An Everett, Washington, treatment plant discharged approximately 10 million gallons of wastewater into the Snohomish River.
According to HeraldNet, the state Department of Ecology investigation notes that the city officials do not allege significant impact to people, animals or the ecosystem. The wastewater did not meet disinfection standards, however.
According to Jeff Marrs, Everett’s public works operations superintendent, the wastewater went through every other step of treatment, however, noting that it wasn’t raw sewage getting dumped into the river.
The weekend of the discharge (June 4-5) , the plant handled over 63 million gallons of mostly storm water, reported HeraldNet. The grit and grime were filtered, the feces was separated, and scum was scraped.
According to HeraldNet, for 19 hours, during the last step of treatment, sodium hypochlorite was not getting injected properly. Marrs said this step was more “post-treatment” to kill lingering bacteria after everything has been filtered.
To mitigate the issue, operators reprimed the pumps to push the air out, reported HeraldNet.
According to Marrs, air got into the chemical feed pumps, impacting the ability to inject the chlorine solution into the water, yet alarms were not going off to indicate the pumps had completely stopped.
It is anticipated that the facility will install a new sensor that can measure the concentration of chlorine in the water.
The Everett Water Pollution Control Facility handles an average of 20 million gallons of outflow a day and can handle more than 100 million gallons, reported HeraldNet.
Since 2021, there have been three notifications including the recent discharge, according to Marrs, reported HeraldNet.
Operators do quarterly inspections of the flow switches if the chlorine solution is not getting pumped into the wastewater.
