Coalition for the West Credit River

Why the FUSS About Temperature?

The West Credit River between the Town of Erin and the Village of Belfountain is longest continuous stretch of Brook Trout Habitat remaining in the Credit River Watershed.  It is the Crown Jewel of the Brook Trout fishery in Southern Ontario. 

Brook Trout are the native trout species in Eastern Canada.  They are found in cold clear streams fed by groundwater.  Their survival relies on stream temperatures no greater than 19oC – 20oC for any sustained period of time.

Location of the Erin WWTP and Effluent Discharge

The Coalition is concerned that the Brook Trout population in the West Credit River will be placed at risk of drastic demise as a result of the sewage plant effluent discharged from the Town of Erin Wastewater Treatment Plant into the West Credit River. 

The Coalition is specifically concerned that the thermal impacts of the plant have been minimized and government agency comments suppressed.

In 2019 Jeff Yurek, the sitting Minister of Environment Conservation and Parks, approved the Erin Wastewater Treatment Plant Environmental Study Report (ESR) without a temperature limit criteria on the sewage plant effluent.  

No reason was provided for the removal of the temperature limit criteria from the draft ESR  despite all reviewing agencies expressing concern about temperature and suggesting a maximum effluent temperature limit should be included in the ESR (Click here to see Government Agency Comments).  

Juvenile Brook Trout Holding in the West Credit River. Photo by Steve Noakes of Trout Unlimited Canada

An important part of the Erin ESR was a Thermal Assessment.  The Thermal Assessment had the stated purpose:

to provide an assessment of the potential effect of the Erin WWTP on the water temperatures of the West Credit River during all times of the year for both Phase 1 (near term and Full Build Out (FBO) (20 year horizon) of the WWTP project and to assess potential impacts to Brook Trout

The Thermal Assessment used one year of effluent temperature data from 2017, a cold year, and did not account for an increase in river, air and effluent temperatures due to climate change over the 20 year life of the WWTP.  

The summer of 2017 was colder than other years.

Daily Average Air Temperatures at Elora Environment Canada Weather Station RCS Weather Station. (Station ID 6142286).  Data from this graph is available in the Data Library. 

To learn more about the thermal impacts of wastewater treatment plant the Coalition for the West Credit River installed temperature loggers in the effluent of five southern Ontario sewage treatment plants. 

Data was collected because the Thermal Assessment did not provide temperature data and an access request under the Freedom of Information and Protection of Privacy Act submitted in December 2020 requesting Performance Reports for the Orangeville, Fergus and Elora wastewater treatment plants has to date been unfulfilled.

Many of the posts in this blog display and review the results of the temperature studies as they become available.