WASHINGTON (NEXSTAR) — Cities and counties across America are wondering what to do with the mountains of recycling material we leave at the curbside each week.

Much of the paper and plastic American households recycle used to be sent to China for processing, but at the end of 2017, China stopped accepting nearly all of those materials because they weren’t clean enough.

“We’d been sending shipments that were 30 – 40% contaminated. They set a limit of about 0.5%, which is just not possible to meet,” Cooper Martin explained.

Martin, the director of Sustainability and Solutions at the National League of Cities’ Center for City Solutions, says China was the single largest consumer of recyclable materials generated by the United States.

Now, local governments are scrambling to find new ways to dispose of those materials without going broke in the process.

“Some communities are putting some of their materials in the trash,” Martin added. “That’s really a short-term step until they figure out how and they can educate their residents.”

Joe Pickard, chief economist and director of commodities at the Institute of Scrap Recycling Industries, Inc., says China’s policy changes made some recycling programs more expensive and harder for some communities to afford.

“As China has purchased less and less of recycled commodities, recyclers have had to find different homes for that material,” he explained. “That makes it less economically viable to sell them, and so it raises the costs for recycling.”

Solving the problem will take time, but Americans can help right now by learning new recycling habits such as doing more to clean and sort their recyclables.

“Start to figure out how we can separate these materials domestically before we need to send them to overseas markets,” Martin added.

Martin says investment in domestic recycling programs will also help.

“Industry is stepping up,” he said. “They are making investments in mills this side of the ocean and in a couple of years, those are going to come online.”