RECE

WED

CLERK’S OFFICF

BEFORE THE POLLUTION CONTROL

BOARD

OF THE STATE OF ILLINOIS

MAR

1 ~2005

STATE

OF ILUNOIS

IN THE MATTER OF:

)

Pollution

Control

Boarc~

)

CITGO PETROLEUM CORPORATION and

)

PDV MIDWEST REFINING, L.L.C.,

)

)

PCB

05-85

Petitioners,

)

(Variance

—

Water)

)

V.

)

)

ILLINOIS ENVIRONMENTAL

)

PROTECTION AGENCY,

)

)

Respondent.

)

NOTICE OF FILING

To:

See Attached Service List

Please take notice that

on March

14,

2005,

we filed with the Office of the Clerk of the

Illinois

Pollution

Control

Board,

an

original

and

nine

copies

each

of

the

following

PETITIONERS’ POST-HEARING BRIEF REGARDING PETITION FOR

VARIANCE IN

CONNECTION WITH DISCHARGE OF

TOTAL DISSOL VED SOLIDS AND RESPONSES

TO ADDITIONAL

QUESTIONS FROM BOARD’S

TECHNICAL UNIT

copies ofwhich

are

hereby served upon you.

CITGO PETROLEUM CORPORATION and

PDV MIDWEST REFINING, L.L.C.

Jeffrey C. Fort

Letissa Carver Reid

SONNENSCHEINNATH & ROSENTHAL LLP

8000 Sears Tower

233

S. Wacker Drive

Chicago, IL

60606-6404

(312) 876-8000 (Phone)

(312) 876-7934 (Facsimile)

One of Its

THIS FILING IS BEING SUBMITTED

ON

RECYCLED PAPER

---

RE

C E ~V ED

CLERK’S

OFF~cF

BEFORE THE POLLUTION CONTROL BOARD

OF THE

STATE OF ILLINOIS

MAR

142005

STATE OF ILLINOIS

Pülj~t~on

Control Board

IN THE MATTER OF:

)

)

CITGO PETROLEUM CORPORATION and

)

PDV MIDWEST REFINING, L.L.C.,

)

)

PCB 05-85

Petitioners,

)

(Variance

—

Water)

)

v.

)

)

ILLiNOIS ENVIRONMENTAL

)

PROTECTION AGENCY,

)

)

Respondent.

)

PETITIONERS’

POST-HEARING

BRIEF

REGARDING

PETITION

FOR

VARIANCE

IN

CONNECTION WITH

DISCHARGE OF TOTAL DISSOLVED SOLIDS

AND

RESPONSES TO

ADDITIONAL QUESTIONS

FROM BOARD’S TECHNICAL UNIT

CITGO

Petroleum

Corporation

(“CITGO”)

and

PDV

Midwest

Refining,

L.L.C.

(“PDVMR”)

(hereinafter

collectively

referred

to

as

“CITGO”)

have

petitioned

the

Illinois

Pollution Control Board (the “Board”) for a variance that would

authorize the discharge of Total

Dissolved

Solids

(“TDS”)

subject to

certain conditions

that

have been approved by the Illinois

Environmental Protection Agency

(the “IEPA” or the “Agency”).

CITGO is

seeking

this water

variance

as

part

of a

significant

environmental

project.

CITGO

has

entered

into

a

Consent

Decree

with

the

United

States

Environmental

Protection

Agency

(the

“U.S.

EPA”)

and

the

environmental

authorities

for

four

other

states

including

Illinois

in

order

to

resolve

certain

alleged air quality violations

and

substantially reduce emissions of sulfur dioxide

(“SO2”)

and

nitrous

oxide (“NOx”).

The

Lemont Refinery

is

among three

refineries

for which

substantial

emission reductions will be

achieved as required by the Consent Decree.

The estimated annual

SO2

and

NOx

emission

reductions

for

the

Lemont

Refinery

are

15,000

and

1,100

tons

---

respectively.

(A

copy of the

Consent

Decree

executed

on

January

26,

2005

was

submitted

previously with CITGO’s pre-filed testimony as Exhibit 1.)’

