ILLINOIS
POLLUTION
CONTROL
BOARD
November
23,
1971
In
the
Matter
of
~R
70—16
MISSISSIPPI
THERMAL
STANDARDS
Opinion
of the Board
(by Mr.
Currie)
Existing standards
(SWB-12
and SWB-13)
limit temperature
in the Mississinpi River
to
90°F.,
and
in any case
tCno
more than
50
above natural temperature,
outside
a mixing zone extending
600’
from the coint of
a heated discharge.
Cf.
Application of
Commonwealth Edison Co.
(Dresden
~3)
,
~7O—2l
(March
3,
1971).
The construction
of
a large nuclear generating station
(the
Quad-Cities :~J~hntof Commonwealth Edison Co.
and Iowa-Illinois
Gas and Electric Co., slated
for oneration
in
the summer
of
1971)
on
the Nississipoi
at Cordova prompted the filing
in
December
1970 of
a citizen petition, by the
Izaak Walton League,
prooos~ng
that
we adopt
a
new
stanoara
ror
coat part of
Li~
river,
which
would abolish the mixing zone,
limit effluents
to
5°
above
natural
temperatures
at
the
maximum,
and provide monthly
maximum effluent temperatures
that would at times require less than
a
5°
rise over natural temneratures.
We broadened th~oroposal
to apely to the entire Illinols portion of the river
and scheduled
public hearings.
At about the same time
the federal Environmental Protection
Agency
was
reexamining
the
adecuac~
of
existing
standards
from
the
headwaters
to
the
mouth
of
the
Mississippi.
At
a
January
meeting
in
St.
Louis,
attended
by
representatives
of
most
of
the
river
states,
the federal agency put forward
a proposed new
set of
standards, based
upon
a
maximum
5°
rise
in
the river itself but
with monthly maxima, based
on
existing temperature records and
on the needs
of
the
local
biota,
that
were
not
to be exceeded
in
the river itself at any time.
The monthly maxima increased
as
one proceeded downstream through several zones of differing
natural temperatures.
The
zone boundaries
and the monthly
maximum figures were sone~ihatrevised and presented to the states
again at a second St.
LOUiS
meeting
in March.
We published the
federal proPosal as
an elternative
to he considered
in
further
hearings
in
this proceeding.
This
Board
was
rc
resented
at
both
the
federal
meetings
in
St.
Louis,
and
we
have
incoroorated
the
transcripts
of
these
meetings
in
the
present
record.
We
held
hearings
of
our’
own
in
—
177
Rock Island in February
and
in
Alton
in Roril.
Moreover,
in
February
we
received an application from
Commonwealth
Edison
and
Iowa—Illinois
for
a permit
to
operate
the
new
Quad-Cities
power
station.
At Edison’s request
we
agreed
to incorporate the evidence
on thermal discharges
from the permit proceedings
into the pre-
sent record in order to avoid duplication
of testimony,
The federal
agency also offered
to present evidence relevant to the standards
at the permit hearings, which began
in Rock Island May
24 and
lasted for eleven days.
After thorough study of
the voluminous
record,
we published
a proposed final draft June
28,
and
a revised final draft proposed
on
August
13,
based upon the federal proposal with several modifications
discussed below.
As required by our procedural rules, we kept
the record open for comments until September
9.
After
a final
consultation with federal and other state officials November
12,
we today adopt the regulation
in
a slightly modified form from the
August
13,
1971 draft.
The reasons underlying
the final regulation
£ o 1
low:
Citizen testimony
at the February hearing strongly suggested
that,
in the absence of regulation,
a single large power plant such
as Quad—Cities would have
a serious adverse effect on the ecology
of
a substantial portion of the river.
Quad-Cities,
the record
shows
will have two 809—megawatt
units
and
will
pour 2270 cubic
feet
per second of cooling water into
the iive~ at
a semp~ratuie 23~F,
warmer than the river
(Permit hearing,
pp.
