It was a great summer to be a swimmer.
For the first time since Lambton Public Health began regular water testing, no Sarnia beaches had to be posted for high bacteria levels.
“We didn’t have any issues this summer,” said public health inspector Theresa Warren.
“We’ve always had some postings, and this was the first year that we’ve had zero.”
The water-testing program began in 2005 and sees seven Lake Huron beaches in Lambton County tested weekly for unsafe bacterial levels, including Bright’s Grove and Canatara in Sarnia.
Last summer, Canatara had a clean sheet as well but warning signs went up twice in Bright’s Grove.
Lambton Public Health tests for E. coli, a bacterium commonly found in the lower intestines of warm-blooded animals. It can cause vomiting and diarrhea if ingested.
E. coli is regarded as an “indicator bacteria” that settles in the soft sediment of the lakebed, Warren said. When levels get too high, beaches get posted.
Sewage runoff from farms and septic-related construction projects are the main culprit for bacterial runoff to the lake.
“A lot of our beaches are affected by weather, so we might not have had as many heavy rainfalls or high-wave activity (this summer),” she said.
Heavy rainfall and wave activity can send levels soaring for up to 48 hours. If the water is cloudy enough that a swimmer can’t see his or her feet in waist-deep water then harmful bacteria may be present, she said.
“When we take our sampling we’re just taking a snapshot. We’ve found that the water quality can change daily, and even hourly, so that’s why we always keep the warning signs at beaches.”
The St. Clair River is not tested, so permanent signs warning of bacteria are placed at Seager, Branton Cundick and Brander parks.
The water-testing program will resume next June.