Beachgoers in Evanston who had planned to cool off in the waters of Lake Michigan last Friday were forced to alter their plans after the beaches were deemed unsafe for swimming.
The North Shore beaches were closed June 20 after tests showed high levels of bacteria in the water.
Bacteria in the water can cause nausea and rashes. However, Jay Terry, director of the city’s health and human services department, said there have been no major cases of bacteria-related problems with swimmers.
According to the Web site for the Lake Michigan Federation, the bacteria, primarily E. coli, comes from raw sewage.
Beaches are tested daily, and when the bacteria count exceeds the safe threshold, anything more than 1,000 parts per 100 milliliters, the water is closed to swimmers.
However, closings are dependent on samples taken the previous day because constant water flow can either increase or decrease the amount of bacteria in the water.
Test samples from the lake are brought into the Evanston Health Department every morning for review. The results, which take 24 hours to process, determine whether or not the beaches will be open the following day.
While the beaches are closed, they are not subject to any special treatments for the high bacteria count because only the water flow can lower the bacteria count to levels safe for swimming, Terry said.
He also said there currently is no clear way to predict when the beaches will need to be closed.
“One of the goals is to see if there is any way of predicting when a beach will close because of high bacteria counts,” Terry said.
But for some swimmers and beachgoers, the unpredictability of the tests and closings is troubling.
Chicago resident Connie Marchwiany said she comes to Evanston beaches because they are cleaner and less crowded but expects more to be done about the unsafe waters.
“I know (closings) happen a lot and I am bothered by that,” Marchwiany said.
But closings cannot be prevented, Terry said. Though animal and human waste both contribute to the bacteria problem, it is difficult to pinpoint a direct cause of the problem.
“Everybody has their own theory about what exactly causes this bacteria,” Terry said.
He added that more testing may lead to better understanding of the exact cause and to possible solutions.
This year, the city of Evanston tests the water in the neighboring villages of Wilmette and Winnetka, in addition to Evanston’s five public beaches. Evanston received state funding to test all the North Shore beaches to ensure that consistent testing procedures were being used, Terry said.
Despite these stringent testing measures, Marchwiany said she is still uncomfortable with the idea that the bacteria problem is not directly addressed.
“There’s not a lot of difference between safe and just below safe,” Marchwiany said. “They need stricter rules and better testing.”
The beaches are expected to be open until July 31, but daily testing will be the final determinant. Swimmers can check the status of local beaches by going to www.cityofevanston.org or by calling (847)492-7082.
The Summer Northwestern’s Malavika Jagannathan contributed to this report.