ILLINOIS POLLUTION CONTROL BOARD

October 29,

1992

VILLAGE OF WINNETKA,

)

Petitioner,

)

v.

)

PCB 92—162

)

(Provisional Variance)

ILLINOIS ENVIRONMENTAL

)

PROTECTION AGENCY,

)

Respondent.

ORDER OF THE BOARD

(by

J.C.

Marlin):

This matter comes before the Board

on receipt of an Agency

Recommendation dated October 28,

1992.

The recommendation refers

to

a

request

from

Petitioner,

Village

of

Winnetka,

for

a

provisional

variance

for

its

Cook

County

facility

from

the

prohibition on discharge without an NPDES permit as set forth in 35

Ill.

Adm.

Code

304.141(b),

to

allow them to

use hot water

to

destroy the present infestation of zebra mussels on their inlets

and within their intake pipelines for both their water treatment

plant and power plant.

The recommended term of this provisional

variance

is

for the period

from when the Petitioner begins

the

thermal treatment process for zebra mussel control, and continuing

until the Petitioner ceases thermal treatment, but not for longer

than 45 days.

The

Agency

recommends

that

the

Board

grant

the

requested

provisional variance with specified conditions.

The Agency agrees

that the repairs are necessary.

The Agency anticipates that the

requested provisional variance would have minimal environmental

impact on the receiving

stream.

The Agency

is unaware

of any

public water supplies that the requested provisional variance would

adversely

impact.

The

Agency

maintains

that

a

grant

of

a

provisional variance would violate no federal laws.

The Agency

finds that a denial of the requested provisional variance would

create an arbitrary or unreasonable hardship on the Petitioner.

The responsibilities

of

the Agency

and the Board

in these

short—term

provisional

variances

are

different

from

the

responsibilities in standard variances.

~

Ill. Rev.

Stat. 1991,

ch.

111½,

pars. 1035(b)

&

(c).

In provisional variances it is the

responsibility of the Agency to make the technical determinations

and finding of arbitrary or unreasonable hardship.

The Board’s

responsibility is

to adopt

a

formal Order,

to assure the formal

maintenance

of

the record,

to

assure

the enforceability

of the

variance,

and

to provide notification

of the action by

a

press

release.

0 37-0095

---

2

Having

received

the

Agency

recommendation

finding

that

a

denial

of

the

requested

relief

would

impo3e

an

arbitrary

or

unreasonable

hardship,

the

Board

hereby

grants

Petitioner

a

provisional variance

from

35

Ill.

Adm.

Code

304.141(b),

on the

following conditions:

1.

The term

of this provisional variance

shall commence

when

the

Petitioner,

Village

of

Winnetka,

initiates

the

thermal

treatment process

for

zebra mussel control,

and

it

shall expire on the date the Petitioner completes the required

maintenance work,

or after

45 days have elapsed,

whichever

comes first;

2.

During the term of this provisional variance, Petitioner

shall

maintain compliance with

35

Ill.

Adm.

Code

302.507,

thermal limitations at the edge

of

a mixing zone and shall

conduct the thermal treatment process in accordance with the

procedures described in Petitioner’s variance request.

If a

temperature rise of more than 3°Fat the edge of the mixing

zone

is

detected,

the

Petitioner

shall

close

the

valve

connecting

the thermal

plant

to the intake pipe and shall

start

a

low

lift pump to draw the heated water out of the

intake pipelines into the water treatment plant.

3.

The Petitioner shall notify Robert Sulski of the Agency’s

Maywood Regional office by telephone,

at 708/531—5900, when

the thermal treatment process

begins and when that process

ends,

and the Petitioner shall confirm this notice in writing

within five days, addressed as follows:

Illinois Environmental Protection Agency

Division of Water Pollution Control

Compliance Assurance Section

2200 Churchill Road

P.O. Box 19276

Springfield, Illinois

62794—9276

Attention:

Mark P.

Books

4.

Petitioner shall monitor the lake’s water temperature as

described

in

their

October

19,

1992

provisional

variance

request

letter

and

their

October

9,

1992

letter

to

Liam

McDonnell of the Agency,

copies of which are attached.

5.

The Petitioner shall execute a copy of

a Certificate of

Acceptance of this provisional variance and forward that copy

to the Agency addressed as

is the written notice required in

the above condition;

the Petitioner

shall forward that copy

within 10 days of the date of this Order of the Board, and the

Certificate of Acceptance shall take the following form:

L~i~.)i

LJUJ

---

3

I

(We)

CERTIFICATION

hereby accept and agree

to be bound by all terms

and

conditions

of

the

Order

of

the

Pollution

Control Board in PCB 92-162, October 29,

1992.

