From May to September, the Health Department's Lakes Management Unit samples Lake Michigan beaches 4 days a week. The water samples are tested for E. coli bacteria, which are found in the intestines of almost all warm-blooded animals. While not all strains of E. coli are the same, certain strains can make humans sick if ingested in high enough concentrations.
If water samples come back high for E. coli (235 E. coli/100 ml), the management body for the bathing beach is notified and a sign is posted indicating the beach closure. Additionally, since rain events tend to lead to elevated bacteria levels in the water column, the LMU advises that persons avoid swimming for 48 hours after a large rain event.

Low Bacteria Levels, No Advisory

Elevated Bacteria Levels, Caution Swimming Advisory

High Bacteria Levels, No Swimming is Advised
Click on the name of the beach to view it individually on a map. A map of all the beaches is included below.
Labor Day Weekend, September 4-7, 2009
(Beach advisory information will be updated daily by 10am, Memorial Day through Labor Day)