ILLINOIS POLLUTION CONTROL BOA~2

November

23,

1977

UNION ELECTRIC COMPANY,

)

Petitione~,

v.

 P03 77—92

ENVIRONMENTAL PROTECTION AGENCY,

RespondentS

OPINION AND ORDER OF THE BOARD

 (by Mr. Goodman):

On March 16,

 1977, Union E ~rric

 Company

 (UE)

 filed a Petition

for Rule 203(1) (5) Decision beto~~the Board.

 On April

14,

 1977,

we indicated that the studies submitted to the Environmental

Protec-

tion

Agency

 (Agency)

 in January,

 1976,

 in conjunction with PCB

76-89,

a petition for variance from the 5~yeardelay incorporated in Rule

203(i) (5), constituted Petitioner~ssubmission under Rule 203(i) (5).

A hearing was held in this matter

on

July

8,

1977

 in Edwardsville,

Illinois.

 At the hearing the parties submitted a Stipulation.

No

citizen witnesses testified.

The subject of this Petition

is

UE~sVenice Power Plant, which

is on the east bank of the Mississippi River in the City of Venice,

Madison County,

 Illinois.

The

plant

withdraws water from the

Mississippi River for use as non-contact cooling water to cool and

condense steam and discharges the warmed condenser cooling water to

 the Mississippi River.

 The plant has been discharging thermal

effluent to the river

 in this manner for over 25 years.

UE has submitted and the Board has accepted three reports to

satisfy the requirements of Rule 203

Ci)

(5),

 all conducted by

Equitable Environmental Health, Incorporated

 (EEl-I).

 The EEH Reports

are entitled:

(a)

 Assessment of the Venice Plant Cooling Water

Discharge Plume;

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245

—2—

(b)

Dernonstrati~~..

of

Venice

Power

Plant

Thermal

Discharge

Effects

Biological

Populations

the

Mississippi

River;

~ind

(c)

Venice

Report

Appendices

PA-H.

EEH conducted surveys

of

the

Venice

thermal

 plume

in

July,

August and November,

 1974 and March~~1975 by measuring water temper-

atures at several locations along a number of transects and at a

number of depths.

 During the surveys, UE operated the Venice Plant

as close as possible to maximum gen~:ratingcapacity.

 Based upon

these actual plume measurements,

EEH

produced a

 :iodel for prediction

of plume dimensions under other than survey conditions.

 From the

actual thermal plume surveys and modeling results, EEH concluded

that the Venice thermal plume meets

 all aspects

 of the applicable

Illinois water quality standards fcr temperature specified in Rules

203(i) (3)

and

(4)

 under both

survey

and historical worst case

conditions.

The maximum temperature rise ~:ermittedoutside the mixing

zone by Rule 203(i) (3), 5°F,

was met

for all months except July.

Additionally, EEH found that un~c conditions of minimum daily

river flow the 5°Fisotherm has

 surface area of only 2.6 acres

and occupies

 a maximum of 8.6

of

the river flow.

 For the minimum

daily flow ever observed in July,

 the hottest month of the year,

the 5°would enclose only 2.0 acres and 4.0

 of the

 flow.

The EEH reports indicate that phytoplankton, periphyton, zoo-

plankton, rnacroinvertebrates,

 and fish in the vicinity of the Venice

Power Plant were sampled from July,

 1974,

through June,

 1975.

The

sampling methods are described in both the reports and the Stipu-

lation.

 EEH concluded that the phytoplankton do not suffer

significant ecological harm from the thermal effluent.

 Temperatures

 that are potentially lethal for some phytoplankton (98-100°Ffor

large diatoms and about 111°for green algae) would be approached

only during a limited portion of the year and then only under extreme

conditions.

 Only

 a fraction of one percent of the river’s drifting

plankton would ever be exposed,

 and the exposure would be brief

(less than 10 minutes maximum).

 Similarly, EEH concluded that zoo—

plankton do not incur ecological harm due to the Venice Plant’s

thermal plume.

 EEH found no unusual zooplankton in any samples.

Under worst possible plume conditions,

 identified as maximum ambient

temperature of 88°F,maximum plume temperature of 108°Fand maximum

exposure time of 10 minutes,

 only a small percentage of the drifting

zooplankton would encounte: unfavorable plume temperatures.

The

zooplankton actually entrained through the condenser system, and

28

—

246

—

3..

thus exposed to the highest temperatures for longer time periods,

showed slight,

if

 any, effects

from such exposure.

Periphyton,

 or attached a1gae~

showed

adverse

effects.

undesirable community shift from

 ui. toms to blue-green algae were

observed in the vicinity of the

pIitt,

and

algae

communities

 were

similar above,

 at, and below

the

discharge of the Venice Power Plant.

