Wash. Rev. Code § 80.28.275
A water company or a wastewater company assuming responsibility for a water system or system of sewerage that is not in compliance with state or federal requirements, and its agents and employees, are immune from lawsuits or causes of action, based on noncompliance with state or federal requirements, which predate the date of assuming responsibility and continue after the date of assuming responsibility, provided that the water company or wastewater company has submitted and is complying with a plan and schedule of improvements approved by the department of health or the department of ecology, as appropriate to the agencies' jurisdiction. This immunity expires on the earlier of the date the plan of improvements is completed or four years from the date of assuming responsibility. This immunity does not apply to intentional injuries, fraud, or bad faith and is subject to the provisions of law governing clean water as referenced by the commission by rule.
RCW 80.28.275
Findings-Purpose-Limitation of chapter-Effective date- 2011 c 214 : See notes following RCW 80.04.010.
Findings-Intent-1994 c 292: See note following RCW 57.04.050.