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r*r*C

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EEF'ORE

THE

ILLINOIS

POLLUTION

CONTNOI

BOARD

CITY

OF

ROCK

ISLAND.

Petitioner,

v.

iLLINOTS

ENVIRONMENTAL

PROTECTION

AGENCY.

Respondent.

PCB

9S-

IbL!

(VARIANCE)

*NE6E1VEF

CLFHi{3

OFFICE

JUN

-

u

1$98

,.*..3+ffif

SJnliH

3P'3"qe

NOTICE

OT'}-ILING

TO:

Dorothy

M.

Gunn,

Clerk

Illinois

Pollution

Corrtrol

Boarcl

100

West

Randolph

Street

-

I

lth

Floor

Chicago,

IL

60601

Chuck

Gunnarson

Assistant

Counsel

illinois

Environmental

protection

Agency

Division

of Legal

Counsel

l02l

North

Grand

Avemre

East

Springfield,

IL

62794-927

6

N4ary

A.

Gade,

Director

Illinois

Environmental

protection

Agency

l02l

North

Grand

Avenue

East

Springfield,

Il-

62794-9276

o

PI-EASE

TAKE

NolrcE

that

on

June

2,

1998,

we

filed

with

the

Clerk

of

the

pollution

Conirol

Board

Board

a

a

Petition

Petitinn

for

fnr

variance'

Vqrio.^a

a

4

copy

^^nr,

of

^c.,,L:^r-

which

i-

is

attached

--.

i , r

hereto

and

servecl

uoon

,oui

One

of I

Roy

M.

Harsch

Thomas

A.

I-Iamilton

(only

admitred

in

Ohio)

GARDNER,

CARTON

& DOUGLAS

321

North

Clark

Street -

Suite

3400

Chicago,

Illinois

60610

This

Filing

Is

Submitted

On

Recycled

pap,er

J

o

I

---

o

o

o

o

o

c

a

o

D

BEFORE

TIIE

ILLINOIS

PCLLUTION

CONTROL

BOARD-***

CITY

OF

ROCK

ISLAND.

Petitioner.

v.

ILLANOIS

ENVIRONMENTAL

PROTECTION

AGENCY.

)

)

)

)

PCB

e8-1611

)

(VARTANCE)

)

)

)

)

)

ryt'Sgygl5"'99llt

Respondent.

PETITION

F'OR

VARIANCE

The

City

of Rock

Island ('ucity"),

through

its

attorneys,

hereby petitions

the

Board

for

a

variance

from

35 lll.

Adm.

Code

$

306.305 (d)

and

an exception

approved

thereunder

by

the

Board

on

May

9,1986 ("Exception")

to

the

extent

the rule

as modified

by

the

Exception

requires

that

the

City

operate

its

main

treatment

plant

at

a maximum

flc.v

leve!

of

l6

million gallons

per

day

("MGD").

BACKGROTTND

On

December

26, 1985,

the

City

and

the

Illinois

Environnental

protection

Agency

("Illinois

EPA")

filed

a

Joint

Petition

for

Exception

seeking

relief

from

the

requirements

of

35

Ill'

Adm.

Code

$

306.305

(a)

and (b)

to

construct

and

operate

certain

combined

sewer

overflow

("cso")

transport

and

treatment

fbcilities.

(cxhibit

l).

on May

g,

lgg6,

the

Illinois

pollution

control

Board granted

the

city

and

Illinois

EPA's

Joint

Petition

for

Exception.

(Exhibit

2).

The

City

requests

a variance

because

a

condition

of the

Exception

requires

the

City's

main

treatment

plant

to

have

a

l6

MGD

maximum

flow

level,

when

its

actual

maximum

flow

level

is

12.

MGD.

More

specifically,

the

Board

adopted

by

reference

Paragraphs

14,

15

and

lf

of

the

Joini

Petition

for

Exception

in which

the

city

agreed

to perform

modificatio's

in

order

to

obtain

the

I

CLEi'KJS

OFFICE

JUN

-

z

1998

---

I

o

Illinois

EPA's

support

for

the

Joint

Petition.

At

Paragraph

15

of

the

Joint

petition,

the

modifications

were

descrilied

as "thc

construction

of

head

works

improvernents

to

allow

operation

of

the

treatment

plant

at

the

design

maximum

flow

level

of

16

million

gallons

a day.-.'

The

16

MGD

figure

was

derived

from

a

report

of

the

city's

then

consultant

which

was

introduced

before

the

Board

as Exhibit

2

of

the

cso

Exception

hearing

(pcB-gs-214).

Recently,

the

city

leamed

that

even

with past

improvements

the

design

maximum

flow

is

actually

12

MGD

rather

than

15

MGD.

Accordingly,

the

city

requests

a

variance

to

address

this

mistake

while

it

moves

forward

to

design

and

construct

modifications

to

its

sewage

treatment

plant

which

will

arllow

it

to

treat

r6

MGD

maximum

design

flow.

The

city

seeks

such

relief

as

may

be

necessary

to

allow

it

to

construct

modifications

to

the

sewage

treatment

plant

to

increase

rhe

maximum

design

flow

from

12

MGD

to

16

MGD

while

t'emaining

in

compliance

cluring

design

and

construction

with

the

Ex.ception

previously

approved

by

the

Board

to

the

rule governing

the

treatment

of

overtlows

and

bypasses.

The

rule

governing

the

treatment

of

overflows

and

bypasses

is

set

forth

at 35

llt.

Adrn.

Code

g

306.305

which provides:

o

a

I

D

A.

All

co'rbined

sewer

overflows

and

treatment

prant

bypasses

shall

be

given

sufficierrt

treatmenr

to prevent

poil'tion,

oriir.

violation

of

applicable

water quarity

standarcrs

uni.r,

an

exception

has

been

granted

by

the

Board pursuant

to

subpart

D.

Sufficient

trearmenr

shall

consist

of

the

following:

-

a)

All

dry

weather

flows,

and

the

first

flush

of

stonn

flows

as determined

by the

Agency,

shall

meet

the

applicable

effluent

standards;

and

b)

Additional

flols,

as

determined

by the

Agency

but

not

less

than

ten

tirnes

the

average

dry rveather

florv

for

iire

oesign

---

c

o

O

,

year'

sharr

receive

a

minimum

of

primary

treatment

and

disinfection

with

adequate

retention

time;

and

c)

Flows

in

excess

of

those

described

in

subsection

(b)

sharl

be

treated,

in

lvhole

or

in

part,

to

the

extent

necessary

to

prevent

accumulations

of

sludge

deposits,

floa.iing

debris

and

sorids

in

accordanee

with

35

Ilr.

Adm.

code

302.za3,and

to

prevent

depression

ofoxygen

levels;

or

'

,

d)

Compliance

with

a

treatment

program

authorized

by

the

Board

in

an

exception

grantecr

pursuant

to

suupart

o.

)

on

May

9,

1986,

the

Board

granted

the

city

and

Agency's

Joint

petition

for

an

Exception

pursuant

to

35

tll'

Adm'

Code

$

306.305

(d)

from

the

requirements

to

construct

and

operate

certain

cso

transport

and

treatment

facilities.

However,

one

of

the

conditions

of

the

Exception

was

the

adoption

of

the

l6

MGD

maximum

design

flow

which

was

emoneously

included

in

the

Joint

Petition.

The

city

retained

Huff

&

Hufi

Inc.

to

study

the

main

treatment

plant

due

to

problems

attempting

to

treat

t6

MGD.

Huff

&

Huif,

Inc.

recently

discovered

that

the

actual

maximum

design

flow

of

the

main

treatment

plant

is

currently

12

MGD.

(Exhibit

3

at

page

4).

To

address

this

situation,

the

city

is

currently

in

the

process

of

designing

plant

modifications

to

increase

the

maximum

design

flow

from

l2

MGD

to

l6

MGD.

These

modifications

include

an

adctitional

final

clarifier

and

various

piping

modifications.

Attached

as

Exhibit

4 is

a

tentative

compliance

program

schedule

to

carry

out this

work

which

is

currently

estimated

to

cost

$

I

,l

50,000.00.

This

discovery

leaves

the

city

two

alternative

courses

of

action:

(l)

request

that

the

l6

MGD

maximttm

design

flow

figure

adopted

in

the

Exception

be permanently

co*ected

to

the

actual

l2

MGD present

ntaximum

ctesign

flow

capacity

or

(2)

request

a

variance

and

design.ncl

construct

modifications

to

the

main

treatment

plant

to

enable

it

ro

treat

l6

MGD

maximum

design

florv.

The

city

has

electecl

to

expend

the

additional

resources

to

construct

the

---

modifications

necessary

to

treat

i6

MGD

maximum

design

flow,

and

therefore

requests

the

present

variance

to

enabie

the

city

to

remain

in

compliance

with

the

Exception

to

the

cso

regulations

cturing

the

design

and

construction

period.

The

tentative

schedule

attached

as

Exhibit

4

is

contingent

upon

the

city

obtaining

low

interest

loans

from

the

state

of

lllinois

as

well

as

timeiy

-':view by

lllinois

EpA

of

the

necessary

permits'

design

and

construction

plans.