32,
763).
The seven-day
low
flow
recorded
once
in
ten
years
at Clinton,
Iowa,
fifteen
miles upstream from Quad-Cities
and representative
of the Quad—
Cities
flow,
has been 13,200 cfs since the augmentation of low
flows
from
navigation
dams
in
1939
(Permit
hearing,
pp.
696—703,
714).
The lowest one—day flow
in the past
30 years has been 10,900
cfs
(id.,
p.
715)
.
Thus
at
low water
the discharge from Quad-
Cities will comprise
1/4 to
1/5
of the entire river
flow,
and it
will be 23°above normal when
it reaches the stream.
Quad-Cities
will
discharge
into
Pool
14
of
the
river,
which
is
rich
in
assorted
fish
of
considerable
game
and
commercial
value
(Feb.
24,
p.
23;
p.
81)
;
the value
of its sport fishery was
estimated at $149,000
per year by
the Illinois Department
of
Conservation
(Permit Hearing,
P.
2070)
.
Three
valuable species
in
the pool were said
to be near
the southern limit of their tolerance
(Apr.
23,
pp.
81,
110).
Five species,
it was argued, could be serious-
ly affected by
a thermal barrier 10-20° above normal temperatures,
both
because
of
the
floating
of
drum
eggs
~nd
fry
downstream
into
areas
heated
above
lethal
limits
and
because
of
the heating of
inshore
spawning
in
areas
during
seasons
when
cool
water
is
necessary
for
reproduction
(Feb.
26,
pp.
28-20,
46-47),
Therg
was
evidence
from
a
commercial
fisherman
that
carp
and
buffalo
have
moved
away
from
the
plume
of
a
much
smaller
power
plant
near
Genoa,
Wisconsin,
and
that
catfish
in
areas
affected
by
the
Genoa
plume
have
failed
to
spawn
(id.,
pp.
74-78).
With
recorded
natural
temperatures
approaching
90°
on
occasion
in
this
part
of
‘the
river,
the
effluent
itself
will
sometimes
be
as
warm
as
110°
(iii,,
pp.
89—90).
The situation depicted by these witnesses, however,
is
predicated on an absence of any measures to minimize the area of
the river affected or to increase the rapidity of mixing.
In
fact the existing regulations make the extreme results postulated
illegal.
The power companies had originally planned simply to
discharge the heated Quad-Cities effluent at the end of a wing
dam
into the main
river
channel, so as to minimize warming of
sensitive
inshore areas; but a 1970 simulation modeling demonstrated
this
plan
would
not
meet
the
existing
standard
,of
5° above
natural,
with
a
90° maximum,
at
the
edge
of
a
600’
mixing
zone
(Permit hearing,
p.
768).
Consequently the companies designed and
are planning to construct a $6,000,000 diffuser
(Permit hearing,
p.
1762), a pipe that will extend most of the way across the
river
bottom and
discharge heated water at numerous points to
facilitate rapid mixing.
It is the companies’ position that by this means they can
comply with the existing standard.
Downstream, after complete
mixing with as little as 10,500 cfs
(which is slightly below the
lowest daily flow in the past 30 years), the entire river will
be raised by 4.8°(Permit hearing, pp. 763, 786, 2259); this low a flow
occurs less than 0.5
of the time (id.,
p. 786).
Virtually
all
the necessary mixing will occur within 600’ downstream of the
discharge pipe (Sd., p.
783),
and
most of it within 40’
Lid.,
pp.
2236-37).
As for the absolute 90°standard, temperature records
at Davenport, 22 miles downstream and said to reflect Quad-Cities
temperatures, reveal temperatures as high as 85°on only four days
in ten years, or 0.1
of the time (id., pp. 858—63); so that a 4°
ris, at the edge of the zone, the companies expect, will almost
always be allowable
(id., p.
824).
