Kate Valley Landfill is the most comprehensively engineered land disposal facility within the South Island.The total site is 1,000 hectares, of which 37 hectares will be used in landfilling operation.Around 410 hectares of the site, in the lower Kate Valley, has been set aside in a protected conservation covenant for native forest restoration and wetland creation, known as Tiromoana Bush.
All features of the Kate Valley Landfill design and operation meet international best standards.This includes a ‘Liner System’ that contains leachate, a ‘Leachate Management System’ that pumps all collected leachate into storage tanks ready for treatment, a ‘Gas Management System’ which ensures compliance with air discharge consents and which will eventually be used to power a gas to energy system (when gas volumes increase), and finally a ‘Surface Water Management’ system which separates storm water from water that has contacted refuse.
As part of the landfill’s construction, a water supply dam was constructed around one kilometre downstream in Kate Valley. It impounds up to 50,000 cubic metres of stormwater runoff in a lake up to 500m long.This water is used to assist with construction of future cells, and for dust control.
The plant and operational equipment used at Kate Valley Landfill is amongst the most modern and technologically advanced in New Zealand. The landfill uses a new generation Caterpillar 836H Compactor which is used to compact waste as densely as possible, and the fleet of truck and trailer units used by CWS to haul waste from transfer stations to the landfill incorporates a full range of safety features, including Euro III Exhaust Emissions Standard, currently the most stringent emissions standard in the world.
Transwaste’s presence on the site is for the estimated 35 years design lifetime, followed by a minimum of 30 years of aftercare. Aftercare involves ongoing management and monitoring of the site until waste decomposition processes have finished, at which point end use will be for conservation and recreation.