VERMONT STATE BEACHES
ANNUAL SUMMARY OF E. COLI
VIOLATIONS
State beaches are routinely
sampled by the Forests, Parks, and Recreation Department for E. coli every other week
throughout the summer. If the observed E. coli
concentration in a water sample is high, than the beach is resampled.
If resampling results in a high E. coli concentration, than the beach is
closed and resampled every day until counts again meet water quality
standards. This procedure
accounts for the variable number of observations among years. Although all samples are processed in the same laboratory, time of day
of sampling, weather conditions on sampling day, and the date of
sampling vary among beaches. Since conditions during sampling may
vary widely, direct comparisons of E. coli values among beaches is not valid.
At least two replicate samples are collected 300 feet apart at most
beaches on each sampling day. Since replicate water samples at a
beach are not averaged to determine beach closings, replicates have been
summarized as separate independent samples. Total percent
violations of the Vermont water quality standard for E. coli for class
B waters (77 organisms/100 ml) is summarized below. Total percent
violations for all Vermont state beaches range from a low of 2.4% in
1996 to 8.1% in 1998 which had a relatively wet summer.
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