DELHI, ON – Norfolk water technicians took corrective action this weekend after a sample tested in Delhi produced an unacceptably high concentration of fluoride.
Several hundred cubic metres of water were withdrawn from the town’s supply and flushed on Saturday. Technicians acted after a routine sample tested in excess of the province’s allowable limit of 1.5 milligrams per litre.
“We probably flushed more than we needed to, but we figured we would be better off to err on the safe side,” Bob Fields, Norfolk’s manager of environmental services, said Monday.
Fluoride is a naturally-occurring mineral. It is added to municipal water to prevent tooth decay. Municipal water in Norfolk is fluoridated in Simcoe, Delhi and Courtland but not in Waterford, Port Dover, Port Rowan and St. Williams.
Fluoride is introduced to the municipal system in the form of hydrofluorosilicic acid. The chemical is highly corrosive. Technicians must wear protective gear while handling it.
Norfolk public works is unable to say how high the fluoride level in Delhi rose on Saturday. The gauges measuring fluoride in Delhi maxed out at their 2-milligrams-per-litre limit. Fluoride levels in Norfolk are normally maintained in the range of 0.5 and 0.8 milligrams per litre.
Technicians estimated how much water needed flushing by taking samples from hydrants and testing stations within several blocks of the Delhi plant.
On the basis of this testing, they are confident they retrieved the suspect water and got rid of it. Water with abnormally high levels of hydrofluorosilicic acid can make people sick but Norfolk public works is unaware of any complaints.
The problem in Delhi was traced to a faulty injection pump. The pump was repaired and put back in service. The Ministry of the Environment and the Haldimand-Norfolk Health Unit have been advised of the incident.
“Both agencies were satisfied with Norfolk County’s response and corrective action,” the county said Monday in a news release.