All About E. Coli
GLEA provides weekly E. coli testing as a public service but cannot guarantee real-time water safety.  Results each week are a snapshot of water quality, as bacteria levels can shift quickly. It is important to remember the decision on whether to swim is at your own discretion. Use caution, especially with young children or individuals with weakened immune systems.
Weekly Process
GLEA monitors E. coli bacteria levels at public beaches around Geneva Lake by collecting water samples every Monday during the summer. These levels help indicate the potential presence of harmful germs. Results are shared with local municipalities and posted on GLEA’s Facebook, Instagram, and website page (www.gleawi.org) within 24 hours. While these tests provide a helpful snapshot of water quality, conditions can change quickly due to weather, wildlife, runoff, or wave activity. One area may test clear, while another nearby area may contain higher levels of bacteria. GLEA posts counts taken from 1–3 sample points at each beach location. If levels are high, GLEA retests until levels are within EPA standards and continues to post updates to the public.
Please remember, even when results fall within safe limits, water and bacteria are continuously moving. An E. coli level of 0 is the safest possible reading. Always swim with caution - especially children who are more vulnerable to exposure.
Recommended Safety Tips:
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Avoid swallowing water.
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Shower after swimming.
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Don’t swim with open wounds or recent illness.
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Wash hands before eating if they’ve been in contact with lake water.
Beach Safety Signs (Updated Every Tuesday Based On Testing):
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Green (0-235) = No advisory in place.
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Yellow (235-999) = Advisory in effect: swim with caution, especially for children or immunocompromised individuals.
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Red (1,000 and above) = Beach closed: unsafe levels detected (per DNR guidelines - Wisconsin Department of Natural Resources)
Last Posted Levels
