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ABBOTSFORD, BC DRINKING WATER
We sent Abbotsford media a series of email questions. The answers are below
Abbotsford and Mission receive domestic water from the Abbotsford Mission Water & Sewer Commission.
Can you describe the drinking water system in Abbotsford, (water source, distribution watermains, treatment plant, users, cost, etc.) and the main challenges it faces?
The City of Abbotsford receives its water from a regional supply system (that also serves the City of Mission). Abbotsford and Mission receive domestic water from the Abbotsford Mission Water & Sewer Commission (AMWSC). The AMWSC draws water from three sources, provides treatment, and transmits the treated water to Abbotsford and Mission. The current estimated service population is 176,000, including Mission.
Norrish Creek, located northeast of Mission, sources from Dickson Lake and provides the bulk of Abbotsford and Mission’s drinking water. Norrish water is filtered by slow sand or ultrafiltration membranes at the Norrish Creek Water Treatment Plant (NCWTP). The water is chlorinated at the plant outlet and then flows 7.5 km to the Bell Road Ammonia & Soda Ash Station, where aqueous ammonia is added to form chloramines for distribution system residual disinfection.
Cannell Lake, located north of Mission, supplies water to consumers located in the higher elevations of Mission. It also supplements supply to Abbotsford when demand is high or when the Norrish supply is off-line. Cannell Lake water is treated by ultraviolet (UV) disinfection and chlorinated 1 km downstream of the intake.
Groundwater Wells - The AMWSC supplements times of high demand with groundwater from the Abbotsford-Sumas aquifer. Most well water is chloraminated prior to distribution.
Current key challenges for the regional system include:
Do the plants have any treatment for emerging contaminants such as PFAS, and endocrine disrupters?
With the increase in extreme weather events and flooding, what measures is your city taking to protect its plants?
- System resiliency - The Norrish Creek infrastructure (intake, Water Treatment Plant access road, and transmission main within that road) is vulnerable to damage in extreme weather events. While Cannell Lake and the groundwater wells are currently able to offset a short-term interruption (i.e. days/weeks) of the Norrish source during typical storm seasons (Oct-Apr), they are unable to do so over a longer term or should an atypical storm occur in summer (May-Sep) when water demands are high. For example, in November 2021 the City of Abbotsford experienced one of Canada’s most costly flooding disasters. At that time, due to two landslides on the service road access as well as rock debris from Norrish Creek covering the water system intake, the Norrish Creek water treatment plant was offline for about eight weeks. During this time, we relied on Cannell Lake water and groundwater wells which was possible given the time of year and wet weather we were experiencing. This wouldn’t be possible in warmer months.
- Climate change – The City expects climate change to impact the water system in several ways. (1) Warmer winters will mean less (or no) snowpack in the upper Norrish watershed, which helps sustain creek flows even after winter rains have subsided. (2) Longer and more extreme summer droughts will increase demands, increase risk of wildfires in the Norrish and Cannell watershed
- A key water transmission lies underneath the Fraser River as part of the regional water supply system, which makes the system vulnerable.
Combined sewage overflows (CSO) are a common problem in cities across Canada. What is the situation in your city? What was the amount of CSO released in recent years?
- A project is in the design phase to improve the resiliency of the Norrish water intake to increase the resiliency of the system during major storm events.
- The City is also working with other stakeholders of the Norrish Water Treatment Plant access road (e.g. logging company and provincial forest district) to mitigate the potential for road failures during such storms.
- A grant application to the Province has been submitted to develop a new water source with vertical wells, to improve the resiliency of the overall water supply system.
Lead connections are also a common problem, how many lead connections do you estimate there are in your system? What is the city doing about it?
- There are no CSO in Abbotsford.
Are there other emerging issues, particular to your city, you are looking into?
- To the best of the City of Abbotsford staff knowledge, there are no lead service connections in the Abbotsford water distribution system.
- Improving seismic resiliency of the water systems.