015
Analyte Method Units VISL
Residential
VISL
Commercial Result Q Result Q
Date Collected 1/25/2024 1/25/2024
Lab Sample ID L1705083-01 L1705083-02
Client Sample ID SV-1 SV-2
DICHLORODIFLUOROMETHANE TO-15 µg/m3 3480 14600 2.43 2.7
1,1,2-TRICHLOROTRIFLUOROETHANETO-15 µg/m3 174000 730000 <1.53 <1.53
1,2-DICHLOROTETRAFLUOROETHANETO-15 µg/m3 NE NE <1.40 <1.40
HEPTANE TO-15 µg/m3 13900 58400 <0.818 0.945
HEXACHLORO-1,3-BUTADIENE TO-15 µg/m3 4.25 18.6 <6.73 <6.73
N-HEXANE TO-15 µg/m3 24300 102000 2.89 <2.22
ISOPROPYLBENZENE TO-15 µg/m3 13900 58400 <0.983 <0.983
METHYLENE CHLORIDE TO-15 µg/m3 3380 40900 23 2.44
METHYL BUTYL KETONE TO-15 µg/m3 1040 4380 <5.11 <5.11
2-BUTANONE (MEK)TO-15 µg/m3 174000 730000 <3.69 5.66
4-METHYL-2-PENTANONE (MIBK)TO-15 µg/m3 104000 438000 <5.12 <5.12
METHYL METHACRYLATE TO-15 µg/m3 24300 102000 <0.819 <0.819
METHYL TERT-BUTYL ETHER TO-15 µg/m3 360 1570 <0.721 <0.721
NAPHTHALENE TO-15 µg/m3 2.75 12 <3.30 <3.30
2-PROPANOL TO-15 µg/m3 6950 29200 25.6 18.4
PROPENE TO-15 µg/m3 104000 438000 <2.15 3.79
STYRENE TO-15 µg/m3 34800 146000 <0.851 <0.851
1,1,2,2-TETRACHLOROETHANE TO-15 µg/m3 1.61 7.05 <1.37 <1.37
TETRACHLOROETHENE TO-15 µg/m3 360 1570 <1.36 8.01
TETRAHYDROFURAN TO-15 µg/m3 69500 292000 <0.590 <0.590
TOLUENE TO-15 µg/m3 174000 730000 2.88 3.2
1,2,4-TRICHLOROBENZENE TO-15 µg/m3 69.5 292 <4.66 <4.66
1,1,1-TRICHLOROETHANE TO-15 µg/m3 174000 730000 <1.09 3.2
1,1,2-TRICHLOROETHANE TO-15 µg/m3 5.85 25.6 <1.09 <1.09
TRICHLOROETHENE TO-15 µg/m3 15.9 99.7 <1.07 <1.07
1,2,4-TRIMETHYLBENZENE TO-15 µg/m3 2090 8760 <0.982 <0.982
1,3,5-TRIMETHYLBENZENE TO-15 µg/m3 2090 8760 <0.982 <0.982
2,2,4-TRIMETHYLPENTANE TO-15 µg/m3 NE NE <0.934 <0.934
VINYL CHLORIDE TO-15 µg/m3 5.59 92.9 <0.511 <0.511
VINYL BROMIDE TO-15 µg/m3 2.92 12.8 <0.875 <0.875
VINYL ACETATE TO-15 µg/m3 6950 29200 <2.22 <2.22
XYLENES, TOTAL TO-15 µg/m3 3480 14600 3.55 5.95
M&P-XYLENE TO-15 µg/m3 3480 14600 2.67 4.47
O-XYLENE TO-15 µg/m3 3480 14600 0.871 1.46
NE:Not Established.<:Less than Reported Detection Limit (RDL).µg/m3:micrograms per cubic meter.
Bold value exceeds Method Detection Limit (MDL).
Qualifiers (Q):
EPA VISL: Environmental Protection Agency Target Sub-Slab and Near-source Soil Gas Concentration
(TSSNSGC) Vapor Intrusion Screening Level (VISL); November 2023.