Wash. Rev. Code § 36.17.040
The salaries of county officers and employees of counties other than counties with a population of less than five thousand may be paid twice monthly out of the county treasury, and the county auditor, for services rendered from the first to the fifteenth day, inclusive, may, not later than the last day of the month, draw a warrant upon the county treasurer in favor of each of such officers and employees for the amount of salary due him or her, and such auditor, for services rendered from the sixteenth to the last day, inclusive, may similarly draw a warrant, not later than the fifteenth day of the following month, and the county legislative authority, with the concurrence of the county auditor, may enter an order on the record journal empowering him or her so to do: PROVIDED, That if the county legislative authority does not adopt the semimonthly pay plan, it, by resolution, shall designate the first pay period as a draw day. Not more than fifty percent of said earned monthly salary of each such county officer or employee shall be paid to him or her on the draw day. If officers and employees are paid once a month, the draw day shall not be later than the last day of each month. The balance of the earned monthly salary of each such officer or employee shall be paid not later than the fifteenth day of the following month.
In counties with a population of less than five thousand salaries shall be paid monthly unless the county legislative authority by resolution adopts the foregoing draw day procedure.
RCW 36.17.040
Purpose-Captions not law-1991 c 363: See notes following RCW 2.32.180.