Otago Regional Council staff have started an investigation into Tuesday's spill which sent wastewater flowing into Horne Creek. Environmental monitoring and operations director Jeff Donaldson said the council could ''instigate some action''.
After the latest spill, on Tuesday afternoon, the council sent a staff member out to observe and determine what happened.
The spill, from a manhole in Stanley St, resulted in about 2000 litres of wastewater entering Horne Creek, which flows into Lake Wakatipu, after congealed fat built up and blocked a pipe.
QLDC chief executive Adam Feeley said ''in recent weeks QLDC has been developing a plan of action to deal with a recent spate'' of spills.
Mr Feeley said the level of preventive maintenance of the sewer pipes should be increased and this would begin immediately.
Key elements of this included ''a fourfold increase in the waterblasting'' of the pipe network, reprioritising maintenance to identify high-risk areas in the network and increased use of CCTV cameras to identify problems likely to result in a blockage.
Mr Feeley said the council would target all food premises to ensure staff were aware of the consequences of putting fats or oils into wastewater drains.
Last month, the ODT reported that in the past year there had been nine unauthorised sewage spills into Lake Wakatipu.
''What we are worried about is their [QLDC] infrastructure is failing and causing pollution ... which is [then] our responsibility'', Mr Donaldson said.
E. coli was present on Tuesday, but by Thursday results were clear. A trade waste bylaw, which would make it easier to prosecute offenders, is being prepared by the QLDC, to be considered at its March meeting.
Rather than having concern about the council's infrastructure, Mr Feeley said, the council was concerned about what people were putting into it.
