A small hay squeeze-loader carrying a stack of bales away from the flaming “mega-stack” is silhouetted by the bright-hot fire at Haykingdom Inc. at the southwest of Old Highway 111 and Worthington Road east of Imperial on Saturday morning, June 12. | CAMILO GARCIA JR. PHOTO
IMPERIAL — Haystacks and drummers in Spinal Tap are a lot alike — sometimes they just spontaneously combust.
That’s what seasoned fire investigator and Imperial County fire Battalion Chief Juan Rodelo suspects might have happened when a 2,500-ton “mega-stack” caught fire overnight Saturday, June 12 on the southwest corner of Old Highway 111 and Worthington Road east of Imperial.
The stack, which was left to burn once exposures were protected and made safe, was expected to continue to smolder for at least a week.
In the 1984 comedy “This is Spinal Tap,” the English rock band couldn’t keep a drummer, losing at least a couple to the mysteries of spontaneous combustion. Yet in the case of haystacks, most firefighters and hay brokers know, there is some serious science happening inside those compressed stacks of organic matter.
Rodelo’s theory isn’t rock solid at the moment, he said, but as he arrived first on scene to the 2:43 a.m. call, his experience as one of county fire’s main investigators had him scanning the area for any suspicious clues. He said he saw none and the engulfed stack was behind a secured fence.
“We didn’t see anyone around, no vehicles leaving the area,” Rodelo said on Saturday midday as the stack was still burning steadily. “The fence was locked; we had to cut it to get in.”
Although haystack fires are usually allowed to burn themselves out, it was a frantic pace from the time of the call to about 6 a.m. when some 25 fire personnel along with about a dozen employees of Haykingdom Inc., where the fire was situated, worked to protect other stacked bales in the vicinity and exposures.
A third alarm was sounded to bring in additional water tenders and manpower as seven engines and crews from El Centro, Calexico, Holtville, Westmorland, Brawley and Naval Air Facility El Centro fire departments assisted Imperial County fire Station 1 personnel.
Rodelo said Haykingdom workers used forklifts and hay squeeze-loaders to quickly move bales to areas farther away from the fire site while firefighters cooled down nearby stacks to bring down the ambient temperature and douse flying embers and burning hay around the central mega-stack.
Water and fully engulfed haystack fires do not mix, so no water was ever applied directly to the burning stacks, Rodelo said. Wet stacks can prolong the time it takes for a fire to burn out, according to fire officials interviewed for previous stories.
Fortunately, weather conditions over the next week should be favorable for the smoke staying in a tight column and drifting straight upward, Rodelo indicated.
In fires like this, Rodelo said he was on the phone with the Phoenix office of the National Weather Service to get hourly reports on temperature, wind speeds and direction, humidity and other information that allow fire officials to accurately forecast how the smoking stacks will affect the air quality.
Rodelo said there is no inversion layers or serious winds expected during the duration of the burn, according to the information he obtained from the National Weather Service.
Meanwhile, as they continue to assess the cause of the fire, Rodelo said it’s likely this blaze will be chalked up to “undetermined suspicious” causes, as there won’t be much evidence left to collect at the end of the burn.
Returning to Spinal Tap theory, it’s surprising more of these large stacks do not go up in smoke due to the forces of nature occurring within them. But Rodelo said hay companies and farmers are quite experienced in this and know how to keep their bales safe from the biological processes that can ignite a stack.
The science is simple yet complex. Rodelo explained that these mega-stacks are comprised of sometimes moist or wet hay in which bacteria grows and organic matter breaks down and begins to decompose. In that chain of events, the chemical reactions of decomposition give off heat, which is compounded by the daytime temperatures.
Combustion temperatures of between 448 degrees and 527 degrees Fahrenheit can be achieved over time after the decaying matter exceeds temperatures over 175 degrees, according to a document Rodelo shared on the science behind hay fires.
The document, which looks to be intended for ranchers and hay companies, warns to look for stack temperatures over 150 degrees, the “beginning of the danger zone,” to 212 degrees, the point at which “hay will almost certainly ignite.”
Still, Rodelo said the department is looking into causes of the blaze.