Recreational Water Quality

The water at your local swimming area may look clean, but is it?

Rivers, ponds, lakes, and streams may contain disease-causing microorganisms. Swimming in contaminated water may result in minor skin rashes, sore throats, diarrhea, or more serious problems like gastroenteritis, an inflammation of the lining of the stomach and intestines.

Children tend to spend more time in the water than adults and may be more likely to swallow water when swimming. For this reason, they are more likely than adults to get sick if the water is contaminated. Infants, the elderly, and people with weakened immune systems have the greatest chance of becoming seriously ill.

How often should swimming water be tested?

The swimming water at Vermont municipal beaches and other publicly used, recreational areas should be tested at least once a week from Memorial Day to Labor Day. Additional testing may be warranted after floods or periods of heavy rain when swimming areas are more vulnerable to runoff contamination.

People who have a pond or swimming hole on their property should test for water quality periodically throughout the summer months.

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What is swimming water tested for?

Water in ponds, lakes and rivers is tested for coliform bacteria, especially Escherichia coli, commonly known as E. coli., to determine whether it is suitable for swimming. E. coli is a bacterium that is almost always associated with human or animal feces. Its presence in water means that other disease-causing microorganisms may be present as well.
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When should water samples be taken?

Water samples should be taken at times and locations of greatest bather use. Once the sample is taken, deliver or mail it to the laboratory as soon as possible. If you mail the sample, use either first class or overnight delivery because testing is recommended within 30 hours of sample collection.

Sampling early in the week leaves time to take follow-up samples before the weekend if results show contamination. Normally, at the Vermont Department of Health Laboratory, the results of samples submitted on Friday will not be available until the following Monday unless special arrangements are made. (Details on test kits, prices, lab schedules)

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Where should water samples be taken?

Water samples should be taken in an area where the water is at least 2 feet deep. This typically means that the person taking the samples must wade out to a point where the water is between knee and waist deep, and then dip the sampling container into the water. At this point, follow the instructions that are included with the test kit.

What does the E. coli test result mean?

E. coli in water is measured as the number of organisms found in 100 milliliters (ml) of water. When the test result at a public swimming area is 77 or less, it means that the water is considered suitable for swimming. A result greater than 77 means that the water is not suitable for swimming. (See Fact Sheet on E. coli)
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When should the swimming area be closed?

If the test result is greater than 77, the swimming area should be closed immediately. The beach area should remain closed until another test result shows that the E. coli level is 77 or below.

Follow-up test samples should be taken at the same location as the initial sample to provide the meaningful test results.


Where can I get more information?

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