After a week of running chlorine in the Olalla water system, as of July 4 the Regional District of Okanagan Similkameen (RDOS) turned it off again as efforts to identify the source of contamination continues.
When the last period of chlorination was announced on June 27, the RDOS added that it was planning the change how the water system was configured to try to nail down the source of the problem.
Since September 2024, the RDOS has been working to identify the source of bacteriological contamination in the water system.
The current belief is that the contamination is coming from somewhere in the distribution system.
Previously, the RDOS looked at whether the contamination was coming from the system's storage reservoir, which they isolated from the rest of the system in June.
Previous testing of the source well did not find any signs of coliform bacteria.
Due to the changes in how the system was set up, the RDOS noted that even when chlorination wasn't active, residents should boil all water for at least one minute before use, because the levels of chlorine might not be enough to kill all bacteria in the system.
The boil water notice for residents remains active, and the RDOS stated it is imperative for residents to follow the notice while the chlorination is paused.
Until the boil water notice is removed, residents are being told to use a safe alternative source of water or to boil water for a minimum of one minute before any drinking, brushing teeth, food preparation/cooking purposes, and ice making.
The pause in chlorination was done in consultation with Interior Health
The RDOS is also advising residents to ensure that they are signed up to the Voyent Alert! system for notifications, because the plan is to turn chlorination on and off to track the growth and find the source of the contamination, though the RDOS doesn't have the resources to hand-deliver notices for every system change. Notifications will also be issued through email and/or by phone for changes to the water system.
One possible source that has been studied is potential cross-connections from untreated irrigation water entering the treated water system, such as backflow from an untreated line down the drinking water pipes. These connections most often occur at properties that are connected to the water system and to a privately-owned well.
The RDOS has also asked residents to check their own pipes and hookups to make sure there are no leaks, as a large-scale leak on private property may also be a cause of the contamination.
For further information, or to report a possible cross-connection, please contact RDOS Public Works at 250-490-4106 or 250-490-4135 during regular business hours, 8:30 a.m. to 4:30 p.m. Monday through Friday.
To register for water notifications and other alerts, including emergency notices and evacuations, visit rdos.bc.ca/newsandevents/notifications.
