Consistent with the water resource planning process of the department of ecology, the department of health shall:
(1) Develop procedures and guidelines relating to water use efficiency, as defined in *section 4(3), chapter 348, Laws of 1989, to be included in the development and approval of cost-efficient water system plans required under RCW
43.20.050;
(2) Develop criteria, with input from technical experts, with the objective of encouraging the cost-effective reuse of greywater and other water recycling practices, consistent with protection of public health and water quality;
(3) Provide advice and technical assistance upon request in the development of water use efficiency plans; and
(4) Provide advice and technical assistance on request for development of model conservation rate structures for public water systems. Subsections (1), (2), and (3) of this section are subject to the availability of funding.