ILLIi.~OiSPOLLUTIOi~CONTROL BOAicD

April

1,

1987

IN THE MATTER OF:

)

THE

SINGLE PETITION OF

)

THE CITY OF LASALLE FOR

)

PCB 8b—2

EXCEPTION FROM THE COMBINED

)

SLWER OVERFLO~REGULATIONS

JOHN

S. DUNCAN,ESQ. APPEARED ON BEHALF OF THE CITY OF LASALLE;

THOMAS DAVIS,

ESQ. AP~EEAREDO~BEtIALF OF Tt~EILLINOiS

ENVIRONMENTAL PROTECTION AGENCY.

OPIi~IOi~Ai~DOR~R OF

Thi~

BOARD

(by 3. Theodore Meyer):

This matter comes before

the Board on the January

2,

l98b

petition of

the City of LaSalle

(LaSalle) for exception to

the

combined sewer overflow regulations

(35 Ill.

Adm. Code 306.305(a)

and

(b)).

hearing was

rield on July

21,

1966

in LaSalle.

Additional information was provided on August

21,

1986 and on

February 18,

1987.

Tne City seeks relief from Section 306.305(a)

which would require construction of

a retention pond with

bleedback pumping and provide secondary treatment for

a first

flow from volume of

8.7 MG

at

a rate of 140 MGD.

The City also

seeks relief from 306.305(b) whicn would require construction

of

relief sewers,

primary treatment and disinfection for excess

flows

up

to 20.8 MGD.

CSO REGULATIOi4S

The CSO regulations are contained

in

35

Ill. Adm. Code

306.302, et seq.

Section 306.305 provides as follows:

All combined sewer overflows and treatment plant bypasses

shall

be given sufficient treatment to prevent pollution,

or

the violations

of applicabie water

standards unless an

exception has been granted by the Board pursuant to Subpart

D.

Sufficient treatment shall

consist

of tne following:

a)

All dry weather flows,

and the first flush of storm

flows

as determined by the Agency,

shall meet the

applicable effluent standards;

and

b)

Additional

flows,

as determined

ty

the Agency but not

less tnan ten times

to

sicl

average dry weather flow

for design year,

shall receive

a minimum at primary

77-21

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—2—

treatment and disinfection with adequate retention time;

and

C)

Flows

in excess of those described

in subsection

(b)

shall

be treated,

in whole

or

in part,

to the extent

necessary to prevent accumulations

of sludge deposits,

floating debris and solids

in accordance with 35 Ill.

Adm.

Code 302.203, and

to prevent depression of oxygen

levels;

or

d)

Compliance with

a treatment program authorized

by the

Board

in an

exception granted pursuant to Subpart

ID.

Subpart D allows the discharger

to

file

a petition

for

an

exception either singly,

or

jointly with the Agency.

The Agency

testified that LaSalle did take all the necessary steps

to

qualify as joint petitioners with

the Agency,

including

submitting

a Phase

I study on October

5,

1983 and

a Phase

II

Study on October

23,

1984.

However, the Agency chose not

to co-

petition with LaSalle because

of the late date

at which LaSalle’s

petition was received,

and because of Agency concerns related

to

whether water quality and other environmental impacts will

be

alleviated after

the City’s proposed improvements are

completed.

P.

at

7.

In order

for

a discharger

to receive

a CSO exception,

a

certain level of justification for

the exception

is required

to

be submitted.

This level

of justification differs depending

on

whether the discharger

files

a single or joint petition

for CSO

exception.

Th~level

of justification required

of

a joint

petition

is set forth

in Section 306.362 which provides

for

a

demonstration under

Section 306.361(a)

(i.e., minimal discharge

impact) which

is not available

to single petitioners.

Iowever,

LaSalle as

a single petitioner,

justifies its claim

for

a CSO

exception based

on Section 306.361(a).

Section

306.361(d), applicable

to single petitioners

under

Section 306.362, provides that

a discharger may establish that

because

special circumstances exist,

a detailed water

quality

evaluation would be inapplicable for reasons of irrelevancy or

the expense of data collection

in relation

to the relevancy of

the data.

