ILLINOIS POLLUTION CONTROL BOARD

April 3, 1980

CENTRAL ILLINOIS PUBLIC SERVICE COMPANY,

(Meredosia Power Station)

Petitioner,

v.

)

PCB 80-25

ENVIRONMENTAL PROTECTION AGENCY,

Respondent.

OPINION AND ORDER OF THE BOARD (by Dr. Satchell):

This matter comes before the Board upon a variance petition

filed February 1, 1980 by Central Illinois Public Service Company

(CIPS). The petition re~uest~~~for the Meredosia power station a

variance from the effluent standards for copper (total)

,

iron

(total) and iron (dissolved) of Rule 408(a) of Chapter 3: Water

Pollution for discharges of boiler and air heater rinse water

into the ash pond. The petition also requests a variance from

the Rule 408(a) effluent standard for total suspended solids (TSS)

for cooling tower blowdown and cooling tower emergency overflow.

On March 3, 1980 the Environmental Protection Agency (Agency) re-

commended that the variance he granted with conditions. No hearing

was held and no public comment has been received. Many of the facts

in this case are similar to those in PCB 80-16. The

~

Opinion

of this date in that case is incorporated by reference.

The Meredosia power station is a 588 megawatt fossil fueled

electric power plant which is situated in Morgan County. Boilers

5 and 6 are scheduled for cleaning during Intervals from February

24 through September 13, 1980. Boiler 5 will require about 35,000

gallons (133,000 1) of EDTA solution and Boiler 6 about 36,000

gallons (137,000 1)

.

Around 105,000 gallons (397,000 1) of rinse

water will be required for each. CIPS estimates that 1500 pounds

(675 kg) of iron and 300 to 500 pounds (135 to 225 kg) of copper

will be removed from each boiler (Pet. 3). The Agency estimates

that approximately 2000 pounds (900 kg) of iron and 200 pounds

(90 kg) of copper will be removed from each boiler (Rec, 3).

Under the requested variance boiler cleaning and air heater

rinse waters will be discharged into an ash pond which discharges

to the Illinois River. On October 23, 1979 the Agency issued to

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—2—

CIPS NPDES Permit IL 0000116 for the Meredosia power station.

CIPS’ appeal of permit conditions is before the Board in PCB 79-

248.

The Board finds that requiring immediate pretreatment of

rinse waters would impose an arbitrary and unreasonable hardship

on CIPS for reasons similar to those outlined in the Board~sOpinion

of this date in PCB 80-16. The variance will be granted with con-

ditions.

CIPS also requests a variance for the 15 mg/i effluent stan-

dard for TSS contained In Rule 408(a) of Chapter 3. The variance

is requested only for cooling water blowdown and emergency overflow

discharges to the Illinois River from Unit No. 4. CIPS has three

coal-fIred units which draw cooling water from and discharge di-

rectly to the river. These are not involved in the TSS variance.

Unit No. 4 is an oil-fired boiler which has a closed-loop system

utilizing a cooling tower. The TSS concentration would increase

in a no—discharge system as a result of evaporation in the tower.

To avoid this about ten percent of the cooling water is discharged

and replaced with fresh river water on each cycle through the

cooling system. Emergency overflows of the same water also occur.

Together these will be referred to as “blowdown.”

In PCB 79-248 CIPs seeks a finding that the TSS in the blow—

down is background drawn from the river and subject to the excep-

tion of Rule 401(b) of Chapter 3. CIPS has little data on this

discharge since the previous NPDES permit did not require its mon-

itoring and since the oil—fired unit Is seldom operated (Pet. 4, 8).

It has a predicted blowdown rate of 1787 gallons per minute (gpm)

(7000 1/mm) and a maximum of 3469 gpm (13,000 1/mm)

,

exclusive

of emergency overflows. December 1979 grab samples averaged 65 mg/i,

The Agency recommends that the variance be conditioned on a study

of discharge and background TSS levels (Bec. 4, 5).

CIPS currently proposes to route the blowdown to the ash

pond for sedimentation prior to discharge, if compliance with the

15 mg/l standard is to be required. This would cost about $300,000

and would involve piping changes which would take at least several

months to complete. The Board has not at this time considered

whether this is an acceptable control scheme.

The Board finds that requiring immediate treatment of blowdown

to meet the Rule 408(a) standard of 15 mg/i TSS would impose an

arbitrary and unreasonable hardship. The Agency recommends that

this variance extend through December 31, 1980.

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—3*-

This Opinion constitutes the Board’s findings of fact and

conclusions of law in this matter.

ORDER

Petitioner Central Illinois Public Service Company is granted

for its Meredosia power station a variance for the effluent stan-

dards for copper (total), iron (total) and iron (dissolved) and

total suspended solids (TSS) of Rule 408(a) of Chapter 3: Water

Pollution, subject to the following conditions:

1. The variance for copper (total), iron (total) and iron

(dissolved) will expire September 13, 1980 and will

cover only holler cleaning rinse water and air heater

wash discharges into the ash pond.

2. The variance for TSS will expire December 31, 1980 and

will cover only cooling tower blowdown and emergency

overflows from Unit 4.

3. Petitioner shall not discharge EDTA boiler chemical

cleaning solution into the ash pond.

4. PetitIoner shall conduct a study to determine treatment

capabilities of the ash pond. The study shall include

as a minimum data on pH of the ash pond, the constitu-

ents in the metal cleaning waste rinses, the concentra-

tion of the constituents and the volume of the metal

cleaning waste rinses discharged to the ash pond. A

summary of results shall be sent to the Agency by

November 29, 1980.

5. Petitioner shall conduct a study of background TSS con-

centration and Unit 4 discharges TSS concentrations.

This study shall be submitted to the Agency prior to

December 31, 1980.

6. The Agency, pursuant to Rule 914 of Chapter 3: Water

Pollution shall modify the NPT)ES Permit IL 0000116 con-

sistent with the conditions set forth in this Order.

7. Within forty—five days of the date of this Order, Peti-

tioner shall execute and forward to the Illinois Environ-

mental Protection Agency, Variance Section, 2200 Churchill

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—4—

Road, Springfield, Illinois 62706, a Certificate of

Acceptance and Agreement to be bound to all terms and

conditions of this variance. This forty-five day period

shall he held in abeyance for any period this matter is

being aptealed. The form of the Certificate shall be

as follows:

CERTIFICATION

I, (We),

_______________

read and fully understanding

hereby accept that Order and

of its terms and conditions.

SIGNED

TITLE

DATE

___________________,

having

the Order in PCB 80—25,

agree to be bound by all

IT IS SO ORDERED

I, Christan L. Moffett,

Control Board, her~y certify

a~optedon the

V~

day of

Clerk of the Illinois Pollution

the aho e Opinion and Order were

1980 by a vote of

Illinois Pollution Control Board