None of the water samples drawn from the Lake of the Ozarks on Monday, Aug. 2, had E. coli levels in excess of federal standards for public swimming beaches, the Missouri Department of Natural Resources announced Wednesday, Aug. 4.
The department sampled 51 sites primarily along the lake’s Gravois Arm for E. coli bacteria. The purpose of the program is to develop a five-year baseline that will assist in future studies of the lake’s health.
These coves were tested in June and will be tested again in October. The department will test a different set of sites along the Osage Arm from Mile Marker 36 to Mile Marker 60 in September. Testing, which began in June, will continue through October with each set of coves being tested three times.
The U.S. Environmental Protection Agency has established a single-sample recommended maximum level of 235 E. coli colonies per 100 milliliters of water for public swimming beaches. The highest E. coli level found in the August sampling was 39.3 colonies per 100 milliliters.
E. coli is a bacteria found in the intestinal tract of warm-blooded animals, including humans. While most strains of E. coli are harmless, some can cause gastrointestinal illness. The testing process used in this study does not differentiate between strains.
These bacteria and other pathogens can reach lake water from many different sources, both human and animal. For some people, such as children, elderly or those with weakened immune systems, even low levels of these bacteria may cause illness.
The sampling program is the result of a partnership between the Department of Natural Resources, Ameren UE and the Lake of the Ozarks Watershed Alliance, which provides trained volunteers to collect the samples. Ameren also pays $15,000 per year for the five-year study. When completed, the water testing will include coves from Bagnell Dam to Truman Dam.
A link to the results and a map of the areas to be sampled is available on the department’s website at dnr.mo.gov/loz.htm. Monitoring results will be posted to the map as they become available.
