(1) Every city and town may construct, condemn and purchase, acquire, add to, maintain, conduct, and operate systems of sewerage and systems and plants for refuse collection and disposal together with additions, extensions, and betterments thereto, within and without its limits. Every city and town has full jurisdiction and authority to manage, regulate, and control them and, except as provided in subsection (3) of this section, to fix, alter, regulate, and control the rates and charges for their use.
(2) Subject to subsection (3) of this section, the rates charged under this section must be uniform for the same class of customers or service and facilities furnished. In classifying customers served or service and facilities furnished by such system of sewerage, the city or town legislative body may in its discretion consider any or all of the following factors:
(a) The difference in cost of service and facilities to the various customers;
(b) The location of the various customers within and without the city or town;
(c) The difference in cost of maintenance, operation, repair, and replacement of the various parts of the system;
(d) The different character of the service and facilities furnished various customers;
(e) The quantity and quality of the sewage delivered and the time of its delivery;
(f) The achievement of water conservation goals and the discouragement of wasteful water use practices;
(g) Capital contributions made to the system, including but not limited to, assessments;
(h) The public benefit nonprofit corporation status, as defined in RCW
24.03A.245, of the land user; and
(i) Any other matters which present a reasonable difference as a ground for distinction.
(3) The rate a city or town may charge under this section for storm or surface water sewer systems or the portion of the rate allocable to the storm or surface water sewer system of combined sanitary sewage and storm or surface water sewer systems shall be reduced by a minimum of ten percent for any new or remodeled commercial building that utilizes a permissive rainwater harvesting system. Rainwater harvesting systems shall be properly sized to utilize the available roof surface of the building. The jurisdiction shall consider rate reductions in excess of ten percent dependent upon the amount of rainwater harvested.
(4) Rates or charges for on-site inspection and maintenance services may not be imposed under this chapter on the development, construction, or reconstruction of property.
(5) A city or town may provide assistance to aid low-income persons in connection with services provided under this chapter.
(6) Under this chapter, after July 1, 1998, any requirements for pumping the septic tank of an on-site sewage system should be based, among other things, on actual measurement of accumulation of sludge and scum by a trained inspector, trained owner's agent, or trained owner. Training must occur in a program approved by the state board of health or by a local health officer.
(7) Before adopting on-site inspection and maintenance utility services, or incorporating residences into an on-site inspection and maintenance or sewer utility under this chapter, notification must be provided, prior to the applicable public hearing, to all residences within the proposed service area that have on-site systems permitted by the local health officer. The notice must clearly state that the residence is within the proposed service area and must provide information on estimated rates or charges that may be imposed for the service.
(8) A city or town shall not provide on-site sewage system inspection, pumping services, or other maintenance or repair services under this section using city or town employees unless the on-site system is connected by a publicly owned collection system to the city or town's sewerage system, and the on-site system represents the first step in the sewage disposal process. Nothing in this section shall affect the authority of state or local health officers to carry out their responsibilities under any other applicable law.