The waste from the landfill will be fully contained by a purpose designed and constructed landfill lining system. The lining system protects the surrounding environment from contamination from leachate as well as controls the entrance of groundwater.
The leachate is collected in pipes, then extracted from the landfill and treated. No leachate will be discharged into streams.
The selected lining system is physically designed to provide containment for hundreds of years after the landfill stops receiving waste, by which time leachate is not being created, and no longer poses a risk to the environment.
Best practice stormwater management techniques will be designed and constructed for the landfill to mitigate potential environmental effects on the surrounding environment.
Any clean stormwater upstream of the landfill will be diverted around the waste.
Downstream of the landfill there will be a series of stormwater management ponds (dams) and wetlands. These will be designed to remove sediment before it is filtered by wetlands and released to streams onsite and eventually into the Hoteo River (approximately 3km away from the end of the landfill).
We will constantly monitor the quality and volumes of stormwater and will be required to report regularly to Auckland Council.
The area covered by the proposed landfill footprint will be less than 0.25% of the catchment for the Hoteo River.
We will be replacing any pine trees that need to be harvested for the proposed landfill as well as planting additional trees. An area of 100ha has been set aside for off-set re-planting of pine trees.
We will also protect significant areas of indigenous vegetation and fauna with a covenant to protect them into the future. In addition, riparian planting and fencing will be undertaken to stop stock entering the Hoteo River where we have a boundary on the river.
Please read more on our guide to groundwater and potential leachate migration here