Biosolids research continues

01:53, Nov 16 2011

The issue of biosolids and what to do with them is the subject of a research study currently being done in Kaikoura.

Biosolids are treated sewage sludge and every person produces about 27 kilogram of dry biosolids each year. In 2006 the treated biosolids were dredged from the bottom of the oxidation ponds at the Kaikoura sewage treatment plant and about 1500 tonnes stockpiled in a natural hollow at the site.

Now efforts are being made to help the community decide what to do with this material. A project being driven by a multi-disciplinary research team, which includes Te Runanga o Kaikoura, is under way to address the issue through community involvement and dialogue.

Historically, biosolids were sent to landfills because of the fear of pathogens and contaminants. However, biosolids are also carbon-rich and contain valuable nutrients, which could potentially be used for a range of land-based applications.

A collaborative group of researchers from the Biowastes Programme has been meeting with local iwi and other stakeholders, including the district council, to address the question of what to do with Kaikoura's biosolids, as they cannot remain stockpiled beyond 2016.

The government-funded project has been going for two years, and the programme team is made up of representatives from Crown Research Institutes (like Environmental Science and Research, Scion, and Landcare Research), universities (Lincoln University), research institutes (Cawthron Institute) and the Kaikoura community.


As time draws near on the council's current resource consent for the stockpiled biosolids, the question remains – where to from here?

With a big pile to dispose of, the group is exploring a number of options with the community. Through research and communication of the research findings to representatives of a broad spectrum of the community, the aim of the programme is to enable an informed decision to come from the community.

From a possible 19 options initially discussed, five have been highlighted from a hui held earlier this year. All are land-use based options. An economist is currently working out the costing and economic viability for these five options. It is possible that the biosolids could be processed so the material could be used, if that is recommended by the community.

Results of interviews with members of the community and scientific studies on the biosolids have been discussed with key stakeholders at two hui. By providing the research results, it is hoped an informed decision can be made for Kaikoura. Feedback, whether it be from an environmental, economic, cultural or social perspective, continues to be collated.

The group says the study and subsequent consultation offers a good opportunity to raise the profile of waste disposal and open up discussions and look at ways of modifying people's behaviour.

Te Runanga o Kaikoura representative, Raewyn Solomon, said becoming involved in the project was a huge wake-up call for her.

"It's quite scary really," she said. "When you look at what we are putting down our drains, it really makes you start to think about your own responsibilities ... This is our problem and we need to decide what to do about it."

A further hui, planned for Kaikoura at the beginning of March, will bring the community and council together with the knowledge of the research team to make recommendations on the future of the biosolids.

A second case study is also being conducted in the North Island, in Mokai, near Taupo.

Kaikoura Star