(70 ILCS 2405/23.2) (from Ch. 42, par. 317e.2)
    Sec. 23.2. Any sanitary district may annex any territory contiguous to it even though the annexed territory is dedicated or used for street or highway purposes if no part of the annexed territory is within any other sanitary district. After passage of the ordinance of annexation a copy of the ordinance with an accurate map of the territory annexed certified as correct by the Clerk of the District shall be filed with the County Clerk of the County in which the annexed territory is situated.
(Source: Laws 1961, p. 552.)