Petitioner

Authorized Agent

Title

Date

IT IS SO ORDERED.

I,

Dorothy M.

Gunn,

Clerk of the Illinois Pollution Control

Board,

do hereby certify that the,abgye order was adopted by the

Board on the

~~‘/~‘

day of

~

,

1992,

by a vote of

________

0

37-0097

I

Control Board

---

~ARZA

1NV~ONMENTAI.

U$V1C~S,N~

Consulting

Eng~*ws

October

9,

1992

Mr

•

Liaz

NcDonn.1~

Environmental

Protection

Engineer

Illinois

~viz’or~dntal

Protection

AgeflaY

P.O.

$ox

19276

Springfield,

IL

42794—9276

Vjfla~eof

winnetke

Z.bZ~Mussel

Cont~ol

Study

Log.

~o

*3—0463

Permit

Application

Deer

Kr.

McDonnel3i

This

additional

i~formaticnon

the

winnetks

Zebra

Mussel

Permit

Application

is

sent

in

response

to

your

request

of

October 9,

1992.

bsjrat

Lag

~røaedi2.$~p

The

operating

pro4~.dursand

ssgu.neinrj

of

valve

and

pu~ip

operations

will

b4

as

listed

in

the

MEcops

of

Project

—

operating

Procedure”

sunsr~’

that

is

part

of

the application,

as

supplemented

by

y~urphons

conversations

with

Leonard

Ro3.t of

Hares.

We

trust

that

this

is sufficient to

cover

the

valve

and

pump

operating prbasdures,

We

can

submit

more

information

at

your

request.

Lake

xoaftorta~

P$oadlr.

The

thermal trsat*ent

procedure will conform with ZEPA and

NPDES

quid.iinss

for vaja

water

disoharqs

to

the

lake.

A

remote

reading thraoa.t*r

vii,

be

attaahsd

to

the

~

of

the

intake strainer of inlets and vi.l

provid, a continuous

temperature

raadif~g

to

a

boat

at the surface.

The

boat

viii be

*snned with psrsoftnel to radio

the

readings

to

personnel

°~

Shore.

A

diver

vJ.ll

be

available

a.

necessary.

These

precautions

viii

~e

taken

to

ensur.

that

the

lake

water

temperature dose f~ot

increase

by

more

than

one

degree

F’

above

the

ambient

tempak~atura

Of

the

water

•

U

a

temperature

rise

of

iWsTOwsr

~SQU~hW5C~rOI~Y,

Ohoftflr~ois5OeO843~2

III ~1

-0098

T.i:

(312)

$3i4$~

Fix: ~31k)

$3~.35~9

T*isx: 26.3640

---

Kr,

Lism

$cDonneil

October

9,

1992

Page

2

more

than

one

degz~eeis

detected,

the valve

connecting

the

thermal plant to

the intak, pipe viii

be

closed

and

a

by

lift

pump

viii be etartad to dray th.

water

out

of

the

intake

into

the

water

plant.

A cirstul control of the

slug

of

hot

water being

pumped

into

the

ir(taiee

pipe

will,

result

in cii

or

most

of

the

intake pipeline

adhiaving the desired 95-100

F’

temperature.

IJtsr

?reat*pat

a~d

~onitOri~ç

Xnao*ing

water

dri

be

monitored tor

I

water plant

basin

unsuitable

water.

flocculation and ~

necessary.

Any b~

treatment

plant

vi

based

on

approval

disposed

to

an

ap

~m into the

plant

via

the

low

lift pumps viii

urbidity,

odor,

debris,

end

organic

content.

A

will be reserved to

allow for diversion of

any

This

water will

be

treated

by

normally

usd

recipitation

chemicals

and activitad

carbon

as

sin

sediment

or

water

not

suitable for water

•

will

be

disposed

of

to

the

sanitary

sever

from

the

)fl~Dor

devatsrs.d

debris

will

be

roved

landfill.

Iumm&rv

pf

~ker~a1Iippt

?ra~isfsr0a1eu~I.atLo~

This

c*loulation

4*

based

on

a

volumetric

relationship

used

for

feasibility

purpo4.s

only.

Actual procedure

will

be

monitored

to

record

the

actual results of

the

thermal

treatment procedure.

Physical

parsasts~’s:

meter cast—iron intake

pipe

ntake

3,000 ft.

ntaks

—

6545 C?

irfac.

area

of pipeline

—

A

—

17,279

1?