Accordingly,

the

city

requests

that

a varia'ce

be

granted

until

December

31,2000

which

is

one year

after

the

estimated

project

completion

date.

fhe

city

is

a

municipality

located

in

northrvestem

Illinois

on

the

Mississippi

and

Rock

Rivers'

186

miles

west

of

chicago'

The

city

owns

and

operates

its

own

selver

system

and

treatment

plants'

The

city

is

served.

by

two

sewage

treatment

plants,

but

only

the

main

treatment

plant

is

the

subject

of

this

petition

for

Variance.

C.

The

main

treatment

plant

has

an

8

Iv{GD

design

average

flow

capacity

and

l2

McD

design

ntaxinlum

flow

capacity.

It

consists

of

iwo paralrer

grit

removal

chambers,

g

primary

settling

tanks'

a

complete

mix

activated

sludge

process,

two

secondary

clarifiers

and

chlorinating

facilities.

Treated

effluent

is

discharged

into

the

Mississippi

River.

D.

Materials

lrissbarged

(g

l04.l2l(d)

The

Exception

previotrsly

granted

by

the

Board

covered

the

main

treatment

plant

bypass

00lA

which

discharges

corrbined

sewer

overflow.

I

I

B.

Or

-

---

o

The

variance

requested

is

somewhat

unusual

in

that

the

city

already

obtained

an

Exception

to

the

requirements

of

35

lil.

Adm.

code

g

306.305(a)

and

(b)

on

May

9,

I9g6.

The

present

dilemma

stems

from

the

erroneous

description

in

ihe

May

l9g2

combinecl

sewer

overflow

study

by

the

citv's

prior

consultant

that

the

maximurn

clesign

flow

for

the

main

trcatment

plant

was

16

MG^

.'e

16

MGD

figure

wa.s

mentioned

in

paragraph

15

cf

the

Joint

Petition

for

Exception

which

was

thereafter

adopted

by

reference

as

a

condition

to

the

Boarci,s

order

granting

the

Exception'

This

error

has

been

further

perpetuated

by

the

inclusion

of

the

l6

MGD

figure

in

the

city's

NPDES

petmit.

If

the

combi*ed

sewer

overflow

study

had

conrained

the

correct

maximum

design

flow

of

r2

MGD,

that

figure

wourd

have

been

adopted

as

a

condition

to

the

cso

relief

granted

to

the

city

and

this

petition

fbr

variance

would

be

unnecessary'

Nevertheless,

the

city

is

already

moving

forward

to

design

and

construct

modifications

to

its

sewage

treatment

plant

which

will

allow

it

to

treat

l6

MGD

design

maximum

flow.

The

city

is

already

proceeding

to

design

and

construct

modifications

to

its

sewage

treatment

plant

which

wiirailow

it

to

treat

I6

MGD

design

maximum

flow.

These

improvements

inclucle

an

additionat

fi'al

clarifier

and

various

piping

rnodifications.

Exhibit

4

is

a tentative

compliance

program

schedule

to

carry

out

this

rvork

rvhich

is

currentty

estimated

to

cost

$l'150'000'00'

with

the

combination

of

the

new

sludge

dewatering

equipment

insiated

in

eatly

1997

and

the

proposed

nrodifications

to

the

treatment

prant,

the

city

w1r

be

abre

to

treat

design

maximum

flows

of

up

to 16

MGD.

E.

o

o

I

F.

---

l'

G.

The granting

of

the

requested

relief

should

have

no

adverse

impact

upon

the

environment.

If

the

corect

design

flow

of

12

MGD

had

been

includecl

in

the

May

l9g2

combined

sewer

overfl'rw

study

rather

than

the

16

MGD

figure,

the

IZMGD

maximum

design

flow

would

have

been

adopted

as

a

condition

by

the

Board

and

incorporated

into

the

city,s

NDPES

pennit.

Moreover,

based

on

two

stream

impact

sludies,

the

Board

founel

in

its

May

g,

lgg6

order

granting

the

Exception

that

the

cSos

from

bypass

00lA

produce

minimal

impacts

on

the

Mississippi

River'

The

l6

MGD

€no1dss5

not

affect

the

validity

of

the

conclusion

that

the

bypass produces

rninimal

environmental

impacts

since

the

May

lgg2

combined

sewer

overflow

study

was

based

upon

actuai

overflow

monitoring

and

sampling

data,

ancl

the

Huff

& Fruff.

lnc.

study

was

based

upon

analyses

of

sediment

and

stream

samples.

The

city

constructed

all

modifications

to

the

treatment

plant

required

as

conditions

to

the

Exception

consistitlg

of

improvements

to

the

screening

system,

flow

cliversiog

by

increasing

weir

elevations

and

interceptor

chamber

modifications.

Further,

the

city

installed

new

sluclge

dewatering

equipment

in

early

1997.

I.

The

only

compliance

alternative

for

the

city

is

to

seek permanent

corrections

to

the

Exception

and

the

city's

NPDES

pennit

to

reflect

tlle

actual

l2

I\,{GD

present

design

maximum

florv

of the

main

treatment

piant.

H.

o

o

o

I

---

o

t

K,

J.

hterrm tvteasures ($

tO+.

As

discussed

above,

the

Board

has previously

found

that

the

CSOs

frorn

bypass

00lA

produce

minimal

envircnmental

impacts

on

the

Mississippi

River.

Aecordingly,

there

is no

adverse

environmental

impact

to

minimize.

Furthsrmore,

the

city

cannot

treat

flows

over

12

IvIGD

during

the

interim.

The

erroneous

description

in

the

combined

sewer

overflow

study

that

the

maximum

design

flow

of

the

main

treatment

plant

was

16

MGD

was

unfortunately

adopted

by

the

Eoard

as

a

condition

to

the Exception

and

thereafter

made

a condition

of

the

city,s

NPDES

permit.

upon

discovering

tltis

error,

the

city

has

no

way

of

increasing

the

maximurn

design

flow

frcm

l2

MGD

to

l6

MGD

without

undertaking

the

construction

modifications

described

above

in

section

F'

without

the

requested

variance,

the

city

will

bc

in

violation

of

the

Excepti6n

granted

under

35

lil'

Adm'

Code

$

306.305(d)

and

its

NPDES

permit

until

completion

of

the

modifications.

Thus,

the

city

would

be

subject

to

the requircments

cf

35

lll.

Adrn.

code

g

306.305(a)

and

(b)

to

construct

and

operate

certain

CSO

transport

and

treatment

facilities

which

were

estimated

in

1985

to

cost

$54'9

million

in

capital

costs

and

$6.9

mitlion

in

annual

operating

costs.

(Exhibit

2

at

page

7).

L.

Consistency

with

Federal_fu1g

The

Board

nra]

$rart

the

relief

requested

consistent

with

federal

law,

The granting

of

a

variance

would

not violate

any

of

the

provisions

of

the

clean

water

Act,

33

u.s,c,

g$

l25l

to

1387'

Assuming

the

Board grants

this

variance,

the

city

will

seek

a

moclification

of

its

N.DES

o

o

D

---

o

petmrt

to

correctly

impose

a 12

MGD,Jesign

maximurn

flow

until

sueh

time

as

these

improvements

are

completer'

M.

Waiver

of

Hcaring

The

city

hereby

rvaives

its

right

to

a hearirrg

r.

this

maner.

|J.

Affidavit

The

affidavit

of

Mr'

Robert

T.

Hawes,

the

Director

of

public

works

fo^.

::r.:

city,

rs

attached

as

Exhibit

5

in

support

of

the

material

facts

assefied

in

this petition.

_sweLuStqN

The

city

requests

this

variance

to

correct

an

eror

which

was

originaliy

contained

in

a

May

1982

combined

sewer

overflow

study

which

stated

that

the

desig'

nraximunr

flow

of

the

city's

main

treatment

plant

was

l5

MGD.

The

actual

present

design

niaximum

fjow

of

the

city's

main

treatment

plant

was

and

is

l2

MGD.

unfortunately,

this

error

was

adopted

by

referencc

as

a condition

to

the

May

9,

1986

order

by

rhe

Board

granting

an

Exception

to 35

lll.

Adm'

code

$

306'30'5(a)

and

(b)

and

thereafter

included

in the

ciry's

NPDES

permit.

The

Iloard

previously

found

that

cs$s

from

thc

main

trcatnrent

plant

produced

mininral

environnie:iial

impact

on

the

Mississippi

River,

Nevertheless,

the

city

is procreeding

to

implement

improvemcnts

to

its

iewage

treattnerrt

plant

including

an

additional

final

clarifier

and

various

piping

modifications

which

will

enable

tlie

main

trcatment

plant

to

treat

cresign

maximum

florvs

up

to

|

6

MGD'

Accordingly,

the

Board

should

grant

the

requested

variance

based

upon

the

arbitrary

and

rtnreasonable

hardship

which

would

be

inrposed

upon

rhe

city

if

it

were

not

able

to

avaif

itself

of

the

May

9,1986

Exceptiott

duc

to

the

l6

MGD

er'or.

without

the

reticf

granted

in

the

Exception'

the

city

would

he

subject

to

th*."ou,remcnrs

of'35

Iil,

Adr,r.

code

g

306.305(a)

l

I

I

o

---

l"

I

o

o

o

and (b)

to

construct

and

operate

ceriain

CSO

transport

and

treatment

facilities

rvhich

were

estimated

in 1985

to

cost

$54.9

million

in

capital

costs

and

$6.9

millicn

in

annual

operating

costs.

