Lake Pupuke Diesel Spill – One Year Later, What Lessons Have We Learned?

One to three hundred litres of diesel spill is a lot for a closed ecosystem to cope with. That is what entered Lake Pupuke from an Auckland Hospital generator in June last year – a lake with only subterranean flows as outlets.

A chain of unfortunate events at the hospital including a faulty valve, holes in a diesel containment tank, and heavy rain overwhelming storm water filters were blamed as the situation went from bad to worse.

One year on, what have we learned from this incident?

As someone that kept a close ear to the ground at the time, I think one of the biggest lessons is: try to ‘close case’ on locals and environmentalists, and you might just get a flood.

One day after the spill was initially reported to Council by a local resident, the hospital managed to contain the leak at its source. But as the rain persisted, diesel flushing into the lake via stormwater pipes continued. And so continued the line of inquiries.

A Waitemata District Health Board spokesperson failed to reassure: “It is not yet known how much diesel has seeped out but the volume is believed to be relatively small. The seepage has been fully contained and poses no further threat to the lake”.

Residents slammed the WDHB and Auckland Council for using minimising words such as ‘seepage’ and ‘small amount of diesel’ to describe a significant environmental disaster that caused the deaths of birds.

Of course, Lake Pupuke is not only popular with wild birds and swans, but with picnickers, paddlers, college rowing crews, divers, and windsurfers. The Pupuke Boating Club operates there. Children were spotted having their Water Wise lessons on the lake a few days after the spill. They weren’t made aware apparently, of the contamination.

Journalists were right to point out that the 90,000 litres of diesel on the North Shore hospital site at any one time is more than double the amount contained in the Ruapehu ski field storage tank that leaked in 2013, causing enormous public outcry. The incident could have been so much worse.

But having supremely nervous staff taken to task by journalists serves no purpose, without measures taken to ensure a repeat incident never occurs again.

In a memo provided to the Devonport-Takapuna Local Board earlier this year, the WDHB states that it has engaged Beca to review the existing system and provide recommendations to minimise the risk of a similar event.

They have also commissioned an incident report to establish what caused the diesel spill and recommendations in the report are being carried out progressively. To date changes include: improvements to the generator maintenance plan and fuel transfer protocols, the frequency of monitoring and maintenance checks has increased, Beca has been commissioned to design changes to the automated monitoring alarm system and transfer systems.

The fault-producing conditions have not been able to be replicated, and it is believed that the diesel overflow from the tank could have been caused by three means: the diesel filtering system, the diesel transfer system or, human error.

Safeguards for the environment and people’s health always need to be top of mind. Thanks to public pressure, it looks like that lesson may have been taken to heart.

The photos below give a look back of the June 2016 incident:

A local photographer took a photo of oiled birds, including the distressed an oiled swan

A photo I took two days after the spill. The smell of diesel remained strong.

Four days after the spill, I helped DOC and Council staff with their boat while they investigated the health of the birds. Two coots were taken away to the bird rescue centre at Ambury Farm in Manukau. For oiled birds, it can take up to two weeks for them to get their water proofing back and can therefore be released back into the wild.