In this regard,

Mr. Tim Zook of the Agency testified

that although

a detailed CSO impact study

(i.e.,

Phase

III Study)

was not conducted,

a study prepared for LaSalle by Serco

Laboratories does give substantial

information concerning water

quality impacts.

Based

on this testimony,

and

on the fact that some of

LaSalle’s discharges are due

to dry weather discharging which

must

be eliminated before

a realistic analysis of CSO related

impacts can be made,

the Board concludes that

a Phase 111—type

study of CSO related impacts

on

the receiving streams

in the

77-22

---

—3—

LaSalle area would

be of little utility

in relation to the costs

involved.

In other words, the cost and time involved

in having

LaSalle complete

a Phase

III Study would not be justified

in

relation to the results obtained.

In addition,

the Board does

have data on CSO—related impacts which were provided

in LaSalle’s

Phase II Study

——

Preliminary Stream Inspection

——

which enables

the Board

to adequately evaluate the CSO problem

in LaSalle and

the related impacts on the receiving streams.

For these reasons,

therefore,

the Board

finds that LaSalle has satisfied

its

justification burden pursuant to Section 306.361(d)

and while

such justification should have been established

in the petition

itself,

the Board believes that

in the case of LaSalle, such

justification, as

a practical matter, could only be supplied

at

hearing.

BACKGROUND

The

City of LaSalle

is located

in LaSalle County along both

sides of

Illinois Route

351 from the north bank of the Illinois

River

to

a point

just south of Interstate Route

80.

The Illinois

River

flows from east to west along the south boundary of the

community.

The City’s wastewater treatment plant

(WWTP)

is an

existing primary treatment facility constructed

in the 1950’s.

A

secondary treatment facility consisting of conventional activated

sludge was completed

in 1977.

The plant was designed

for an

average flow of 2.2 MCD and

a maximum flow of

6.0 MGD.

The City’s sewage collection system consists

of two sub-

systems.

The north combined sewer

sub—system has one overflow

which discharges downstream from the

M

& H Zinc Company property

to

a ravine stream

bed.

The stream bed

(or “draw”)

directs flow

to the Little Vermilion River

and thence along the Little

Vermilion River

to its confluence with the Illinois River.

The

south

combined sewer sub-system has one overflow which discharges

at the south end

of Creve Coeur Street

to the Illinois

& Michigan

Canal

(I

& M Canal).

ENVIRONMENTAL IMPACT

Flows in

the north system are conveyed

to the Eleventh

Street Pump Station which allows

for combined sewer overflows

to

discharge through the

M

& H Outfall Sewer.

The sewer

leading

to

the outfall extends about 2,000 feet easterly through the M

&

H

Zinc Company to the point of discharge on a draw about 500 feet

upstream from the Little Vermilion River.

Any flow from the

outfall must pass through the draw before entering the river.

The sewer

is

a circular brick sewer

in extremely poor repair

and

major segments

are washed out.

The area around

the draw is zoned

for heavy industrial

and

is considered

too inaccessible and

overgrown to have

a practical land use.

The Little Vermilion

River

is used

for fishing,

hiking

and other

human contact

activities.

77-23

---

—4—

In addition

to CSO discharges, dry weather discharges occur

at this outfall

and are believed

to be attributable to both

groundwater

infiltration and operational deficiencies at the

Eleventh Street Pump Station.

The groundwater infiltration

is

believed

to be caused by the collapse of the

sewer

in two places

to form large

sink holes.

R. at 61.

Chemical analysis of the

discharges from the outfall indicated the presence of elevated

heavy metals concentrations

(iron, lead, manganese and

zinc)

thought

to

be due

to residual concentrations in the

soil from the

previous operation of the M

&

H Zinc Company for approximately

70

years.

This facility ceased operations approximately eight years

ago.

R.

at

62. This infiltration can only be controlled by

renovation or reconstruction of the sewer.

Dry weather discharges are also caused by the City’s

operational protocol

for

the Eleventh Street Pump Station.

While

the pump station

is capable of handling all dry weather flows,

storm flows have flooded the station previously,

creating

a

serious electrical safety hazard.

Accordingly,

the City has

a

practice of closing

a certain valve, which allows flow to

the

pump station,

at the end of each work

shift

in the afternoon and

opening

the valve each morning.

The valve

is also closed when

rain begins or

is imminent.

