Do food scraps ruin a whole batch of recycling in Kansas City? Your questions, answered

Editor’s note: This story is part of The Star’s series “Talking Trash.” All of the stories were inspired by questions and concerns we heard from Kansas Citians through listening sessions, an online callout and other conversations in our community. Stories will run throughout April, and you can find them all here. You can share thoughts in the form at the bottom of this story, or email kcq@kcstar.com. We’d love for you to join Star staff at a community cleanup event this month (more on that further down).

Kansas Citians are recycling less in recent years than they were before the pandemic.

When The Star asked readers to share questions and concerns about trash and litter in the metro, we heard a recurring theme from residents across more than 12 different KC area ZIP codes: Recycling is confusing, and many are skeptical about whether it works.

Some readers asked about specific items, while others had questions about the overall process.

The Star visited both of the recycling facilities that serve the metro area: WM’s facility in Shawnee, and GFL’s facility just outside Harrisonville, Missouri.

We wrote about how the process works overall, but we also asked recycling experts at both facilities some of your exact questions. Here’s what we found out.

Nathan Smith of southeastern Kansas City asked: Is it true that most things we put in the recycling bin are not actually recycled?

We learned: Around 20% of the items that local recycling centers receive are not actually recycled.

The sorting process that happens in these centers is designed to separate the recoverable material from items that should have ended up in the landfill. This includes plastic containers with the resin codes #3, #6 and #7 — learn more about those here.

Once non-recyclables have been removed, nearly 100% of the recyclable material makes it through the sorting process and gets sold back to manufacturers. Most of these buyers are domestic, but some cardboard from the metro gets sold to paper mills abroad.

Annemarie Kirby of the Northland asked: I’ve seen stories that wherever we were shipping plastic, they are no longer taking it, so the plastic is going into the landfill anyway. Is that true?

We learned: Some plastic that is not recyclable in the metro is ending up in the landfill — this includes filmy plastic bags, styrofoam and plastic containers with the resin codes #3, #6 and #7. But facility managers told The Star that recyclable plastics — those with codes #1, #2, #4 and #5 — now have domestic destinations that aren’t impacted by China.

Recycling is extremely regionalized, so in some places, a lack of foreign end markets for plastic may pose a problem. However, the two facilities in the KC metro sell all of their recycled plastic back to domestic manufacturers.

One example is Mohawk Flooring, which buys recycled water bottles to process into the plastic backing on carpets.

Annemarie also asked: Are all caps recyclable? Many are not marked with the recycle symbol.

We learned: Loose caps may not make it through the recycling process because they are too small to be sorted by some machinery. However, if you screw the caps onto bottles and cartons before recycling them, they can be recycled.

Jeremy Cooper, who manages the Harrisonville facility, added that squeezing some air out of plastic bottles before screwing the cap back on makes them easier for machinery to process.

What are Kansas City’s top 10 recycling mistakes? Read about them here.

Carolyn Fisher of midtown asked: If there is a large cellophane window on an envelope, will it be recycled?

We learned: Recycling facilities can handle paper envelopes that have plastic windows, both local recycling facility managers told The Star. This small amount of plastic won’t ruin a batch of recycled paper — but larger amounts, especially of filmy plastic like cellophane or grocery bags, will.

Carolyn also asked: If there is a trace of liquid detergent in the bottom of the container, will it still be recycled? Traces of cat food in a can?

Both facility managers agreed that small amounts of food and other contaminants won’t make or break a recyclable item. Buyers allow a small amount of contamination in finished bales — but a large amount of these substances can cause problems for both recycling machinery and the end product it produces.

The takeaway: A few smears of yogurt in the bottom of a tub are okay. Half a pizza still in the box, not so much.

Matthew Bunyard of Kansas City, Kansas, asked: I’ve heard unrecyclable materials can lead to whole loads being thrown out instead of being recycled.

We learned: This is mostly false. Recycling facilities use sophisticated machinery as well as human pickers to separate recyclable items from non-recyclable items.

However, packaging recyclables in plastic trash bags can lead to these particular bags being sent to the landfill, because filmy plastic can gum up sorting equipment. For this reason, it’s best to leave your recyclables loose so the facility can easily sort them.

Stephen Hawks of the Northland asked: What are the actual “mechanics” of plastic recycling, how does it work?

We learned: Filmy plastic is first removed from the recycling stream by human sorters at the Harrisonville facility and machines with rotating combs at the Shawnee facility.

Sorters may have time to rip open plastic garbage bags containing recyclables — but not always. Garbage bags that don’t get opened are typically diverted to the landfill.

Recycling centers then run conveyor belts filled with recycled items under a series of high-tech machines called optical sorters. These devices use cameras to identify different materials, including various types of plastic. They then use air jets to send material into a designated chute, where it is collected and compressed into a dense brick called a bale.

The Harrisonville facility also uses high-speed robots to “pick” plastics out of the stream and get them to the proper collection area — although facility manager Cooper told us that these robots still are not as efficient or precise as human sorters. Bales of these plastics are then sold to manufacturers around the country.

Joel Walsh of the Historic Northeast said: I would be curious if the city has any objection to publicly posting information about the tonnage of different commodities they collect to the city’s website, along with who the commodities are sold to.

We learned: Both of the recycling facilities that serve the Kansas City area are operated by private companies. The end destinations of recycled materials are constantly changing, so facility managers said it is difficult to share exactly where each truckload ends up.

Tronnie Blair, the manager of the Shawnee facility, said that 100% of his materials are sold to domestic buyers. Cooper said that most plastic and metal from the Harrisonville facility stays in the U.S., but some paper and cardboard is sold abroad to manufacturers in India and Malaysia.

Harry Reed of Shawnee asked: What numbers in that little arrowed triangle get recycled and which get trashed? What about milk cartons, whether paper or plastic? Styrofoam if it has the recycle number and symbol?

We learned: That little triangle doesn’t necessarily mean a material is recyclable: It just means that the item is made from plastic resin. The number inside represents the type of resin, which is what determines its recyclability.

Recycling facilities in the Kansas City area currently accept plastic containers bearing the codes #1, #2, #4 and #5. This includes many common plastics like water bottles, milk jugs, clean food containers, cleaning product bottles and other household plastic items.

Plastic and paper milk jugs are both recyclable. Styrofoam containers are never recyclable in Kansas City, even if they have a triangle symbol and a number on them. Check out our recycling guide for more information about what you can and can’t recycle in the metro.

Do you have more questions about recycling in Kansas City? Ask the Service Journalism team at kcq@kcstar.com.