Russell Coco pleaded guilty Tuesday to federal charges resulting from the illegal removal of asbestos during a renovation of the Equitable Building, 604 Locust St. Coco worked on the project with real estate developer Bob Knapp, who also has been charged and is awaiting trial Feb. 28 in U.S. District Court in Des Moines. In a plea agreement, Coco said he conspired to violate the Clean Air Act and violated work standard practices related to asbestos removal. He faces a year in prison and a $250,000 fine. Sentencing is set for May 20. Coco was the construction manager on the project. Luxury condominiums, offices and retail shops were planned for the building, which is in receivership.