The repair bill for the flood-damaged Omakau wastewater treatment plant is yet to be finalised. However early estimates indicate it to be $110,000.
    Central Otago District Council water services manager Ian Evans said damage assessments revealed the site sustained less damage than initially anticipated despite tree debris pushing over security fencing and accumulating in and around the ponds.
    One side of the pond embankment sustained minor damage which required reinstatement to protect it from further damage but the pond liner — initially feared to have sustained significant damage — received minimal impact, only needing some relatively minor patch repairs.
    It appeared the liner protected the pond embankments from more significant damage, Mr Evans said.
    While damage occurred to mechanical and electrical components, the impact was reduced by quick action taken to turn off power at the site.
    The access track required reinstatement after the flood event.
    Since the flooding, debate had arisen online regarding the location of the treatment ponds and whether they should be relocated.
    Mr Evans said a business case was being prepared to consider alternative options for treatment of wastewater from both Omakau and Alexandra, exploring options for treatment and discharge to land instead of waterways.
    ‘‘This decision is being considered carefully, as potential alternatives range in the vicinity of $30 million to $50 million,’’ he said.
    Otago Regional Council (ORC) general manager regulatory and communications Richard Saunders said the discharge of contaminants into water was a concern and the situation was being ‘‘closely monitored’’ with staff making ‘‘multiple visits’’ to the site.
    ‘‘A full investigation into the incident will occur, but the immediate priority has been to allow CODC staff to focus their attention of remedial work to stop the discharge of the partially treated wastewater to the Manuherekia River.’’
    Any event that may result in a discharge to freshwater was a concern and ORC would continue to work with the district council to prevent this, Mr Saunders said.
    The district council had resource consent for the operation of the treatment ponds in their current location. However he was aware it was preparing a business case considering alternative options for treatment of wastewater from both Omakau and Alexandra.