R
ECCEIVtED
FEB 1 4 2006
ILLINOIS ENVIRONMENTAL PROTECTIONAGENQTA
IlUtIon
TE
Control
ILLINOIS
February 10, 2006
City of Morrison
)
Petitioner,
)
v .
)
IEPA- 06-
'W
(Provisional Variance-Water)
ILLINOIS ENVIRONMENTAL
)
PROCTECTION AGENCY,
)
Respondent .
)
Re: Provisional Variance From Limits on Daily Maximum
For Ammonia Nitrogen of NPDES IL 0027006
Dear Mr. Osborn :
The Illinois Environmental Protection Agency (Agency) has completed review of the attached
provisional variance requests submitted by the City of Morrison (City) on February 3, 2006 and
February 8, 2006 . The City is in the process of making necessary repairs to its wastewater
treatment plant to correct a mechanical failure on one its trickling filters .
Background
The City of Morrison owns and operates a wastewater treatment facility located at 101 Andy
Brands Drive in Morrison, Illinois .
This treatment facility consists of a trickling filter plant
designed to treat an average design flow of 0.941 million gallons per day (MGD) and with a
2.586 MGD design maximum flow . Treatment consists of screening, shredding, grit removal,
influent flow measurement, primary settling, trickling filters, secondary settling, disinfection,
dechlorination, effluent flow measurement, anaerobic digestion, and aerobic digestion . The
facility discharges into Rock Creek . The 7Q10 of Rock Creek is approximately 14 .0 cubic feet
per second .
One of the two trickling filters at the wastewater treatment facility currently is in disrepair to a
point that it can no longer rotate . The trickling filter must be taken out of service and the rotary
distributor must be disassembled to replace all worn parts. The City estimates it will take
approximately two to three weeks for the repairs . The City is requesting a provisional variance
for 45 days to allow the nitrifying bacteria the necessary time for regrowth
.
Relief Requested
The City requests a variance from the ammonia nitrogen limitations contained in NPDES permit
IL 0027006 ( Attachment B). This permit requires the City to meet the following for ammonia
nitrogen :
During the period of the requested provisional variance the City will not exceed 18 mg/l
ammonia nitrogen as a daily maximum .
Agency Determinations
The Agency has reviewed the requested provisional variance and has concluded the following
:
1. The environmental impact from the requested relief is predicted to be minimal ;
2. No other reasonable alternative appears available
;
3
.
No public water supplies, will be affected ;
4. No federal regulations will preclude the granting of this request ; and
5. The City will face an arbitrary and unreasonable hardship if the request is not granted
.
The Agency hereby GRANTS the City of Morrison a provisional variance from the ammonia
nitrogen limits of NPDES IL 0027006, subject to the following conditions
:
A. The provisional variance shall begin the day the trickling filter is taken out of
service for repairs and shall continue for a maximum of 45 days
.
B. The City shall operate its wastewater treatment system to produce the best effluent
possible, and at no time shall the City exceed a daily maximum of 18 mg/I for
ammonia nitrogen
.
Month
Monthly Avg. (mg/1)
Daily Max. (mg/1)
Apr-Oct .
4.2
5 .7
Nov-March
6.9
8.6
C. Immediate notification to the Agency shall be required if the 18 mg/I ammonia
nitrogen limit is exceeded and measures will be immediately taken to provide
supplemental treatment
.
D. The City shall notify Roger Callaway of the Agency by telephone at 217/782-9720
when the trickling filter is taken out of service for repairs and again when the
trickling filter is returned back to service . Written confirmation of each notice shall
be sent within five days to the following address :
Illinois Environmental Protection Agency
Bureau of Water - Water Pollution Control
Attention: Roger Callaway
1021 North Grand Avenue East, MC #19
Springfield, Illinois 62794-9276
E. The City shall sign a Certificate of Acceptance of this provisional variance and
forward that certificate to Roger Callaway at the address indicated above within one
day of the date of this order. The certificate should take the following form
:
I (We)
, hereby accept and agree to be bound by all
terms and condition of the provisional variance granted by the Agency in
dated
Petitioner
Authorized Agent
Title
Date
The City shall continue to monitor and maintain compliance with all other parameters and
conditions specified in its NPDES Permit No. IL0027006 .
Conclusion
The Agency grants this provisional variance in accordance with its authority contained in
Sections 35(b), 36(c), and 37(b) of the Environmental Protection Act (415 ILCS 5/35(b), 36(c),
and 37(b) (2004). The decision to grant this provisional variance is not intended to address
compliance with any other applicable laws or regulations
.
Robert A. Messina
Chief Legal Counsel
cc: Marcia Willhite
Roger Callaway
Tom Andryk
Vera Herst
