358C.15  Rentals and charges.
  1.  A board of trustees may by ordinance establish equitable rates, charges, or rentals for the utilities and services furnished by the district to be paid to the district by every person, firm, or corporation whose premises are served by a connection to the utilities and services directly or indirectly. The rates, charges, or rentals, as near as may be in the judgment of the board of trustees, shall be equitable and in proportion to the services rendered and the cost of the services, and taking into consideration in the case of the premises the quantity of sewage or water produced or used and the concentration, strength, and pollution qualities of the sewage. The board of trustees may change the rates, charges, or rentals as it may deem advisable, and by ordinance may provide for collection. The board may contract with any municipality within the district, whereby the municipality may collect or assist in collecting any of the rates, charges, or rentals, whether in conjunction with water rentals or otherwise, and the municipality may undertake the collection and render the service. The rates, charges, or rentals, if not paid when due, shall constitute a lien upon the real property served by a connection. The lien shall have equal precedence with ordinary taxes, may be certified to the county treasurer and collected in the same manner as taxes, and is not divested by a judicial sale.
  2.  Sewer rentals, charges, or rates may supplant or replace, in whole or in part, any monetary levy of taxes which may be, or have been, authorized by the board of trustees for any of the following purposes:
  a.  To meet interest and principal payments on bonds legally authorized for the financing of sanitary utilities in any manner.
  b.  To pay costs of the construction, maintenance, or repair of the facilities or utilities, including payments to be made under any contract between municipalities for either the joint use of water or sewage facilities, or for the use by one municipality of all or a part of the water or sewer system of another municipality.
95 Acts, ch 200, §15