Dave Mazey at Tuesday night's public meeting in Raetihi. Photo / Bevan Conley
The man who has been the public face of Turoa during the diesel spill crisis says a disconnected pipe, not the tank, was at fault.
Dave Mazey, chief executive of Ruapehu Alpine Lifts for 28 years, told the Chronicle the leak was discovered on September 27 and the pump atop the tank immediately turned off.
"The initial assessment of diesel observed around the tank clearly indicated a minor leak, plus we had sluices in place which would have stopped any leak from the tank within five minutes.
"On Tuesday or Wednesday, our monthly dip was conducted to check the tank's levels and we couldn't reconcile the numbers, and staff started to think it was the leak. That's when DoC, firstly, and the [Ruapehu] District Council were notified."
Mr Mazey said the 40,000-litre capacity tank was double-skinned, as a bund would not work in a mountain environment because of the prospect of snow melt freezing inside. The tank and associated equipment were all proprietary and designed especially for the Turoa site reflecting best practice, and installed around 2008.
"There's a pump in a cabinet on top to draw diesel out to two bowser pumps 30-40m away, and in the cabinet there's a fixed pipe which leads to another, flexible pipe. That connection became disengaged. It was not the tank that gave way."
There were multiple safety layers for the system, "over and above" what was required, but none of these worked.
"We now know there are 19,000 litres unaccounted for."
He said the spill may have been exacerbated by heavy rainfall that night which flushed the diesel down the mountain and into the Makotuku Stream, which feeds the Raetihi water supply. Further, controlled flushing is under way by Horizons Regional Council to try to clear the last remaining chemicals.
"We're still working through ways to facilitate and support the people of Raetihi, we're putting a lot of effort into it. Some of our initial efforts were on, and around, ways to mitigate and ensure there was no further contamination, particularly with removing the contaminated soil.
"We're going to work through the investigation and then review our storage procedures. Whether that means moving the tank or something else, it will come out in the investigation."
On Friday, all storage facilities at Turoa were assessed and reviewed by third parties, as were those as RAL's Whakapapa site. Mr Mazey said there had been another large spill in 1979 at Turoa, plus a smaller one at Whakapapa, but the September 27 spill had a much greater effect.
"The eruptions of the early- and mid-90s were large events, but were natural, and the Whakapapa arson in 2009 presented its own challenges, but this is the first time events or activities on the hill have had such a negative effect on the mountain, the terrain, the national park and, more significantly, the impact on the communities around us.
"There have been some very strong and powerful sentiments expressed from individuals and groups, and I appreciate that."
Mr Mazey has attended the public meetings in Raetihi to speak with the community and on each occasion has apologised on behalf of RAL, saying he accepted that any angst he felt was nothing compared to what they were going through.