Recycling is one of the best and easiest steps an individual can take to help improve the environment, but many people do it incorrectly, creating more problems than it solves.

When sorting material, many people will mix material that cannot be recycled with the reusable goods. While in most cases the contamination is inadvertent, it creates real challenges for waste management plants and local governments.

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When contamination is spotted, workers have to take extra time to remove the unusable waste. This can require shutting down automated sorting machines to clean out tangles and prevent certain material from making it into processing.

“Ten years ago, when people were more careful about sorting, we’d get 98 percent usable glass,” Curt Bucey, an executive vice president at glass recycling firm Strategic Materials, told Waste360. “Today, because people just throw whatever they want into their single bin, we’re at about 50 percent. There’s no care at the curb, and that goes to our facilities and it takes time to remove the contamination — or we just tell the haulers we can’t pay for as much as we used to, which makes their costs go up.”

That lack of sorting at home leads to more sorting needed at the waste facility, which creates less output of recyclable material. When the returns on that material become less, cities and municipalities invest in it less, exacerbating the issue.

The waste that does get recycled is worth less than it used to be, too. A study by the North Carolina Department of Environmental Quality found the average market value of a ton of mixed recyclable material in the state has dropped by more than $100 in recent years, from $180 in 2011 to less than $80 in 2015. That decline makes the prospect of making a profit from recycled material more difficult.

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There are a number or reasons for the drop in value, including new limits on imported waste introduced by major consumers like China. There has also been an overall drop in demand as growth rates in developing nations has leveled off, David Biderman, executive director and CEO of the Solid Waste Association of North America, said in an interview with USA Today.

Low oil prices have made it less expensive for manufacturers to produce new plastic bottles, in turn lessening the demand for recycled plastic. Packaging producers have also improved on methods to make materials like bottles and cans thinner, requiring less raw material. And the demise of the newspaper industry has lessened the need for recycled paper fiber.

To combat the issue, the best thing recyclers can do is try to improve their sorting techniques at home to lighten the load for waste management plants. Check with your local municipality for specific recycling rules to make sure you aren’t accidentally including material that cannot be used.