In order to

comply with the emission requirements ofthe Consent Decree, CITGO must

install

a

wet

gas

scrubber

in

the

Fluidized

Catalytic

Cracking

Unit

(“FCCU”)

in

addition

to

substantial support equipment and controls.

Accordingly, a major construction project extending

approximately 20 months is

required.

(See Exhibit 2 (a copy of the compliance schedule for the

Lemont

Refinery

in

connection with

the Consent

Decree).

See

~

Exhibit

3,

which

contains

construction permit drawings depicting the new equipment

to

be

installed

and

a description of

the

same.)

CITGO

has

included

a

substantial

amount

of

equipment

design

adjustments

to

minimize

the

environmental

effect

of

wastewater

discharges

from

the

wet

gas

scrubber.

Nevertheless, installation ofthe wet gas scrubber will increase the amount of TDS in the treated

wastewater at the Lemont Refinery.

(Exhibit 4

is a copy ofthe petition for a TDS water variance

filed with the Board on November 8, 2004.)

One ofthe critical path items

is to obtain a construction permit from the water division of

the IEPA.

Exhibit

5

is

a copy ofthe application for that construction permit.2

On December 3,

2004,

CITGO

submitted

the

construction

permit

application,

consistent

with

the

overall

construction schedule.

In preliminary conversations with the water division ofthe IEPA, CITGO

learned of two

critical

issues

that

pose challenges for the Consent Decree schedule.

First,

the

IEPA will not

grant the construction permit without

also

issuing

a modified

National Pollutant

Discharge

Elimination

System

(“NPDES”)

permit.

Second,

because

there

has

been

an

exceedance ofthe TDS standard in

the past,

in association with snow

melt runoff, carrying road

salt and

similar compounds

into the streams, the IEPA could not

issue a NPDES

permit for this

All

exhibits

referred

to

herein

were

submitted

previously

with

CITGO

‘S

pre-filed

testimony

on

February 17,

2005,

unless otherwise indicated.

2

Page

3

(inadvertently

omitted

from

the

previously

filed

Exhibit

5)

of

the

Construction

Permit

Application for the Purge Treatment Unit (December 2004) is attached hereto as Exhibit

5.

2

---

project

unless

CITGO obtained

a

variance

from

the

Board.

Hence, the

variance petition was

filed soon after the Consent Decree was lodged.

Finally,

a negotiated compliance plan has been completed

to the satisfaction ofthe

IEPA

and was submitted as Exhibit 7.

This compliance plan requires that extensive TDS databe taken

from

the Des Plaines

River at the

1-55

Bridge

during

the winter months.

Subsequent

to

two

seasons of stream testing,

the Lemont Refinery will be able to

size the required holding tank or

basin

for the wet

gas scrubber discharge during periods of high salinity if that option is

needed.

The

project

for

the

retention

system

would

be

scheduled

to

begin

by

March

1,

2009,

with

completion

expected by

the winter season beginning December

1,

2009.

During the February

24,

2005 hearing, the IBPA expressed its support for the variance and its

conditions based upon

the supplemental information submitted

by CITGO

and

entered

into this

record.

Accordingly,

CITGO

requests

that

the

Board

find

that:

(1)

if the

instant

variance petition

is

not

granted,

CITGO will incur an arbitrary

and unreasonable hardship;

and

(2) the variance, if granted, will

not result in

significant injury to the public

or the environment.

STANDARD FOR GRANT OF VARIANCE RELIEF

Pursuant

to

Section

35(a)

of

the

Environmental

Protection

Act,

the

Board

has

the

authority

to

grant a variance from

one

of its

regulations whenever immediate compliance

with

such regulation would impose an

arbitrary or unreasonable hardship on the petitioner.

415

ILCS

5/35(a)

(2004);

City of Canton v.

Illinois Environmental

Protection Agency,

2002

WL

560970,

at

*1(111. Pollution

Control

Bd.

April 4,

2002).

In granting or denying

a variance,

the Board

must

balance

the

hardship

of compliance

with

its

regulations

on

petitioner

against

adverse

environmental impacts.

