Why Are Beaches Posted?
Beaches are posted with warning signs because the water may contain high levels of bacteria. High levels of bacteria can increase a swimmer’s risk of developing skin, eye, ear, nose and infections or irritation and possible stomach illness.
What Are the Guidelines for Posting Beaches?
Ontario beaches are posted with warnings of possible health risks when elevated Escherichia coli (E. coli) levels are present based on the results of five samples taken across the beach. The current E. coli test is an indicator that fecal contamination was present at the time of sampling.
The water is safe most of the time; however caution must always be taken when swimming in any natural water source.
What Affects Surface Water Quality?
Surface water quality continuously changes as it is open to the environment. The following conditions may affect surface water quality:
- Elevated levels of E.coli often occur after heavy rainfall because of surface water runoff.
- Fecal material from birds, pets and wildlife.
- Dirty water from storm sewers and the streets that washes into the river or lake after a rain storm.
- Faulty or overwork septic systems, agricultural runoff and sewage treatment plant bypasses.
- Blue-green Algae blooms resulting from high nutrient levels.
Should You Swim?
You should not swim if the beach water is cloudy due to high winds causing waves or following a heavy rainfall. Cloudy water can be an indication of high levels of bacteria which may pose a health and safety risk as you may be unable to see what is in the water. Shallow, sheltered and warm water may also contain high levels of bacteria. If there are a high number of birds such as geese or bird poop on the beach we would recommend not swimming as often time the poop from the birds will contaminate the water.
From time to time a swimmer may get irritated skin from swimming in local lakes and rivers; this irritation is commonly known as swimmer’s itch. Swimmer’s itch is caused when microscopic parasites from infected birds, snails or animal gets into the local water body through their feces. When the parasites come into contact with a swimmer, the parasite will burrow into the swimmer’s skin causing an allergic reaction and rash. The Health Unit does not specifically test for these parasites but conditions to look for at the beach are large number of shore birds and snails in the water. More information about swimmer’s itch.