June 29, 2017 - This summer the TBDHU will be putting up new permanent swimming advisory signs at Boulevard Lake and Chippewa Park beaches advising the public of the potential risk of E. coli in the water. The signs will indicate the likelihood that the water has elevated levels of E. coli, based on five years of previous water quality tests. The new signs are intended to help the public make decisions about the risk of harm to their health due to E. coli at any time they are considering a swim.
This is a change from prior years when temporary signs advising people not to swim would be posted if a current water quality test indicated elevated levels of E. coli. The sign would then be removed if test results improved. However, the TBDHU explains that the presence of the temporary signs - or the lack of them - may be providing the public with a false sense of security.
“The temporary advisory signs reflected a snapshot of E. coli levels at the time the sample was taken, but water quality can change rapidly,” says Lee Sieswerda, manager of environmental health at TBDHU.
“Water quality can change due to wind, waves, weather, and waterfowl over the course of a few hours. However, it takes one to two days to take the water samples, test them for E. coli, and then post the advisory signs, so that ‘snapshot’ is no longer an accurate indicator of current conditions. Therefore, we will no longer be advising people whether or not to swim based on short-term E. coli tests. Instead, we will provide people with a long-term summary of E. coli test results over the past five years. People can use that information to decide if they want to swim at that beach.”
For example, at the Boulevard Lake Main Beach, 64 water quality tests have been conducted over the past five summers and 20 showed elevated levels of E. coli. This means that approximately 30% of the time, Boulevard Lake Main Beach had elevated levels of E. coli. This will be the number reflected on the new signage at Boulevard Lake. Similar signage will be posted at Chippewa Main and Sandy Beaches.
The Health Unit will continue to take water samples at all beaches listed on the TBDHU.COM website. The information collected from testing results will be analyzed at the end of the season in order to update the message on the permanent signs for 2018 if necessary.
These new signs will not be used for beaches outside of Thunder Bay because these beaches rarely have elevated levels of E.coli. For these beaches, temporary advisory signs will continue to be posted/taken down when appropriate, based on E. coli test results.
Swimming in water with elevated levels of E. coli can cause skin, eye, nose and throat infections, as well as stomach illness. To reduce their risk, swimmers should be advised to:
- avoid swallowing beach water
- towel off after a swim
- shower once at home
A more detailed explanation of the new signs, along with photos, can be found on the Health Unit’s website at TBDHU.COM