Marathon Oil Co.

v.

Environmental Protection Agency, 242 Ill.

App. 2d

200, 206, 610 N.E.2d 789, 793

(5th

Dist.

1993); Monsanto

Co.

v. Pollution Control Bd., 67 Iii.

2d

276,

292,

367 N.E.2d

684,

691

(1977).

The petitioner must

establish

that

the hardship it will

3

---

encounter

from

denial of the requested

variance will

outweigh any

injury

to

the public

or the

environment

from

the

grant

of the

same,

“.

.

.

and

only

if

hardship

outweighs

injury

does

evidence

rise to

the level of arbitrary or unreasonable.”

Marathon Oil

Co.,

242

Ill.

App.

2d

at

206, 610 N.E.2d at 793.

THERE

ARE

NO PRACTICAL ALTERNATIVES

THAT

WOULD REDUCE

THE

TDS

DISCHARGE

CAUSED

BY

INSTALLATION

OF

THE

REQUIRED

WET

GAS

SCRUBBER;

THEREFORE,

COMPLIANCE

WITH

THE

BOARD’S

EXISTING

TDS

WATER

QUALITY

STANDARD

WOULD

IMPOSE

AN

ARBITRARY

AND

SIGNIFICANT HARDSHIP

ON CITGO

Section

35(a)

of the

Environmental

Protection

Act

requires

the

Board

to

determine

whether CITGO has presented adequate proof that

it would

suffer an

arbitrary or unreasonable

hardship if required to comply with the Board’s TDS water quality standard.

415

ILCS

5/35(a)

(2004);

Marathon

Oil

Co.,

242

Iii.

App.

2d at

206,

610 N.E.2d at

793.

CITGO,

the U.S.

EPA

and

the IEPA

are parties

to

a

Consent Decree

to

substantially reduce

air

emissions.

CITGO

agreed

to

these

reductions

and

will

invest

more than

$120

million

at

the

Lemont

Refinery.

CITGO

is

subject

to

substantial

penalties

if

it does

not

meet

the

Consent

Decree

schedule.

Installation of the wet gas scrubber will increase the amount of TDS in the Lemont

Refinery’s

treated wastewater.

CITGO has investigated methods of avoiding the release

ofwastewater from the FCCU

to

the existing wastewater treatment system,

including a managed release program with the use

of

a

storm

water

basin

for

retention,

deep

well

disposal,

and

installation

of

evaporation

wastewater treatment technology.

None ofthese alternatives are practical.

At this time, the only option for a managed release program would

entail using the

storm

water basin

(“SWB”)

for retention.

The

SWB

is

used

to

collect

site storm

water

runoff and

drainage

from

naturally

existing

waterways.

A

marked

increase

in

storm

water volume

has

occurred due to

residential developments near the northwest facility boundary.

The runofffrom

4

---

these developments

feeds

into the naturally existing waterways that terminate within the Lemont

Refinery’s boundaries

and

ultimately

end

up

in

the

SWB.

Due

to

a

special

condition

in

the

Groundwater Management Zone Approval

Letter, issued by the Bureau ofWater Permit section,

the SWB water level must be maintained below

12 ‘9” due to the groundwater gradient.

Because

of the

existing

difficulties

associated

with

maintaining

the water

level

below

12’9”

with

the

additional

burden

created

by

the

increased

storm

water

runoff

volume

from

residential

developments,

to

try

to

retain

the

wet

gas scrubber

effluent

during

periods

of snowmelt

and

deicing would not be a viable option.

As discussed in CITGO’s variance petition (Exhibit

7), deep well disposal is not a viable

alternative because deep well disposal would constitute a Class I injection well.

($~

Exhibit 13;

see

also

February 24,

2005 Hearing Transcript

at 39:9

-

39:24.)

Class

I injection

wells are not

permittable in

northeastern

Illinois

because no

cap rock

exists

over

the depth

where disposal

wells

are drilled.

($~

Exhibit

13.)

Technologies

for removal of sodium

sulfate from

a

dilute

aqueous

stream

are

limited.

