Aspen Waste Systems, a Minneapolis-based company, has opened an office in Commerce City, making it the newest player in metro Denver’s competitive waste disposal and recycling market. A top 20 waste hauler nationally, with 350 employees and a fleet of 240 trucks, the company doesn’t own any landfills. Instead, it has focused on providing “premium” waste stream management and hauling services to clients using newer trucks and dumpsters. “We have watched Denver for a while now and we have been evaluating it,” said Alexa Kircher Fang, the company’s president and daughter of CEO Robert Kircher, who founded the company in 1990.