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BEFORE

TEE

ILLINOIS POLLUTION CONTROL

BOA1~RKSOFRCE

JUN

1

8

2003

DYNEGY MIDWEST

GENERATION, INC.,

(BALDWIN POWER STATION)

ILLINOiS ENVIRONMENTAL

Respondent

Dorothy Gunn. Clerk

illinois Pollution Control Board

James R. Thompson Center, Suite 11-500

100

West Randolph Street

Chicago, IL 60601

STATE OF IWNOIS

)

Pollution Control Board

)

)

)

)

PCBO3-

)

(Provisional Variance)

)

)

)

)

Brett J. Marshall

Water Programs Group Leader

Dynegy Midwest Generation,

Inc.

2828 North Monroe Street

Decatur, Illinois

62526-3269

Please takenotice that I havetoday filedwith the Office ofthe Clerk ofthe Illinois Pollution

Control Board

the

original

and

nine

(9)

copies

of the

PROVISIONAL VARIANCE

RECOMMENDATION ofthe Illinois Environmental Protection Agency, a copyofwhich

is served upon you.

ILLINOIS ENVIRONMENTAL PROTECTION AGENCY

By:CD~rt~LQ~AP’

Deborah J.

illiams

Assistant Counsel

Division ofLegal Counsel

Date:

June 18, 2003

Illinois Environmental Protection Agency

1021 North Grand Avenue East

P.O. Box 19276

Springfield, IL 62794-9276

21.7/782-5544

TMIS FILING

IS SUBMITTEfl

ON RECYCLED

FAFER

/1

NOTICE

---

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BEFORE THE

ILLINOIS POLLUTION CONTROL ~

JUN

18

2003

IWNEGY MIDWEST GENERATION, INC.,

~

STATE OF

ILLINOIS

(BALDWIN

POWER STATION)

Pollution

Control Board

Petitioner,

)

v.

)

PCB 03-

)

(Provisional

Variance)

ILLINOIS ENVIRONMENTAL

)

PROTECTION AGENCY,

)

)

Respondent.

)

ILLINOIS EPA RECOMMENDATION

The Illinois Environmental Protection Agency (“Illinois EPA”)recommends that the

requested provisional variance be granted subjectto the conditions set forth in paragraphten

(10) below.

ACTION MUST BE

TAKEN BY THE ILLINOIS POLLUTION CONTROL

BOARD

(“BOARD”)

WITHIN

2

DAYS

OF

NOTIFICATION

OF

THIS

RECOMMENDATION FROM THE ILLINOIS EPA.

1.

On

June

12,

2003,

the Illinois

EPA received a

request for a provisional

variance

from Dynegy Midwest

Generation-Baldwin Power

Station

(“Petitioner”).

The

provisional variance request letter is attached and incorporated as Exhibit A.

Petitioner is

requesting a provisional

variance to allow temporary relief from the total suspended solids

(“TSS”) effluent concentration limits ofOutfall 001 during the dredgingofthe secondarycell

ofthe ashpond system.

2.

Petitioner

owns

and

operates a

coal-fired generating station

located near

Baldwin, Illinois in St.

Clair and Randolph Counties.

The station is designed to provide a

maximum

generating

capacity

of 1800

megawatts.

Petitioner describes the

ash pond

---

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wastewater

treatment

system

as,

“The ash pond

system

discharges approximately

20~6

milliongallons ofwastewater(average flow) per day.

Ofthis total, approximately 60 percent

consists of fly ash sluice water and 40 percent bottom

ash sluIce water.

Each discharge is

routedto its separate ash disposal cell before combining in the secondary pond.

The mixed

fly and bottom ash waters then enter a final clarification (tertiary) pond prior to entering a

channel, which discharges to the Kaskaskia River,”

Exhibit A at 2.

Petitioner is presently

required by its National

Pollutant Discharge Elimination System (“NPDES”) Permit No.

1L0000043

to

meet TSS effluent limits of 15

mg/i (monthly average)

and

30

mg/I (daily

maximum).

3.

In describingtheneed forprovisional variance, Petitionerstates, “Initially

it

was believed

that higher than average

flows through the ash pond were causing the TSS

exceedences.

It

wasn’t

until

after the

flows

returned to

nOminal

arid

the

exceedences

continued, that itwas discovered that only 1-2 feet ofwaterwas available forsettling, which

is

not

sufficient

for ash

clarification.”

Exhibit

A

at

1.

The

Petitioner

further states,

“Baldwin

Power Station believes that immediate dredging ofthe secondary pond must be

initiated before flows through the ponds increase again, which would re-suspend evenmore

ash, resulting in higherTSS concentrations at the ash pond discharge.”

