(1) The county board, in addition to other sources of revenue available to the county, may by resolution set up a rental or use charge, to be collected from users of any sewerage disposal system and plant or plants, and provide methods for collection of the rental or use charge. The charges shall be charged to the real property served by the sewerage disposal system, shall be a lien upon the real property served, and may be collected either from the owner or the person, firm, or corporation requesting the service.

(2) All money raised from the charges referred to in subsection (1) of this section shall be used for maintenance or operation of the existing sewerage disposal system and plant or plants, for payment of principal and interest on bonds issued, or to create a reserve fund for the purpose of future maintenance or construction of a new sewerage disposal system and plant or plants for the county. Any funds raised from such charge shall be placed in a separate fund and shall not be used for any other purpose or diverted to any other fund except as provided in section 23-3625.