Any district is hereby authorized, within limits established by the Constitution of the state of Washington, to assist the owners of structures in financing the acquisition and installation of fixtures, systems, and equipment, for compensation or otherwise, for the conservation or more efficient use of water in the structures under a water conservation plan adopted by the district if the cost per unit of water saved or conserved by the use of the fixtures, systems, and equipment is less than the cost per unit of water supplied by the next least costly new water source available to the district to meet future demand. Except where otherwise authorized, assistance shall be limited to:
(1) Providing an inspection of the structure, either directly or through one or more inspectors under contract, to determine and inform the owner of the estimated cost of purchasing and installing conservation fixtures, systems, and equipment for which financial assistance will be approved and the estimated life-cycle savings to the water system and the consumer that are likely to result from the installation of the fixtures, systems, or equipment;
(2) Providing a list of businesses that sell and install the fixtures, systems, and equipment within or in close proximity to the service area of the city or town, each of which businesses shall have requested to be included and shall have the ability to provide the products in a workmanlike manner and to utilize the fixtures, systems, and equipment in accordance with the prevailing national standards;
(3) Arranging to have approved conservation fixtures, systems, and equipment installed by a private contractor whose bid is acceptable to the owner of the structure and verifying the installation; and
(4) Arranging or providing financing for the purchase and installation of approved conservation fixtures, systems, and equipment. The fixtures, systems, and equipment shall be purchased or installed by a private business, the owner, or the utility.
Pay back shall be in the form of incremental additions to the utility bill, billed either together with the use charge or separately. Loans shall not exceed two hundred forty months in length.