Exhibit A at 2.

4.

Petitioner addresses three alternative methods for compliance. The first two

alternatives ofstoring wastewateron-site and filtration aretechnicallynot feasible.

Thethird

alternative

of

ceasing plant operations would be extremely burdensome.

The Illinois EPA

agrees with the Petitioner that no

other technically feasible

and economically reasonable

alternative is knownthat can insure compliance with the NPDES permit while repairs are

2

---

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being completed.

5.

The Petitioner has indicated, and the Illinois EPA concurs, that denial ofthe

provisional

variance request would impose an arbitrary and unreasonable hardship on the

Petitioner.

6.

The environmental impact on the receiving strean~caused

by this variance

request is expected to be minimal.

7.

There are no federal lawsthat would preclude the granting ofthis provisional

variance.

8.

,.

The

Illinois

EPA believes

that no

public

water supply will be

adversely

affected by grantingthis provisional variance.

9.

The Petitioner has submitted no provisional variancerequests to the illinois

EPA in

calendar year

2003.

Baldwin

Power Station

was

granted

a

45-day provisional

variance for TSS effluent limitations from the ashpond system on September 2, 2002 (PCB

03-27).

10.

The Illinois EPA recommends that the Petitionerbe granted a variance from

35111. Adm.

Code

304,141(a) and the effluent limits inNPDES Permit No. 1L000004 as they

apply to total suspended solids for Outfall 001, subject to the following conditions:

a.

This variance shall begin June 16, 2003, and continue forforty-five

(45)

days from

that date or until completion ofthe project, whichever occurs earlier.

b.

During the variance period, the

Petitioner

shall meet

the monthly

average effluent concentration limits of50 mg/I for TSS.

c.

Petitioner shallcomplete the dredging and repair related work on the

3

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secondary cell ofits ash pond system as e~peditious1y

as possible.

During the provisional

variance period, the Petitioner shall operate the facility in such a manner so as to produce the

best effluent possible.

d.

Petitionershall continue to monitor and maintain compliance with all

other parameters and conditions specified in NPDES Permit No

ILO022403.

e.

Petitioner shallnotify Barb Conner ofthe Illinois EPA by telephoneat

217/782-9720, when repairs on the wastewater treatment system are completed.

Written

confirmation shall be sent within five

(5)

days to the following address:

Illinois Environmental Protection Agency

Bureau ofWater, Compliance Assurance Section

1021 North Grand Ave. East

P.O.

Box 19276

Springfield, Illinois 62794-9276

Attn: Barb Conner

f.

Within ten (10) days of the date ofthe Board’s order,

the Petitioner

shall execute a Certificate ofAcceptance and agreementwhich shallbe sent to Barb Conner

at the addresg indicated above.

ILlINOIS

ENVIRONMENTAL PROTECTION AGENCY

Date: June 18. 2003

1021

North Grand Ave. East

P.O. Box

19276

Springfield, Illinois 62794-9276

217/782-5544

Assistant Counsel

Division ofLegal Counsel

4

---

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Exhibit A

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Dynegy M~dwe~

~eneration,n~.

~N

1

r

2623

North

Monroe street

~

‘‘

)

Decatur, IIIino~sG~26-3269

~

~

Junel2,2003

Mr.

MUce Garretson, Manager

DYN EGY

Compliance Assurance Section

Division of Water Pollution control

Illinois Environmental

Protection Agency

P.O. Box 19276

Springfield, IL

62794-9276

Re:

Baldwin

Power Plant

NPDES Permit No.

110000043

Provisional Variance Request

Dear Mr. Garretson:

I.

Currently Applicable Regulations and Permit Requirements

In

accordance

with

Title

IX,

Section

35,

Subsection

(b) of

the

Illinois

Environmental

Protection

Act;

Part

160,

Chapter

2,

Subtitle

A,

Title

35

of

the

IAC;

Procedures

and

Criteria for Reviewing Applications for Provisional Variances; and Title 40 of the Code

of

Federal

Regulations,

Protection

of the

Environment,

Part

122.41

(n),

Dynegy

Midwest

Generation

(DMG)

requests

that

a

provisional

variance

be

granted

from

the

daily

maximum

and

monthly average total

suspended solids (TSS)

effluent limitations for the

ash

pond

discharge

(outfall

001)

at

Baldwin

Power

Station.

The

power

plant

is

authorized

to

discharge

wastewaters

under

the

authority

of

NPDES

Permit

No,

1L0000043, which was issued on January 2, 1998.

