News Release 331

Swimming beach at Mark Twain State Park to remain closed for weekend

Volume 38-331 (For Immediate Release)
Contact:  Judd Slivka

JEFFERSON CITY, MO, JUNE 3, 2010 – The public beach at Mark Twain State Park will remain closed this weekend because of E. coli levels that remain higher than the standard set by the Missouri Department of Natural Resources for state park beaches.

Mark Twain State Park Beach will remain closed because the results from water samples drawn Tuesday, when combined with results from previous weeks, showed E. coli levels in excess of the department’s standard.

When combined with samples taken the two previous weeks, the water at the park’s public beach had a geometric mean of 370.1 E. coli colonies per 100 milliliters of water.  

In order to provide a safer beach experience, the Department of Natural Resources will close beaches at state parks if the geometric mean for E. coli, which considers previous results in addition to the current week’s results, exceeds 126 mpn/100 mL. The department will also close a state park beach if the E. coli level is above 235 mpn/100mL, which is also the U.S. Environmental Protection Agency’s single-sample guideline for a swimming beach.

The public use beach at Mark Twain State Park has been posted with signs notifying visitors of its closure. The park’s group camp beach met the department standard and remains open. The 2,775-acre park is located in Monroe County in northeast Missouri along the 18,000-acre Mark Twain Lake.

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 information about all temporary closings at state parks is available online at /asp/spbeaches/state-park-beach-status.asp.

The Missouri Department of Natural Resources, through its Division of State Park, 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.