CASCO, Maine - As huge saws rip through logs at the Hancock Lumber sawmill, sawdust flies through the air and coats equipment, floors, and rafters. Far from a nuisance, though, the sawdust is commanding premium prices as housing construction slumps and energy costs grow.
Nationwide, the price of sawdust, along with that of other wood byproducts, has soared.
When they can find it, sawdust buyers - dairy farmers, particleboard makers, and wood pellet manufacturers among them - are paying up to $50 a ton or more, double what they paid a year ago, some say.
Once, sawmill operators could barely give away their dust. These days, they have ready markets for sawdust, as well as bark, wood chips, and board trimmings that can't be sold as lumber.
"Now the only things in a sawmill that aren't salable are the whine of the saw blade and the steam from the kiln," said Peter Lammert, a forester for the Maine Department of Conservation who tracks the industry.
At the Hancock Lumber sawmill, logging trucks arrive daily loaded with eastern white pine logs. As they go through the mill, the logs are debarked, cut, sized, planed, graded, and sorted as they are transformed into lumber.
And, sawdust and wood chips fly. Much of it falls through metal grates onto a system of conveyor belts that carry and separate all of the leftover wood byproducts, all of which are sold for different purposes. The bark becomes mulch for landscaping; the shavings are used for animal bedding; larger scrap pieces are used in biomass power plants.
The bulk of the byproducts is sawdust, which is blown through a metal pipe into a storage shed, which on a recent March day was filled with a 20-foot-high mountain of sawdust that sawmill manager Mike Shane estimated weighed about 150 tons.
In the cold months, the mill uses the sawdust to power its own furnace for heat and to run its kilns that dry the lumber. But when the weather warms up, it sells its supply to dairy farmers for animal bedding and to plants that manufacture wood pellets that are burned in wood stoves and furnaces.
In the past year or so, the price has roughly doubled, Shane said. "A truckload of sawdust has gone from $600 to $1,200," he said.
In the first three months of the year, US sawmills have been shipping about 114 million board feet of lumber per day, said Henry Spelter, an economist with the US Forest Service forest products laboratory in Madison, Wis. That's down from 135 million board feet per day in the year-ago period, and 160 million board feet in 2006.
At the same time, wood pellet plants are popping up in need of raw supply, thereby increasing the demand, he said.
"When the housing market comes back and the price of lumber goes up, the price of sawdust should go down," said Ralph Caldwell, who owns 400 dairy and beef cows at his Caldwell Farms in Turner, Maine.