Leaky fuel tank causes oil spill in Cambridge Bay

What’s tiny, can cause lots of damage, and costs thousands of dollars to clean up?

That’s no riddle to Robert Eno, the Government of Nunavut’s chief environmental protection officer.

Eno knows the answer straight-off: it’s a pin-hole leak in a fuel oil tank.

The damage caused by these tiny leaks is also something that people in Cambridge Bay are now familiar with too.

On June 1, a leak hole was detected in a fuel tank behind the building that houses the hamlet office and curling rink.

Between 1,000 and 1,600 litres of heating oil is thought to have leaked out of that tank, Eno said.

After the spill was noticed, some people working nearby at the Kitikmeot Inuit Association, Nunavut Tunngavik Inc. and the Northern store complained of the diesel fumes — and these can be powerful, Eno admitted, although they’re not likely to cause harm unless contained in a closed environment.

Typically, these fuel tank leaks are discovered when the snow melts.

That’s because when tanks are surrounded by snow, you can’t see the leaks from the holes, which can produce a steady stream or simply drip into the snow.

Without snow, the holes can be hard to detect unless you know what you’re looking for.

“On many of the tanks, we have found that the hole on the outside is so perfectly round that it looks like it has been drilled out,” Eno said.

So much so, that some people suspect the leak holes are the result of vandalism.

However, Eno said the holes are generally caused by corrosion. The process, known as “microbial-induced corrosion,” occurs when tiny oil and water-loving critters dig craters into the sludge that accumulates at the bottom of tanks and through the metal.

In the case of the recent leak in Cambridge Bay, the cause of the leak hole is “unknown origin,” Eno said — although it was probably caused by corrosion.

What’s clear is the high cost associated with the clean-up of that mess, which is likely to run into the thousands of dollars.

The spill in Cambridge Bay is now surrounded by berms and trenches, intended to keep the oil from getting into the water where the volume of the spill multiplies by many times.

When that happens, even a small spill can become an out-of-control large spill, Eno said.

“What they [the hamlet of Cambridge Bay staff] have to do now is keep control of the site and keep it from spreading,” he said.

After ground unfreezes in Cambridge Bay, the oil-contaminated soil will be removed. It’s likely to end up in the local landfill, Eno said.

Prevention costs “peanuts” to compared to the hugh cost of cleaning up a fuel tank spill, Eno said.

This spring there have been many similar spills in Nunavut, he said.

“And most of the spills are preventable,” he said.

In winter, it’s important to keep tanks free of snow so you can see a leak.

“The message I want to get out is to inspect your tanks,” Eno said.

The GN has produced a guide to help Nunavummiut keep their fuel tanks in good shape and leak-free. The guide was written for homeowners — but Eno says anyone who has a responsibility for a dwelling should take a look at it.

You can read the guide here.

This is what a pin-hole in a fuel tank look from the outside. The metal surrounding the leak hole is in perfect condition and seemingly “solid and sound,” says Nunavut’s chief environmental protection officer, Robert Eno. (PHOTO BY R.ENO)