OLD
and
MON
 
Assigning
Storage
Tanks*

*
Note
this
document
represents
an
updated
and
modified
position
from
the
American
Chemistry
Council's
OLD
comments
at
page
20.
Clear
Applicability
­
"
Subject
to"
versus
"
Controlled
Under"
EPA
should
eliminate
the
overlap
between
OLD
and
MON
and
other
source
categories
by
delineating
the
OLD
boundary
by
excluding
equipment
and
operations
that
have
been
previously
determined
to
be
part
of
another
40
CFR
Part
63
standard,
specifically
including
the
MON.
Emission
points
that
have
already
been
determined
to
belong
to
a
separate
source
category
(
including
those
which
EPA
has
already
determined
that
controls
are
not
justified
under
the
MACT
rule
for
that
source
category)
must
not
be
included
in
the
OLD
source
category.

I
ntervening
Storage
Tank
The
"
intervening
storage
tank"
concept
has
been
used
in
many
other
Part
63
standards,
including
the
HON
(
§
63.100(
g)(
3)),
the
Group
I
Polymer
&
Resins
MACT
(
§
63.480(
g)(
7)),
and
the
Group
IV
Polymers
&
Resins
MACT
(
§
63.1310(
g)(
7)).
It
was
first
introduced
in
the
August
26,
1996
revisions
to
the
HON,
where
EPA
agreed
that
the
distinction
between
storage
vessels
used
for
product
storage
and
vessels
used
more
for
purposes
of
facilitating
product
distribution
was
ambiguous
and
needed
clarification.
EPA
stated
that
their
solution
to
this
problem
".
.
.
will
result
in
assignment
of
storage
vessels
in
a
manner
consistent
with
normal
management
of
facility
operations.
Specifically,
it
is
expected
that
storage
vessels
that
are
an
integral
part
of
operation
of
a
CMPU
subject
to
the
HON
will
be
regulated
under
the
HON
and
that
storage
vessels
that
are
used
to
facilitate
product
distribution
will
be
regulated
as
part
of
the
organic
liquids
distribution
source
category
and
not
under
the
HON."
61
Fed
Reg.
at
43701
(
August
26,
1996).
A
similar
logic
applies
to
MON
units.

Recommendation
Where
a
bulk
tank
in
a
tank
farm
area
has
received
organic
liquids
from
outside
the
plant
site
and
feeds
that
material
to
another
storage
tank
at
a
MON
process
unit
(
an
"
intervening
storage
tank"),
the
bulk
tank
is
assigned
to
the
organic
liquid
distribution
MACT,
and
the
"
intervening
storage
tank"
to
the
MON
process
unit.
This
can
be
illustrated
in
the
drawing
below.

Both
Tank
1
and
Tank
2
are
located
in
the
Organic
Liquids
Distribution
area.
Tank
1
feeds
into
a
smaller
storage
tank
located
at
the
process
unit
(
an
"
intervening
storage
tank"),
as
well
as
to
other
process
units
at
the
facility.
Tank
2
feeds
directly
into
the
MON
process
unit.
Tanks
3
and
4
are
located
at
the
process
unit.
In
this
illustration,
Tanks
1
is
subject
to
the
OLD
rule,
as
it
is
the
bulk
tanks
for
the
facility.
Tanks
2,
3
and
4,
however,
would
be
part
of
the
process
unit,
and
subject
to
any
MACT
standard
that
applies
to
that
unit.
They
would
not
be
subject
to
the
OLD
MACT.
Tank
assignments
are
made
based
ON
USE
not
geography.
T
a
n
k
1
T
a
n
k
2
T
a
n
k
3
T
a
n
k
4
T
r
a
n
s
fe
r
O
p
e
ra
t
io
n
D
i
s
t
r
ib
u
t
i
o
n
A
r
e
a
P
r
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c
e
s
s
U
n
i
t
P
r
o
c
e
s
s
U
n
i
t
T
o
o
th
e
r
p
r
o
c
e
s
s
u
n
i
t
s
O
r
g
a
n
ic
L
i
q
u
i
d
f
r
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m
O
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f
­
s
i
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Drawing
2
