ILLINOIS POLLUTION CONTROL BOARD

April

18,

1974

MEDUSA CORPORATION,

Petitioner,

vs.

PCB 74—54

ENVIRONMENTAL

PROTECTION

AGENCY,

Respondent.

Lowell J. Gettman, Attorney for Petitioner

Michael Ginsberg, Attorney for EPA

OPINION AND ORDER OF THE BOARD

(by Mr.

Henss)

On January 23, 1974 Medusa Corporation filed a Motion for

Reconsideration of the Order entered by the Board on November 15,

1973 in Medusa Corporation vs. Environmental Protection Agency,

PCT3

73—337.

By that

Order,

Medusa was granted variance from

Rules 202(b),

203(b),

203(d) (3)

and 203(i)

of the Air Pollution

Control Regulations for a period of one year pending installation

of a baghouse to control particulate emissions from four clinker

coolers at its Dixon cement manufacturing p1ant~

In lieu of the baghouse control system previously approved,

Medusa now proposes

to install a gravel bed filter system to

control the particulates

from the clinker cooler.

We consider

the current Motion to be

a request for modification in the

nature of

a new variance petition.

We approve the modification

and will issue the Order necessary

to incorporate the change.

As shown in Exhibits B and

C

attached

to

the

Motion,

Medusa

was

reviewing and evaluatinq the possible application of the

gravel bed filter control equipment even pr~iorto our November 15,

1973 Opinion and Order.

On October

5,

1973,

the day following

the public hearing in PCB 73-337, Medusa received a proposal

for the gravel bed filter from Envirex, Inc.,

sqle United States

supplier of gravel bed filters.

On Octob~r30~1973Medusa

issued its Letter of Intent

to purchase the gravel bed filter

system.

The purchase order

for the design,

fabrication and

delivery of the gravel bed filter system

was

issued on January

4,

1974.

Medusa

failed

to

inform

the

Board

of

the

~ossibility

of

change in control equipment although this chanqe was reasonably

anticipated for over

a month before the adoption of our Opinion

and Order.

12—111

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—2—

The new system consists of several filter units which are

connected by preliminary dusty gas and clean gas ducts

in parallel.

Particulate laden air expands

as it enters the dusty gas duct.

This allows coarse dust to be removed as the velocity is reduced.

The air then enters a preliminary centrifugal separator where

an additional amount of coarse dust is separated for removal

via counterweighted valves.

The partially cleansed air then

spirals upward through a vortex tube into the gravel bed filter

chamber.

There the dust is collected upon and within the

interstices of the gravel-like granules.

The cleansed air then

passes through a screen into

a clean air chamber and is subse-

quently discharged into the atmosphere.

Envirex Inc. recommends

this system over the baghouse system

for several reasons:

low maintenance cost due to minimum of

moving parts, elimination of need to replace cloth bag filters,

capability

to withstand temperatures in excess of

9000

F., no

significant performance change due to variation in size of dust

particles,

filter performance does not deteriorate with age,

no

significant wear on parts, and simple controls.

Operation of the gravel bed filter at the Dixon plant has

been guaranteed by Envirex to reduce the dust concentration

from

3 gr/ACF to 0.0078 gr/ACF

(99.74

reduction)

at 185,000

ACFM.

Medusa contends that the gravel bed filter system can

be installed and in operation within the constraints of their

original compliance

schedule.

This schedule anticipated com-

pliance with applicable regulations by March 31,

1975.

The

Agency recommends granting this variance mQdification stating

that the new system will be just

as effective or more effective

than that provided by the original plan.

We agree and shall

modify our November 15, 1973 Order accordingly.

ORDER

It

is the Order of the Board that:

1.

Medusa Corporation is granted variance from

Rules 202(b),

203(b),

203(d) (3),

203(i)

of

the Air Pollution Control Regulations for

four

(4) clinker coolers at its Dixon cement

manufacturing plant until April

18,

1975 pending

installation of

a gravel bed filtration system

to control particulate emi3sions from the four

clinker coolers.

2.

Medusa shall post

a bond in the amount of

$100,000

in

a form acceptable

to the Environmental

Protection Agency, such bond to be forfeited in

the eventthe gravel bed filtration system is not

installed as described during these proceedings.

The bond shall be posted by May 15, 1974 and shall

be in lieu of the bond required under our prior

Order of November 15, 1973.

Bond shall be mailed

12—112

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—3—

to Fiscal Services Division, Illinois EPA,

2200 Churchill Road,

Springfield,

Illinois

62706.

3.

Beginning May

1,

1974, Medusa shall submit

quarterly progress reports to the Variance

Section of the Environmental Protection

Agency.

Such reports shall detail all

progress towards completion of the gravel bed

filtration system.

4.

Medusa Corporation shall attempt to expedite

completion

of the gravel bed filtration

system and shall report such efforts in its

quarterly report to the Agency.

5.

Medusa shall apply

for all necessary con-

struction and operating permits for its Dixon

plants.

I,

Christan L. Moffett, Clerk of the Illinois Pollution Control

Board, hereby certify the above Opinion and Order was adopted

this

j~ç~

day of

~

,

1974

by

a

vote

of

to~

‘I