Going Circular
2023 AWARD WINNER
Sponsored by ecostore
Watercare is making fertiliser from a resource it has learnt to recover from wastewater treatment. It also plans to produce other soil products using resources extracted during the treatment process.
In 2021 Watercare started trials to extract and purify struvite crystal from wastewater at its Mangere treatment plant in Auckland.
Struvite crystal is used to make fertiliser and feels like dry beach sand. There is a global demand for struvite fertiliser as it is long-lasting, slow release and does not cause leaf or root burn. Watercare's product, branded as Emerge Fertiliser, is high in phosphorous and pathogen-free.
Until now, Aotearoa New Zealand has sourced non-renewable phosphorous for fertiliser from overseas, with a significant carbon footprint.
Watercare says Emerge Fertiliser offers a local, renewable and high-value alternative. It has been tested on pasture and turf systems and is being used by farmers. Over the past year 150 tonnes has been sold. Watercare expects to produce 300 tonnes in 2024 and up to 3,000 tonnes per year in the future. It is about to enter the retail market through a nationwide chain of home improvement stores. It is also in negotiations with four fertiliser companies and has secured its first export order to Australia.
Watercare is developing other soil products including a garden potting mix using biosolids from wastewater. Over the next decade it aims to create a market for all the biosolids it produces. It says this will divert about 150,000 tonnes of biosolids from landfill every year. That's about the same as 20 truck and trailer loads per day. Landfill costs up to $200 per tonne. Emerge Fertiliser sells for $550 per tonne, proving that waste can be a valuable resource.
The judges said: "Emerge Fertiliser is a phosphorus-rich fertiliser that also includes nitrogen. It demonstrates innovative, bio-circular thinking from Watercare, a large scale organisation that is turning organic waste that would have gone to landfill into a high-value, renewable product. Emerge Fertiliser is locally-sourced from renewable sources. It avoids carbon from importing phosphorus and waste to landfill.
"We are delighted to celebrate transformative, circular and strategic thinking by an organisation acting as kaitiaki of valuable resources."