ILLINOIS POLLUTION CONTROL BOARD
June 5, 1986
CITY
OF
DIXON,
)
Petitioner,
v.
)
PCB 85—217
ILLINOIS ENVIRONMENTAL
)
PROTECTION AGENCY,
)
Respondent.
)
OPINION AND ORDER OF THE BOARD
(by 3.
Anderson):
This docket was initiated upon the December 30,
1985 filing
of what was captioned as
a joint petition
by the City of Dixon
(City)
and the Illinois Environmental Protection Agency
(Agency)
seeking
an extension to
the December 31,
1985 deadline contained
in 35
Ill. Adm.
Code 306.373
for the filing of petitions for
exceptions to
the combined
sewer overflow
(CSO)
regulations.
In
summary,
the City asserted that
it had made every effort to
comply with the date specified in 35
Ill. Adm. Code 306.373 but
for reasons beyond
its control,
was unable
to comply with said
date: that because
of unusually dry weather
and
a lack of
significant
rain events,
the Petitioner was unable
to monitor any
first
flush events
to determine the level
of compliance currently
being achieved
at the City~scombined sewer
overflows.
Further,
the City stated that it believes that existing combined
sewer
overflows have
a minimal impact on Rock River water quality and
do not restrict stream
use,
such that sewer separation projects,
costing $2,348,000
to build, would produce little benefit, but
that the City does not have sufficient documentation at present
to
come
before
the
Pollution
Control
Board
with
a
Petition
for
CSO Exception.
By Order
of January
9,
1986,
the Board determined
that as
a
matter of procedure this request would
be more appropriately
handled
as a petition
for variance from Section 306.373.
The
City filed
a variance petition with the Board on February
4,
1986
but the petition was not served upon the Agency until March
24.
By Order
of April
10,
the Board
noted that to protect the rights
of
the
public
to
timely
file
objections
and
the
Agency
to
timely
file
either
an
objection
or
a
Recommendation
pursuant
to Section
37(a)
of
the
Environmental
Protection
Act,
that
the
statutory
time
periods
must
be
computed
from
March
24.
No
objections
were
filed, and
as hearing was waived by the City,
none has been
held.
On
April
28,
the
Agency
filed
a
Recommendation
in
support
of
grant
of
variance,
subject
to
conditions.
Decision
in
this
70-108
—2—
matter
is being expedited consistent with the Board’s
observations
in
its April
10 Order.
The City of Dixon, which
is located
in Lee County, owns and
operates
a Municipal Wastewater Treatment Facility which serves
the Dixon community consisting
of approximately 18,147
residents
and numerous commercial and
industrial establishments.
The
treatment plant
is located on
the bank of the Rock River, into
which discharge occurs.
Facilities include raw sewage pumps,
communitors,, grit removal, primary sedimentation, aeration
tanks,
final sedimentation, disinfection
(chlorination),
anaerobic digestion, sludge storage, drying
beds, and assorted
appurtenant facilities.
The plant has
a design average flow of
3.4 million gallons per day
(mgd)
and
a design maximum flow of
8.4 mgd.
Pursuant to
a variance granted
in PCB 85—47
(August
15,
1985),
expiring
in October,
1986,
the plant’s Outfall 001
is
operating under interim effluent limitations
for BOD and TSS
(respectively 30/40 on monthly averages and 45/60
on daily
average).
Variance was granted
in conjunction with the City’s
upgrading of
its dry weather
sewage treatment facilities.
The
improvements consist of the construction of
an additional
clarifier and larger aerators.
The Agency reports that these
improvements are currently under construction with the larger
aerators being
installed in September,
1985,
and the
additional
clarifier now scheduled
for completion
in late June
or early
July,
1986.
Other minor work
is also being completed.
The collection system tributary to
the City’s plant covers
about
2,250 acres, according
to Petitioner’s Municipal Compliance
Plan
(MCP).
Of that 2,250 acres, about
1,900 acres are served
by
separate sanitary sewers
and the remaining 350 acres are served
by combined sewers.