When the valve

is closed

flow backs

up and

is consequently relieved by going out the

M

&

H Outflow

Sewer.

The City plans

to eliminate

the pump station and

construct a new diversion structure and gravity sewers

to

transport dry weather

flow without pumping.

In the interim,

short—term measures

to eliminate the problem include installation

of

a high level

alarm signal

and

an o~utsidecircuit breaker

to

shut off power.

R.

at 61—63.

Inspection of the

M

&

H outfall revealed

the presence of

sludge on the surface of

the stream bed channel;

the sludge was

observed

to

be

mixing

with

the

Little

Vermilion

River

at

their

confluence.

However,

the

sludge

was

believed

to

be

attributable

to the dry weather discharging which occurs.

Log jams

in the

stream bed contained small pieces of sewer borne debris.

R.

at

66—67.

The Creve—Coeur Street

sewer extends about

925 feet

southerly from the sewer

system under

a building used

for

manufacturing to the point of discharge on

the

I

& M Canal.

The

discharge point

is approximately 3,000 feet upstream from where

the canal

joins

the Illinois River.

Most of the area in the

vicinity of the discharge is privately owned

and

is zoned

for

heavy industrial.

The City states

that because of the ongoing

manufacturing

on the north side of

the canal

and

the swamp—like

low lands on the

south

side of

the canal,

the area has limited

access with limited actual or potential human contact.

Although

the City states that the portion

of the canal designated

for use

as

a “nature study

area” has its downstream terminus

a

few

thousand feet upstream from

the CSC discharge,

a map delineating

77.24

---

—5—

the boundaries

of the

National

Heritage

Corridor

indicates

that

all

of

LaSalle

including

the

CSO

discharge

lies

within

the

corridor

boundaries.

See

Illinois

and

Michigan

Canal

National

Heritage

Corridor

map,

H.O.

exhibit

1.

The

City

states

that the portion of the canal

to which

the

outfall

discharges

is

a

backwater

of

the

Illinois

River

which

derives its flow from surface runoff,

storm sewers,

CSO

discharges

and

occasionally

from

excess

flow

over

Lock

15.

The

City asserts that the outfall

“probably has only a minor impact

on

the

Canal,

the

river

and

the

river

valley

in

general.”

Pet.

at

9.

The Agency disagrees with this statement citing

a study

prepared

for

the

City

which

concluded

that

deposits

in

the

canal

reduce

the

aesthetic

and

recreational

value

of

the

lower

portion

of the canal during

normal

to low river

levels.

The

study also

stated

that low dissolved oxygen

levels

in the canal

limit

the

fish life and fall below levels required by water quality

standards.

See City Exhibit

10

at

II

C.

Similarly,

the Agency expressed concern about the impact of

the M

& H outfall, citing the same study which stated that the

discharge

of

raw

sewage

and

the

condition

of

the

sewer

line

were

health and safety hazards.

Id. at

I

F.

In addition, Agency

sampling

for

five

heavy

metals

revealed

dramatic

concentration

increases

downstream

of

the

outfall.

On Agency inspections of both outfalls, under dry weather

conditions,

continuous gray discharges were observed.

Sewage—

related

debris

was

apparent

at

both outfalls and sludge deposits

and sewage odor were apparent

in the stream bed tributary to

the

M

&

H outfall.

No odor or sludge was apparent of the Creve

Coeur

outfall on

this occasion but had been observed

on other

occasions.

R.

at

10.

The Agency characterized these

environmental

impacts

as

“severe” but attributed many of the

problems “at least partially

due

to)

the result of dry weather

flows.”

COMPLIANCE OPTIONS

To achieve full compliance,

a

66 inch gravity

sewer

would

need

to be constructed

in the north system

to carry a first flush

rate of

140 MGD for

a one year

design

storm

to

a

new

diversion

structure.

Flows above this rate would continue

to discharge at

M

&

H outfall.

From the proposed diversion structure, dry

weather

flows would be conveyed

to the WWTP, first

flush would

be

conveyed

to

a storage basin

for later

treatment and additional

flows up

to 10

times dry weather flow would be conveyed

to

a new

primary clarifier and chlorination facilities.

