Investigators are trying to determine what caused a pile of scrap material to catch fire for the second time in seven weeks.
The Pueblo Chieftain reports thick smoke from a Sunday afternoon fire at the American Iron & Metal scrap yard caused a temporary highway closure and health advisory asking residents to seal their homes.
The highway was reopened and the advisory lifted Monday.
Pueblo Rural Fire Chief Bret Marscola says officials with the Environmental Protection Agency are testing air quality through the next few days.
Water used to fight the fire ran into Salt Creek, which is also being monitored.
The same pile of scrap material caught fire April 19.
Marscola said an EPA investigation will decide if the scrap yard owners are fined.