The Utah state law explains it this way:
54-8a-7. Notice of damage — Repairs. (https://le.utah.gov/xcode/Title54/Chapter8A/54-8a-S7.html)
(1) An excavator performing an excavation that results in contact or damage to a facility shall:
(a) provide notice of the contact or damage including the location and nature of any damage immediately to the operator;
(b) allow the operator reasonable time when considering the safety of the area, and the availability of materials, labor, or equipment, to make or coordinate necessary repairs before completing the excavation in the immediate area of the facility; and
(c) delay any backfilling in the immediate area of the contacted or damaged facility until the operator authorizes the excavator to resume backfilling.
(2) After receiving notification of contact or damage to a facility, the operator, or qualified personnel authorized by the operator, shall:
(a) expedite a response to examine the contacted or damaged facility; and
(b) make or coordinate necessary repairs to the contacted or damaged facility within eight business hours or notify the excavator that the repairs will take longer than eight business hours due to safety or availability of materials, labor, or equipment.
(3) (a) An excavator that is responsible for an excavation where any contact or damage to a facility results in the discharge of electricity or escape of any flammable, toxic, or corrosive gas or liquid, or that endangers life, health, or property shall:
(i) immediately notify:
(A) emergency responders, including 911 services; and
(B) the facility operator; and
(ii) take reasonable measures to protect the excavator, other persons, property, and the environment until the operator or emergency responders arrive.