65 ILCS 5/11-74.2-4
If as a result of their initial study and survey the corporate authorities determine that one or more commercial blight or conservation areas exist in the municipality, they may by resolution set forth the boundaries of each commercial blight or conservation area and the factors that exist in the blight or conservation areas that are detrimental to public health, safety, morals and welfare.
In the same resolution the corporate authorities may provide for a public hearing on commercial blight or conservation and may submit proposed redevelopment plans for the blight or conservation areas. At least 20 days before the hearing the municipal clerk shall give notice of the hearing by publication at least once in a newspaper of general circulation within the municipality.
65 ILCS 5/11-74.2-4