Temperature

—

cr

temperature

in

pips

100’?

t

water

entering

intake

—

118’?

cat transfer (cast,iron

pipe)

~

199

ductivity

—

K

—

27

*Tu/HR/P’frr

• 20—inch

di~

•

Length

or

•Volumeof

• beterior

s~

• Lake Water

•

Desired

vat

•Tsap.

ofhi

• Costf. of

I

•

Th.ra&l

co~

1.

HutLose~$,~

(A)

x

(U)

v

(it)

3.847 x 10

BTV,1~

2.

Total

S~V’a

~q~uired

to

heat

intake

volume

Def.

8TtJ:

3

$TV

raises

1

lb at water 1T

Total

$TU’s

*

(408,405 lb H20) ~ (i0o’P’55•T)

—

l.835,X i07

0137-0099

---

Mr.

Liam

flobonnell

October

9,

3992

Page

3

3.

Rate

of

~TU?~‘ddition

Using

WinnetXa

condenser

#8;

Q*3,750

qpm

—

1.683

x

106

1TU/)~

Rate

—

(3..6$~

x

306 BTU/HR)

x (il5’F”55?)

—

1.00

X

20

4

Time

to

heat lintake

water to

100’,

(assumeC

oon~rol

valve

is

unthrottled

at

power

plant)

Actual

~TU’s

added

to intake

1.00

)~

10~

1.547 x 10

—

9.54

~

307 it’ø~~

1838Jx 10~OTU

+

984

X 10~ITUIMR

10.117

im

or

1,1

KIN

In

actual

case

th4

control

v*lves will be

throttled

to

control

hot

water

flow,

ai~da

much

greater

time

of

heating

is

expected.

In s~sry,

we

ka~eprovided

the

additional

information

that

You

requested.

If

yo~hay,

any

questions pleas,

call,

me

or. John

Schaefer

(312)

*3*”3$36,

otherwise we await

the

issuance

of

a

permit

to

proocad

Iwith

the

thermal

treatment

of the Winnetka

intake

pipeline.

V

truly

yours,

A

41~~ecnard

1. Molt,

P.Z.

(77

Project

Manager

LLM/ksb

cc:

Kr.

Bryan

PIc~nturft,wthn.tka

0137-0100

---

I

—

—~

ENVIRONMENTAL SE~VtCE

S. INC.

Co~swtsnp

Ergirieers

October

19,

1992

Illinois Environmental

Protection Agency

Division

of Water Pollution

Control

~

~CEVED

2200

ChLtrchill

Road

~

MiurY~CS

$~

P.O. Box

19276

Springfield,

IL

62794.9276

OCT

2

2 ¶992

Attention:

Mr.

Mark T. Books

Envtrcnment~i

Protection Agt~’lcY

S1’ATE

OF ILLINOIS

RE:

Request

for

Provisional

Variance

for

Zebra

Mussel Control

NPDES Permit

Application

No, IL

0002.~M

~EPAPublic

Water Supply

Log

No.

93.0463

Gentlemen:

We are submitting

an application pursuant to Section

180.202 of the procedures and

criteria

for

reviewing applicauons

for provisional

variances on

behalf

of

the

Village

of Winnetka.

illinois.

The

lake intakes serving

the Village ofWinzietka water treatment plant and thermal

electric

power

plant

are

infested

with

zebra

mussels.

Continued

growth

of

mussels

currently

attached

to

inlets

arid within the

intake

pipelines will

result in

possible

clogging

of these

intakes which would

result

in resthetion to

or

loss

of

the

village

water

supply.

This would

threaten the

health, business and

fire protection of

the

Village

of Winnetka

and

the

Village

01

Northfield.

This application requests

permission

from

the State of Illinois Pollution Control

Board

and

the

Illinois

Environmental

Protection Agency

to destroy

the present infestation

of zebra

mussels

by

immediate

hot

water

treatment using existing

water

plant

and

therrrial

power

plant

facilities and

intake

piping.

Allowing

the hot water

to ~ow

born

the

thermal

plant

into the

intake pipelines and

our

to

the lake end

of these ppes

would

kill the zebra

m’j$$cls

and

provide

relief

from

this

threat

for

several

months

to one year.

A

current appilcati

on for a NPDES permit when approved

would

then

allow

the

Village

to apply

thermal

treatment

on

a

permanent

basis,

most

probably one

or

twice

a year.

Sears T3wer

233 Sot~rn

W1CKPr Dnve

ChiC&Qo,

Hir~Ois

eoeoe-e302

~

i~12~

531•3800

~ax:

~3~2$3~-3999

T.tex: 25.3540

0137-0101

---

Illinois Environmental Protection Agency

October

19.

