ILLINOIS POLLUTION
CONTROL BOARD
October 10, 1972
ILLINOIS POWER CO. (HENNEPIN STATION)
)
v.
)
#72—297
ENVIRONMENTAL PROTECTION AGENCY
)
Opinion of
the
Board
(by ~4r.Currie):
In Illinois Power Co. v. EPA,
#71—193, 2
PCB
547
(Sept.
30, 1971), we approved a control plan that envisioned erection
of a 99 precipitator on Hennepin Unit 2
by
June 30, 1972,
which would cause particulate emissions
from the two Hennepin
units operating at the same time and discharging through a
single stack to comply with the then applicable regulations.
The opinion observed that the
company’s
ability to meet the
standard by controlling only one of
the
two
units
“demonstrates
the laxity of the existing standard,” which has since been
tightened with a future effective date. PCB Regs., Ch. 2,
Rule 203(g). To meet this
new standard, and recognizing that
it
may
on occasion be necessary
to operate Unit #1 alone when
#2
is temporarily inoperable, Illinois Power now proposes to
install a 99.5 precipitator on Unit #1 by June 30, 1974,
eleven months before the effective date of the new standard.
A variance is sought to allow use of Unit
#1
by itself, when
necessary, before that
date, although this will result
in
emissions exceeding those
allowed by the presently effective
standard.
The Agency agrees that such permission should be granted
when indispensable to avoid interruption of electric service,
and we note that the total weight of emissions during such a
period, while in violation of the standard, will be less than
those lawfully emitted when both units operate at once. The
company agrees to other conditions suggested by the Agency to
assure that there is a real need for the use of Unit #1 by
itself. The Agency’s principal concern was that perhaps several
mciths
could be cut from the schedule for precipitator con~
str~ction,but upon the submission of further affidavits by
the company the Agency agrees that the schedule is reason—
able and we accordingly approve it.
ORDER
Illinois Power
Co.
is hereby granted a variance allowing
Darticulate emissions from Henneo±nUnit #1 in excess of those
5
—
645
—2--
permitted by Rule 2-2.21 of the Rules and Regulations Govern-
ing the Control of Air Pollution until October 10, 1973, sub-
ject to extension upon a proper showing until June 30, 1974,
provided the following conditions are met:
1. That the Variance shall apply only when all of the follow-
ing requirements are met:
a. Unit #2 and its precipitator are not in operation
due to malfunctions or necessary maintenance;
and
b. Interruptible gas is not available at the residential
rate to Unit #1; and
c. Demand conditions for electrical supply, or the main-
tenance of spinning reserves, or the maintenance of
adequate voltage on the Petitioner’s electrical net-
work is such to require the additional generating
capacity of Unit #1, and
d. Operation of
Unit
#1 is necessary until other con-
trolled units of Petitioner
or
other controlled
systems can
be brought into operation.
2,
That
records he submitted along with the required program
report
stating the date, length
of operation, and reasons
for nbc operation of
Hennepin Unit
~l
in violation of
the
eresent :~articujate emission
regulations.
3. That Petitioner maximize
uti:Lization of its Baldwin Unit,
flood
River
Gnits.
44
and #f
•
and
Havana Units (all of
which are preseni:iy in compliance with particulate emission
regulations) before utilizing Hennepin #l~
That
Petitioner
utilize Hennepin #1 in preference
to
Wood liver Units 41, #2 and #3 until Wood River Units
41 #2 and #3 become in compliance with particulate
emission
regulations.
3. That emissions from Hennepin Unit #1 shall receive the
best practicable control consistent with existing control
equipment;
6.
That Illinois Power shall diligently pursue
the construction
of the Unit #1 precipitator
iii accordance with its
own
schedule, as fol1ows~
Completion of design
December, 1972
Construction of model and
model testing
March, 1973
Submission of
Model test
report to consulting
engineers
June, 1973
Flue gas duct design
June,
1973
Conunencement of on-site
construction
July, 1973
Shipment of precipitator
Oct. -Dec.
1973
Construction and Performance
Test Completed
June
30, 1974
,
Christan Moffett, Clerk of the Pollution Control BoarclL
certify that the Board adopted th~above Opinion this ~
day of October, 1972, by a vote of ~