MONROE — The city of Everett is still investigating what caused a less-than-year-old roof to collapse at a water filtration plant it operates. The damage came after a series of winter storms brought record snowfall.
The site provides drinking water for approximately 75 percent of businesses and residents in Snohomish County. In 2017, the Everett water system supplied over 19 billion gallons.
Testing has shown the water remains safe to drink. The filtration plant sits at the southern end of Lake Chaplain, northeast of Monroe.
“We don’t know what happened. We’re still in the investigatory stage,” said Kathleen Baxter, a spokesperson for the Everett’s public works department. “Nothing has been ruled out yet.”
The damage was discovered early Feb. 12 during a routine check, according to Baxter. The next day, city staff and the contractor who built the roof came to examine the structure.
The water filtration plant delivers an average of 50 million gallons of drinking water per day and can treat up to 141 million gallons each day, according to the city.
After treatment, water is sent to one of two large storage basins known as clear wells.
“The clear wells (provide) a buffer between demand and production,” Baxter said.
It was the roof of the east clear well that sustained damage. The structure, which can hold 5.2 million gallons, was built in 1983. In August, the 35-year-old roof was replaced by contractor T Bailey, Inc. The Anacortes firm designed and built the project for $3.1 million. A warranty was included in the contract. T Bailey didn’t respond to calls for comment.
After the collapse was discovered, the east clear well was removed from service. In that process, the two clear wells were disconnected from each other.
There was no damage to the west clear well. It can hold 6.75 million gallons.
Although about half of the water filtration plant’s storage capacity was taken offline, the city said it still has enough to serve its customers.
“Everett’s water system has redundancies built in to prepare for situations like this,” Baxter said.