As of July 9, 1951, 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:
     Those portions of Sections twenty (20) and twenty-nine (29), and the East Half (E1/2) of Section nineteen (19), and the East forty (40) acres of the North West Quarter (NW1/4) of Section nineteen (19) lying North of the center line of the Little Calumet River, all in Township thirty-six (36) North, Range fifteen (15), East of the Third Principal Meridian, in Cook County, Illinois.