On or around December 15, 2023, Vertellus idled the Facility and ceased burning hazardous waste in its boilers. If Vertellus resumes operation of the Facility, the ACO requires Vertellus to comply with the HON?s LDAR provisions and the HWC MACT?s carbon monoxide emission standard. The ACO addresses the violations set forth in the FOV issued to Vertellus on April 7, 2021.