Date:
May
30,
2003
Subject:
Revised
MACT
Floor,
Regulatory
Alternatives,
and
Impacts
for
Small
Tanks
at
Chemical
Manufacturing
Facilities
Miscellaneous
Organic
NESHAP
EPA
Project
No.
95/
08;

From:
Brenda
Shine,
North
State
Engineering,
Inc.

To:
MON
Project
File
I.
Introduction
This
memorandum
describes
existing
and
new
source
MACT
floors
for
storage
tanks
with
capacities
less
than
10,000
gallons.

II.
Discussion
A.
Background
As
part
of
the
information
gathering
phase
for
the
development
of
this
standard,
EPA
collected
information
on
storage
tanks
associated
with
miscellaneous
organic
chemical
manufacturing
facilities.
However,
because
storage
tanks
are
commonly
defined
by
existing
regulations
as
having
capacities
greater
than
10,000
gallons,
we
did
not
specifically
request
information
for
tanks
with
capacities
of
less
than
10,000
gallons.
Recently,
we
have
tried
to
address
the
need
to
establish
MACT
floors
for
all
potential
sources
of
emissions,
including
small
tanks
(
those
below
10,000
gallon
capacity).
This
memorandum
presents
the
results
of
a
MACT
floor
analysis
for
small
tanks.

B.
MACT
Floor
for
Existing
Sources
Although
we
did
not
request
specific
information,
some
facilities
reported
information
for
tanks
with
capacities
of
less
than
10,000
gallons.
These
data
are
presented
in
Table
1.
A
total
of
19
tanks
from
8
facilities
were
reported
with
capacities
of
less
than
10,000
gallons.
For
comparison,
there
were
a
total
of
1,195
tanks
with
capacities
greater
than
or
equal
to
10,000
gal
at
132
facilities
in
the
MON
database.
We
recognize
that
our
subset
of
data
for
small
tanks
makes
up
a
relatively
small
fraction
of
overall
tanks,
and
that
the
amount
of
data
we
have
may
not
be
representative
of
the
industry
for
setting
the
MACT
floor.
Of
the
5
tanks
in
Table
1
that
are
reported
to
be
controlled,
the
first
4
are
located
at
the
same
facility,
while
tank
record
No.
5
is
2
located
at
a
second
facility.
Additionally,
Tank
record
No.
5
is
a
portable
tank,
based
on
subsequent
discussion
with
the
tank
operator.
1
In
setting
MACT
floors
for
less
than
30
sources,
EPA
bases
the
floor
on
the
best
5
facilities.
Therefore,
we
conclude
that
for
small
tanks,
there
is
essentially
a
"
no
emission
reduction
MACT
floor",
since
we
do
not
have
enough
data
to
set
the
floor
and
because
only
one
of
the
top
5
facilities
is
implementing
control.

C.
Regulatory
Alternative
Above
the
Floor
for
Existing
Sources
To
develop
a
regulatory
alternative
above
the
floor
for
small
tanks,
we
considered
the
analysis
that
had
been
conducted
for
our
populations
of
larger
tanks
(
greater
than
10,000
gallons).
2
In
this
analysis,
we
estimated
the
cost
effectiveness
of
controlling
horizontal
tanks
with
condensers,
since
these
could
not
be
fitted
with
the
more
cost
effective
floating
roof
controls.
The
same
is
true
for
small
capacity
(
less
than
10,000
gallon)
tanks,
and
therefore
we
considered
the
previous
cost
analysis
applicable.
The
analysis
consisted
of
estimating
uncontrolled
emissions
using
tank
throughputs
reported
in
the
Section
114
information
requests.
Generally,
tanks
close
to
10,000
gallons
and
a
HAP
partial
pressure
of
1
psia
were
estimated
to
be
generating
uncontrolled
emissions
on
the
order
of
less
than
1,000
lb/
yr,
with
a
few
exceptions
that
appear
to
result
from
uncharacteristically
high
throughputs.
The
same
effect
can
be
seen
in
Tank
Record
11
of
Table
1,
where
a
7,500
gallon
tank
was
reported
to
have
a
throughput
in
excess
of
12
million
gallons
a
year.
This
tank
experiences
numerous
turnovers
per
day
(
a
minimum
of
5
a
day),
indicating
that
its
service
is
more
likely
as
a
process
tank.
From
this
analysis,
we
concluded
that
controlling
tanks
with
capacities
less
than
10,000
gallons
per
day
and
storing
materials
with
a
HAP
partial
pressure
of
at
least
1
psia
would
not
be
cost
effective,
based
on
values
in
the
regulatory
analysis
on
the
order
of
$
200,000/
ton
to
$
300,000/
ton.
On
average,
condenser
control
per
storage
tank
would
consume
about
3,100
kwh/
yr
of
electricity,
and
generating
the
electricity
would
use
about
30.0
million
Btu/
yr
of
fuel
energy
(
coal)
and
generate
about
0.025
Mg/
yr
of
CO,
NO
x,
SO
2,
and
PM
10
emissions.
If
the
condensed
HAP
cannot
be
returned
to
the
tank
or
used
elsewhere,
then
about
1,000
lb
of
waste
would
be
generated
per
tank.
Therefore,
we
concluded
that
there
would
be
no
cost
effective
regulatory
alternatives
above
the
floor
for
smaller
tanks
with
the
throughput
and
HAP
partial
pressures
characteristics
in
Table
1.

