ILLINOIS POLLUTION CONTROL BOARD

February 21, 1980

SANITARY DISTRICT OF DECATUR,

Petitioner,

PCB 79~250

ENVIRONMENTAL PROTECTION AGENCY,

Respondent.

OPINION AND ORDER OF THE BOARD (by Mr. Dumelle):

Petitioner has requested a variance from Rule 203(f)

and Rule 404(f) of Chapter 3: Water Pollution. The Agency

has recommended that a variance be granted subject to

conditions. No hearing was held.

Petitioner~s plant is classified as a secondary

treatment plant. Treatment is accomplished by air and

oxygen activated sludge systems with an additional final

stage consisting of polishing lagoons. Plant effluent is

discharged to Stevens Creek just before the Creek joins with

the Sangamon River.

Major operational problems have been encountered by

Petitioner since 1975 when its secondary system was put into

full operation. Reasonably consistent operation of the

equipment was achieved in 1979,

Heavy industrial overloading of the main treatment

plant caused or contributed to operational odors and BOD

and suspended solid levels exceeded those levels containe

in Petitioner~s NPDES permit. A. B. Staley and the Archer-

Daniels~-Midland

Company,

two major tributary industries,

have proposed settlements at a January 21, 1980 hearing

(PCB77—157), The settlement is to be reviewed by the Board

and is to include comprehensive plans to reduce waste water

loadings to the sewage treatment plant. Industrial waste

discharges to~the sewage treatment plant have been reduced

and there have been no recent excessive discharges, Despite

these proposed comprehensive plans it appears doubtful that

Petitioner will consistently meet 10/12 mg/i BOD5 and

3

7—4

11

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—

suspended

solids effluent limitations for design flow as

required by NPDES Permit 1L0028321 unless significant

facility improvements

are

made under the construction grants

program.

The sewage treatment plant has a hyperchlorination

system

for

ammonia nitrogen

control.

However,

both

Petitioner and the Agency have stated that chlorine residual

and

chlorinated compounds from hyperchlorination

are

more

detrimental to the environment than current ammonia nitrogen

levels.

Acceptable facilities

are

to be a part of the

proposed wastewater treatment plant expansion program.

A Step 1 Facilities Plan was

submitted

to the Agency in

1976 after Petitioner received a Federal Grant. This Plan

has not been fully

approved

by the USEPA,

and prior

to Step

2 grants,

a further’ study of combined sewer ovêrf low,

engineering work

and

an

amendment

to Petitioner’s sludge

disposal plan must be undertaken. It is estimated that Step

2 funding will not be received for at least a year.

The Agency supports the variance from Rules 404(f) and

203(f) and 402 requirements for a

period

of five years or

until Petitioner’s, upgraded facilities are completed,

finding

that no detrimental environmental impact of human,

plant or animal life is anticipated. An undue economic

hardship would be placed on Petitioner should plant

expansion be required without benefit of federal grant

assistance. The total cost of plant expansion is estimated

at $31,045,000. Federal grant assistance would amount to

$23,284,000.

The effluent quality problems appear to be partly

caused by polishing lagoons which have been allowed to

become too full. The ponds are 8 ft. deep and 4 ft.

accumulations of sludge are

now

present. Thus, to a large

extent,, the, effluent deterioration is self imposed.

However, because of the problems in getting the UNOX system

to operate correctly, the Board will grant the variance

requested for

HOD5 and suspended solids.

The statements in the record as to the environmental

effects of chlorine residuals and chloramines upon

‘

aquatic

biota

are

conclusory. The Board will deny this

portion of

the variance petition without prejudice to. a

further

proceeding in which the alleged ill effects can be better

This Opinion constitutes the Board’s findings of fact

37—412

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“3—

ORDER

A. It is the Order of the Pollution Control Board that

Petitioner’s petition for variance from Rule 404(f) of

Chapterand

12 mg/i

3

as

suspendedregards

effluentsolids

helimitationsgranted subjectof

10 mg/lto

theBOD5

following conditions:

1, Concentrations of 20 mg/l BOD5 and 20 mg/i

suspended solids on a 30 day average shall

be met in the effluent.

2.

The best operation and maintenance

practices shall be followed at the sewage

treatment plant so as to minimize the discharge

of BOD5 and suspended solids.

3, The variance shall expire five years from the

date of this Order or when construction is

completed.

4, The Petitioner shall diligently pursue grant

funding and meet all grant-related schedules.

5. Within 45 days of the date of this Order, the

Petitioner shall execute and forward to the

Illinois Environmental Protection Agency,

2200 Churchill Road, Springfield, Illinois,

62706, a Certificate of Acceptance and

Agreement to be bound to all terms and

conditions of this variance. This 45-day

period shall be held in abeyance if this

matter is appealed. The form of the

Certificate shall be as follows:

CERTIF ICATION

I, (We), __________________________, having read and

fully understanding the Order in PCB79-250, hereby accept

that Otder and agree to be bound by all of its terms and

conditions.

SIGNED

TITLE

DATE

37—413

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~~‘2~~

B. The Agency is hereby ordered to amend the

District~s NPDES Permit, IL0028321 to be

consistent with the above variance.

C. The request for variance from ammonia limits in

the effluent is denied without prejudice to a

later proceeding.

IT IS SO ORDERED.

I, Christan L. Moffett, Clerk of the Illinois Pollution

Control Board, hereby certify4 that the ~o e Opinion and

Order were adopted on the

~I

~ day of ~

,

1980 by a vote of

T~o

Christan L. M~Wtt, Clerk

Illinois Pollution Control Board

37—414