1. The board of directors of any public water supply district may petition the circuit court of the county containing the major part of the acreage in the district for an amended decree of incorporation to allow that district to engage in the construction, maintenance and operation of common sewer treatment facilities which serve ten or more separate properties and are located wholly within the district and are not operated by another political subdivision or are not located within the certificated area of a sewer corporation as defined in chapter 386 or within a common sewer district as defined in chapter 204 and the operation and maintenance of all such existing sewer treatment facilities. The petition shall be filed by the board of directors and all proceedings shall be in the same manner as in an action for initial formation of a water district except that no vote of the residents of the district shall be required.

2. If the decree is amended the district shall, within ninety days after the order amending the decree, begin operation of the existing facilities which it has acquired by gift or otherwise and shall establish and collect user charges to be determined and established in the same manner as water rates.

3. All applicable provisions of this chapter shall apply to the construction, operation and maintenance of common sewer facilities in the same manner as they apply to like functions relating to water supply.