DERR-2024-006545

February 7, 2024

Scope of Work for Additional Off-Site Groundwater Assessment
GE North Salt Lake
130 E 1100 North
North Salt Lake, Utah

Groundwater sampling was completed during five (5) separate quarters on the adjoining
property in 2022 and 2023 at 50 E 1100 North, located approximately 200 feet west of the
Site, which is owned by DS Investments and occupied by 3D Storage and Advanced Metal
Finishing. Nine (9) consecutive quarters of groundwater sampling has been completed on
the General Electric (GE) Site. Since concentrations of specific VOC constituents were
detected in groundwater near the western property boundary above applicable criteria,
additional off-site delineation has been requested by DERR.

Based on individual constituent molar fraction analysis, the chlorinated solvent
constituents (e.g., trichloroethylene {TCE}) observed in offsite wells (“A-1 and A-2”) appear to
be from a separate offsite source unrelated to the GE North Salt Lake Site. Therefore, the
primary purpose of the proposed off-site groundwater assessment is to support the
delineation of 1,4-Dioxane in off-site, downgradient groundwater.

The assessment will include the installation of a total of eleven (11) permanently
constructed groundwater wells including four (4) on adjoining properties (3D Storage,
Advanced Metal Finishing, and Accurate Cut Carbide) and seven (7) permanently
constructed groundwater monitoring wells along North Main Street to the west and E 1100
North (W 2600 S) to the northwest of the Site 1. Activities will be completed in general
accordance with the Sampling and Analysis Plan (SAP) and Quality Assurance Project Plan
(QAPP) competed in July 2021 and approved by DERR in August 2021.

HASP
WSP will prepare the project Site-Specific Health and Safety Plan (HASP) prior to initiating
the field activities. The HASP will address potential worker safety risks based on previous
site assessments and to address risks associated with the assessment activities proposed in
the right-of-way. The HASP will include a requirement that only WSP and its subcontractors
who are properly trained individuals are permitted to conduct field activities. Site personnel
will be required to have valid HAZWOPER certifications in accordance with OSHA 29 CFR
1910.120. The HASP will also require the subcontractor’s personnel to adhere to WSP’s and
GE’s health and safety contractor policies and OSHA, state, local, and applicable federal
laws and regulations. Additionally, WSP will work with each contractor/vendor to
thoroughly plan the field work tasks, sequence, and sampling to protect human health and

1 Installation of groundwater monitoring wells and sampling is dependent on GE &
WSP being permitted access to the property by each property owner, through
preparation of an access agreement

GE North Salt Lake
Off-Site, Downgradient Groundwater Assessment

WSP
February 7, 2024
Page 2
the environment. WSP will review required Contractor submittals (permits, health and
safety plan, project execution plan, and final project schedule) prior to mobilization.

Off-Site Well Installation and Sampling – Right of Way
In preparation of the field work, WSP will manage communications with the City of North
Salt Lake to obtain all required permits and authorizations to complete work along North
Main Street and E 1100 North (W 2600 S). Since these right-of-ways include vehicular traffic
and access to adjoining properties, a professional traffic control company will be required,
which will be procured by WSP.

WSP will notify Utah One Call to mark utilities around the periphery of the area prior to
conducting the well installation activities. The proposed locations will be cleared by a
private utility locator using ground penetrating radar (GPR). Utilities in the vicinity of the
well locations will be marked and boring and monitoring locations adjusted in the field, as
necessary. As an additional precaution, WSP’s drilling subcontractor will utilize a hand
auger for the top two feet of the locations in the vicinity of utilities identified by GPR. WSP
personnel will be on Site during the clearance activities.

Eleven (11) permanently constructed groundwater wells will be advanced in the right-of-
ways and adjoining properties to further delineate off-site, downgradient groundwater in
the area. The proposed well locations are depicted on Figure 1. Each well will be advanced
with 4.25-inch interior diameter hollow stem augers into the upper groundwater bearing
unit, which is anticipated to be encountered between 10 feet and 20 feet bgs. Augers will
be decontaminated between well locations. The wells will be constructed of 2-inch PVC
with a 5-foot to 10-foot 0.010-inch slotted screen section. The annular space around the
well screen will be filled with clean filter pack sand to approximately two feet above the
top of the screen, and a hydrated bentonite seal with a minimum thickness of two feet will
be placed above the filter pack. The remaining annular space will be sealed with a Portland
Type I bentonite/cement slurry to the ground surface. Each permanent monitoring well will
be completed with a flush mounted well vault and bolted manway cover, monitoring well
tag, and locking well cap. Once the grout and bentonite seals are set, approximately 24
hours after installation, the wells will be developed using a pump with dedicated tubing or
disposable bailer until the water is clear or the well is purged dry.

Groundwater samples from the existing and new wells will be collected using low flow
techniques, with a peristaltic pump with dedicated tubing attached to a flow-through cell
with probes to monitor water quality parameters. The water quality parameters will include
temperature, pH, specific conductance, oxidation-reduction potential (ORP), and dissolved
oxygen (DO). Turbidity will also be monitored during purging. Turbidity will be measured
with a LaMotte™ 2020 (or similar) turbidity meter. The probes/meters will be calibrated
according to manufacturer specifications for each parameter prior to sampling, and on a
daily basis thereafter. The pumping rate will be maintained between 100 and 300 milliliters
per minute (mL/min) to maintain minimal water level drawdown and to minimize

GE North Salt Lake
Off-Site, Downgradient Groundwater Assessment

WSP
February 7, 2024
Page 3
suspension of fine-grained sediments and aeration of the water. The water level in the well
will be monitored to document that drawdown does not increase during purging.
Drawdown and water quality parameters will be monitored and recorded approximately
every three to five minutes. Water quality parameters will be documented on WSP
groundwater sampling forms.

