Iqaluit water contamination caused by two incidents, experts say

On Thursday, experts from the engineering firm WSP presented Iqaluit city councilors with the findings of a report commissioned by the city in the fall. Their objective was to better understand the origin of the contamination which led to the establishment of a state of emergency for several months.

For nearly two months, the approximately 8,000 residents of Iqaluit were unable to drink tap water, as it had been contaminated with hydrocarbons.

Traces of fuel were also detected last January, when residents reported smelling it in the water.

In October, fuel vapors from a damaged fuel tank seeped into a buffer tank before reaching the raw water tank, where they contaminated the filtered water supply, the report concludes.

Then, in January, experts instead determined that the contamination was caused by a tar-like substance that had been applied to concrete holding tanks in 2003.

A contaminated underground empty space

In October, engineers from the firm WSP inspected several key places in the drinking water supply chain, including the municipal water treatment plant and Lake Géraldine, which is the reservoir for drinking water. ‘Iqaluit.

Examining an underground empty space between the processing plant and bedrock, engineers found an old, rusty storage tank whose contents had spilled into the ground.

In this empty space, we found the presence of an old underground fuel storage tank in an advanced state of deterioration.explained water treatment design engineer Ian Moran, of WSP Canada, during a presentation to city councillors.

According to Ian Moran, the investigation revealed that an underground booster tank had been partially submerged in the contaminated water. Experts also found fuel contamination on the walls, a ladder […] and on the surface of the water a raw water storage tank, where the water is kept before being filtered.

Following this discovery, the City isolated the contaminated water tank and then removed the tank, which was around sixty years old.

A second source of contamination

Between January 14 and 17, the City received more than 100 complaints from Iqaluit residents about odors coming back from drinking water, leading the Government of Nunavut to implement a nine-day boil water advisory.

According to the engineers, this contamination is attributable to a tar-like substance that had been applied to concrete holding tanks as a sealant. Over time, the latter deteriorated and came into contact with the water in the reservoirs, the city said in a press release.

If this substance was compliant at the time of the work, in 2003, it is no longer used or authorized in the construction work of treatment centers today.

Iqaluit uses the water treatment bypass system which uses ultraviolet disinfection followed by chlorination of Lake Geraldine water to avoid contact with underground reservoirs, the consultants explained in the presentation.

In April, Ottawa also announced $214 million in funding for the construction of a new reservoir system and improvements to Iqaluit’s water distribution system.