BEFORE

THE

ILLINOIS POLLUTION

CONTROL

BOARD

AMEREN

ENERGY

GENERATING

COMPANY,

TO:

NOTICE

OF

FILING

John

Therriault,

Assistant

Clerk

Illinois

Pollution

Control

Board

James

R.

Thompson

Center

Suite

11-500

100

West

Randolph

Chicago,

Illinois

60601

Joey

Logan-Wilkey

Illinois

Environmental

Protection

Agency

Division

of

Legal

Counsel

1021

North

Grand

Avenue,

East

P.O.

Box

19276

Springfield, Illinois

62794-9276

Carol

Webb,

Hearing

Officer

Illinois

Pollution

Control

Board

1021

North

Grand

Avenue,

East

P.O.

Box

19274

Springfield,

Illinois

62794-9274

Deborah

Williams

Illinois

Environmental

Protection

Agency

Division

of Legal

Counsel

1021

North

Grand

Avenue,

East

P.O.

Box

19276

Springfield,

Illinois

62794-9276

PLEASE

TAKE

NOTICE

that

I

have

electronically

filed

with

the

Office

of

the

Clerk

of

the

Pollution

Control

Board,

POST-HEARING

BRIEF

OF

AMEREN

ENERGY

GENERATING

COMPANY,

copies

of which

are

herewith

served

upon

you.

Ameren

Energy

Generating

Company

a

41

a

Petitioner,

)

)

)

)

V.

)

)

PCB

09-3

8

ILLINOIS

ENVIRONMENTAL

PROTECTION

)

(Thermal

Demonstration)

AGENCY,

Respondent.

)

)

)

By:

.Iny

Antoniolli

---

Dated:

August 13, 2009

Amy

Antoniolli

SCHIFF

HARDIN LLP

233

South Wacker Drive

Suite 6600

Chicago,

Illinois 60606

Tel:

312-258-5500

Email:

aantoniolli@schifthardjn.com

---

CERTIFICATE

OF

SERVICE

I,

the

undersigned,

certify

that

on

this

13

th

day

of

August,

2009,

I

have

served

electronically

the

attached,

POST-HEARING

BRIEF

OF

AMEREN

ENERGY

GENERATING

COMPANY,

upon

the

following

persons:

John

Therriault,

Assistant

Clerk

Illinois

Pollution

Control

Board

James

R.

Thompson

Center

Suite

11-500

100

West

Randolph

Chicago,

Illinois

60601

therriauj(ipcb.state.ii.us

Carol

Webb,

Hearing

Officer

Illinois

Pollution

Control

Board

1021

North

Grand

Avenue

East

P.O.Box

19274

Springfield,

Illinois

62794-9274

Webbcipcb.state.

il .us

Joey

Logan-Wilkey

Illinois

Environmental

Protection

Agency

Division

of

Legal

Counsel

1021

North

Grand

Avenue,

East

P.O.

Box

19276

Springfield,

Illinois

62794-9276

Jocy.

logan-wilkeyil1inois.gov

Deborah

Williams

Illinois

Environmental

Protection

Agency

Division

of

Legal

Counsel

1021

North

Grand

Avenue,

East

P.O.

Box

19276

Springfield,

Illinois

62794-9276

Deborah.wiIliamsillinois.gov

August

13,

2009

Amy

Antoniolli

SCHIFF

HARD1N

LLP

233

South

Wacker

Drive

Suite

6600

Chicago,

Illinois

60606

312-258-5500

By:

A6Jy

Antoniolli

---

BEFORE

THE

ILLINOIS

POLLUTION

CONTROL

BOARD

AMEREN

ENERGY

GENERATING

)

COMPANY,

)

)

Petitioner,

)

)

v.

)

PCB

09-3

8

)

(Thermal

Demonstration)

ILLINOIS ENVIRONMENTAL

)

PROTECTiON

AGENCY

)

)

Respondent.

)

POST-HEARING

BRIEF

OF

AMEREN

ENERGY

GENERATING

COMPANY

NOW

COMES

AMEREN

ENERGY

GENERATING

COMPANY

(“Ameren”

or

“the

Petitioner”

of “the

Company”),

by

and

through

its

attorneys, SCHIFF

HARDIN

LLP,

and

provides

this

post-hearing

brief

for

consideration

by the

Illinois

Pollution

Control

Board

(“Board”).

I.

INTRODUCTION

On

December

15,

2008,

pursuant

to

Section

302.211(j)

of

the Board’s

water

quality

rules

and

Section

106.200

et

a!.

of

the

Board’s

procedural rules,

Ameren

filed

this

Petition

to Modify

Specific

Thermal

Standard

(“Petition”).

In

the Petition,

Ameren

requests

a modification

to

the

thermal

limits

granted

by

the

Board

in

1982

for

the

cooling

water

discharge

from

Coffeen

Power

Station

(“Station”)

to Coffeen

Lake.

Ameren

seeks

relief

only

during

the months

of

May

and

October.

May

and

October

fall

within

the winter

regime

for

thermal

limits

applicable

to

Coffeen

Lake.

New

information provided

with

this

brief

in response

to

public

comment

received

by

the

Board

in this

proceeding

is

provided

in

the

nature

of

public

comment.

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

The new limits

Ameren seeks for May and October would

not represent new or

previously

unseen

temperatures for Coffeen Lake. Rather, Ameren

seeks an intermediate

limit

between the summer

and winter regimes

that would apply

only

during those

two months. The

intermediate

thermal limits would allow a more

gradual transition between the

winter and

summer regimes.

Ameren does not seek any other changes

to the current limits.

This Petition follows both significant

past investments as

well

as

a thorough investigation

of possible supplemental cooling technologies and

in depth

analysis

of the

impact of the

requested relief on Coffeen Lake. Ameren has already

made substantial investments

in cooling

technologies to control the Station’s thermal effluent to Coffeen

Lake. Ameren has

spent

$26

million on the construction of a

70-acre cooling

basin and a 48-cell, 200,000

gallon per

minute

(gpm) cooling

tower system. These technologies

have

been

effective at mitigating

the

thermal

component of

the discharge from

the

Station,

but despite these additions,

Ameren has

still had to

de-rate during May and

October from time

to

time

to meet the current limits

at times

when there

is demonstrated consumer

demand for

power from the Station.

In

recent

years, shifting

weather

patterns have brought

warmer

weather during these transition

months making the winter

limits

less representative

of

ambient conditions and, therefore, more

difficult for the Station

to meet.

Ameren has also thoroughly examined possible

enhancements to

the existing

cooling

technologies that

would

allow the plant to operate without having

to de-rate during

the shoulder

months. None of the alternatives that

would

have allowed Ameren

to achieve

this goal

were

technically feasible and economically reasonable.

The

relief

requested in this Petition

is the

only

economically reasonable and

technically

feasible alternative

available that would allow

Ameren

to

operate under forecasted operating

conditions without having

to

de-rate

during May

and

October. Given the minimal

environmental

impact

the

requested relief

would have

on Coffeen

-2-

---

Lake,

the modified

limit

Ameren requests

for May and October

is the

only

economically

reasonable

alternative

available.

Coffeen

Power

Station’s economic

and

social

value

to the community

and to

the State of

Illinois is

undeniable. Coal and

electric

generation are

essential parts

of the Illinois

economy.

As

a base-load

generator

with

high

reliability,

Coffeen Power Station

is

a

low-cost energy

provider

to

the people of Illinois.

Allowing

Coffeen Power Station

to operate

throughout

the

year

without

having to dc-rate

or shut down

altogether also provides

a benefit

to

the

retail

customers

in Illinois and throughout

the Midwest

region.

Ameren has

a

strong

record

of

environmental

stewardship

and,

pursuant to

a

lease

agreement

with the

Illinois Department

of

Natural

Resources (“IDNR”),

has

made

Coffeen

Lake available

for a wide

range of

public

and

recreational

uses on and

around

this “hidden

jewel” of a

lake.

However,

for Coffeen

Lake

to

remain

such a

valuable

natural

resource

to the

public

and

to the State of Illinois

as

a

whole,

Ameren must

be able

to

fully utilize

the lake

to

support its

generating

operations.

II.

PROCEDURAL

BACKGROUND

Ameren

filed its Petition on December

15,

2008.

On March

5,

2009, the Board

accepted

the Petition for

hearing and ordered the

Illinois

Environmental Protection

Agency

(“Agency”)

to

file its recommendation

on

the Petition

within

30

days, or

by April

6, 2009.

On the

same

day,

the Hearing Officer,

Ms.

Carol Webb,

issued

an order

directing

Ameren

to

answer a

series of

pre-hearing questions

posed

by

the Board.

On March

24,

2009,

Hearing

Officer

Webb,

together

with the

parties, set the public

hearing

for

May 19,

2009

to be

held in

Litchfield,

Montgomery

County.

