RCW 80.28.130

Whenever the commission finds, after hearing had upon its own motion or upon complaint, that repairs or improvements, to, or changes in, any gas plant, electrical plant, system of sewerage, water system, or thermal energy system ought to be made, or that any additions or extensions should reasonably be made thereto, in order to promote the security or convenience of the public or employees, or in order to secure adequate service or facilities for manufacturing, distributing or supplying gas, electricity, wastewater company services, water, or thermal energy, the commission may enter an order directing that such reasonable repairs, improvements, changes, additions or extensions of such gas plant, electrical plant, system of sewerage, water system, or thermal energy system be made. The commission may require a large combination utility as defined in RCW 80.86.010 to incorporate any existing pipeline safety and replacement plans under this section into an integrated system plan established under RCW 80.86.020.