Wash. Rev. Code § 81.77.080
Every solid waste collection company shall, on or before the date specified by the commission for filing annual reports under RCW 81.04.080, file with the commission a statement on oath showing its gross operating revenue from intrastate operations for the preceding calendar year, or portion thereof, and pay to the commission a fee equal to one percent of the amount of gross operating revenue: PROVIDED, That the commission may, by rule, set minimum fees that do not exceed the cost of collecting the fees. The commission may by rule waive any or all of the minimum fee established pursuant to this section.
It is the intent of the legislature that the fees collected under the provisions of this chapter shall reasonably approximate the cost of supervising and regulating motor carriers subject thereto, and to that end the utilities and transportation commission is authorized to decrease the schedule of fees provided in this section by general order entered before March 1st of any year in which it determines that the moneys then in the solid waste collection companies account of the public service revolving fund and the fees currently to be paid will exceed the reasonable cost of supervising and regulating such carriers.
All fees collected under this section or under any other provision of this chapter shall be paid to the commission and shall be by it transmitted to the state treasurer within thirty days to be deposited to the credit of the public service revolving fund.
RCW 81.77.080