The Agency requested

an extension

until April

17, 2009 to file

its recommendation,

but

did not file the

recommendation (“Recommendation”)

until April 24,

2009, nearly

three weeks

past

the deadline

set by the

Board and Hearing

Officer. Ameren

filed

answers

to

the Board’s

-3-

---

questions

and

the

pre-filed

testimony

of three

witnesses

on

May

12,

2009.

Due

to

the

late

filing

of

the

Recommendation,

Arneren

asked

to

postpone

the

hearing

until

June

23,

2009.

Hearing

Officer

Webb

conducted

the

public

hearing

on

June

23,

2009.2

Four

witnesses

testified

on

behalf

of

Ameren,

and

all

were

found

credible

by

Hearing

Officer

Webb.

Ameren

submitted

three

of

the

four

pre-filed

testimonies

as

exhibits

at

hearing.

Ameren’s

first

witness,

James

L.

Williams,

Jr.,

was

the

plant

manager

for

Coffeen Power

Station

from

2001

through

June,

2009.

Mr.

Williams

testified

as

to

the

current

thermal limits

and

Ameren’s

request

for

a

modification

to

those

limits,

Ameren’s

past

efforts

to

comply

with

the

thermal

limits,

Ameren’s

analysis

of

additional

cooling

technologies,

background

on

how

the

station

operates,

and

Ameren’s

economic

analysis

of the

alternatives

investigated.

Mr.

Williams’

pre-filed

testimony

was

admitted

as

Hearing

Exhibit

1 (“Exh.

1”).

Ameren’s

second

witness,

Dr.

James

McLaren,

is

a

fisheries

biologist

with

ASA

Analysis

and

Communication,

Inc.

(“ASA”)

with

over

35

years

experience.

Dr.

McLaren’s

pre-filed

testimony

along

with

his

Curriculum

Vitae

and

attachments

were

admitted

as

Hearing

Exhibit

2

(“Exh. 2”).

Dr.

MeLaren

testified

regarding

the

findings

of his

assessment,

which

evaluated

the

potential

impacts,

if

any,

associated

with

revising

Ameren’s

thermal

standards

for

the

months

of

May and

October for

Coffeen

Lake.

His

report

and

supporting

testimony

concluded

that

the

proposed

thermal

limits

would

provide

conditions

capable

of

supporting

shellfish,

fish

and

wildlife.

Ameren’s

third

witness

was

Dr.

Ann

Shortelle,

a

limnologist

with

MACTEC

Engineering

and

Consulting,

Inc.

(“MACTEC”).

Dr.

Shortelle’s

pre-filed

testimony

along

with

her

report

and

Curriculum

Vitae

were

admitted

as

Hearing

Exhibit

3

(“Exh.

3”).

Ameren

specifically

retained

2

The

transcript

of

the

June

23,

2009

hearing will

be

cited

to

as

“Tr.

at_.”

-4-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

Dr. Shortelle

to

address

the

Agency’s

concerns,

raised

in

the

Recommendation,

about

any

impact

the

requested

relief

might

have

on

mercury

and

phosphorus

loading

to

Coffeen

Lake.

Ameren

called

a

fourth

witness,

Mr.

Michael

Smaliwood

of

Ameren’s

environmental

sciences

department,

to

answer

questions raised

by

the

Agency

about

the background

and

purpose

of

a

2009

addendum to the

2007

Total

Maximum

Daily

Load

(“TMDL”)

analysis

for

Coffeen

Lake.

Tr.

at 221,

256.

Mr.

Smaliwood

also

testified

regarding

certain

conditions

in the

Coffeen

Power

Station

NPDES

permit.

The

Agency

submitted

one

exhibit

at

hearing:

Chapter

1

of

a report

drafted

by

Southern

Illinois

University

—

Carbondale (“SIUC”)

in

2000

(“Exh.

4”).

SIUC

conducted

studies

of

the

effects

of the

thermal

discharges and resulting

temperatures

on

Newton

Lake

and

Coffeen

Lake

from

1997

and

2006.

SIUC

studied

fish

species

and

habitat.

Several

of

the

annual

reports

were

submitted

as

attachments

to

various

filings,

and

the

Agency

filed

the

entire

series

of

reports

by

CD

on

July

13,

2009.

The

Agency

presented

no

witnesses.

Two members

of

the public

offered

oral

comments.

The

public

comment

period

was

set to

end

July

13,

2009.

Four

written

comments

were

filed

during

the

comment

period.

Ameren’s

deadline

to

submit

its

post-hearing

brief

was

set

for

August

13,

2009.

III.

AMEREN

HAS

MET

ITS

BURDEN

OF

PROOF

TO

SHOW

THAT

COFFEEN

LAKE

WILL

CONTINUE

TO

BE

ENVIRONMENTALLY

ACCEPTABLE

AND

WITHIN

THE

INTENT

OF

THE

ACT

An artificial cooling

lake

demonstration

is

a

unique

mechanism

that

provides

a procedure

specifically designed

for

steam-electric

generating

plants

that

discharge

to

artificial

cooling

lakes.

It allows

relief

from

the Board’s

temperature

limits

under

appropriate

circumstances

and

The

SIUC

Reports

will

be

cited

to

throughout

this

brief

as

“[Year]

STUC

Report,

pg.

-5-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

in

a proceeding that

is

adjudicatory

in

nature.

The

generally

applicable

thermal

water

quality

standard,

35

III.

Adm.

Code

302.2

11,

provides

this

exception

and

sets

forth

the

required

level

of

justification.

35

Ill. Adm.

Code

302.21

1(j)(3);

See

also

In

the

Matter

of: Water

Quality

and

Effluent

Standards

Amendments,

Cooling

Lakes,

R75-2

slip

op. at

25 (Sept.

29,

1975).

To

make

a

successful

demonstration

pursuant

to Section

302.21

1(j),

a

petitioner

must

show

that

the artificial

cooling

lake will

be

environmentally

acceptable

and

within

the

intent

of

the

Act.

35

Ill.

Adm.

Code

302.21

1(j)(3).

To

meet

the

environmentally

acceptable

burden

of

proof,

a

petitioner

must

show

that

the

cooling

lake can

provide

conditions

capable

of

supporting

shellfish,

fish

and

wildlife,

and

recreational

uses

consistent

with

good

management

practices.

35

Ill.

Adm.

Code

302.211

(j)(3)(A).

The

standard

also

requires

the Board

to

consider

technical

feasibility

and

economic

reasonableness

of controlling

the

thermal

effluent

when

promulgating

the

specific

thermal

standard.

35

Ill.

Adm.

Code

302.21

1(j)(3)(B).

Past

thermal

demonstrations

and

Board

proceedings

are

instructive

on

how

to

make

the

requisite

showing

and reveal

three

key

points

regarding

thermal

demonstrations.

First,

the

regulations

do

not

require

that

there

necessarily

be a

fishery

or

recreational

uses

of the

lake,

but

only

that

the

artificial

cooling

lake

be

capable

of

supporting

such

conditions.

Illustrating

this

point,

when

adopting

the

specific

justification

for

artificial

cooling

lake

demonstrations,

the

Board

stated:

{U]nder

subsection

(cc)

(1),

[now.

Section

302.211(j)]

it is

not absolutely

required

that

there

be

a fishery,

or

that

an

artificial

cooling

lake

provide

recreational

or any

other

uses

except

that for

which

it

was

designed.

. .

.

[bjut

it

is

nonetheless

felt

that

by

requiring

such

conditions

in

a

lake we

will have

taken

a

significant

step in

protecting

water

quality.

In

the Matter

of:

Water

Quality

and

Effluent

Standards

Amendments,

Cooling

Lakes

(Cooling

Lakes),

R75-2,

slip

op.

at 40

(Sept..

29

1975)

(emphasis

in

original).

Under

the

applicable

standard,

therefore,

Coffeen

Lake

clearly

need

not support

an

optimal

fishery,

but

simply

conditions

capable

of

supporting

a

fishery.

-6-

---

This

standard

does

not

require

that

the

fishery

meet

all

IDNR

lake

management

objectives

or

even

require

a finding

that

no

fish

kills

may

ever

occur

under

the

requested

relief.

When

granting

the

current

thermal

limits

for

Coffeen

Lake,

the

Board

found

Coffeen

Lake

environmentally

acceptable

despite

three

reported

fish

kills.

Central

Illinois

Public

Service

Co.

v.

IEPA,

PCB

77-158,

slip.

op.

at 6

(Apr.

27,

1978).

Despite

the

fish

kills,

which

the

Board

found

were

“not

significant,”

and

the exception

of

the stunted

condition

of

bluegills,

which

the

Board

noted

was

a

common

condition

in

reservoirs

and

probably

caused

by

too

great

a

population for

the

existing

food

supply,

the

Board

found

that

Coffeen

Lake

appeared

to

be in

good

condition. CIPS,

PCB

77-158,

78-100

(consol.),

slip

op.

at

2. The

Board

found

that

CIPS

had

met

its

burden

by demonstrating

that

the

lake

supported

a

variety

of

fish

and

had

not

sustained

any

dramatic

fish

kills.

