ILLINOIS POLLUTION CONTROL BOARD
June 23,
1992
IN THE MATTER
OF:
)
PETITION OF THE DECATUR
SANITARY
)
AS 91-7
DISTRICT FOR ADJUSTED STANDARD
)
(Adjusted Standard)
FROM 35 ILL.
ADM. CODE 306.305(b)
)
OPINION
AND
ORDER OF THE BOARD
(by G.
T.
Girard):
On August 22,
1991,
the Decatur Sanitary District (District)
filed
a petition for an adjusted standard with the Board.
The
District is seeking an adjustment to the combined sewer overflow
(CSO)
disinfection requirement of 35 Ill.
Adm. Code 306.305(b).
On February 21,
1992, the Illinois Environmental Protection
Agency
(Agency)
filed its response recommending that the adjusted
standard be granted with certain conditions.
No hearing was held
in this proceeding
(~
Petition of Decatur Sanitary District for
adlusted standard from 35 Ill. Adm. Code 306.305(b), April 23,
1992)
and the Board has received no comments from the public on
this petition.
BACKGROUND
The District,
located in Macon County,
acts as the regional
wastewater treatment authority for the City of Decatur and the
Villages of Forsyth and Mt.
Zion.
The wastewater treatment
plant,
owned and operated by the District, employs 70 full time
employees and serves approximately 100,000 residents and
industrial and commercial users.
(Pet. at 1.)’
Approximately 31
million gallons per day are processed at the treatment plant and
then discharged into the Sangamon River just upstream from the
confluence with Stevens Creek.
The treatment process has a
design average flow of 41.0 million gallons per day and includes
preliminary and primary treatment followed by a two—stage
activated sludge biological treatment process with effluent
disinfection by chlorination.
(Pet.
at 2).
Treated sludge is
ultimately disposed of by land application on area farms.
The
expansion and upgrading of the main treatment plant was completed
in the spring of 1990 at a construction cost of $74,221,650.
(Pet.
at 2.)
The District also owns and operates two combined sewer
overflow treatment facilities
(CSO treatment facilities)
and has
two others under construction to be completed in the spring of
1992.
These four CSO treatment facilities were built by the
District pursuant to a consent depree entered in the U.S.
District Court.
(Pet.
at 7.)
The four CSO treatment facilities
The Petition is cited as “Pet. at
“
and the Agency Response
will be cited as “Res.
at
“.
134—379
2
will provide for the capture of first-flush—flows and will
provide the equivalent of primary treatment for flows
in excess
of the first flush.
The four CSO treatment facilities do not
have provisions for the disinfection of post—first flush flows;
therefore the District is seeking an adjusted standard for these
four CSO treatment facilities.
The combined cost of the
construction of the four CSO treatment facilities was
$16,042,000.
(Pet. at 2.)
DISCUSSION
Section 28.1(a)
of the Illinois Environmental Protection Act
(the Act) provides that after adopting a regulation of general
applicability, the Board may grant an adjusted standard for
persons who can justify such an adjustment.
Section 28.1(b)
provides that the Board may specify a level of justification
required of a petitioner for an adjusted standard.
Although the
Board’s regulations at 35 Ill.
Adm. code 306 do not contain a
level of “justification” for an adjusted standard, the Board has
held that the substantive requirements of
35 Ill. Adm. Code
306.Subpart D are to be used for justification of an adjusted
standard from the regulations at 35
Ill.
Adin.
Code 305.
(Petition of the City of Jacksonville for Adiusted Standard From
35
Ill.
Adn*.
Code 306.305(b), AS 90—1,
August 9,
1990;
and City
of Ocilesby
v.
Illinois Environmental Protection Agency, PCB 86-3,
February 6,
1992).
Therefore Section 28.1(b)
of the Act applies
to the District’s petition for adjusted standard.
The District proposes that the Board adopt the following
adjusted standard for its CSO discharges:
The Sanitary District of Decatur is granted
an adjustment to the disinfection
requirements of 35 Ill. Admin.
Code
306.305(b).
This adjustment allows the
Sanitary District of Decatur to discharge
combined sewer overflows in excess of the
first flush without disinfecting such flows.
Pet. at
9.
The Agency, which recommends granting the adjusted standard,
suggests that the language proposed by the District be amended to
include the specific sites of the four CSO treatment facilities.
Justification
The District asserts that to achieve compliance with the
existing regulation,
the District would need to add disinfection
equipment to the newly constructed CSO treatment facilities.
The District indicated that the annualized capital cost is
$1,829,939 and the annual operation and maintenance cost is
I 34—380
3
$304,070.
(Pet.
at 8.)
The increase in annual cost would result
in an additional cost to the average residential user of
approximately $13.84 per year.
(Pet. at 9.)
These costs are in
addition to the $16,042,000 already spent by the District to
construct the CsO treatment facilities.
Therefore,
the District
maintains that a chlorination disinfection system is “technically
infeasible to operate and will substantially increase annual
capital, operational and maintenance costs”.
(Pet.
at 9.)
The District maintains that chlorination is technically
infeasible because of the difficulty of establishing proper
chlorine dosages due to the variations in the CSO flow rate,
solid concentrations and relative short duration in post—first—
flush flow.
