World-first waste innovation offers wider business potential
13 November 2012
Chief Executive Peter Guerin's 'Council Talk' column in today's Daily Post.
Rotorua District Council and Scion have embarked on an innovative joint venture project which has significant future business potential. Evolving from the ‘Waste 2 Gold’ programme, the newly developed process for transforming biosolids from the waste water treatment plant into useable products has the registered trade name of TERAX™.
Organic wastes currently make up about 65% of all waste disposed of at the landfill. However those wastes emit greenhouse gases and produce leachates, both of which are harmful to the environment. It makes management of organic material an expensive business for councils, with a number of risks.
Rotorua is already something of a leader in organic waste management. We were the first council in the country to construct a composting facility for sewerage derived biosolids some 20 years ago.
While this has worked well, in more rent years marketing of the product has proved difficult because of perceptions around risk of contamination of food products and European standards. Our composting facility now only processes greenwaste into 100% ‘biogrow certified’ compost suitable for commercial horticultural use.
To deal with remaining organic wastes, in particular biosolids, Council has partnered with Scion which has developed the leading-edge technology now known as TERAX™. This is a combination of biological and thermochemical processes that break down organic wastes into separate carbon and nutrient fractions. These can then be reused for a variety of downstream uses. In other words it is taking a problematic waste product and converting it into useful products.
This process is not just a New Zealand first, but a world first. We are now progressing to the detailed design phase of a demonstration plant capable of processing all of Rotorua’s biosolids – more than 8000 cubic metres a year. Not having to dispose of these wastes on land will eliminate the environmental risk and offer a more culturally acceptable option.
However there are also substantial economic benefits for Rotorua ratepayers as we expect to be able to reduce biosolids disposal costs by around $700,000 a year.
The council manages other organic wastes via the sanitary landfill. Now that the research phase on biosolids is nearing completion, attention will turn to using the new TERAX™ technology for the wider organic waste stream. RDC’s pilot plant at the city’s wastewater treatment plant will be used by Scion scientists and engineers to further develop the process for this mixed waste stream.
Eventually it is hoped that an additional full scale TERAX™ plant can be constructed, possibly at the landfill. Mining of the landfill for processing is even a realistic possibility.
Both RDC and Scion recognise the potential for taking this technology beyond just Rotorua’s needs and into the other industry, such as wood processing where large quantities of organic wastes are produced.
In the meantime the project is firmly focused on managing RDC’s wastes. Construction of a TERAX™ demonstration plant will be the key to realising the potential for a sustainable and cost effective method for management of Rotorua’s organic waste.
Peter Guerin
RDC Chief Executive