Moreover, within the mixing zone
itself, the companies say, most of the mixing will occur before
the
discharge
reaches
the
surface,
so
that
temperatures
near
the
surface
will
not
be
raised
more
than four or five degrees anywhere on
the
river
even
under
the
worst conditions
(id., pp.
784-85).
Edison
and
Iowa-Illinois
thus
argue
that
with their diffuser
they will avoid the extreme river effects pictured by Walton League
witnesses and comply with the existing standard.
They further
argue,as will be spelled out below, that in doing sd they will cause no
significant adverse effects on the river, and that, since the
diffuser warms the whole river 4°at low water at the edge of the
zone, they could not meet the proposed federal standard (86°,when
normal temperatures reach 85°),or,
of
course, the
proposed
5°
effluent standard, without installing costly.cooling ponds or
cooling towers
(Permit hearing,
p. 825).
The federal position is, as the federal agency has also
argued as to the Ohio River and as to Lake Michigan (If R 71-12,
R 70-2), that the present standard is inadequate to protect aquatic
life against temperature extremes during various seasons of the
year.
Monthly maximum temperatures, it is argued, are necessary
3—179
in order to avoid temperatures
(which may be less
than
5°
above natural)
that
are high enough to endanger
the viability
of any
species
(Jan.
20.
p.
93)
.
The maxima proposed are based
upon
the biological needs
of the
fish
actually present
in each
section
of
the
river
and
on
actual
high
temperatures occasionally
encountered,
on the ground that these are
the temperatures
to
which the local
fish
are adapted
(id.,
pp.
37,
83).
A single
90°limit,
a witness from the Bureau of Sport Fisheries and wildlife
explained,
is
inadequate, partly because there are much lower
critical t~nperatures for fish reproduction during cooler times
of
the year
(Mar,
3.
pp.
145 et
seq.).
For
a detailed discussion by
federal fish biologist Donald Mount of
the
need
for
monthly
maxima,
see Mar,
3.,
pp.
94-130.
The utilities counter this argument with
a comparison
of
fish life
in Pool
14,
to which Quad—Cities will discharge, with that
in Pool
19,
170 miles downstream
(Permit hearing,
p.
967).
During
low-water conditions
the temperature of Pool 14 will be raised
by Quad-Cities,
as presently planned,
by 4°F., so that
its
temperature will
on occasion he
as much as 1.9° above that
naturally occuring
in Pool
19 downstream
(Id.
,
p.
946)
.
The biota
of the
two pools
are said to be similar, with
the same percentages
of walleye,
crappie,
carp,
and drum,
although there
are more catfish
in Pool
19.
Northern pike and yellow perch
are said
La be
insignificant
in Pool
14;
walleye,
sauger,
and buffalo to be found
in substantial
numbers
as
far south as Pool
25
(300 miles below
Pool
14)
,
where temperatures are
2 1/2-5° above those
in
Pool
14
(id.,
pp.
949-55,
968).
The catch per acre is said
to be generally
(not always,
id,,
p.
979)
better in
the
downstream Pool
19
(Id.,
p.
949)
.
Consequently the companies conclude, while conceding
that species success at
high
temperatures
elsewhere
might
be
the
result
of
adaptation
(id.,
p.
1009),
that the expected discharge
from Quad-Cities will
not
result
in
any significant change either
in species distribution or in
total
numbers
of
fish
present
(Id,,
pp.
950,
982).
As
in the Lake Michiqan
and Ohio River proceedings,
#~
R70-2
and
R71—l2,
we
find
the
federal
argument
in
favor
of
monthly
maxima
highly
persuasive,
for
the
reasons
given.
If
we
were
dealing
with
a
small
fraction
of
the
river
volume,
we
might
be
content
with
a
limit
of
5°
above
natural
temperatures
at
the
edge of
a mixing zone,
anticipating that further dilution would
rapidly reduce temperatures
in the river
as
a whole
to near normal
levels.
But the Quad-Cities evidence makes plain that
that
is not
what
is
at stake here.
