Any portion or portions of a county, whether contiguous or noncontiguous, and whether the portion or portions include incorporated or unincorporated territory, may be formed into a garbage disposal district in the manner and under the proceedings set forth in this chapter, except that less than the whole of any city shall not be included in the district without unanimous consent of the governing body of the city and no parcel of noncontiguous territory which is less than a full subdivision or which contains less than 10 privately owned acres may be included in any district.