WHEREFORE,

the

City

respectfully

req,,,:sts

that

the

Board grant

the

variance

relief

requested

in

this

petition.

Roy

M, Fiarsch

Thomas

A. Hamilto:,.

(only

admitted

in

Ohio)

GARDNER,

CAR'TON

& DOUGLAS

321

North

Clark

Street

suite

3400

Chicago,

Illinois

6051C

9

o

THE

CIT T

ROCK

ISLAN

---

i

I

I

I

I

I

o

3

---

SEFORE

THE

ILLINOIS

OF

IN

THE

THE

flATER

CITY

oF

OF

RO

IHE

JOINT

PETITIOH

AGEI.ICY

rrrjter:

FOR

i'"ihoffi![rjl'Nf;8,#?,

EXCEPT

Jl'

Jswsn

ouiriri6i

T1jfl|^l?rJl'E

cof,re

r rrED

POLLUTIOX

CONTROL

EOARO

)

)

]

I

rc8

8s-

)

PETiTIOH

FOR

EXCEPIIOH

Agency

by

its

l{01{

("Agency',),

cf

C.ilE

ty

llanager'

the

City

by

J'

its

of

lleil

Rock

Hanager

i{iel

Island

sen

of

Environrenai

and

(,,City,,1,

the

ir

r

Rock

inois

programs,

isiand

Envi

ronrnental

County,

Illinois,

protection

required

l'lississippi

city

facilities'

operate

305'305(a)

pursuant

Illinois

of

Rock

certain

CS'

pollution

to

and

River

facilities,

35

Isrand

The

(b)

It'

combined

Petitioners

anC

to'relieve

Control

have

Ad?n"

do

estimated

minimar

not

serer

code

goard

restrict

submit

the

306'363,

overflorr

impact

grant

city

to

that

cost

streaar

of

an

and

on

(,,cso,,)

because

the

in

exception

the

respectfulry

use,

excess

requirement

water

transport

existing

the

to

quality

constru.ction

35

requests

overfrows

and

to

il.l.

of

Roger

construct

treatr=nt

Adm.

the

that

of

A.

from

Corle

the

Kanerva,

the

and

the

",

;;;:r;;;-

'

unreasonabre'

In

support

of

this

request,

,rri*ontj.::::::trri;.rr,

t'

t'

serer

Rock

(1980)'

l'

Rlvers,

interceptor

The

rhe

lg6

city

totar

miles

system

is

poptrration

located

yest

and

of

treatnent

in

of

Chicago..

Northwestern

Rock

Island

prant.

lhe

Cfty

Iilinois

is

46,g62,

owns

on

and

p€F

the

operates

u.5.

F{ississippi

census

its

own

and

gr'it

requlres

2.

rernovar

it

The

to

Clty

construct

is

seeking

combi,ned

relief

sewer

from

overfrow

Section

transport

30G.305(a)

eapacity,

and

(b)

whichpumping,

'

storage,

primary

setting,

di

sinfection

and

upgradq.

of

existing

I

I

o

o

a

---

o

a

a

o

a

o

o

and

facflftr'es

ten

t{mes

to

dry

treat

rveather

t

an

additional

flow.

The

excess

forlowing

storm

paragraphs

flow

f-.

consistin

or,,

or

first

frush

surmarlze

the

civ's

cso

facilities

rhfch

rf,

be

regufred

rr,n"

petitfon

rvirl

;:ili::J';ff

ffir

those

requr'red

racirities.

The,,]o;:ilon

is

su'arfzed

xisting

c50's

have

only

minimai

fmpact

are

which

,n.

,,tn

detail'

A

descriptfon

iV

the

rill

followfng

construct

paragraphs

if

an

exceptfon

of

thi

s petitfon.

The

CSO

facil

i

ties

of

the

'peration

and

cois

granted

are

described

in

existing

and

proposed

treaEnent'i<-r"::.;,':

uontrol

EquipnBnt

both

for

existing

facilrties

is

a.r."iat

fs

included'

Performance

of

the

city,s

c$

exception

is

presented.

'ed'

Final

ty,

the

iusti

f

r'catf

on

for

grantl

rrg

ir

IA.ILIIIE'

REQUITE'

ey

rHE

nurgs-

d.

lne

City

has

detemine

with

35

i1.

Adn ;^;":::*rned

prelrminary

cos

Exhf

bits

n

.nut*'

code

306'305(a)

and

.(bl.

(Fort

estimates

for

cqnpliance

8,

pp.

73-t66).

compr

ete

t,..r,,.'nt

T;.

i1j 11]--.

The

ci

tv

i

s

r"-,.:,Tff,1,"..JT'r'.T,l;.

"'

for

relief

is

rent

for

the

first

flush

of

stonn

I

dry

reathe,

,lo

t

granted'

fu

additfonal

ten

(rt'lows

provided

this

request

would

also

invor

rouid

receive

primary

sedirnentatl)

times

the

3vs;3'^

ge

design

'-

facilitfes

to

.,,r.

,n.

provf

sion

,rl",ffiJtion

and

disf

nfection.

ir

bvp

a s

se

s

.

..,"',':::

*j

fl

I.'."J-..''.i#

:,

;.

*:

T:'iff

"

"

*

treatnent

Flant,

and

rvould

allo,v

for

gs

would

total

operate

capturein

integration

with

the

main

tieatrieilt

of

fJrst

flush.

Id.

at

l4l.

and

subseguent

secondary

.

,.!

1

to

.

:

r,

.-

,

,r.13

cottpl

iance

proposal

roul

d

upgrade

and

h;,r

r

au,,.

".ol.',

J.

*;;il.;il::Tji:!

:

;,-:.:ffj::.

lfection

for

flows

over

and

)

D

I

---

I

D

I

o

I

a

,

e

o

3

l,*

ll

above

those

either

captured

or

taken

through

the

main

treatfient

plant

nouid

be

provided'

The proposal

invol

ves

an

optirnum

conrbination

of upgrading

the

r,rain

treatnent

plant

for

seconda.ry

trea&Tent

of

the

captured

f]0w

and

primary

treatrnnt

and

dfsinfection

through

sedimentation.

Id.

at.

149,

figure

47.

Ail

flows

greater

than

the

capaci

ty

of

the

main

prant,

storage

and

primary

treatnpnt

facil

itf

es

are

df

scharged

ri

thout

treatmnt.

The

cost

of

the

leas

!

expensive

full

compliance

alternatiye

,,as

estlmated

in

rggz

to be

25.2

mi.rion

dollars'

and

the

annual

operation

and

nnintenance

costs

rere

estimated

to

be

3..7

nlll{on

dellars.

Id.

at.lgl.

Later

figures,

as

set

fsrth

in

Exhibit

A,

would

charge

the

respective

costs

of

the

project

t!

$S4.9

mil.lion

in

capita.l

costs

and

$5.9

miilion

in

operating

costs,

if

treatnent

based

upon

totar

suspended

solids

(Tss)

was

nequired.

The

anounts

rculd

be

slightly.loner

if

treatnent

based

upon

biologfcal

oxygen

demand

(g0D)

was

required.

It

ts

adJusted

assumed

that

for

the

these

current

cost

estimates

value

of

the

would

dollar.

be

revised

uprards

significangy

if

EQUIPI,,IEffI

5'

Rock

Is'land,

'rike

mosi

order

ci

ties

in

the

r{idurest,

origina.tly

constructed

coqrbined

seb'ers

to

convey

both

m.rnrc.ipal

sewage

and

stomi'ater.

Through

the

years'

the

city

has

embarked

upon

a

se*er

separation

progran

r+hich

has

ieft

only

l72

of

the

system

still

combined.

There

are

five

combined

sewer

overf'lows

and

one

treatment

plant

bypass,.which

discharge

poliutants

inio

the

l'lississippf

Rfver.

5'

The

clty

of

Rock

Isrand

is

served

by

tro

se'age

treatrent

p.rants,

but

only

the

main

treatnent

plant

is

the

subJect

of

this

joint

petition.

The

main

p'lant's

service

area

is

derineated

in

Figure

2

of

Exhibit

A.

The

main

treatnent

plant

serves

an

area

of

5,600

acres

o

ll|or

970

acres

oirhich

are

o

---

I

D

?

o

O

C

o

o

served

by

combined

sewers.

These

areas

are

shovn in Lrhibit A, Figure

3.

The

seh€r

systsfl

{s

composed

of

approximately

'170

mir'es

of

seHer.

pipe

sizes

range

frcrn

ffve

inch,

to

ni.ne

feet

by

eight

feet

outfall

at the main

plant.

shallow

serers

lie

at

a

depth

of

three feet,

rhi'le

the

deepest

are

frofll

thiriy-five

to

forty

feet

be1ow

tie

ground.

The

average

depth

of

the

seHers

is

betwien

eight

and

ten

feet.

The

systm

uses

bro

mqjor

interceptor

seyers

the

"north

slope"

and

"south slope.

7'

The

north

slope

interceptor

is

a ninety-six

inch sewer with

a

full

pipe

capacity

of

?04

mgd.

The

souUr slope

interceptor

is a seventy-two

inch

seHer

rith

a full

pfpe

capacity

of'136.8

mgd.