The combined sewered area, then,
is about
15
of the service area
in the City.
Since the interceptors were
constructed when the majority of the service area was combined,
a
great deal of storm flow has been removed.
Sewer separation
for
the remaining portion of the service area
is expected
to be
accomplished as street improvements are made, but since the areas
are primarily residential
it is unlikely to be done anytime
in
the near future.
The combined sewered areas generally lie along
and adjacent to
the interceptor sewers and overflows.
The City retained a consulting engineer
in December 1984
to
prepare
a Combined Sewer Overflow Exception study
in accordance
with Agency guidelines.
The engineers, with cooperation of City
Sewage Plant personnel, set up
a program to monitor major
combined sewer overflows for first
flush determinations during
wet weather bypassing to the Rock River.
Concurrently, the
engineers completed Phase
1
—
Background Information
(Exhibit 1)
and Phase
II
—
Preliminary Stream Inspection (Exhibit 3), with
the latter report documenting the stream characteristics
(i.e.
—
high flow volumes, reaeration capacity, excellent water quality,
productive sport fishery)
and the lack of any evidence of
70-109
—3—
pollution
(i.e.
—
no sludge deposits or other
evidence of
pollution were noted
in the survey).
In the Spring of 1985 the City also initiated
a major
cleaning program for
the interceptor sewers,
the only such effort
made
in about
20 years.
This involved removal
of grit deposits
in the range of one—half
to two—thirds of the pipe diameter;
the
deposits were not previously known
to be
so substantial.
The City asserts that unusual conditions were encountered
during the CSO monitoring
period, such as there being one of the
driest late spring,
summer, and early fall periods
in many years
and the lack of any heavy,
intense
rainfall events.
As
a result
of these weather conditions as well as the restoration of lost
interceptor
sewer capacity by cleaning, no overflows occurred,
from the middle of
May through the middle
of October, at the
CSO’s that previously were activated for
over 90
of all rain
events.
The interceptors conveyed all flows
to the treatment
plant, with the exception
of one overflow for one event.
This
event was not representative of
a realistic first
flush (Exhibit
6).
Therefore,
no determination could
be made as
to impacts on
the Rock River
or the level
of compliance with Section 306.305.
It
is the City’s opinion that first
flush and
a significant
part of the next ten
times dry weather
flows
(lOx flows)
from the
combined sewered areas are probably being conveyed
to the
treatment plant by the clean interceptor sewers, but no
documentation
is available
for presentation to
the Board with
an
Exception Petition since studies to date were designed
to monitor
significant overflow events.
The City believes that the cleaning
of the
interceptor sewers changed conditions so drastically that
old studies, including the facilities plan overflow monitoring,
are no longer applicable.
Accordingly, during
the next year,
the City proposes
to
monitor the overflows
to determine which are still
active, as
well
as to determine what percentage of first
flush and lOx
flows,
for each active overflow,
are presently being conveyed
to
the
treatment plant during
precipitation events.
The City
believes the
information developed
in these further studies will
allow the City and Agency to come before
the Board with
an
adequately documented Petition for Exception to the Combined
Sewer
Overflow regulations
if indeed compliance with Section
306.305
is not being achieved.
The City also asserts that denial
of variance to allow it to
complete CSO monitoring will impose an arbitrary economic
hardship.
The City
is
in the EPA grant program having completed
the Step
I Facilities Plan
in 1982.
The Plan concluded that
separation of the remaining
15
of the
service area was the least
costly full compliance alternative.
However,
the City’s priority
ranking
is
so poor that it has no expectations of
receiving any
grant funding, with the result that all improvements required
must be paid out of local
funding.
The City alleges that the
70-110
—4—
estimated $2,348,000
cost of
a major separation project would be
burdensome
on
a City already faced with
a difficult economic
situation,
given
the
other upgrading required
for the City’s
treatment plant
and sewer system.
