Beach Water Quality

beach-signThe quality of Lake Huron water can change dramatically day to day, hour to hour, or even minute to minute with either heavy rainfall, high wave action, or both. The Huron County Health Unit encourages recreational users of Lake Huron to read the signs to reduce health risks.

The health unit regularly samples 14 public lake shore beaches during June, July, and August. At least five water samples are collected at each beach and are sent to an Ontario Public Health Laboratory for bacterial analysis. This determines the number of E. coli colonies present in the sample. E. coli in the water indicates the potential presence of disease causing organisms, such as bacteria and viruses. The lab results are posted on our website weekly.

Recent E. coli levels for each beach 

The sources of E. coli include, among others, animals and waterfowl, swimmers, and malfunctioning sewage disposal systems. The number of E. coli can be influenced by rainfall, turbidity (water clarity), air and water temperature, as well as the shape of the coast line.

The higher the number of E. coli colony above 100, the higher the risk of becoming ill when swimming in that water.

It takes about 24 hours to receive the previous day water testing results from the laboratory (E.coli takes 18-24 hours to incubate and culture). By then the water may have changed to either safe or unsafe for swimming.

Ask yourself these questions to decide if it’s safe to swim:

  1. Is the water turbid (can’t see my feet while standing waist deep in water)?
  2. Has there been heavy rainfall in Huron County in the last 24 to 48 hours?

If you answered yes to either of these questions, E. coli levels are probably high and it may be unsafe to swim. The current E.coli test is only an indicator that there was fecal contamination from either animal, human, or both, and that there could have been other harmful bacteria, parasites and viruses present in the water when the samples were collected.

To help the public determine if it is safe to swim, all of the Huron County public swimming locations have been posted with a sign providing the Health Unit’s telephone Infoline and a QR code. The Beach Water Infoline is updated regularly throughout the summer months.

NOTE: The Health Unit only samples lake water at a number of public beaches along the Lake Huron shoreline. We do not test other bodies of water (rivers, ravines, gullies, dams) that may be used for recreational purposes and therefore have no information on these sites’ water quality. Residents should be aware these areas could be unsafe for swimming.

There are a number of initiatives underway in Huron County to improve water quality at the beaches and throughout the watershed.  One of those projects involves monitoring stormwater outfalls at the Bayfield Main Beach.  This project is organized by the Bluewater Beach Committee whose members include Pioneer Park, Municipality of Bluewater, Ausable Bayfield Conservation Authority, and Huron County Health Unit.  The most recent water test results can be found on the Bayfield Beach Stormwater Monitoring web page.  Reports from previous years can be found on the Ausable Bayfield Conservation Authority Water Quality web page.


If you have a question please call us at 519.482.3416 or toll-free at 1.877.837.6143. Ask to speak to a public health inspector on the Environmental Health team. Or email beaches@huroncounty.ca.