Wash. Rev. Code § 35.21.422
Any city, located within a county with a population of two hundred ten thousand or more west of the Cascades, owning and operating a public utility and having facilities for the distribution of electricity located outside its city limits, may provide for the support of cities, towns, counties and taxing districts in which such facilities are located, and enter into contracts with such county therefor. Such contribution shall be based upon the amount of retail sales of electricity, other than to governmental agencies, made by such city in the areas of such cities, towns, counties or taxing districts in which such facilities are located, and shall be divided among them on the same basis as taxes on real and personal property therein are divided.
RCW 35.21.422
Purpose-Captions not law-1991 c 363: See notes following RCW 2.32.180.