ILLINOIS POLLUTION CONTROL BOARD
June 13, 1985
CIT~OF BELVIDERE,
)
Petitioner,
)
v.
)
PCB 85—81
)
ILLINOIS ENVIRONMENTAL
)
PROTECTION AGENCY,
)
)
Respondent.
OPINION AND ORDER OF TUB BOARD (by W. J. Nega):
This provisional variance request comes before the Board
upon a 1hrne 13, 1985 Recommendation of the Illinois Environmental
protection Agency (Agency). The Agency recommends that a 30—day
provisional variance be granted to the City of Belvidere (City)
to allow the Petitioner to exceed the effluent. limitations in its
NPDES Permit No. IL 0027685 for biochemical oxygen demand (SOD)
and total suspended solids (TSS) while repairs are made to the
sludge collection mechanism in the West Final Settling Tank of
its wastewater treatment plant
(WWTP)
and while subsequent
inspection of the sludge collection mechanism in the East Final
Settling Tank of its WWTP is completed. (Rec. 1).
The City of Belvidere owns and operates a wastewater
treatment facility which has a design average flow of 5.8 million
gallonprimarypersedimentation,day (MCD) andcontactconsistsstabilizationof “screeningactivatedandgritsludgeremoval1
process, secondary sedimentation, tertiary filters, disinfection
and sludge thickening, digestion, and dewatering”. (Rec. 1).
This
WWTP
discharges its effluent to the Kishwaukee River
pursuant to its NPDES Permit authorization.
On May 20, 1985, the drive cage in the Petitioner’s West
Final Settling Tank at the City’s wastewater treatment plant
broke. ThiS resulted in the drive cage, center well, and truss
arm falling to the bottom of the settling tank. (Rec, 1—2),
Additionally, all of the steel bent up on the drive cage thereby
cracking
the
side wall box and center inlet well. To repair this
damage, it is necessary to “cut out and make a whole new drive
cage assembly, weld the center plate and the inlet box walls,
jack up the truss arm and reline, bolt and weld it and check the
run out to make sure it runs true”. (See; attachment to Agency’s
Recommendation). The City has dewatered the West Final Settling
Tank and ascertained that the breakage and other equipment
problems were due to bolt failure and missing field welds which
should have been installed during the initial construction
fifteen years ago. (Rec. 2),
~4-2?1
rortunately, the City was able to properly repair
the
aforementioned damage more rapidly than originally anticipated
and the West Final
Settling Tank was returned to servic~ on June
5, 1985. (Rec. 2). However, the service man who inspected the
damage at the West Final Settling Tank believes that there is a
strong possibility that field welds were not installed on either
final settling tank (i.e., only installation bolts were
installed) and thus it is likely that the East Final Settling
Tank may soon develop the same problems as the west tank.
Accordingly, the petitioner plans to dewater and inspect the East
Final Settling Tank center drive cage as soon as the weather
permits and to install new bolts and properly weld the drive cage
to avoid future environmental problems0 The City intends to run
the West Final Settling Tank for a time period of at least a week
to determine that this settling tank is properly operating before
dewatering the east tank to make the necessary repairs before a
similar failure occurs in the east settling tank. (Rec. 2). It
takes at least a day to drain down the east tank far enough to
expose the steel; about 2 days for the steel to dry sufficiently
to allow adequate welding; at least several days for the
necessary welding and bolt replacement; and approximately a week
for the treatment plant to stabilize after the east settling tank
is put back into service, Such procedures may be delayed by
rainy weather which could preclude starting this work or could
interupt this work while in progress. (See: Attachment 1 to
Agency’s Recommendation),
The Petitioner’s NPDES Permit provides that the City’s
wastewater treatment facilities must meet interim effluent limits
of 20 mg/i for BOD and 25 mg/I for TSS as 30 day averages and 50
mg/i for SOD arid 63 mg/i for TSS as daily maximums. During the
time period since the equipment failure in its West Final
S~ttiingTank occurred, the Petitioner’s discharge monitoring
reports to the Agency pertaining to SOD and suspended solids
levels have indicated the following SOD and TSS concentrations in
its effiuent~
Date
5/21/85
4
~.