The City’s costs
for the
aforementioned plant upgrading project are $630,000, of which
$355,000 are
financed from local
funds and revenue bonds,
and
$275,000 from
a non—USEPA grant.
The City has also committed
to
complete sewerage works improvements by July,
1988,
which include
provision of standby power
at the treatment plant, elimination of
river intrusion during flood stages at certain overflows, and
installation of waterlight lids on manholes
in the
floodplain.
The City has not provided details on the financing of this
$246,000 project..
The Agency does not disagree with the City’s various
assertions.
The Agency notes that there does not seem to be
a
significant impact on the Rock River
by the City’s CSO
discharges,
and states
its belief that maintenance of the status
quo
for
the variance period will have little impact on the river.
The Board
finds that denial of variance would
impose
an
arbitrary or
unreasonable hardship, given
that the City’s sewer
cleaning program has resulted
in conveyance
of considerably more
flows
to the plant, making prior CSO data obsolete, and
that
weather conditions have prevented accurate monitoring of what CSO
discharges have occurred
since
the sewers were flushed.
Variance
is therefore granted until June
1, 1987 with conditions similar
to those suggested
by the Agency.
The Board will,
of course,
entertain
a petition
for extension of this variance
in the event
that weather conditions during
the next year do not allow the
City to amass sufficient data
to make reasonably informed CSO
compliance determinations.
Finally,
the Board notes that the utility of sewer
cleaning
in achieving CSO compliance was the subject of much discussion
in
the R8l—17 hearings which lead
to creation of the CSO exception
procedure.
The Board views the results of the City’s one—time
cleaning project with interest, and encourages the City to
consider
the benefits of
a regular
interceptor sewer cleaning
program in development of any CSO strategy.
This Opinion constitutes the Board’s findings of fact and
conclusions of law
in this matter.
ORDER
1)
The City of Dixon
is hereby granted variance until June
1, 1987 from
the December
31, 1985 deadline of
35
Ill.
Adm. Code
306.373 for
the
filing of
a petition for exception to
the
combined sewer overflow
(CSO)
regulations pursuant
to 35
Ill.
Adm. Code 306.350—306.374,
subject to the following conditions:
a)
The City shall commence and complete CSO monitoring
as expeditiously as
is practicable.
70-111
—5—
b)
On or before February
1,
1987,
the City shall
notify
the Agency
in writing of the results of
its
monitoring.
This notification shall
include any
determination made by the City as
to
a)
its
intent
to file
a petition for variance extension,
b)
its
intent to file
a CSO exception petition, or
c)
its
lack of need for either
due
to achievement of CSO
compliance.
This notification shall
be sent to
James
Frost, c/o Compliance Assurance Section,
Division of Water Pollution Control, 2200 Churchill
Road, Springfield, Illinois
62706.
c)
The City shall continue
to pursue the upgrading of
its treatment plant and sewerage system through the
construction grants program and shall continue
to
take all reasonable measures
to
insure that the
maximum flows practicable are conveyed
to its
treatment plant.
2)
Within 45 days of the date of
this Order,
the City shall
execute and submit
to the Agency at the address listed
in
paragraph 1(b),
above,
a Certificate of Acceptance
and Agreement
to be bound
to all terms and conditions of
this variance.
This
forty—five day period
shall
be held
in abeyance
for any period
this matter
is being appealed.
I,
(We),
____________________________,
having
read
the
Order
of the Illinois Pollution Control Board,
in PCB 85—217,
dated June
5,
1986,
understanding and accept
the said Order,
realizing that such acceptance renders all terms
and conditions
thereto binding and enforceable.
Petitioner
By:
Authorized Agent
Title
Date
IT
IS SO ORDERED.
70-112
—6—
I,
Dorothy
M. Gunn, Clerk of the Illinois Pollution Control
Board,
hereby certify that the
bove Opinion and Order was
adopted
on
the
~
day of
—,
1986,
by
a
vote of
7~~)
.
/~—
II
~2
~
Dorothy
M.
Ginn,
Clerk
Illinois Pollution Control
Board
70-i
j~