Alternative options for disposal of treated Mangawhai wastewater are to be canvassed before Kaipara District Council decides whether to extend the present on-farm irrigation system.
The Council wants to see if there are more cost-effective options for the volumes expected in the future.
When the Mangawhai Community Wastewater Scheme was designed it was decided that disposal should be land-based and outside the Mangawhai Harbour catchment.
As a result the treated water is piped 11 kilometres to a farm, purchased for the purpose, on Brown Road at Hakaru. It is stored in a large dam and during summer and autumn is irrigated onto 25 hectares on the property where a total of 65 hectares are eventually intended for this purpose.
However, KDC General Manager Operations John Burt says the current 25 hectare field is sufficient only for present volumes of wastewater in an average year and that, even if current discussions with Northland Regional Council concerning changes to the Environment Management Plan and Resource Consent allow more to be sprayed on the current area, this amount will be small.
“Therefore Council needs to either extend the irrigation system or identify alternative options for disposing of the treated wastewater.”
Council has budgeted $445,000 in its Long Term Plan 2012/2022 for a 20 hectare extension to the irrigation system and is currently considering developing 6 hectares.
Mr Burt says the community would expect the Council to consider all available options and to identify the most cost-effective method before proceeding.
Council’s Commissioners decided on Monday to seek Expressions of Interest from suitably qualified contractors to evaluate the alternative disposal options that might be available.