1992

Page

2

Alternauve methods of zebra mussel control would either involve chemical treatment

with

a

greater potential

envixonniental

impact~or

could

not

be

accomplished

early enough

to

provide protectionwithin

the

necessary rime frame

and would

entail a cost of approximately

S500,000.

We

have

addressed

the requirements

of Section

180.202

paragraph b) as

follows:

1)

The

Village of Winnetka

proposes

to

perform thermal

treatment of their two

raw water intakes prior

to issuance

of the

NPDES permit.

This

provisional

variance

would

allow

the operation

to be completed

this

fall

in lieu

~f

the

pending NPDES permit application received

by the IEPA Industrial Division

on

February

21,

1992.

The

NPDES

application

will

conform

with

.Lll

applicable

regulations

listed in the

LEPA Water Quality

Standards.

2)

The

Village’s

facilities

consist

of a water treatment plant

and

electric

power

plant

located on Lake Michigan in

the

Village

of

Winnetka.

The variance

is

requested to

allow thermal treatment

of

two raw water

intakà

pipelines

for

zebra

mussel controL

The treatment

plant

supplies water to all

Winnerka and

Northfield residents while the

power plant

generates

power to

supplement

power supplied by Commonwealth Edison and purchased from

the rnunicipa

I

grid

to meet

the

Village’s electrical

needs.

The

3000

ft

long 20•inch

imalce

exclusively

supplies raw water for the water treatment

plant.

The

1200

ft long

60-inch intake

supplies condenser cooling water for the

electric power pitint

and

branches

to

the

water

treatment

plant

via

a

20-inch pipe

in

order

to

supplement

the

main

20-inch

intake

pipe

supply

during

high

periods

or

demand,

3&4)

The

Village

listed,

in their NPDES Permit

.~ppilcatiorr.condenser

Cooling

water

discharges

of

7,920,000

gal/day (5,500gpm) backfeeding

throughthe 20.

inch intake and

18,288,000 gal/day (12,700

gpm) backfeeding through the 60-

Inch intake.

104~h

Inlike

During

the

thermal treatment operation,

the

most

extreme

case

ofthe thermal

process

would

be

pwnplng

100W

maximum

temperature

recirculated

raw

water

at

a rate of

5,500 gpm

for a 4

hour time period.

The total volume

of

hot water

discharged would be

176,500 cubic

feet

that would mix

with

ambient

lake water creating a mixing zone

near the intake iftiet strainer.

‘The

resultant

maximum

mixing

zone would have a córte

shaped dispersion with a

maximum

~

ul

~i

-0102

---

Illinois

Environmental

Protection Agency

October

19,

1992

Page

3

radius of 400 feet based on

lake water temperature of 52°F. The lake water

temperature at the edge of the mixing zone would

be

increased

by

no more

than

3°F.

The actual

operation would

be

performed

at a lower discharge rate

by

throttling

control valves

on

shore

with

the

mixing

zone

expected to

be

closer

to

200

ft in radius.

~O.Inek

Intake

During the

most

extreme

case of the

thermal

process for

the

60-inch inta~ke

the

Village

would

be dischai~ging100°F

maximum

temperature

recirculated

raw

water

at

the

rate of 12,700

gpmn

for

a

4

hour time

period.

The

total

volume

of hot water

discharged would be

407,500 cubic feet

that

would

mix

with

ambient

lake

water

creating a

mixing

zone near

the

intake

inlet

cones.

The

resultant

mixing

zone

would

have

a

cone

shaped dispersion

with

a

maximum

radius of

700

feet

based

on

lake water

temperature

of 52°F. The

lake

water temperature at the

edge of the mixing

zone would

be increased

by..

no more than 3°F.

LikewIse, the

actual operation would be

performed at

a

lower

discharge

rate by throttling control

valves on shore with the

mixing

zone

expected

to be

closer to

400 feet in

radius.

5)

All operations will be

within

the

limits

established in the

IEPA Water Quality

Standard regulations, as listed in the NPDES permit application submitted

to

the

IEPA.

All

requirements of

the

IEPA Public Water Supply Division

wit!.

be

met

with

regards

to

treating the

resulting

hot

water

after

the

thermal

treatment

operation

is completed. Theta will be

oe ofi.cs on

the

VilIages

drinking waxer supply.

6)

The

thermal discharge will be limited so

only enough

bat

water as

is

necessary

to kill the adult zebra msasel

~

fr~

~~4ntskes,

Water between 95°F

to

below

100°Fwill

be

used

for

*

period

of approximately four

hours

to

provide an assured kill of

the mussels.

