Old underground fuel tanks in Riverdale have Whitehorse officials calling for better rules to protect the city’s drinking water.
In 2014, a consultant for the city surveyed 85 Riverdale homes and 12 commercial fuel tanks in the neighbourhood.
“We found in that survey that about 70 per cent of the tanks in that area were of high risk due to poor installation, or a lack of maintenance, or tank quality issues,” Dave Albisser, the city’s manager of water and waste services, told council on Monday.
That’s particularly problematic in Riverdale because the Selkirk aquifer is close by, he said.
The aquifer — near Selkirk Elementary School and the Selkirk pump station — has been the sole source of drinking water for the city since 2010.
Water from this aquifer comes from seven wells ranging from about 21 to 44 metres in depth.
The water level in the four wells near Selkirk Elementary School varies from 2.5 to 3.5 m below ground level.
“Should fuel oil or gasoline leak into the Selkirk aquifer, it may be damaged permanently, and the city would likely have to abandon supply wells near the spill,” Albisser said.
Staff want city council to allow them to create a new bylaw that regulates all fuel storage tanks in the city.
The biggest concern right now are three old underground tanks being used by the Riverdale gas station, Albisser said.
Those 50,000-litre tanks are at least 25 years old and were put in the ground before any sort of regulations were in place that would require them to be permitted. The city has no information about them.
“So we have those tanks sitting over there that have never been inspected?” Coun. Betty Irwin asked.
Albisser said yes and called those tanks “the highest risk to the aquifer.”
Council was told three other underground storage tanks in Riverdale are owned by the Yukon government. A spokesperson for the Department of Highways and Public Works told the News those tanks, used by schools, have already been replaced with the above-ground variety.
A leak into the aquifer would be devastating, Albisser said. No aquifer like the one used by the city has ever been fixed once it is contaminated with fuel. Each well costs about $1 million.
The city could be forced to go back to getting water from Schwatka Lake, which would require a boil water advisory.
“Recently drilled wells located to the south of Riverdale, essentially up the Chadburn Lake Road a little ways, are less susceptible to contamination,” he said. “However, these will meet most of the city’s demands, but not peak demands.”
In Whitehorse, fuel tanks that hold less than 2,500 litres are regulated by the city. Tanks that hold more than 4,000 litres are regulated by the territorial government through the fire marshal’s office. Nobody regulates tanks between 2,500 and 4,000 litres.
Smaller tanks are no longer allowed to be installed below ground.
Larger commercial tanks can still be installed underground if they meet all of the installation safety standards, according to the fire marshal’s office.
Since 1997, fuel tanks are inspected when they’re installed and when they’re removed.
Keeping an eye on them when they are being used, and using them correctly, is the responsibility of the owner and is often required by insurance companies.
“It’s up to everybody to have annual maintenance. I would certainly expect it of myself and others to maintain their equipment,” said Doug Thorseth, the city’s building inspections supervisor.
For permitted commercial tanks, that means taking precautions like keeping logs of how full tanks are to make sure nothing is leaking.
In December 2015, the Yukon government enacted regulatory changes that require all installations or modifications to oil-fired appliances, including their storage tanks, to be completed by certified oil-burner mechanics. But those rules don’t apply to existing tanks, Albisser said.
The city can create rules for all types of storage tanks, even the larger ones that are permitted by the territorial government, he told the News.
Albisser outlined what a new bylaw could look like.
Underground tanks could be subject to “vacuum tests” every year or two, he said. A local contractor places a vacuum on a tank and if the seal holds that indicates there’s no leaks, he said.
Above-ground tanks could follow rules similar to Ontario’s, he said. There, tags are put on a tank when it is inspected and fuel companies can continue to deliver until that tag expires.
“We don’t foresee it being invasive or disruptive or really that onerous,” he said.
Details that still have to be worked out include whether the new bylaw would cover all of Whitehorse or just Riverdale.
Albisser told council a new bylaw would take about a year to create. Some councillors seemed alarmed that it would take so long.
But Albisser said fuel moves slowly when it seeps into the ground.
It would likely take several years for a contaminant to move the 300 metres to the wells, he said.
The city already has one monitoring well in Riverdale, and is planning to install more. Those are tested twice a year and provide an early warning system.
Albisser said staff plan to keep meeting with industry officials to work out details. Council will vote next week whether to officially begin drafting a new bylaw.
Contact Ashley Joannou at ashleyj@yukon-news.com