Second,

the regulations

do not

require

a

showing

of

no

environmental

impact.

Notably

absent

from

the

thermal

demonstration

standard

is

the

requirement

to demonstrate

a lack

of

environmental

impact

on

the

waterbody

receiving

the

thermal

effluent.

Rather,

the

thermal

limit

must

maintain

conditions

in

the

artificial

cooling

lake

such

that

it

remains

capable

of

supporting

shellfish,

fish

and

wildlife,

and recreational

uses

consistent

with

good

management

practices.

For

example,

the

Board

found

that

minimal

impacts

to reproduction,

growth

and

survival

of

some

species

did

not

constitute

a

significant

ecological

impact

as

long

as the

adjusted

thermal

limit

would

not

inhibit

the

propagation

of fish

or other

aquatic

biota.

Petition

of

Illinois

Power

Co.

for

Hearing

Pursuant to 35

Ill.

Adm.

Code

302.211(j)

to

Determine

Specific

Thermal

Standards (Petition

of

Illinois

Power),

PCB

92-142,

slip

op. at

7

(Aug.

26,

1993).

Ameren’s

proposed

modification

to the

thermal

limits

in

May

and

October

does

not

limit

Coffecn

Lake’s

capacity

to

maintain

a

sustainable biotic

community.

-7-

---

Third,

while

the regulations

suggest

that

the

requisite

showing

may

take the

form of

an

environmental

impact

statement

or

Section

316(a)

demonstration, that

suggestion

is

not

a

regulatory

requirement. When adopting

this section

of

the regulations, the

Board

explained

that

subsection

(dd),

now

Section

302.2

11(j)(4),

was

meant

to minimize the

duplication

of

paperwork.

The

Board

stated:

It is

hoped

that

if presentation

of similar

facts

and data

before

other

agencies

or

regulatory

bodies

is required,

the same

materials

used

there

may

be

used

to

satisfy

the

showing

requirements

of subsection

(cc).

The

specific

instances

listed

in

that

section

are for

general

guidance,

and

it is expected

that

any

appropriate

reports

or

materials

which

address

the requirements

of

subsection

(cc)

may be

used.

Cooling

Lakes,

R75-2,

slip op.

at 41.

As

the

record

shows,

Ameren

has met

the elements

of

an

artificial

cooling

lake

demonstration

both

in

form

and

in substance.

For

these reasons,

Ameren

asks

that the

Board

grant

the

requested

modified

thermal

limit

for

the

months

of

May

and

October.

A.

Coffeen

Lake

Will

Continue

to

Provide

Conditions

Capable

of

Supporting

Shellfish,

Fish, and

Wildlife

1. Aquatic

Life

The

record

shows

that

Coffeen

Lake

supports

shellfish,

fish

and

wildlife

under

current

thermal

limits

and will

continue

to

do

so

even

under the

requested

modification.

Coffeen

Lake

exceeds

the

requisite

showing

and supports

a

thriving

fishery

that meets

or

approaches

IDNR’s

stated

objectives.

Ameren’s

fisheries

biologist

consultant,

Dr.

McLaren

of

ASA

Analysis

&

Communication, Inc.,

has conducted

an exhaustive

examination of

data collected

by

SIUC,

IDNR,

Illinois

Natural

History

Survey

(“INHS”),

and the

Company

to assess

whether

the

lake

has and

would

continue

to

support

a balanced

indigenous

aquatic

community

and

a thriving

recreational

fishery.

Dr.

McLaren

analyzed

the

potential

effects

of

raising

the

May

and

October

thermal

standards

by

performing

first

a retrospective

assessment,

which

reviews

historical

data

to

determine

whether

or

how

fish

populations

have

adapted

to

the

thermal

environment

in

the lake;

and

-8-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

second,

a

prospective

assessment,

which

predicts

how

the

lake’s

thermal

environment

during

May

and

October

might

be

altered

under

the

proposed

revised

standards.

Dr.

McLaren

has

concluded

from

these

assessments

that

Coffeen

Lake

does

support

a

balanced

indigenous

community

and

robust

recreational

fishery

and

would

continue

to

do

so

under

the

requested

relief

Tr.

at 26;

Exh.

2,

par.

6.

Dr.

McLaren

analyzed

three

species,

largemouth

bass,

channel

catfish

and

bluegill,

as

the

representative

important

species

(“RIS”)

in

conducting

its

retrospective

and

prospective

analyses

of

Coffeen

Lake.

Thcse

species

are

appropriate

because

IDNR

manages

these

species

and

because

they

are

recreationally

important

species,

self-reproducing,

and

predatory

species

that

reflect

the

status

of

lower

trophic

levels.

Tr.

at

158;

Exh.

3,

par.

6.

Additionally,

SIUC

focused

on

these

same

three

species

in

its

multi-year

studies,

providing

a

very

unique

and

fortunate

opportunity

to

have

a

long-term

database

of

hard

data

from

which

to

assess

the

effects

of

the

current

thermal

regime

on

these

species

of

fish.

Tr.

at

28.

Dr.

McLaren

determined

that

Coffeen

Lake

provides

a

diversity

of

habitat

at

any

time,

thermal

refuge

is

available

in

various

parts

of

the

lake,

and

the

epilimnion

remains

oxygenated

with

dissolved

oxygen

concentrations

usually

well

in

excess

of

5

milligrams

per

liter

(“mg/L”).

Tr.

at

29.

Ameren

has

addressed

questions

raised

by

the

Board

and

concerns

expressed

by

the

Agency

regarding

current

and

anticipated

lake

conditions

with

respect

to

aquatic

life.

Ameren

has

also

shown

that

Coffeen

Lake

has

not

sustained

any

dramatic

fish

kills,

and

those

that

have

occurred

have

not

had

any

lasting

effect

on

current

fish

populations.

Pet.

Exh.

11,

pg.

5-2;

see

also

Ameren’s

Response,

pg.

8

and

2004

SIUC

Report,

p.

TX-X,

27.

The

evidence

of

record

abundantly

supports

Dr.

McLaren’s

conclusion

that

proposed

warmer

May

temperatures

are

not

expected

to

carry

over

throughout

the

remainder

of

the

summer

season.

In

sum,

Ameren

expects

-9-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

aquatic

life

to

continue

to

thrive

under

the

requested

relief

and

the

record

contains

no

evidence

with

which

to

conclude

otherwise.

a)

The

Requested

Relief

Will

Have

No

Negative

Impact

to

Reproduction,

Growth

&

Survival

The

Agency

posed

a

series

of

questions

regarding

findings

of

the

2007

Lake

Management

Status

Report

by

IDNR

(See

Pet.

Exh.

12),

implying

that

the

fish

populations

in

Coffeen

Lake

did

not

meet

the

agency’s

objectives.

Dr.

McLaren,

however,

has

not

found

that

any

of

these

numbers

conclusively

demonstrate

stress

from

the

existing

thermal

regime

in

Coffeen

Lake.

Sec

Ameren’s

Response

to

the

Recommendation

of

the

Illinois

Environmental

Protection

Agency

(“Ameren’s

Response”),

pg.

8-9.

All

three

RIS

exhibit

characteristics

such

as

survival,

growth,

body

condition,

population

size,

and

recruitment

of

young

that

are

comparable

to

or

exceed

those

for

populations

in

other

regional

and

national

water

bodies.

Exh.

2,

par.

7.

While

some

annual

variability

in

population

characteristics

of

fish

species

has

occurred,

such

annual

variability

is

typical

for

any

sustainable

fish

population.

Id.

More

importantly,

there

has

been

no

sustained

declining

trend

in

relative

weight

through

time.

Depending

on

the

species,

the

numbers

in

the

2007

Lake

Management

Status

Report

more

likely

reflect

competition

with

other

species

for

food,

angling

pressure,

an

increasing

predator

base,

or

the

cyclical

nature

of

a

particular

species.

Tr.

at

173-185.

The

catch

per

unit

effort

(“CPUE”)

for

largemouth

bass

exceeded

the

lake

management

plan

objectives

for

the

previous

four

years.

Pet.

Exh.

12.

According

to

very

recent

IDNR

data,

proportional

stock

density

(the

percentage

of

stock

fish

equal

to

or

exceeding

quality

length)

consistently

has

been

higher

than

IDNR’s

goal,

indicating

a

high

quality

fishery

for

large

bass.

Pet.

Exh.

11,

pg.

5-2.

-10-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

Recruitment,

growth,

and

condition

of

the

RIS

indicate

that

lower

trophic

levels

in the

lake

4

are

available

to

provide

an

adequate

food

supply.

Pet.

Exh.

11,

pg.

5-2.

The

lack

of

evidence

of

detrimental

effects

of

water

temperatures

on

fish

recruitment,

growth,

and

condition

indicate

that

these

lower

trophic

levels

also

are

adapted

to

the

thermal

environment

of

the

lake.