The

nnin

treatment

plant

has

an

8

mgd

design

aYerage

flow

capacity and

a

l6 mgd

des{gn

maxlmum

f'lov

capacity.

It

consists

of

txo

paral'lel

grit

remova'l

chambers,

eight

primary

settling

tanks, the

complete

mix

activated

sludge

process,

trro

secondary

clarifiers,

and chlorination

faciiities.

It

was designed

to

treat

a

goD

loading

of

52,500

Pt- Treated

eff

'luent

i

s

di

scharged i

nto the l'li

ssi

ssi

ppi

Ri ver.

sTP.Etfl

lt'tpacT

AI{,ALYSts

8'

Two

stream

impact

analyses

were

performed.

The

nost

recent

{Exhibit

C),

performed

by

James

E.

Huff, P.E.,

on beha'lf.

of

Rock

Island,

assessed

the

effect

of

CSo

on

bottom

sediments.

Mr. Huff

assessed

stream

impact

through

independent

sampling

of

the

bottcm

sediments

and by

analysis

of

previous

sampling

data

col'lected

by

the

Agency

in.,iJuly,

l9g4

and

by

Missman,

stanery

in

May,

1985.

Ic!.

at

l.

A1]

samples were

subjected

to chemical

and'lysis

as

well

as

physicat

i*'g""tion.

samp'res Here

anaryzed

for

'read,

zinc,

oir

unq

greaset

volati'le

j

solids,

and

total solids. In

addltion,

the

samples

were

ranked

blind

by

three

individua'ls

for odor

intensity.

The

Huff

study

found

that the

discharge

frorn

the

Rock Island

outfall

structure

has.es'ulteO

tn

a

a

o

o

---

D

t

o

o

a

t

c

c

limited

area

along

the

near

shore

of

the

river

with

elevated

pollutant

'leveis'

Id'

at

5.

Thls

area

is

approximately

five

hundred

feet

in length

gy

fifty

feet

ln

rtdth.

The'levels

of

po1'lutants

are

a'l'l

below the

ircan

values

the

I'llinois

Environrnental

Proteccion

Agency

found

in

its

survey of

sediments

rithin

one

mile

of

wastewater

treatrunt

plant

outfalls,

with

the

exception

of

zinc.

Id.

at Appendix.

All

zinc

vaiues

Here

within

one

standard

devfation

of

the I'l'linois

Envlronmentar

protection

Agency's

n*an

yarue.

There

is no

sedlmentatlon

beitr

the

CSO's,

where the

river

bottsn

consists

of solid

rock.:

Thus, there

is

minima'l

impact

in

the receiving

stream

from

the

city's

cs0s.

9. A

study

was

also

performed

by r,ri

ssinan,

stanley

&

Associates,

on

behalf of

the

city

in

1982

to determine

the

frequency,

magnitude

and

irirpact

of

the

combined

sewer

overflows

into

the

Mississippi

River.

Exhibit

g,

ss5-g

arrd

l0'

The

study

involved

I

)

nnnitoring

the

combined

serer

overf'lows

in the

system'

2)

determining

the

quantiU

and

qualiV

of

the

sewer

systenr

overflows,

and

3)

assessing

the

impact

of

the overfiows

on

the

Mississippi

River.

The

study

concluded

that

although

the city

is not

meeting

applicable

effluent

limitations

because

of

the

pollutant

overflow,

the

impact

of

the

overfloH

on

the

I'lississippi

River

is

minima.l.

1o'

The

study

was

conducted

using

|tistorical

records

as

wel'l

as

a

field

investigation

which

consisted

of

monitoring

the

five

cso

discharge

points

and

the treatnent

plant

bypass,

recording

rp.infall

data

and

physicaliy

inspecting

the receivlng

streams.

in

order

to

quantify

the

vo'lumes

and rates

of

flor

discharglng

frcm

the

serer

system,

six

portable

continuously

recording

flow

meters

were

installed

at

1

: esO

locations

to measure

overflows

to

the

l''llssissippi

River.

In

addition,

Rustrak

event

recorders

here

connected

to

ttre

seven

storm

Purps

at

the

Main

Municipal

sewage

Treahrent

plant

to'continuous.ly

o

---

I

I

C

o

a

o

a

a

I

I

record

the

length

of

time

each

punp

operated during

plant

bypassing

caused

gy

storm

events.

To

quantify

the

quality

of f'tow

being

clischarged

irom the

cso

system

durlng

stonn

eyents,

txo

portable,

automatic

samplers

Here

installed

and

maintained

at

tr+o

locations

within

the

system.

overf'low

samples frcrn

five

tyPical

storm

events

at

each location Here coilected

at

preselected

time

interva'ls

to

provide

basic

data on

effluent water

quality.

These

samples

werg

analyzed

for

the

following

constftuents,

'l

)

biological

oxygen

demand

i"go0,'y,

2) chemical

oxygen

demand

(,,COd,.),

3)

suspended

solids,

4)

tota.l

dissolved

sol

ids, 5)

arEiren.la

nitrogen,

6) phosphorus,

and 7)

lead.

The

impact

of the

overflows

frcm

the

five

cSO

discharge

points

and

the

main

treatnent plant

outfal'l were

assessed

through physical

investigatfon.

'll'

The

complexity

of

Rock

Island's

combined

seyer

systsn

required

the

use of

a mathematiea'l

rndej

to

project,

the

overflow

quantities

assoclated

wfth

the various

storm

conditions.

The

simplied

stormwater

management

node'l

sslJl,tH

developed

by

UsEPA

was

used

to

get

a reasonable

picture

of

the

characteristics

of

the

overflorr

that

occur

from

Rock Is'land's

sewer

system.

ssl{ptt

j1as

used

initially

to

describe

.the

basic

rainfall/overflow

re.lationshlps

for.the

study

area

based

on

the

entire period

of rainfall

records

available

(29

years).

The

model

was

calibrated

using

data

obtained

from

the

twenty

storm

and

overflow

events

monitored

during

the field

investigation.

In

l,tarch,

l9gc,

the

city

began

to rpnitor

and

samp'le

the five.oveiflow

locations

on

the

l,lississippi

continuously

for

tuenty-one

(2'l

)

weeks.

The

purpose

of

the

monitoring

anci

sanp'l.{ng

Program'Yas

to

collect

basic

data

on

the

overflow

quantity

and

quality

frcm

the

csO

to

the

r4fssissippi

furing

storm

eyents.

Any

probtems

found

h€re

corrected

inmediately

pursuant

to

a

xeekly

maintenance-

program.

overflcn

quantity

was

analyzed

in

re]ation

to rainfa'll

for

ajt

oi

the

cso

o

a

---

I

I

a

c

o

a

monitored

sites.

Llnear

regressions

of

ralnfal'l

versus

total

overflow

were

developed

for

the

entlre

system.

Linear

regression

was a'lso

used

to

detennine

peak

rates

of

ccrnblned

seyer

overflows.

Based

upon

this

npdel,

it was

detennined

that

8?0

rirlllion

gallons

per

year

of

conrbined

sewer flow

is

befng

rJischarged

to

the

ltllssissigpi

River

from

CSO.

-!g,

at ii and 35-37.

12.

First

f'lush

analysis was

performed by

tabuiating

significant

rainfall

events

vhlch t*ere

fiov

recorded

between

Harch'l6th

and August

8,

.l980.

These

events

were

monitored

at t'ro overflor

locations.

The

first'location indicated-

a need

for ccmplete

first flush

treatnent

of

.|2.2

millioirgallons based on

TSS

and

5.6 mili

ion

gallons

based

on

800;'

the seccnd,

5.3

mi'l'lion

gallons

TSS and

3.9 nilllon

gallons

800" Ihe

detailed

analysis

can

be found in Exhlblt B.

'During

the'103

annual

overflow

storm

eyents,

the

estlmated

total

annual

mass

loadlngs

here

ccmputed

to be

610,000

pounds

of

800

and 4,500,000

pounds

of

suspended

solids

from

a'll

csO's.

0ver.88

of

these

mass loadings

are

discharged

at

the

main

treatmnt

plant

through

p'lant

bypass.

Exhibit

B,

page

67, Because

of

the

size of

the

l'lississippi

River

and its

high flows,

it has

considerable

assimilative

capacity

to

handle a

substantial

amount

of

poliutant

ma'ss

loading.

Based

upon

this

capacity,

csO

plrne

test resuits

and

the

Illinois

Environmenta'l

Protection

Agency's

own

l'lississippi

test

results

[gi,

!{ater

Quality

l'lanagement

Basin

Plan for the

l,lississippi

North

River

Basin

and

the

ilississippi

North

Central

River

Bas.irf1975), it was

concluded

that

tJre

c{ty's csO

inrpact

ls

m{nimal.

The

mean daily flm

of the

llississippi

is

31,085

mgd.

The

ten

year,

seven

day low fiow is

8,900

mgd.

The

cso

overflow

event based

on a

one

year

frequency

stonn event uould

discharge

52.7

mgd

to

the

Rlver

wh{ch

is

insignificant

when

compared to the

ten

year,

seven

day

low

flotr and

the mean

daily

f'lctt of the River noted

above. Furthermore,

because

a

o

a

---

I

e

o

c

o

a

o

o

a{

of

background

concentrations

in the

Hisslssippl, reduction

in

mass loadings

3g

the

CSO

polnts

Hould

generally

not

affect rlver water

quality

upstream

or

doxnstream.

