Septic tank issues have been around in Tokoiti and Benhar for a long time. In Benhar's case, the heavy clay soils and poor absorption leave visible evidence of the waste.
Tokoiti resident Lynn Smart says that she, like many others, is worried about the council's plans.
"It's just not possible to pay this much money - we're desperately worried at the cost."
Her concerns are echoed by Benhar residents Phil Barrett and Julie Posthumus, who also say the cost of the scheme is a major concern.
Mr Barrett says residents should be given more time to explore more "affordable" options.
Tokoiti and Benhar residents also miss out on the council's harmonisation policy, designed to create a more uniform set of costs for services across the district. The capital required for new schemes, such as Tokoiti and Benhar, is excluded from this policy.
Other Clutha townships' resource consents for sewage systems are also due to expire in the next 10 years. Heriot's and Kaitangata's expire in 2014, Clinton's and Waihola's in 2017, and Balclutha's in 2018. The treatment plant in Milton's wet-weather overflow consent is also due in 2017.
Clutha District Council manager district assets Jules Witt says expiring resource consents could mean upgrades in those townships.
Waihola township, 35km south of Dunedin, operates an oxidation pond with effluent discharged to the outflow channel of Lake Waihola, but only at low tide.
Otago Regional Council director of resource management Dr Selva Selvarajah says the Waihola system is very basic and the system is likely to need an upgrade when the consent expires. The Waihola system had sometimes struggled to meet consent conditions.
Lawrence, Owaka, Stirling and Tapanui received renewed resource consents on the condition that BioFiltro plants are built, as has Kaka Point which already has a BioFiltro system in place.
Mr Witt says resource consents for the townships' sewage systems expired at different times, but it took the council a while to find an "acceptable solution" to meet consent conditions. It made sense to upgrade the systems at the same time to save money and enable consent expiration dates to occur at the same time - in 35 years, he says.
Work will begin on the four BioFiltro plants in the next few months.
Benhar, Clydevale, Papatowai, Pounawea, Tahakopa, Taieri Mouth, Tokoiti, and Toko Mouth have a large number of septic tanks and lack reticulated systems.
"Papatowai and Pounawea are likely to need upgrades in the near future but it's not a priority at this stage." Mr Witt says.
Dr Selva Selvarajah says Benhar and Tokoiti have a history of septic tank issues. The ORC became involved in 2005, when staff found unsafe levels of bacteria in effluent.
"It's a health issue and it has to be addressed. We are concerned with the time it has taken to address this issue and under the Resource Management Act we have enforcement powers, including issuing infringement and abatement notices and, potentially, prosecution, if issues are ongoing," Dr Selvarajah says.
Under the Resource Management Act, regional councils are required to control discharges of contaminants to water, air and land and discharge of water to water.
The ORC Water Plan allows septic tank discharges up to 2000 litres a day without requiring consents, provided certain conditions are met. However, all industrial and district council discharges, such as sewage discharges, either to water or land, require resource consents from ORC.
"Many other regional councils look at dilution as a solution where we prefer proper treatment to minimise pathogens and bacteria.
"Our first preference is for any sewage to be discharged to land, as opposed to water. In cases where land-based discharges are not possible, we allow water discharge.
"BioFiltro systems meet our requirements with the UV system to kill pathogens and bacteria. The Kaka Point plant is meeting our standards very well, and that's why it received a 35-year consent - the maximum time allowed," Dr Selvarajah says.
He says the $12 million membrane biological reactor plant at Fonterra's Stirling plant is the "perfect system" from the regional council's perspective. Discharge can even be made into waterways due to the "zero bug discharge".
• Verbal submissions on the draft annual plan, including sewage upgrades at Benhar and Tokoiti, will be heard at the Clutha District Council's meeting on Thursday. A special meeting will be held on June 16 to consider all submissions and make any changes to the draft annual plan, with the plan adopted on June 27, and to strike the rates for 2011/12.
