Hampton Downs Landfill - Stage 3B, North Waikato
Welded 1.5mm double textured HDPE and geocomposite clay liner (GCL)
Hampton Downs Landfill is New Zealand's largest and most advanced landfill servicing the Auckland, Waikato and Coromandel areas. Situated on 360 hectares of farmland and developed in stages, the landfill will eventually cover an area of 87 hectares.
I.S. Dam Lining returned to complete the Stage 3B extension, contracted by owner/operators EnviroWaste to deploy 21,500m2 of HDPE and GCL.
Preventing landfill liquid from entering the soil and groundwater supply (leachate management) is a key component of modern landfill management. EnviroWaste use sophisticated monitoring techniques to ensure effects on the surrounding environment are minimised.
I.S. Dam Lining expertise was called upon to deploy an un-penetrable GCL and HDPE leachate drainage layer to contain liquid run-off that is then pumped into storage tanks for processing and discharge.
The synthetic liners (HDPE and GCL) were laid over a compacted soil base, followed by a protection layer consisting of 200mm of compacted clay. This was topped with 300mm of gravel forming a leachate drainage layer and provides a robust and secure leachate management solution.
Favourable weather conditions saw this large scale project being completed ahead of schedule, with deployment and quality assurance testing achieved in 10 days.