NIAGARA ESCARPMENT BIOSPHERE NETWORK BLOG

The Coalition For The West Credit River

15/10/2025

The Erin wastewater treatment facility is scheduled to open this autumn, but the Town of Erin, in Wellington County, is seeking to delay installation of an effluent cooling system. Releasing warm sewage effluent into the West Credit River’s coldwater habitat could have adverse effects on this temperature-sensitive Brook Trout population.

The West Credit River (WCR) has one of the few remaining self-sustaining populations of this native Brook Trout species in southern Ontario.

At full build-out, 7.2 million litres per day of effluent will be discharged into the WCR at Peel Region’s Caledon border and flow into the Niagara Escarpment Biosphere Reserve.

The Coalition for the West Credit River is a community of organizations (Belfountain Community Organization, Freshwater Conservation Canada, the Izaak Walton Flyfishing Club, Ontario Rivers Alliance, and Ontario Streams) collaboratively working to address issues surrounding the Erin Water Resource Recovery Facility, the health of the WCRand its native Brook Trout population. 

The Coalition adopts a collaborative, science-based approach to protecting the WCR’s aquatic ecosystem and works to ensure that treated sewage effluent complies with environmental legislation, and any impacts are effectively addressed.

Coalition for the West Credit River Accomplishments 

Since 2020, the Coalition for the West Credit River has worked to protect one of the few remaining native Brook Trout populations in southern Ontario from the proposed Erin Wastewater Treatment Facility. 

Brook Trout are a sensitive coldwater species that are intolerant of stream temperatures greater than 19°C for any sustained period, and yet the Environmental Study Report failed to include any provision for an effluent temperature limit or an effluent cooling system.

Over the past 5 years, the Coalition has achieved the following:

• Built strong working relationships with the Ministry of Environment, Conservation and Parks (MECP), the Town of Erin, Credit Valley Conservation, and the Region of Peel.

• Done the field-work to collect five years of sewage-effluent temperature data (June-October) from local wastewater treatment facilities to demonstrate potential impacts on stream temperature.

• Used this evidence, together with sustained advocacy, to secure key protections in the facility’s Environmental Compliance Approval (ECA), including:

o Final effluent must be maintained at or below 19°C on a 4-day moving average.

o An Effluent Cooling System must be built into the design and fully operational before the plant can go online.

o Quarterly summaries of all operating issues and corrective actions must be posted to the Town of Erin’s website.

o Real-time water quality and effluent temperature data must also be posted to the Town’s website for public access.

Outreach & Education

Beyond regulatory advocacy, the Coalition is deeply committed to education and stewardship. We deliver presentations and outdoor excursions to local schools, educating and connecting students with Brook Trout and their fragile cold-water habitat.

To learn more about the Coalition for the West Credit River: cwcr.ca