ILLINOIS POLLUTION CONTROL BOARD

November

11,

1971

COMMONWEALTH EDISON COMP~Y

v.

)

PCB 71—129

ENVIRONMENTAL PROTECTION AGENCY)

SUPPTEM~HTALOPINION

(by Mr. Kissel):

Commonwealth Edison Company has filed a Petition for Clarifi-

cation and/or Modification of

the Board’s Order in the

case

of

Commonwealth

Edison v.

EPA,

PCB 71—129, decided October 14,

1971.

Edison contends that a mutual inconsistency exists between

paragraphs

5(a)

and 5(c) of the Board’s Order.

We agree.

Paragraph

5(a)

imposes sufficient limitations upon the operation of Powerton

so that its use

and the consequent emissions will be minimized.

The

conditions imposed in the now—repealed

5(c) would have prevented the

operation of Powerton to

the

50

capacity

it must reach in order to

provide Edison power to meet daily peak

load plus operating reserve,

Paragraph

5 (b) continues

in effect the dispensation from the condi-

tion of

5(a) when necessary to prevent icing on the transmission

lines or to provide first contingency protection to

the Humboldt

Park substation.

ORDER

Paragraph

5(c)

of the Board’s Order in the case of Commonwealth

Edison

v,

EPA, PCB 71-129,

is hereby deleted.

Paragraph

5 shall

now

read as

follows:

5,

At the Powerton Station,

for units

1,

2,

3 and

4,

to October 15,

1972, subject to extension until October 31,

1974, provided that:

(a)

?owerton

shall

be

the

last

units

on

the

Edison

system

committed

to

service

and the first taken

after

the

daily

peak period has passed.

Powerton

shall

be committed only with suffi-

cient lead time

to ensure the unit’s availability

for the daily peak period.

When Powerton capac-

ity

is required to meet the predicted daily peak

load plus

the operating reserve,

the station

will be initially loaded to approximately

50

capacity.

Before the remaining capability of

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the Powerton units will be utilized,

all

other units on

the Edison system

--

including

the fast-start peaking units

—-

will be brought

to fu—1 operating load, exclusive of emergency

capability.

(b)

The restrictions set forth in paragraph

5(a)

above shall

not apply if weather conditions

which may cause icing on the transmission

lines exist or if Edison’s projected daily

peak

load equals or exceeds

70

of the pro-

jected annual peak load.

I, Christan Moffett, Acting Clerk of the Illinois Pollution

Control

Board, certify that the Board adopted the above Opinion

and Order on this

//

day of November,

1971.

~

~~)\

/2)

~

Christan Mof~e

Acting Clerk

3

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54