OPINION: Conservation Comment - reducing Whanganui’s organic landfill waste

Whanganui District Council waste advisor Stuart Hylton. Photo / Stuart Munro

It is estimated that the food waste sent to landfill from New Zealand households adds up to more than 100,000 tonnes per year.

The problem with this is that the decomposition process produces methane, a potent greenhouse gas. This, including commercial waste, contributes 4 per cent of New Zealand’s total emissions.

However, all this organic matter represents a resource that can instead be used to improve the environment, instead of polluting it. Rather than being converted into methane, the carbon contained in organic matter can be returned to the soil, where it can be stored long-term, improving the soil at the same time.

There are various ways in which we can reduce the loss of carbon through pollution. We can all do our bit to reduce unnecessary waste. Firstly, we can avoid having unused food that we need to dispose of, because it becomes spoiled or goes past its use-by date.

It is estimated that over a quarter of the food product purchased in the country ends up being wasted, the equivalent of $644 per household of edible food per year - nationally, this is about enough to feed a city the size of Wellington. Purchasing just the amount that is needed helps, and excess foods can be creatively made into delicious meals. Regularly check your fridge and pantry for leftover food products. Use-by dates are more a guideline than a requirement not to use the food after that date.

Waste paper and cardboard can be taken to the Resource Recovery Centre in Maria Place, next to the Fire Service complex, to be recycled. In a previous Conservation Comment, I discussed how you can conveniently and efficiently compost your own organic material. This is the gold standard for reducing organic waste, as you aren’t adding to transport emissions when you process the material at home.

As well as food scraps, you can add a similar amount of waste paper to the compost system, making it even more environmentally-friendly, by storing more carbon as well as creating a fabulous compost, which can be used to improve your soil. As an alternative, cardboard and paper can be laid on the ground under a mulch such as bark or chips. It will gradually break down, adding to the carbon sequestered in the soil. Remove any plastic tape from the cardboard first.

However, composting or mulching isn’t practical for all households or situations. In principle, the Whanganui District Council is planning a kerbside collection of organic material from mid-2024. As well as taking raw food materials, the service will collect cooked food, dairy, meat, and fish, as well as some compostable packaging.

EasyEarth is a Whanganui business that collects food waste and processes it to create compost, which can be added to gardens to improve fertility. The system uses an aerobic decomposition system, which avoids the creation of methane. EasyEarth provides a 10-litre bucket, and collects it each week for a fee. As a cheaper option, you can drop the filled container off on a bucket swap basis.

The Whanganui District Council’s waste advisor, Stuart Hylton, says Easy Earth has had support from the Council’s Waste Minimisation Fund to purchase machinery and set up their service. The Waste Minimisation Fund comes from a government levy placed on rubbish taken to landfill.

“Councils receive half of the levy from rubbish taken to the landfill and are required by law to spend it on waste minimisation initiatives,” Hylton says.