The grants may be made to districts, authorities, nonprofit corporations or communities to assist in financing of, but not limited to, engineering and legal service costs, specific projects for construction, be it original or enlargement of supply, treatment, purification, storage and distribution facilities for water systems and collection, treatment, forced mains, lift stations and disposal facilities for sewer systems or any other item necessary for the physical operation of the water or sewer systems, where grant funds are necessary to reduce the project cost per user to a reasonable level. The grants may be made to supplement funds from loan proceeds or other private or public sources when such grants are not available through any other state or federal agency. Grants authorized under the provisions of this chapter may be applied to National Demonstration Water Projects upon the approval of the advisory committee.