At low flow this single plant will utilize
one-fifth to one-fourth of the river
for cooling purposes,
and after
complete mixing the entire volume
of the river below the plant will
be raised four
to
five degrees above intake temperatures.
Complete
mixing
will
be achieved 600~
downstream,
hut
the
temperature
reached at
the
edge of this
zone
will
persist
for
a considerable
distance downstream,
since there is no additional water for further
dilution.
Elevated temperatures across
the
entire river will therefore
remain until relatively
slow processes such
as evaporation dissipate
the excess heat
to the atmosphere.
Edison~s witnesses could
not
say how
far downstream
temperatures
would
remain above normal
(Permit hearing,
840);
an Izaak Walton League witness,
extrapolating
from
the
experience
of
the
upstream
Genoa
plant,
estimated
that
recovery
would
take
ten
miles
(Feb.
24,
pa.
81,
88)
;
a federal witness cuoted
a Commonwealth Edison study showing that
two and
a half miles would be
required
(Apr.
23,
p.
77); Edison itself in oral argument June
21
estimated that
at
low
water
a
3°
rise
over
natural
temperatures
would
persist for twelve miles.
The
utilities
argue
that
no
significant
harm
will
be
done
if
the
entire
river
is
occasionally
raised
four
or
five
degrees,
because
the same species thrive
at higher temperatures
170 or
300 miles
downstream.
The utilities conceded that ‘this might
be due to
adaptation,
so that increase
in temperature
in Pool
14 might impose
a stress on the population
there, which
is used
to cooler water.
Acclimation,
as
a federal fish biologist testified,
can alter the
lethal temperature
(Permit hearing,
p.
1354).
We could not with
equanimity comtemplate making the river warmer
for significant
periods
at Quad—Cities
than
it
is
many
miles
hel,o’~i
Keeki,*.
as adm~itted~
will be
the case at low water at Quad—Cit.ies
(Permit hearing,
p.
886)
To move
this section of the river
170 miles south,
in effect, would
bg
a substantial
alteration
in
natural
conditions.
Though similar
biota may
be
able to thrive at both latitudes under appropriate
circumstances, we think the threatened deviation from normal
sufficiently
great to create
a risk to the existing population that
is greater than should be
taken,
Moreover,
the hiota are not
entirely
the same
in the
two poois.
The Illinois Department
of
Conservation has
identified
13 fish species in Pool
14
not present
in
Pool
19
(Permit hearing,
p.
2069).
The
blue sucker,
grass pickerel
and
rainbow
trout
(an introduced species,
i,d.
,
p.
2106)
are
“sporadic”
in
Pool 14 and “any ecological change could very well
eliminate
these
three species
entirely
from Pool
14”
(if.
,
p.
2072)
Rainbow and carpsucker are at
the
southern end
of their
range,
and
yellow
perch and northern pike,
found in small numbers
in
Pool
14,
are close to their marginal temperatures
although they also occur
further
south;
a
4°
rise
over
a significant time period might
interfere
with
pike
or
perch reproduction by causing premature
spawning
when
food
is
unavailable
for the young
fish
(id,,
pp.
2089—2101)
.
Further,
a Wisocnsin state fish expert testified that
temperatures
of 85° to 95°can be injurious
to walleye spawning
(if.,
p.
1967)
and that
a disease called myxbolus
is likely to
attack bluegills, white bass,
and black crappies when temperatures
reach
85°
for
a
few
days during spawning season
(id.
,
p.
1977)
While the evidence falls short of conclusive proof that serious harm
could
necessarily
result
if
the
present
standard
were
retained,
we
think
no
such
showing
is
required.
The
day
is
past
when
contamination
of
the
environment
wi,.l
be
ci
lowed
until
gross
injury
occurs;
we
think
it
important
to
avoid
substantial
and
unnecessary
risks
of
harm,
and therefore agree that monthly maxima should be adopted.
However,
Edison has submitted additional temperature
data compiled by Dr.
H.
