Overview

• Several popular urban beaches, including Toronto’s Centre Island, Ottawa’s Mooney’s Bay and Windsor–Essex County sites, were flagged unsafe after water samples detected elevated E. coli levels.
• Toronto Public Health’s daily sampling applies a stricter limit of 100 CFU per 100 mL, prompting earlier no-swim notices compared with the provincial standard.
• Ottawa Public Health switched to weekly testing under the province’s 200 CFU threshold, resulting in advisories at Mooney’s Bay and Petrie East Bay after recent tests exceeded safe levels.
• Health experts recommend avoiding swimming for 24 to 48 hours following heavy rainfall to reduce exposure to bacteria washed into recreational waters.
• Weekly monitoring of five Rideau River locations by Carleton University researcher Banu Örmeci found all sites currently meet safety criteria, bolstering calls for more supervised river beaches.