Electrodialysis

has

in

no

case

been applied

in

the

chemical

or

refinery industries on

the scale required at

the

Lemont Refinery.

Biological

sulfate reduction

theoretically

is possible;

however,

biological

sulfate reduction will not

reduce the overall

TDS

concentration

simply by

replacing

the sulfate ions

with

carbonate ions.

The concentration

of

sodium sulfate is too high for reverse osmosis concentration, as scaling problems would

develop.

The

only

technology

potentially

available

would

be

evaporation.

Evaporation

is

an

energy intensive

approach, which

would

result in

increased

carbon dioxide

emissions

into the

atmosphere.

The

evaporation

process

would

require

a

multi-effect

evaporator

to

minimize

energy consumption.

A falling

film evaporator with mechanical vapor recompression (“MVR”)

is

the most

energy efficient approach.

Subsequent crystallization would produce a dry sodium

sulfate by-product.

Whether this

by-product would

be of sufficient purity to

have

any market

5

---

value has not been determined.

~

Exhibit

7,

attachment A (CITGO’s

Petition

for Variance

filed November

8,

2004),

which

depicts

a

conceptual process

flow

diagram of a

falling

film

evaporator with MVR; ~

~

Exhibit

14

(a description of evaporation costs) and February 24,

2005 Hearing Transcript at 40:12

-

40:18.)

The capital cost in 2004 dollars for the application of such technology to this wastewater

stream

is

on

the order of $7

million.

Operating costs,

including depreciation,

are

estimated at

$1

million per year.

Forty percent of this $1

million amount represents energy costs.

This cost

estimate assumes the Lemont Refinery has sufficient

steam capacity, and

it also

assumes that

a

new

boiler will not

be

required.

Moreover,

CITGO

is

not

aware

of a

situation where

such

a

massive evaporation system has been constructed or operated.

CITGO

also

notes the increased

energy demand and emission impact that such an

evaporation system would require.

Additional

investigation would be necessary before such an approach could be pursued.

($~

Exhibit 14.)

Requiring

CITGO

to

install

evaporation wastewater treatment for the wet

gas

scrubber

discharges into the wastewater system

would

impose an

arbitrary

and

unreasonable

hardship.

Such

installation

is

not

practical,

and

such

installation

certainly

is

not

practical

on

the

time

schedule dictated by the Consent Decree.

CITGO is not the cause of any water quality standard

exceedance.

Further,

CITGO is

investing

substantial monies in

the Lemont Refinery to

reduce

air

emissions

as

well

as

significantly

reducing

the

overall

environmental

releases

from

the

Lemont Refinery.

In addition,

the wastewater discharge at issue

is relatively modest; indeed, the

relative

contribution

of

this

project

is

within

error

range

of

the

sampling

method.

(See February 24,

2005

Hearing

Transcript

at

35:5

-

36:8.)

Hence,

requiring

control of the

increased

wastewater

discharge

would

impose

an

arbitrary

and

unreasonable

hardship

on

CITGO.

6

---

GRANT

OF

THE

REQUESTED

VARIANCE

WILL

NOT

RESULT

IN

SIGNIFICANT

INJURY TO

THE PUBLIC OR THE ENVIRONMENT

The hardship to

CITGO ofcompliance with the TDS water quality standard is substantial.

At the same time, there is no

cognizable benefit to

the public or the environment by compelling

such compliance.

TDS

is

composed of a variety of anions and

cations, thus,

there are no “toxicity” values

that

can be applied to

the generic

TDS parameter.

For

General

Use

waters,

TDS, sulfates

and

chlorides are regulated.

The IEPA has indicated that technical data supported elimination of the

TDS water quality standard and increasing the sulfate

General

Use

limit to

approximately

1,800

mg/L.

(~

Exhibit

10

(information provided to

the stakeholders by

the

IEPA on this issue)).

Additional

toxicity testing

is

being completed by the

U.S.

EPA.

If these results

are consistent

with

the

JEPA’s

previous

research,

the

IEPA

may

propose

these

changes

in

water

quality

standards in the fourth quarter of2005.

