The City of Nelson has posted signs at Lakeside Park advising against swimming.
Every week, Nelson’s public works department tests the water at Lakeside Park. For each 100 ml sample, the acceptable limit is 200 counts of E. coli, averaged over five different samples, with no sample higher than 400.
This week, the count was 1,100.
“We don’t remember seeing a sample that high in the past,” said Colin Innes, the city’s public works director. “For us this is a rare thing.”
Innes says he thinks the culprit is goose feces, but he isn’t sure.
“That is just us making an assumption. There could be other sources. Sewage could get into this lake, and there is an awful lot of lake and a lot of homes out there.”
Escherichia coli, usually called E. coli, refers to a large group of bacteria that is commonly found in the intestines of humans and animals, according to the Public Health Agency of Canada.
“Most strains of E. coli are harmless,” the agency’s website states, “however, some strains … can make people sick, causing severe stomach cramps, diarrhea and vomiting. Serious complications of an E. coli O157:H7 infection can include kidney failure.”
Innes said the city will test the water again on Friday.
“Because it is a natural body of water, the quality throughout it will vary. We are kind of at the mercy of what the water brings us,” Innes said.
He said if the problem continues, “we will start looking for potential sources of sewage and conduct some additional testing to see if we can identify a source of contamination.”
Bill Metcalfe photo