WHITE CITY — For the second time in four days the massive bark pile at Biomass One in White City caught fire and sent a plume of smoke above the Rogue Valley.
The fire sparked at around 6 p.m. and forced Jackson County Fire District No. 3 to issue a second alarm when flying embers started a small grass fire in a nearby property.
Crews shut down Avenue G between Agate Road and Highway 62 as they blasted the flaming sawdust hill with high-pressure hoses.
Biomass One is a 30-megawatt, wood-waste cogeneration plant that annually recovers 355,000 tons of wood waste, according to the company website. The recovered wood waste then is turned into electrical or steam power. The company also sells bark chips for landscaping.
District 3 Fire Marshal Hugh Holden said the pile caught fire after microbes within it broke down the sawdust and caused heat to be trapped beneath the surface.
The sawdust pile acts the same way as a compost pile, meaning it's not uncommon for it to trap enough heat to catch fire in hot, dry weather, Holden said.
"The concern for us is the depth of the pile," Holden said. "It helps contain the heat for a long time."
Oregon Department of Forestry crews were called in to monitor nearby grassy areas. Holden said small embers were seen drifting from the pile and traveling across Avenue G.
"Fortunately, these embers aren't very large and don't travel far," he said. "However, they do travel."
No structures were damaged, Holden said.
Crews from the Medford Fire Department and the Medford airport helped District 3 firefighters hit the blaze with water from multiple sides.
The fire produced a large amount of smoke in a short time, with flames poking through haze near the top of the pile.
Jackson County sheriff's deputies routed traffic around the area, creating a brief snarl on Highway 62.
"You don't want to drive in the area when there's a fire like this," Holden said. "It's best to stay clear of the area."
The same pile caught fire Saturday evening and threw up a large column of smoke that was visible from Medford.
Holden said fire crews would probably remain at the scene throughout the night, monitoring the pile in case it erupted again.
"We'll be out here for a while," he said.
Reach reporter Chris Conrad at 541-776-4471 or email firstname.lastname@example.org.