Sonoma County Landfill
Soil Bentonite Cutoff Wall And Groundwater Collection Trench
Sonoma, California

Geo-Con constructed a slurry wall and a collection trench at the Sonoma Landfill in Sonoma, California. This site included a closed landfill and an active recycle center and transfer station which required continuous access. The project consisted of constructing a soil-bentonite cutoff wall and a gravel collection trench. The cutoff wall with a maximum depth of forty-four feet and a maximum permeability of 4.5x10^-8cm/sec. provides isolation of groundwater from seeping into the existing municipal landfill. The groundwater collection trench provides diversion and collection of runoff water from overtopping the cutoff wall and seeping into the landfill. A clay cap was placed and compacted over the completed slurry wall and the completed collection trench. The project was completed in two months with restricted site access and without delays of the active recycling center and transfer station operations.

• Start: 9/20/99
• Completion: 11/12/99