News Release 374

No State Park beaches closed due to elevated E. coli levels this weekend

Volume 38-374 (For Immediate Release)
Contact: Judd Slivka
573-751-1010 (after hours)

JEFFERSON CITY, MO, JUNE 23, 2010 – No Missouri State Parks swimming beaches will be closed due to elevated E. coli levels this weekend.

The public beach at Mark Twain State Park will remain closed due to high water. Samples drawn Monday from the beach were under the EPA’s recommended single-sample maximum of 235 E. coli colonies per 100 milliliters of water. However, those samples, when combined with results from previous weeks, continue to keep the park in excess of the department’s geometric mean standard for E. coli at state park beaches.  A geometric mean takes into consideration the results of the previous samples drawn from the same beach.

Samples drawn from state park beaches are only relevant to those beaches and do not indicate overall water quality in a large body of water.   

In order to provide a safer beach experience, the Department of Natural Resources will close a state park beach if that beach’s geometric mean for E. coli exceeds 126 E. coli colonies per 100 milliliters of water. The department will also close a state park beach if a single sample is above 235 E. coli colonies per 100 milliliters of water, which is also the U.S. Environmental Protection Agency’s single-sample guideline for a swimming beach.

The beach at Mark Twain has been posted with signs notifying visitors of the closure and will remain closed until E. coli levels – and, in the case of Mark Twain State Park, the overall water level – meet the department standard.

No other state park beaches tested high for E. coli levels; however, bacterial levels often rise after heavy rains and lake users should use their judgment when swimming after heavy rains.

The latest information on beach closings at state parks is available online at /asp/spbeaches/state-park-beach-status.asp. Additional beaches may be closed for other reasons, such as high water levels or safety and management issues. Information about all temporary closings at state parks is available online at /asp/spbeaches/state-park-beach-status.asp. Sampling results for the U.S. Army Corps of Engineers beaches at Mark Twain Lake have been added to the map this week.

The 2,775-acre Mark Twain State Park is located in Monroe County in northeast Missouri along the 18,000-acre Mark Twain Lake.

The Missouri Department of Natural Resources, through its Division of State Parks, manages 85 state parks and historic sites throughout the state, including 15 with swimming beaches. Water samples are taken weekly during the recreational swimming season to help ensure a safe public swimming area.

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 strains can cause gastrointestinal illness. 

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.