Why is a new water treatment system needed?

The Comox Valley Water System, which provides drinking water to 45,000 residents, is not compliant with the provincial surface water treatment objectives guideline. As a result, the current operating permit, issued by Island Health, requires a new water filtration plant to be constructed.

The new system will eliminate the need for turbidity-related boil water notices and remove the risk of viruses and bacteria in our drinking water.

What are BC's surface water treatment standards?

The Province of British Columbia's surface water treatment guideline has five objectives for safe drinking water:

  1. Inactivation of viruses
  2. Protection against parasites
  3. Two treatment processes
  4. Less than or equal to 1 nephelometric turbidity unit (NTU)
  5. No detectable E. Coli, fecal coliform and total coliform in the water

What will the new system include?

The new treatment plant will use filtration, ultra-violet treatment and chlorination to remove the risk of bacteria, parasites and viruses from the water and eliminate the need for turbidity related boil water notices.

The new water treatment system will consist of a new:

  • Lake intake
  • Pump station near the intake and raw water pipeline
  • Water Treatment Plant including filtration and disinfection
  • Treated water pipeline from the Water Treatment Plan to the water distribution system.

Is Comox Lake a safe source of drinking water given the recreational and other activities that occur in and around the watershed?

Ensuring safe drinking water requires a two-fold approach: treating the water provided to residents and projecting the water at the source.

The area of land that drains into Comox Lake is approximately 461 square kilometers and includes many smaller, sub-watersheds. The Comox Lake watershed's health depends on activities in the area, as well as the natural composition of the land, including vegetation, wildlife and weather patterns.

In 2016, the CVRD completed the Comox Lake Watershed Protection Plan to guide management of the Comox Lake watershed for the long-term protection of drinking water. Implementation of the Plan requires a collaborative effort by all stakeholders. It identifies 29 water source risks and includes 54 recommendations for risk mitigation. High priority actions, such as water quality monitoring, turbidity source studies, hydrodynamic modeling, emergency preparedness, and education and outreach, are being implemented now.

A major challenge for the Comox Lake watershed is that it is largely privately-owned. Most of the watershed falls under the Private Managed Forest Land Act, and the lake itself is a reservoir controlled by BC Hydro for hydroelectric power generation, maintaining fish flows and flood mitigation. It is also a popular recreation destination for swimming, boating, fishing and hiking.

The water quality in Comox Lake is generally excellent with the exception of during major rain events. The new water treatment plant will be able to treat the water effectively with filtration during those events in the future.