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Distant and cynical observers of landfill fires might be tempted to summarize such occurrences with the sentiment, “Nothing of value was lost.” Owners and operators of landfills, however, are keenly aware that a landfill fire is no trivial matter, and that the threats to human health, the environment and adjacent properties are very real.

A smaller scale landfill fire can lead to nuisance complaints and scrutiny from regulatory agencies. Larger and longer-lasting landfill fires have turned into legal sagas that can stretch over the course of several years.

A major contributing factor to these fires is the flammable and combustible material that is routinely sent to municipal solid waste (MSW) and other landfills. Landfill personnel on the lookout for these sources of trouble thus play a critical role in preventing the chance of a fire-related incident from wreaking havoc on a landfill site.

Trained and on alert

While landfill operations personnel are seldom the cause of a fire, they can play a decisive role in whether or not a fire breaks out or spreads.

“The most important tool to prevent hot loads is a comprehensive waste screening and load check program,” says Jason Todaro, the lead solid waste on-site trainer with Mariposa, California-based Blue Ridge Services. “This type of program needs to include all of the landfill staff, from scale house attendants to spotters and even equipment operators,” he adds.

"Staff should ask customers about the content of their loads. Ask customers questions like: Do you have any electronics or batteries? Do you have any fireplace ash or barbecue waste in your load,” –Jason Todaro, Blue Ridge Services

Todaro, who holds a California State Fire Marshall 480-hour Firefighter 1 certificate, says items that can be described as “hot loads” include barbecue equipment, campfire or fireplace ashes, and lithium-ion batteries.

While personnel should always be vigilant for these potential culprits, the summer season can be even more problematic. “Landfill fires tend to be more common between March and August, most likely due to an increase in dryer material and green/wood waste being landfilled,” says Todaro.

“In addition, there can be more hot loads, from barbecues, for example,” he continues. “And of course, a hotter ambient outdoor temperature can increase the likelihood of spontaneous combustion.”

Heat accumulation, the oxidation of some materials (including batteries) and the presence of methane gas all can play a role in what is labeled “spontaneous combustion,” according to a 2010 study by American and British researchers.

Regarding inbound material, Todaro suggests, “Staff should ask customers about the content of their loads. Ask customers questions like: Do you have any electronics or batteries? Do you have any fireplace ash or barbecue waste in your load?”

Visual inspection also plays a key role, says Todaro. “Landfill staff also need to keep an eye out for specific types of loads. For example, is the load coming from a campground (potential campfire ash)? Does the load contain a lot of canned chemicals, paints, solvents, etc., that could be flammable or create a spontaneous chemical response that could ignite?”

While it may seem obvious, Todaro says landfill employees should be trained to ask themselves, “As the load comes through the gate or is dumped and spread at the working face, is there visible smoke? Is there a burning smell?”

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It only takes a spark

The composition of materials arriving at a landfill means a certain percentage can serve as potential fuel if a spark or ember is introduced to this volatile mix.

As Todaro has noted, sometimes that ignition source is smuggled within incoming material in the form of an ember or volatile battery. Other times, however, internal combustion engine vehicles operating at the landfill or making deliveries to it can be the source of trouble.

“Trucks, compactors and other equipment can be a potential source of fire if they have a machine fire,” says Todaro. “If a fuel or hydraulic line breaks inside an extremely hot engine, it could then start the entire machine on fire. That machine could then ignite the waste.”

An analysis of highway vehicle fire causes collected by the U.S. Fire Administration’s National Fire Incident Reporting System from 2014 to 2016 found that 62 percent of such fires “originated in the engine, running gear or wheel area of the vehicle.”

The agency found that insulation around electrical wiring (29 percent) and flammable liquids in the engine area (18 percent) were common sources of trouble in highway vehicle fires.

Some of these problems also can occur in off-road vehicles or in the trucks delivering waste to landfills.

“One way to prevent machine fires is to have an onboard fire suppression system for heavy equipment and trucks,” says Todaro. “It also is really important for operators to do regular maintenance and remove debris and buildup in the engine compartment, undercarriage, wheels, etc.”

Another best practice involves where to deploy on-site equipment when it is not in use. “At the end of the day, equipment should be parked away from exposed waste,” states Todaro. “Ideally, heavy equipment would be parked on top of cover soil.”

Be prepared, but ask for help

Blue Ridge Services offers consulting, training and educational materials specifically pertaining to fire prevention and machine fires—among many other topics.

Todaro says the training aspects of responding to a landfill fire, however, emphasize that “it is important to recognize that landfill staff are not first responders.” The same employees who are alert and vigilant should not necessarily be asked to combat a fire themselves.

"While there are situations where landfill staff can fight fires, it’s important to have very clear guidelines about when staff should and shouldn’t [do so],” –Jason Todaro, Blue Ridge Services

“While there are situations where landfill staff can fight fires, it’s important to have very clear guidelines about when staff should and shouldn’t [do so],” states Todaro.

The Occupational Safety and Health Administration (OSHA) “has some guidelines on what is called an incipient fire, which is a fire that is in the ‘initial or beginning stage and which can be controlled or extinguished by portable fire extinguishers, class II standpipe or small hose systems without the need for protective clothing or breathing apparatus,’” says Todaro.

When Blue Ridge works with clients to create fire safety plans, the company uses that OSHA definition “as a clear guideline of when staff should fight a fire and when they should not,” adds Todaro.

It is landfill owners and managers who can lay the groundwork for successfully fighting a landfill fire, in part by establishing a relationship with the fire department in the landfill’s jurisdiction.

“We do have clients that involve local fire departments in the fire plan for their landfill,” says Todaro. “We definitely recommend this because firefighters, in general, are more experienced with structure fires, vehicle fires and wildfires, but very few have ever dealt with a landfill fire, especially if it is a subsurface landfill fire.”

Surface fires and subsurface fires can be different animals, says Todaro, that can “respond differently to weather conditions, like high winds.” Subsurface fires can be problematic in the long term, as was demonstrated in Missouri last decade. (See the sidebar “Smoldering resentment.”)

An analysis of several dozen landfill fires by a government agency in the United Kingdom found that “approximately 57 percent occurred below the surface of the waste and 13 percent occurred at the surface. A further 27 percent were the result of bonfires, suspected arson or similar causes.”

Todaro’s advice to all landfill owners is, “It would be very worthwhile to bring your local fire department out to your site, even if it is just to give them a lay of the land.”

Such visits, says Todaro, can allow fire departments to determine the answers to such questions as: “Where is the water tank? How do they get to the active face? How do they access the site if it is the middle of the night?”

That knowledge, Blue Ridge has found, can help prevent a minor- or medium-sized problem from escalating into a major one. “Once the fire goes beyond the incipient fire stage, the fire department must become involved, and it is better that they have some knowledge of how to best deal with a landfill fire,” says Todaro.

Landfills may not hold much of value within them, but an alert staff and an informed local fire department can be critical in preventing them from becoming a potential environmental, legal and financial liability.

The author is a senior editor with Waste Today and can be contacted at btaylor@gie.net