I get this question every year: “is Lake Ontario safe to swim in? I read in the paper that some beaches were closed?!”
Swimming and bacteria is all about odds… like many things in life. Could you get some type of bacterial infection… sure… but we’ve chosen the area where we swim because the odds of that are low.
Bacteria levels are always an issue in any lake, river or ocean (even pools for that matter!). However some bodies of water, and certain areas of those bodies of water, are more prone to bacteria than others, especially later in the summer when things warm up.
Lake Ontario is the 11th largest lake in the world, so obviously conditions change from one area of the Lake to anther area of the lake. Areas that are shallow, warm, protected and don’t circulate well are more prone to having e-coli, bacteria and other contaminants. These are the areas that often seem nice to swim in… shallow, warm areas in protected bays… but they are often the ones you read about in the paper that are closed for swimming.
However there are other areas that are fine to swim in. Fortunately we have chosen an area where the conditions are usually very good.
Were we swim the shore line is quite open and not in a bay and therefore circulates well. We all know that we also have one of the coldest areas of the Lake!… and that’s a good thing! Right off shore from where we swim is one of the deepest areas of the Lake, which keeps it cool and helps it circulate. So we rarely have an issue with contaminants that other areas of the lake often have. This is one of the main reasons we swim where we swim… also there is virtually no boat traffic, which also makes it a safe place to swim!
There are certainly areas in the Lake that I wouldn’t swim at this time of year, when the weather is hot and there has been a lot of run off… and there are certainly local Lakes where I wouldn’t be swimming in at this time of the year either (Gulliver’s and Kelso, for example… ask Darren, Joanne, Denise, etc)… but I feel very comfortable swimming
where we swim. In the 8 years that we’ve swum here, (and we’ve had plenty of rain and hot weather over that time), we have virtually never had anyone get so much as an ear infection from the water!
Hey, I wouldn’t be swimming in the Lake if I thought there was an usual risk from bacteria!
PS. Part of the beauty of LOST swimming is we have so many members, and there is often someone more knowledgable than me on any given topic! I just recieved this from a LOSTie who works in the water industry in Toronto… and here’s what he said…
“… Cherry Beach is nearby our facility and we monitor the water very closely and take preventive measures for E.coli at 10 mm, the storm dropped 126 mm.
Any time there is rain ie 5 mm or more I would not swim at Cherry Beach for at least 24 hours as we have learned it takes that time frame for the E.coli level to return to normal. Cherry Beach is Blue Flag beach and the only one I would consider swimming at in Toronto. (24 hours after any rainfall)
At the LOST swim area there is no nearby sewage plants, or agriculture run off. The creek flows very fast post rain and into the deep area, plus there is no sand at the beach front which is another E.coli storage area. Most E.coli are in the shoreline area of 5 meters and 1 meter depth.
The single biggest difference in swim areas is that in Oakville I am not aware of any combine sewer systems because of practices from decades gone by they have sanitary sewers and storm sewers locate beside each other. With each in a half of a pipe, once it rained sufficiently and in the case of around Cherry beach at 10 mm the storm sewer fills and then flood the sanitary pipe which causes raw sewage to be discharged into the lake. The e.coli levels increase depending on how much rain falls to cause the flooding of storm sewer pipe to continue and duration of overall rainfall period.
Cherry Beach also has the Don River discharging nearby and the transport of E.coli post rain is a very big influence. Also the Cherry Beach basin is very shallow.”
See you tomorrow!
Cheers,
Rob