Stack testing of the emissions control systems at both Sterigenics facilities were conducted on Thursday (9/20/18) and Friday (9/21/18). The testing was performing by a third-party emissions testing consultant in conjunction with the IEPA. A representative from the Village of Willowbrook and a representative from the Tri-State Fire Protection District witnessed the testing. Mayor Trilla sent a letter to the IEPA requesting that the final results of the testing be sent to the Village by Wednesday, September 26, 2018.