Outfall Relocation Project

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The Joint Utility Board Sewage Treatment Plant is a hybrid secondary/tertiary treatment plant located on the Cowichan River that treats wastewater from North Cowichan, Duncan, Cowichan Bay, Eagle Heights and Cowichan Tribes (the CVRD Central Sector Area). The plant is located on Cowichan Tribes’ land near Duncan and is operated by  North Cowichan. The plant discharges highly treated effluent (cleaned water) into the Cowichan River. While this effluent meets provincial swimming safety standards, it is not clean enough for drinking.  

North Cowichan is working to move the outfall out of the river to a new location at the edge of Cowichan Bay.

There are several reasons to relocate the outfall:

  • The treatment plant is on land leased from Cowichan Tribes. The lease agreement includes a commitment to make a reasonable effort to move the outfall from the Cowichan River.

  • During periods of very low river flow, there is not enough flow to provide the desired amount of effluent dilution. Low river flows are expected to become more frequent in the future.

  • The existing outfall infrastructure is at risk of damage from log jams and gravel accumulation.

  • Moving the outfall from the river may trigger a reassessment of shellfish harvesting in Cowichan Bay.

Proposed outfall location

Studies and public engagement in 2015 identified a proposed outfall location in Cowichan Bay (see map, Stage 1 outfall). Since that time, additional studies and consultations with local First Nations have led to a new proposed location at the edge of Cowichan Bay (see map, Stage 2 outfall).

Map of Cowichan Bay highlighting the proposed outfall locaiton.

The outfall location has been selected to avoid anchorages and known shellfish harvesting areas. There will be significant dilution of the effluent at this location, much more than with the existing outfall. Modelling shows that the discharge will meet federal and provincial standards, even with increased quantities of effluent as the population grows.

Additional monitoring, before and after the outfall is operational, will take place through a Receiving Environment Monitoring Program (PDF).

Work is now underway to determine the preferred route for the pipe that will carry treated effluent from the treatment plant to the outfall. This decision will be based on many factors: environmental, archaeological and cultural studies; consultation with local First Nations, engagement with stakeholder groups and the public; and assessments of the relative cost and feasibility of potential routes.

Radial graph indicating the different factors that lead to the project's routing decision.

Marine routing options

In the ocean environment, the pipe will likely rest on the sea bed. Four routes are under consideration (see map below), entering the marine environment at:

  • Westcan Terminal Road,
  • Hecate Park,
  • Sutherland Drive, or
  • Fairbanks Road (Seaside Road)
Map of Cowichan Bay with highlighted, proposed marine route options.

detailed study (PDF) provides information on the environmental implications of each of these routes. The study assessed potential impacts from pipeline construction and operation. Of the four marine routes:

  • Sutherland Drive and Seaside Road would have the least environmental impact for inter-tidal and marine environments
  • Hecate Park would have moderate impact
  • Westcan Terminal would have the highest environmental impact

Some impacts associated with marine pipelines would be temporary. During installation, possible impacts include trenching along intertidal areas (if required) and installation of anchors to secure the pipe. Other potential impacts include: disturbance, change or loss of habitat; suspended sediments; excessive noise; and fuel spills. Once a preferred marine route is selected, an environmental impact study will recommend best practices, control measures, mitigation and compensation to address any impacts associated with construction.

Land and routing options

Options for land from the sewage treatment plant to the marine environment are;

  • Through Cowichan Tribes lands (either via Tzouhalem Road or through the middle of the Reserve), linking to any one of the four marine access points; or
  • Along the Trans-Canada Highway and Koksilah Road to either Sutherland Drive or Seaside Road
Map of Cowichan Bay with highlighted, proposed land route options.

There are also routing options through Duncan, either along the river berm or along Marchmont Road and Beech Avenue. 

Map of Duncan with highlighted, proposed route options.

Pipes will be placed underground, mostly in road rights-of-way. In some locations, it may be necessary to mount the pipe on existing bridge structures. There will be disruption to traffic during installation, but there should be no long-term impacts.

Ongoing studies

At this time, no decisions have been made with respect to routing. Other alternatives may emerge during additional studies which North Cowichan is undertaking to identify and assess the environmental condition and risk, archaeological and cultural impacts, feasibility, cost and other considerations of land options.

Thanks for your input!

Thank you to everyone who provided input by email, on PlaceSpeak, and during the live webinar.  Your input and comments are included in a report on public engagement found here: JUB Public Engagement Report March 2021 (PDF) 

This phase of public engagement is now closed, however, there will be additional opportunities as the project moves forward.

Watch the video from the March 2021 open house: 

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