Motorway poses explosion risk
New Zealand’s most-expensive roading project could harbour potentially explosive consequences, a power company is warning.
Mercury Energy have outlined numerous safety concerns regarding its decommissioned Auckland Southdown Power Station and its proximity to the East-West Link’s (EWL) proposed route.
The EWL is a $1.8 billion connection from State Highway 1 at Sylvia Park to State Highway 20 at Onehunga, which aimed to ease congestion and improve the flow of freight between the two industrial hubs.
The thermal powerstation is on standby and could be fired back into life if Auckland’s power supplies ever faltered.
Mercury Energy’s wholesale markets manager James Flexman said that in the event of a restart, turbines on the station would discharge natural gas close to the motorway.
A low probability but high consequence risk of this would arise if a vehicle which overheated stopped adjacent to a turbine, creating an explosion hazard, Flexman said
‘‘If the East West proposal was located where it is currently proposed, any such explosion could put human life at risk and potentially damage the structural integrity of the proposed road/ pathway,’’ he said.
High energy explosions could also result from generator rotor ruptures and disc failures on gas turbines, he said.
Mercury was requesting a full safety risk assessment be undertaken by the board to identify any further hazards which could arise from the co-location of the EWL and the power station.
New Zealand Transport Agency’s (NZTA) acting system design manager Paul Glucina said it had been working with Mercury Energy since 2014 to mitigate any risks associated with the EWL.
NZTA had completed a risk assessment on information Mercury Energy presented to an EWL board of inquiry and had found the primary issues raised could be managed to an acceptable level, Glucina said.
‘‘We have proposed to the board of inquiry that as a condition of consent we carry out a further risk assessment before any construction starts,’’ she said.
NZTA would continue to work with Mercury to ensure future risks were addressed and a safe route was provided, she said.
An artist impression of the East-West Link along Orpheus Drive near Aotea Sea Scouts building.