Recreational water illnesses (RWIs) can spread if you swallow, have contact with, or breathe in mists or aerosols from water contaminated with germs. You can also get them by having contact with chemicals that are in the water or that evaporate from the water and turn into gas in the air. Diarrhea is the most common RWI. 

The Lake County Health Department monitors lake water for E.coli bacteria in over 100 Lake Michigan and inland lake beaches to ensure that the water is acceptable for swimming. From Memorial Day to Labor Day, beach closure information can be found through the interactive map on the Health Department’s Beach Monitoring and Advisories web page, which is updated daily by 10:00 a.m.   

When bacteria levels are high, the Health Department notifies the beach’s manager, and signs are posted indicating a swim ban is in place. Water samples are taken daily until the bacteria levels fall below the standard.  

“Recreational water illnesses can not only hamper your summer plans, but they can also get others sick,” said Alana Bartolai, Ecological Services Program Coordinator. “We monitor the water quality to ensure that individuals and families can enjoy the many beautiful lakes and beaches in Lake County to their fullest.” 

Here are ways to protect yourself from illness at pools and water parks:  

• Don’t swim or let your children swim when sick with diarrhea.   

• Don’t swallow the water.   

• Take children on bathroom breaks every 60 minutes.  

• Check diapers every 30–60 minutes and change them in a bathroom or diaper-changing area—not waterside—to keep germs away from the water.  

• Shower before you enter the water. 

• Never swim alone. 

Follow these tips to avoid hazards when swimming in our lakes this summer:  

• Before heading to your favorite lake, check if the beach is open on the Health Department website. If a swim ban is in place, do not swim in the lake.  

• Avoid swimming in lakes after a large rain event, since rainfall can wash pollutants into lakes resulting in elevated bacteria levels.  

• On Lake Michigan, don’t swim during times of heavy surf (i.e., high waves), which can overpower even the strongest swimmer. Know before you go and check the National Weather Service for any beach hazard advisories and never swim alone. 

• On inland lakes, occasional harmful algae blooms may occur. Avoid areas where the water has a green or blue-green appearance. Report any algae blooms to the Health Department.  

Throughout the summer, the Health Department samples 11 beaches along Lake Michigan four days per week:  

• North Point Marina Beach, Winthrop Harbor  

• Illinois Beach State Park North Beach, Zion  

• Illinois Beach State Park South Beach, Zion  

• Illinois Beach State Park Resort Beach, Zion  

• Waukegan North Beach, Waukegan  

• Waukegan South Beach, Waukegan  

• Foss Park Beach, North Chicago 

• Lake Bluff Sunrise Beach, Lake Bluff  

• Forest Park Beach, Lake Forest  

• Park Avenue Beach, Highland Park  

• Rosewood Beach, Highland Park  

The Health Department also samples Lake Bluff Dog Beach and Moraine Dog Beach once a week.   

For more information on beach monitoring, please call Lake County Health Department’s Environmental Services at (847) 377-8020.