Raetihi residents will soon be back to drinking water sourced from the Makotuku Stream, which was contaminated by a massive diesel spill last October - even though trapped diesel remains in the waterway.
The spill, from a faulty tank supplying the Turoa skifield on Mt Ruapehu, leaked 19,000 litres of diesel into the Makotuku Stream, forcing the Ruapehu District Council to switch the water source for Raetihi township to the Makara Stream.
The spill provoked a major multi-agency civil defence operation, including the provision of emergency drinking water supplies for two weeks while Raetihi was without reticulated tap water.
The cleanup is estimated to have cost the council more than $600,000, with half the money going on welfare assistance for Raetihi townsfolk and half on restoring the water supply.
Ruapehu chief executive Peter Till said the Horizons Regional Council, which is responsible for cleaning up the diesel spill, had decontaminated as much of the stream as possible.
"Horizons states there is still some diesel contamination trapped within the scree slopes on Mt Ruapehu that has been deemed to be impractical to recover."
Mr Till said there was a risk some of the trapped diesel would find its way into the Makotuku during significant rainfalls.
The council hopes to advise residents of the date for the switch back to the Makotuku Stream in a fortnight.
They are waiting for more adverse weather conditions to rigorously test a hydrocarbon sensor on the raw water line from the Makotuku feeding into the Raetihi water treatment plant settling ponds.
However, Mr Till said the recently installed sensor had been able to detect less than one fifth of a teaspoon of diesel in 20 litres of water. The waterline automatically switches off when diesel is detected. "The settling ponds and tank hold a day's worth of water usage and council is able to switch back to the Makara Stream as a raw water source within hours, ensuring water supply to the township is not affected," he said.
Meanwhile, the organisers of a collective action against the insurers of Ruapehu Alpine Lifts are continuing with their plans.
Raetihi lawyer Jeremy Nash said he expected to be in a position to file the collective claim against the insurers of Ruapehu Alpine Lifts by mid-year. The claim, if successful, could result in payments of between $1000 for affected individuals and up to $3000 for families.
- Waikato Times