Fans blow landfill’s methane away from Everett development

EVERETT — Just north of the blue and gray cookie-cutter homes and manicured sidewalks of the newly constructed Riverfront Development, remains of the old Everett landfill decay, releasing methane gas as they decompose.

Today, the only clue to passersby of what lies below are two fans at either end of the property. Surrounded by barbed wire-topped chain link fence, they emit a high-pitched hum as they suck the gas from the soil and blow it out through a steel pipe.

Plans for a six-phase development along the Snohomish River — with 1,250 multi-family units, a theater, small grocery, possible medical clinic, hotel and office building — will cover nearly the entire 70-acre former landfill. The property is just east of I-5 between the 41st Street roundabout and 36th Street, where Shelter Holdings is building the next phase.

“It was your run-of-the-mill landfill site that accepted all kinds of man-made waste,” said Randy Loveless, an associate engineer with the city of Everett.

The city operated the landfill from the early 1900s to 1974, when they decommissioned it by grading the material and laying down a 12-inch layer of soil.

The developer, Shelter Holdings, bought the land and started building atop the landfill in late 2019.

“It seems crazy,” Loveless said. “But it’s one of those deals where with careful design and planning you can do it in a way that’s not just safe but restores that area to a condition that’s better than when it was left.”

The landfill will continue to generate small amounts of methane gas for years to come. But the rate it’s produced at has slowed substantially, and will continue to diminish over time. The landfill currently generates about 15% of what it did at its peak in the mid-to-late 1970s. By 2030, that figure should drop to 10%.

There are four ways the left-behind waste can impact the environment and human inhabitants, Loveless said.

The first is direct contact with the refuse. The soil cap takes care of that.

There’s also potential for nutrients from the waste to seep into groundwater or wash off through rain into the river and other nearby bodies of water. The soil cap also helps address those.

Then there’s the gas generated by degradation of landfill materials. The methane gas released by decaying organic matter is captured by a network of piping installed under the soil cap. It’s essentially a large vacuum system that sucks the gasses out of the soil, Loveless said.

The gas is collected and sent to the two blowers, where it’s discharged into the atmosphere.

There are two blower locations — each on either end of the former landfill. They’re highly regulated by federal standards, Loveless said.

Much of the blower system has been there for nearly 20 years. But as the riverfront development grows, the city improves it and adds capacity.

Most folks would just walk past the nondescript metal stack inside its chain link pen without a second glance, Loveless said.

“You would hear fans running but you’d never suspect anything,” he said.

There’s no odor or vapor.

The city hires a consultant to keep a close watch on the blowers. In December, the city council approved a $150,000 contract, paid by the city of Everett and the state Department of Ecology, to keep the system in check over the next three years.

“It’s a way of sort of recycling a part of our community that has been discarded,” Loveless said. “And that’s really a neat thing to be a part of.”

This story has been modified to more precisely describe the location of the former Everett landfill.

Julia-Grace Sanders: 425-339-3439; jgsanders@heraldnet.com; Twitter: @sanders_julia.