620 ILCS 25/22

(620 ILCS 25/22) (from Ch. 15 1/2, par. 48.22) Sec. 22. Non-conforming uses. No airport zoning regulations adopted under this Act shall require the removal, lowering, or other change or alteration of any structure or tree not conforming to the regulations when adopted or amended, or otherwise interfere with the continuance of any non-conforming use, except as provided in Sections 23 and 25. (Source: Laws 1945, p. 317.)