Wash. Rev. Code § 36.96.020
On or before June 1st of 1980, and on or before June 1st of every year thereafter, each county auditor shall search available records and notify the county legislative authority if any special purpose districts located wholly or partially within the county appear to be inactive. If the territory of any special purpose district is located within more than one county, the legislative authorities of all other counties within whose boundaries such a special purpose district lies shall also be notified by the county auditor. However, the authority to dissolve such a special purpose district as provided by this chapter shall rest solely with the legislative authority of the county which contains the greatest geographic portion of such special purpose district.
RCW 36.96.020