Justice Department spokesman Jeffrey Dorschner said the verdicts were delivered on Friday after an 11-day trial.
Executive Recycling Inc. is based in Englewood, Colo., but has affiliated locations in Utah and Nebraska.
The company, Brandon Richter and Tor Olson were convicted of wire and mail fraud; environmental crimes, smuggling and obstruction of justice.
Prosecutors say Richter was owner and former chief executive officer for the company while Olson was vice president of operations.
Former company officials could not be located for comment.
(Copyright 2012 by The Associated Press. All Rights Reserved.)