Chicago River formerly
flowed into
Michigan
'
|Chicago
River
,
lock
.
‘
'
LAKE MICHIGAN
The Metropolitan Sanitary District of Greater Chicago. The area between Highway
50 and the Indiana border is a heavily industrialized city suburb.
_
shallow Lake Eric, enabling the vegetation to utilize the nutrients, and thus
intensify eutrophic conditions. Canals and cooling waterconduits might provide migration routes into the Ohio River for unwanted species of sh, just as
other man—made structures have opened the way for undesirable species elsewhere in the Great Lakes.
'
The purpose in discussing the Great Lakes plan here is not to weigh its
merits, other than to identify some of the questions that must be answered.
Rather, the plan illustrates the way
in which the techniques of diversion and
augmented ow and the concept of dilution can be carried to extremes by
modern technology.
—
Mixing Zone. - Associated with the concept of dilution is that of the mix:
ing zone. This term refers to lateral, vertical, and longitudinal forces, partic'
ularly those caused by turbulence, that disperse pollutants to a certain con—
centration within a given time and area in a stream or other body of water
[6]. The mixing—zone concept is an important consideration in setting stream
'
quality standards, which in the United States aregenerally determined by the
allowable concentration of pollutants in a stream itself rather than in waste
discharges. Formules are used to calculate the anücipated mixing and dis—
persion of pollutants in a given stream. This enables oicia15 to determine, for
'
'
Symptomatîc Treatment
9
_
flowed into
Michigan
'
|Chicago
River
,
lock
.
‘
'
LAKE MICHIGAN
The Metropolitan Sanitary District of Greater Chicago. The area between Highway
50 and the Indiana border is a heavily industrialized city suburb.
_
shallow Lake Eric, enabling the vegetation to utilize the nutrients, and thus
intensify eutrophic conditions. Canals and cooling waterconduits might provide migration routes into the Ohio River for unwanted species of sh, just as
other man—made structures have opened the way for undesirable species elsewhere in the Great Lakes.
'
The purpose in discussing the Great Lakes plan here is not to weigh its
merits, other than to identify some of the questions that must be answered.
Rather, the plan illustrates the way
in which the techniques of diversion and
augmented ow and the concept of dilution can be carried to extremes by
modern technology.
—
Mixing Zone. - Associated with the concept of dilution is that of the mix:
ing zone. This term refers to lateral, vertical, and longitudinal forces, partic'
ularly those caused by turbulence, that disperse pollutants to a certain con—
centration within a given time and area in a stream or other body of water
[6]. The mixing—zone concept is an important consideration in setting stream
'
quality standards, which in the United States aregenerally determined by the
allowable concentration of pollutants in a stream itself rather than in waste
discharges. Formules are used to calculate the anücipated mixing and dis—
persion of pollutants in a given stream. This enables oicia15 to determine, for
'
'
Symptomatîc Treatment
9
_