The

purpose of

the

provisional

variance

is

to

provide

temporary

relief

from

the

TSS

effluent

limits

to

allow

internal

maintenance-related

work

to

be

conducted

in

the

secondary

cell

of

Baldwin

Power

Station’s

ash

pond

system.

Over

the

past

several

months,

the ash

pond

system

at Baldwin Power Station

has

had

difficulty meeting

TSS

effluent limitations.

In an attempt to solve this problem,

a portion of

thesecondary pond

will

be dredged immediately and settling capacity will be restored.

Initially

it

was

believed

that

higher

than

average

flows

through

the

ash

pond

were

causing the TSS exceedences.

It wasn’t until after the flows returned to normal and the

exceedences continued, that it was discovered that only 1-2 feet of water was available

for settling,

which

is

not

sufficient for

ash clarification.

Additional

TSS

samples were

collected

from

the

bottom

ash fieJd,

the

fly

ash field,

the

secondary pond

(fly ash

and

bottom

ash

combine

at

this

point),

and

the

tertiary

pond.

Through

this

sampling

program,

it was discovered the

effluent from the fly

ash

pond and

the effluent from

the

bottom

ash field

would meet

effluent limitations if the compliance sampling

points were

located

in

these

individual

cells.

However,

when

the

two

effluents

combine

in

the

---

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Page Two

secondary pond

the

TSS

concentrations increase.

The

reason for the TSS

increase

is

because

flow through

the

secondary

pond

is

re-suspending

previously

deposited

ash

and

carrying

it

into the

tertiary

pond.

Baldwin

Power Station

believes

that

immediate

dredging

of

the

secondary

pond

must

be

initiated

before

flows

through

the

ponds

increase

again,

which

would

re-suspend

even

more

ash,

resulting

in

higher

TSS

concentrations

at the ash

pond discharge.

During the

period of the

provisional

variance,

DMG

is requesting that the current effluent

limitations for total suspended solids of 15

mg/I for a 30-day monthly average

be raised

to

50

mg/I

arid

the

daily

maximum

limit

be

eliminated.

The

provisional

variance

is

needed to allow dredging to be completed

in

the southern-most portion of the secondary

pond.

Prior

experience

from

dredging

operations

has

shown

that

Baldwin

Power

Station

will

need

the

requested

provisional

variance

concentrations

to

ensure

cornplia nce.

II.

Description of business Activity

The

Baldwin

Power

Station

is

a

coal-fired

generating

station

located

near

Baldwin,

Illinois

in

St

Clair and

Randolph

counties.

Three generating

units provide

a

maximum

capacity of,1 680 megawatts.

Ill.

Current Wastewater Flows, Pollutant Loads,

and Treated

Effluent Quality

The

ash

pond

system

discharges

approximately

20.6

million

gallons

of

wastewater

(average flow) per day.

Of this total, approximately 60 percent consists of fly ash sluice

water and 40 percent bottom ash

sluice water.

Each discharge

is routed to its separate

ash

disposal

cell

before

combining

in

the

secondary pond.

The

mixed

fly

and

bottom

ash

waters

then

enter

a

final

clarification

(tertiary)

pond

prior

to

entering

a

channel

which discharges to the Kaskaskia River (Attachments

1).

IV.

Environmental Impact Assessment

DMG

believes

that

the

impact

of the

somewhat

elevated

TSS

concentrations

to

the

Kaskaskia will

be

negligible

due

to

the

relatively

low

ratio

of discharge

from

the

ash

pond

system

(31.9

cfs) compared

to

current river flows.

According to the

Illinois

State

Water

Survey,

estimated

flows

at

the

Venedy

gauging

station

above

Baldwin

Power

Station’s river intake are

2130 cfs.

V.

Potential Hardship

No immediate, readily-implementable

alternative for complying with

the

ash pond outfall

TSS

limitations

is

available,

other

than

ceasing

plant

operations.

Ceasing

plant

operations

would

impose

an

arbitrary

and

unreasonable

hardship

on

the

station

and

DMG.

The

purpose of the

dredging

is

to

immediately

restore

compliance

in

the

ash

pond

system

and

to

prevent

future

TSS

violations

from

occurring.

This

provisional

variance would

allow expedited

dredging

while maintaining

station

operation.

Baldwin

Power Station

is

very

committed to

returning

the

ash

pond

system

to

compliance as

soon as possible.

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Page Three

VI.

Proposal

According to the

results of the

ash

pond depth

survey and

the additional

TSS samples

that were collected

in

the

individual cells, the secondary pond

is the probable source

of

elevated

TSS.

This

proposed

maintenance-related

work

activity will

begin

during

the

third week of June

and is estimated to be completed around

late July or early August.

