Trash, like most of the nitty-gritty functions of a modern society, is often out of sight, out of mind. Most people don’t think about the intricate network of pipes delivering and removing liquids from their home until it breaks, or their trash disappearing each week from the curb unless a pickup is missed.

But by the end of the year, King County officials will need to figure out a long-term solution for dealing with the mountains of waste generated by more than 1 million people. Driving through the Cedar Hills Regional Landfill — the only landfill in the county — on a recent morning, King County Solid Waste Division assistant operations manager Scott Barden pointed to low-lying hills sitting in front of much larger ones. These smaller hills are areas of the landfill stretching back to the 1960s, but the county’s last landfill is in its last years.

“There probably will never be another landfill in King County,” he said, piloting his pickup truck toward a road winding up the side of a mountain jutting hundreds of feet in the air. The mountain is made almost entirely of trash.

Barden, assistant operations manager for the King County Solid Waste Division, sits in his truck atop the landfill on Jan. 18. Aaron Kunkler/staff photo

The view from the mountaintop is a sweeping panorama of the surrounding ridges, from the nearby Poo Poo Point where hang-gliders launch into open air and circle near Issaquah, to the jagged silhouettes of the Cascades to the east. Around 125 semi-trucks make the pilgrimage most days to this peak, where they dump containers carrying up to 18 tons of trash on its summit before tractors zip in to crush, compress, and rearrange the county’s garbage. Each night tarps are placed over the trash, and each layer is regularly filled over with dirt, sand, and permanent tarps as the landfill is built up. Deer, elk, and dozens if not hundreds of bald eagles frequent the landfill and can be seen most days swooping into piles of trash.

But this section of the landfill is almost full, nearly at its height limit of 788 feet above sea level. Around 300 feet below, a work crew was surveying the bottom of the landfill’s newest section, and likely its last. A massive pit 120 feet deep will be filled with the county’s trash through 2028, when its peak will match the one Barden’s truck sat on. By then, King County will need another way to deal with the roughly 3,000 tons of refuse that residents generate every weekday.

None of this is new knowledge. Seattle Weekly ran an article in 2017 exploring the ways King County was looking to deal with waste. However, what is different now is that the county has until the end of 2019 to select how it will proceed. King County produced a comprehensive solid-waste-management plan last year that lays out two long-term options for waste management after Cedar Hills closes. While county executive Dow Constantine directed the landfill to build its final section and buy the county nearly a decade to implement its new plan, the deadline is on its way, said King County Solid Waste director Pat McLaughlin. “It makes this decision-making process very time-critical because we have a relatively short period of time remaining before that next disposal solution is in place,” he said.

Scott Barden stands next to the pit which will house the newest, and possibly final, section of the Cedar Hills Regional Landfill near Maple Valley. The pi is 120 feet deep, and around another 180 feet will be built on top of it over the next decade. Aaron Kunkler/staff photo

The first option would resemble Seattle’s approach. Seattle is the only major city in the county that handles its own waste disposal. If this plan is picked, the county would contract with the railroad to ship its waste away. Seattle sends its garbage to a landfill in Arlington, Ore., and it’s unclear where the county could ship its refuse.

The second option — one supported and championed by King County Councilmember Kathy Lambert — would build a waste-to-energy plant where garbage from the county would be incinerated in a vacuum to create electricity. Lambert said the county will seek a study, expected to be completed by this fall. The county would own the facility but not run it; it would act as a county utility. Lambert has been studying ways to deal with trash for the past dozen years and has toured waste-to-power facilities in the U.S. and Europe.

The science behind whether waste-to-power plants are cleaner than landfills is contentious, depends on who is asked, as documented in the 2017 Seattle Weekly story. Some environmental groups say it’s hard to filter out toxins from the incinerators, and that ash often ends up at landfills in a finer form that makes it easier to contaminate the environment. Others argue that landfills are essentially “black boxes” that are difficult if not impossible to fully monitor for pollutants, which could be making their way into soil and ground water. King County monitors seven permanently closed landfills.

The Cedar Hills Regional Landfill is the only active landfill in King County. It will operate until at least 2028. It has been in operation since the 1960s. Photo by Aaron Kunkler

Cedar Hills itself is fairly high-tech, with more than 400 stations set up onsite to monitor the release of methane. Much of this gas is captured by a complex network of pipes that suck it out of the landfill to be refined by a Bio Energy Washington facility on the grounds. This is then sold to power companies, and produces enough energy to fuel around 19,000 homes each year. McLaughlin said the life of the landfill could be extended if administrative buildings are moved elsewhere to make room for another section. If recycling rates increase, the section currently being built could possibly last until 2040. Around 70 percent of the waste that is sent to the landfill could be recycled.

Waste-to-energy plants have historically been a hard sell in the U.S. By contrast, the European Union promotes the use of such facilities. The most recent plant in the U.S. was opened in 2015 in Palm Beach County, Fla. — and cost $672 million and took a decade to create. There are 87 waste-to-energy facilities across the country, including one in Spokane. This high price could prove a difficult sell in King County, along with contention surrounding the environmental impact of a plant.

“We think it’s feasible in the long term, but it does have a different level of financial and environmental impact, and I would say a less favorable financial and environmental impact,” McLaughlin said.

Scott Barden stands at the bottom of the massive pit of the landfill’s newly-built eighth section. Work on the new section has been underway for around two years. Photo by Aaron Kunkler

Lambert said modern power facilities capture most pollutants, and ash can be reused as a building material, turning trash into usable materials. On top of that, the comprehensive plan update said railroads have classified moving waste as low on its list of priorities. “Which makes this very vulnerable in my mind,” Lambert said.

More information will become available over the year as more feasibility studies are completed. No matter which choice the county makes, it will need to make its decision by the end of the year.