Construction is officially underway on a new $12.9-million drinking water disinfection facility that will introduce ultraviolet (UV) treatment to the City of Cranbrook’s water system and bring the municipality into compliance with British Columbia’s Drinking Water Treatment Objectives for Surface Water.
The new facility will add UV disinfection and a sodium hypochlorite treatment system to the city’s existing water treatment process, creating a dual-barrier approach designed to improve public health protection, enhance operational safety and strengthen long-term system resilience.
Cranbrook’s water supply is sourced from surface water, which, under provincial Drinking Water Treatment Objectives (DWTO) requires two treatment processes to protect against waterborne pathogens. The city’s current treatment system relies on chlorine gas disinfection, a process that has been in operation since the 1970s, with upgrades completed in the early 2000s.
The new facility will be constructed downstream of Phillips Dam and the existing treatment infrastructure. Once operational, it will replace chlorine gas treatment with UV disinfection and liquid chlorine generated on site.
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According to the city, the transition will eliminate operational risks associated with handling chlorine gas while improving protection against pathogens that are resistant to conventional chlorination.
“Transitioning to liquid chlorine that is generated on site will eliminate the operational safety concerns associated with handling chlorine gas,” the city noted in project materials.
“The DWTO requires two treatment processes to ensure water quality as certain microbiological agents are resistant to certain forms of treatment,” the city noted in a statement. “For example, Cryptosporidium is an extremely chlorine-tolerant parasite that can be effectively inactivated with UV treatment.”
City officials, project partners, consultants, contractors and government representatives gathered on June 2 for a groundbreaking ceremony marking the start of construction on the Phillips Reservoir UV Disinfection Facility, a project years in the making through planning, engineering design and regulatory review.
“This is an important and exciting day where we officially kick off a project that will further protect the city’s water quality and provide safe and clean drinking water for decades to come,” announced Cranbrook Mayor Wayne Price.
Municipal officials say the project is being driven not only by regulatory requirements, but also by the need to improve resilience against changing environmental conditions. Extreme weather events can increase turbidity and introduce additional contaminants into source water, creating greater treatment challenges for utilities that rely on surface water supplies.
The facility is expected to provide enhanced treatment capacity and reliability for Cranbrook’s growing population of more than 20,000 residents while supporting projected community growth over the next 75 years.
City officials also noted that the investment will help defer the need for a significantly more costly filtration plant. By maintaining the current treatment approach while adding a second treatment barrier, Cranbrook can avoid construction of a filtration facility that could exceed $100 million in capital costs and carry substantially higher long-term operating expenses.
Funding for the project was announced in March 2024 through the Investing in Canada Infrastructure Program’s Environmental Quality Stream. The federal and provincial governments committed a combined $9.5 million toward the project, while the City of Cranbrook is contributing approximately $3.4 million.
Construction is expected to continue through 2027, with the Phillips Reservoir UV Disinfection Facility anticipated to be fully operational by the fall of that year.