3
52
116
5/22/85
3.7
30
27
5/23/85
3.8
43
34
5/24/85
3.6
124
194
5/25/85
3,2
123
74
5/26/85
2.9
215
276
5/27/85
.3.0
28
40
5/28/85
3.6
15
5
5/29/85
3.6
Ii
6
5/30/85
3.8
38
54
5/31/85
3.3
33
46
6/1/85
3.6
71
136
6/2/85
2.4
12
2
6/3/85
4.1
21
7
64-272
—3--
6/4/85
3.6
21
14
6/5/85
3.1
Not I~.vailab1e
7
6/6/85
3.9
Not Available
7
6/7/85
3.8
Not Available
9
6/8/85
3.4
Not Available
10
The Petitioner has emphasized that the failure of the drive
cage mechanism in its West Final Settling Tank was of an
emergency nature and totally unexpected. Therefore, the City
felt compelled by circumstances to expeditiously proceed with the
necessary repairs to the west ta~ik and return it to service as
soon as possible instead of doing nothing until the requisite
variance was granted. The Agency agrees that, because of the
emergency nature of the breakdown, the Petitioner acted properly
in limiting the potential environmental damage by making the
necessary repairs to the west settling tank as soon as
possible. (fec. 2).
The Agency believes that the environmental impact of
granting the proposed provisional variance will be minimal
because of the short duration of the requested variance and the
fact that treatment will be provided by the remaining treatment
units. The Agency has indicated that the City has presented an
appropriate plan for correcting the present environmental
problems and for preventing the same adverse situation from
occurring in the east settling tank, (Rec. 3), Both the City
and the Agency feel that the alternative (i.e.~ “to do nothing
and possibly have both final settling tanks out of service”)
would “result in a longer and more serious environmental
impact”. (fec. 3). Therefore, the Agency has concludel that the
City of Beividere ~has chosen the best alternative for correcting
the problem and preventing future reoccurrence”. (fec.
3i,
The Agency has noted that about 1—1/2 to 2 weeks of
favorable weather is necessary to properly drain and perform the
appropriate work on the East Final Settling Tank (including the
time necessary to peri~iitthe WWTP to regain its equilibrium).
Weather permitting, the City hopes to begin work on its East
Final Settling Tank during the week of June 17~i985~ (Rec, 3).
Accordingly, the Agency has concluded that compliance on a
short—term basis with the interim effluent limits for BOD and TSS
set forth in
the Petitioner’s NPDES Permit would impose an
arbitrary or unreasonable hardship upon the City of Belvidere,
Therefore, the
Agency recommends that the Board grant the
Petitioner a provisional variance for a
period of 30
days,
subject to certain conditions.,
Pursuant to Section 35(b) of the Illinois Environmental Act,
the Board hereby
grants the provisional variance as recommended.
64-273
This Opinion constitutes
the
Board1s
findings of fact and
conc1usion~ of law in this matter,
ORDER
The City of ~o1videre is hereby granted a provisional
variance from
the
interim effluent limits for SOD and TSS in its
NPDF,S
permit No.
IL
0027685, subject to the following conditions~
1. This provisional variance shall commence on the date of
the floard Ord~ ~nd continue for 30 days, or until one week after
th~ cast Final Sett1inc~
Tank is placed back in service, whichever
occurs first.
2.
During
the
provisional variance period, Petitioner shall
collect samples
and analyze them
for BOD and TSSO These results,
along with
the daily
fiow~- shall be recorded and submitted to Mr.
Robert Voss of the Agency~s Compliance Assurance Section within
10 days
of the
end of the
variance period at the following
address
Illinois Environmental Protection Agency
Division of Water Pollution Control
Comoliance Assurance Section
2200 Churchill fload
Springfield, Illinois 62706
3, The Petitioner
shall notify Mr. Robert Voss via
telephone at 217/782—9720 when the East Final Settling Tank is
removed from service and when it is returned to service. 3ach
telephone notification shal:1 be confirmed within 5 days with a
written notice Sent. to Mr. Robert Voss at the address given
above.
4. During the provisional variance period, the Petitioner
shall meet
&f1u~nt limits
of 80 mg/i for 30!) and 120 mg/i for
TSS.
5, Th~
Petitioner
;30a11 return the East
Final
Settling Tank
to
service
a~ quic:kiy
as ~os~ihie~ and
shall
provide
the best
treaf:ment
tic~hi’~durthq
th~provisional
variance
period.
6.
Within
10
days of
the date of the Board’s Order, the
petitio~iersh~l1 execute a C~rtificate
of AcceDtance
and
Agreement which stall
he
sent to Nr, Robert Voss of the Agency at
the address specii~ied in item #2 of this Order.
This certi.fication shall have
the following
form:
i~
(We)
_____________,having
read
the Order of the 1i.Linois Pollution Control Board
In
PCB 85—81
dated June 13,
i9~35, understand and accept
said Order, realizing
84-274
—5-.
that such acceptance renders all
binding and enforceable.
terms and ce~idition~thereto
Petitioner
By: Authorized
Agent
Date
IT
IS SC ORDERED,
I, Dorothy M. Gunn, Clerk of the Illinois Pollution Control
Board, hereby certify
that
the above Opinion and Order was
adopted on the /3~-’day of
_______~~,
1985 by a vote
of
~
11
Control Board
84-275