77.25

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—6—

In the south system,

facilities would

be constructed

for the

retention of first flush

and primary treatment and disinfection

of

10 times dry weather flow as well

as

a sewer

to connect the

system

with

the

north

system

at

a

point

denoted

as

D—l.

The

total capital cost of this alternative

is $11,599,000 and would

require an increase of approximately $36.30

in the average

monthly residential user’s bill.

The second alternative contemplates similar facilities

in

the

north

system

except

that

a

storage basin would not be

constructed

to capture

first

flush.

In the south system,

a

diversion

structure

would

be

constructed

at Point—Cl

to insure

that no overflow occurs through the

Creve Coeur outfall until

the

treatment plant reaches maximum wet weather capacity.

This

alternative would require

a capital expenditure of $7,343,000 and

an increase

in sewer rates of $22.38.

Alternative

3

is

a modification of alternative

2 and

contemplates

a diversion structure at point C—i

in the south

system and

a 66

inch sewer

in the north system

to divert flows

to

the

south.

It does not include primary clarification and

chlorination facilities.

This alternative would require

a

capital expenditure

of $5,902,000

and

an increase

in residential

sewer rates of $17.49.

Alternative

4

diverts

north

system flows up

to 6.7 times

average dry weather

flow (ADWF)

(7.6 MGD) southerly

to point D—l

by a new 24 inch transportation sewer; higher

flows would

continue

to overflow through the M

&

11 outfall.

7.6 MCD was

selected becauCe

this equals the maximum treatment capacity of

the existing plant

(9.1 MGD) less the present ADWF

(1.5 MGD).

Thus,

it

is the maximum storm flow which can be treated

at the

existing plant.

A diversion structure would

be constructed at

point C—l in the south system to direct maximum wet weather flow

to the existing plant.

This

is the proposal urged by the City as

the recommended alternative.

It would require

a capital

expenditure of

$3,247,600 with an average

increase of $9.77

in

the residential

user rate

for

a total

residential user rate of

$15.48.

Each alternative provides for

increasing

the amount of wet

weather

flows

to be transported

and

treated.

Dry weather flows

will

be eliminated.

Only alternative

4 contemplates

rehabilitation of the M

& H outfall

sewer at

a cost of

$585,000.

The Agency questions the City’s choice of

a

24

inch

sewer

under

alternative

4 to convey flows

in

the north system,

since

there

is the potential

for additional growth

at the east

end of the city.

The cost of the

24

inch

line

is $512,500,

a

36

inch line

is $643,000 and

a

66 inch line which would eliminate

all once

in one year

flows through the outfall

is $2,402,000.

The Agency stated its preference

to see

a

36

inch line.

A

36

inch sewer would accommodate

up to four times

the

first flush

77-26

---

—7—

flow that the

24 inch sewer could handle.

R.

at 96,109.

The

City stated that

it would acquiesce

to installing the

36 inch

sewer,

acknowledging that the

24 inch sewer would handle “the

situation as

it now exists.”

(R.

at 96).

While

a

66 inch line

would

limit CSO events at the M

&

H outfall

to only one per year,

CSO events at point

ID—i would increase to 31 since the increase

in size and carrying

capacity of the sewer

line would result in

the delivery of flow in excess of the hydraulic capacity of the

treatment plant.

The projected number

of CSO events for the various

alternatives at the M

&

H outfall

is as follows:

CSC Events

Per Year

at

CSO Events

Proposed

Existing M

&

H

Per Year at

Reduction Over

Alternative

Outfall

Proposed Point D—l

“No Action”

No Action

38

0

0

Alt.

4

32

0

6

Alt.

3

1

31

6

Alt.

2

1

24

13

Alt.

1

1

0

37

At

the

Creve

Coeur

outfall,

the

projected

number

of

CSO

events

for each alternative

is as

follows:

CSC Events

Per Year at

Proposed

Existing Creve

Alternative

Coeur Outfall

No Action

32

Alt.

4

32

Alt.

3

32

Alt.

2

32

Alt.

1

1

AGENCY RECOMMENDATION AND BOARD CONCLUSIONS

The Agency points out that a large portion of the proposed

expenditure

under

alternative

4 of $3,247,600

(1985 dollars)

is

related

to the elimination of dry weather

flows and

the

reparation of collapsed sewers

and

it

is therefore misleading

to

think of the entire amount as being

related

to CSO impacts.

