70 ILCS 2605/96
As of July 1, 1919, the corporate limits of the Sanitary District of Chicago are hereby extended so as to embrace and include within the same, the territory and tracts of land situated in the county of Cook and State of Illinois, hereinafter described as follows:
Sections three (3), four (4), five (5), and six (6), in Township thirty-eight (38), North, Range twelve (12), East of the Third Principal Meridian; sections thirty-two (32), thirty-three (33) and thirty-four (34) in Township thirty-nine (39) North, Range twelve (12), East of the Third Principal Meridian, in the county of Cook and State of Illinois; and in addition thereto, any portion or portions of the incorporated villages of Brookfield, LaGrange, Western Springs and LaGrange Park which may not be included in the above description.
70 ILCS 2605/96