The U.S. Environmental Protection Agency has taken command of a Fountain-area tire fire that is emitting "extremely poisonous" smoke, is expected to contaminate Fountain Creek and spurred the closure of an elementary school Tuesday.
But the blaze must burn itself out, officials said.
The tires' steel wheels are so hot that firefighters can't cool them and extinguish the blaze, which likely will continue emitting toxic smoke for the next week.
"At some point, you have to say it's best to let itself burn to the ground," Jim Reid, executive director of the El Paso County Office of Emergency Management, told county commissioners Tuesday. "Since there are no lives immediately at stake from the fire, we can do that."
EPA officials were investigating how far the toxic chemicals have traveled.
Depending on their findings, more people might have to evacuate the area. Three houses remain evacuated now from within a half-mile of the blaze, Hanover Fire Chief Carl Tatum said.
"We want to relocate them out of the area so they are not exposed to hazardous chemicals and first responders also are not exposed," Reid said.
The only part of the 3,300-acre Carson Midway Fire still burning is a wall made of hundreds of old tires, rocks and dirt.
On fire, each car tire burns the equivalent of 4 quarts of oil, while each commercial tire burns 2 to 2½ gallons, Reid said.
The burning tires emit toxic chemicals such as polychlorinated biphenyls (PCBs), chromium, zinc and other heavy metals.
"The black smoke is extremely poisonous," Reid said.
Residents within a half-mile of the fire near the 20800 block of Prairie Fire Point should "consider leaving the area if they begin to experience health impacts such as nose or throat irritation or if they have underlying cardiovascular conditions that may be aggravated by smoke," says a Monday news release from the county.
The tire fire prompted officials to cancel classes Tuesday at Prairie Heights Elementary School, 7930 Indian Village Heights, "to allow thorough inspection of the building for possible smoke impacts," the release said.
School resumes Wednesday, said county spokesman Dave Rose.
School officials had been concerned that the HVAC system might have turned on and drawn smoke and other contaminants into the building. But the system had been turned off for the weekend, Rose said.
Debris from the fire and trash pits in the community likely will contaminate Fountain Creek, however, Tatum told county commissioners.
"The Midway Ranch area is an arid wetland, so when we have a downpour, all that contaminated rain water will be dumped into Fountain Creek," Tatum said. "It may not happen today, or a year from now, but it will happen."
He urged commissioners to work on legislation that would make tire fences and trash pits illegal.
"There's nothing that forces them to clean this up, and we don't know that they're there until we stumble across them while fighting a fire," he said.
Darryl Glenn, president of the county commissioners, asked Reid to draft a list of actions for the county to address on the issue.
The Gazette's Rachel Riley and Ellie Mulder contributed to this story.