If you’re downwind of Kennewick’s waste treatment plant, you could be in for a rude awakening.
A problem at a downtown Kennewick settling lagoon forced the city to declare an emergency to keep sewer and waste water from flowing into the Columbia River.
The City Council scrambled Tuesday to approve a $2.2 million contract with Merrell Bros, a biosolid management company, to dredge the two lagoons at the treatment plant. By declaring an emergency, the city saved time by not having to following the normal bidding process.
Work is expected to start this week.
Evelyn Lusignan, the city’s public relations and customer service manager, said the need for routine maintenance combined with unforeseen problems to create the problem.
When sewage flows into the treatment plant, it lands in one of two lagoons, where solids settle to the bottom and combine with microorganisms that convert the material into something similar to compost.
The process is nearly complete in Lagoon 2, and officials planned to remove the solids this year. Not wanting to contaminate the treated biosolids, the city sent the new effluent into Lagoon 1.
Then the long, cold winter caused the biosolids on the bottom of Lagoon 1 to float to the surface, leaving a sludge that threatened to contaminate the water running into the remaining portion of the process.
“Normally we have the flexibility to switch between Lagoon 1 and Lagoon 2,” Lusignan said. “But we don’t want to mess with the solids that we have in Lagoon 2.”
The system is not set up to remove solids from the water before it is discharged into the Columbia River.
The city and the state Department of Ecology developed a plan to dredge a portion of Lagoon 1, and place the biosolids on a liner for three to four months to dry.
It’s likely the material will produce a strong odor near the treatment plant, depending on the wind, city officials said.
It’s unknown whether the smell will be weaker or stronger than the odor coming from the plant now.
Along with removing the sludge from Lagoon 1, officials also accelerated plans to remove the solids from the second lagoon.
Merrell Bros is the same company the city used in 2012 to take biosolids from the plant to be used for fertilizer on a nearby farm.