Inexpensive technology to treat sewage will be introduced at Kaka Point and it could be introduced to other small Clutha communities that need upgrades most cannot afford.
A new system, developed by Wyndham-based company Biofiltro, has been cautiously approved by the Clutha District Council, whose staff admit there are some uncertainties with the system but say the potential benefits outweigh any risks.
The council has approved spending up to $264,000 on the system, subject to signing a satisfactory contract which will include performance guarantees that Biofiltro will be expected to meet during and after construction.
Biofiltro has adapted sewage treatment methods from Chile.
A bioactive sawdust bed, supported by a rock drainage layer, digests the sewage, using ultraviolet to help disinfect the treated sewage.
Council district assets manager Jules Witt said it could halve the annual costs of the cheapest options previously considered for towns like Benhar and Tokoiti which are facing expensive upgrades neither community can afford.
The Kaka Point model was estimated to cost Kaka Point ratepayers an extra $160 a year compared to other options that ranged from $280 to $620.
In a report to council last week, projects engineer Peter Ross said there was little, if any, monitoring data of the Biofiltro operation, making it hard for council to get a clear picture of its success.
Small sample results from New Zealand were "comforting".
While the evidence provided by Biofiltro "does not definitely give comfort" it will met consent requirements, Mr Ross said it was clearly possible.
"This less-than-perfect result needs to be weighed against the substantial cost-savings at Kaka Point and potential savings elsewhere should the system fulfil its promise."
It could be used at up to seven other sites around Clutha.
