The Department of Health routinely samples and tests seawater from Bermuda's beaches to assure bathing water quality. The water is tested for enterococci, a group of bacteria which are used as indicators of pollution, in accordance with the US EPA methodology for Recreational Water Quality for Marine Water.
Enterococci are present in human and animal faeces and can enter marine waters from a variety of sources such as storm water runoff, animal and seabird waste, failing septic systems, sewage effluent, boating waste and from bathers themselves. During the peak months of April to October, Environmental Health Officers collect water samples at the most popular beaches with the larger beaches having multiple sampling points. As a result, approximately fifteen samples are collected and tested once a week.
The public will be notified if waters exceed acceptable values by posted notice on the affected beaches, media releases and by advisory at www.gov.bm.
The water quality data is summarized on links below. The graphs show the geometric mean ( a type of average) of the enterococci counts for each week at each sampling location. The geometric mean is calculated from the enterococci counts over a 30 day period and is updated each week. This is done according to the EPA recreational water guidelines, which recommend that the 30-day geometric mean does not exceed 35 enterococci per 100 millilitres. For comparison purposes this limit is marked in red on the graphs.