Bing found the following results
Landfill - Wikipedia
Basic Information about Landfills | US EPA
Landfills - National Geographic Society
How Landfills Work | HowStuffWorks
Cutting Landfill Methane To Fight Climate Change : NPR
Basic Information about Landfills | Landfills | US EPA
EPA underestimates methane emissions from landfills, urban areas
Municipal Solid Waste Landfills | US EPA
EPA Unveils Plan to Reduce Dangerous Pollution from Landfills
Landfills | US EPA