(1) A metropolitan municipal corporation that is engaged in the transmission, treatment, and disposal of sewage may impose a capacity charge on users of the metropolitan municipal corporation's sewage facilities when the user connects, reconnects, or establishes a new service to sewer facilities of a city, county, or special district that discharges into the metropolitan facilities. The capacity charge shall be based upon the cost of the sewage facilities' excess capacity that is necessary to provide sewerage treatment for new users to the system.
(2) The capacity charge is a monthly charge reviewed and approved annually by the metropolitan council. A metropolitan municipal corporation may charge property owners seeking to connect to the sewage facilities of the metropolitan municipal corporation as a condition to granting the right to so connect, in addition to the cost of such connection, such reasonable capacity charge as the legislative body of the metropolitan municipal corporation shall determine proper in order that such property owners shall bear their equitable share of the cost of such system. The equitable share may include interest charges applied from the date of construction of the sewage facilities until the connection, or for a period not to exceed ten years, at a rate commensurate with the rate of interest applicable to the metropolitan municipal corporation at the time of construction or major rehabilitation of the sewage facilities, or at the time of installation of the sewer lines to which the property owner is seeking to connect but not to exceed ten percent per year: PROVIDED, That the aggregate amount of interest shall not exceed the equitable share of the cost of the sewage facilities allocated to such property owners. Capacity charges collected shall be considered revenue of the sewage facilities.
(3) The council of the metropolitan municipal corporation shall enforce the collection of the capacity charge in the same manner provided for the collection, enforcement, and payment of rates and charges for water-sewer districts provided in RCW
57.08.081. At least thirty days before commencement of an action to foreclose a lien for a capacity charge, the metropolitan municipal corporation shall send written notice of delinquency in payment of the capacity charge to any first mortgage or deed of trust holder of record at the address of record.