As the lakefront officially opens to swimmers Friday, the Lake Michigan shoreline joins the cutting edge in the war on bacteria after decades of using day-old water samples to decide whether to close beaches.
In Chicago, the Park District will use a new high-tech system that uses computer software to give real-time predictions of bacteria counts based on such factors as water temperature, modeling of the lake bottom and wave action monitored by buoys.
And Chicago beachgoers will almost certainly have more time in the water, as city officials announced that starting this year, they will close the beaches only when sewer overflows have contaminated the water. The rest of the time, they will post data for would-be swimmers, who can then decide to enter the water at their own risk.
Under the previous system, daily water samples were cultured for E. coli, which was considered a marker for other, more dangerous bacteria. When the results came back 18 hours later, officials would determine whether to close beaches based on data that was already a day old.
In Chicago, the Park District will use a new high-tech system that uses computer software to give real-time predictions of bacteria counts based on such factors as water temperature, modeling of the lake bottom and wave action monitored by buoys.
And Chicago beachgoers will almost certainly have more time in the water, as city officials announced that starting this year, they will close the beaches only when sewer overflows have contaminated the water. The rest of the time, they will post data for would-be swimmers, who can then decide to enter the water at their own risk.
Under the previous system, daily water samples were cultured for E. coli, which was considered a marker for other, more dangerous bacteria. When the results came back 18 hours later, officials would determine whether to close beaches based on data that was already a day old.