VII.

Alternate

Methods of Maintaining Compliance with Permit Limits During

Period of

Provisional Variance

DMG

has

considered,

and

rejected,

the

following

alternative

means

for

maintaining

compliance with the

Plant’s NPDES permit during this project:

A.

Ceasing Plant Operations

This

option

would

entail

shutting

down

the

plant

entirely,

which

obviously

cannot

be done due

to the

need for generating

electricity during the summer

months.

The cost to the company to shut down the plant would be extremely

burdensome,

as

it

would

be

necessary

to

purchase

electricity

from

other

utilities.

B.

Storing

Wastewater. On-site

It

is possible to store some ash sluice water for

a

number of days,

however,

it

is not possible to store wastewater for the entire projected time period.

C.

Filtration

The

plant

is

not

aware

of

any

portable

filtration

equipment

that

could

be

brought on-site to handle almost 20

MGD.

Smaller filtration

equipment would

clog quickly and not be able to

handle the significant volume.

VIII,

Variance Period

A

provisional

variance authorizing

the

release

of ash

pond

effluents

in

excess

of the

TSS

limit is requested for June, 2003 and extending for 45 days.

IX.

Other Variances

Baldwin Power Station was granted a 45-day Provisional Variance (PCB

03-27) for TSS

effluent

limitations

from

the

ash

pond

system.

This

provisional

variance

was

issued

September 2, 2002 and allowed dredging of the

ash pond system to be performed.

---

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Page Four

X.

Current NPDES Permit Status

The

existing

NPDES

permit

for

the

plant

was

issued

January

2,

1998

and

has

an

expiration

date of January

31,

2003.

An

application

for renewing

the

NPDES

permit

was

submitted

on July 31, 2002 and a final permit is expected later this year.

XI.

Activities before the

Illinois Pollution Control Board

At this

time,

DMG

has

no

other requests before

the Pollution

Control

Board,

nor does

the IPCB

have any orders

pending at this plant.

XII.

Conclusion

Baldwin

Power Station

is

committed to

minimizing

any adverse

environmental

effects

during

the

provisional

variance

period

by efficiently managing

the

remaining

ash

pond

cells

still

in

operation.

DMG

believes

that

should

the

provisional

variance

not

be

granted,

the

result would

be

TSS

noncompliance

in

the

ash

pond

effluent during

the

period

work,

which

is

occurring

in

the

secondary

pond.

The

Baldwin

Power

Station

believes

it is critically important that the dredging begin immediately to prevent ash from

carrying through

the

secondary cell and accumulating in

the tertiary cell,

elevating

TSS

concentrations even

more.

Should

you

need

additional

information

regarding

this

provisional

variance

.

request,

please contact me at 2171876-3934.

Sincerely,

Brett J.

Marshall

Water Programs Group Leader

Attachment

---

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11

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=

~.

—

—

—

.

-

—

—

—

!~SECONDA

POND

I!.’

DISCHARGE

TO

KASKASKIA

Baldwin

Power

Plant

Ash Pond System,

LEGEND

FLY

ASH

____

BOTTOM

ASH

~

COMSINED

~

BOTTON

&FLY

BOTTOM AS~

RIVER

ASH

7

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STATE

COUNTY OF SANGAMON

)

)

)

RECEIVED

CLERK’S

OFFICE

JUN

18

2003

STATE

OF IWNOIS

Pollution

Control

Board

PROOF OF SERVICI~

I, the undersigned, on oath statethat I have served the attached

PROVISIONAL

VARIANCE upon the persons to whom it is directed, by placing a copy in an envelope

addressed to:

Ms. Dorothy M. Gunn, Clerk

Illinois Pollution Control Board

James R.

Thompson Center

100 West Randolph St. Suite 11-500

Chicago, Illinois 60601

(FAX

and OVERNIGHT MAIL)

Brett J. Marshall

Water Programs Group Leader

Dynegy Midwest Generation, Inc.

2828 North Monroe Street

Decatur, Illinois 62526-3269

(FIRST CLASS MAIL)

and mailing it from Springfield, illinois on June

18,

2003,

with sufficient postage affixed

as indicated above.

SUBSCRIBED

AND

SWORN TO BEFORE ME

this J~ay

ofJune, 2003

•~B)

~

Notary Public

OFFICIAL

SEAL

BRENDA

BOEHNER

~

NOTARY

PUBL~,STATE

OF

ILLINOIS,

?MY

COMMIssION

~XPlREs

flT4.2m~Ø5?

THIS FILING IS

SUBMrTTED ON RECYCLED PAPER

TOTRIL_ P.13