Beach Water Testing
May Be Flawed
IRVINE, California, August 16, 2002 (ENS) - The recent
rise in beach closures across the country could be due in
part to flawed sampling techniques, suggests a California
A July report by an environmental group, the National
Resources Defense Council (NRDC), found that there were
19 percent more beach closures and advisories in 2001
than in the previous year, which the group attributed
to increased monitoring and better testing standards for
bacteria and other pathogens.
However, most of the closings were triggered by a single
sample, said Dr. Stanley Grant, professor of environmental
engineering at the University of California at Irvine,
and an author of a report released this week. Because
water quality changes so fast, an effective single sample
program would require minute by minute updates, Grant
"You'd have to have a stop light up on the beach flashing
green and red," Grant said. "It flashes red and everybody
would have to run out of the surf; it flashes green and
everybody could run back in."
The high number of closings based on the single sample
method has prompted public concern about water quality
at America's beaches. Using a 43 year history of data
and several sampling surveys, Grant and his coauthors
studied the surf water quality at Huntington Beach, California.
Huntington Beach made national headlines in the summer
of 1999 when a large section was closed to the public,
drawing attention to beach water quality around the country.
But since then, the researchers found, water quality has
been improving in response to large scale investment in
waste treatment and disposal in the region.
"I think there's actually a positive environmental message
here," Grant said. "There's been a lot of money spent
over the years on mitigation and we can clearly see the
impacts of that."
The researchers found that coastal water quality is
controlled by an intricate relationship among a number
of physical and biological factors, such as tidal cycles,
seasonal rainfall and El Niño events. This complexity
makes beach water monitoring difficult, and raises questions
about existing monitoring programs across the country.
In October 2000, Congress passed the federal BEACH act,
which is designed to ensure consistent national health
standards for beach water by 2004. States will have to
meet U.S. Environmental Protection Agency (EPA) standards
to receive federal funding for the monitoring programs.
The EPA has not issued final rules for implementing
the BEACH act, and Grant is concerned that the bill could
turn the single sample standard into law. Grant favors
the use of an averaging method, similar to that used to
determine unsafe air quality in urban areas.
Current EPA guidelines do include an averaging method,
but local authorities are far from consistent in their
sampling strategies, according to the NRDC report.
Grant's study appears in the August 14 Web edition of
"Environmental Science and Technology," a journal of the
American Chemical Society.