8,300 landfill fires per year in the U.S., underground ones burn for years

Firefighters, landfill operators, and nearby communities face an average of 8,300 landfill fires per year in the United States. Surface fires are manageable, but subsurface fires -- caused when biological decomposition heats buried waste to its autoignition point near methane pockets -- can burn underground for months or years and are nearly impossible to extinguish with conventional methods. The Chiquita Canyon Landfill in Castaic, California illustrates the severity: a subsurface fire ignited around May 2022 across 30 acres, and by February 2024 the EPA issued a unilateral administrative order declaring 'imminent and substantial endangerment to nearby communities.' Over 20,000 residents were exposed to hydrogen sulfide, carbon monoxide, and volatile organic compounds. The problem persists because landfill operators have no reliable early detection system for subsurface thermal events -- by the time elevated temperatures are detected at the surface, the underground fire may already be extensive. Excavating burning waste risks explosive methane release, so operators are often forced to simply wait, sometimes for years, while toxic emissions continue affecting surrounding communities.