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    Credit: Rick Zettler

    Fire in a cell lined with shredded tires generated 40,000 square yards of debris for the Iowa City Landfill and Recycling Center in Johnson County, Iowa. Water won’t extinguish burning tires, so heavy machinery was brought in to level and cover the smoldering piles of material with clay.
 

Regardless of how many precautions are taken, cell fires sometimes occur. When they do, how landfill managers react during and immediately afterward goes a long way toward mitigating the effects and reducing cleanup costs.

Last year, the 400-acre Iowa City Landfill and Recycling Center in Johnson County, Iowa, wrote a new chapter in the manual on how to successfully combat a fire. The facility receives 400 tons of municipal solid waste per day generated by the businesses and citizens of Johnson County, Kalona, and Riverside, Iowa.

The fire started in a relatively new 14-acre cell that included the landfill’s common lining and leachate collection system. Instead of placing sand over the leachate lines, managers had lined the cell’s floor with a 3-foot drainage layer of shredded tires, an environmentally friendly but ultimately problematic option. With one-third of the cell covered by mid-May 2012, it was on track to be fully covered by winter.

The schedule was significantly sidetracked on May 26, 2012, however.

As usual, the landfill closed at 4:30 p.m. Saturday and workers covered the day’s intake with a soil cap.

Then the improbable happened.

Fire in the landfill!

“We received a call at 6:45 p.m. that a fire had started in the cell,” says Tom Hansen, equipment superintendent for the City of Iowa City. By the time employees returned to the site, it had spread to the recycled tires. To this day, the cause remains undetermined, but speculation points to something smoldering in a load of refuse accepted that day.

“Our employees and the Iowa City Fire Department attempted to control the extent of the burning material by dozing fire breaks through the shredded tires and liner to bare ground,” says Landfill Superintendent Dave Elias. However, the heat, gases, and oil generated by the burning tire material followed leachate lines to emerge behind the breaks.

For nine days, the tires burned while officials took various measures to try to extinguish the flames.

“This was unprecedented,” says Hansen. “Water isn’t effective on burning tires. We tried using foam with no success, then reached out across the country for solutions.”

At the same time, they worked with the Johnson County Health Department, State Hygienic Laboratory at the University of Iowa, and EPA to monitor air quality. Multiple samples were taken throughout the city and analyzed during the event to advise nearby residents and ensure their safety. No major air quality issues were reported.

On June 4, the fire department and landfill started a “stir, burn, and cover” operation. Heavy machinery was brought in by an outside contractor to level the piles of burning tire shreds and cover them with a layer of clay to suppress the burning.

It took almost a week to complete the process over 7.5 acres of tires. Even then, the fire wouldn’t totally extinguish. “There were hot spots for several weeks, but the process eventually smothered the fire,” says Hansen.

Managers then focused on the next phase: debris removal.

That meant removing the top layer of clay — the equivalent of 1.3 million charred tires and ash — as well as part of the liner. After asking local contractors for time and cost estimates, managers went with a strategy they’d used in the past to save the money.