Game

fish

are

positioned

at

the

top

of

a

finely-balanced

food

chain

and

the

thermal

effects

on

these

species

are

a

good

indication

of

general

conditions

in

the

lake

biota.

See e.g.

Cooling

Lakes,

R75-2,

slip

op. at

21.

The

record

also

shows

that

adequate

suitable

habitat

is

available

in

Coffeen

Lake

throughout

the

year

that

can

provide

optimal

water

temperatures

or

serve

as

a

nursery

for

young

fish

or

thermal

refuge

for

adult

fish.

Pet.

Exh

11,

pg.

5-2.

As

for

future

conditions,

Dr.

McLaren

predicts

that

the

proposed

thermal

limits

could

benefit

reproduction,

survival

and

growth.

Pet.

Exh.

11,

pg.

5-1.

Dr.

McLaren

found

that

the

survival

and

growth

of

the

early

life

stages,

particularly

for

largemouth

bass,

are

actually

improved

by

the

stable

warmer

temperatures

of

Coffeen

Lake

in

the

late

winter

and

early

spring

and

prolonged

growing

season.

Pet.

Exh.

11,

pg.

3-3.

Dr.

McLaren

suggests

that

this

gives

the

fish

a

better

ability

to

“bulk

up”

for

the

winter

to

increase

over-winter

survival

and

ultimately

achieve

larger

growths.

Tr.

at

168.

The

proposed

modified

limits

for

May

and

October

also

will

not

negatively

impact

reproduction.

The

requested

relief

is

not

expected

to

affect

the

dates

of

spawning

for

largemouth

bass

because

the

large

majority

of

spawning

in

the

heated

arm

of

the

lake

has

been

completed

by

May.

Tr.

at

142-43;

Pet.

Exh.

11,

pg.

3-2.

Higher

May

temperatures

should

also

not

adversely

affect

bluegills

because

the

record

shows

that

they

spawn

throughout

summer

when

temperatures

‘

Lower

trophic

levels

include

primary

producers

such

as

phytoplankton,

epiphyton,

and

macrophytes,

as

well

as

primary

and

secondary

consumers

such

zooplankton,

benthos,

and

phytomacrobenthos.

—11—

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

are

higher

than

the

proposed

limits.

Pet. Exh.

II,

pg.

5-1.

Dr.

McLaren

states

that

the proposed

October

limits

may

even

prolong

the spawning

season

for

bluegills,

which

in the

past

has

extended

into

September

and

October.

Id.

Channel

catfish

have

probably

experienced

earlier

spawning

in

Coffeen

Lake

due

to warmer

water

temperatures

during

spring

months.

Id.

As

is

the

case

for largemouth

bass,

early

spawning

would

allow

channel

catfish

to complete

early

life

stages

prior to

May

leaving

more

thermally-tolerant

juveniles

resulting

in

improved

summer

and

over-winter

survival.

Id.

Dr.

McLaren

has found

that

diversity

in water

temperatures

exists

in

the eastern

and

western

arms

of

Coffeen

Lake,

and at

depth,

providing

adequate

refuge

and

that

such temperature diversity

would

be

advantageous

for

all

fish species.

Exh.

2,

par. 20(b).

The

Agency

has

expressed

concern

about

whether

the requested

relief

will

lead to

fish

kills

in

Coffeen

Lake.

See

Rec.

at

20.

Historically,

fish

kills

have been

rare

events

usually

occurring

only

during

exceptional

conditions

of

prolonged

calm,

cloudy

weather

combined

with

unusually

warm

temperatures

when

the

lake

is stratified

and

DO

levels

are limited.

Exh.

2,

par.

13; Pet.

Exh.

11,5-3;

2007

STUC

Report,

p.8;

2006

SIUC

Report,

p.8

and

2005

SIUC

Report,

p.

5.

These

rare

instances

have never

been

reported

in

May

or

October.

The

proposed

limits

for

May and

October

will

not

likely

cause

fish

kills

since

water

temperatures

and

dissolved

oxygen

levels

associated

with

fish kills

have

not

occurred

and

would

likely

not

occur

during

those

two

months.

5

Pet.

Exh.

11, 5-3.

The

most

extreme

summer

weather

conditions

are

not

likely

to

occur

during

May

and

October.

Even

if such

conditions

did

occur,

the

proposed

limits

are well

below

the summer

thermal

standards

and

Ameren

would

be

required

to

de-rate

to comply

with

the requested

limits

during

those

months.

SIUC

has

found

that

from

data

collected

between

1998

and 2004,

the

most

critical

habitat

conditions

in

Coffeen

Lake

occurred

only

during

the

months

of July

and

August.

SIUC

Report

2005,

pg.

22,

25.

-12-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

Moreover,

historic

fish

kills

have

not

resulted

in any

long-term

negative

effects

to

Coffeen

Lake

or

the fish

populations.

Pet. Exh.

11,

pg.

5-2;

see also

Ameren’s

Response,

pg.

8

and 2004

SIUC

Report,

p.

IX-X,

27.

In

fact,

the

objective

of

the

SIUC

studies

was

to determine

if the

1999 fish

kill

and

subsequent

smaller

fish

kills

adversely

affected

the

three

sport

fish

populations

(channel

catfish,

largemouth

bass,

and

bluegill).

2007

SIUC

Report,

pg.

1.

SIUC

concluded

that

even

the

most

significant

fish

kill

observed

on

Coffeen

Lake,

in

July 1999,

was

relatively

insignificant

to

the

sporifish

populations.

2007

SIUC

Report,

p.

9; see

also

2006

SIUC

Report,

pg.

10 and

2005

SIUC

Report,

p.

6.

The

number

of

largemouth

bass

that

died

represented

1%

of

the population.

To put

this into

perspective,

the

average

total

annual

mortality

rate

for

largemouth

bass

in Coffeen

Lake

from

1997 through

2004

is

approximately

42%.

2006

SIUC

Report,

pg.

9.

The

record

also

shows

that

the 1999

fish

kill

was

not

induced

by

Ameren’s

thermal

effluent

to

Coffeen

Lake.

6

In the July

1999

event,

the

fish

kill

was attributable

to

conditions

beyond

high

discharge

water

temperatures

which

included

a combination

of prolonged

periods

of

hot

air

temperature,

and

low

levels

of

dissolved

oxygen

due

to atmospheric

conditions;

conditions

which

also resulted

in

fish

kills

in non-cooling

lakes

such as

East

Fork Lake

near

Olney.

2007

SIUC

Report,

p.

8;

see also

2006

SIUC

Report,

p.8

and

2005

SIUC

Report,

p.

5

The

results

of Dr.

McLaren’s

retrospective

and

prospective

assessments

demonstrate

that

under

the

proposed

limits

for

May

and October,

Coffeen

Lake

will

continue

to

provide

conditions

capable

of supporting

the reproduction,

growth

and

survival

of

aquatic

life.

6

“In

Coffeen

Lake,

the

temperatures

were actually

warmer

in 2003,

2004,

2005,

and

2006

than

in

1999.

However,

weather

patterns

(and

not water

temperatures)

in

2000-2006

likely

were

responsible

[for]

the lack

of

fish kills

versus

1999.

In

1999, temperatures remained

very

hot

for

a

number

of weeks.

In most

instances

following

1999,

very

hot

weather

was followed

for

a

few

days by

cooler

weather,

and

in

some

cases, heavy

rain

events,”

2007

SIUC

Report,

pp

13-

14.

-I

3-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

b)

The

Requested

Modifications

to

Thermal

Limits

During

May

and

October

Will

Not Lead

to

Higher

Maximum

or Average

Temperatures

During

Summer

Months

The

new

limits

Ameren

seeks

for May

and

October

would

not

represent

new

or

previously

unseen

temperatures

for

Coffeen

Lake.

Because

they

are new

limits

for

these

two

months

of

the year,

however,

Dr.

McLaren

analyzed

the

impact

of

the

requested

relief

on

lake

temperatures

and

concluded

that

warmer

lake

temperatures

in

May

would

not

carry

over

into

the

summer

months

of June

through

September,

when

ambient

temperatures

are the

highest

and

habitat

could

become

limited.

Pet.

Exh.

11,

2-4,

5-1;

Tr.

at

30;

Ameren’s

Response,

pg.

10-11.

Based

on

the evidence

of

record,

Dr.

McLaren

concludes

that

raising

water

temperatures

in

the

mixing

zone

during

May

does

not

automatically

result

in wanner

temperatures

throughout

the remainder

of

the season.

Pet.

Exh.

11,

pg.

2-4;

Exh.

2,

par. 19.

Dr.

McLaren

used

the

results

of thermal

modeling

done

by

Sargent

& Lundy

(“S&L”)

to

evaluate

future

potential

near-worst

case operating

conditions. The

modeling

shows

that

increasing

the

thermal

limits

in

May

would

not result

in a

carry-over

effect

into

the

summer months.

Exh.

2,

par.

19.

Dr.