The

process will

be monitored by use

of a remote reading thermometer attached to the

intake

inlet (the

point of

hot water discharge) by a diver

and read at

the

surface by personnel

in a boat

as described

previously

so

TEPA.

Temperature

will

also

be monitored

at

various

depths

and

locadon4

In the

lake sw-rounding the

point of

discharge

and

communicated

to the

shore where

valves

will be operated to maintain

the

desired

temperature within

the

required

range

and to minimize

the thermal

effect

in

the

Lake.

0137-0103

---

illinois

Environmental

Protection Agency

October

19,

1992

Page

4

The warmer

water

will rise

sway

from the

point of discharge and

the

effect

of

hot

water on

and near the lake bottom will be

minir~i1

We

expect

little

or no effect on

aquatic life other then zebra

mussels inside the

plant intakes.

7)

The Village

has

applied for

a

NPDES permit

for thermal

discharge

at

the

plant

intake

inlets~

It

is

not.expected

this

permit will

be

issued

in time to

allow thermal treatment this

fall.

Continued

growth

of

mussels

currently attached to

inlets and within the

intake

pipelines

will

result

in possible

clogging

of these intakes which would

resuh

in restriction to or loss of the Village water

supply.

This would

threaten

the

health,

business

and fire

protection of

the

Villages.

Alternative

methods

of zebra

mussel control would either involve

chemical

treatment with a

greaser

potential

environmental

impact;

or could

no:

be

accomplished

early enough to

provide protection

within the necessary time

frame and would entail

a

cost of approximately

S500,000.

8)

When the pending ~PDES

permit Is

approved; which

Is expected this winter~

the Village will be able to apply the thermal method of controlling zebra

mussels

once

or twice

a

year using

the

same environmentally sound method

to be used on

the trial

one

tune

basis

requested In this variance,

9)

Since

all

thermal

treatment

operations

will

comply

with

the

required

regulations

governing

the

1EPA

NPDES

permit

application,

no

other

alternatives

have

been

investigated

for the

thernial backwashing

of

the

intake

pipelines.

The

Village

could

consider alternate

hot water

treatment

options

such

as

Installation

of

small diameter hot water lines within the Intake

pipe thatwould

add

hot

water

near

the

intake

inlet,

or

hot

water

injection

via

a

heat

exchanger and pumps on &hore to provide hot

water. The option ofconveying

a

chlorine solution

to

the Intake Inlets would cost approximately

$500,000.

Other

options are

not applicable since the

proposed operation complies with

the IEPA regulations.

The

provisional

vana_nce is~dd

to allow

the Village

to

proceed with the

thermal treatment

operation this fall

in

lieu

of the

pending NPDES

permit

application.

An “unreasonable hardship” exists in this case as described in 7)

above.

0137-0104

---

Illinois

Environmental Protection Agency

October

19,

1992

Page

5

10)

The

variance

is requested to

perform

the

planned

operation in

two

(2) four

hour

treatments

in

one

day

or

two

(2)

four

hour

treatments

on

successive

days.

We arc

requesting

the full

45

days allowed, to be certain the

operation

can be completed with Lake Michigan working

limitations.

When the

NPDES

permit

application

is

approved,

the work will

be

accomplished under

that

permit.

11)

The

Village

has

riot

been

granted

any

provisional

variances

within

the

calendar year.

12)

The

Village’s NPDES

permit

application

was

received

by

the

LEPA

Ofl

February 21,

1992.

The application is pending

approval

based

on the

IEPA

issuing

the 30-day public notice

period, the Village answering

any comments

received,

and

the IEPA issuing

the

permit.

The approved permit

is not

anticipated to be iuued until mid

December

or later

under

normal application

procedures.

Lake temperatures will then be

lower (34P) and

the

process

Will

be

virtually

Impossible.

The

Village

will

be

forwarding

some

additional

information

as

required

to

the

ZEPA

Industrial

Division

so

that

the

application can

be

evaluated and a public notice

issued.

13)

No

other

matters

are

before

the

Board

in

the

behalf

of

the

Village

of

Winnerka,

We

believe

the

strong potential

for danger to

the

public

water

supply and

the

thermal

electric power plant justifies a provisional

variance

be

Issued on

a one time basism

If

additional explanation or information is required

please

contact myself

at (312) 831.3813

(FAX-

312-831-3999) or Mr.

John Schaefer at

(312)

831.3836.

We

would be

pleased to

discuss this application at your

convenience.

We await your

prompt

action in

issuance of

the Provisional Varia~cc.

Very truly yours,

~~HoIt,&

/—~

Section

Head/Environmental

Design

LLH/se

~4I~

Uft~$I

0137-0105