Different fuel sources caused fall, winter water contamination, say experts

Engineers from consulting firm give presentation to city council about state of Iqaluit’s water treatment plant

This before-and-after shot of the void at Iqaluit’s water treatment plant shows how much fuel had leaked from an old tank found in the space last fall. (Photo courtesy of the City of Iqaluit)

By David Venn
Local Journalism Initiative Reporter

Black tar found in the concrete walls of underground water tanks at Iqaluit’s water treatment plant caused December and January’s fuel contamination in the water supply — but the water has always been safe to consume, experts hired by the city say.

The contamination levels in residents’ taps remained within Health Canada guidelines and residents could have consumed the water for decades without increasing personal health risk, WSP Canada engineer Ian Moran said at a special city council meeting Thursday evening.

The city hired WSP in October to inspect the water treatment plant and consult the city on how to move forward after fuel was confirmed in the municipal water supply, triggering a Government of Nunavut do-not-consume water advisory that lasted two months.

“The water in the distribution system which includes water coming from consumer taps, has been safely consumed [from Oct. 12 to May 5] with respect to hydrocarbons,” Moran told the public.

Black tar on the walls of an underground tank at Iqaluit’s water treatment plant is to blame for the return of fuel contamination in the water last December and again in January. (Photo courtesy of the City of Iqaluit)

“Even a lifetime exposure to the water during this time would not be expected to increase health risks for any consumer, which includes children.”

Between Oct. 2, when reports started coming in about a fuel smell in the water, and Oct. 12 when the advisory was put in place, people reported headaches, dizziness, stomach aches and skin irritation.

While the tars causing the December and January contaminations were “identical,” the contamination in October was distinctly different. The original event was caused by an old, leaky fuel tank in a part of the water treatment plant known as the “void.”

Moran and water quality specialist Charles Goss were back at city council Thursday to explain what happened during two subsequent fuel contamination events at Iqaluit’s water treatment plant — one in December, another in January.

On Dec. 16, six days after the GN lifted the do-not-consume advisory, the city’s water monitoring system again detected fuel.

WSP inspected an underground tank called a mixing chamber and found that concrete had broken off one of its walls, revealing black tar that had “direct contact with the water” and smelled like fuel, Moran said.

They inspected the other underground tanks, but did not find any more exposed tar.

City officials bypassed the mixing chamber the next day, and that bypass was in place until Jan. 17.

In mid-January, more than 100 residents reported smelling fuel in their water again, and testing revealed heavy lubricants and oils were present in the water.

When they looked again, WSP engineers found black tar in a different chamber, where it wasn’t seen before.

Moran said he believes bypassing the mixing chamber caused the normally calm water in the other chamber to become turbulent, which in turn caused its concrete walls to crumble, revealing more black tar.

It took the city five days after the first complaint to engage a bypass of all the plant’s concrete tanks.

Moran called the response “swift.”

The black tar is known as a waterstop, which is used to stop water from moving through concrete joints. It contains heavy oils and lubricants, which are included in F3 and F4 families of fuel compounds.

The tar was certified to be used around potable water when it was installed close to 20 years ago, but is not any more.

Goss said that doesn’t necessarily mean the product is unsafe. It could mean the manufacturer didn’t go through the certification process again, he said.

Moran said the underground tanks are in good condition otherwise and do not have any more hydrocarbons in them.

“The real issue at this point in time is the exposed waterstop products in the water treatment plant,” Moran said, adding WSP recommends the city remove all of the black tar substance from the tanks and install a concrete layer of protection.

It’s not clear at this point how much that work might cost. Meanwhile, the city is continuing to use its bypass system to avoid the affected tanks.

Coun. Kyle Sheppard asked the experts if there’s any other evidence that the contamination could have been from something else, to which Goss replied no.

“There are elements of our population that might not believe anything that we come up with at this point,” Sheppard said.

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(6) Comments:

  1. Posted by Scotty on

    Who was the engineer in 2003 that put the tar in the walls and why is it even there? Or did the contractor botch the install? Doesn’t sound safe.

    And why wasn’t the old fuel tank pulled out 20 years ago during the upgrades? Probably a case of “not my scope, not my problem”… until 20 years later when it definitely is your problem. There has to be some professional ethics issue with abandoning a full fuel tank in the ground next to a water treatment plant..

  2. Posted by JC on

    Coun. Kyle Sheppard said it was a “big relief to have this information available to provide for residents so that we can hopefully provide some peace of mind going forward.”

    “There’s very compelling evidence and compelling data in this report. To me, it’s undoubted, what the source of this contamination was,” he said.

    “There are elements of our population that might not believe anything that we come up with at this point,” Sheppard said.

  3. Posted by Thomas Shelby on

    Sorry this all still sounds “a little fishy”. Is this all being said so no one will file lawsuits down the road? Possibly.
    In mid Jan when the second issue came about just after the first issue, and they are saying it was a totally different source, this doesn’t make sense to me or seem possible. A little black tar (waterstop) contaminates the water so bad there is a strong fuel smell again seems too convenient of a cause. I would think there would have to be a major amount of exposed tar to cause the strong fuel smell again. Not trying to be a pessimist but still doesn’t seem right to me.

    • Posted by Steve B on

      The City posted the engineer report and fingerprint data on their website. There’s a lot of technical stuff, but I found the images at the back of the report super easy to follow and they’re really well done.
      Apparently new turbulence in one of the tanks caused a ton of the tar stuff to burst out of the wall and a concentrated slug of it made its way into the system.
      Looking at the fingerprint data, the fingerprint from the tar matches the stuff they found in the water (Slide 27). The fingerprint data from October is completely different (Slide 13).
      Hard to fathom two different sources, but the chemistry, data, and (what I understood from) the discussions makes sense to me.

  4. Posted by Jim on

    Fantastic that this was finally found and dealt with to clean up the contaminant. Not sure about the years of exposure being no risk. Just because you don’t have the right test to see a difference doesn’t make it no risk.

    • Posted by JC on

      From Health Canada’s Website:
      “Health Canada’s screening values identify limits for contaminants in water that could be used as a source of drinking water. A lifetime of exposure to these contaminants up to the screening value, both by drinking the water or by using it for showering or bathing, is not expected to increase health risks for any Canadian, including children.

      Screening values are based on a review of scientific research and international regulatory information available at the time of their development. In addition, screening values are externally peer-reviewed to ensure scientific integrity.”

      The screening vale for F2 is 390 ug/L. The screening value for F3 is 290 ug/L.

      The human smell detection for hydrocarbons is 1-3 ug/L. If you get the odd whiff of fuel in the water, you’re probably in this range.

      So yes, you can smell fuel in the water and it’s safe to drink according to Health Canada. Concentrations would need to be 100 times greater than your sense of smell before it becomes unsafe AND you would have to consume this water over the course of your entire lifetime to increase health risks, even for children.

      As for “years of exposure” – if you can’t smell it, you’re even further below Health Canada’s values. No risk.

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