McLaren

explained

that

this

is because

meteorological

conditions

are

the

controlling

factors

of

the lake

water

temperatures.

Tr.

at 32.

The

lake

dissipates

heat

through

surface

exchange

with

the

atmosphere.

Atmospheric conditions

influencing

the

ability

of

the lake

to

dissipate

heat

include

ambient

air temperatures, relative

humidity,

wind

and

wave

reaction,

and

solar

radiation.

Tr.

at

32;

Exh.

2,

par. 9.

SIUC

repeatedly

highlights

the

significant

impact

that

meteorological

conditions

have

on

lake

biological

conditions,

independent

of

water

temperature.

See

2007

SIUC

Report,

pg.

8;

2006

SIUC

Report,

pg.

8, 2005

SIUC

Report,

pg.

5.

Dr.

McLaren

states

that the

relief

Ameren

requests

for

the months

of

May

and

October

would

more

realistically

reflect

a

natural

thermal

environment

by

allowing

for

a more

gradual

shift

between

winter

and

summer

limits.

Tr.

at 91.

A

more

gradual

shift

in

temperature

would

-14-

---

provide

more opportunity

for

fish

to

acclimate

to

the

changing

temperatures

and,

possibly,

allow

the

fish

a

greater

opportunity

to

leave

higher

temperatures

to

seek

more

suitable

temperatures.

Tr.

at

197.

c)

Coffeen

Lake

Will

Continue

to

Provide

Adequate

Suitable

Habitat

At

hearing

the

Agency

asked

many

questions

regarding

upper

incipient

lethal

temperatures

(“UILT”)

for

various

fish

species,

suggesting

that

the proposed

limits

are

inappropriate

for

the

months

of

May

and

October

or

for

a

particular

species

found

in

Coffeen

Lake.

The Agency’s

argument,

however,

ignores

the

fact

that

Coffecn

Lake

is

a

large

cooling

lake

that

mitigates

heat

with

time,

depth,

and

distance,

and that

fish

seek

cooler

environs

when

necessary.

Coffeen

Lake

is

not

isothermal.

Tr.

at

156.

The

proposed

thermal

limits

of

96°F

and

102°F

apply

to

the

near-surface

temperatures

at

the

boundary

of

the

26-acre

mixing

zone.

Pet.

Exh.

11,

pg.

4-1.

Meanwhile,

the

temperatures

at

depth

and

at

distance

from

the

mixing

zone

can

be

very

much

cooler

and

available

to

provide

suitable

habitat.

The

record

shows

that

temperatures

at

depth

in

May

can

be

as

much

as

18°F cooler

than

at

the surface,

and in

October,

13°F

to

14°F

cooler

at

depth

than

at

the

surface.

Id.

Also,

water

temperatures

at

the

intake

on

the western

arm of

the

lake

can be

as

much

as

10°F

or

15°F

cooler

than

in

the discharge

zone.

Pet. Exh.

11,

pg.

2-2.

In

January,

mean

daily

water

temperature

reaches

lows

of

approximately

44°F-55°F

SIUC

has

also

noted

“striking”

water

temperature

differences

recorded

between

the

surface

and

at

depths

in the

mixing

zone.

2005

SIUC

Report,

pg.

4.

Mixing

zone

water

temperatures

were

recorded

as

usually

10°F

cooler

at

3.0 meters

than

1.5 meters.

SIUC

concluded

that

“[i]f

air

temperatures

and

humidity

are

not

excessively

high,

the

cooling

capacity

of water

within

a

meter

or

so

of

the surface

seems

to

be

such

that,

at

least

in

Coffeen

Lake,

surface

water

temperatures

are

mitigated

quickly

and

do

not

drive

temperatures

up at

lower

-15-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

depths.” Id. at

4. Thus, the

record

shows that at times

when

the water

approaches

the thermal

limits during May

and October,

temperatures in many areas and

depths in the lake would

be

in

the 80s

or lower

— well within the range of

temperatures tolerated by RIS life

stages. Pet.

Exh.

l1,pg.

4-I.

The record

confirms

that juvenile and

adult fish avoid temperatures exceeding

their

species-specific

preferences. Tr.

at

34; Pet. Exh. 11,

pg.

4-1. The record shows that largemouth

bass,

for example, respond to the

higher temperatures

by

seeking out cooler portions

of the lake

during

the

summer

months

and

migrating towards the discharge throughout

the remaining

seasons. 2000 SIUC

Report, Ch. 14,

pg.

14-13 (Fig. 14.31).

There

may

be a point under

hypothetical conditions

at

which

too much of the lake

could

become

unsuitable habitat for

fish

populations. However, Coffeen Lake

has

not reached that

point to date. The proposed limits

for

May

and

October are lower than the temperatures the

lake

has experienced in the past

and the minimal

increased

thermal loading

in May and October

is not

expected to have a

cumulative impact

on

water temperatures

or dissolved oxygen concentrations

in succeeding summer

months leading

to

habitat erosion. Ameren’s Response,

pg.

12-13. The

record confirms that

Coffeen Lake currently

supports a

healthy fishery and that the

request for

relief

during May and

October will not affect the maximum temperatures

that occur

at

the edge

of the

mixing zone

during

summer months in the lake.

d)

Fish Will Adapt to Their Unique Thermal Environment

The Agency’s

arguments

about

the proper UILT also fails

to

consider that fish

in Coffeen

Lake are

chronically exposed to warmer

temperatures

and have adapted to

this temperature

regime.

See Tr. at 150-51.

Laboratory studies

of temperature tolerance used

to

develop

UILTs

measure

rapid responses to changes in temperature.

As a

result, states Dr. McLaren,

their

use

tends to conservatively underestimate

thermal tolerance

in

the

field. Pet. Exh. 11,

pg.

4-2.

-16-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

SIUC

has

repeatedly

recognized

the

adaptability

and

thermal

tolerance

of

fish

populations

in Coffeen

Lake.

SIUC notes

there is

a

preferred

laboratory

temperature

for

largemouth

bass,

but

that the

mean

internal

body

temperatures

exceeded

the

preferred

temperature

in

July

and

August

of

1998

and

1999.

SIUC concluded

that

“[t]his

suggests

that the

preferred

temperatures

in

these

lakes

are

higher

than

those

found in

the

literature.”

2000

SIUC

Report,

Ch. 14,

pg.

14-14.

SIUC also

notes

that

the

absence

of a fish

kill during

critical

water

quality

conditions

that occurred

on

certain

dates

in

2006

“underscores

the

resilience

and

adaptability

of

fishes

to extreme

environmental

conditions

over

time.”

2007

SIUC Report,

p.

5.

Further

evidencing

the

thermal

tolerance

of largemouth

bass,

SIUC

found

that

even in

years

with

relatively

high

mean

water mixing

zone

temperatures

relative to

other years

of the

study,

largemouth

bass growth

rates

were comparable

to

the

other

years’ rates.

2005

SIUC Report,

pg.

19.

The

Board

has

also recognized

that

fish are

adaptive

to

unique site-specific

thermal

conditions.

Petition

of

Commonwealth

Edison

Co.

(ComEd)

for

an

Adjusted

Standard

from

35

Ill. Adm.

Code

302.211(d)

and

(e),

AS

96-10 (Oct.

3, 1996).

Therefore,

it is

generally

accepted

that fish species

adapt to

their

thermal

environment.

Ameren

expects

that the

current

fishery in

Coffeen

Lake

will

adapt

to and continue

to thrive under

the

requested

relief.

2.

Water

Quality

In the

Recommendation,

the

Agency

stated

a concern

about

whether

the

requested

relief

would

prolong

the stratification

period in

the lake,

thereby

promoting

the internal

loading

of

phosphorus

and

mercury

methylation

and

exacerbating

dissolved

oxygen

concentrations.

See

Rec.

at 18,

19. The

Agency’s

concerns

about

water

quality with

respect to

phosphorus,

mercury

and

dissolved

oxygen

are

unfounded.

First,

there

are no

data

that indicate

that the

proposed

modifications

to

the

thermal limits

in

May and

October

will have

a

cumulative

impact

and

- I

7-

---

exacerbate

water

quality

conditions

in

other

months

throughout

the

year.

Exh.

2,

par.

20(c).

Second,

as

demonstrated

below,

these

water

quality

parameters

are

more

dependent

on

air

deposition,

surrounding

land

uses

and

resulting

runoff

from

the

watershed

rather

than

the

thermal

effluent

from

Coffeen

Power

Station.

Third,

Coffeen

Lake

is

listed

by

the

Agency,

and

approved

by

the

United

States

Environmental

Protection

Agency

(“USEPA”)

on

October

22,

2008,

as

filly

supporting

aquatic

life.

Below

Ameren

explains

in

more

detail

how

the

intermediate

limits

Ameren

seeks

will

have

no

measurable

impact

on

water

quality

in

Coffeen

Lake.