Also,

 EEH concluded that, even with all units

 in operation, the area

of the heated Venice plume was

 so t:~ansitoryand small that the

thermal discharge does not affect macroinvertebrate populations in

the vicinity of the plant.

The fish sampling program at Venice found

twenty fish species,

all of which are common to this region of the Mississippi, and also

revealed that fish are relatively

low in numbers.

 EEl-I reported that

no fish mortality due to the

Venice

thermal plume was observed at

any time during the study.

 Since

the mobility of the fish allows

them to avoid the warmest areas

the

plume,

 some minor seasonal

distributional modification was

observed.

 There was some indication

that species of game and commerc~~ fish avoid the warmer plume areas

in July and August, but more

 fi;~b

~~re present at the plume station

than at the upstream station

in

 ~ptember.

 Similarly,

 in April,

a

preference for plume over ambiei~ttemperatures was observed.

 EEl-I

concluded that the distributional modification resulting from fish

 seeking their preferred temperature. range

 is very slight and causes

no ecologically significant adverse effects.

The EEH Thermal Effects Status Report also addressed the

possibility of “cold shock” resulting from southern plant shut-

downs

 in the winter when fish occupying the plume and acclimated

to the warmer plume temperatures

are quickly exposed to colder

ambient river temperatures.

 The EEH Report concluded that cold

shock has not been a problem, and outlined several reasons why

it would not be expected to occur.

 First, Venice generally does

not operate at high loads for sustained periods during the winter.

Fish attracted to the plume would not be exposed to the higher

temperatures for long enough periods to become acclimated.

 Second,

to the extent that acclimation of some fish might occur within the

small plume resulting at low loads, plume temperatures would

generally be within the range from which acclimated fish could with-

stand a sudden return to ambient.

 Moreover,

 at Venice’s typically

low loads a relatively large proportion of condenser cooling water

is recycled through warming lines during the winter,

 so that the

small thermal discharge plume would

be

correspondingly reduced in

size.

 Thus the potential

 or harmful acclimation of fish is

 even

further limited by the extremely small size of the plume within

—

247

which such acclimation

could possibly

occur.

 Third, the tendency

particular

fish

which

are

 quite

abundant in the locale to move

into deeper water and become

less

active

during

the

winter

indicates

they are unlikely to congregate

in

the vicinity of the Venice plume.

Results of the EEH sampling

program

did suggest such a trend.

Finally, although UE instituted

an

operating program designed to

take the Venice Plant off the

line

entirely on the weekends, these

shutdowns will not be characterized by a sudden drop from rela-

tively high loads to no load,

but

rather by a gradual step down to

very

low loads from which the

Plant

will be shutdown.

 Thus,

if

any fish are attracted to the

warmest

portion of the plume long

enough to become acclimated,

they

will be gradually exposed to

cooler temperatures

 as the Plant load decreases and the plume

subsides.

EEl-I

reported that the

shoreline

near Venice

 is not particu-

larly suitable for fish

spawning or

nursery activities.

 Additionally,

fish spawning is most intense

at, or

close

 to, times of highest

river flow and thus smallest

thermal plumes.

 The plume configu-

ration indicates that the plume

wc~uid

not impede upstream migration

of spawning fish.

 EEH,

therefc~:,

found that the thermal discharge

at Venice does not have any

effe~:t

fish

spawning,

behavior

nursery areas.

The Board finds that

Union Electric

has satisfied its burden

under Rule 203(i)

(5)

 of Chapter

3.

 Union Electric has demonstrated

to the satisfaction of the Board that, based upon the operating

practices outlined in the EEH Reports,

 the discharges from the

Venice Power Plant have not

caused

and cannot reasonably be ex-

pected to cause significant ecological damage to the receiving

waters.

 The Board finds

 that,

 assuming the operational practices

designed to minimize the possibility of ecological damage are

continued, no corrective measures will be necessary.

This Opinion constitutes the findings of fact and conclusions

of law of the Board in this matter,

ORDER

It

 is the Order of the

Pollution

Control Board that Union

Electric Company has complied with Rule 203(i) (5)

 of Chapter

3

in that it has demonstrated

that

discharges from the Venice

Power Plant have not caused and cannot reasonably be expected

to cause significant ecological damage to the receiving waters,

the Mississippi River.

28

—

248

—5—

I, Christan

 L. Moffett,

 Clerk of the Illinois Pollution Control

Board,

hereby

certify

the

~bove

Opinion

and

 Order were adopted on

the

 day of

(J~~

 1977 by a vote of

,~fr

Christan

 L. Moffè

 Clerk

Illinois Polluti

 ontrol Board

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249