Clouds of smoky steam billowed yesterday from the stump fire in western Baltimore County as firefighters sprayed a foam solution expected to eventually put out the blaze, which has spread to the entire 7-acre dump.
A Missouri expert hired to put out the fire at the Patapsco Valley Tree Farm in the 8700 block of Dogwood Road said extinguishing the blaze would take longer than the 10 days he had originally estimated.
However, he remained confident that the foam would work faster than tearing apart the smoldering rubble and dousing it with water, as firefighters have been doing for nearly two weeks with little success.
"The foam is already penetrating the fire and cooling it by converting it to steam. It looks real good so far," said Richard McCann, owner of the Kodiak Team Foam Fire Co., as he scanned the mist rising from gigantic lumps of charred wood.
It will take at least 48 hours before fire officials can determine whether the foam is working. Baltimore County hired Mr. McCann's firm to spray the foam for 10 days at a cost of $23,000.
Mr. McCann said he will have to stay on the job longer and use 10 times more foam than expected, but wasn't sure how much more time he will need or how much more his services will cost.
The stubborn fire was discovered Feb. 2 in the dump, which is as wide as a football field, three times as long and rises as high as 75 feet in places, with rubble buried as deep as 30 feet under the ground.
It started in a pile of stumps at one end of the dump, and firefighters had hoped to contain it by digging a 14-foot trench in front. But aided by the wind, the fire moved under the trench to ignite stumps on the other side.
"The more the wind blows, the hotter it gets [and] the more the fire is driven onward," said Mr. McCann, explaining that the entire mass of wood debris is now being consumed in a fire churning 100 feet under the rubble at some places.
"This fire is so large that we can only work the hot spots," he said. "It's grown four times as large since we surveyed it just days ago."
But he said he still believes his foam solution, Phos-Chek WD-881, will work.
Mr. McCann said his main concern at this point is that the underground fire could breach the surface, perhaps causing the collapse of an access road and igniting other fires above the ground.
Last fall, his firm applied the foam on a similar stump fire in Kansas City. Fire officials there said it helped suppress the fire but did not put it out completely.
Ervin Ross, acting deputy chief of the Kansas City Fire Department, said officials at first thought the foam extinguished a fire they had been fighting for three weeks. But three weeks later, the stumps began smoldering again. Firefighters had to return six times before they finally put out the fire.
While the battle with the fire continues, the good news for area residents is that changing weather conditions have reduced the amount of smoke the fire is spewing over the metropolitan area even as the blaze spreads.
For the first few days after the fire was discovered, thick smoke turned the sky gray and created discomfort and health problems for area residents and people working outside.
Weather experts attributed this to a quick change in temperature that left cold air filled with the smoke trapped below a layer of warm air. Changing weather patterns in recent days have allowed smoke to dissipate.
While much of the Patapsco Valley area was again covered with gray haze yesterday, fire officials say it looked worse than it actually was.
"What you see out there is not smoke, but a huge steam cloud," said David H. Filbert, chief of the county's Bureau of Air Quality and Waste Water Management.
"The foam has a high moisture content," he said. "When it's applied to the fire, it gives the impression that there is more smoke in the air, but that is not the case."