Sodium bentonite swells up to 18 times its dry size when it becomes wet. Expanded bentonite forms an impermeable gel seal which makes an excellent landfill liner. Sodium bentonite is all natural and is more cost efficient than synthetic liners.
Apply a layer of bentonite liner (Granular Seal, Bentonite Powder, Pond Seal) of a thickness of up to 24 inches before the deposition process. When the site is filled, cap the waste fill with another layer of bentonite liner of six-inches to prevent water from seeping into the waste fill. Finally, the whole area is covered with at least two feet of soil in order to encourage ecological reestablishment.