Beaches are monitored from Memorial Day through Labor Day.
From May to September, the Health Department's Lakes Management Unit samples Lake Michigan beaches 4 days a week. Beaches on inland lakes are tested bi-weekly. 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 after a large rain event.
NOTE: Per Illinois Swimming Code, there is no swimming at dog beaches.
||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.
(Beach advisory information will be updated daily by 10 am, Memorial Day through Labor Day)
To view historical data: http://app.idph.state.il.us/envhealth/ilbeaches/public/Default.aspx
National Weather Service Beach Hazards (check for high wave/rip current warnings):
June 30, 2015
INLAND LAKE BEACHES (closed)
Cedar Lake - Cedar Lake Park Beach
Grass Lake - Grass Lake Marina
Round Lake - Bengson Park Beach
Valley Lake - Valley Lake South Beach
INLAND LAKE BEACHES (advisory):
Petite Lake - Petite Lake Highwoods Beach