Water quality in the Richelieu and Yamaska rivers, 2020
Contamination by toxic substances
Status: Poor for 2014-2019
Trend: Unchanged since 2001-2003
Status: Over the 2014-2019 span of time, the general quality of the waters of the Richelieu River measured at the city of Sorel-Tracy, and the Yamaska River measured at the city of Saint-Hyacinthe, was poor. Median concentrations of PCBs and, in particular, the very high levels of PCDD/Fs in toxic equivalent, exceeded established criteria for the protection of fish-eating terrestrial wildlife.
Evolution: Concentrations of penta-BDE in the Richelieu for 2014-2019 dropped significantly, while in the Yamaska, concentrations of PCBs and penta BDE were lower than in the preceding period. No significant changes were observed for the other indicators.