Unless the weather cooperates, smoke from two smoldering compost piles at the Rapid City Landfill could continue to plague residents living in and around the city for a few more days.
Over the past week, strong winds have hampered efforts to douse the smoking mass of yard waste that ignited on May 16.
"There is a misconception that this is garbage burning," said Public Works Director Terry Wolterstorff, during a tour of the area. "This is definitely not garbage."
The Rapid City Fire Department has fielded about a dozen calls about the smoke. The mayor's office has also received calls, Wolterstorff said.
The Environmental Protection Agency in Denver received an anonymous call about the fire, according to Solid Waste Superintendent Karl Merbach. Those concerns were forwarded to the state's Department of Environment and Natural Resources, he said.
But, there's really nothing that can be done other than to continue breaking the pile apart to cool the hot spots and drown hot embers, Merbach said.
On Friday, a front-end loader took 6-yard bites out of a towering pile of smoking compost, while a water truck stood by shooting bursts of water on the scattered compost. The hose was frequently turned on the giant pile when smoke billowed from newly exposed surfaces and the north winds fanned new pockets of flames.
The cause of the fire is unknown, but it is not uncommon for small spontaneous fires to break out in composting materials, according to Lt. Brent Long of the Rapid City Fire Department.
"We come out here a few times a year," Long said Friday when a fire truck arrived to soak some of the burning embers with a compressed air foaming agent that helps make "water wetter," he said.
Landfill employees successfully separated the finely ground yard waste from a pile of course yard waste consisting of tree branches, trees, shrubs and grasses were the fire started. Stretching from north to south, the piles are each approximately 150 yards long.
Plumes of smoke rose from each pile.
The finely ground compost is getting the most attention, because it is producing most of the unpleasant smoke.
Once the loader digs a bucket of compost from the big pile, it is scattered and hosed down to extinguish any embers. When a pile is fire-free, it's loaded into a dump truck to be hauled to a nearby site to join rows of compost waiting for a final sifting. The landfill sells the sifted compost.
Firefighters helped monitor the massive piles around the clock, until Tuesday. Landfill and city workers have continued to work the piles, with help from other city crews. The piles are monitored around the clock.
Work was progressing well at dousing hot spots and stirring the piles until the wind started to pick up on Thursday. Winds gusting up to 39 mph fed the smoldering embers.
Water will only penetrate so far into the smoldering mass, so just pouring water on the piles will only cool the surface fires, Long said.