Assessing the Effectiveness of Landfill Remediation and Restoration at a Closed Landfill Site: Nantygwyddon Landfill Site, South Wales

This paper concerns the first stages of the final remediation of a waste disposal site located in the Rhondda Fawr, South Wales. Nantygwyddon Landfill Site closed in 2002 and remained temporarily covered until the summer of 2005 when a fully engineered landfill cap was installed. Prior to installation of the cap a detailed monitoring programme indicated the presence of low level diffuse groundwater and surface water pollution from landfill leachate and contaminated surface water runoff. The landfill gas produced by the site contains elevated levels of hydrogen sulphide as a result of industrial waste being deposited in the waste mass. A soil vapour survey indicates that whilst temporarily capped the site was not fully sealed and landfill gas emissions were detected through the soil barrier. Long term monitoring of the groundwater and leachate systems will assess the changes occurring to the site after the installation of the landfill cap.