The District states that:
The inability to establish a proper chlorine
dosage could result in either a chlorine
level so low that the fecal limit would be
exceeded; or so high that excess chlorine
concentrations would be released to the
stream causing a negative impact on the
stream biota.
(Pet. at 11.)
The District further maintains that the receiving stream,
the Sangamon River,
is not used as a public water supply within
100 miles of the District.
The fecal coliforiu levels in the
river will be reduced downstream with the completion of the CSO
treatment facilities.
However, the District maintains that
releases from Lake Decatur during wet weather are more likely to
be the cause of increased fecal coliform levels than the
District’s being granted the requested relief.
The District
further maintains that the four new CSO treatment facilities will
provide some reduction of the fecal coliform levels downstream.
(Pet at 9.)
The District states that the reduction is “due to
the capture and complete treatment and disinfection of dry
weather and first-flush—flows, that is equivalent to the primary
treatment to flows in excess of the first flush”.
(Pet.
at 9.)
With the completion of the four CSO treatment facilities,
the District maintains that it “will reduce the number of
overflow events from 94 to 35 annually”.
(Pet at 11.)
The
District states that prior to the implementation of the CSO
program there were 690.7 million gallons of overflow per year.
Upon completion of the CSO program, 39.9 million gallons annually
will be captured in first flush tanks and returned to the sewer
system for complete treatment.
I~addition,
an estimated 650.8
million gallons will receive the equivalent of primary treatment
prior to discharge into rivers.
(Pet. at 11.)
agency Response
I 34—38
I
4
The Agency states that it “generally supports the District’s
petition for adjusted standard”.
(Res.
at 7.)
The Agency agrees
that there are “difficulties in establishing and maintaining the
proper chlorine dosage while ensuring an adequate reduction in
fecal coliform levels and preventing high chlorine residuals”.
(Res.
at 4.)
The Agency further agrees that the CSO treatment
facilities will reduce the fecal coliform levels in the receiving
stream and thus the environmental impact of the adjusted standard
is not significant.
(Res.
at 5.)
The Agency disagrees with the District’s statement that
fecal coliform water quality violations typically occur in Lake
Decatur.
(Res. at 5.)
The Agency also questions the District
assertion that there is little or no human contact with the
receiving stream.
The Agency stated that it is:
concerned generally with human health risks
associated with disinfection exemptions,
and
will not generally grant disinfection
exemptions pursuant to 35 Il.
Adm. Code
304.121 for sewage treatment plant discharges
in residential areas unless there is some
kind of barrier precluding access to the
stream.
(Res.
at 6.)
The Agency’s concern with public safety is well taken.
However, as noted in the Board’s April 23,
1992 order, no member
of the public has presented comments to the Board on this matter.
Further,
other than expressing the concern about public safety
and noting the proximity to residential areas of two of the CSO
treatment facilities, the Agency has not presented any facts
which persuade the Board that the granting of the adjusted
standard would be a threat to public safety.
CONCLUSION
The Board finds that the District has demonstrated that
meeting the provisions of the 35
Ill. Adm. Code 306, the rule of
general applicability,
is not technically feasible nor
economically reasonable.
Further, the District has demonstrated
that an adjusted standard which excepts the combined sewer
overflow from treatment will not have an adverse environmental
effect.
The Agency’s response indicates that an adjusted
standard is warranted.
Therefore, the Board grants the District
the following adjusted standard from 35
Ill. Adm. Code 306:
The Sanitary District o~Decatur is granted
an adjustment to the disinfection
requirements of 35
Ill. Adm. Code 306.305(b)
for its discharges from the McKinley Avenue,
Lincoln Park,
7th Ward, and South Oakland CSO
treatment facilities.
This adjustment allows
134—3 82
5
the Sanitary District of Decatur to discharge
combined sewer overflows from these
facilities
in excess of the first flush
without disinfecting such flows.
This opinion constitutes the Board’s findings of fact and
conclusions of law in this matter.
ORDER
Pursuant to Section 28.1(b), the Board hereby grants an
adjusted standard from 35 Ill.
Adm. Code 306.305(b) to the
Decatur Sanitary District.
The following standard becomes
effective on the date of this order:
The Sanitary District of Decatur is granted
an adjustment to the disinfection
requirements of 35 Ill. Adm. Code 306.305(b)
for its discharges from the McKinley Avenue,
Lincoln Park,
7th Ward,
and South Oakland CSO
treatment facilities.
This adjustment allows
the Sanitary District of Decatur to discharge
combined sewer overflows from these
facilities in excess of the first flush
without disinfecting such flows.
IT IS SO ORDERED.
Section 41 of the Environmental Protection Act
(Ill.Rev.Stat.
1991,
ch.
111 1/2, par.
1041) provides for the
appeal of final orders of the Board within 35 days.
The Rules of
the Supreme Court of Illinois establish filing requirements.
I, Dorothy M. Gunn, Clerk of the Illinois Pollution Control
Board, do hereby certify that the abov~opinion and order was
adopted on the
~?3•-’-~
day of
()-i~-~c4~~
,
1992, by a
vote of
7—o
.
7
Dorothy M. .4inn,
Clerk
Illinois P~yilutionControl Board
134—383