A new rapid water-quality test may prevent beaches from being closed by
providing accurate same day results of bacteria levels, according to a 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, 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
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
might have prevented hundreds of beach closure days and possibly
significantly decreased incidences of waterborne illnesses. The full report
is available online at
“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, of
“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,” she
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 polymerize chain reaction for
enterococci, is recommended by the EPA, but 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.