6. Denver Arapahoe Disposal Site, Aurora, Colorado. 2,561,809 tons.
Colorado’s largest landfill, Denver Araphoe Disposal Site accepts around 12,000 tons of waste per day. But some of that trash is going to good use. In September of 2008, DADS launched its waste-to-energy system to convert methane into electricity. In partnership with the City of Denver, the system generates enough power to fuel about 3,000 homes. (Photos are from adjacent landfill site Lowry, which ceased operations in 1990 and is now part of the waste-to-energy system)