Faulty tank causes diesel spill
July 27, 2005
A diesel tank used to run central heating in a home in Forrest Hill leaked into Wairau Creek last week.
The spill highlighted the environmental risk of aging diesel tanks on residential properties, especially when they are
not checked regularly.
North Shore City Council's pollution prevention co-ordinator, Stephanie Steffens, says in this case the inside of the
tank had corroded without the owners knowing.
"The 1000-litre tank had only been filled that morning, and the weight of the liquid must have punctured the rust spot
at the bottom," she says.
"All the diesel leaked onto the garden, into the sub soil drains and then entered the stormwater system."
People who noticed the smell near Wairau Creek alerted the council's 24/7 Actionline call centre to the potential spill.
The diesel was detected by a pollution prevention officer, where the creek passes under East Coast Rd in Milford.
"Because of the nature of diesel we couldn't clean it up, but we managed to track it to its source through a process of
elimination," says Stephanie Steffens.
"We worked back through the stormwater pipes, testing the water at every intersection, and narrowed it down to three
houses. After speaking with the residents we located the source of the diesel spill, in this case a faulty storage
tank."
Under the Resource Management Act, people who cause pollution can be given an instant environmental infringement notice
of up to $1000, or be prosecuted for up to $200,000 and/or two years in prison.
Because the spill was accidental in this case, the environmental effect was not severe, and the culprits have
co-operated, council will not be pursuing prosecution.
Houses built in the 1970s and 1980s in North Shore City often had either oil or diesel tanks installed to power central
heating.
"These tanks should be checked regularly, both externally and internally. People should be especially aware if they are
running through much more fuel than usual, and make sure they check the ground around the tank too," says Ms Steffens.
"If there is a leak, the tank will have to be repaired, removed or replaced to prevent spills ending up in our streams
and on our beaches."
ENDS