ILLINOIS POLLUTION CONTROL BOARD
October
 9,
 1986
COMMONWEALTH EDISON COMPANY,
BYRON GENERATING STATION,
 )
Petitioner,
v.
 )
 PCB 86—168
)
ILLINOIS ENVIRONMENTAL
 )
PROTECTION AGENCY,
 )
Respondent.
OPINION AND ORDER OF THE BOARD
 (by J.D. DuTnelle):
This provisional variance request comes before
 the Board
upon
 an October
 8,
 1986 Recommendation of the Illinois
Environmental Protection Agency (Agency).
 The Agency recommends
that a 45—day provisional variance be granted
 to
 the Commonwealth
Edison Company
 (CWE)
 from 35
 Ill.
 Adm. Code 304.120(a)
 as
 it
pertains to
 the biochemical oxygen demand
 (BOD)
 and
 total
suspended solids
 (TSS)
 effluent requirements of the Petitioner’s
NPDES Permit for Outfall 001(b)
 (Sewage Treatment Plant
Discharge) during the
 time period
 in which portions of the sewage
treatment plant are bypassed for essential maintenance and
repairs.
The Petitioner’s Byron Generating Station
 is a nuclear—
fueled steam electric generating plant located
 in Byron,
 Ogle
County,
 Illinois.
 At this nuclear
 power pant,
 a maximum
capacity of 2350 megawatts of electric power will
 be provided by
two pressurized
 water
 reactors.
 There
 is one 1175 megawatt
electric unit presently
 in operation,
 while the other electric
unit
 is still under construction.
 (Pet.
 1—2).
 Commonwealth
Edison Company owns and operates both sanitary and
 industrial
wastewater
 treatment
 facilities
 in
 conjunction
 with
 its
 Byron
Generating
 Station.
 The
 Petitioner’s
 sanitary
 wastewater
treatment facilities, which are the subject of the instant
provisional variance request, consist of flow equalization
equipment, grit removal, flow measurement,
 final claifiers,
aeration tanks,
 sand filters, disinfection, sludge drying beds,
and aerobic digestion.
 (Rec.
 1).
 These facilities have
 a design
average flow of 0.046 million gallons per day
 (MGD)
 and treated
effluent from
 the sewage treatment plant discharges into
 the Rock
River via the generating station’s cooling tower blowdown lines
after being
 combined with effluent from the
 industrial wastewater
treatment facilities.
 CWE presently discharges wastewaters
pursuant to
 its NPDES Permit No.
 IL 0048313 which was just
 reissued on April 28,
 1986.
 (Pet.
 1).
73-73
—2—
The reason that corrective maintenance work
 is vitally
important
 is that “cracks
 in welds between the various chambers
of the old activated sludge plant have been observed” while
“cracks
 in the bottom are suspected”.
 (Pet.
 2).
 Moreover,
 the
coatings on the chamber walls are corroding, thereby jeopardizing
their
 integrity.
 During the requested provisional variance
period,
CWE
intends to
 repair
 the welds, sand blast
 the walls,
and recoat the chamber walls.
 The units not undergoing
maintenance will remain
 in
 service
 to provide some treatment of
the domestic wastewater.
 (Pet.
 1—2; Rec.
 2).
 The Petitioner
emphasizes the necessity for essential maintenance by contending
that,
 if the weld (and other)
 repairs are not performed soon,
“the plant could be idled
 for
 a much longer reconstruction
period”.
 (Pet.
 2).
As alternatives to partially bypassing
 its sewage treatment
plant,
 the company has considered two primary alternatives:
 (1)
to shut down electric plant operations
 and thereby eliminate
 all
waste
 inputs,
 and
 (2)
 to shut the sewage treatment plant down
 and
use portable tanks
 for the storage of sewage generated during
 the
shutdown.
 (Pet.
 2; Rec. 2).
 However, the Petitioner believes
that
 a shutdown of its electric plant operations
 is not feasible
since
 it would necessitate the complete shutdown of its 1175
megawatt electric unit which
 is currently generating power
 on a
24—hour
 a day, 7—day
 a week basis, thereby costing
CWE
 (and
ultimately its
 customers
 via
 increased
 electric
 rate
 charges)
 up
to $1,000,000
 per day in
 fuel charges and electric power
replacement costs.
