Remote Canadian city overcomes mysterious ‘Void’ challenge

The City of Iqaluit, with a population of about 8,500, is the capital of the Canadian territory of Nunavut and is about 1,275 miles north of Montreal. During winter months, Iqaluit is accessible only by air, which makes importing goods, like bottled water, expensive and time consuming.

In October 2021, this remote community experienced a mysterious problem with its water. Iqaluit residents began complaining that their tap water smelled like gasoline. This led to the territory’s chief public health officer issuing a “Do Not Consume” water quality advisory. (Pictured above, Iqaluit water treatment plant.)

Even with the arrival of emergency shipments of bottled water, limited access to potable water put stress on consumers, including the local hospital, which was struggling to sterilize its equipment.

WSP, an engineering firm with offices all over the world, was called in to inspect the water treatment plant (pictured left). The field investigation team uncovered an unusual underground cavity beneath the water treatment plant that the team dubbed “The Void.” Inside the Void was a large and severely deteriorated fuel storage tank leaking a pool of an oil-like substance along the bedrock.

“Iqaluit’s remote location presented a couple different challenges,” explained Ian Moran, WSP’s process design and optimization engineer. “We were dealing with a harsh winter, which placed added stress to find alternatives to bottled water and portable water treatment units.

“It took about a week for us to ship samples to a lab down south and get results back. We were making critical decisions with week-old data. There was no way to tell consumers what the water quality was ‘today’,” Moran said.

To manage the situation, the team used an onsite spectrophotometer. “The system was installed and calibrated to detect petroleum hydrocarbons in real time,” said Dr. Charles Goss, WSP water quality specialist and professional chemist. “Depending on what wavelength of light is absorbed, the system can correlate it to the presence of different contaminants such as petroleum hydrocarbons. The more you absorb at certain wavelengths, the more of the contaminant.”

Less than a week into the investigation, the team identified the complex pathway the contamination used to enter the drinking water supply and quickly severed it, which restored water quality and reduced the stream of consumer complaints. The rapid reduction in contamination was validated by the spectrophotometer.

“In the end, our swift response prevented contamination levels from increasing beyond any health limits and allowed us to avoid a much more serious situation,” said Justin Rak-Banville, WSP’s director of water and wastewater in the Canadian Prairies.

Having identified the source of the contamination, the team was able to remediate the site and design and implement upgrades to the water treatment plant, including:

• Construction of an emergency water treatment plant bypass system for future emergencies
• Cleaning the oil-like product from the bottom of the Void
• Removing the 60-year-old underground fuel storage tank
• Performing a Phase II Environmental Site Assessment to provide reassurance of no other site contamination
• Developing an emergency response plan, standard operating procedures, and updates to the city’s monitoring and reporting plans

Unfortunately, a similar odor returned three months later.

“This time, we were ready,” said Goss. “The spectrophotometer gave us an early warning of hydrocarbons and we turned the new bypass system on right away.”

The WSP team returned to perform a more comprehensive investigation of all the underground tanks. While part of the WSP team conducted the investigation, another part of the team worked to protect the public’s health.

“Some of the concrete in the treated water tanks broke off and revealed a black, tar-like substance,” explained Moran. “This was a completely-separate hydrocarbon contamination event.”

After testing the substance with the onsite spectrophotometer, investigators determined an improperly installed waterstop product was the reason for the second wave of complaints.

Following the discovery, WSP worked with the city to chisel out all the tar-like substance and added protective concrete reinstatement material and waterproofing to further mitigate the risk of this happening again.

All of the upgrades were successfully implemented, and a return-to-service plan was executed in January 2023.

“The response to the City of Iqaluit and WSP’s efforts during the investigation and upon release of hydrocarbon-free water quality results has been overwhelmingly positive,” said Rak-Banville. “Furthermore, the combined efforts of WSP and the city restored a 60-year-old water treatment plant in the Canadian arctic into a safe and sustainable facility for years to come.”