D.
MACT
Floor
for
New
Sources
We
also
reviewed
the
data
in
Table
1
to
establish
a
MACT
floor
for
new
sources.
We
concluded
that
Tank
Record
No.
5
would
not
be
representative
of
similar
sources
because
it
is
a
portable
tank.
We
selected
the
characteristics
of
Tank
Record
No.
4
to
be
the
best
controlled
similar
source,
with
a
capacity
of
9,800
gallons
and
storing
a
material
with
a
HAP
partial
pressure
of
0.373
psia
(
rounded
to
0.4
psia).
We
considered
this
tank
to
be
more
stringently
controlled
than
the
8,000
gallon
tank
storing
a
material
with
a
HAP
partial
pressure
of
0.574
psia
because
partial
pressure
is
the
best
indicator
of
emission
potential,
and
controlling
a
lower
partial
pressure
is
an
indication
of
increasing
stringency.
This
tank
selected
as
the
new
source
MACT
floor
is
controlled
with
a
thermal
oxidizer
that
has
an
efficiency
in
excess
of
98
percent.
We
compared
this
tank's
characteristics
to
the
new
source
MACT
floor
for
larger
tanks,
which
was
set
at
95
percent
control
for
tanks
with
capacities
of
greater
than
10,000
gallons
and
storing
materials
3
Table
1.
Summary
of
Data
for
Small
Tanks
Record
Number
HAP
Partial
Pressure
(
psia)
Control
Device
Control
Efficiency
(%)
Capacity
(
Gallons)
Throughput
(
GPY)
Uncontrolled
Emissions
(
lb/
yr)
Controlled
Emissions
(
lb/
yr)

1
0.013
Carbon
Adsorber
70
6,000
6,660
0.88
0.27
2
0.373
Carbon
Adsorber
70
6,000
226,983
240.97
72.29
3
0.574
Thermal
Oxidizer
99
8,000
19,800
104.15
1.042
4
0.373
Thermal
Oxidizer
99
9,800
226,983
270.61
2.71
5
0.373
Thermal
Oxidizer
99
1,400
15,656
23.78
0.24
6
0.08
None
NA
8,000
30,900
19.44
19.44
7
0.002
None
NA
8,000
107,677
0.47
0.47
8
0.003
None
NA
7,807
1,038,000
3.52
3.52
9
0.003
None
NA
7,807
1,100,000
3.6
3.6
10
0.003
None
NA
7,807
1,038,000
3.6
3.6
11
0.02
None
NA
7,500
12,301,281
1,668.2
1,668.2
12
0.05
None
NA
500
100,000
2.6
2.6
13
0.05
None
NA
500
100,000
2.6
2.6
14
0.05
None
NA
500
100,000
2.6
2.6
15
0.05
None
NA
500
100,000
2.6
2.6
16
0.496
None
NA
8,750
133,874
216.1
216.1
17
0.496
None
NA
8,750
133,874
216.1
216.1
18
0.373
None
NA
6,000
51,375
87.6
87.6
19
0.373
None
NA
6,000
51,375
87.6
87.6
with
HAP
partial
pressures
of
0.1
psia
or
higher.
We
concluded
that
the
proposed
new
source
MACT
floor
for
larger
tanks
is
more
stringent
than
a
floor
based
on
98
percent
reduction
for
tanks
storing
material
with
a
HAP
partial
pressure
greater
than
or
equal
to
0.4
psia.
From
our
existing
population
of
tanks,
we
found
that
approximately
10
percent
greater
overall
reduction
would
be
achieved
by
controlling
all
tanks
with
HAP
partial
pressures
of
at
least
0.1
psia
at
95
percent
than
by
controlling
tanks
storing
materials
with
partial
pressures
greater
than
0.4
at
98
percent.
Additionally,
requiring
95
percent
control
allows
the
use
of
floating
roofs
and
consequently
provides
a
pollution­
prevention
option
in
lieu
of
requiring
end­
of­
pipe
control.
Therefore,
we
considered
the
new
source
MACT
floor
originally
developed
to
be
appropriate
(
95
percent
control
of
all
tanks
with
capacities
of
10,000
gallons
and
storing
material
with
a
HAP
partial
pressure
of
at
least
0.1
psia)
for
all
tanks.
4
III.
References
1.
Telecon.
R.
McDonald,
EPA,
with
J.
Bowers,
Cook
Composite
Products.
May
29,
2003.
Information
Regarding
Small
Xylene
Storage
Tank.

2.
Memorandum
from
D.
Randall
and
J.
Fields,
Midwest
Research
Institute,
to
the
Miscellaneous
Organic
NESHAP
Project
File,
July
31,
2000.
MACT
Floor,
Regulatory
Alternatives,
and
Nationwide
Impacts
for
Storage
Tanks
at
Miscellaneous
Organic
Chemical
Manufacturing
Facilities.