Groundwater samples will be collected when monitoring parameters have stabilized for
three successive readings, taken at 3 to 5-minute intervals. Stability is achieved when
readings are within ± 0.2 standard units (s.u.) for pH, ± 3 percent for specific conductance, ±
20 millivolts (mV) for ORP, and ± 10 percent or ± 2.0 milligrams per milliliter (mg/ml) for DO.
Stabilization of turbidity will occur when three successive turbidity values are within 10
percent for values greater than 10 nephelometric turbidity units (NTU) or if three turbidity
values are less than 10 NTU, turbidity will be considered stabilized. Sampling will be
performed by disconnecting the down hole tubing, prior to the flow-through cell, and
placing it into the appropriate certified clean laboratory sample containers. New disposable
sample tubing will be used at each well. Groundwater samples will be collected from each
of the wells using the dedicated tubing. Groundwater samples will be submitted to
Eurofins Laboratories, Inc. A summary of the proposed number of wells, number of water
samples, and laboratory analyses is provided in Table 1.

TABLE 1 – OFF-SITE GROUNDWATER ANALYTICAL SUMMARY
Assessment Areas Number of
Wells
Number of
Water Samples Laboratory Analysis
50 E 1100 N
(W 2600 S) A-1 & A-2 2 8260-SIM or 8270-SIM (1,4-
Dioxane only)
50 E 1100 N
(W 2600 S) 2 2 8260-SIM or 8270-SIM (1,4-
Dioxane only)
N Main St. 4 4 8260-SIM or 8270-SIM (1,4-
Dioxane only)
DS Investments (50 E 1100
North, 1050 N Main St) 3 3 8260-SIM or 8270-SIM (1,4-
Dioxane only)
Accurate Cut Carbide
(990 N Main St) 1 1 8260-SIM or 8270-SIM (1,4-
Dioxane only)
George & Ruthann Fisher
Family LLC 1 1 8260-SIM or 8270-SIM (1,4-
Dioxane only)

GE North Salt Lake
Off-Site, Downgradient Groundwater Assessment

WSP
February 7, 2024
Page 4

Soil cuttings, development water, purge water, decontamination fluids, personal protective
equipment (PPE), disposable sampling material, and other investigation-derived waste
(IDW) will be placed in labeled 55-gallon steel drums, and temporarily staged at the various
drilling locations on the Site.

WSP will submit a report summarizing the field activities and analytical results. The report
will be submitted to GE within 30 days of receipt of the laboratory analytical results. The
report will include a description of field methodologies, boring logs, Site lithology,
analytical results, a photographic log, and Site figures.
MW-15
MW-1
MW-16
MW-17
MW-18
MW-3
MW-19
MW-4
MW-7
MW-2
MW-8
MW-22
MW-20
MW-21
MW-23
MW-6
MW-5
MW-14
MW-13MW-10
MW-11
MW-12
E 1100 North

Ra
i
l
r
o
a
d

T
r
a
c
k
s
Ra
i
l
r
o
a
d

T
r
a
c
k
s
N
M
a
i
n

S
t
r
e
e
t
Offsite-A2
Offsite-A1
1100 North Municipal Well
40 E 1100 North
North Salt Lake City
3D Storage/Advanced
Metal Finishing
50 E 1100 North
DS Investments LLC
(Commercial Building)
1050 N Main Street
DS Investments LLC
Accurate Cut Carbide
990 N Main Street
Lee R Nielsen
(5.0*)
(9.6*)
(2.5*)
(4.2*)
(3.1*)
(2.3*)
(NS)
(12.0*)
(16.1*)
(NS)
(2.3*)(18.9*)
(0.7*J)
(0.7*J)
(0.7*J)
(0.7*J)
(0.7*J)
(1.6*)
(3.9*)
(42.8*)
(3.7*)
(1.5*)
(1.0*)
(0.8*)
(Commercial Building)
980 N Main Street
George & Ruthann
Fisher Family LLC
DATE
DESIGNED
PREPARED
REVIEWED
APPROVED
02/07/2024
---
RLB
CLIENT/PROJECT
TITLE
PROJECT NO.REV.FIGURE
1
N
P:
\
I
n
d
y

O
f
f
i
c
e
\
G
E

U
t
a
h
\
S
i
t
e

W
e
s
t
.
d
w
g

-

S
i
t
e

W
e
s
t

-

a
d
d
e
d

s
o
u
t
h

p
r
o
p
e
r
t
y

-

F
e
b
.

0
7
,

2
0
2
4

1
:
1
6
p
m
APPROXIMATE SCALE IN FEET
0 140 280
CONSULTANT NAME
WSP USA Environment & Infrastructure Inc.
CONSULTANT
LEGEND
GENERAL ELECTRIC
130 East 1100 North, North Salt Lake, Utah
BG
BG WDP0033.0006.02
PROPOSED 1,4-DIOXANE OFF-SITE ASSESSMENT
References: Google Earth Pro image dated 06/14/2022.
Approximate Parcel Boundary
Proposed Well Location
Property parcels from Davis County Interactive
Parcel Information App on their website.
Former Facility
Proposed Assessment Area
Monitoring Well Location
Approximate GE Parcel Boundary
(Tenant / Address / Owner)
On-Site 1,4-Dioxane Results, June 2023(3.5*)
Off-Site 1,4-Dioxane Results, July 2023(3.1*)
Notes:
1. * = Result exceeds EPA Regional Screening Level (RSL) limit of 0.46 μg/L.
2. J = Estimated value; ND = Not detected; NS = Not sampled, μg/L = micrograms per liter
3. ** = Result reported above screening level of 0.46 μg/L.