Washington Revised Code Title 36. Counties § 36.115.040. Geographic area covered--Contents--When effective

(1) Agreements among local governments concerning one or more governmental service should be established for a designated geographic area as provided in this section.

(2) A service agreement must describe: (a) The governmental service or services addressed by the agreement; (b) the geographic area covered by the agreement; (c) which local government or local governments are to provide each of the governmental services addressed by the agreement within the geographic area covered by the agreement; and (d) the term of the agreement, if any.

(3) A service agreement becomes effective when approved by: (a) The county legislative authority of each county that includes territory located within the geographic area covered by the agreement; (b) the governing body or bodies of at least a simple majority of the total number of cities that includes territory located within the geographic area covered by the agreement, which cities include at least seventy-five percent of the total population of all cities that includes territory located within the geographic area covered by the agreement; and (c) for each governmental service addressed by the agreement, the governing body or bodies of at least a simple majority of the special districts that include territory located within the geographic area covered by the agreement and which provide the governmental service within such territory. The participants may agree to use another formula. An agreement pursuant to this section shall be effective upon adoption by the county legislative authority following a public hearing.

(4) A service agreement may cover a geographic area that includes territory located in more than a single county.