Unless mistaken this refers to Augean's Thornhaugh sites. Liners being introduced there suggest that Augean wish to deposit waste of a more hazardous kind. I thought that liners were mandatory for landfill sites above limestone aquifers, common around here. Was told of a former quarry above our common aquifer and used for landfill before liners were demanded. This resulted in the water table North of Peterborough being polluted and dire effects upon drinking water supplies. Some time ago but it is a reminder of what can go wrong. Hence the introduction of liners that hopefully will outlast the hazardous elements within the waste material.