Don't Recycle Your Used Pizza Boxes!
The biggest problem for nearly all recycling centers is contamination, usually food and liquid. A single stained pizza box can often ruin a whole load of otherwise good recyclables. It has been estimated that contamination costs Denver recycling facilities thousands of dollars every year.
If you leave a half-consumed can of Coke in with that nasty food-sludged pizza box, and the can is smashed during recycling, the liquid soaks all of the paper and cardboard in that load – rendering ALL of it useless and destined for a landfill. Most recyclables are made of very absorbent material, so the slightest bit of old soda, food, beer or wet trash will end up as "residue" in the recycling facility, before it goes into the landfill. A quick check of your local recycling center website will give you an easy-to-follow list of best practices. Most recycling centers will not accept metal, wood, or rubber, so keep your home remodeling waste out of the bin.
Single-stream recycling programs will accept mixed materials that are sorted by employees, but most recycling centers do not do this. A materials recovery facility always does single-stream recycling, using machines and employees to sort through trash. The trucks deliver the trash to a large steel bin where a drum feeder divides the materials up on to conveyer belts. Any metal will be removed by magnets. Workers remove any trash that remains after the drum feeder and the load is baled. Glass is the only material that isn't baled.
In 2017, Waste Management recycled 174,420 tons of bottles, cans, paper and cardboard saving 1.3 million trees, 759 million gallons of water, and 373 million kWh of electricity. The Denver Arapahoe Disposal site is turning landfill gas into electricity that powers 2,500 homes annually. These are excellent results that can get better as long as we look out for contaminated trash and get to know our local recycling center.
In order to know what's acceptable for your local recycling center, go to earth911.org and enter your zip code or call your local facility and ask.