PROJECT OUTLINE

Lamby Way landfill site is an integral part of the waste disposal infrastructure of the Cardiff area. The client, Cardiff Council, appointed Walters to undertake a significant capping project at the site in order to open up a portion of the land for final landscaping.

Capping is a cost-effective way of remediating an existing landfill, and was selected as the desired remediation process in this instance. As part of the project the Council specifically requested the installation of a surface water drainage system and set ecological constraints on the scope of works.

PROJECT DELIVERY

Walters undertook the works to cap the 40,000m² eastern flank of the site (cells 1 and 2), including preparation in terms of site clearance, local reptile relocation and disposal of Japanese knotweed.

Constructing a barrier and drainage layer ensures the land above the landfill is suitable for reuse, with the landfill below the line remaining dry – assisting in leachate reduction. Around 12,000m3 of regulating soil layer was introduced (with full soil analysis) and a rigorously-tested geo-textile layer (over a 1mm HDPE liner) and geo-composite drainage layer was installed, with close liaison with the client”s CQA team at all stages.

A further restoration soil layer was placed along with surface water drains, and the scope of the project was extended to include the capping of an additional 5,000m2 and the secure decommissioning of 10 live leachate wells.