Frequently
Asked Questions
Why does Canterbury need another landfill?
It is no secret that Canterbury has a serious problem with respect to the management of low-level contaminated soils.
Canterbury historically had over 40 landfills scattered across the region. In 2005 it was decided these fill sites would be closed and Kate Valley, a class 1 landfill, would be created to accommodate all waste for the region.
The Canterbury earthquakes have had a large impact on our region’s waste streams – something that no one foresaw when the decision to establish Kate Valley was made.
Construction and demolition (C&D) waste – namely inert concrete and rubble – has been an issue since the earthquakes, leading CCC & ECAN to reopen Burwood Landfill shortly after the quakes. Burwood Landfill is used for low level contaminated soil to rehabilitate the landfill for an end recreational land use.
Contaminated soil disposal is a significant problem for the Canterbury region. In Christchurch, with Burwood Landfill due to close permanently due to no longer needing soils as its rehabilitation as this is complete. It is now only accepting contaminated soils for another two years due to there being no other managed fill near Christchurch, and the higher costs associated with the soils being taken to Kate Valley.
Protranz’s application is aimed at ensuring the right waste goes to the right managed fill and not putting class 3 waste in a class 1 Landfill.
Is there a risk to the local waterways and drinking water?
There is some concern about the impact of the managed fill on drinking and ground water.
Experts have found a class 3 managed fill is low risk. To provide an additional layer of reassurance, the proposal is to cover the base and sides of the managed fill with an engineered liner.
This liner is designed to provide an impermeable barrier to prevent any leakage into the environment. This is not a legal requirement for a class 3 managed fill, however it’s an additional measure Protranz want to take.
The proposed liner is designed and used for a higher-risk class 1 landfill, which gives the highest possible protection to surrounding water and soil.
Further to this, there will be additional stormwater management systems and erosion and sediment and controls in place in accordance with best practice.
Ongoing water quality and ecosystem monitoring will be carried out.
What about leachate?
Leachate is not something that is generated by managed fill material itself but is limited to rainwater directly coming into contact with the material, or infiltrating into the material. Leachate will be collected and contained in a leachate pond onsite. This leachate will be removed from the site to a suitable waste treatment facility. Post closure with the full capping system the leachate volumes generated will reduce and over time the low strength of the managed fill leachate will continue to reduce.
Will there be an odour?
No. The managed fill site will not receive green or domestic waste, there will be no odour from the site.
Will it attract vermin, birds and flies?
No. Managed fill materials are inert and do not provide a food source for rodents.
What is contaminated soil?
Soil may be contaminated if it has previously impacted by a current or historic land use.
According to Environment Canterbury, sites that may have been home to industries that traditionally used hazardous chemicals include ones that were previously market gardens, orchards, sheep dips, landfill sites, timber treatment areas, dry cleaners or service stations. Sometimes the chemicals used on these sites have ended up in the soil and can affect the land for many years after the activity has ended.
Residential areas can have contaminated soils due to asbestos containing materials in buildings being released during their repair or demolition. Lead paint stripping and sanding on older weatherboard homes for instance has resulted in contamination of surrounding soils. Zinc leaching from galvanised iron roofing can impact on soil quality.
What are benefits of the proposed project?
This project will also provide a $100m saving to the community, government agencies, local government, private developers and homeowners, by reducing the disposal costs associated with low-level contaminated soils, which continues to be a major problem for developments.
In addition, it will create nine new jobs for locals – part of Protranz’s commitment to supporting the community.
What about the risks of earthquakes?
Concerns have been raised about the impact of seismic activity on the safety of the managed fill.
Key ways Protranz will ensure the managed fill remain secure and functional even during significant seismic events include:
- Flexible Liner: The proposed liner has been designed to prevent tearing and maintain containment during seismic activity. As a liner designed for a higher-risk class 1 landfill, it will give the highest possible protection to surrounding water and soil if there is an earthquake.
- Reinforced Slopes: The slopes of the landfill will be reinforced to prevent landslides and maintain structural stability.
- Drainage Systems: Effective leachate collection systems will be installed to manage the movement of liquids, reducing pressure on the landfill structure.
