As if downed trees and flooded viaducts aren't enough, Monday night's severe storms have derailed swimming at Chicago's 27 beaches today, as well as in some North Shore communities.
The heavy rains required opening the locks in both Chicago and Wilmette, releasing waste water into Lake Michigan. As a precaution, the city put a swimming ban in effect, said Cathy Breitenbach, director of cultural and natural resources for Chicago Park District.
However, the beaches remain open in Chicago. "You just can't go in the water," said Breitenbach, pointing out that if you really want to work on that butterfly stroke, the city has one inland lake in Humboldt Park — which is unaffected by the release of waste water — along with 77 pools.
Swimming was also prohibited in Evanston following the opening of the locks, said Carl Caneva, assistant public health director. "Whenever that happens, the beaches are closed for 24 hours."
From May to September, lakefront communities typically test water samples on a daily basis for E. coli bacteria, which are found in the intestines of almost all warm-blooded animals, such as dogs. If water samples come back high for E. coli (235 E. coli/100 ml), the city is notified and a sign is posted indicating the closure, according to Lake County Health Department's Lake Management Unit.
Additionally, since heavy rains tend to lead to elevated bacteria levels, many public health officials advise avoiding swimming after a heavy storm.
Water quality testing is done on a daily basis, so it's too early to know how July 4th plans will be affected, said Caneva. "We're very much day to day."