Lake Ontario Waterkeeper

Toronto Community Monitoring Hub


Source Information

Swim Drink Fish staff, interns, and volunteers monitor recreational water quality in the Toronto Harbour during the summer months. The guidelines followed are the 2014 Ontario’s Provincial Water Quality Objectives, set by the Ministry of Environment at 100 E.coli per 100 millilitres of water.

Water is sampled for E. coli and Total Coliform at all sites. The water is sampled twice a week, on Tuesdays and Thursdays from the end of May to early September. Results are available 24 hours after samples are collected, on Wednesday and Friday afternoons. Beaches are posted when the geometric mean of 5 samples collected within a given swimming area and within a 30-day period exceeds 100 E. coli / 100 ml of water.

A The Ministry of the Environment F-5-5 procedure says that a clean beach must meet water quality criteria for at least 95% of the swimming season, even if it is near a sewage pipe or combined sewer outfall. Test results are expressed as Most Probable Number (MPN) of E.coli per 100 ml by using the IDEXX Quanti-Tray/2000 MPN Table. 

A beach is marked Green when the geometric mean of 5 sample results are equal or below 100 E.coli / 100 ML water. 

A beach is marked Red when the geometric mean of 5 sample results are above 100 E.coli / 100 ML water. 

A beach is marked Grey when there are no current results or there is no available information. 

Results are posted as soon as lab results are available. Results will be communicated through the swim guide website and apps. To see a full sample results tables visit the website. Results are also available by email at or by calling The Swim Guide +1 (416) 861-1237.