Viewpoint – Exploring waste options

Northland Regional Council, and Kaipara, Whangarei and Far North District Councils have committed to investigate the feasibility of introducing waste to energy (WtE) for dealing with our solid waste streams. It is not possible to have this discussion without examining the comparative emissions from a landfill such as proposed at the headwaters of the Hoteo, which discharges to our unique Kaipara Harbour.
In terms of landfill emission to air, soil, and water, you cannot readily manage what you cannot measure. It is a committal to hundreds of years of discharge to our environment. There is no ‘off’ switch on a landfill.

The 2022 NZ Ministry for the Environment – New Zealand Dioxin Inventory lists landfill and their associated fires as contributing more than 55 per cent of our country’s yearly dioxin emissions. These landfill emissions have steadily increased since 2012.

WtE plants require continuous emission monitoring systems to ensure they are optimally operating. Comparing earlier WtE versions to modern operations is like comparing a Tiger Moth to a 747. Since the introduction of maximum available control technology (MACT) in 1987 dioxin levels internationally have fallen by 99.9%. In France, over the same period emissions fell from 435 TEQ to just 1.2g TEQ. By comparison, residential wood combustion (household fireplace) annually produces 320g TEQ compared to Frances 100 WTE plants producing just 1.2g TEQ.

Records show that more than 800 WtE plants operate in 40 countries and currently treat around 261 million tonnes annually. Our Australian counterparts are constructing WtE facilities. The energy recovered from modern WtE plants has the potential to power thousands of homes by providing electrical energy. Unlike landfill, WtE plants does not emit the powerful greenhouse gas methane and has the capability to capture food grade CO2.The recovery of ferrous and nonferrous metals, and the use of bottom ash and plasma treated fly ash suitable for roading and industrial use, is an additional economic benefit.

In an integrated approach, WtE complements recycling programmes. Wales has the highest recycling rates in the world at 67% (NZ is 28%) yet still has four WtE plants. In 1995, New Zealand embraced the ethos of zero waste. Since that time, as a nation, we have dumped well over 200 million tonnes of resource into landfills. Our solid waste production has steadily increased despite heroic efforts by many councils and organisations to reduce the tonnages. As evidenced in other countries, New Zealand could improve our efforts by engaging in an integrated waste management system, which after maximising our recycling efforts secures benefits from the remaining waste via WtE.

I look forward to a forthright discussion based on up-to-date evaluation of the economic, socio and environmental benefits of modern WtE technology now embraced in so many of our trading nations.
Please note: The views expressed in this column are my own and do not necessarily represent a consensus position of Kaipara District Council.