DERR-2024-008336

Dominion Energy Services, Inc.
120 Tredegar Street, Richmond, VA 23219
DominionEnergy.com

VIA EMAIL

April 16, 2024

Kelsey Robinson
Utah Department of Environmental Quality
Division of Environmental Response and Remediation
168 North 1950 West
Salt Lake City, Utah 84116

RE: Environmental Covenant Questar Gas Salt Lake Operations Center –
Sprinkler Line Repairs & Sign Installation

Dear Ms. Robinson:

Questar Gas Company (Questar), d/b/a Dominion Energy Utah, is providing notification to
the Division of Environmental Response and Remediation (DERR) of two projects it intends
to conduct within the Environmental Covenant Boundary at its Salt Lake Operations Center
(Figures 1 and 2). The projects include routine sprinkler system repairs and installation of
updated facility signage.

Questar anticipates that the sprinkler system repairs will be completed by a 3rd party
landscape, construction, and maintenance contractor and/or Questar personnel during the
summer months of 2024. The work will require shallow soil trenching and excavation(s) to
an anticipated maximum depth of 18-inches below ground surface to expose sprinkler system
components and perform subsequent repairs.

Additionally, a concrete pad will be installed to accommodate an updated sign near the
facility’s eastern entrance. An existing concrete footing will be removed and an
approximately a 2-foot by 3-foot area will be excavated to 12-inches below ground surface
and a new concrete pad will be installed for an updated sign. The proposed excavation is
shown on Figure 2.

A Questar representative will lead a Contractor Health Hazard Advisory (CHHA) meeting
with all contractor personnel to review the property’s history, and potential health hazards
for the day’s tasks prior to any work requiring ground disturbance. All contractor personnel
will be required to attend the CHHA meeting and verify that they understand the information
provided. A Questar representative will remain onsite for the duration of the work to
perform continuous environmental monitoring. The Questar representative will visually
inspect excavated soils for signs of contamination (staining, discoloration, indication of free
product or residuals) and conduct atmospheric monitoring with a field-calibrated
Kelsey Robinson
April 16, 2024
Page 2 of 4
photoionization detector (PID), as necessary.

The Questar representative will stop work if Action Levels specified in the Environmental,
Health, Safety and Site Management Plan (2.50 parts per million-volt) are exceeded. Work
will re-commence following the implementation of exposure controls and reduction in
exposure to contaminants in the breathing zone to below prescribed Action Levels. Upon
completion of the work, Questar will submit a report to DERR to provide information related
to any impacted materials encountered, laboratory analytical results, and waste generation
and disposal.

If you have any questions or concerns related to this notice, please contact Kris Benson at
801-349-6950 or [e-mail].

Sincerely,

Adam Plonsky
Manager, BU Environmental Compliance

Kelsey Robinson
April 16, 2024
Page 3 of 4

Figure 1 – Environmental Covenant Area
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April 16, 2024
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Figure 2 – Potential Sprinkler Repair Areas within Covenant Area