Thus,

"the Rock

Island

CSO's by

thernselves

have

a neg'lfgible

effect

on

the !{lssisslppi

River

water

quality."

see,

Exhibit

A,

page

176.

JsII{T

IGREFJ,IE$I

13. 0n

September

26,

1985,

the

Agehcy

issued

a'letter

(Exhibit

0)

to

the

clty

agreeing

to

support

this

joint

petitisn.

The

clty

in turn

agreed

to

comply

vith

certain

stipulated

conditions

set forth

in

that

ietter.

The

City

has

agreed'to

fully

comply

with

the

listed conditions

as

an alternative

to

naking

the

rpdifications

to its

system described

in

paragraphs

3

and

4

above.

14.

By

complying

with

the

conciitions

of txhibit

0,

the

Ciry

ri'll

be able

to avoid constructing

the

above-described

CSO

treatnnnt

facillties

rhich Hould

have

a maximm

capital

cosi

cf

$54.9

milllon,

and

maximum

operating

costs of.

$5.9

mi]lion

Peryear.

The

modificatiens

whlch

the

Clty

will

nor

make

if

thls

exception is

granted

are

described

in

ri:tail

in Exhibit

E.

15.

These

niodifications

essentially

involve

the

construction

of

head

works imprcvements

to al'lm

operation

of the

treatnent

plant.t

ttt"

design

maximtan

flow

level

.of

sixteen

million

gal'lons

a',day.and

to

construct

improvements

to

the

north

slope interceptor

system

to

assure

that

maximum

availab'le

transport

capaclty

will

be

ut{lized

prior

to

bypassing"

The

city

wil'l also

implernent

a

one

year

shoreline,z/nspection

program

and improve

operat{on

and

malntenance

practices

at the

treatrBnt plant

so that

slrrrtge

and

cebrls are

not

rashed

out frcrn

the

wet rells

into

che

river.

'16.

The

npdifications

vf

ll

cons{st

of I

)

improvements

;c

Ure

screening

system

at

a

projected

cost

of

!75,000,

?)

flw diversion

by

increasing

weir

e]evations

at

a

cost

of

$3,000,and

3)

interceptor

chanber

nrcdlfie'ations

at

a

cost of

$23,000.

The

total

cost

cf

these

moctj,tcations

would

be

$10i,000.

a

o

---

i,i

17'

There

fs

a

minimar

impact

upon the

H{ssrssippi

River

from

Rock

Island's

exlstlng

cfftbfned

sewer

overflws

and

there

should

be

even

less

impact as

a

result

of

the

iointly

proposed

npdlf

ications

to

tie

treatnrent

systcns'

Granting

the

requested

exceptfon

would

provide

a

cost

savfngs

of

over

$55

mi]fton

from

the

cost

of Rock

island's

canplfance

yith

the

express

terms.of

the

rule.

Ihe grant

of

this

petitlon

is

absolutely

bssential

because

Rock Island

does

not

have

the

economic

base

to

afford

such

a

staggering

sum"

IIHEREFoRE'

Petitioners,

Illinois

Environmental

protection

Agency

and

the

city

of Rock

island

respectfully

request

thdt

the

illinois

po'llution

control

Board

ho'ld

public

hearjngs

upon

this

petition,

and

that

the

petition

for

an

exception

to

the

cctnbined

sewer

overflow

treatrnnt

regulailons

be

granted.

Respectful

ly

submi

tted,

CITY

OF

ROCK

]SLA}II)

iLLINOIS-

EHVIRCIJMEHTAT

PROTECTION

AGEHCY

By:

TF:sd/sp/3085e/t

-t

z

t

D

I

I

I

t

o

---

D

I

C

o

o

o

---

-

t

,

o

a

o

o

o

a

o

---

I

t

o

a

a

o

e

a

a

o

---

ILLINOIS

POLLUTION

CONTROT

BOARD

HaY

9,

1985

I

o

a

o

IN

THE

HATTER

OF:

THE

JOINT

PETITION

OF

THE

CITY

OF

ROCK

ISLAND

A}'ID

THE

ILLINOIS

ENVIRONHENTAL

PROTECTION

AGENCY

FOR

EXCEPTION

TO

THE COHBINED

SEI{ER

OVERFLOW

RECULATIONS

)

)

)

)

)

)

)

PCB

85-214

l-

I

I,

UR.

ROY

HARSCH

APPEARED

ON

BEHALF

OF

THE

CITY

OF

ROCK

ISLAND

HR.

THOI,IAS

DAVIS

APPEARED

ON

BEHAI,F

OF

THE

ENVIRONHENTAL

PROTECTION

AGENCY

OPINION

AND

ORDER

OF

THE

BOARD

(bv

R'

C'

Flemal): '

This

rnatter

comes

before

the

Board

uP91-a-joint

Petiuion

for

a

cornbined

s.*ei

"""tif"*-iCSOl

exception'filed

pursuanc to

35

Itl.

Adm.

eode,

Subtitle

C,

cttapi"t-i,

Part

396'-9Y?Part

Dr

by

itr"

C:.ii

oi,Rock

Island

(

"Rock

lsland')

and

Ehe

Illinois

i.tiion-t"nt,a1'

ProEection

Agency

(

"Agency")

'

.Pegitioners

specif

icaffy

requert-"*""pEion'from-35

i11.

Adm.

Code

305'305(a)

aira

305.305

(b

)

.

The

Board

conducted

a

pubLfc

trearing

in

Rock

Island

on

Harch

3, 1986.

In

addit,ion

to

testinony

Presented

by

the

Join!

Petitioners

r

testimony

in

support,

of

the

requested

relief

was

;;;;;;;;6-ui

u..-E"rii

smit'h,'chairPerson

of

the Rock

rsland

Facilit.ies

St.udy

j"rt-of

Expercs.

The

Jury

of

Experts

consisls

of Ehirteen

ciCizens,

representing

a cross-section

of

communigy

interests,

who

fra"e ioffbwed

the

progress

of

all

phases

of

che

CSO

program

for

several

Years'

CSO.

.REGULATIONS

The

CSO

regulations

are

contained

in

35 I11'

Adm' Code'

Subtit,le

Cr

ch;;;;;-i'

Part

306.

Thgv-19re

amended

in R81-I7'

51

PCB

383, Harch

24,

1983.

Section

306.305

provides as follows:

A11

combined

sewer

overflovs

and

treeEment

plant

bvoasses

sha11

be

given sufficient

treaemenE,

eo

prevenE

ooitut;.on,

or

Ehe

violation

of

applicable

water

-.i"naura"

unless

an

excepEion

has

been

granled by Ehe

Board

pursuant

Lo

SubPart

D'

69425

---

t.

t

o

a

-2-

o

suffieient

treatmenE

sha11

consist

of t,he

fo1-10ving:

a)

A11

dry

neaEher

f1ovs,

and the

first

flush

of

storm

flows

Ls

determined

by the

Agency,

shall-

meet

the

aPPlicEble

effluent

sEandards;

and

b)

Additional

flovs'

as

determined

by the

Agency

buE

noE

less

Ehan

ten

t'imes

to

average

dry

veather

flow

Eor

Ehe

design

year, shall

receive

a mininrum

of

primary

treatment

and

disinf

ection

r*ith adequat'e

relenEion

time;

and

c)

Flows

in

excess

of

those

described

in

subsecLion

(b)

shall

be

treated,

in

nhole or in

part!

to Ehe

exlent

necessary

to

prevenE

accumulations

of sludge

deposiEs,

floicing

debris

and

sol"ids in

accordance

vith

35 I11.

Adm. Code

302'243,

and

to

prevent

dePression

of

oxygen

levels;

or

d) Complianee

with a treaEment

Program

authorized

by

Ehe

Board

in

an excePEion

granted

pursuant to

Subparc

D.

!

subpari.

D al-lons

the

dischsrger

to- file

a

Petition

for.

an

exceptioir

eieher

singly,

or

jointly

vith Ehe

Agency' as

Rock

Island

has done.

A

joinr

petition

nay

seek

an eMpligl

based

on

rninimal

discharge

impact

ai

pro*ided

in

Section

306.351(a):

An

exception

justification based

upon rninimal discharge

irnpacE

snatt

includer

as

a minimum,

En

evaluation of

receiving

stream

ratios,

krrovn stream

uses

t

accessibility

to

sLream

and

side

Land

use

activiEies

(residenEial,

commercial,

agriculEuraf

industrial'

recreational),

frequency

and

extdnt

of overflov events'

inspecbions

of

unnatural

bottom

deposits, odors,'

unnatrrral

floating

meteriaL

or

color' stream

morphoLogy

and

results

of limiEed

sgream

chemical

analyses.

Rock

fsland

and

the

Agency

believe they

have made

the "minimal

impact" showing

pursulne

Eo

SecEion

305.35L(a).

SUPPOR,T.

DOCUT,{ENTS

Rock Island

has

undertaken

several

studies

of

ics CSC

siguagion,

Ehe

report,s

of

which have

been submitted

as

exhibigs

in

support

of

the

Pet,iEion.

The

princiPal,among

these

is

the

Rock

.i.i

f.a"a',.

,

I.1l-.inoi:s

.

