ILLINOIS POLLUTION CONTROL
BOARD
October
4,
1979
ALLIED CHEMICAL CORPORATION,
)
Petitioner,
v.
)
PCB 79—101
)
ENVIRONMENTAL PROTECTION AGENCY,
)
Respondent.
OPINION OF THE BOARD
(by Dr. Satchell):
This matter comes before the Board upon a petition for
variance filed April 26, 1979 and amendments filed June
1 and
August 29,
1979 by Allied Chemical Company
(Allied).
The
petition and amendments request a variance from the requirements
of Rule 105(c),
204(f) (1) (A)
and 204(f) (2) (A)
of Chapter
2:
Air
Pollution.
Rule 105(c)
provides for operation of an emission
source during malfunction, breakdown or startup.
The sub-
sections of Rule 204(f)
set emission limits of 2000 ppm for
sulfur dioxide and 0.15 pounds of sulfuric acid mist per ton of
acid
manufactured.
Allied waived its right to a hearing and
the Environmental Protection Agency
(Agency)
filed
a recommendation
on July 19,
1979 and an amended recommendation on September 18,
1979.
The latter recommended that the variance be granted with
conditions.
On September 20, 1979,
pursuant to Allied’s motion
for expedited consideration, the Board entered an Order granting
the variance with conditions similar to those recommended by the
Agency.
Allied operates a three—unit sulfuric acid plant at its Calumet
Works in a mixed industrial and residential area south of Chicago.
The plant produces
a waste gas stream which is passed through a
Weilman—Lord sulfur dioxide recovery system which is designed to
handle 35,000 scfm with 3000 to 5000 ppm sulfur dioxide and 2100
mg/rn3 acid mist and which recovers
sulfuric acid and converts
the sulfur dioxide to
a useable byproduct.
When oper4ting, the
system emits 20 to 500 ppm sulfur dioxide and 15 mg/ma acid mist
through
a 120 foot stack
(Amended Rec.
2).
The system has been
in service for six years and is in need of major repairs which are
scheduled for the month of October,
1979.
Rather than shut the
plant down for this period, Allied proposes to duct its emissions
directly to the atmosphere through a fifty-five foot stack.
Air
Rule 105(c)
provides for continued operation to prevent injury to
35—463
—2—
persons,
severe damage to equipment or to provide essential
services.
Even if this were
a malfunction or breakdown, the
Agency could not grant permission under Rule 105(c)
to operate
in violation of standards solely for the economic benefit of the
operator.
The Agency figures the uncontrolled average emissions at
2700 ppm or 866
lbs/hr sulfur dioxide and 2100 mg/rn3 or 236
lbs/hr acid mist.
Maximum emissions could amount to 1284 and
642
lbs/hr,
respectively.
The Agency has predicted the results
of the uncontrolled emissions on air quality for 400 points
in
a 20 x 20 kilometer area by means of an Air Quality Short Term
Model--Running Average Version.
The results of this modeling
indicated that
the
24—hr averaging time was the most constraining
and that,
after eliminating the single highest value,
the second
highest 24-hr average ambient air concen~rationresulting from
uncontrolled emissions would be 604 mg/rn
.
Adding the background
concentration, the Agency arrived at a predicted maximum 24—hr
average concentration of 624 mg/rn3 sulfur dioxide.
The attain-
ment status of the area around the plant for the sulfur dioxide
National Ambient Air Quality Standards
(NAAQS)
is listed as
“Cannot Be Classified”
43
Fed.
Reg.
8987
(1978)).
The 24—hr
NAAQS is
365 mg/rn3 sulfur dioxide.
The Agency model also predicted that excursions above the
NAAQS
for sulfur dioxide will occur from the
fifty—five foot
stack only when the wind blows in excess of fifteen knots
in one
direction for more than three hours and the sulfur dioxide
emission rate is
in excess of 736 lbs/hr.
Accordingly, the
Agency recommended that the variance be conditioned on a wind
and sulfur dioxide monitoring program.
The Board also required
that Allied limit its emissions when the wind exceeded fifteen
knots
in one direction for more than three hours.
Allied will
be expected to reduce its process rate
if necessary to achieve
this.
Bringing the plant to
a cold shutdown may cause layoffs and
damage to equipment and will result in a startup with high energy
consumption and emissions.
The Board finds that there would be,
under the particular circumstances of this case,
an arbitrary and
unreasonable hardship in requiring compliance with the emission
standards during the maintenance shutdown of the waste gas recov-
ery system.
This variance may be granted only if consistent with
the Federal Clean Air Act
(42 U.S.C.
§7401 et seq.
and
§
35 of
the Environmental Protection Act).
Since it
wilT
extend beyond
July 1,
1979,
it will be submitted to the U.
S. Environmental
Protection Agency as an amendment to the State Implementation
Plan.
35—4
64
—3—
This Opinion, supporting the Order of September
20,
1979,
constitutes the Board’s findings of fact and conclusions of
law in this matter.
Mr. Werner concurs.
I, Christan L.
Moffett, Clerk of the Illinois Pollution
Control Board, hereby
e tify the above Opinion was adopted
on the
~
day of
_________,
1979 by
a vote of
______
Christan
L. Moff
i-~yrC
erk
Illinois Pollution ~e’ontro1Board
35—465