Ameren

notes

that

the

Agency

has

made

no

effort

to

dispute

the

testimony

of

Ameren’s

experts

by

introducing

its

own

expert

testimony

on

these

issues.

a)

Dissolved

Oxygen

In

the

Recommendation,

the

Agency

seems

to

argue

that increased

heat

loading

in

May

and

October

may

have

an

adverse

effect

on

dissolved

oxygen

(“DO”)

levels

and

therefore

lead

to

erosion

of

habitat,

and ultimately

fish

kills.

Rec.

at

14-15.

The

record

shows,

however,

that

temperatures

warmer

than

those

being

proposed

have

not

adversely

affected

the

aquatic

community

during

the

summer

months.

Dr.

McLarcn

analyzed

DO

data

at

varying

depths

collected

by

SIUC

during

2000,

2001,

2003, 2004,

2005

and

2006

to

evaluate

whether

DO

cumulatively

decreased

from

May

through

October

in

Coffeen

Lake,

and

found

that

it

does

not.

Exh.

2,

par.

10.

As

discussed

above

for

water

temperature,

meteorological

conditions

can

modify

DO on

a

daily basis.

Id.

Thus,

Dr.

McLaren

concluded

that

dissolved

oxygen

concentrations

will

likely

remain

sufficient

to

sustain

the

aquatic

community

even

under

the

proposed

May

and

October

limits.

Id.;

Ameren’s

Response,

pg.

12-13.

As

it

did

with

temperature,

however,

the

Agency

argues

that

increased

loading

in

May

could have

a

cumulative

effect

on

dissolved

oxygen

levels

in

June

through

September.

An

extensive

examination

of

the

SIUC

data

with

respect

to

dissolved

oxygen

at

depth

in

segments

I

-18-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

and

2

of

Coffeen

Lake did

not

reveal

any discemable

pattern

that

oxygen

depletion

increases

as

summers

progress.

Exh.

2, par. 10;

Ameren’s

Response,

pg.

13.

This

pattern

(or lack thereof)

is

evident

in

every

year SIUC

performed

dissolved

oxygen

arid temperature

profiling.

See Exh. 2,

par.

10. The

record

simply

does

not show

that the

proposed

modification

to

thermal

limits in

May

and October

will result

in

decreased

oxygen

levels

in summer

months

or

other months

throughout

the

year.

b)

Phosphorus

The

Agency

asked

many

questions at

hearing

implying

that

the

requested

relief

for the

months

of May

and

October

would promote

the

internal

loading of

phosphorus

in Coffeen

Lake.

The

evidence of

record

indicates

otherwise.

Coffeen

Lake

is listed

by

the Agency

as impaired

for

phosphorus

for

aesthetic

quality. Illinois

Integrated

Water

Quality

Report

and

Section

303(d)

List

-

2008, App.

B-3.

After

thoroughly

reviewing

Coffeen

Lake data

gathered

by

SIUC

and

the

2007

TMDL

analysis

performed

by IEPA,

Dr. Shortelle

concludes

that

no significant

internal

loading

of

phosphorus

is occurring

in

Coffeen Lake.

Support

for this

conclusion

is the lack

of

any seasonal

trends with

regard

to phosphorus

and

chlorophyll-a.

Exh.

3,

Att.

2,

pg.

2-2. Dr.

Shortelle

explained

that

chlorophyll-a

is an

indicator

of how

much

phytoplankton

there

is

in the

lake.

Chlorophyll-a

is

produced

by

plants,

such

as phytoplankton

or

algae

in the

water,

and grow

better

with

more

nutrients

such

as phosphorus.

Tr. at 44.

Chlorophyll-a

is

produced

in the

epilimnion

where phosphorus

can

fuel primary

production.

Tr. at

246. The

impairment

for

aesthetic

quality

in Coffeen

Lake

focuses

on the epilimnetic

phosphorus.

Tr.

at

246.

An

in-depth

analysis

of

the

potential

for increased

internal

loading

of phosphorus

due

to

the

requested

change

in thermal

limits

in

May

and October

demonstrates

that at best

there would

be

1.5%

increase

in internal

phosphorus

loading

under

the

revised

thermal

standard.

Dr.

Shortelle

concludes,

however,

that this

additional

phosphorus

would

not reach

the epilimnion.

-19-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

Exh.

3,

Att.

2,

pg.

2-25.

With

no additional

phosphorus

reaching

the

epilimnion,

this

incremental

increase

would

not

contribute

to

the

lake’s

impairment

for

aesthetic

quality

because

it

could

not,

for

example,

fuel

an

algal

bloom.

Tr.

at

230.

Dr. Shortelle states

that

the

phosphorus

in Coffeen

Lake

is

primarily

coming

in

from

the

watershed

due

to

runoff

from

agricultural

operations.

Tr.

at 47;

see also

Exh.

3,

Att.

2,

pg.

2-7.

The

303(d)

listing

for

Coffeen

Lake

supports

this

conclusion

by

listing

“crop

production”

as

a

source

of the

phosphorus

impairment.

Illinois

Integrated

Water

Quality

Report

and

Section

303(d)

List

— 2008,

App.

8-3.

Overall,

Dr.

Shortelle

concluded

that only

Segments

I

and

2

would

potentially

experience

additional

days

of

stratification

during

the

months

of

May

and

October

sufficient

for

the

small

change

in

internal

loading,

but

that the

frequency

and

duration

of

stratification and

anaerobic

activity

would

not

result

in

a measurable

increase

in surface

water

phosphorus

concentrations.

Tr.

at 246;

see

also

Exh. 3,

Att.

2,

pg.

2-22.

c)

Mercury

The

Agency

also

asked

questions

at

hearing

about

whether

higher

temperatures

during

May

and

October

would

contribute

to

mercury

methylation.

While

warmer

temperatures

are one

of

many

factors

that

may

contribute

to

mercury

methylation

in

the environment,

a

dominant

factor

in

Coffeen

Lake

is

the

mass

of mercury

entering

the

lake

watershed

due

to

atmospheric

deposition.

Coffeen

Lake

is

listed

by

IEPA

as

impaired for

fish

consumption

due

to

mercury

levels.

Illinois

Integrated

Water

Quality

Report

and

Section

303(d)

List

— 2008,

App.

B-3.

Coffeen

Lake

fish,

however,

have

relatively

low

mercury

concentrations. Tr.

at

53. Largemouth

bass

in

Coffeen

Lake

rank

among

the lowest

in

mercury

concentration

among

fish

data

from

state

and

federal

studies.

Tr.

at

52;

Exh.

3,

Att.

2,

Fig.

3-2,

Table

3-1.

Mercury

is

constantly

cycled

through

a

biogeochemical cycle

in the

environment.

Exh.

3, Att.

2,

pg.

3-1.

Methylmercury

is

-20-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

the

biologically active

form

of mercury

and bioaccumulates

up

the

food

chain.

Id.

Methylation

of

mercury

in

ecosystems is affected

by multiple

parameters

such

as mercury

loadings,

nutrient

content,

pH,

oxidation-reduction

conditions,

bacterial

activity,

and

other

variables.

Id.

However,

one of

the

primary

drivers

for

mercury

concentration in

fish

tissue,

regardless of

cycling

dynamics,

is

the

quantity

of mercury

in

the watershed

(primarily

from

atmospheric

deposition). Tr.

at

53-54.

The

larger

the

watershed,

the

larger

the

potential

for mercury

to

get

into

the

lake.

Tr.

at 54.

Dr.

Shortelle

opines

that

the

primary

source

of

mercury

loading

is due

to

atmospheric

deposition.

Tr.

at

244.

IEPA

clearly

recognizes

this

fact

since

it

has cited

“atmospheric

deposition”

as

a

source

of

mercury

in

the

impairment

listing

for

Coffeen

Lake.

Illinois

Integrated

Water

Quality

Report

and

Section

303(d)

List

— 2008,

App.

B-3.

New

air

emissions

limits

will

significantly reduce

regional

mercury

loading.

Ameren

will

spend

more

than

$600

million

to

install

flue

gas

desulphurization

systems

(“scrubbers”)

on

both

of its

units

at Coffeen

Power

Station

to comply

with

new air

emission

limits.

Tr.

at

18,

80.

The

scrubber

on

one

unit

at

Coffeen

Power

Station

will

begin

to operate

at the

end of

2009,

and

the

second

scrubber

will

begin

to operate

at

the end

of

2012.

Tr.

at

254.

The

scrubbers

are designed

to

remove

SO

2

,

but

a

co-benefit

of

their

operation

is

the

removal

of

mercury

from

air emissions.

Tr.

at

254.

These

emission

limits

are

applicable

statewide

and

are

expected

to

result

in regional

mercury

load

reductions. Using

the

maximum

observed

mercury

concentration

in

largemouth

bass,

a

thirty-

three

percent

reduction

in

mercury

loading

is

necessary

to remove

the impairment

in Coffeen

Lakc.

Proportional reductions

are

expected

from

decreased

regional

atmospheric

loads

of

mercury.

Tr. at

55;

see

In

the

Matter

of:

Proposed

New

35 Ill.

Adm.

