Authorizes the department of health, interested counties, and the department of ecology to: (1) Capitalize and administer a sustainable unified low-interest loan program to assist homeowners with the repair and replacement of on-site sewage systems and ensure the full implementation of a county's on-site program management plan; and

(2) Use any appropriate funding source for the implementation of the program and mutually develop the administration of the program in the manner that is deemed the most efficient, which may include administrating the program through the department of ecology's water quality financial assistance program.