Public health investigation of swimming pool chlorine gas disinfection systems

In February 2012, a chlorine gas leak at a public pool facility in the British Columbia southern interior sent 70 people to hospital for assessment and treatment. As part of the follow-up investigation, the Interior Health (IH) public health engineering team undertook a comprehensive review of chlorine gas disinfection systems in public pools throughout the region. Deficiencies in the capacity to safely capture and release gas leaks were found in all 19 systems inspected. The engineering team subsequently worked with facility owners and area Environmental Health Officers to mitigate high-risk issues. However, less than half of the facilities were changed to on-site chlorine generation systems. Chlorine gas in public pool facilities poses an inherent risk to public health, and regional health authorities are responsible for routinely inspecting and overseeing these systems. The IH public engineering team continues to advocate for transitioning all public pool chlorine gas systems to less hazardous means of disinfection.