Sodium sulfate, at the proposed levels discharged, will not impact the aquatic community

in

the Chicago Sanitary

and

Ship

Canal or in

the Des Plaines River.

(~

February 24,

2005

Hearing Transcript at 37:4

-

38:4.)

There

is no

adverse effect on

aquatic life due

to TDS

and

sulfate levels projected here.

Therefore,

the grant of the requested variance will not

result

in

significant

injury

to

the

public

or the

environment.

(See

~

Exhibit

6

(James

E.

Huff’s

December 2004 report titled “Impact of CITGO’s Proposed Discharge on Water Quality”)).

Investigations

related

to

water

quality

standards

for TDS

have

been conducted

by

the

IEPA

and

are

ongoing

by

the

U.S.

EPA.

The

IEPA

has proposed that

TDS

be

removed

as a

water quality parameter and

sulfate water quality

standards be

increased to

1,800 mg/L.

Under

these proposed standards,

there would

be

no

water quality

exceedance

even during

snow

melt

conditions.

Therefore, there may be no

need for further controls on

CITGO’s

TDS wastewater

discharge.

7

---

Further

responses

to

questions

from

the

Board’s

technical

unit

are

included

in

Attachment A hereto.

WHEREFORE,

CITGO

requests

that

the

Board

find

that:

(1)

adequate

proof that

immediate compliance with

the Board’s TDS water quality

standard would impose an

arbitrary

and

unreasonable

hardship;

and

(2) grant

of the requested variance

would pose no

significant

injury

to

the public

or the

environment.

Finally,

CITGO

requests

that

the

Board

grant

the

requested variance.

Dated: March 14, 2005

Respectfully submitted,

By:

Jeffrey C. Fort

Letissa Carver Reid

SONNENSCHEIN NATH & ROSENTHAL LLP

8000 Sears Tower

233

South Wacker Drive

Chicago, Illinois

60606-6404

(312) 876-8000 (Phone)

(312) 876-7934 (Facsimile)

14425764.6

THIS FILING IS BEING SUBMITTED

ON RECYCLED PAPER

for CITGO PETROLEUM

CORPORATION and PDV MIDWEST

REFINING, L.L.C.

8

---

CERTIFICATE OF SERVICE

The undersigned, an attorney, certifies that I have served upon the individuals named on

the attached Notice ofFiling true and correct copies of

PETITIONERS’ POST-HEARING

BRIEF REGARDING PETITION FOR VARIANCEIN CONNECTION WITH

DISCHARGE OF TOTAL DISSOLVED SOLIDS AND RESPONSES TO ADDITIONAL

QUESTIONS FROM BOARD’S TECHNICAL

UNIT via

Federal Express, on March

14, 2005.

__.11

,~--•——)

-.---—

7

\

/

\

.;~-~_

f_~_—’

(

_____________________________

‘ffrey

C~Foa~\

Letissa Carver Reid

---

VIA HAND DELIVERY

Dorothy Gunn

Clerk ofthe Board

Illinois Pollution Control Board

100 West Randolph Street

-

Suite 11-500

VIA

FEDERAL EXPRESS

Bradley Halloran

Hearing Officer

Illinois Pollution Control Board

100 West Randolph Street

Suite 11-500

Chicago, Illinois 60601

James Allen Day, Esq.

Illinois EPA

1021

Grand Avenue east

P.O. Box 19276

Springfield, Illinois 62794-9276

---

m

---

ATTACHMENT A

CITGO’S RESPONSES TO ADDITIONAL QUESTIONS FROM ILLINOIS

POLLUTION CONTROL BOARD’S

TECHNICAL UNIT

1.

Exh.

5,

the Construction Permit Application for

the Purge

Treatment

Unit

(December

2004),

appears to be missingpage

3from the original and copiesfiled with the Board.

Page

3

(inadvertently

omitted

from

the previously filed Exhibit

5)

of the

Construction Permit

Application for the Purge Treatment Unit (December 2004) is attached hereto as Exhibit

5.

2.

Flow valuesfor the PTU appear in

severalplaces in

the testimony and hearing exhibits.

