Any sanitary district heretofore or hereafter created in any county under the provisions of the preceding sections of this article may be abolished by ordinance adopted by the governing body of such county, upon the petition of no less than 50 qualified voters residing within the boundaries of the district desired to be abolished or, if the district contains less than 100 qualified voters, upon petition of 50 percent of the qualified voters residing within the boundaries of such district. Upon filing of the petition, the governing body of the county shall fix a day for a hearing on the question of abolishing the sanitary district, which hearing shall embrace a consideration of whether the property in the sanitary district will or will not be benefited by the abolition thereof, and the governing body of the county shall be fully informed as to the obligations and functions of the sanitary district. Notice of such hearing shall be given by publication three times in some newspaper of general circulation within the county to be designated by the governing body of the county, with the first publication appearing no more than 35 days before and the third publication appearing no less than seven days before the hearing. No such district shall be abolished until the notice has been given and the hearing had. Any interested parties may appear and be heard on any matters pertaining to the subject of the hearing. Upon the hearing, such ordinance shall be adopted as to the governing body of the county may seem equitable and proper, concerning the abolition of the district and as to the funds on hand to the credit of the district, provided, however, that no such ordinance shall be adopted abolishing the sanitary district unless any bonds of the sanitary district that have theretofore been issued have been redeemed and the purposes for which the sanitary district was created have been completed, or unless all obligations and functions of the sanitary district have been taken over by the county as a whole, or unless the purposes for which the sanitary district was created are impractical or impossible of accomplishment and no obligations have been incurred by said sanitary district.