methane

"Without vents, methane and other gases remain trapped at the bottom, further multiplying the fragility of the loosely held structure."

In a 25-hour period, neighbourhood researchers found 13 outdoor methane leaks at concentrations exceeding the lower explosive limit.

In that time, CalRecycle inspectors also identified violations for elevated levels of flammable methane, improper signage and failure to conduct sufficient truck inspections to ensure hazardous wastes aren’t disposed at the site.

And although landfill operators routinely monitor for potentially dangerous gases, such as methane or sulfur dioxide, they typically don’t have instruments that would detect toxic contaminants in wildfire ash, like lead or asbestos.

These tiny particles have historically masked some of the long-term warming from greenhouse gases like carbon dioxide and methane by helping to form bright clouds and reflecting some of the Sun's energy back into space.