Article of interest: High-Tech Monitoring Improves Timeliness of Illinois Beach Closures

["Christine Manninen" <manninen@glc.org>]

>From the NOAA Coastal Services magazine, Jan/Feb 2005...

http://www.csc.noaa.gov/magazine/2005/01/article3.html

PDF (includes photo) is at
http://www.csc.noaa.gov/magazine/2005/01/issue.pdf

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High-Tech Monitoring Improves Timeliness of Illinois Beach Closures

They were able to come up with an equation where they can plug in all the
variables in current time and predict E. coli concentrations.  

When coastal resource managers have to wait 24 hours for the results of
water quality tests that show unsafe levels of E. (Escherichia) coli
bacteria, their subsequent decision to close beaches can be a day late in
protecting swimmers. Managers in Lake County, Illinois, have developed a
high-tech E. coli prediction system, which during trials last summer
dramatically increased the speed and accuracy of beach closure decisions. 

The system, called SwimCast, uses meteorological equipment to monitor a
beach's environment, such as air temperature, wind speed and direction,
water temperature and clarity, sunlight, and wave heights-all factors that
can hinder or encourage the growth of E. coli. 

"Right now, SwimCast is being shown to have been 86 to 87 percent accurate"
at the two beaches where it was tested, says Mark Pfister, aquatic biologist
for the Lakes Management Unit of the Lake County Health Department. "That's
far superior to what we've seen in past years when we were 67 to 100 percent
wrong in calling swim bans just on testing alone." 

Pfister cautions that SwimCast is not meant to replace government-mandated
water sampling but to augment it. 

E. coli contamination of coastal waters comes from human and animal fecal
matter, and is used as an indicator of other harmful human pathogens that
can potentially cause gastrointestinal illness in swimmers. 

Pfister says that there is a public perception that Illinois has a lot of
beach closures when compared to other Lake Michigan beaches. He says the
comparisons are "apples to oranges" because monitoring for E. coli is done
daily at Illinois beaches, which is far more frequent than that of
neighboring states. 

"The more you monitor, the greater the probability that you are going to
find changes in the E. coli concentrations," he says. "One day, you can have
a high count and the next day it can drop dramatically." 

The state's coastal managers are often frustrated by an 18 to 24 hour delay
in getting monitoring test results back from laboratories, which means that
swimmers can be in the water during peak times and may be kept out of the
water when it is safe. 

Because of this, Lake County managers began looking at all the independent
variables that might affect E. coli concentrations. They were able to come
up with an equation where they can plug in all the variables in current time
and predict E. coli concentrations. 

The data for the equation comes from $30,000 worth of monitoring equipment
on the beach that is continually sending readings to a data logger. "The
beauty is you can log in any time of day to look at the readings," he says. 

The initial cost of purchasing the monitoring equipment was paid for by a
grant from the U.S. Environmental Protection Agency. 

Pfister says the system could be used in other coastal areas, but because it
is not "off the shelf" and the cause of elevated E. coli at each beach may
be different, a new equation would need to be developed for each site. 

More testing of the model also is needed, he adds. "It's been very effective
to date. We want to continue making sure we maintain the same level of
accuracy next year."

For more information about SwimCast, contact Mark Pfister at (847) 377-8028,
or mpfister@co.lake.il.us. 

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