(Data from U.S. STPs was unavailable, in part due to
SOLEC Indicators
security reasons.)  Based on analysis of the three Canadian
city-regions on a per-capita basis, the findings for three of
Since the 1996 State of the Lakes Ecosystem Conference,
the parameters were:
SOLEC organizers and participants have attempted to
develop and refine a suite of ecological and socio-
total suspended solids discharges were comparable or
economic indicators for the Great Lakes basin ecosystem.
greater for sewage treatment plants than for storm
SOLEC indicators provide a method for measuring progress
toward meeting the terms of the Great Lakes Water Quality
phosphorus discharges were about 50 times greater
Agreement.  SOLEC indicators are selected based on three
from sewage treatment plants than from storm water;
general criteria: necessity, sufficiency and feasibility. The
1996 SOLEC paper, Impacts of Changing Land Use,
copper discharges were between 2.5 to 20 times
included an initial list of 36 Great Lakes land-use indicators.
greater from sewage treatment plants than from storm
That list has been revised during subsequent SOLEC events.
There are presently 12 SOLEC indicators under the
category of “land and land-use” among a broader suite of
Large variations among sewage treatment plants for total
118 ecosystem indicators, many of which are also related to
suspended solids suggest the need for better data collec-
land use.  See the inset for details of a review some of the
tion and improved methods of estimation for this param-
land and land-use indicators.
eter.  For phosphorus and copper, the findings suggest that
sewage treatment plant discharges are greater than storm
Consultant Background Work
water on a per capita basis.  This finding reinforces the
significance of improving and maintaining sewage treat-
To examine and build on the scientific understanding of
ment plants, which are associated with urbanized and
linkages between urbanization and water quality, the SAB’s
urbanizing (e.g. urban and suburban) areas.  In addition to
Parties Implementation Work Group contracted with GHK
overall amounts discharged, the way in which these
International Consulting (Toronto, Ontario), to examine
compounds reach our water ways is also a consideration.
urbanization trends in six Great Lakes city-regions:  Chi-
Additional research could improve our understanding of
cago, Milwaukee, and Duluth in the United States; and
the implications of different deliveries of contaminants on
Toronto, Windsor, and Collingwood in Canada.  The
the physical (e.g. hydrologic) and chemical integrity of
selected focus areas were to provide samples of varying size
receiving waters.
and lake basin.  For each city-region, the consultant was
asked to forecast and map population growth and urban
At the same time, the consultant’s findings suggest that per
boundaries to 2031 and comment on water quality impacts,
capita storm-water runoff decreases with increasing
infrastructure demands, potential mitigation methods (e.g.
population density. This finding supports related research
best management practices, conservation design) and
showing that increased impervious surface cover, associ-
policy implications. The consultant was also asked to look
ated with low-density development or sprawl, results in
specifically at five indicators related to water quality for
greater water quality degradation.  However, the research
each city-region:  phosphorus, total suspended solids,
did not examine effects of different urban forms, which
copper, imperviousness and estradiol.
would have required a separate study.  This supports the
need for further scientific inquiry comparing per capita
For three parameters, the consultant compared data from
discharge rates as a function of population density and
Canadian sewage treatment plants with storm-water runoff.
urban form.
Increased vehicular use (vehicular distance traveled)
The 1996 SOLEC paper, Impacts of Changing Land
associated with low density development and its contribu-
Use, included an initial list of 36 Great Lakes land-
tion to contaminants in storm water and atmospheric
deposition also was highlighted by the consultants.  Due to
use  indicators.    That  list  has  been  revised  during
time and resource constraints, the consultants were unable
subsequent SOLEC events.  There are presently 12
to specifically measure levels of impervious cover for the
newly developing areas in the six city-regions studied.  This
SOLEC indicators under the category of “land and
would be an important area of continued inquiry.  Findings
land-use” among a broader suite of 118 ecosystem
regarding estradiol discharges were inconclusive due to
indicators, many of which are also related to land
considerable variability and uncertainty in the scientific
literature and a lack available facility-specific data.