Utah Code Ann. § 11-42-106
(1) A person who contests an assessment or any proceeding to designate an assessment area or levy an assessment may commence a civil action against the local entity to:
(2)
(b)
(i) Except as provided in Subsection (2)(b)(ii), an action under Subsection (1) may not be commenced against and a summons relating to the action may not be served on the local entity more than 60 days after the effective date of the:
(ii) The period for commencing an action and serving a summons under Subsection (2)(b)(i) is 30 days if the designation resolution, assessment resolution, or amended resolution was:
(3)
(a) An action under Subsection (1) is the exclusive remedy of a person who:
(c)
(5) After the expiration of the period referred to in Subsection (2)(b):
(6)
(b)