The La Conner wastewater treatment plant, whose construction a half-century ago led to a sustained period of commercial and residential growth here, is in line for a makeover costing millions within the next five years.
It’s a hefty project for the Town, whose entire 2025 budget was $7.7 million. The plant is near capacity, aging, and costly to maintain, with parts harder to find and new science showing its discharges can harm Puget Sound. Rising sea levels and increasingly common high king tides also put the plant at higher risk of flooding.
“The most important issue is how to pay for the necessary upgrades,” said Scott Thomas, Town administrator. “We don’t yet have an answer (we won’t know what a plant will cost until we have a preliminary estimate). As the process unfolds, we will be in a better position to answer that question as well.”
From planning to construction
The Town is almost finished with its preliminary project plan, paid for with a state Department of Ecology grant, which will lay out options for revamping the aging plant.
“Once we get the report in,” Thomas said, “we’ll have discussions about what type of plant and treatment we’ll have.”
Those discussions will involve plant stakeholders, including the Swinomish Indian Tribal Community, he said.
After that, Thomas said, a new plant design will be approved based on the treatment type selected, proposed flood mitigation measures, and the amount of space needed for anticipated expansion.
“We’ll be looking to the state for grants to do the design work,” Thomas said.
Finally, the project will go out for construction bids.
Keeping the current plant running
For now, operators with Water and Wastewater Services, the firm contracted to run the La Conner plant, conduct daily preventative maintenance while the upgrade plans gradually take shape.
“We work with urgency and care,” stressed operator Taylor Loza, “for our public and commercial wastewater and compost customers.”
Still, the operators can’t help but look forward to the future given present challenges of nursing along a plant infrastructure dating to the Disco Era.
“The most important issue is how to pay for the necessary upgrades.”
-Scott Thomas
“We’re really excited for the upgrade,” said operator Kamryne Pressgrove, who explained that tertiary treatment — to which municipalities are increasingly turning for optimal water quality and sustainability — engages an ultraviolet disinfection process for removal of contaminants.
From septic to soil enrichment
The concept of tertiary treatment emerged in the 1970s, just as La Conner was transitioning from a septic system to secondary treatment with construction of the plant near the west end of Chilberg Road. Today, tertiary treatment is recognized as the final stage of wastewater treatment, involving advanced filtration and chemical treatment in addition to disinfection.
The timing of the La Conner secondary treatment plant’s construction couldn’t have been better. Fifty-one years ago, the town was dotted with septic tanks and meandering ditches that occasionally filled with odorous and dark mucky water. Upgrading to a secondary system not only improved local water quality but 90% of the plant’s construction costs were covered then by the federal Clean Water Act.
In recent years, the La Conner plant has gained much notoriety and generated an added revenue source for the Town by composting biosolids to create a soil enrichment product sought by both commercial and residential customers. The plant receives septage from throughout the area, producing useful biosolids and literally turning those sludges into cash.
Bill Reynolds is a general assignment reporter who covers Town government, schools, and spot news.
