Moose Jaw city council learned during the Buffalo Pound Water Treatment Plant’s 2024 annual report that the plant briefly exceeded the maximum acceptable concentration of fluoride in December.
On Dec. 5, 2024, the plant exceeded 1.5 mg/L of fluoride in the Moose Jaw transmission line for approximately 12 minutes. The online analyzer registered 1.73 mg/L, well above the target level of 0.7 mg/L. However, the levels were not confirmed by laboratory tests.
The incident occurred when one of the City of Moose Jaw’s pumps shut down twice during control system upgrades related to the ongoing plant renewal project.
Due to changes being made to the control system, the typical checks and balances were delayed—taking 12 minutes instead of the standard eight.
Once the issue was identified, the system’s computers automatically shut down operations. Both the City of Moose Jaw and the Water Security Agency (WSA) were notified, and a root cause analysis was launched.
Buffalo Pound Water Treatment Plant Corporation president and CEO Ryan Johnson said multiple factors contributed to the incident, although they have not yet pinpointed a specific cause.
“As a precaution, we have not turned the system back on until the SCADA control system is completed,” said Johnson. “That way, Moose Jaw and the plant will be operating on the same system, which will prevent the chance of this happening again.”
The exceedance was measured at 0.2 mg/L above the maximum acceptable concentration. However, Johnson noted that the 20-kilometre transmission line between the plant and Moose Jaw would have diluted the fluoride to levels below 1.5 mg/L before reaching consumers.
He estimated that, taking into account the water already in the pipeline and reservoir, the fluoride level reaching residents likely only rose from 0.7 mg/L to 0.703 mg/L — a negligible increase.
“For the handful of farmers who take water off the supply line between the plant and the city, they use cisterns,” said Johnson. “The chance that someone was drawing water at the exact moment that 1.7 mg/L concentration passed is very low. But even if they had received 100 per cent of that water, their cistern fluoride level would have only risen to 0.86 mg/L — still well below the 1.5 mg/L threshold. The WSA took that into account when reviewing the incident.”
Because the exceedance was not confirmed by lab tests, it is considered a potential exceedance — but it was still treated as an actual one as a precaution.
Had it posed a confirmed health risk, Johnson said the WSA would have intervened and further actions would have been taken.
Original article online at: https://www.discovermoosejaw.com/articles/acceptable-fluoride-levels-in-drinking-water-briefly-exceeded-in-december