Contractors place an engineered cover, called geomembrane, over the balefill area at Pasco Sanitary Landfill.
New cover will further prevent oxygen from reaching the fire and will also help trap carbon dioxide, which will be injected underground as part of the plan to extinguish the underground fire.
PASCO, WA - Washington's Ecology Department is working with local emergency and fire officials to monitor and suppress an underground fire at the Pasco Sanitary Landfill.
Crews began investigating after a small section of the landfill, about 25 feet in diameter, sunk nearly two feet. Smoke was also observed coming from the cracks in the soil. Contractors used carbon monoxide detecting equipment to confirm combustion.
"There is no immediate threat to people living near the site, local businesses or site workers based on our current knowledge," said Mike Hibbler, Toxics Cleanup Program regional manager. "We immediately informed and are working closely with Pasco and Franklin County fire departments and Franklin County Emergency Management Division to monitor and suppress the fire."
Investigators are working to gather additional temperature information to more accurately define the area of the fire. Contractors are covering the site with soil to help smother and prevent oxygen from reaching the fire.
The fire is currently localized in a portion of the landfill that contains bailed municipal waste.
An adjacent section of the landfill containing drums of hazardous waste, known as Zone A, is currently being treated with technology that draws air through the soil to prevent pollution from reaching groundwater or building up in the soil.
The site is closed to the public and no trespassing signs are posted.