Why are the beaches monitored by the McHenry County Department of Health?
To protect the public’s health, the Department requires that each of the licensed public beaches in Illinois be sampled every two weeks on a routine basis. Beach water samples are collected in the shallow and deep areas and are sent to a Department laboratory for analysis. If the results exceed the Department’s limits, the risk of illness increases and the beach is required to be closed. When will the beach re-open? Factors such as natural die-off, wind and wave action, and ultraviolet light from the sun will help to reduce the level of bacteria. The length of time this takes is unpredictable; however, it is usually less than 24 hours. The water needs to be re-sampled and the samples from both the shallow and deep areas must be below 235 cfu of E. coli/100 ml. before the beach will be allowed to re-open. It takes 24 hours after receipt of the samples to determine the bacteria levels. How does the bacteria get in the water? There are a variety of sources that contribute bacteria to surf
