IOWA CITY, Iowa - The size and type of the fire at the Iowa City landfill make it especially difficult to deal with, according to a landfill fire expert.
At 7.5 acres, the fire would be considered large, said Tony Sperling of Landfill Fire Control Inc. His Vancouver, Canada-based company specializes in helping landfill owners put out and prevent fires.
Another complication, he said, is that what is burning is the landfill lining, which is made up of shredded tires. That means it's essentially a tire fire, he said, which are notoriously difficult to extinguish.
"You have a real problem with that," Sperling said.
The fire started at the city-owned landfill, located just west of town, on Saturday night. The city at this time is planning to let the fire burn itself out, saying that's the safest and most cost-efficient thing to do.
The media was allowed to tour the landfill on Tuesday. The fire has been contained primarily to an unused cell, which was burnt black and had small patches of fire scattered about. The flames were roughly 6 inches high.
Smoke was low to the ground and almost seemed to crawl out of the 160-acre landfill.
The fire measured at 1,200 degrees in some places, said Geoff Fruin, assistant to the city manager.
A cause has not been determined, but Public Works Director Rick Fosse said it most likely was something hot being brought in with a load during the day Saturday that was dumped on the edge of the active portion of the landfill. That could include something like charcoal from grilling or debris from a burn barrel, which some rural residents use to burn trash, he said.
Sperling and Jeremy O'Brien, director of applied research at the Solid Waste Association of North America, said so-called "hot loads" are the most common causes of fires in active landfills.
There are about 8,400 dump or landfill fires annually in the U.S., according a 2002 Federal Emergency Management Agency report. It was not immediately clear Tuesday if more recent numbers were available, but Sperling, who helped with that report, has said FEMA data showed there were 3,108 such fires in 2010.
Sperling, whom O'Brien called the "guru" of North American landfill fires, said most U.S. and Canadian landfills have a couple of minor fires each year that are put out within a few minutes.
By his count, there have been about 20 major landfill fires in the past decade. His company uses a numerical scale to rate fires, with level four being the biggest and reserved for those that take more two weeks to extinguish.
Iowa City is letting its fire burn out, a process city officials estimate will take more than week. Given that and the size, Sperling said it could rate a three or four on his scale.
The fire is primarily confined to an unused cell built a year ago, according to the city. It is burning a liner system made up of shredded tires, which is producing a plume of black smoke.
"That's a real shame. Those linings are expensive and are there to protect the environment," O'Brien said.
The city has set a preliminary damage estimate of $4 million to $6 million. The city is pursuing insurance claims and looking at other financial resources, including available funds and borrowing money, to pay for the cost, City Manager Tom Markus said. State and federal assistance also may be a possibility, Finance Director Kevin O'Malley said.
"It's a disaster to any degree," Markus said.
The landfill cell cost $7.8 million to construct, he said. The lining is ruined, Fosse said, but the same area should be able to be used for a new cell, he said.
There is about a year's capacity in the landfill cells that were not affected by the fire, Markus said
Tires that catch fire break down into hazardous compounds, including gases, heavy metals and oil, according to the U.S. Environmental Protection Agency.
Fosse said city officials are not concerned about leakage because there is a four-foot layer of compacted clay under the cell and a drainage system that collects runoff.
Public health officials have been taking samples and say air quality is not a concern at this time. People with lung and heart conditions or who are pregnant, older or have young children at home are advised to stay away from the smoke plume.
In the first couple of days after the fire started, the plume was moving north over scarcely populated areas. With a change in wind direction Tuesday, it shifted east, toward Iowa City.
The dark smoke was especially conspicuous in the nearly cloudless blue sky.
Q and A: Iowa City Landfill Fire
Q: How much longer is the fire expected to burn?
Fruin: There's really no set amount of days, we're going to first finish up with what we need to do on containment and then we're going to start to look at some extinguishing methods but at this point it's likely that we may just let it self-extinguish. After it's contained we'll look at opportunities to move dirt onto the places that aren't burning.
Q: Why has the department decided to allow the fire to burn out on its own?
Rocca: All the research that we've done related to this landfill cell fire and the nature of it being shredded tires indicates the best option is to let it burn, and I know it probably sounds contrary to what people might think.
It truly does burn as much of the toxins up as it can and disperses it into the air. And to do anything with extinguishing agents whether it be water or some type of foam while it would be labor intensive and very costly, there's also a runoff aspect and a concern to the environment and so right now research suggests to let it burn and so that's our best option.
Q: There's been speculation the fire started as a result of someone dumping hot coals in the landfill, is there anymore information regarding how this fire started?
Rocca: That's our best guess, clearly a hot load of something was dumped out here. We don't know exactly what it was and probably never will. There's no way to really monitor load by load or the contents of a load.
Q: The damage is now estimated to be between four and six million dollars. Who will take on those costs?
Fruin: It's a city owned property so that falls on us. We're working on insurance claims issues right now and we'll continue to work with the insurance company for a number of weeks and months to ensure the claims are filed appropriately.
Q: Do you have any concerns with methane gas being released into the air? What other kinds of environmental concerns exist?
Fruin: [The landfill has] a pretty sophisticated gas control system so we're able to turn it of and on and control that so we're pretty comfortable we're able to control that right now.
The one fortunate aspect is that [the fire] is taking place in a landfill cell so there is a complex filtration system so the runoff from the burning here did not penetrate much of the ground water. Our primary concern right now is the air quality and making sure that we continue to work with the Johnson County Health Department and the state DNR doing whatever we need to do to monitor the air quality.
Q: What role has the landfill played in containing the fire? Are any precautionary medical checkups being conducted?
Fruin: We're moving dirt to create some buffers. We needed to open up a couple of those old cells that still had capacity so we can continue to accept trash so they're removing dirt to open up the capacity for current use. Then we're utilizing that dirt and we're taking that to the back and the workers are using it to build buffers wherever the wind allows them to work.
We're certainly monitoring [the workers] very closely. We've got some masks that they're wearing and we're rotating the workers in and out throughout the day. [Worker safety is] certainly a big concern of ours and we'll continue to monitor it.
Q: After the fire has been put out and things have started to settle down, what is the plan for using the landfill again?
Fruin: It's probably premature to say exactly, but there will be some remediation and some cleanup that we'll have to get into and ultimately we'll look to rebuild the cell but that's a decision to be made down the road.