D. Tomlinson
of Ryckman, Edgerley, Tomlinson
and Associates which indicate that the originally proposed federal
maxima did not truly reflect the actual temperature experience
of the river.
Using Dr.
Tomlinson’s data as
a guide the June
and September maxima for
an intermediate
sector between the
Iowa Border
and
the Alton Lock
artd Dam have been raised one degree
above
the maxima specified for the Zonebetween
the Wisconsin
and
Iowa Border.
The maxima.for July and August for the intermediate
sector north of Alton have been increased two degrees.
We
believe that these slight modifications, based on more complete
information
than was available at
the
time
of last winter’s
St.
Louis meetings, more accurately reflect
the
existing natural
conditions
to which
the biota are actually exposed than do the
original
federal
proposals,
for
the following reasons:
The Mississippi River temperature standard
as
proposed
on
June
28
provided
for
an
86°F. maximum in July and August
with an
excursion
provision of 8°F.
fox.
up
to
5 1/2
days
in a year.
An examination of daily temperature data recently
received for
the 27—year period from 1944-1970
as recorded at the
Alton,
Illinois water treatment plant revealed 21 periods
totallincr
137 days
of temperatures
at 86°F. or higher.
The
intent of the temperature’ regulations
is to determine
the “natural” highs by month
arid
to
permit,
in general, 5°F.
above these highs,
except when
the resulting temperature would
adversely affect aquatic life.
The standard is then
set
to
not
permit
the full 5°F,envelope
to be used
if damage will occur.
Obviously
it
is
then of critical importance
to know the
“natural”
high
temperatures,
The data analysis revealed that
88°F. in July
and August and 86°F. in June
and September w~re
more realistic “natural highs”
at Alton
(the southern
and warmest
portion of its
zone),
It
is clear that what
is
to be feared is the warming
of
the river over
a biologically significant period
of time.
An expert witness favoring the
federal proposal testified that
a 4°rise above natural conditions
for as much as
a week
on
rare
occasions
would
not
injure even the sensitive northern
pike
(Permit
hearing,
p.
2114),
No
one
testified
to
the
contrary,
3
—
182
and a federal spokesman suggested that provision might reasonably
be
made
to
allow
the
maxima
to
be
exceeded
for
brief
periods
(March
3,
pp.
221).
We have so provided, by analogy to the existing
provisions that require water quality standards generally to
be
met
except during conditions of lowest flow.
We believe on
the present record that ample protection will be afforded
during these short periods by requiring adherence to the 5°-above
natural limitation and by providing that the mazima themselves
never
be
exceeded
by
more
than
3°.
It
is
not without
importance
that
this
provision
will
very
likely
result
in
the
saving
of
something
like
$40,000,000
at
the
Quad—Cities plant alone without creating any significant additional
risk to the river.
The utilities believe their diffuser pipe
•.will enable
them
to meet the 5°limit at all times, and the
monthly
maxima
except
during
rare
occasions
when
extremely
low
flows
coincide
with
extremely
high
natural
temperatures,
measuring
the 600’ mixing zone f;om the center of the pipe.
To require
the installation of alternative cooling facilities to be used less
than 1
of the time, we believe, would not under the circumstances
be warranted.
We add that
our
initial fears
that.
the wide diffuser
pipe might not leave a sufficient zone of passage for organisms
to travel up and down river (Permit hearing, pp.
1234-39) have
been allayed by evidence showing that the jets of warm water
from the diffuser (5°and more above natural t’emperdtures)
will occupy far less than 25
of the cross-section of the
striam.
The brief of the Attorney General in the Quad—Cities
case objects to the new regulation on the ground that it will
not assure a zone of passage that is at natural water temperature.
But our conception of the zone of passage is that it limits the
shape of a mixing zone ~o that not too much of the river’s
cross—section exceeds the water quality standard; having set
a standard that we think will protect aquatic life if achieved
in the river as a whole, we do not believe a still tighter standard
is needed for .the zone of passage.
