TATE  OF  THE GREAT LAKES 2003
   CAN WE DRINK THE WATER?
        Drinking Water Quality
The Issue: Millions of people depend on the Great
Lakes for drinking water free of chemical and
microbial contamination.

»  The Great Lakes region is home to
   approximately 33.5 million people, a
   majority of whom depend on one of the five
   Great Lakes for drinking water.

»  The region has been subjected to decades of
   pollution, threatening the integrity of the
   Lakes and the purity of the water for
   consumption.

•  Testing determines the chemical and
   microbial contaminant levels in drinking
   water and the effectiveness of policies and
   technologies intended to protect the safety
   of drinking water.

The Indicator - SOGL 2003
This indicator tracks the integrity of Great
Lakes water by examining data
from a portion of the basin's
public water systems (Figure 1)
including the concentrations of
contaminants such as:

•   Atrazine: an agricultural
    pesticide;
•   Nitrate/nitrite: naturally occurring
    nutrients that are found at high levels in
    fertilizers; and,
•   Total coliform, E. coli, Giardia,
    Cryptosporidium: disease-causing
    organisms that can contaminate water
    supplies.
                                St. Lawrence River Water
                                River Water
                                Lake Water
                                Groundwater
 Figure 1. Public water systems that provided data for the
 drinking water quality assessment, as reported in the
 State of the Great Lakes 2003 report.

This indicator also examines the turbidity, taste, odor,
and organic carbon content as a way of assessing
drinking water supplies for other water quality
problems.

The Assessment
Chemical/Nutrient Contamination
Atrazine and nitrate/nitrite are consistently found at
minimal concentrations following water treatment
processes. Public water systems have rarely found
chemical levels exceeding drinking water standards
between 1999 and 2001 (Table 1).

Exceedances after
Treatment
Number of Public
Water Systems
Reporting
Atrazine
0
104
Nitrate/Nitrite
1
56
                                             Table 1. Number of atrazine, nitrate/nitrite violations of
                                             drinking water standards at reporting public water system
                                             facilities (1999-2001).

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  CAN WE DRINK THE WATER?
Atrazine and nitrate/nitrite are occasionally
detected in the Great Lakes basin. In the rare
cases where treatment is necessary, advanced
technologies are able to reduce the levels of these
contaminants so that the drinking water meets
standards.

The Assessment
Microbial Contamination
Microbial contamination of drinking water rarely
occurs after treatment.  Public water systems
monitor E. coli, a harmful bacterium; total
coliform, a benign group of bacteria often present
under similar conditions as E. coli; and other
harmful pathogens. On the U.S. side of the basin,
very few microbial violations occur in drinking
water following treatment, according to the U.S.
Safe Drinking Water Information System
(SDWIS) (Table 2). Higher microbial counts are,
however, measured in source waters.

Exceedances
Reported in
SDWIS
Number of Water
Treatment Plants
Reporting
Total
Coliform
1
48
E. coli
0
48
Table 2. Drinking water microbial violations reported
in the SDWIS from 1999-2001 in the U.S. Great Lakes
basin.
The United States and Canada
are developing rapid tests that
quickly detect the presence of
coliforms, E. coli, and other
microbial organisms such as
Giardia and Cryptosporidium.
Additionally, better data will be
generated to track the presence
of these organisms in both source water and
drinking water as detection techniques improve.


The Outlook
Water treatment technologies ensure the high
quality of our regional drinking water. Increased
development and the use of new chemicals in the
Great Lakes basin continue to threaten the
integrity of our source waters. Treatment
technologies are excellent, however, one of the
best ways to ensure high quality drinking water is
to reduce contaminant input into the basin.

The importance of high-quality source water
cannot be overemphasized. It reduces costs
associated with treating water, promotes a
healthier ecosystem, and lessens potential
contaminant exposure to humans.

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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