When you toss your newspaper, or plastic bottle or aluminum can in a mixed recycling bin, someone, somewhere, has to sort the material out so it can be turned into something new.

The sorting is an expensive, labor-intensive process requiring fast-working humans and machines. Previously, much of that work happened in China.

But now, more sorting is happening closer to home, after China announced in 2018 it would ban the import of certain plastics and set extremely tough limits on contamination — materials brought into the country for recycling must be more than 99% pure.

Now, Prince George’s County, Md. has a fancy new piece of equipment — an optical sorter — to better separate different plastics, creating a more valuable product that can be marketed more easily.

“We are able to separate out cleaner, better bundles of more high value materials to ensure that more things get actually recycled,” says Andrea Crooms, director of the Prince George’s County environment department.

Previously, workers and machines at the county’s materials recovery facility in Capitol Heights would separate plastic from paper, metal and glass, and bundle the plastic all together in huge cubes, regardless of the plastic’s color or material. The new optical sorter can separate plastics by resin type — so your polyethylene terephthalate (that’s PET, clear plastic bottles and clamshells) won’t get mixed up with your high-density polyethylene (or HDPE, opaque milk jugs and other bottles). The machine can also separate by color, so plastics that have been dyed can be kept apart from the more valuable non-dyed plastics.

The new machinery will also allow the county to process more material. Last year, the recycling facility processed 3,500 tons of plastic; the new equipment will make it possible to process an additional 1,000 tons, according to county officials.

The sorting machine and other upgrades cost $6.3 million. Crooms says the machine will pay for itself in about five years.

The county won’t make any changes to the materials it accepts curbside. “It just allows us to take what we already accept and get more value for the residents, which reduces our overall waste costs,” says Coombs.

While there are a handful of other optical sorting machines in the region, this is the first one at a publicly-owned sorting facility in Maryland. Prince George’s recycling rate is higher than average among Maryland counties.

Crooms says China’s decision to cut down on its imports of recyclables may end up having a positive impact on recycling in the U.S.

“In the long run, it’s actually an opportunity for technological improvement and development, and a real commitment to identifying more ways to recycle these items,” Crooms says.

This story was updated to add more information from county officials about the sorting machine’s capacity.