Whitehorse’s water source at risk for fuel contamination, report says

Consultant hired by city found many fuel storage tanks pose contamination risk to aquifer in Riverdale

by Dave Croft, originally posted on December 6, 2016


Whitehorse city staff is recommending a new bylaw to regulate fuel storage in the city, after a study found aging fuel storage tanks in the Riverdale neighbourhood pose a significant contamination risk to the city’s drinking water.

The city draws its water from the Selkirk aquifer beneath Riverdale. Four wells are in the Selkirk Elementary School area, where the city says the water table is 2.5 to 3.5 metres deep.

A study was done by an environmental consultant — commissioned by city council in 2013 at the request of the territorial government — to assess the safety of the water supply.

As part of the study, the consultant did a door-to-door survey of 85 homes and 12 commercial users in the area. According to a city staff report, 70 per cent of the fuel tanks were found to be in “the high risk category due to poor installation, a lack of maintenance, and/or tank quality issues.”

The city’s manager of water services, Dave Albisser, told city council members Monday that the city should pass a bylaw that requires testing and maintenance on all fuel tanks. He said it could apply to just the Riverdale area, or the whole city.

Albisser said of particular concern are three 50,000 litre underground fuel tanks at the Riverdale Super A gas station, and underground tanks at three schools.

He said if the ground water is contaminated, the four wells in the Selkirk school area would have be shut down permanently.

Three wells at a farther distance could still used, but at peak demand the city would have to draw water from Schwatka Lake, and that would trigger a boil water advisory, Albisser said.

A spokesperson for Yukon’s department of highways and public works said all of the Riverdale school tanks have been replaced in recent years. An employee at the Riverdale Super A said the owner is out of town and not available for comment.

Detecting leaks

Councillor Roslyn Woodcock asked why the city is only asking for testing to be done.

“Given that risk, I’m amazed that we didn’t… the lead-in wasn’t that ‘we want these tanks out.’ I realize it’s not going to happen tomorrow, but it seems to me the end result is we need these tanks out of the ground,” Woodcock said.

Albisser replied that another approach is to detect leaks early on.

“It may seem like a very passive, or not a very aggressive, approach,” he admitted.

“However, the hydrocarbon plume in the ground does tend to flow quite slowly, it’s likely several years out before a contaminant that is 300 metres or so away from those wells, that it would reach those wells.”

Albisser said the city is also installing a line of monitoring wells that will indicate if the ground water is becoming contaminated.

He also said that if any fuel tank is found to be leaking, “we would likely require that those tanks be abandoned, however there’s significant financial impact to that.”

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