A public utility district as authorized by a county board of health, may perform operation and maintenance, including inspections, of on-site sewage disposal facilities, alternate sewage disposal facilities, approved septic tanks or approved septic tank systems, other facilities and systems for the collection, interception, treatment, and disposal of wastewater, and for the control and protection, preservation, and rehabilitation of surface and underground waters. Those costs associated with the maintenance of private on-site sewage systems may be charged by the public utility district to the system owner.
RCW 54.16.310