(R.

at

13).

The Agency agrees that while

these improvements should

certainly be made there

are too many unknowns and uncertainties

for

any

permanent

relief

to

be

granted.

The

Agency

is

of

the

opinion that substantial

improvements

to water

quality are likely

to result after

implementation of the City’s preferred

alternative but questions whether those

impacts will

be

77-27

---

—8—

diminished

to a minimal level.

The Agency would prefer that the

effect of the improvements be evaluated upon completion before

any permanent relief

is granted.

The Board

shares the Agency’s concerns and generally agrees

with its proposed temporary exception approach.

The Board will

time

the temporary exception

to the City’s implementation

schedule included

in its Municipal Compliance Plan

(Exh.

6 at

18)

which

lists completion as July 1,

1988.

In the absence of

information

to the contrary, the Board will assume that this

deadline also applies

to the CSO upgradings.

However, the

temporary exception will

be timed

so as to allow two years

from

the July 1,

1988 completion date

to gather post—full operation

data.

The

Board

will

also

retain

jurisdiction.

The Board will provide for constraints on expansion of the

service

area,

but

allow

the

City,

by

way

of

motion

for

modification,

to request the Board

to allow hook—ons beyond

the

residential 15 Population Equivalent

(PE) limitation.

(See

Paragraph

3

of the Order).

The Board cautions the City that

it

must submit

justification

data

of

sufficient

specificity

for

the

Board

to evaluate the hydraulic effects of the new loadings on

the system

including upstream—overflows, and the effects on the

quality of the overflows.

The Board notes that the relief

restricted

to those substantive requirements for treatment of

CSOs and not

to relief from water quality standards.

In

summary,

the Board

finds

that,

taking

into account the

factors contained

in 27(a)

of the Act, the City of LaSalle has

not

justified

a

permanent

exception,

but

has justified

a

temporary exception, with conditions.

ORDER

1.

Except as provided

in Paragraph

2 of this Order, the

City of LaSalle

is granted

a temporary exception until

July

1,

1990 from 35

Ill. Adm. Code 306.305(a)

regarding

the

first flush of storm

flows

and

from 35

Ill.

Adni.

Code 306.305(b).

2.

If, on or before March

1,

1990,

the City of LaSalle

fails

to submit an amended petition

for exception, this

temporary exception will terminate on March

1,

1990.

3.

During this temporary exception period the City

of

LaSalle,

in

consultation

with

the

Agency,

shall

construct and operate the improvements

to

its wastewater

collection system and wastewater

treatment plant as

described

in Alternative

4 by July

1,

1988,

except that

the City shall

install

a

36

inch sewer

in the north

system.

77-28

---

—9—

4.

Unless authorized

by the Board upon a petition

for

modification of this order, there

shall

be no expansion

of

the service area tributary

to the combined sewers

except

for residential hookups that do not exceed

15

population equivalents as defined

in Ill.

Adm. Code

301. 345.

5.

The City shall continue its monitoring of

the combined

sewer overflows on a weekly basis and after every major

rainfall and make written reports thereon and take

corrective actions as necessary.

In addition, the City

shall monitor

the proposed

“emergency” outfall on a

weekly basis and after every major

rainfall and prepare

written reports thereon

to determine whether

the outfall

is

in fact used on

an emergency basis.

6.

This grant of exception does not preclude

the Agency

from exercising

its authority to require as a permit

condition

a CSO monitoring program sufficient

to assess

compliance with this exception and any other

Board

regulations and other controls,

if needed,

for

compliance,

including compliance with water

quality

standards

7.

This grant

of exception is not

to be construed as

affecting the enforceability of any provisions of this

exception,

other

Board regulations,

or

the Environmental

Protection Act.

8.

The Board will retain jurisdiction

in this matter.

iT

IS SO ORDERED.

.

D. Dumelle and

3.

G. Anderson concurred.

I,

Dorothy

M.

Gunn, Clerk of

the Illinois Pollution Control

Board,

hereby certify that the~ove Opinion and Order was

adopted

on the

/~-

day of

__________________,

1987, by a vote

Dorothy M.

c~41hn,Clerk

Illinois Pollution Control

Boarã

77-29