The Kaikoura community will weigh in on what should happen to the town's 1500-tonne pile of treated sewage as researchers prepare residents to make a recommendation to the Kaikoura District Council.

Scientists from Crown Research Institute Scion explained the environmental impacts of the bio-waste's different reuse options to community group leaders at a hui held at the Takahanga Marae last Thursday.

Information on the possible impacts came from a life cycle assessment that was funded by the council and the Sustainable Initiatives Fund Trust.

Stakeholders were asked to prioritise the potential impacts according to the needs of the Kaikoura district.

Scion worked with a group of researchers from the bio-wastes programme, which included Te Runanga o Kaikoura, to advise the community on what to do with the sewage.

The bio-solids were dredged from the bottom of oxidation ponds at the Kaikoura Sewage Wastewater Treatment Plant on Old Beach Rd.

About 1500 tonnes was stockpiled in a natural hollow at the site in 2006.

The pile had weathered, become more soil-like, and could be moved and reused.

The Kaikoura District Council's resource consent allowed the waste to remain at the location until 2016.

Scion resource economist Richard Yao asked residents and others to value the treated sewage by trailerload to gain a better understanding of its retail value.

The total value could then be calculated against the costs of preparing the waste as fertiliser.

"We know the value price of a trailerload of regular compost, but we don't know the value of bio- solids compost," Mr Yao said.

The financial costs involved could be assessed with the possible environmental benefits, he said.

Residents decided the quality of land and water usage were the most important environmental factors in the assessment.

Scion researcher Alan Leckie said it was important for residents to share their opinions on how the treated sewage should be prepared for reuse and what option they wanted the council to use.

"`If we have this knowledge we can help the community because what we do now may well assist the community and council for what we do in 15 to 20 years time when the ponds require the next desludging. The cheapest option is not to do anything with it and ask the council to extend the resource consent, but the environmental impact could be very high," Mr Leckie said.

Previously the community had decided to reuse the bio-solids as fertiliser in some manner, possibly because of its low nitrogen level.

The options to turn the bio-waste to fertiliser were using the bio-solids in open-air composting, adding worms to create extra moisture known as vermi-composting, applying it to a forest or farm and mixing it with a form of charcoal called bio-char.

Bio solids were typically sent to landfills because of the fear of pathogens and contaminants from everyone's sewage. However, bio- solids were commonly carbon-rich and tended to contain valuable nutrients.

About 50 representatives from the Kaikoura community would be asked to attend a fourth bio-wastes hui at the Takahanga Marae with the council on March 4.The results would also be presented at the New Zealand Land Treatment Collective and the Life Cycle Association of New Zealand conferences in 2012.