ILLINOIS POLLUTION CONTROL BOARD

October 12, 1984

IN THE MATTER OF:

)

)

PROPOSAL

OF

THE

ILLINOIS

POWER

)

R83—ll

COMPANY

FOR

A

SITE—SPECIFIC

)

EFFLUENT

RULE

CHANGE

(PROPOSED

)

?~ME~DVCNT

‘PU

LL,

ADM~ CODE,

)

m~r~j~

35,

PART

304,

SUBPART B)

)

PROPOSED

EWLE,

SECOND NOTICE.

P1~O~3SED

OPINION AND ORDER OF THE

BOARD

(by

B.

Forcade):

On

April

27, 1984, the Board proposed to add a new S304.209

to

Subpart

B of Part 304 of Title

35

of the Illinois Administrative

code~

This

new section would provide site—specific relief to

Il:Lincis

Hower

Company (“IPC”)

for their Wood River Station.

First

notice

of

this proposal was published at

8 Iii. Reg.

8116,

on

June

8,

1984.

The first notice comment period expired on July

23,

1984.

Under

the

rule

proposed

at

first

notice, the applicable

total

suspended solids

(TSS) effluent limitations for the facility’s

ash

pond

system

effluent

would

be

30 mg/i as an average of daily

value

for

thirty consecutive days and 100 mg/i

as

a

daily maximum.

Comments

were

received,

during the first notice

period,

from the

Illinois

Environmental

Protection Agency (“Agency”)

and from IPC.

The

Administrative

Code Unit submitted

a

comment on June

11,

1984,

concerning

Illinois Register first notice format.

The

Agency,

in

its

comment,

agrees that IPC is entitled to

site~specific

relief,

The Agency, however,

disagrees as to the

degree

of

relief

that should be granted.

The Agency believes

that

the

proposed 100 mg/i daily maximum

is

less stringent than

the

levels

of treatment that have been shown to be achievable.

Three

years

of

data indicates that the system can consistently

achieve

effluent under 50 mg/i.

The Agency believes this demon—

strated,

ability

should

be

the basis for the site—specific rule.

IPC,

in

its

comment, argues that the ash pond treatment

system

is

a dynamic process that is influenced by many factors,

including

factors

not within IPC’s controle

Thus,

IPC contends,

the

proposed

daily

maximum of 100

mg/i

provides a reasonably

achievable

limitation that will provide relief over the

life

of

the

system

and

latitude during periods of uncontrolable fluctuation.

The

Board

finds

that the 50 mg/i daily maximum limitation is

the

more

appropriate standard and is better supported in the

recorth

Data

submitted at hearing by IPC clearly shows

the

system’s

performance

capability since construction was completed in May of

1982

(Petitioner’s

Exhibit

9).

Effluent has not exceeded

50

mg/i

for

three

years.

In

support of the

100

mg/i standard, IPC has

argued

that

it

is

more likely that the

50

mg/i standard

will

60-281

---

2

be violated than the 100 mg/l standard (R~l46)~ ~hile this is

most certainly a true statement,

it is also likely that the

system will continue to achieve TSS concentrations below

50

mg/l.

Site~’speeifiarelief here cannot be based on abstract and

unsupported statements regarding “probabilities” where the data

clearly supports another conclusion,

IPC testified that it is probable that as the ash lagoon

system fills over time, TSS concentrations will increase

(R,

l36)~ iPc, however, also testified that these future

concen-

trations are presently unquantifiable.

Because of this uncer-

tainty and because of the ten to twenty year life expectancy of

the lagoon system, the Board is unable to fashion a TSS limitation

that will account for potential changes in the lagoon system’s

efficiency in the distant future.

At present,

there is no support

in the record for any limitation other than 50 mg/i.

IPC may

petition the Board for a variance from the proposed rule or

propose an amendment to the rule if the performance of the ash

lagoon system changes significiantly in the future,

While

site~specificrules are intended to provide long—term relief,

there are limits to the Board~sability to do so where future

conditions cannot be predicted.

A more important factor, when

creating site~specificrules,

is to base them on system

capabilities and limitations as reflected by the available data,

Today~srule reflects this principles

ORDER

The Board directs that second notice of the following rule

be submitted to the Joint Committee on Administrative Rules:

TITLE

35:

ENVIRONMENTAL PROTECTION

SUBTITLE C:

WATER POLLUTION

CHAPTER I:

POLLUTION CONTROL BOARD

PART 304

SITE—SPECIFIC

RULES

AND EXCEPTIONS

NOT OF GENERAL APPLICABILITY

Section

3

O4~209

~

~hares

Th~nonthedischare~lSusendedSoiids

con-

~

from the_ash p4nd system of Illinois Power C~p~ny’sWood River

Station, located in East Alton

Illinois,

Instead

the concen—

~xceed30m1asan

avera e of dail

values for thirt

(30) consecutive

da

s

and

60-282

---

3

IT IS SO ORDERED,

I, Dorothy M. Gunn,

Clerk of the

Illinois Pollution

Control

Board,

hereby certify that the

above

Opinion

and

Order

was

adopted

on the

42~!~

day of

~

,

1984 by

a vote of

46

L~’,4j

Illinois Pollution Control Board