The monthly maxima apply to the main river and not to
shallow
backwaters
where
natural
temperatures
are
likely to
exceed
the
prescribed
limits
on
sunny
days.
The
5°-above-
natural
limit
applies
everywhere,
and
to
meet
the
maxima
in
the
main
river
shottl~.assure
that
temperatures
in
shallow
areas, which are naturally higher, are not e~çcessive.
The exact size of the mixing zone is not a matter for scientific
determination.
There is nothing magic about 600’; like the 21 (or 18)-
year voting age, it
is a number selected to draw a rough but clear
line to separate points on a continuum.
Perhaps 300’ or 1000’
3—183
would be equally acceptable.
What
is
clear
is
that
a
small
portion
of the river
may
safely be warmed and
a large portion nay not,
and
the exact ocation
of
the
dividing
line
is
obviously
less
important
than
that
a clear
line be drawn somewhere
for
the guidance of
government
agencies
and
of river
users.
In another proceeding
we
have proposed,
state—wide,
to establish a minimum zone of passage
in addition to the 600
limitation
on
mixing
zones
(P71—14);
on
the wide
Mississippi
,
the
600’
zone itself serves in many cases
to assure
a
zone
of passage.
As
for the
federally
proposed monthly maxima,
it is
clear that exmanding
the
mixing zone
to
1000’ or even more downstream
of
a diffuser pipe such
as planned
for Quad—Cities
would make little
difference;
as the principal mixing occurs within 600’
,
there is little
dilution water downstreah,
and the 4°rise over natural at low
flow will persist for much farther down the river.
Moreover,
the
federal agency has made clear that
600’
is the largest zone
acceptable on the Mississippi
(Permit hearing,
pp.
1234-39),
and
we think that it is
a reasonable
size.
The Izaak Walton League ptoposal would do away with mixing
zones altogether by providing
that effluents discharged
to the river
themselves not exceed prescribed monthly maxima,
and that effluents
in no case be more than 5°above natural temperature.
This concept
has
the support of both
the state Department
of Conservation
(Apr.
23,
p.
85)
and the state Environmental Protection Agency
(ex.10).
Ideally,
of
course,
nothing would be discharged
to any
stream that is of poorer quality than the stream quality standard
itself;
no
portion
of
the
river
would
he
allowed to exceed
the standard.
Even
the
proponents
oi
the
efiluene
abdlldard,
however,
recognize
that
the
addition
of
very
small
volumes
of
high-temperature
water
to
a big
river
have
no
significant
effec~
and
that
the
costs
of
prohibiting such discharges would far exceed the observable benefits.
Thus
a
Walton
League witness acknowledged that the proposal was
not meant
to apply to discharges
from motorhoats
(Feb.
24,
p.
19-20)
and
the
federal
agency,
which
never
took
a
firm
stand
on
the
desirability
of
mixing
zones
(except
to say
600’ would be
the maximum
acceptable)
,
proposed that discharges from sewage treatment plants,
water
purification plants,
vessels,
closed—system blowdown,
and other
small
sources
be
exempted
from
the
standard
(Permit
hearIng,
Pp.
1234-39).
The
mixing
zone
is
a simple means
of protecting the river as
a whole while avoiding the imposition of substantial cooling costs
on smaller installations that affect an insignificant fraction
of the river.
Apart from
the
utilities constructing
the mammoth
Quad-Cities plant, none of the
industrial
users
of
Mississippi
River water objected to the adoption of the federal standard with
a
600’
mixing
zone,
apparently
because
this
affords them ample room
in
which
the river can assimilabe their discharges.
And the total
area of
the
river affected
by
these sources,
if that
is true,
is
insignificant,
Principal existing sources are
the following power
plants:
CILCO,
216 mw at Grand
Tower;
Iowa—Illinois,
99
mw
at
Moline;
Union
Electric,
500
r:oT
at Vonice and
300 mw
at Wood River
(Mar.
