Links and Resources
This is an edited version of the website that the citizens’ assembly used during the process. All the videos that contain identifiable information has been removed, in accordance to the requirements of the UAHPEC.Environmental considerations
Q: With Climate change now being obvious, shouldn’t the 30 year plan include 100 years?
A: We don’t know what will happen in 100 years but when we plan for a thirty year horizon, we still expect our assets to last well beyond that (like our dams)
Q: Can we get some more background about the environmental impacts of desalination discharge? What studies/data do we have on local environmental impact and global environmental impact?
A: The environmental impacts are the return of the brine into the environment (which can have an impact on marine life) This is still being studied.
A: can have an impact on marine life) This is still being studied.
In the Arabian gulf, ecologists have noticed changes in species composition and shifting of spawning seasons near a desalination plant. The cumulative long-term effect on receiving water bodies and their biodiversity is unclear.
Q: Have RMA/NZ coastal policy laws/AEE been considered?
A: Whichever option(s) we go with, we will need to meet increasingly strict environmental standards (RMA).
Wastewater and environmental impacts
Q. What is the exact process of removing waste from wastewater and where do they go? Can we ensure that the waste from the recycled water is disposed of in an environmentally friendly way?
A: The stuff that is more than 3mm thick is captured in filters and trucked to landfill.
A: The residual sludge is dried and currently used as beneficially as possible, with increasing benefits as technology allows.
Q: What are the environmental effects of by-products on the Manukau harbour? Are there any studies of environmental changes occurring in its vicinity?
A: Levels of some contaminants (e.g. copper, lead and zinc) were elevated in the Māngere Inlet, possibly as a result of wastewater discharge. The disturbance to ecosystems has lessened with improvements to wastewater treatment facility, according to a recent environmental monitoring report (https://www.knowledgeauckland.org.nz/media/2120/synthesis-state-of-the-environment-monitoring-manukau-harbour-final_web.pdf). Recycling water would further reduce impacts on the harbour as less treated water would be released.
Q: Relatively speaking, how much waste is produced by each option (recycling and desal), and what is the relative yield of drinkable water?
A: For wastewater recycling, the amount of solid waste is the same as it is now, it’s just the waste from our wastewater treatment. With recycling options, we would be using the water instead of putting it into the harbour after treatment.
A: With desalination, the waste is brine that must be discharged in the harbour. The yield of drinkable water from the amount treated is lower than with recycling.
Q: What happens to the waste products of the recycling options?
A: There is an opportunity to capture nutrients for re-use with recycled wastewater. It is likely that there will always be some waste product that will need to be put into the environment just as we do today with wastewater by-products.
Q: For the sludge by-products of option 3, how much is discharged to landfill compared to current wastewater treatment practice?
A: The amount of solid waste is the same – the water portion that is being purified and re-used
About Koi Tū
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