When the geometric mean for E. coli exceeds 126 colonies per 100 mm of water, signs will be posted on the beach advising children, the elderly, and those in poor health not to swim, Binns says. Water quality has improved steadily over the years in Lake Erie, with some fluctuations from year to year. But bacteria counts can be affected by fairly random events. Counts were high throughout 1996, and Ohio beaches were posted with warning signs throughout the summer. Later, tests revealed an unusual amount of goose droppings in the lake, Binns recalls.
Caution continues to be a rule of thumb.
One safe bet is to stay away from swimming in the lake for 24 hours after a heavy rain. The bacteria counts always go up. All rights reserved. All rights reserved.