3,
p.
195).
Illinois Power testified against the effluent
standards
but
said
it could
rrteet both the monthly maxima and the
5’~ rise limitation at
the edge
of
a
600’
zone,
The
impact
of
an
effluent
standard
upon
still
smaller
contri-
butors
oi
heat
was
graphically
demonstrated.
Several
industrial
3—184
water
users
testified
without
contradiction
that
in
order
to
meat
th
proposed
effluent
standards
even
wet
coolina
towers
would
not
suffic
since
wet
bulb
temperatures
sometimes
exceed
the
proposed
limits;
refriperation would he
required
(Thr.
23,
up.
116-27
(Shell Oil)
,
149-59 (Corn Products)
,
159-62
(American Oil)
,
64-77
(Olin)
,
127—48
(Illinois
Power)).
The
evidence
is clear that
most
of these discharges,
at least, will disappear within
600
feet.
This
evidence
shows
the
desirability
of
mixing
zones
in
order
~to
avoid
the
expenditure
of millions
of dollars
to escape perfectly
trivial
effects on the
river.
Effluent standards
of course have the advantage
of easy
enforcement;
one simply measures the temperature
of
the
discharge,
and,
to determine
the increase,also
of the intake.
Dipping
thermometers into
the stream 600
feet around
a discharge point is
more cumbersome and
less accurate,
But it
is perfectly acceptable,
as
was
suggested by
the federal EPA,
that compliance with
the
stream quality standards he generally determined by theoretical
computations based on relative temperatures
and
volumes of effluent
and of receiving stream
(Jan.
20,
p.
75)
,
subject
to
refutation
by actual measurement.
As
was
brought
out
in
cross—examination
by
the Quad-Cities
utilities,
the
new
standard,
like
the
old,
does
not
afford
complete
protection
for
the
river
because
it
does
not
limit
the
number
of
mixing
zones
that
may
exist
(Pe~mit
hearing,
u.
1 27~)
,
it
is
therefore
sti±1
possible
for
a
substantial
pu~LiOa
O~
the
to
be
heated
beyond
the
standard
by
a
proliferation
of
host
sources
each
affecting
only
a
very
small
area.
In
order
to
fill
this
gap
in
the
regulation
we
have
proposed,
in
another
prgreedine
(#R
71—14),
to
limit
the
total
use
of
cooling
water
within
any
several mile
stretch
of
any
stream.
Pending
dcci sion
as
to
that additional pronosal, we think the standard
‘ac ado
I
today
provides
a
reasonable
ii,rst
stea,
and
a
significant.
imorovement
on
the
earlier
standard,
toward
full
strean~
protection.
The availability
of alternative cooling devices such
as ponds,
towers,
or
spray
canals
to
meet
the
now
standard
is
not
in
.issac;
for
a
full
discussion
of
alternatives
see
the
Board’s
opinion
in
#R
70— 2,
Thermal
Standards
Lake
lb clii
~‘min
.
The
companies
‘
amended
application considers such
ci
tern~
Lives
in
seme
detail.
We
believe
that, where required by
the
new
standard,
the
costs
and
environmental
disadvantages
(see
opinion
in
fE
70-2)
of
ponds, tower~
or spray canals are justified
in order to
avoid
a
substantial altera~
in the temperature
of
a significant portion of the
stream.
As on Lake Michigan,
we
also
require that the effects
of
new
large sources
be
studied
and
that
coarection
be
made
if
significant harm is shown.
The
present
standards
are based
on
curren
knowledge,
which
is
incomplete;
we
mus
review
them
in
the light of
future learning.
3— 185
We have included in the regulation a provision allowing
for
re-examination
of
any
permit
iT
future
development
shows
a need to reallocate the heat capacity of the stream.
The
ability of the stream to absorb heat without
harm
is a limited
and valauble resource,
and
we cannot simply resign it.enti7rely
to the first corner.
