TATE OF THE GREAT EAKES 2003
CAN WE SWIM AT THE BEACHl
E. coll and Fecal Coliform Levelr
The Issue: Many beaches in the Great Lakes are posted
as unsafe or closed for swimming each summer because of
bacterial pollution.
Bacterial contamination commonly occurs when
major rainstorms flood combined sewage
systems, carrying both raw sewage and
stormwater.
Flooded systems discharge sewage, rich in
bacteria such as E. coli and fecal coliforms, into
the Lakes.
Bacterial contamination may also occur from
improper storage of animal manure or the use
of manure to fertilize agricultural fields. Heavy
rainfall can then cause bacteria laden waters to
run off into the Lakes.
Bacteria can lead to diarrhea, cramps, nausea,
headaches, and other symptoms in swimmers
exposed to these contaminated waters.
The Indicator - SOGL 2003
This indicator examines the relationship between
E. coli and fecal coliform levels and beach closures.
The presence of E. coli and fecal coliforms in
recreational waters indicates that the water may be
contaminated with human or animal waste. If
E. coli or fecal coliforms are detected above
established limits, then swimming at beaches is
posted as unsafe or closed. U.S. and Canadian
health authorities monitor for these microbes to
protect swimmers from exposure, to refine
predictions of episodic poor water quality, to
pinpoint sources, and to decrease the number of
beach closures and postings over time.
The Assessment
Monitoring for microbial contamination at beaches
has increased substantially in recent years. Beach
water quality reporting has risen from 298 U.S.
beaches to 313 U.S. beaches and from 218
Canadian beaches to 304 Canadian beaches from
1998 to 2001. Beaches that posted swimming
restrictions or warnings for more than 10 percent
of the season fluctuated from 9 percent to 14
percent of Great Lakes beaches in the United States
and from 9 percent to 22 percent of Great Lakes
beaches in Canada (Figure 1).
United States Great Lakes Beaches
Percent Time with Beach Advisories and
Closures
D 0% Closed/Posted
D 1% - 4% Closed/Posted
D 5% - 9% Closed/Posted
>10 % Closed/Posted
Canadian Great Lakes Beaches
Figure 1. Proportion of United States and Canadian
Great Lakes beach advisories from 1998 to 2001.
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CAN WE SWIM AT THE BEACH?
As the frequency of monitoring and reporting
increases, more advisories and closures are
observed. Furthermore, the method of issuing
these advisories is occasionally imperfect.
Processing bacterial contamination test results can
take one to two days. Researchers are working on
more efficient bacterial contamination detection
tests that will allow authorities to close beaches
for swimming or post them as unsafe as soon as
the indicator bacteria appear.
The Outlook
Further work is necessary to develop better
detection methods, consistent monitoring
programs, and better swimmer warnings. These
issues are being addressed in the U.S. through the
Beaches Environmental Assessment and Coastal
Health (BEACH) Act of 2000. Through this act, a
freshwater E. coli indicator is being adopted in all
coastal and Great Lakes states. In Canada, the
1998 Beach Management protocol has
standardized guidelines for beach monitoring.
On a local level, many municipalities are
developing long-term control plans to better
address wet weather days and stormwater
runoff. Stormwater runoff was cited in 2001 as
the major wet weather cause of higher bacterial
levels monitored at beaches.
Federal, state and
provincial, and
tribal leaders are
collectively
working to better
protect Great Lakes
beaches. The U.S. Great Lakes Strategy envisions
that 90 percent of Great Lakes beaches will be
open for 95 percent of the season by 2010.
For More Information...
Visit the web site, www.binational.net, to access
the State of the Great Lakes 2003 and other
references reporting on the state of the Great
Lakes.
12/03
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