 (Pet.
 2).
 Moreover,
 its sewage treatment
plant receives wastes even when the electric plant is not
operating,
 so that a complete
 elimination of waste
 inputs “could
only be accomplished by virtually deserting the site and this
 is
clearly impossible.”
 (Pet.
 2).
Similarly,
 the shutdown of its sewage
 treatment plant and
use of
 portable tanks
 for
 the storage of
 sewage generated during
the shutdown
 is not practical “because of the amount
 of storage
that would be required and the difficulty that would arise later
in trying
 to
 treat the
 stored waste
 along with the normal
treatment load”.
 (Pet.
 2).
 In
 its Recommendation,
 the Agency
has stated that it agrees with the Petitioner’s “assessment of
the alternatives and the remedial method selected”.
 (Rec.
 2).
To minimize any adverse environmental
 impact while repairs
to its sewage treatment plant are being performed,
 the Petitioner
plans
 to
 reduce the level
 of pollutants
 in its discharge by:
 (1)
performing
 the essential maintenance and
 repair work
 in stages,
so that units
 (such as the digester) not normally used for
treatment will be reconfigured
 to provide some treatment
 at all
times,
 and
 (2) providing temporary tanks
 for chlorination “to
assure uninterrupted disinfection” during the
 time period that
repairs are being
 completed.
 (Pet.
 2).
73-74
—3—
The
 Petitioner
 has stated that it believes that “the
environmental impact
 to the Rock River will
 be negligible due
 to
the relatively small wastewater volumes involved
 (daily average
 flow of the STP
 is approximately 20,000 gallons per day)
 and
because
 the discharge
 is co—mingled with cooling tower blowdown
water
 flowing at approximately 10,000 gallons per second prior
 to
its entry to the Rock River”.
 (Pet.
 2).
 In fact,
CWE
expects
that discharges
 from its sewage treatment plant
 will, during most
of the time,
 still
 be
 in compliance with the requisite NPDES
Permit limits because of
 its partial treatment of sewage wastes
and chlorination of
 its sewage treatment plant discharges during
the time that necessary maintenance work is performed.
 (Pet.
2).
 After carefully evaluating
 the company’s detailed
maintenance plan
 for performing the requisite system repairs,
 the
Agency has indicated that
 it agrees with CWE’s conclusion that
there will be
 a minimal environmental impact.
 (Rec.
 2).
Based
 on limited sampling
 of partially treated sewage which
the Byron Generating Station has collected during the past
several weeks, the Petitioner has requested that interim effluent
limitations
 of 100 mg/l for biochemical oxygen demand and 100
mg/l for total suspended solids from Outfall 001(b)
 should
 be
established during the
 time period that corrective maintenance
work will
 be done.
 (Pet.
 1).
However, the Agency has recommended
 that the Board set
interim effluent limits of
 75 mg/l
 for both BOD and TSS because
CWE
will be providing partial
 treatment while
 the requisite
repairs are being made.
 (Rec.
 2).
 The Board believes that the
Agency’s evaluation of the situation
 is fundamentally cor;ect,
and will therefore set appropriate interim effluent limits
 in
accord with the Agency’s recommendation.
The Commonwealth Edison Company contends that denial of its
requested provisional variance would
 impose
 an arbitrary or
unreasonable hardship because
 it will now be providing partial
treatment to
 the wastewater
 when repairs are made, while
 the
alternative of doing nothing until
 failure of the welds would
probably result in little
 or
 no treatment being provided for
 a
period longer than 45 days.
 (Pet.
 1—3).
The Agency agrees with the Petitioner’s assessment of
hardship and has therefore concluded that immediate compliance on
a short—term basis with
 35 Ill. Adm. Code 304.120(a)
 as
 it
pertains
 to the BOD and TSS effluent requirements of the
Petitioner’s NPDES Permit for Outfall 001(b) would
 impose
 an
arbitrary or
 unreasonable hardship upon the company “since
 Petitioner
 is ready to repair
 the affected treatment units before
total failure occurs
 and will be able
 to provide partial
treatment while the repairs are made”.
 (Rec.
