An edition of: WaterAtlas.orgPresented By: Sarasota County, USF Water Institute

Water-Related News

New Water-Quality Test May Prevent Unnecessary Beach Closures

A new rapid water-quality test may prevent beaches from being closed by providing accurate same day results of bacteria levels, according to a new study by the U.S. Geological Survey.

With increasing outbreaks of waterborne illnesses, beaches have been at the forefront of recent research on human health risk. This new rapid water-quality test, developed by the Environmental Protection Agency (EPA), will help managers across the country determine whether beaches are safe for swimming in order to keep the public from getting sick. Previous tests could not provide same-day results, so managers had to decide whether to close a beach based on findings from the day before.

USGS scientists analyzed the accuracy of EPA's rapid test by looking at past water quality data from five beaches along Lake Michigan to determine what the outcomes would have been if the rapid test was used. These findings were then compared to two older methods of testing which require 24 hours for results. Scientists discovered that results from the rapid test met EPA’s safe swimming criteria more often than the older tests. If this method had been used during the study period examined, the summers of 2009 and 2010, it may have prevented hundreds of beach closure days and possibly significantly decreased incidences of waterborne illnesses. The full report is available online (see link below).

"This study provides beach managers with a virtual "test drive" of this tool; it gives them an idea of what they can expect in terms of beach monitoring decision making," said USGS scientist Meredith Nevers. "Our research shows that EPA’s rapid test can be an effective tool for beach managers to help keep their recreational beach goers happy and safe."

Beach closures not only impact recreational users in the summertime, but they also create huge losses for the local economy. Studies have found that the value of a beach trip is between $20-$36 per person per day — revenue which may be lost to local economies when beaches are closed.

The new rapid test, called quantitative polymerase chain reaction for enterococci, is recommended by the EPA, but it is not a requirement. The test has been included in the 2012 EPA guidelines for safe levels of indicator bacteria, including: Escherichia coli (E. coli) and enterococci. The test can be used at both freshwater and marine beaches. To learn more about EPA’s recreational water quality criteria, visit their webpage.