GLENBARD

WASTEWATER AUTHORITY

21 W. 551 Bernis Road

Glen Ellyn, Illinois 60137

(630) 790-1901 • Fax: (630) 858-8119

February 28, 2002

Illinois Pollution Control Board

Attn Dorothy Gunn, Clerk, Re Docket R02-1 1

James R Thompson Center 100 West Randolph Street

Suite 11-500

Chicago, IL 60601

Dear Ms. Gunn:

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5

2002

STATE

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Pollutj0,,

Cont,01 Board

On behalfofthe Glenbard Wastewater Authority, I would like to offer the following

comments in support ofthe proposed amendment to 35 III Adm Code 304 120 intended to

clarify the confusion concerning the existing BOD term in the regulations

The purpose ofsecondary treatment for wastewater treatment plants is to remove suspended

solids and biodegradable matter (carbonaceous material~from-~astewaterto a specified level of

quality The USEPA originally required that the secondary treatment process efficiency be

measured in total BOD (BOD5) but subsequently, during 1984, authorized the use of

carbonaceous BOD (CBOD) for determination ofthat efficiency This authorization was largely

predicated upon the fact that the interference ofnitrogenous oxygen demand (NOD) interfered

with the universal application ofthe BOD5 test as a comparative measure of secondarytreatment

process efficiency Depending on a variety ofcircumstances regardingthe wastewatersample and

treatment plant operations, this interference can result in BOD5 test results that do not accurately

reflect the true efficiency ofthe secondary treatment process This revelation led to the

development ofthe 5-day carbonaceous biochemical oxygen demand (CBOD5) test, a procedure

which allows the oxygen demand due to carbonaceous material to be separated from the oxygen

demand resulting from ammonia-nitrogen

The IEPA began including CBOD as the effluent limit in NPDES permits since the EPA’s

authorization ofthe same measure during 1984 and has continued that practice ever since The

referenced issue before the Board is not intended to extend relief to dischargers from the

standpoint ofa relaxed discharge standard Clearly, the purpose is to eliminate the ambiguity

testassociatedfor measuringwith

thedeoxygenatingexisting regulationwastes,terminologythe

Board

Bywillformallymerely

berecognizingacknowledginguse

ofthethegenerallyCBOD5

accepted theories and practices in our industry for assessing the removal oforganic matter in the

secondary treatment practice

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7

William E. Kuzia, P

Utilities Manager