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Mad scientist in the woods? Or, just another day at Vashon Treatment Plant

By July 6, 2023No Comments
A woman wearing a hard hat with King County logo, safety glasses, a reflective safety shirt, long pants and boots stands on an elevated walkway while holding a handrail.

Elizabeth (Lizzy) Corliss has run the Vashon Treatment Plant for the last four years.

Blink and you’d probably miss the driveway into Vashon Treatment Plant. Everything about this plant is pint-sized, a much scaled-down version of the massive clean water facilities servicing the mainland.  

Despite the solitude, a lot happens in this quiet, serene spot in the woods where all the wastewater going down the drains of more than 1,000 people on the island ends up.  

Elizabeth Corliss has been at the helm of Vashon Treatment Plant for four years now. Everyone calls her Lizzy. She grew up on Vashon and never knew the treatment plant was there until she joined King County’s Wastewater Treatment Division (WTD). “I tell people what I do, and they’re like, ‘What, we have that?’ 

Out of sight, out of mind is how most people think (or rather don’t think) about where all their wastewater goes. But at the Vashon Treatment Plant, Lizzy thinks about it, and manages up to 200,000 gallons of it, every day.  

Her record so far is impeccable. For the sixth consecutive year, Vashon has won an “Outstanding Performance” award by the Washington state Department of Ecology for consistently meeting permit requirements on cleaning pollution from the wastewater. The treatment plant also earned a Platinum Peak Performance Award from the National Association of Clean Water Agencies (NACWA) for the 12th year running. Puget Sound is all the cleaner as a result.  

Mad scientist 

A two-room building above the clarifier tanks is where Lizzy keeps tabs. There, she works out of a glorified kitchen where she stirs, mixes, bakes, and refrigerates samples of wastewater at various stages of the treatment process. Unlike operators at the larger treatment plants, at Vashon you have to be a jack of all trades.  “I not only work with the equipment outside, but I’m very closely tied to the process. I watch it, I analyze it, and I participate in the changes,” she says. “I’m about 40% operations and 60% mad scientist.”  

One test of dissolved oxygen tells her the bacteria activity, a sign of the concentration of organic matter in the wastewater. In another test she’s trying to grow fecal coliform on petri dishes, counting the blue dots to see the effectiveness of the ultraviolet disinfection system. Some of the “bugs” are good, some are bad. Some are really bad – like nocardia. “It’s one of the most interesting, the biggest side effect is usually the foaming.” You definitely don’t want foaming in the treatment process — what a mess! 

These tests help Lizzy monitor what’s coming into the system and how the treatment process is performing in cleaning the water before it’s sent to Puget Sound.  

A female worker wearing a King County reflective safety shirt prepares samples to test in a laboratory at Vashon Island Treatment Plant.

Samples taken from wastewater are cultured and analyzed in an on-site laboratory.

Female wearing King County safety shirt looks at information posted in a laboratory.

Vashon Island Treatment Plant houses a laboratory to test wastewater samples.

Butter and Skittles 

Lizzy gets a close-up view of what’s going on in her lab, but out in the plant she sees the problems occur at macro scale. The wastewater treatment process is kind of like your digestive system. Maintaining that delicate gut balance is essential and just one large wastewater user can throw the system off-kilter. If a restaurant dumps grease down their connection, our equipment may fail. When wastewater infrastructure gets coated in fats, oils and grease, often called FOG in the industry, the pipes can get clogged with fat as solid as butter and the treatment process can be compromised.  Then there was the time when the screening equipment – the first line of defense against incoming hazards – was adorned by hundreds of colorful pills that looked like Skittles.  

When something breaks, she has to get creative because it can be five-plus hours until help from the mainland arrives.  

The journey 

Lizzy was a typical Vashon kid, playing around the island’s bucolic lands and shoreline. She left to get degree in parks and resources management from the University of Montana, then came back to work as a seasonal temp for King County Parks on Vashon. For six seasons she worked the rotation, caring for parks during the summer and traveling the rest of the year. She knocked off the “Triple Crown” from 2014 to 2016, hiking across the country’s three major long-distance trails: the Pacific Crest, the Appalachian, and the Continental Divide.  

When a permanent position in Parks didn’t pan out, a King County colleague suggested the Operator in Training (OIT) Academy, a WTD program that takes the raw talent of people like Lizzy and helps them develop the well-rounded skills needed to operate these plants.  

“Through the OIT program, I got to experience it all,” she says. She was working in South Treatment Plant in Renton when the opportunity to come home to Vashon opened up. “We only have so many jobs on Vashon that can be done. An employment option like this is a crème de la crème opportunity.”  

Gregory Burnham used to run the Vashon Plant before passing the baton to Lizzy. “She brings to the table her sharp intellect, a strong sense of independence and responsibility, a ‘can-do’ attitude and great communication skills – which includes a sense of humor,” he says. You need to be self-sufficient, steady-footed, and confident to operate all the facets of a small treatment plant, he added. Lizzy’s got all that. 

Female worker with long blonde braid wearing safety glasses and hard hat looks out over Vashon Treatment Plant equipment from an elevated walkway.

Lizzy Corliss explains what the equipment does and how the treatment process works at Vashon Treatment Plant.

 These days, Lizzy runs the Vashon plant with the sensibilities of a local. She fields calls from people she knows, reporting what they see in the water or asking question about their pipes or septic tanks. “I’m super happy to stay in my hometown. I go to the grocery store and I see everybody,” she says.

Lizzy knows her work is essential to the health of the island – after all, businesses couldn’t function without the Vashon plant. “Every day I think, if we didn’t have wastewater treatment where would it all go? The plant, and my job, is the reason we have stores and restaurants,” she laughs.

Worker wearing bright orange safety shirt and hardhat stands near large concrete infrastructure at Vashon Treatment Plant.

The infrastructure of Vashon Treatment Plant is made inconspicuous in its wooded surrounds.

More information about Vashon Treatment Plant can be found here: