Wastewater Treatment Plant Expansion and Improvements

Overview | Construction of a new secondary clarifier and concentric ring bioreactor.

This upgrade will increase treatment capacity, provide system redundancy, increased seismic and flood resiliency, improve plant performance and effluent quality, decrease biosolids production and associated energy usage, and carbon emissions and handling costs. 

The Squamish WWTP is currently operating at close to full capacity and requires upgrades to meet population growth forecasts and redundancy requirements in accordance with the Municipal Wastewater Regulations, namely 75% biological treatment capacity with the largest unit out of service, currently, the plant only has 55% redundancy and will only have 35% redundancy based on projected future design flows.

The existing treatment units proposed to be replaced are at risk due to the advanced age of infrastructure, deteriorating condition and minimal seismic and flood protection design considerations at the time of original construction. The new infrastructure will be designed for post-disaster operability and able to withstand seismic and flood events. These upgrades are of the highest priority to the District of Squamish, especially considering the recent flooding events across BC and the lessons learned from the major impacts flooding had on Merritt’s WWTP.

The major upgrade works include:

  • Construction of new secondary clarifier and concentric ring bioreactor.
  • Conversion of an old clarifier tank into a primary clarifier (optimize existing infrastructure and create ongoing value from old infrastructure throughout its remaining useful life).
  • New septage receiving station (septic systems from Squamish and recreational sites along the Sea to Sky corridor will benefit from the improved septic receiving station).
  • Electrical and control system upgrades.

Site Plan:

Site plan

New Clarifier Design

New clarifier drawing.

Environmental benefits:

  • District currently produces 45,000kg of CO2 emissions annually from trucking biosolids to the Callaghan Composting Facility. This project will reduce biosolids production by approximately 10% resulting in a considerable reduction in CO2 emissions.
  • This upgrade will reduce aeration requirements in the treatment process resulting in a 35% reduction in electricity consumption for aeration helping the District to achieve its municipal energy and emissions reduction targets.


Construction is anticipated to take place from late April 2022 through to Sept. 2023.


Construction Progress
June 2022
June 2022

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