70 ILCS 2605/65

That The Sanitary District of Chicago be and it is hereby authorized and empowered to contract upon such terms as may be agreed upon with the corporate authorities of any city, incorporated town or village within the limits of The Sanitary District of Chicago to allow and permit The Sanitary District of Chicago to enter upon and use any sewer or drain or any system of sewerage or drainage or any part thereof or any sewage treatment works or part thereof of any such city, incorporated town or village, and to enlarge, reconstruct, repair, maintain and operate the same.