Waste Loop Visits the SMaRT Center

Emma Allison
June 2, 2022

Waste Loop employees recently visited the Spokane Material Recovery Technology Center. Also known as the SMaRT Center, this is Waste Management’s regional recycling sorting facility, and it is where all of our single-stream recyclables get sent. The facility is a large warehouse located right next door to the Spokane Waste to Energy (WTE) Plant, where most of the city of Spokane’s solid waste is burned to generate electricity. Opened in 2012, the SMaRT Center sorts recyclables from homes and businesses in Washington, Idaho, and British Columbia. 

After watching a quick introductory video, the tour really began when we walked into the main room of the warehouse where the sorting was happening. We walked up some steps, over a conveyor belt, and across a platform. We were able to look through a window into the area where truckloads of recyclables were dumped and mixed, known as the tipping station. The materials then went up a conveyor belt past where we were standing to be pre-sorted. A few workers were standing by the conveyor belt pulling out any obvious contaminants that could damage the sorting machines. They especially try to remove extension cords that could get tangled in machinery, large chunks of metal or plastic, and plastic bags or bagged recyclables. Once removed, these items go to different bays, and unwanted materials are eventually sent next door to WTE. 

After the pre-sorting process, the conveyor belt went through two different “screens” to sort out cardboard (Old Corrugated Cardboard, OCC) and paper (Old Newspaper, ONP). These screens are large spinning disks that allow cardboard and paper to float on top, and heavier, bulkier materials to drop down. After being screened, the cardboard and paper continue on a conveyor belt and are checked by workers to remove any sneaky contaminants. After this inspection, the cardboard and paper are sent to bunkers where they await bailing.

All of the materials that fall through the paper screens are then sorted further. Plastics are sorted using a variety of techniques. Bottles are sorted out by type: PET, HDPE(N), and HDPE(C). PET, polyethylene terephthalate, is clear plastic such as drink bottles. HDPE, high-density polyethylene, are sorted based on whether it is colored (HDPE(C)) opaque plastic, or natural (HDPE(N)) such as translucent milk jugs. The conveyor belt is sent through an optical sorter to sort PET from HDPE. An optical sorter is a machine that uses a camera to identify PET materials on the conveyor belt, then correctly time a blast of compressed air to shoot the material off of the belt and into another area. The remaining materials continue on the belt to be sorted by workers who throw the plastics into the correct bunkers where PET, HDPE(n), and HDPE(c) materials await bailing.

Metals are sorted out using different techniques as well. Ferrous metals, such as tin and steel, are sorted out using magnets. These materials are then collected in a bunker for bailing. Eddy current technology is used to separate aluminum cans from other materials. A strong magnetic field is created and moves across the belt, shooting aluminum materials off of the belt while non-aluminum materials remain. The aluminum cans are then collected into a separate bunker for bailing. 

Once the materials are sorted, they are bailed and prepared for shipment to different locations where they will be used in the production of new goods. One of the biggest takeaways from the tour is that recycling depends entirely on the market for materials. WM is only able to accept what they are able to sell. The market changes so frequently that it is hard to predict where materials will actually end up. In general, paper and cardboard materials are recycled locally in Washington. Tin is currently sent to Oregon, and Aluminum is sent to the East Coast. Plastics are the most elusive and don’t seem to have a consistent market. When countries overseas such as China stopped accepting recyclables from the United States in 2018, the few local markets that existed for plastic recycling were flooded with an excess supply. This allowed them to be pickier as to what materials they would accept, resulting in changes to curbside collection. According to WM, bottles are the only plastics that this region can recycle because of this change in markets and the general lack of local recycling infrastructure.

When asked about the biggest issues this facility faces, the answer was definitive: plastic bags and “wish-cycling”. WM has launched education focused on reducing the amount of plastic film ending up at this facility, and especially about not bagging recyclables. Recyclables should always be placed loosely in the cans, never in bags. Any bagged materials are removed from the line in pre-sorting without being opened, so if you bag your recyclables, they are not being recycled. As for wish-cycling, the solution is simple: follow local recycling guidelines, and when in doubt, throw it out. Putting unacceptable materials into recycling bins is considered contamination, even if it is a material that is recyclable in a different municipality. To review, recyclable materials in Leavenworth are plastic bottles, cardboard, mixed paper, and metal cans. Recyclables must be clean, empty, and unbagged. 

Lastly, we asked whether recyclables were ever sent to the landfill if they were too contaminated. According to WM, this does not happen and is not financially sensical. WM understands that there is confusion about what actually happens with recyclables, especially because the same trucks are used to transport landfill waste and recyclables. However, all materials meant to be recycled are sent to the SMaRT Center. Waste Management trucks have cameras to capture what is being dumped into the truck from each bin. If it is a heavily contaminated bin, WM drivers can take note of the bin and charge customers extra for not recycling correctly. These materials are still taken to the SMaRT Center for sorting, and contaminants are burned in the WTE facility. 

This visit was incredibly interesting, and if you ever have the opportunity to tour the SMaRT Center, you should take it. Recycling can be confusing because rules vary so much regionally and temporally, but if you take the time to learn local guidelines, you can help maintain the health and efficiency of recycling waste streams. My biggest takeaway from this visit was that we need more local recycling infrastructure. In an industry so reliant on a highly varied market, having more outlets for materials would increase the stability of this system and allow for more materials to be recycled. There is also room for improvement in education on how waste is managed. Having a deeper understanding of where your waste goes is incredibly valuable and will help broaden your understanding of the need for more sustainable practices.

Unfortunately we couldn't take photos inside the SMaRT Center - instead check out Waste Management's video here.