What's in the groundwater beneath Whitehorse? Research suggests some high levels of uranium

High levels of heavy metals and metalloids in untreated groundwater have been detected in and around Whitehorse, new research suggests.

Of main concern are arsenic, uranium and manganese, some levels of which preliminary data suggest are above safe drinking water guidelines recommended by the federal government. 

Those results still need to be confirmed through further testing. The water tested is outside of the municipal water system. 

In collaboration between Yukon University, Carleton University, the Yukon government and others, researchers analyzed samples from 182 sites across the city, including residential drinking water wells, environmental monitoring wells and springs. The researchers also used data from previous environmental monitoring studies, and tested surface water on shuttered mines in the copper belt.

The research states that 30 per cent of samples contain uranium above federal limits. One site registered levels 20 times higher than acceptable concentrations set by Health Canada. Gross Alpha — that is, either uranium, radon or radium that emit radioactivity as they decay — exceeded guidelines by 33 per cent. For arsenic and manganese, it's seven and 29 per cent above, respectively. 

The research states excess exposure to these can come with serious health risks, including kidney damage, cancer and impaired brain function.

Mary Samolczyk, an assistant professor of earth sciences at Yukon University, said behind the research is public health.

"I'm passionate about this because it's very important for people to understand what they're drinking," she said.

Groundwater is what most people in Whitehorse drink. Buildings connected to the water main have their water treated with sodium hypochlorite, which targets pathogens, at the Riverdale aquifer. The water is monitored at the pumphouse in the neighbourhood and weekly at several stations along 187 kilometres of pipes throughout the city.

Right now, the city can only treat pure groundwater. There's a possibility surface water could be mixing with groundwater, which could be prompting changes, including to the levels of metals and ions. The city recently faced $39 million pricetag to upgrade the water treatment system, but that's been delayed. Still, staff have said the city's potable water remains safe to drink.

Samolczyk said what's being found in the groundwater is naturally occurring, owing to the fact the city's built upon a lot of mineralization. The issue isn't unique to Whitehorse, she added.

"It's everywhere. We need to check the quality of our groundwater, to make sure that people are drinking what — a quality that Health Canada recommends as safe."

Joel Cubley, an associate professor with Yukon University, said the data suggests bedrock and overburden that could be naturally depositing uranium and other things into the groundwater, which he noted can be treated.

Asked whether historical mining — like what used to happen in the city's copper belt region — could be having an effect on levels so far gauged, Cubley said that connection just can't be made yet, though it's still a research focus.