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The
Malojloj Hardfill Burning
Mulch Issue
The
Malojloj Hardfill Task Force is interested in receiving
comments
from professionals experienced in landfill closure
design, combating underground fires, or organic debris
management. This is not a Request for Proposals (RFP).
Background
The Malojloj Hardfill is an approximately 400 feet wide by 500 feet long former coral pit located on the eastside of Guam's shoreline. The depth of the coral (limestone) pit is not known, but is suspected to be approximately 100 - 200 feet deep. After the Government of Guam ceased excavation of limestone from this location, it was decided to use the depression as a Hardfill in the early 1990s. In addition to construction debris, metallic debris inclusive of automobiles, refrigerators, air conditioners, sheet metal, etc. has been disposed off in the Hardfill over the years.
In December of 1997, Typhoon Paka hit Guam. After collecting thousands of cubic yards of vegetative debris from around the island, FEMA suggested shredding this waste to extend the useful life of the Hardfill. Mulching and shredding of this vegetative debris as well as wood pallets and other typhoon debris was completed in March/April of 1998. It is estimated that an approximately 20 feet deep layer of mulch is present within the Hardfill (some areas are as deep as 80 - 100 feet, others only 6 feet).
In October of 1998, a subsurface fire erupted at the Hardfill. The area that was burning was excavated and doused with water to extinguish the fire and mitigate the heavy smoke that was impacting residential dwellings approximately 50 feet from the Hardfill. After successfully extinguishing the smoldering mulch, the material was placed back into the Hardfill.
Last month, residents near the Hardfill noticed that steam and smoke was escaping from the area again. Upon inspection of the mulched material, it was noted that two (2) depressions had formed near the middle of the Hardfill and that heat and smoke was escaping through cracks and fissures that had formed on the surface, as well as along the eastern side wall of the coral pit. This venting has currently been mitigated by placing clay fill material on top of the mulch in the areas of concern, and trenching along the wall of the coral pit and filling this trench with clay.
Long-term Solutions
The Government of Guam recognizes that although the capping of vents has been successful, it does not address a long-term solution to the problem at the Hardfill. Based on air monitoring data collected and observations at the site, it is apparent that the cause of the subsurface fires is the decomposition and fermentation of the vegetative debris. This heat generating process is expected to continue building up combustible gasses and noxious fumes that affect the surrounding residents.
The Government is presently evaluating potential long-term solutions and is evaluating the following:
Any successful long-term solution will need to take into account minimizing the impact to the surrounding residents, the time needed to implement the solution, and short- and long-term operating costs.
LINKS:
Mulch fires are actually quite common. Robert Kelley of the Governor's Office found the following articles on the Internet, which describe how other communities throughout the U.S. have encountered and dealt with this problem:
- The Record reports on a mulch fire 'nightmare' in Pequannock, NJ in September 1997.
- The Fayetteville, N.C. Observer discusses a mulch fire that occurred in July, 1998.
- The Beaufort Gazette reports on mulch fires at a tree care company on Hilton Head island in February 1999.
- The Herald Mail reports on a mulch field on fire in Shepherdstown, West Virginia in March 1999.
- Channel 3000 News website reports on a compost heap fire in Sharon, Wisconsin in March 1999.
- Finally, the Tribune in Florida reports on a mulch fire that raised health concerns at a recycling company in May 1999.
