How are landfills constructed?

Under the waste:

1. The existing sub grade is excavated to create a solid base for the waste.
2. The liners are installed.
3. Three foot layer of recompacted clay.
4. Sixty mil thick synthetic Plastic 2 liner.
5. Leachate collection system (either granular material or geocomposite). 
6. Protective layer (typically sand). 
7. Layer of select waste. 
8. *Daily cover which is a 6 inch dirt layer or a specifically designed tarp.

*Unless the facility is open 24 hours.

On top of the waste-the Final Cap

1. Six inches of daily cover.
2. One foot layer of intermediate cover soil.
3. Eighteen inches of re-compacted soil
4. Sixty mil thick synthetic Plastic 2 liner.
5. Two and a half feet of protective/vegetative soil and grass.