JEFFERSON CITY, MO, JULY 1, 2008 -- This summer's second round of water testing at the Lake of the Ozarks found five cases in which samples taken showed E. coli bacteria in excess of the standard commonly used for swimming and other whole body contact recreation, according to the Missouri Department of Natural Resources.
A total of five samples out of 53 samples taken were found with E. coli present in levels in excess of the standard. The samples, the second of six monthly samplings scheduled for the Lake of the Ozarks, were taken June 16 at sites between the Lake of the Ozarks Community Toll Bridge and mile marker 30.
The highest level of E. coli was found in a sample taken from Cove 048, which is located near mile marker 26, Osage Beach. That sample showed E. coli present at levels of 1553.1 colonies per 100 milliliters -- the highest level recorded during this year's testing program and more than 12 times the state standard for swimming and other aquatic recreation. Two other samples taken in the same cove showed E. coli present at 435.2 and 186 colonies per 100 milliliters, respectively.
The state water quality standard for water bodies with whole body contact for recreation is a geometric mean of 126 E. coli colonies per 100 milliliters of water during the recreational season of April 1 to Oct. 31. The geometric mean is a statistical method used to combine the data that reduces the effect of extremely high and low values that can bias the results. The U.S. Environmental Protection Agency's suggested maximum level for a single sample taken at a beach is 235 E. coli colonies per 100 milliliters of water. For more information concerning possible health effects, contact the local county health department.
E. coli levels of 201.4 colonies per 100 milliliters were found in a sample taken at Salt Hollow, located near mile marker 21, Osage Beach. A sample taken at Woods Hollow, located near mile marker 22.5, Osage Beach, showed levels of 191.8 colonies per 100 milliliters. Both of the other samples taken from Salt Hollow were relatively high but within the standard. One of the two other samples taken at Woods Hollow was also near, but not above, the standard.
The Department of Natural Resources' Southwest Regional Office will be investigating those coves where the higher E. coli levels were found to determine possible causes.
Between now and October, the Department of Natural Resources, in partnership with the Department of Conservation, Ameren UE and the Lake of the Ozarks Watershed Alliance, will test coves from the Community Toll Bridge to mile marker 30. Alliance volunteers trained to do such sampling are doubling the number of sites that can be sampled.
This is the second year of testing for the Lake of the Ozarks. Ameren is paying $15,000 per year for the five-year study. When completed, the water testing will include coves from Bagnell Dam to Truman Dam.
E. coli is a bacteria found in the intestinal tract of warm-blooded animals. Frequently associated with faulty septic tanks or sewer systems, E. coli can cause gastrointestinal illness. For more information on E. coli and the testing program, including 2007 results, visit the department's Web site at http://www.dnr.mo.gov/pubs/pub2239.pdf
Water sample test result data are online at www.lmvp.org/LOWA/ecoli.htm. A link to the data can also be accessed through Lake of the Ozarks Watershed Alliance's Web site, www.soslowa.org.
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