Sampling Public Beach Water

Each year, we take samples of local beaches from June until the end of August to make sure the water is safe for people to swim in. Most beaches are sampled monthly, and few (beaches with a history of adverse sample results) are sampled weekly. 

Samples go to the Public Health Ontario Laboratory in Sudbury and Orillia to be tested for Escherichia coli (commonly known as E. coli), a sign that the water has been contaminated with fecal matter. It takes about 24 hours for us to receive and analyze the water quality results from the lab.

See below to learn about the status of your local public beach.

When is a Beach “Posted”?

If the level of E. coli in a sample set is more than 200 E. coli cfu/100mL, the beach will be re-sampled within 24 hours. 

If the level of E. coli in the re-sample set is more than 200 E. coli cfu/100mL, the water is considered unsafe for recreational use, including swimming.  

When a beach is unsafe, the “Unsafe for Swimming” sign (see below) will be posted to let beach visitors know about the high bacterial counts and potential threat to human health.

The sign is taken down when re-samples show levels of E. coli have returned to acceptable levels.

Between sampling periods, the beach water may have unsafe levels of bacteria due to:

• Heavy rainfall (the Rainfall Warning sign, below, is posted at all public beaches)
• Large numbers of waterfowl
• High winds or wave activity
• Large numbers of swimmers

When is a Beach “Closed”?

A beach is “closed” when a significant risk to human health and safety has been identified, such as signs of something in the water that could cause a hazard or infection.

Swimming in the water is NOT allowed when a beach is closed, and there will be little or no public access to the beach. A ‘Do Not Swim’ sign (see below) will be posted at the beach.

The beach is re-opened when there is no longer a risk to human health and safety.

Beach Status

Not Tested = For various reasons, such as a harmful algae bloom is present, high water levels and/or debris are in the area. 

For more information, please contact our Environmental Health Program at 1-800-563-2808, extension 5400 or by email at environmental.health@healthunit.ca.

Adapted with permission from Peterborough Public Health.