Code

225

Control

of

Emissions

from

Large

Combustion

Sources

(Mercury),

R06-25,

Testimony

of

Marcia

Willhite, at

-21-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

162-172

(Jun.

14,

2006).

Such

reductions are

expected

to,

in

turn,

reduce

the

mass

of

mercury

available

for

methylation

in

Coffeen

Lake.

In

summary,

although

the

requested

relief

may

cause

some

theoretical

changes

in

mercury

cycling,

any

effect

on

rates

of mercury

methylation

that

may

occur

would

be

very

minor

and

not

likely

result

in measurable

changes in

fish

mercury

concentrations.

Exh.

3,

Att.

2,

pg.

3-

8.

In fact,

pollution

controls

that

Ameren

will

initiate

in

a

matter

of

months

will

likely

have

an

overriding

beneficial

impact

to Coffeen

Lake

by actually

reducing

mercury

loading

due

to

air

deposition.

B.

Coffeen

Lake

Will

Continue

to

Support

a

Wide

Range

of

Recreational

Uses

Consistent

With

Good

Management

Practices

There

is no

doubt

that

Coffeen

lake

is

a

valuable

asset

to

the

State

of

Illinois

as

a

public

place

for

recreational

activities

such

as

fishing,

boating,

picnicking,

and

hunting.

Through

May

of

this

year,

approximately

30

fishing

tournaments

have

already

been

held

on

the

lake,

demonstrating

that

the

Lake

supports

excellent

gamefish

populations.

See

http://dnr.state.

il.us/lands/LandmgtJParks/R4/CFL/CFL

fishingshedule.htm.

The

Board

itself

has

recognized

that

the

addition

of heat

to

artificial cooling

lakes

from

electric

generating

plants

allows

fish

and

other

aquatic

organisms

to

grow

continually

during

the

winter,

which

is

not

usually

the

case

for

Illinois

lakes.

Cooling

Lakes,

R75-2,

slip

op.

at

22.

Even

if

unusual,

the

Board

noted,

the

phenomena

contributes

to

the recreational

value

of

an

artificial cooling

lake,

and

moreover,

can

actually

indicate

the general

environmental

quality

and

acceptability

of

an

artificial

cooling

lake.

Id.

at 22.

The

Board

reasoned

that

the

State

of Illinois

needs

general

recreational

facilities,

and

that

by

creating

these

areas,

cooling

lakes

provide

a

considerable public

benefit

to

be weighed

against

any

possible

environmental

harm.

Id.

at 23.

-22-

---

The

wide range

of recreational

uses that Coffeen Lake supports are appropriate for its

function as an

artificial

cooling lake. The lease agreement between

Ameren

and the IDNR

recognizes

that the

primary purpose of

Coffeen Lake

is

to support

the operation of Coffeen

Station as

well

as

Arneren’s

right to vary the lake’s level and temperature. Pet. Exh.

6.

The

lease

further recognizes

Ameren’s right to use

the lake for cooling water purposes

and that

public

use

shall not

conflict with that right. Id.

Accordingly,

the lease does not

allow swimming in

Coffeen Lake

and

restricts public use

of the lake

near the power

station

and

around the mixing zone.

Pet.

Exh.

6. The lease identifies

recreational areas

and restricted access

zones. Id. at 2. Areas

that

arc off limits

to public include

the intake,

spiliway, discharge, and dam.

Id.

at

2,

7. In addition

to

swimming, the original lease

executed in 1986

also

prohibits water skiing, diving,

scuba diving, windsurfing, sailboating

or

hunting in the recreational

areas of Coffeen Lake. Id. at

3.

In

1995,

the parties

executed an

amendment to the

lease that expanded the

recreational

uses of Coffeen Lake

to

include hunting

of specified wild

game, fish

management, hiking, the observation,

study or research of

soil,

plants or

animals, and other

outdoor activities

that the parties may agree are

appropriate. Id.

at

48.

Various

commenters have

stated

that they

or their members have

participated

in

recreational uses of

Coffeen Lake. Ms. Blumenshine

states she has “done hiking and bird

watching in the Coffeen

Lake Upland Management Unit . . .

.“ PC#3. Prairie Rivers Network

states that

“Coffeen Lake has

been increasingly known

by many, including members

of

Prairie

Rivers Network,

as an

outstanding recreational site;

particularly for fishing as well

a

boating,

picnicking,

bird watching,

and other nature-based activities.”

PC#2. Ms. Bates commented:

“I

visit the Coffeen

Lake

frequently

and have

friends who

boat and fish on the

lake.” PC#1. Based

-23-

---

on these facts

and assertions,

the record clearly

shows

that Coffeen Lake supports

a

wide

range

of recreational

uses and that these

uses will not be impacted

by

the requested

relief. There is no

evidence of

record to the contrary.

IV.

AMEREN

HAS

SHOWN THAT

NONE OF THE AVAILABLE

TREATMENT

ALTERNATIVES

ARE ECONOMICALLY

REASONABLE

In promulgating

a

thermal

standard, the

Board

considers

the cost and

practicality

of

eliminating

or controlling

the

thermal component

of an effluent

and the benefits to

be derived

from an effluent

source.

See

Cooling Lakes,

R75-2, slip

op.

at 2. It

is well-recognized

that

public utilities are

vital to the

social

and

economic

structure

of Illinois. The

Coffeen Power

Station plays a significant

role

in

supplying

power

to

Illinois consumers.

Ameren’s

requested

relief

is necessary for

Coffeen Power Station

to

accommodate

the increasing

demand for power

in Illinois given a variety

of

factors including

a

deregulated power

market,

new environmental

pollution control requirements,

and a developing

pattern of meteorological

conditions

resulting

in

warmer

ambient temperatures

during the

transition months of

May and October.

Coffeen Power Station

pays significant

taxes and employs

400 people. See Pet.

Exh,

5.

Ameren

has recently invested

hundreds of

millions of dollars

in installing

state

of the

art

pollution

control equipment.

Such

construction

projects employ

hundreds

of skilled, union

employees.

An

economically

viable

and

profitable power

station will

benefit not

only

the

Company but

will

also

provide a

stable

tax

base and well-paying

jobs in

one

of

the

more

rural

parts

of

the State.

Moreover, allowing Coffeen

Power

Station to operate

throughout

the year

without

having

to de-rate

or shut

down

altogether

also

provides

a benefit

to

the

retail customers

in Illinois

and throughout

the

Midwest region.

Tr. at I 8.

The Board

has

also noted

that

technologies

to

cool coal-fired

electric generating

plant

discharges to cooling

lakes are expensive.

Cooling

Lakes, R75-2, slip

op. at 8.

In fact, this

was

-24-

---

one

of

two

findings

the

Board

relied

on

in

promulgating

this

exception

for dischargers

to

artificial

cooling

lakes

as it

applied

to existing

lakes

and would

apply to

all lakes

built

in

Illinois

in the

future. Id.

A.

None

of the

investigated

Supplemental

Cooling Technologies

Are

Economically

Reasonable

Of all

of the

supplemental

cooling

technologies

Ameren

examined,

none

are

economically

reasonable

solutions that

will

allow

Coffeen

Power

Station to

run under

anticipated

operating

conditions

when

weighed

against

the

minimal impact,

if any,

to the environment

of the

requested

relief.

Ameren

retained

S&L

to

propose

and evaluate

additional

enhancements

to the

lake’s

cooling

systems.

S&L

evaluated

eight

alternative

capital

projects

designed

to

reduce

further

thermal

loading

on the

lake. See Pet.

Exh.

15. Of

these

alternatives,

the

one providing

the

best

economics

was identified:

the installation

of a

175,000

gpm cooling

towers with

a

capital

cost

of$l

8

million

dollars.

Exh. 1,

par. 9.

Ameren

analyzed

the

economic

viability

of the

175,000

gpm

cooling

tower in

comparison

to

the

alternative

of

continuing

as-is

by

using

de-rates

to

comply

with the

thermal

limits.

That

analysis,

performed

in 2006,

estimated

that it would

take approximately

11.5

years

for

the

Company

to

recover

the costs

of its investment

in the

new

cooling

tower.

Pet. Exh.

15;

Exh.

1,

par.

9.

Because

these

were

extraordinary

costs with a

long payback

period,

the Company

concluded

that these

investments,

added to the

initial investments

made

in the

cooling

basin and

existing cooling

tower,

and

other capital

funding

needs of

Ameren were

not

justified.

In

preparing

for

the hearing

in

this case,

Ameren

re-ran

its analysis

of the

helper cooling

tower with

updated

information

and assumptions.

In updating

the analysis,

two critical

assumptions

were added

into the economic

analysis:

The

future

market

prices

for power

and

the

likelihood

of

additional

costs

in the form

of

a

CO2

tax or other

compliance

cost. When

such

-25-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

considerations

are

taken

into

account,

the

costs

associated

with

the

capital investment

in

the

175,000

gpm

cooling

towers

cannot

be

recovered

before

the

equipment

itself

needs to be

replaced.