Would you please reconcile

theflow

values

below,

indicating perhaps

which

represent

PTUinfluent or effluent...

In

designing

new process

facilities,

the

loadings are

refined

as

the

design

proceeds

through

various stages.

In addition, there are design loadings and anticipated actual loadings.

Treatment

facilities typically are designed with a safety factor, as occurred in the FCCU Wet Gas Scrubber,

and is

standard engineering practice.

Therefore,

design loadings typically are above anticipated

actual loadings

to

assure the

facilities will not be

undersized.

The different loadings identified

by

the

Board’s technical

staff reflect

these considerations.

Specifically,

the

331,000

gpd

and

0.33

MGD (which is the same value, just rounded to two

significant digits), is a DESIGN value,

used for sizing the equipment.

The 274,000

gpd

is the ACTUAL ANTICIPATED

AVERAGE

FLOW

from

the

FCCU

Wet

Gas

Scrubber,

based

on

the

historical

refinery production.

As

Mr. Harmon

testified, currently there are

no

plans

to

increase

the Lemont

Refinery production

from

the

historical

level.

The

0.38

MGD

(and

375,000

gpd,

which

is

the

same number, just

rounded to two significant digits) was one of the earlier DESIGN AVERAGE FLOW numbers,

which subsequently was revised down to 0.33

MGD (or 331,000 gpd), based on further process

design work, which allowed for a reduction in water consumption.

3.

Flow contributions

to

Outfall

001

in

addition

to

the

PTU also

appear

in

the

hearing

exhibits:...

---

Please

indicate

what flows

constitute

the

3.6

mgd

at

2,160

mg/L

TDS

referenced

in

Exh.

6.

In the remaining flows

to

Outfall

001

listed in

Exh.

11,

other

than

the 3.6 mgd

and 0.27 mgd shown in

Exh. 6footnote

2,

are there any TDS contributions?

If so, would

you please indicate concentration andflow?

The sources constituting the 3.6 MGD are the same sources listed in Exhibit

11, Pg

1

of4 ofthe

amended

NPDES

permit

renewal.

The

3.6

MGD

reflects

the

typical

discharge

at

low

flow

stream conditions.

4.

The TDS design loadingand concentration are referenced in the hearing exhibits...

The TDS

loadings

on the

PTU

of 215,000

lb/day

and

274,000

gpd

are

the anticipated

actual

average

values.

This

translates

into

a

TDS

concentration

of 94,000

mg/L.

The

system

is

designed,

as described above, to handle an

average

flow of331,000 gpd.

The Schedule N used

76,000 mgIL and a flow of331,000

gpd, which equates to 210,000 pounds per day ofTDS.

The

minor difference in pounds ofTDS per day is due to

refined design information.

The difference

in

flow

reflects

the

difference

in

DESIGN

(0.33 1

MGD)

versus

ACTUAL

ANTICIPATED

(0.274 MGD) flows.

In summary, the best estimate ofanticipated flow and loading at this point

is

274,000

gpd

containing

215,000

pounds

per

day

of

TDS.

The

sulfates

merely

are

a

stoichiometric fraction ofthis, 67

ofthe TDS.

Using the loadingfigures provided in Exh

6 at

2,

what would

be the

TDS

concentration

in the PTU effluent?

The 274,000 gpd is the same as 0.274 MGD.

The concentration from the PTU therefore will be:

(215,000 pounds/day)

/

(8.34)(0.274 MGD)

=

94,000 mg/L

What

is

the

expected

concentration

of

TDS

in

the

effluent from

the

PTU

before

it

combines with otherflows to

Outfall 001?

The 274,000

gpd is the same as 0.274 MGD.

The concentration from the PTU therefore will be:

(215,000 pounds/day) / (8.34)(0.274 MGD)

=

94,000 mg/L

2

---

5.

Exh.

6 at 2

indicates

the sulfate design

loadingfrom

the PTU to

the receiving stream

is

142,000

lbs/day.

Exh.

14

at

1

uses

a

sodium

sulfate

loading of 304,000

lbs/day

to

calculate costs for

a falling film

evaporator.

