Dunedin City Council staff have been consulting 12 property owners at Blanket Bay and Curles Point about adding them to the council's sewer system, at a cost of $382,200 split between all parties.
The move comes after council staff last year acknowledged a "clear and demonstrated need" for a new system, after years of complaints from residents about strong odours and pollution entering the harbour from failing septic tanks in the area.
However, a staff report to this week's infrastructure services committee recommended excluding three other Curles Point properties - at 127, 132 and 143 St Leonards Dr - from the new scheme, to minimise future costs and avoid setting a precedent.
That was despite feedback from other Curles Point owners consulted by the council, many of whom wanted the three properties included because they were possibly contributing to pollution entering the harbour, the report said.
Committee chairman Cr Andrew Noone said the problem was the nature of the soil in the area meant the three properties' septic tank systems did not drain properly, instead "sheeting" down towards the harbour.
Following a debate at Monday's meeting, councillors instead instructed staff to investigate including the three properties in the scheme, he said.
A written covenant or other mechanism would be required to prevent future subdivision of the properties, which would add to council costs, he said.
"At this stage they are still outside [the scheme] . . . but really we are at the point of saying we need to reconsider these three.
"What's ending up in the harbour . . . could be coming from either one of those three properties, or one of the five we have said is able to be part of this proposed wastewater scheme," he said.
Results of the staff investigation would be presented to the council's draft annual plan hearings in January, and funding could be allocated for the 2011-12 financial year, he confirmed.
The costs split was yet to be confirmed, but the council had previously proposed paying 80% of the cost of connecting the original 12 properties, leaving owners to pay 20%.
The additional three property owners could be asked to pay 100% of the cost of connecting their homes, meaning bills of more than $30,000 each, but would have the chance to argue against the size of the bill at next year's annual plan hearings.
