“Chicago’s new elaborate system of buoys and statistical models will monitor 16 of the city’s 24 beaches, and Park District officials are seeking grant money from the U.S. Environmental Protection Agency to expand the system to cover all beaches by next summer.

 

The model will predict the levels of harmful bacteria at each beach using data on the location of sources of contamination, like colonies of sea gulls or sewer outlets; the motion of waves that can disturb bacteria growing in the sand; lake-current speeds; water temperature; and sunlight.”