Capping a Landfill: Gel Rates on 150 mm of Stony Cover Soil

Closing a 4 hectare cell means putting a cap on it, and a cap is a hostile place to grow anything. The specification called for 150 mm of cover soil over the geomembrane, a stony, compacted material with 30 percent gravel and a pH of 8.4, seeded with a mix of fescue and legume. The first attempt in …