RCW 80.04.150: Remunerative rates cannot be changed without approval.

Whenever the commission shall find, after hearing had upon its own motion or upon complaint as herein provided, that any rate, toll, rental or charge which has been the subject of complaint and inquiry is sufficiently remunerative to the public service company affected thereby, it may order that such rate, toll, rental or charge shall not be changed, altered, abrogated or discontinued, nor shall there be any change in the classification which will change or alter such rate, toll, rental or charge without first obtaining the consent of the commission authorizing such change to be made.