Olymel operates four pig maternities in Témiscamingue and, curiously, the water quality of the Rivière à la Loutre and the Petite rivière Blanche is deteriorating. Could pig manure spreading practices be the cause?
This is the question that theTémiscamingue Watershed Organization (OBVT) has been around for years. And you know what? At Fondation Rivières, we managed to answer the question by carrying out a screening campaign sources of bacteriological contamination of fecal origin (type E.coli).
Conclusion: it is cattle breeding, a non-existent sewage treatment plant and non-compliant septic tanks that are at issue here, not pig farming. You will find a link to the full report at the bottom of the article.
Quickly detect pollution
During a week in November 2020, the Foundation team took 68 water samples going up the Loutre and Petite rivière Blanche rivers and then subjected them to bacterial analysis with a rapid water quality analysis device. the water that gives results in 15 minutes. As they detected peaks of contamination, the Fondation Rivières team traveled up the waterways and was able to identify exactly the sources of pollution in the two rivers. The Foundation team had to be resourceful in order to install the laboratory on the ground!
Doctoral student Rose Ragot from the National Institute of Scientific Research (INRS) accompanied us in the field and carried out analyzes of the mitochondrial DNA of the samples in order to establish the origin of the E. Coli. She also carried out traditional analyzes by enumeration, just to allow us to determine the precise quantity of E. Coli in water. Rose accompanied us because she needed, for her doctorate, to test a marker specific to pork pollution. Sad for her, but she didn't find one...
An unexpected main source
This study made it possible to detect peaks in fecal contamination in several locations, as well as their origin. And contrary to the initial hypothesis, this contamination came from a sewer network without a purification system, septic tanks and cattle breedings!
Indeed, around the municipality of Fugèreville, it was possible to follow the contamination gradient by taking samples further and further upstream of a tributary of the Rivière à la Loutre, to then arrive at the point of discharge of 'waste.
In addition, contamination associated with the presence of cattle farming was detected near six sampled sites: is it also spreading? Or do we let cows drink from streams? The question remains.
As for pig farms, although located near watercourses, they were only responsible for a single contamination peak out of the 68 samples. If pig slurry does not run off into rivers, this could perhaps be linked to the fact that Olymel injects the slurry into the ground instead of spreading it on the surface.
Take action
In Témiscamingue, we have already taken action. The OBVT raised awareness among local stakeholders and began to implement the main recommendations of the report:
- It is urgent that the municipality of Fougèreville equip itself with a wastewater purification system to prevent spills. like other regions of Quebec, but also that we learn about the locations of septic tanks along waterways.
- As far as cattle farms are concerned, it is high time to review spreading practices and the effectiveness of riparian strips near fields. Finally, we should check whether the animals are drinking where they should not.
All in all, these are unexpected conclusions which say a lot about the importance of good practices in wastewater management, but also in agricultural spreading techniques. So you shouldn't trust appearances!
