What Does Away Look Like? Where Kirkland’s Trash, Recycling and Compost Go

Staff pick contaminants off of conveyor lines  of mixed paper

Workers sort mixed paper at the Cascade Recycling Center

Every week we dutifully drag our three carts to the curb for pickup, and the materials we’ve carefully sorted are taken away…but where, exactly, do they go?

As Kirkland’s new Solid Waste Education and Outreach Specialist, it was important to go see for myself just where our trash, recycling, and compost winds up. This month, I toured the Cedar Hills Regional Landfill, Cascade Recycling Center, and Cedar Grove Composting Facility to see what “away” looks like. On the way, I picked up some tips for making sure our waste gets processed as best as it can.

Trash Gets Buried at Cedar Hills Regional Landfill

Kirkland’s trash is trucked to King County’s Cedar Hills Regional Landfill in Maple Valley. 800,000 tons of trash from across King County goes to the landfill each year.

Active landfill cell at Cedar Hills in front of Mount Rainier.

A working cell at the landfill.

Dozens of trucks a day dump their loads into open cells and bulldozers compress the material. When the cell is full, it’s covered in dirt and left to decompose (verrrrrrry slowly – think centuries). Perforated pipes suck methane gas produced during decomposition to an onsite plant to produce energy. Other pipes route contaminated rainwater to leachate ponds where huge turbines froth the water so toxins will break down.

Common Misconceptions about Landfills

  • “Someone picks recyclable stuff out of my trash” Nope! It heads straight from curb to transfer station, then to the landfill. We rely on you to separate out your food waste and recyclables before your trash gets picked up.
  • “The dump must be disgusting” – Open cells are covered with tarps every night to prevent trash from blowing away, and buried with dirt when the cell is full. We saw a herd of deer wandering around the landfill, and elk and eagles use the area as well. And what a view!
  • “Once it’s full we’ll just build a new one and never come back to Cedar Hills” – After the landfill closes (slated for 2026), King County will continue to monitor gas production and leachate runoff for decades. There probably won’t be another landfill built in King County, so our trash will get shipped further away at a higher cost to everyone.

Recycling Gets Sorted at Cascade Recycling Center

Every day, the Cascade Recycling Center receives 600 tons of recyclables, the vast majority from homes.

bales of mixed paper and plastics ready to be sold

Baled recyclables, ready to be sold and processed into new goods.

Cascade Recycling Center is a cacophonous maze of efficiency that separates materials so they can be sold and turned into new goods. Recyclables are sorted by a variety of machines plus an astonishing number of people who manually pick out what the machines missed. Spinning wheels float cardboard and newspapers above the stream. Suction conveyor belts separate paper from plastic bottles. Optical sorters identify bottles and cans mixed with paper. Magnets pull out steel, while an eddy current separates aluminum cans from plastic bottles.

Recyclables on steep conveyor belt at Cascade Recycling Center

Recyclables climb a conveyor belt early in the sorting process.

Conveyor belt feeding glass to crusher.

Glass gets crushed and eventually turned into wine bottles in Seattle.

Workers picking contaminants off conveyor line at Cascade Recycling Center.

Picking out trouble items like holiday string lights and wires that could foul up the equipment.

Workers pick plastic out of mixed paper stream

Workers pick contaminants like plastic bags out of mixed paper.

rectangular bale of mixed paper coming out of baling machine

Paper being baled for sale and recycling.

Pro Recycling Tips

  • Recycle plastics by shape, not by number.
  • How clean is clean enough? Dump out any remaining contents, and if there’s food residue, give it a quick rinse; no need to run recycling through the dishwasher.
  • Coffee cups like you get from Starbucks are usually recyclable, not compostable; they have a plastic lining that prevents composting, but that recycling facilities are able to separate.
  • Plastic bags jam the conveyor lines, so we no longer accept them in your curbside containers – but you can still recycle plastic bags at collection stations at the ParkPlace QFC and Totem Lake Fred Meyer, or more locations around King County at bagyourbags.com.

Compost Goes to Cedar Grove in Everett or Maple Valley

Cedar Grove turns our food and yard waste into nutrient-dense compost at facilities in Everett and Maple Valley. Decomposition requires the right ratio of carbon (“browns”) to nitrogen (“greens”). Cedar Grove separates their year into Jack-o-Lantern Season, Christmas Tree Season, and Lawn Clipping Season, adjusting their recipe of browns and greens to keep the process running smoothly when they receive huge quantities of seasonal compostables.

steaming compost at Cedar Grove

On the right, gore-covered piles of compost; on the left, steaming piles of ready-to-sell compost.

Food and yard waste is chopped up and mounded into Gore-covered piles (breathable like your Gore-tex jacket) for weeks. Inside, the piles reach 170 degrees F, hot enough to kill bacteria and break down pesticides. The compost is screened for trash (plastic bags, produce stickers, plant tags, etc) and piled up for a second round of composting and screening.

Sorting machine piling compost for sale and oversized pieces

Finished compost is piled on the right, while material that didn’t break down small enough is separated out on the left to go back through the process.

Help Make Good Compost

  • No plastic bags in your bin! If you want to bag your compost, use biodegradable bags like BioBags.
  • Pick the stickers off your banana peels and orange rinds, and untwist the wire from your carrots and kale. Produce stickers and ties are trash.
  • Use approved compostable plates, cups, and cutlery at get-togethers – Cedar Grove branded items or uncoated paper products like Chinet. Coffee cups like you get at Starbucks are recyclable, not compostable.
  • Take your yard waste cart to the curb for pickup every week, not just when it’s full. That prevents it from getting smelly.
  • Absolutely no pet waste.

Take Your Own Tour

All three facilities offer tours to the public, particularly community groups and businesses. I encourage you to go see what Kirkland’s “away” looks like yourself – and bring a friend!