Project Summary
Construction of 20,000m2 new waste cell. The lining of the new cell with Type A liner and lining of the new cell with specialist HDPE liner.
Project Description
Construction of 20,000m2 new waste cell. The lining of the new cell with Type A liner and lining of a new cell with specialist HDPE liner.
The project involved the construction of new cells, including lining and leachate collection system and leachate holding tanks. The cells area is 20,000m2. The excavation to formation level was carried out and the material that was excavated was used to create embankment.
Project Delivery
Once excavated to formation level a Type A Lining was installed in this case. A type A liner involves the installation of 1.0m of impermeable clay over the area of the new cell (20,000m3). This layer is spread out in 250mm layers using a dozer equipped with GPS to make sure that the levels are correct and then compacted. Testing was carried out on this layer once it was in place to make sure that it conformed to the standards set out in the contract. Once the liner was in place then the geotextile carpet (20,000m2) was laid out over the cells. (this is a protection layer between the liner from the leachate.).
Approximately 7,000m3 of leachate stone was spread over the contract. the depth of leachate stone used was 500mm over the complete landfill area.
New surface water swale drains were installed around the cell and this connected to the existing drainage system.
- There were the supply and installation of new vertical gas wells in the newly constructed capped layer.
- The gas that was trapped in the first geotextile layer is collected via these vertical gas wells. Transport pipelines (HDPE welded pipe) were constructed to a manifold and leachate knockout pot which in turn was connected to the existing gas flare.
- A new leachate pipeline and holding tank were constructed for the new cells. 145m of 90mm internal diameter (HDPE with fusion jointed pipes), 890m of 200mm (HDPE), 120m of 110mm (HDPE), and 190m of 560mm (HDPE) leachate collection pipeline was installed. A Leachate lagoon was constructed along with associated pipework and M&E plant.
- A new Surface Water Management system was installed on the site and this involved laying of 200m of 225mm dia surface water (Concrete pipes class H) pipeline and 20m of 225mm dia surface water (HDPE with butt fusion joints) pipeline. Pipelaying of surface water pipeline – 22 m of the 500mm concrete flexible jointed socket and spigot pipe, Pipelaying of water main Construction 700 m of 100mm uPVC complete with fittings, valves, and hydrants.
- Fencing – 500m of 2.5m high timber post and chainlink and barbed wire fence with gates.
450m of 2-way ducting of 160mm uPVC class B duct was installed - As part of the contract and extension to the washroom facilities was carried out. This involved an extension to an existing building, plumbing, new sanitary ware, tiling, plastering and painting
Coffey Construction was the principal contractor on the site and was the PSCS for the contract. All the works on site were carried out by Coffey Construction Ltd.