.Gqrnblneg'

Sever'

'Ove'r

f'lo+t"Seudy

,

preparad by

H

s,rbmitted

as

Exhibit

2

(referenced

as

Exhibit

B

in

Joint

Petition).

Ttris

document

is

augmented

by

t'ro

other Hissnan'

Stanley

&

Associates

studies,

a response

supplement

t,o

the IEPA

review

legter dated

August,

1983

(Ex.

1; reEerenced

as

ExhibiE A

in Joint,

Petition),

69-426

---

I

o

anci

Froposed.,Pla.n..f

or.'POTlrl

.a.nd'

.T.rans'po1l!-lf,gpggve{aent's

"f

or"Join't

iiio

ic

gffic-="cicion).-ThesesE'udiesconsiderramongot'her

maLters,

descripEion

of

the

Rock

Island-se\rage

transPort

and

treatr:rent

sysEem,

characterizat,ion

of

alternate

control

mechanisns

r-

determinaEion

of

the

quenEiEy

and

qualiEy-of.CSOs

'anC

assessmenb

of

the

impact of

the

overf

lovs

on

Ehe

l'{ississiPPi

River.

.

A

fourth

major

document

submitt.ed

as

Exhibit

3

(referencac

as

Exhibit C

in

3oi-ne

PeLition)

vas

prepared

by James

E' Huff'

p.E.,

and deals

r{ith

CSO effects

on

itrLam

boEgom

sediments.

The

record

before

the

Bcard also

contairrs

several

exhibiEs

subrnlEted

in

support,

of

particular

aspects

of

the

EesEimony

presented

at

hearing.

BACKCROUNq

The city

of Rock

Tsland,

nhich

has

a

population of

46,862

(f980

censrrs),

is

located

in

nort,hvesEern

Illinois

on

tl.e

Hississippi

and

F.ock

Rivers.

Rock

Island

owns

and_oPerates

ics

own sysElrn

of

seners

and

rrasge

treat,ment,

plants.

The system

incluies

approximately

170

miles

of

sewers.

It

also includes

tvo'

t,reatment

iiangs,

Ehe

Hain

PLain

and

the

Southvest

Plant.

Only

the

}tain

Piant

anci its

Eributary

sever

sysEem

are the

subject

of

the

joint

petiEion.

The

Hain

Pl.ant

is

served

by

t.no

18j9r

inteiceptoi

serers,

the

North

Slope

InEercePtor

and the

South

Slope IntercePEor.'

As

vit,h many

oLder

cities

in

the ilidnesE,

Rock

rsland

originall-y

constructed

combined

sewers

Co

convey

both nunicipal

""rig"

uni sLorm?ater.

Betveen

1970

and

L979

Rock Island

undeit,ook a S6.9

million

Program

to

seParaLe

combined

severs

serving

about

2,830 acres

of

the

5,600 dcres

tributary

to,

the

Hain

Piant

(R.

ar

10).

At

present

approxiroately-

177

of

Ehe

area

tribuEary

to

the

Hain

Plant-

(970

of

5,60O

acres)

remains

combined.

The

combined

areas

are

locat'ed

in

the nort'h-central

section

r:f

the

city

(Ex"

10),

and

correspond,

wit'h-

the

principal

commercial

areas

of

che

communiEy

(Ex.

2, Table

1)

vhere

separat,ion

vould

be nrost

difficule

and

expensive

(R.

at

11).

I?re

requested

exception

c;ncerns

six

outfail

structures:

outfaLl

0O1A

is

a bypass

located

at

Ehe

Hain

Treatmetr!

PlanL;

out.fa1ls

OO2-005

are- overfloss

from

the

North Slope

InEercepcor.

Outfall

001A discharges

directly

to the

Mississippi

River.

'ougfalLs

002-005 discharge

in

the loner reaches of

Syl-van

'Slough,

a

high-velociEy

side

channel

of the

Hiss.issippi River

vhicF has be6n

deveLoped

as

a

race-rray

for

a hydroelectric

pl-ant

located

upstream

from-the

CSO

discharges

(R.

at 59).

69427

---

{

I

o

o

{'

-4-

The

Hain

TreaLment

Plant consisEs

of

tvo

para11e1

grit'

removal

chambers,

eighE

primary seEt,ling

tanks,

the

complete

nix

acE,ivated

sludgc

pro-ess,

tvo

secondary

clarifiers,

and

chLorination

ficiiit,ies.

The

plane

has an

8

million

gallons

per

day

("rngd')

design

average

flov

capacity

and

-a

i6

ngd

maximtrm

flow

cafiaci.ty.

fhe

NortF

Slope

InEerceptor

is

a ninety-six

inch

sewer

rith

a ful1

pipe

capacity

of

204

rngd.

As eon<liEions

associat,ed

nith

granting

of the

requested

except,ion,

Rock

Island agrees to

underEake

certain

modificaLions

to its systern.

These

involve the

consLruction

of head

vorks

improvernlnEs

to

al1ow

operation of

the

treaLnenL

Plant

at the

deiign

naximum

level

of

16

mg-

and

improvements

to'-ne

i'iort'h

Slop6 intercepEor

to

assure Lhat

nieximum

available

transport

caplcity

vi1l be

utilized.pr'-or

to overf

lc',l

events'

The

modificltions

consisE

of

(1)

rnpFov€$€nts

Eo

the screening

system

at

an

est,

jirnated

installation

coit

of 575,OOC,

(2.)

intercePEor

chamber

modificsCions

at an est-irnated

cosL

of. S23,000,

and

(3)

increase

in

eleveL-j-ons

of diversion

veirs at

an

estimaEed

cosE

of

S3,0OO.

The

agreed

to

imprcvements

thus

aggregaLe-eo

I

total

estimaied

cost

of 9101r000.

lhe

inprovements

rire

further

deEailed in

Exhibit

5.

DOqUHENT.Afr

ION.

OF'' HINIHAL

.

I.HP.ACT

The Hississippi

River in

the

reach

of

t,he cso

and.Ehe

bypass

outfalls

has

recreitional

use for

boating

and fishing

(R.

at

22)

t

sma1l

boating

use

is charact,erizecj

as

nheavy'

(R.

8t

28). Some

vater

skiing-rioes

occur,

but,

ttre

amoulit

of

swirnming

vhich occurs

is

no| addressed

in

the record

(R.

ae

291.

The riverr but

not

Sylvan

Slough,

is

also used for

commercial-

baige traffic.

The

l.eeresE

dovnsLream

kn.wn

vithdraval

of

vater

for

pubLic water

supply

i-s at, HuscaEine,

rotra, approximately

25

miles

downstream.

Access to

the

river in t,he

vicinity of

the

CSOs

and bypass

is

linited.

Through

most of

the

reach in

quesEion

Ehe

community

is separated

from

the

river

by a levee

vhich does noE have any

point- of

pub).ic

nccess

(R.

at

21.1. Land

beEveen the

levee

and

the

river-is

variously

barren

sand fiets'

rock flats, and/ot

vocds

vhich

range

in

nidth uP to

150

yar,is'

depending

in

Part

on

river

stage

(R.

aE

21-8). Additionally.

mu:ch

cf the

landward

side

of the levee

is

occupied

by industrie!

land of limited

access.

From Harch

to

AugusE

of

1980' an

overflor* monitoring

and

sampLing

program

'rras

conducEed

Bo

collect

basic dsta

on

the

'

quaircity

ind-qualit,y

of the CSO

overfLovs.

Tttis

Program

Consisted of

measuring

flon

at the

six

discharge

points

with

cont,inuous

f lov

lnebers,

moniEoring

of

the S.ength

of time

the Hain

PlerE

Fumps

clirecEed

discharge

to

outfEll

001A,,sampling

of

uater

quality,

Lnd

physical

i.nspeetion

of the five

CSO

ciischsrge

points.

I

1

69428

---

I

f

I

c

o

o

Daca

frorn

the

1980 monitoring.and-sampling

progr?t

Yuo--.

ucirizea,

along

*irt historical

rainfal-1

data,

to

estimaEe

fne

number

and

volumes

oE

overflow'evencs

that

could

be

expected

in

anaverageyear;tr."estirnaEionwasdoneuti].izingthecompuEer

Drosraln,

Simpliiied

Storm

Water

Management'.Hode1

(SSWHH)'

This

:;?;;;:

lnJ^i""g""

rhe

folLowing

num6er

and

volumes

of

events

;;;;'llli''-Jt."t"'g"

point

p"'

v5"'

(Ex'

11):

-5-

NUHBER

OF..EVENTS

-TOr-

15

24

50

40

50

VOLI.IHE

{.ms,/vea'r)

--TETT

L2.5

7.6

10. 3

79

.3

9.6

OU.TFALL

--r5-dTr

oo2

oo3

004

005

005

o

o

t

o

These

daLa

indicate

thaL

bypass

oolA

can

be

expecEed

Eo

di-scharge

;;;;;.;;;ruii-7oo

million

girro's

from

103

evenrs

during

the

average

year .

ait;i;;iyr

-int.

ri"e

ot'her

csos

can

be

expectsed

to

discharge

"ppro*lri;;it'

izo-r;.rii-on

gallons.during

approxinateLy

5O

evenEs

p"t

y"ur-inl'ut

36-7).

