Bathing Beach Water Quality
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Barnstable County has been monitoring Cape Cod’s beaches for over 30 years. In 2002, our efforts were formalized and expanded as the result of amendments to the Clean Water Act that were passed to improve the quality of coastal recreational waters. To date, Barnstable County receives funding from the United States Environmental Protection Agency through the Massachusetts Department of Public Health to conduct sampling and bacteriological analyses of public marine beach water. In addition, the program is offered to semi-public beach operators (residential homeowner’s associations and hotels/motels) for a low per-sample cost.
Over the past 13 years, the beach sampling program has been vital to protecting public health on Cape Cod. We sample and analyze over 350 marine and freshwater beaches weekly, which adds up to over 4,300 samples per season. We test the water for two different types of fecal bacteria; Enterococcus in marine water, and E. coli in fresh water. It is important to note that these two bacteria are considered indicator organisms, which, as their name implies, are used to “indicate” the presence of conditions that have the potential to cause illness. Both organisms are found in the intestines of warm-blooded animals, including humans. Their presence in recreational waters suggests that other harmful organisms and viruses (called pathogens) might be present. If these pathogens are inadvertently ingested while swimming, they may cause a variety of diseases, the most common of which is a mild gastroenteritis with flu-like symptoms. This can be inconvenient and even dangerous, especially for those who are immunocompromised.
You might wonder what causes harmful bacteria to get into the bathing water. Stormwater runoff is a dominant cause for elevated indicator bacteria levels. Runoff carries pollutants from roads and other paved surfaces directly to the surface water of beaches and ponds. Other possible causes of fecal contamination of recreation waters are animal wastes from pets and wild animals. Common waste observed on beaches can be from dogs, geese, ducks, seagulls, seals and fox.
In order to adequately protect beach goers Cape wide and maintain compliance with Massachusetts Bathing Beach Regulations 105 CMR 445.000, Barnstable County utilizes a seasonal staff of four bathing beach sampler/analysts to collect and analyze weekly beach water samples. The samples are delivered to our water quality laboratory and analyzed for the indicator organisms described above. It takes 24 hours to determine if the bacteria are present in a given sample. The maximum allowable number of Enterococci are 104 colony forming units per 100ml of marine water, or 235 colony forming units per 100ml of fresh water. If these standards are exceeded, a sampler is deployed immediately to collect a re-test. Based on recent amendments to the bathing beach regulations, the beach may remain open unless the results of the re-test indicate levels higher than the Massachusetts standards. Some beaches that have a history of consecutive closures over the last four bathing seasons must be closed after only one exceedence.
When a beach sample exceeds the limit for bacteria in bathing water, our program notifies the health agent in the town where the beach is located and they have 24 hours to ensure that the beach is closed to swimming. When re-test results show acceptable bacteria levels, the beach may be re-opened to swimming. Please remember that a beach posted closed to swimming does not mean you cannot still enjoy walking on the beach, collecting seashells, building sand castles and playing sports.
For more information regarding our program, our testing methodologies, closure policies and more, please refer to our frequently asked questions.