The

power

generation

industry

in Illinois

now

operates

in

a

deregulated

environment

and

as

such

capital

expenditures

are

not

subject

to

rate-based

regulation

or

recovery.

Accordingly,

capital

expenditures

must

be

supported

by

sales

of

power and

associated

power

prices

that

are

the

source

of

cash

flow

and

earnings.

Power

prices

began

a

precipitous

drop

in

July

2008

and

have

continued

to

be

depressed

during

this

prolonged

recession

that

has

resulted

in

record

job

losses,

bankruptcies

and

lay

offs.

Market

participants

expect this

trend

to

continue

over

the

next

few

years.

See

Ameren’s

Response

to

Information

Requested

During

Public

Hearing,

pg.

4.

The

original

economic

analysis

of the

175,000

gpm

cooling

tower

also

did

not

consider

the

cost

of

compliance

with

carbon

regulation.

An

energy

cost

adjustment

for

pollution

control

equipment

needed

for

compliance

with

carbon

regulation

beginning

in

2014

was

factored into

the

updated

economic

viability

analysis.

When

these

two

critical

assumptions

are

considered,

Ameren

calculated

that

the

cooling

tower

equipment

would

reach

its end

of

life

and

need

to

be

replaced

before

the

capital

investments

could

be

recovered.

As

a

result,

Ameren

cannot

consider

this

an

economically

reasonable

alternative.

B.

Continuing

to

Dc-rate

to

Meet

the

Current

Thermal

Limits

in

May

and

October

is

not

Economically

Reasonable

Operating

in

a

deregulated

market

places

additional

demands

on

power

generators.

Additionally,

operating

as

a

baseload

generator

benefits

the

consumers.

Ameren

expects

to

approach

a

90%

capacity

factor

by

2011

as

demand

continues

to

increase.

Tr.

at 63.

While

Coffeen

Power

Station

will

gain

operating

capacity,

this

increase

in

capacity

does

not

translate

to

greater heat

load

because

the

units

will

operate more

efficiently.

Tr.

at

125.

It

also

will

not

-26-

---

translate

to

more

revenue

for Ameren,

since a significant

portion of

the

gain

in operating

capacity

will be

used

to

power new

pollution

control

equipment.

Coffeen

Power

Station

currently

operates

in the high

90% capacity

factor

during

summer months

and has

for years.

Tr.

at 255.

The

expected

increase

in capacity

is to

the

annual

capacity factor,

which

mostly

includes

periods of

time

that

are

unaffected

by

the

relief Ameren

is requesting

in

this proceeding.

Tr. at

256.

The

calculated

generation

shortfall

for

the

month

of May,

considering

historical

weather

data

from

1980

through

2007,

shows

a

gradual

increase in

average

losses

over

time. For

example,

losses

went

from 12%

in 1980

to 21% in

2007. The

average

loss per year

is

16%,

which

equates to

$2,334,000

in losses,

based

on

2007

dollars, and

is

a trend

that is not

economically

reasonable

for

Ameren

to sustain.

Pet. Exh.

15,

pg.

7.

C.

Ameren’s

Requested

Modified

Thermal

Limit is

a Technically

Feasible

and

Economically

Reasonable

Method

of Controlling

the

Thermal

Effluent

Under the

Board’s

economic

analysis,

the question

is not

whether the

discharger

can

profit

from

the

installation

of a

treatment

technology

or

even whether

the discharger

can recoup

its costs.

The

standard

for the Board

to

consider

is whether

the cost

of the

treatment

technology

is

reasonable

given

the

environmental

benefit

gained from

installing

the

technology.

Heat

is

a

very

unique

pollutant,

the concentration

of which

can be

mitigated

not

just by

control

technology,

but

also

by

weather

conditions

and

the

morphology

of the receiving

water body.

It

has also

been

recognized

that in

some instances

heat

can

be

beneficial to

the

lake biota,

For

these

reasons,

a standard

analysis

comparing

costs

to the

amount

of heat kept

out

of

the water

by

various

cooling

technologies

does

not suffice.

A

case-by-case

analysis

evaluating

the

cost

to

control

the

thermal

component

of a particular

effluent

to

a

particular

waterbody

compared

to the

benefit

to

that lake

biota

is

required.

-27-

---

S&L

concluded

that

installing

the

175,000 gpm

helper

cooling

tower

will

reduce

temperatures

enough to

allow

Ameren

to

operate

during

the

months

of

May

and

October

even

under

worst-case

conditions

without

having

to

dc-rate.

However,

spending

millions

of

dollars

on

installing

the

tower

is not

expected

to

result

in any

measurable

benefit

to

aquatic

life

in

Coffeen

Lake.

Based

on

these

facts,

there

is

no

environmental

need

for

add-on

treatment

technology

such

as

the

helper

cooling tower.

As

part

of

the

alternatives

analysis,

Ameren

also

asked

S&L

to

model

the

performance

of

the

existing

cooling

system under

warmer-than-normal

summer

conditions,

but

with

the

modified

thermal

limits

being requested

in

this

proceeding.

S&L

concluded

the

proposed

alternative

May

and

October thermal

limits

would

be

able

to

accommodate

the

same

rate

of

generation

as

any

of

the

other

proposed

additional

cooling

system

modifications.

Based

on

these

results,

the

Company

concluded

that

the

substantial

additional

investment

costs necessary

to

meet

the

existing

temperature

limits

outweighed

the

marginal

benefits

to

be

gained

by

having

a

helper

cooling

tower

at

the

ready,

but

that

would

realistically

be

deployed

an

average

of

only

31

days

per

year

during

time

periods

when

market

prices

and

operating

margins

are

low.

The

Company

concluded

that

the

proposed

project

would

be

uneconomical,

particularly

when

modifying

the

thermal

limits

for

Ameren’s

thermal

effluent

during

the

months

of

May

and

October

will

have

no

measurable

negative

impact

to

the

environment

and

when

compared

to

other capital projects

that

compete

for

finite

capital

dollars

and

promise

greater

benefit per

dollar

spent.

Also

to be

factored

into

the

economic

analysis

are

the

existing

technologies

Ameren

has

recently

constructed

and

implemented

at

the

Coffeen

Power

Station.

Ameren

on

its

own

initiative

and

within

the

past

10

years,

has

undertaken

a

number

of

efforts

to

maintain

-28-

---

compliance with the current thermal

limits without having to resort to dc-rates. These

capital

projects included the

construction of a 70-acre cooling basin and a

48-cell,

200,000

gallon per

minute (gpm) cooling tower system.

Realized within the

past

10 years,

these projects totaled

$26

million in capital costs alone. Despite these efforts, Ameren has still had to de-rate

from

time to

time in the recent past during the shoulder months of May and October. At hearing, the

Board

asked how many times

Ameren

has implemented

planned

or

forced outages

since 1999

to

comply with the standards. Tr. at

75

A

chart

summarizing the economic impact of

dc-rates

to

Ameren from January 1999 through September 2007 is attached

to

the

Petition

as Exhibit

14.

Between the two

units,

the economic costs associated with

dc-rates

have amounted

to

$5.6

million.

Cooling

lakes themselves are an acceptable and effective cooling technology. Utilizing

Coffeen

Lake for

its

intended purpose

requires

no capital investment, nor does it emit any

additional

pollutants, or require

any loss

of habitat or

delay

in implementation. An

additional

cooling tower would also impose additional water consumption demands at

a

time when Ameren

has

an immediate need of an additional two million gallons

of water per day to operate new

pollution

controls

required by state law. See Tr. at

83-86.

V.

PUBLIC

COMMENTS

The Board has received two oral

and

four written public comments in this proceeding.

The

two members of the public that gave oral public comment

at

hearing, Ms. Bates and

Ms.

Blumenshine,

also

submitted written comments. Public comments, whether written

or

oral,

do

not constitute

evidence

in this

proceeding. The commenters were

not

sworn or subject to

cross

examination.

Ameren addresses each of the comments in

turn below:

A.

Ms. Mary Bates — Public Comment #1

-29-

Electronic Filing - Received, Clerk's Office, August 13, 2009

---

Ms. Mary Bates

is a resident

of

Hilisboro and is a member

of

Citizens Against

Longwall

Mining and

the

Illinois

Sierra

Club. Ms.

Bates

states she will

be

adversely affected

if the

temperature

is

allowed

to be

raised

at any

time

during the year, but

does

not explain

in

what

way

she

might

be

affected.

Ms.

Bates

is concerned

about the effect

of

activities

at

the Deer Run

Mine

in combination

with

this proposal on

lake

levels

in Coffeen Lake.

PC #1, Tr.

at 249.

Ameren

is

not familiar

or

associated

with the

mining project and

does not

believe that such

activities are

related

or

germane

to

its

requested relief.

Ameren

nonetheless

notes that this request

for

modified thermal

limits

for

the

months of

May and October will