In early November 1999, landfill owners at the Delta Shake and Shingle Landfill in North Delta, Canada, sounded the alarm. It was just about midnight when smoke began to fill the air. A 250,000-cubic-yard cell in the landfill had erupted in flames. The landfill operator tried to put out the fire, but initial efforts only accelerated combustion of the construction and demolition (C&D) waste.

A few weeks later, with the landfill still burning, the city became worried. Smoke from the fire began to cast a thick haze over the nearby Vancouver skyline. Streams in the area were threatened by leachate pools forming from the firefight, and workers on adjacent properties were being affected by smoke and odors.

On November 27, Delta's Mayor declared a state of local emergency, and the British Columbia Fire Commissioner ordered the Delta Fire Department to extinguish the blaze.

But quelling a landfill fire is not that simple, firefighters found. Complicating their efforts was the presence of a high-pressure natural gas main that provided heating fuel for nearly half-a-million customers in Vancouver, as well as a large-volume sewer force-main, a water supply main, a high-voltage transmission line and a railway line. All of these utilities were located adjacent to the landfill in unstable peats, and were potentially threatened by slope failure or excessive settlement.

Additionally, careful attention had to be paid to the geotechnical design and monitoring of the areas on top of and adjacent to the landfill to avoid stressing or displacing the nearby gas pipeline.

With these things in mind, the fire department created a strategy to close the 200-yard by 200-yard burn zone, rapidly construct PVC-lined cool down areas on expropriated property, excavate and wet down the burning material, and ultimately replace the extinguished material back in the landfill.

Nary a Spark The Delta Shake and Shingle Landfill is a privately run C&D facility located in North Delta, near Vancouver, British Columbia. Developed on a soft foundation, including organic peats, unconsolidated clays and silts, the landfill began operations in 1989. It was permitted to receive 20,000 tons of waste per year. And by November 1998, almost the entire 32-acre footprint was covered with waste to a height of 60 feet above grade, with the exception of a horseshoe-shaped area on the north side. The landfill was developed in 10-feet-high lifts that were capped with soil and/or a hog fuel (shredded wood waste) intermediate cover. The horseshoe originally housed the scale and administration facilities.

To maximize revenues, the new landfill owner, who purchased the property in 1998, relocated the scale and offices onto an adjacent property north of the railway tracks and began to fill in the horseshoe. The bottom of the horseshoe first was covered with a 10-foot to 15-foot thick lift of inert concrete and blacktop demolition material from the 1986 World's Fair Expo site.

During the next 10 months, the landfill received a steady stream of demolition waste, including crushed dimensional lumber, tar roofing shingles, plastic and metal. Because materials were pushed into place with a bulldozer, the waste was loosely deposited in a single 50-foot deep layer throughout the entire horseshoe without proper compaction or soil fire breaks - contrary to operating permit requirements.

After issuing several non-compliance citations to the landfill, the British Columbia Ministry of Environment, Lands and Parks (MoELP) ordered the landfill to close on Nov. 9, 1999. But by that time, more than 250,000 cubic yards of waste already had been deposited in the horseshoe.

Anyone Smell Smoke? Ironically, steam and smoke had been emerging from the site for several weeks before the closing, but no one realized the landfill was on fire until flames broke through the surface on Monday, Nov. 8 around midnight, when the landfill owner placed a 911 emergency call. The Delta Fire Department responded with several pumper trucks that brought the surface fire under control during the next 24 hours. Managers thought the problem had been solved.

However, on Wednesday, Nov. 11, when a 50-yard by 100-yard sinkhole fell approximately 10 feet on the crest of the horseshoe and flames erupted on the steep face, the Delta Fire Chief realized that the fire was much more complicated than he first believed.

Concerned that the fire would spread, Delta Shake and Shingle operators began excavating 20-foot deep trenches around the burning areas, which they completed on Sunday, Nov. 14. But it quickly became apparent that these trenches would not be effective in stopping the fire because they penetrated less than one half of the fill thickness.

Seeing it was time to bring in a landfill fire specialist, the owners hired North Vancouver-based Sperling Hansen Associates (SHA) on Nov. 12. SHA's plan involved establishing perimeter fire guards down to solid soil around the horseshoe, excavating and extinguishing all burning material from the horseshoe, and conducting thorough geotechnical monitoring to ensure that surrounding utilities would not be damaged by the firefighters' efforts. A previous slope failure at the landfill had displaced the gas pipeline by more than 10 feet and had resulted in several million dollars in damages.

Sound the Alarm Over the next few days, the fire gained intensity. Fearing a serious environmental emergency, the British Columbia Fire Commissioner on Nov. 25, ordered the landfill to extinguish its fire following SHA's plan. However, because of the large anticipated cost of extinguishing the fire, the company ignored the order and eventually went into receivership.

By this time, smoke from the plume was starting to pose a health hazard to adjacent businesses. A thick haze began to choke much of the Delta area. Additionally, the potential spread of fire into the main landfill posed a serious threat to the British Columbia gas pipeline. Leachate from the firefight also began to pool, and was starting to affect the environment and threaten groundwater resources.

Consequently, the British Columbia Fire Commissioner determined that the fire was posing a serious threat to life and property and ordered the Delta Fire Department to extinguish the landfill fire according to SHA's plan on Nov. 27, 1999. To alleviate the landfill owner's cost concerns, the British Columbia Provincial Emergency Program (PEP) committed to help fund the effort.

However, some of the adjacent private property owners were less than cooperative. So to secure access, the Corporation of Delta's mayor declared a local state of emergency.

By Nov. 27, much of the 250,000-cubic-yard horseshoe was in flames, and a thick plume of smoke was rising into the skies.

Forming the Fire Safety Plan To extinguish the blaze, firefighters knew they had to eliminate one of three ingredients: the fuel supply, oxygen or the high-temperature ignition source. SHA considered six methods, including:

- Accelerating high-temperature combustion;

- Capping the landfill burn area with soil;

- Capping the landfill burn area with a geomembrane;

- Flooding the burn area with water from the nearby Fraser River;

- Injecting an inert gas such as CO2 to displace oxygen; and

- Excavating the burning material and then extinguishing it with foam.

The only feasible solution that seemed apparent to the SHA team was to excavate the burning material then transport it to an area where it could be soaked with water and fully extinguished. Specialists from Key Safety in Red Dear, Alberta, which were retained by the Delta fire chief confirmed the strategy.