 1—3).
Additionally,
 there
 are no
 federal
 regulations which would
preclude
 the granting
 of the requested relief and there
 are no
73-75
—4—
public
 water
 supplies which would be adversely affected by the
granting of the provisional variance.
 Accordingly,
 the Agency
has recommended
 that the Board grant
 the Petitioner
 a provisional
variance
 from 35
 Ill.
 Adm.
 Code 304.120(a) as
 it pertains to the
Bod
 and TSS effluent limitations
 for Outfall 001(b), subject
 to
various specified conditions.
Pursuant to Section 35(b)
 of the Illinois Environmental
Protection Act,
 the Board hereby grants the provisional variance
as recommended.
This Opinion constitutes
 the Board’s findings of fact and
conclusions of law
 in this matter.
ORDER
The Petitioner,
 the Commonwealth Edison Company (Byron
Generating Station),
 is hereby granted a provisional variance
from 35 Ill.
 Adm. Code 304.120(a)
 as it pertains
 to
 the
biochemical oxygen demand
 and
 total suspended solids effluent
requirements of its NPDES Permit No.
 IL 0048313 for Outfall
001(b)
 (Sewage Treatment Plant Discharge), subject
 to the
following conditions:
1.
 This provisional variance shall
 begin on October
 17,
 1986,
and shall continue
 for 45 days thereafter,
 or
 until the
repairs to
 the sanitary wastewater
 treatment facilities
are completed, whichever
 occurs
 first.
2.
 The Petitioner
 shall
 sample
 and analyze the effluent
discharged
 from Outfall 001(b)
 as required by its NPDES
Permit No.
 IL 0048313.
 Analysis results shall
 be recorded
and submitted
 to the Agency on the requisite monthly
discharge monitoring
 reports.
3.
 Effluent discharged
 from Outfall 001(b)
 shall be limited
to 75 mg/i and 35.5 lb/day for both biochemical oxygen
demand
 and
 total suspended
 solids
 as
 30—day
 averages
during
 the
 time
 period
 of
 this
 provisional
 variance.
4.
 The
 Petitioner
 shall
 notify
 Mr.
 Gary
 Reside
 of
 the
Agency’s Compliance Assurance Section via telephone
 at
217/782—9720 when the repair work
 is started and when
 it
is completed.
 Written confirmation of each telephone
notification shall
 be submitted within
 5 days to the
Agency at the address given
 below:
73.76
—5—
Illinois
 Environmental
 Protection
 Agency
Division
 of
 Water
 Pollution
 Control
Compliance Assurance Section
2200
 Churchill
 Road
Springfield, Illinois
 62706
Attention:
 !‘lr.
 Gary Reside
5.
 The
 Petitioner
 shall
 adhere
 to
 the
 maintenance
 procedure
referred
 to
 in
 its
 provisional
 variance
 petition
 so
 as
 to
provide
 partial
 treatment
 at
 all
 times.
6.
 The Petitioner
 shall operate
 and maintain its sanitary
wastewater treatment facilities so as to produce the best
effluent
 possible
 during
 this
 provisional
 variance
 period.
7. Within
 10 days of the date of the Board’s Order, the
Petitioner
 shall execute
 a Certificate of Acceptance
 and
Agreement which shall
 be sent to Mr. James Frost of the
Agency
 at
 the
 following
 address:
Mr. James Frost
Illinois
 Environmental
 Protection
 Agency
Division
 of
 Water
 Pollution
 Control
Compliance Assurance Section
2200
 Churchill
 Road
Springfield, Illinois 62706
This certification shall have the following
 form:
I,
 (We)
 ,
 having
 read
the Order of the Illinois
 Pollution
 Control
 Board
 in
 PCB
 86—168
dated October
 9,
 1986,
 understand
 and accept said Order,
realizing
 that
 such
 acceptance
 renders
 all
 terms
 and
 conditions
thereto
 binding
 and
 enforceable.
Petitioner
By:
 Authorized
 Agent
Title
Date
73.77
—6—
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
____________
 day of
 ~
 ,
 1986 by a
vote of
_____________
~
 Dorothy
 M.
 n,
 Clerk
Illinois Pollution Control
 Board
73.78