THOMAS D. MARCUCCI
MAYOR
JANET S.
EDGLEY
CITY CLERK
DAVID J. DYER
CITY TREASURER
THOMAS P. BORCHERT
CITY MANAGER
February 28,
2002
STATE
OF IWNOIS
Illinois
Pollution
Control Board
Pollution Control Board
Attn: Dorothy Gunn, Clerk
James R. Thompson Center
100 West Randolph Street
Suite 11-500
-
Chicago, Illinois 60601
Re: R002 —11 (Rule making — Water)
The City of Elmhurst would like to stand on record as supporting the proposed
amendment to 351L Admin. Code 304.120 to be modified by adding paragraph
“g”, which specifies that compliance with the 5 day biochemical oxygen demand
(BOlD5) numerical standards be determined by analysis of a 5 day carbonaceous
biochemical oxygen demand (CB0D5).
In the mid 19801$ the wastewater industry in Illinois had a very lively discussion
of the efficacy of the BOlD5 versus CBOD5 The original 5-day BOO test was not
intended at the time of its initial used to be a measurement of the nitrogenous
component of wastewater. Also at the time few if any PO1Ws were achieving
any significant conversion of ammonia to nitrite-nitrate. It was argued that (and
considered safe to assume) that the database of BOO5tests contained only
carbonaceous oxygen demanding data. The results of the 198CYs discussion
resolved that the quality of the data and the comparison value of the data
(comparing past to present) could be maintained by limiting the oxygen demand
test to the carbonaceous component Only With the installation of advanced
activated sludge processes the BOO5test accuracy became suspect due to the
introduction of nitrogenous BOD Furthermore, the measurement of the
nitrogenous BOD in the BODE exam is uncontrolled and interferes with the
original BOO test There is no way to differentiate what component of the sample
was responsible for the oxygen consumption, the carbonaceous or nitrogenous
components.
Measurement of BOD is an important parameter for wastewater plant staff to
gauge the efficiency of their process operations. The CBOD5 measures simply
the carbonaceous component of the oxygen demanding effluent. There are
separate tests available for measuring nitrate-nitrite and the ammonia
CITY
209
ELMHURST, ILLINOIS 60126-2755
(630) 530-3000
FAX (630)
530-3014
www. eimhurs
t.
org
RECEIVED
CLERK’S OFFTCE
MAR 5 - 2002
components of the effluent. It makes great sense to measure the individual
components of the effluent separately to have accurate test results for each of
these components. The BOO5 will measure both constituents of that oxygen-
demanding component of the effluent without accurately quantifying either in any
detail. For that reason the City of Elmhurst supports the Illinois EPA effort to
maintain the CBOD5 as a measurement of oxygen demanding carbonaceous
material as a separate test from measurement of nitrate-nitrite and ammonia.
Acceptance of the CBOD5 as a measurement of the efficiency of any P01W will
not relax any existing discharge standards.
By formally recognizing the use the CBOD5 for measuring oxygen consuming
wastes under section 304.120 the board will be unifying the regulations with the
generally accepted theories in municipal wastewater treatment.
Sincerely,
Dennis Streicher
Director of Water& Wastewater
Cc
Thomas P. Borchert, City Manager
Harlan Spiroff, City Attorney