T1't;

12O

srillion

-gaL3'on

figure

nould

be

reducea-Uy'-COZ-and

t'he

number

of

events

d6creased

to

4O

o"i-v"ut

if

the

irnprovements

as

agreed

to

by

PeEiEioners

are

impllrnented

(R.

aE

43).

NotallofEheTOOmilliongallonsdisehargedat09lA*:

derived

from

Ehe

combined

sewer

lyst,em.

Due

Eo

t'he

particular

configuration

oi

tne

Uain

Plant

(ix.

19),

some

separaged

storm

seyer

discharge;

;;;

direcred

irti."in-o"ifl1l

ooli

(Ex.

19)'

It

is

esEimaced

that

auout

I/3 gi

the

7oo

million

gaLlons

derives

;;";-t*futuEed

storn

severs

(R'

ei

73)'

.sinrilarly,someofthelO3annual'eventsestimatedfor

outfall

oolA

are

afparent,ry

Eriggered-

by

infilt,ration

into

the

separat,ed

sEorrn

sewer

system

tuEf,.r

than

by storm

surchargirig_9f

;!-;;;;";;-;;,;;";;"se;-iR'

at

ss,

61-71):

th'

Py'P.s

6t^

0o1A

are

afixea

to

vei

tni1"

which

receive

flov

from

both

the

slorm

and

saniE"ty

""t"t

system

(Ex'

19)'

The

filLilg

of-t'hese

wet

wells

causes

ttt"-p"rir"

to

activate

and

drain

the

ve11s

via the

outfal1.

The

i""lta'is

unclear

as

to

nhat-

Percengage

of the

lO3

evenEs

are

retaied

to

simple

emPEying

of

tshe

vet' wells'

Ag

one

poinr

it

is

""irit"a-thaE'inf

iltrit'i-on

is

resPonsible^for

cau'sing

[;;";"ii"-i"-iiii

and

discharge

aPProximat'elv

20

to

30 times

per

;;;r"i[:-";-49:501.

Later

in-the-

iecord

it

is

indicated

that

tt"r"

coulC

constitute

"t,he

majority"

of

t,he

pumping

events-aE

Oiiii-tn.-"t

5lt;-;;;

itt"t

rtt"v-constit''te

appioximaielv

half

of

the

103

events

(R.

at

75).

PeCitioners

have

presented-

testimony

iii"r-J"ting

rses

Ehere

were

only

seven

occu.rrences

of

bypalses

at

00IA

vhicfr

yere

oi"utione<l

by

fiow

to

the

Hain

Plant

exceeding

;;;"pi;;;;"

16

mgd

tJesign

maximum

f1ow

(R'

at

105)

'

o

69429

---

t

I

o

t

In

comparing

the

volumes

of

the CSOs

to

Ehe flov

in che

receiving

strean'

Pet.it,ioners

noEe

thaE the mean

daily discharge

of the Hississippi

River aE Rock Island

is

31'085 mgd'

and

that

the ten-year

seven-day

lov

flov is

8'900

mgd

(PetiEionr

par.

12).

fn

eontrast,

an overflov cvent

of a one-year

frequency

nould

discharge

about

52.7

million

gallons

(Peticionr

par. LZ).

Thus,

if

the

one-year

recurrence interval

discharge

were

to

occur

aE

the

time

of

average

flon in the

Hississippi.

it

vould

be

subjecr to

a receiving

rat,io of

590:1; if iE occurred aE the time

of the

ten-year seven-day

l-ow flon

iE

vouLd be

subject

to

a

mixing raEio

of

169:L.

Chenrical

analyses

of Ehe

CSO

discharges

as

conducted

in

1980

included

the folloving

parameLers: biochemical oxygen

dernand

(BOD),

chemical oxygen denand

(COD),

total

suspended solids

(TSS),

total

dissolved

solids

(TDS),

ammoniE nitrogen,

phosphorous,

and 1ead.

Yolume

analysis

inCicaEed t,hat the six

CSOs in combination make

an average

annual contribution of

0.5

million

pounds

of

BOD

and

4.5

million

pounds df TSS

to

the

Hississippi

River. Over

8OZ

of t,hese

conEribut,ions

are

discharged frorn

at the

Hain

Plant via

O01A

due to the

larger

volune, number of events, and pollutanE loadings

at that

point

(R.

ae

37).

rGiven

the high flovs of

the

Hississippi

Ri'rert

.

Petit,ioners

eonclude that "the Rock

Island CSOs

by

themselves

have a

negligible

effect,

on

the

Mississippi

River

vat,er

quality"

(Petition,

par. L2;

Ex.

2,

p.

176)"

In a rnore recent study

(guie

Studyr

Ex. 3),

assessment

was

made

of the

impact, of

Hain

Plant out,fall

0o1A'

on

bottom

sediment,s..

.

Tl're

assessment. vas

nnderEaken

through

independenE

sampling of Ehe

bot.tom

sedimenEs

and by analysis

of

previous

sampling

dat,a

collected by

the

Agency

in

Juiy

1984,

and by

Hissman,

Stantey & Associates

in

Hay,

1985. All

sanples

vere

subjecied

to

chemical analysis as

well

as'physically

inspected.

Samples

were

analyzed

for leadr

zinc,

oi1

and grease,

volatile

solids,

and t,oEaL

solids

.

In

addiEion, the samples were

ranked

blind by

three

individuals

for odor intensity.

The Huff Study

found

that discharges

from Ehe bypass

CSO

has

resulted

in

a

limiEed

area along the near

shore of

the

river

viEh

elevaLed

pollutant

levels.

This area

is

approxirnately

five

hundred

feet

in

length

by fifty

feet in

width.

To provide

perspect,ive

to

the

Ievels of

pollutants

as

found,

Huff

compared

the cbserved 1evels

to

those

reeorded

in

a

general

Agency

study

of bottorn sedirnent,s collected from sites

donnstream

of

sewaqe

treatmen!

plant,s

(Ex.

16). fn

the

case

of CSO

OOIA

all

meai

vaLues

of

observed

consEit,utenLs are

belov

the

mean values

found

ffiion

below

the

five

North

Slope

fnterceptor

CS0s,

vhere

the

river

bottom consists

of

solid

rock.

a

o

o

o

o

c

o

69-ii30

---

I

c

o

by

the

Agency

in

the

general-

s:rvey

of

sediment

collected

viLhin

one

mile

of

vastewagei

treaen'en't'';i";;

o"tFarrs'

on

Lhis

basis

'

Huff

concludes

itui

cr."

"irpacr-fI"*'-irt"

existing

Rock

rsland

combined

sewer

i"Iiri"t"

on'ttte

Hississippi

River

is

nou

discernible

based-uPon

these

t"aLi""E-reii'tts

in

the

zone

oE

iip""e'

(R.

aE

84)'

TofurtherassureEhatEheCsoshave.minirnalenvironment.al

irnpacri

Rock

r.r!ia-i',"s-u!i""a;

;;-;'

conaicion

Eo

granting

'

of

the

excepEionr

Eo

lmplement'

"

oo"-y"ur

shoreline-inspection

prosram.

ftris

iiiii";-r;

l;;"'";;;

;;-a;;;tify

aird

document'

the

amounc

of

debri!'Ii'.liu"i"ui"

to-itr"

CSot

(R.-at'.

16)

'

EEONOMI'C.

.TIARDSHIP

Rock

rsland

has

determined

preliminary

cosE

estimates

for

f

utl

cornprian""*ri;;

3;;;i;"

s6ei305?ui

un'o

306.30s(b)

'

under

t,hese

rules

noit<-'-;i";;-nould

uJ-t"q"lt"-g

t?

provide compleEe

rreaEmenr

so,

iir"-il;;t

ii"atr

"i

"iJtrn

f10vs.'

An

additional

ten

times

the

average

design

dry

*eattter

flow

vould

require

primary

sedimenrarion

lii

ll"lfii""rion.--ihe

Petitioners

be]'ieve

that

Ehese

requiremlnis-tot'fa

''""t""it"it

'

as

the

leasE

expensive

option,

the,pto"ition-of

U"fot-lio''na'

:91:1:d'

off-line

storage

faciliEie"

..

I"ii"il

iia-i"au"E

the

occurrence

of

overflows

or

plant

bypas"e:'

These

seorage

iacilicies

vould

operaEe

in

inEegratron

ttih

ihe

main

ct"ut't"nc

pLant'

and

voitld

a11on

for

total

caPture

"na

suUsequenE

t"ionaui'y

greaEmenL

of

the

firsc

flush.

Addit,ionalLv,

ful1

t";;i;;;;e'woutd

r9eui13-:qg:i:r:g

Lhe

Hain

p1ant,

to

uiroyr'at.tainmeni'of

current

design

standards

tor

EreaErnent

plant

componentu

"nI

fryaraufic

capacfty

(PeCition

Par'

4).

In

aggregaEe

the

full

complianc:

u1!::l"t'ive

was

estimated

in

1982

.o

"oJl-i2;';;

;iiiion,

and

the

annual

0peration

and

mainrenan""

"oltr-vrere

esEi*ui.i"Io-t.

SS'7.rniliion

(Ex'

2'

P'

181).

Later

figuresr

as

se-t-itttn

in

Exhibits

1 and

i2'

raise

rhese

f igures'i3-r-o;t;i

;i-S34:i'-riirion

in

capital

costs

and

S5.9

million

in

oPerat'ing

toti"

""4"t

the

assumlclon

thac

total

suspended

.orii"-I;i[ioi"o"1d

also

be

reguired.

