What does it take to fight fire from the air?
Glenwood Springs Post Independent
WHAT IS SLURRY?
Slurry used to fight wildland fires is “basically fertilizer,” according to Clinton Bellingar, Single Engine Air Tankers (SEAT) manager at the Rifle-Garfield County Airport, where fire-fighting air operations for the region are based.
According to the U.S. Forest Service Interagency Wildland Fire website, the material is made up of about 85 percent water, 10 percent fertilizer (ammonia phosphate and sulfate ions), and 5 percent iron oxide, clay or bentonite for coloring)
“Aerially applied fire retardant and other fire chemicals reduces wildfire intensity and rate of spread, decreasing risks to firefighters, enabling them to construct fireline safely,” according to the site. “In many situations, the use of retardant in concert with firefighters on the ground allows the Forest Service to safely meet its responsibilities to protect landscapes, resources, and people.”
Although the slurry mixture doesn’t have much of an environmental impact, crews won’t drop near water sources, Bellingar explained. It’s never dropped within 300 feet of waterways, he said.
At the Lake Christine Fire on Wednesday, crews dropped a total of 52 loads of slurry, coming out to around 35,000 gallons.
One SEAT holds around 800 gallons of slurry, and as of Tuesday, the day the fire started, one load of slurry cost $5,207.98, according to Chad Johnson, another of the supervisors at the Rifle facility.
Since the Lake Christine Fire broke out Tuesday, Roaring Fork Valley residents have seen or at the very least heard aircraft and helicopters zoom by as they work to contain the fire and prevent its spread.
On Friday, 214 fire personnel were working the fire with six hand crews (roughly 20 people per crew), 18 engines (varies with three to five fire personnel), two Type 2 helicopters, two Type 1 helicopters and a light helicopter that is used mainly for reconnaissance work, according to Friday’s on-duty public information officer Pat Thrasher.
One of the heavy Chinook helicopters used to fight the fire also has been stationed out of the Glenwood Springs Municipal Airport, according to Amy Helm, manager of the small airport south of town.
Friday was the first day that Single Engine Air Tankers, or SEATs, were not used to drop slurry, or retardant, on the fire line, though four were stationed at Rifle Airport on Friday just in case.
“We are supporting ground personnel, they are doing the hard work,” SEAT pilot Bob DeRosier said. “Anytime we can clear them to save structures, that’s what we are there for.”
While the SEATs were not necessary Friday, the tankers were used to drop slurry on the fire’s boundary to help solidify the fire line and allow ground crews access to the area.
Though helicopters can be seen dropping buckets of water or through long tubes extending from a water tank directly onto the flames, slurry is not dropped directly on the fire and instead is used to stop the spread.
David Boyd, area Bureau of Land Management spokesman, said the tankers are only effective when they can work in tangent with ground crews.
SEATs went out immediately after the first spark ignited the Lake Christine Fire, and continued up until Thursday.
On Wednesday, there were as many as seven SEATs flying in and out of Rifle Airport to refill slurry to drop on the fire line, according to SEAT Manager Clinton Bellingar.
He said they made a total of 52 loads of slurry that day, coming out to around 35,000 gallons.
DeRosier, who was one of the first SEAT pilots on the Lake Christine Fire, said that the slurry is dropped out at 120 miles per hour and takes about three to seven seconds to drop.
Helicopter Supervisor Chad Johnson said the receipt showed one load of slurry cost $5,207.98 on July 3. One SEAT holds around 800 gallons of slurry.
Johnson said that because of conditions this week, the retardant was not super effective, though “it definitely helped, and I’m positive it made a difference. There would have been many more structures lost without it.”
Another aircraft that helped keep the fire contained was the DC10 Tanker, one of two in the nation, which was used on the Fourth of July to assist on the Lake Christine Fire. The DC10 holds about 20,000 gallons of slurry and is much faster than the SEATs.
While the slurry prevented the fire from burning more structures, DeRosier said the terrain made the Basalt fire particularly difficult to fight.
While flat land is pretty straightforward to drop retardant on, when the fire is on a slope, like the one in Basalt, the tanker had to come in from above and match the slope so the slurry is dropped exactly where the crews want it to be.
Because the slurry is mixed at the Rifle Airport, pilots had to return back to refill on retardant before dropping another load.
Boyd said the SEATs were going on roughly hour-long round trips to drop on the Lake Christine Fire and return, though that includes coordinating with air command and the lead plane to ensure the slurry is dropped exactly where the ground crews want.
While the SEATs and other tankers are used to drop slurry to try to create and maintain a fire line, Type 1, 2 and 3 helicopters are used to drop water directly on the fire and transport ground crews in and out. The smaller the type number, the larger the helicopter.