Wash. Rev. Code § 36.36.030
Aquifer protection areas are authorized to impose fees on the withdrawal of subterranean water and on on-site sewage disposal. The fees shall be expressed as a dollar amount per household unit. Fees imposed for the withdrawal of water, or on-site sewage disposal, other than by households shall be expressed and imposed in equivalents of household units. If both types of fees are imposed, the rate imposed on on-site sewage disposal shall not exceed the rate imposed for the withdrawal of water.
No fees shall be imposed in excess of the amount authorized by the voters of the aquifer protection area. Fees shall only be used for the activity or activities authorized by the voters of the aquifer protection area. Ballot propositions may be submitted to the voters of an aquifer protection area to authorize a higher maximum level of such fees or to authorize additional activities for which the fees may be used. Such a ballot proposition shall be substantially in the form of that portion of the proposition to authorize the creation of an aquifer protection district that relates to fees or activities, as provided in RCW 36.36.020. Approval of the ballot proposition by simple majority vote shall authorize the higher maximum level of fees or additional activities for which the fees may be used.
A county may contract with existing public utilities to collect the fees, or collect the fees itself.
RCW 36.36.030