Would you please

describe

the reason

behind using a higher loading to calculate the evaporator costs?

Exhibit

6

presents

the anticipated

average

loadings

to

the receiving

stream.

Exhibit

14

is

the

DESIGN loading for the equipment.

The 304,000 pounds per day of sodium sulfate is equivalent

to

205,000 pounds per

day as

sulfate.

As

explained in

the earlier questions,

equipment design

takes into account maximum loadings, and not just the average loadings.

3

---

-‘N

m

03

---

2.

PROCESS DESCRIPTION

A

purge stream from the

WGS

containing ammonia will be directed to

a new building

(120

feet

long

and

45

feet

wide)

located

east

of the

existing

wastewater

treatment

plant.

The purge

treatment unit (PTU) is sized to

handile a maximum flow rate of 300 gpm, and

a design average

flow rate of 230

gpm.

Two

WGS

technologies

are

still

under

consideration.

One

system

includes sulfite oxidation

step

as an integral part ofthe WGS.

The second system

includes an

oxidation step external to

the WGS.

Ifthe later is selected, an

external air oxidation step will be

added

to

the

PTU

producing

sodium

sulfate.

The

WGS

that

includes

an

oxidation

system

integral to

the WGS is likely to be selected, so the process description presented herein assumes

describes this

system.

The conversion of sodium sulfite

to

sodium sulfate (sulfite oxidation)

occurs in the base of the

WGS instead of an external PTU.

Caustic

is

added

to the scrubbing

solution

and recirculated

through external educators that draw the required air for oxidation.

Caustic

is also used to adjust

the pH from the WGS operating range (6.2 to 9.0) to the range of

9-9.5.

The oxidation system

includes facilities to reliably control the pH ofthe oxidation

system.

The oxidized purge stream

from

the

WGS

is

sent

directly

to

the

Auto-Pulse

Tubular

Backpulse

Filter,

one

norrnaily

operating

and

one

spare

to

ensure

uninterrupted

service.

The

Auto-Pulse

Filter

removes

suspended solids

from

the purge

stream.

Internals for the filter will be made from

316L

SS.

Pl~i~2ir

will be supplied to

the filter to provide the pulsating necessary to accommodate solids

removal.

A bypass line is provided which will be utilized when the filter is being pulsated with

plart air.

The sludge from the Auto-Pulse Filter is

sent to a new Sludge Tank through a gravity flow line.

Two sludge pumps

(one spare) areprovided to pump the sludge from the tank to the two Oberlin

Filters, one

normally operating

and one spare to

ensure uninterrupted service.

Plant air will be

supplied

to

the

Oberlin

filter

to help

facilitate the

solids

dewatering.

The filtrate

from

the

Oberlin Filter will be sent through a new line to

a new DewateringBasin

Sump where it will be

collected and them pumped by two new Dewatering Basin Sump Pumps (one spare) back to the

line

going into the Auto-Pulse

Filters.

The Dewatering Basin Sump

and the associated

pumps

will have 316L SS

as the material of construction.

There is

also a recirculation line provided to

send the filtrate to

the inlet line of the Oberlin filters.

The Oberlin ifiter system is elevated such

that the

dry solid cake

discharge can be

collected

to

20

cu

yd roll off boxes that

can then be

trucked to a landfill for disposal.

All piping

around the Auto-Pulse Filter

system,

the Oberlin Filter system

and

the Dewatering

Basin sump will be 316L SS.

The effluent from the Auto-Pulse Filter, which will contain less than

15

mgfL Total

Suspended

Solids,

will be

sent

to

a new

open

top

PT(J Effluent

Tank

that

will be

equipped with

a new

Agitator.

Both the agitator and tank will have carbon steel as their material of construction.

A

new sodium hypochiorite storage tank will also be provided; The tank will be equipped with two

new metering pumps

(one

spare).

These

pumps

will

send sodium

hypochlorite

to

the

PT(J

Effluent

Tank.

Aimnonia

reduction

will

be

facilitated

through

the

breakpoint

chlorination

process

controlled by

Oxidation-Reduction

Potential

(ORP)

probes.

The

PTU effluent

will

3