Customer:Cardiff Bay Development Corporation
Value: £3.5 million
Stage 1 consisted of the import of 420,000 tonnes of waste from the adjacent former landfill sites of Ely Fields and Ferry Road Retail Park.
A HDPE lined containment cell was constructed for the disposal of 30,000 tonnes of heavy contaminated materials, asbestos and a deep burial cell for disposal of 5,000 tonnes of Japanese Knotweed infested materials. A 200mm layer of cohesive material was then laid as a temporary capping.
Leachate drainage was then improved and a 1350mm diameter storm water sewer was installed, in tidal conditions, to connect the adjacent retail park to the River Ely. A new 500m culvert was created around the perimeter of the landfill cell.
Stage 2 consisted of the installation of 150mm diameter wells to recover gas for recycling. These were interconnected in HDPE pipework to the gas recovery system. Permanent, engineered 800mm thick capping was then installed in order to seal off the site.