The City of White Rock will begin secondary treatment of the water supply this month as staff phase in the addition of chlorine to the city’s wells.
A city news bulletin last week stated that residents “may notice differences in the taste and appearance” of the water supply as the city moves forward with the disinfection.
City manager Dan Bottrill told Peace Arch News Tuesday that the addition of chlorine will start with a portion of the system before it is phased to all seven wells, and the amount of chlorine slowly increased to meet the required levels by the June 30 Fraser Health deadline.
“We’re starting a little early because we do need a phased approach,” Bottrill said. “We’re going to be putting in a higher strength of chlorine… so we need to determine how that’s going to impact the manganese that already exists within the water lines.
Chlorination has been in place at the Merklin Street reservoir since the 2010 boil-water advisory triggered by the discovery of E.coli in the supply. Following that incident, Fraser Health mandated that the city’s water supply undergo system-wide secondary disinfection.
In December, city staff told council the preferred disinfection method for the city was chloramine – a mix of chlorine and ammonia – due to the high levels of manganese in the supply, which would react with chlorine, causing staining and cloudy water.
The news prompted an outcry from residents, who cited potential negative health, environmental and infrastructure effects of using chloramine, and rallied at city hall less than a month later calling on the city to reverse its decision.
That evening, council voted unanimously to abandon its plans to use chloramine, and treat the water with chlorine instead.
A request by the city for Fraser Health to extend its June 30 disinfection deadline – to give the city time to address the high arsenic and manganese levels – was denied.
Greg St. Louis, the city’s director of engineering and municipal operations, told PAN following council’s decision last month that residents are likely to notice the esthetic effects of chlorine reacting with manganese.
“I don’t believe the water is going to be as clear as it currently is,” St. Louis said.