The

latt'er

;;'";;;-;';i;-;;

;'i;'et'irv

lover

ir

treatmenE

based

upon

biologicaL

(sili

giiiF"

dlmand

(BOD)

vas

required"

(Petit'ion'

Dsr.

4).

At

hearing

tll'

.nouelt'i'-itttt"'-Citt

Engineer

of

Rock

island,

furthei-i""Eie;."a^t.nal-tne

cost

of

fu1l

c.ompliance

is

esrimated

ao

i"

iiil':o,oo0,

-and

if

these-costs

Yere

sPread

over

a

20

year

p"tioa

at

an

interest

raEe

of

87

'

t'he

average

residentialseverusechargerrouldincreasefroms3chargevould

increase

gro*=lii'ii-t"

sr6s'90

per

quart'er'

'

c

69431

---

I

o

o

-8-

ORDER

t

Dr.s

cu

3sr€N

.

OF' OR:DER

The

Board

deLermines

that

Petitioners

have-s-h9tr9

pursuant

to

SS

fril-lam.

Code

5Oe.jSff"l

that,

excePlio!

to

35 I11.

Adm'

Code

:OOl:OStul,

as iE

relates

to

firsg

fluih

of

sEorm

flovs'

and

to

3;-iii:

eai'.

c"i"

loo.ioituj

r+oura

produce

minimal

impact

on

Ehe

receiving

sEream.

Accordingly,

the-Board

vi1l

grant.ghe

"i""pui"i.

Ttre

Board furthEr-ni1l

accept

the

conditions

as

agreld

t,o

bY

Petitioners.

Lf,ffir,fr-i"r,r.

i;

A57;,

the-Ea-rd

vi11 int,roduce

into

the

orderr

as

proposed

by

PetiEioners,

language

identifying

the

scope

of

the

excePtion

as

granted.

The

Board

noEes

that

the

Agency

has

emphasized

lhat'

its

,,rppoii

of Ehis

pet.igion

is

pr"ti"al"d

on

the

assumpt,ion

that

the

relj.ef

is

resEriliea

only

to

those

substantive

_requirements 9ot

effluent

EreaEmen!

of

CSbs,

and

noe

to

relief

from

vrater

quality

.i""a"iJ.-tn.

aL

94).

Rock

fsland

appears

tlhave

been

avare

of

this

condieion,-6nd

has noE

object'ed

tb

i't'

Ttre

Board

itself

noEes

that

up

to

the

presenE

time,

the

United

Stat'es

En"iio"r"neai

Prot,ection

Agency

has

indicated-that

only

variance

(i.e.

non-permanenE)

relieE

from

va_ter

qualit'y

standards

can

be

giunt"d-"ohrisEent

vith

the

Clean

t'JaEer

Act

(see

document

entigled

"staeus

Report

on Discussions

nith usEPA",

daEed

october

4;-i,85;

this

document

is

part of

Ehe

record

of,

and

is

cited

in'

(

e; tJ

""'

.Clt"

* i

.

"

l'

@rrp9:q1lfrl!1i!

ei

9@ir9

nn

eI

te

k l'E ?e

e€

Ei

on

gnc'y

I

rvD

oL'oL

ffi-December

5,

I9E5). To

assure

1. The

CiEy

of

Rock

Island

is

hereby

granted an-excepEion

from

the

Ereaeme;E

requiremengs

of

35 I11.

Aam'

Code

305'305(a)'

as-",rcfr

provision

relites

to

first

flush

of

storm

flows,

and

from

35 I11.

iar.

code

306.3O5(b),

subjecE

to\the

foll-owing

conditions:

a.

such

excepEion

sha11

be

limited

to

combined sewer

outfalls'OO2,OO3,004,OO5,and005andtobyPass

OO1A, as

identified

in

this

proceeding

'

b.

The

City

of

Rock

Island

shal1

implernent'

all.

modificacions

to

iE,s

sewer

sysuem

as

identified

in

paragraphs

14,

15, and

16

of

the

PeEit'ion

in

Ehis

Proceeding.

c.

The

City

of

Rock

fsland

sha11

implement

t'he

,

shoreline

inspection

Program

described in

paragrpah

15 of

Ehe

petition

in

Ehis

proceeding'

2.

this

grant of

excePt,ion

does not

preclude.lhe

Agency

from

exercisin[

its

authority

Eo

require

ai

a

permit

condition

a)

a CSO

monitoriig

Program

sufficient

Eo

assess

compliance vittr

.

69432

---

I

,

I

t

o

o

C

-9-

{

this

excepEion

and

any

other

Board

r-egulations,

including

secEion

306.305(c);

and

b)

otirer

controls

if

needed

for

compliance?

i;;i;;i;;'eompliance

viEh

valer

qualitv

standards

'

3.

This

granE

of

except'ion

is

not

to

be

construed

as

affecting

rne

eniorceability

9i""ty

trovisions

of

this

excepEion'

oitr.t

Bolrd

regulations r

or

the

Act'

'

4:l{it,hinforty-fivedaysofEhedateofthisOrder''tshe

City

shaLl

exeeuie

a- Certifi"Li:.on

of

Accept,ance

and

Agreement

to

be

bound

to

all-i"r,n,

and

conditions

of

the

exception

grsnted'

Ttre

Certification-sha1r

ue

s',umlllta

t'o

!!9-Agtllv

lt

2zoo-.

Churchill

Road,

Springfield,

riii;;it

'-

azloO'-

rha

fort'y-five

dav

period

sha1r.

be

held

in

abeyance-auring

any

period

that'

this

rnat,ter

is

being

"pp""i"a.

fn"-gorm-of-saii

Certificagion

sha1l

be

as

follovs:

CERTIFICATION

.

'

I,

(We),

'i""..

havine

read

the

order

of

rhe

l

d'

il

lcP

85-2L4'

;;;;a

u;y-t;

i6e6l-""aeiseana

and

accepr-lhe

said

order'

realizingthaEsuchacc_ePEance-renders.alltermsandcondiEions

Ehereto

Einaing

and

enforceable

'

.'...'.'.'.''.....'.......'.'

PeEit,ionet

.

ffi

IT

IS

SO

ORDERED.

Board

Hembers

Joan

Anderson

and

Jacob

D.

D'rrne11e

concurred.

Illinois

Pollution

Control

Opinion

and;$rder

vas

1986,

adopted

on

the

day

of

by

a

vot,e aE

':"4

I,

DorothY

H.

Gunn'

Board,

herebY

certify

Lha

a

I

.

Gtrnn

I

L;IerK

Pollution

Control

o

69.{33

---

a

O

o

o

a

---

---

f

a

a

o

a

o

o

o

PRELIMINARY

ENGINEERTNG

REPORT

for

THE

UPGRADE

OF

THE

ROCK

ISLA}.ID

WASTEWATER

TREATMENT

PLA}.IT

December

1997

by

James

E.

Huff,

P.E.

\/

/I\/

7\

HUFF

&

NUFF,

INC,

ENVINONMENTAL

CONSUUTANTS

LTGBANGE.It

LINOIS

o

---

)'

TABLE

OF

CONTENTS

1. I}ITRODUCNON

.:::;

2,EXISTTNGCAPACTTYANALYSIS

........3

2.1

GritChambcr

. . ..

'.

.3

2.2Pdirary$edimenation...'

........3

].3

AerationTanks

'.....4

2.4

Secandr'ryClarifien

........4

2.5

SludgeDigestionCapacity

.........4

3.

PROPOSEDI,|PGTIADING

..

.......6

3.1 AdditionalseeondaryClarifier

"....6

3.2

Pnmuy

$edhoenationModifications

...

.........

?

3.3

$ludgeDigcstion

.,...7

4, PRDLIMINARYCOSTESTIIV{ATE

........9

LISTOFFIGIJRES

FIGURE

I;

ROCK ISLAND

EXISTINO

WASTEWATER TREATMTNT PLANT

SCHEMATIC ,,,

,.,,,,,2

LISTOFT',B',ES

TABLE

t:

g,,ASTElltATE.R,

T?"EATI'{ENT

UPCP.ADE COST

ESTIM,ATE

, .

. . .

9

LTST OF APPENDICES

APPENDIX

A:

SI.TPPORTINC

CALCTJLATIONS

APPENDTX

B:

PROPOSED

SITE LAYOUTDRA\YING

---

l'

I

o

c

o

a

o

)

o

o

I.

INTRODUCTTON

'I]rleCiry

of Rock

Islaml's

Wastewater Treaftent

Plant

r+'as

lasl

upgraded in

the early 1970's. Tbe

treatnent

plant

was desigred

io

prccess

8.0

MGD on

average,

wi& a

peak

flow

of

| 6.0 lv{GD. The

tr€atn1ent

process includes

grit

removal,

plJrmary

sedimentation"

aclivated sludge, and

seasonal

disinfection.

Secondary,.sludge is cuncntly

wasted to the

pririrary

sedimentation

basins.

$ludge

is

processcd fuough

nro

anacrobic sludge

digesters,

then

dewatered

on

sand drying beds

or a nerv

belt

fii.ter

press,

Ercess

flows, not

proc.cssed

through tha