To deny permits today on the basis that
future development migjit require reallocation of the permittee’s
share would leave the resource unused in the interim,
we think
it preferable to give fair
warning
that
the
grant
of
a
permit
is
not
a
deed
of
irrevocable
rights
as
against
future
prospective
users.
3—181
ORDER
I.
Rule 1.05 c of Rules and Regulation SWB—12, Rule 1.05
(4)
and 2.05
(3)
of SWB-l3 are hereby amended to read
as follows:
All sources of heated effluents shall meet the following
restrictions optside of a mixing zone which shall extend no
farther
in any direction from .an effluent discharge than 600
feet.
The mixing zone shall include no more than one-fourth
of the cross sectional area of the river nor shall it, at any
time,
extend to more than one-half of the surface of any river
sector.
A.
There shall be no abnormal temperature changes
that
may
affect aquatic life unless caused by
natural conditions.
B.
The normal daily and seasonal temperature fluctuations
that existed before the addition of heat due to other
than natural causes shall be m~intaincd.
C.
The maximum temperature rise at any tfte or place
above natural temperatures shall not exceed 5°F.
D.
In addition, the water tem?erature at representative
locations
in
the
main
river
shall
not
exceed
the
maximum limits in the fo3lo~singtab3e dnring more
than one percent of the hours in the 12—month period
ending with any month.
Moreover, at no time shall
the water temperature at such locations exceed the
maximum limits in the following table by more than
3°F.
JAN.
FEB. MAR.
APR.
MAY
JUNE JULY 1~UG.SEPT.
OCT.
NOV. DEC.
Mississippi
River
(Wisc.
45°
45° 57° 68° 78°85° 86° 86° 85°
75° 65° 52°
Border to Iowa
Border)
(°F)
Mississippi
River (Iowa
45° 45° 57° 68° 78°86° 88° 88° 86°
75° 65° 52°
Border to Alton
Lock and
Dam)
(°F)
Mississippi
River
(So. of
Alton Lock &
50”
50° 60° 70° 80°87° 89° 89° 87° 78° 70° 57°
Dam)
(°F)
3—187
Main
river
temperatures
are
temperatures
of
those
portions
of
the
river
essentially
similar
to
and
following
the
same
thermal
regime
as
the
tem-
peratures
of
the
main
flow
of
the
river.
II.
A.
The owner or
operator
of
a
source
of
heated
effluent
which
discharges
0.5
billion British thermal units
per
hour
or
more
shall
demonstrate
in
a
hearing
before
this Board not
less than
5 or more than
6
years
aftei
the
effective
date
of
these
regulations
or,
in
‘the case of new sources,
after the commence-
ment of operation,
that discharges
from that source
have not caused and cannot be reasonably expected
to cause significant ecological
damage
to
the
River.
If
such
proof
is
not
made
to
the
satisfaction
of
the
Board,
appropriate
corrective
measures
shall
be
ordered
to
be
taken
within
a
reasonable
time
as
determined
by
the
Board.
B.
Permits
for
heated
effluent
discharges,
whether
issued
by
the
Board
or
the
Environmental
Protection
Agency,
shall
be
subject
to
revision
in
the
event
4~T~’
r(’~anabl e
future
devlb
opment
creates
a
need
for
rcailocation
of
the
assimilative
capacity
of
the
river
as defined in the regulation
above.
C.
The
owner
or
operator
of
source of heated effluent
shall
maintain
such records and conduct such studies
as
may be
required
by
the
Environmental
Protection
Agency or
in any permit granted under the Environ-
mental Protection
Act.
D,
Appropriate
corrective
measures
will
be
required
if,
upon complaint
filed
in
accordance with Board
rules,
it
is
found
at
any
time
that
any
heated
effluent
causes
significant
ecological
damage
to
the
River,
III.
Rule
1,07
(4)
of
SWB—l2
and
Rule
3,01
(4)
of
SWB—l3
are
hereby
repealed.
3
—
1B~
