The level of arsenic in White Rock’s drinking water has climbed from “nearly undetectable” to “about 40 per cent of the maximum level allowed by Health Canada,” officials say.
But the municipality’s water remains within the range for safe and healthy water, according to a city news release announcing the increase.
“White Rock’s water plant design objectives are stringent, and the city is taking action to reduce the level,” the release, issued Friday, states.
The city’s water quality “continues to be very high… exceeding the standards set for water quality by Health Canada,” White Rock Mayor Darryl Walker adds.
According to the release, the “slightly elevated” presence is “thought to be related to challenges experienced during plant commissioning” – which occurred in April – and tests are underway to return the levels to previously set objectives of less than 0.002 mg per litre for 95 per cent of operation and less than 0.005 mg for five per cent of operation.
The maximum allowed concentration (MAC) is 0.01 mg per litre.
Asked to elaborate on the cited challenges, the city’s communications manager pointed to a September 2019 ‘Update on the Water Treatment Plant to the Water Community Advisory Panel.’
The update lists two issues that needed to be resolved: a software issue that was affecting the recording of data; and, that the filtration of arsenic was not within the range promised in the contract between the city and the manufacturer.
“Staff is working with the manufacturer to address this issue,” the update notes.
Friday’s release notes that the level of manganese in the city’s water – Canadian guidelines issued in May establish a MAC of 0.12 mg per litre – “has continued to be nearly undetectable.”
The city acquired the utility from Epcor in 2015. After partnering with UBC-based research and development team RES’EAU-WaterNET in 2016, White Rock developed an approach to water treatment that includes use of GreensandPlus, a black filter media that removes soluble iron, manganese, hydrogen sulfide and radium from groundwater, plus Bayoxide 33, an absorptive media for arsenic.
In June, city utilities manager Dr. Saad Jasim told council that White Rock water was more than measuring up to current health standards.
The plant generates its own ozone for use in oxidizing the toxic form of arsenic into non-toxic arsenate, which can then be absorbed and disposed of safely with the filtering media, Saad noted.
He also noted that study has shown presence of arsenic and manganese in the White Rock system fluctuates during the year, with more leaching taking place during the winter months.
Friday’s news release notes White Rock’s water has elevated levels of naturally occurring arsenic and manganese. Results of testing triggered by the increase in arsenic will be available later this fall, it adds. The city posts test results at whiterockcity.ca/mywater