Date:
August
27,
2003
Subject:
Evaluation
of
Concentration­
Based
Applicability
Cut­
Offs
for
the
Plywood
and
Composite
Wood
Products
Industry
EPA
Contract
No.
68­
D­
01­
079;
WA
No.
003
RTI
Project
No.
08550­
000­
003
From:
Becky
Nicholson
Katie
Hanks
To:
Mary
Tom
Kissell
ESD/
WCPG
(
C439­
03)
U.
S.
Environmental
Protection
Agency
Research
Triangle
Park,
NC
27711
I.
Introduction
The
U.
S.
Environmental
Protection
Agency
(
EPA)
proposed
national
emission
standards
for
hazardous
air
pollutants
(
NESHAP)
for
the
plywood
and
composite
wood
products
(
PCWP)
source
category
on
January
9,
2003.1
Plywood
and
composite
wood
products
include
the
following:
medium
density
fiberboard
(
MDF),
particleboard
(
PB),
hardboard
(
HB),
fiberboard,
oriented
strandboard
(
OSB),
softwood
plywood
and
veneer,
hardwood
plywood
and
veneer,
engineered
wood
products
(
EWP),
and
kiln­
dried
lumber.
The
proposed
NESHAP
includes
six
different
compliance
options
for
PCWP
process
units
equipped
with
add­
on
controls;
these
six
options
are
shown
in
Table
1.2
Two
other
compliance
options
were
included
in
the
proposal­­
emissions
averaging
and
production­
based
emission
limits.
The
production­
based
emission
limits
are
shown
in
Table
2.3
All
of
these
compliance
options
were
developed
based
on
an
analysis
of
the
maximum
achievable
control
technology
(
MACT)
floor
for
PCWP
process
units.
2
The
American
Forest
and
Paper
Association
(
AF&
PA)
requested
that
EPA
include
a
concentrationbased
applicability
cut­
off
(
below
which
affected
PCWP
process
units
would
not
be
required
to
control
hazardous
air
pollutant
[
HAP]
emissions)
in
addition
to
the
options
shown
in
Tables
1
and
2
and
the
emissions­
averaging
compliance
option.
4,5
2
TABLE
1.
ADD­
ON
CONTROL
SYSTEMS
COMPLIANCE
OPTIONS
(
PRE­
PROPOSAL)

For
each
of
the
following
process
units...
You
must
comply
with
one
of
the
following
six
compliance
options
by
using
an
emissions
control
system...

Fiberboard
mat
dryer
heated
zones
(
at
new
affected
sources
only);
Green
rotary
dryers;
Hardboard
ovens;
Press
predryers
(
at
new
affected
sources
only);
Pressurized
refiners;
Tube
dryers;
Reconstituted
wood
product
board
coolers
(
at
new
affected
sources
only);
Reconstituted
wood
product
presses;
Softwood
veneer
dryer
heated
zones;
and
Strand
dryers
(
1)
Reduce
emissions
of
total
HAP,
measured
as
THC
(
as
carbon),
a
by
90
percent;
or
(
2)
Limit
emissions
of
total
HAP,
measured
as
THC
(
as
carbon)
a,
to
20
parts
per
million
by
volume,
dry
(
ppmvd);
or
(
3)
Reduce
methanol
emissions
by
90
percent;
or
(
4)
Limit
methanol
emissions
to
less
than
or
equal
to
1
ppmvd
if
uncontrolled
methanol
emissions
entering
the
control
device
are
greater
than
or
equal
to
10
ppmvd;
or
(
5)
Reduce
formaldehyde
emissions
by
90
percent;
or
(
6)
Limit
formaldehyde
emissions
to
less
than
or
equal
to
1
ppmvd
if
uncontrolled
formaldehyde
emissions
entering
the
control
device
are
greater
than
or
equal
to
10
ppmvd.

a
You
may
choose
to
subtract
methane
from
THC
as
carbon
measurements.

TABLE
2.
PRODUCTION­
BASED
COMPLIANCE
OPTIONS
(
PRE­
PROPOSAL)
a
For
the
following
process
units...
You
must
meet
the
following
production­
based
compliance
option
(
total
HAPb
basis)...

(
1)
Fiberboard
mat
dryer
heated
zones
(
at
new
affected
sources
only)
0.022
lb/
MSF
1/
2"

(
2)
Green
rotary
dryers
0.058
lb/
ODT
(
3)
Hardboard
ovens
0.022
lb/
MSF
1/
8"

(
4)
Press
predryers
(
at
new
affected
sources
only)
0.037
lb/
MSF
1/
2"

(
5)
Pressurized
refiners
0.039
lb/
ODT
(
6)
Tube
dryers
0.26
lb/
ODT
(
7)
Reconstituted
wood
product
board
coolers
(
at
new
affected
sources
only)
0.015
lb/
MSF
3/
4"

(
8)
Reconstituted
wood
product
presses
0.30
lb/
MSF
3/
4"

(
9)
Softwood
veneer
dryer
heated
zones
0.022
lb/
MSF
3/
8"

(
10)
Strand
dryers
0.18
lb/
ODT
For
the
following
process
units...
You
must
meet
the
following
production­
based
compliance
option
(
total
HAPb
basis)...

3
a
You
may
not
use
an
add­
on
control
system
to
meet
the
production­
based
compliance
options.
b
Total
HAP
is
defined
here
as
the
sum
of
emissions
of
acetaldehyde,
acrolein,
formaldehyde,
methanol,
phenol,
and
propionaldehyde.
lb/
ODT
=
pounds
per
oven
dried
ton;
lb/
MSF
=
pounds
per
thousand
square
feet
with
a
specified
thickness
basis
(
inches).

II.
Overview
of
AF&
PA's
Recommendation
In
December
2001,
the
AF&
PA
submitted
a
white
paper
to
EPA
which
outlined
the
industry's
recommendation
and
rationale
for
including
a
50
parts
per
million
by
volume
(
ppmv)
HAP
applicability
cut­
off
in
the
PCWP
NESHAP.
4
The
AF&
PA
then
resubmitted
their
recommendation
in
their
comments
on
the
proposed
rule
in
March
2003.5
The
50
ppmv
concentration
cut­
off
suggested
by
AF&
PA
would
be
based
on
the
combined
concentration
of
the
six
most
predominant
HAP
emitted,
namely,
acetaldehyde,
acrolein,
formaldehyde,
methanol,
phenol,
and
propionaldehyde.
These
six
HAP
represent
"
total
HAP"
as
defined
for
the
production­
based
emissions
limits
and
for
the
emissions
averaging
provisions.

In
their
white
paper
and
comments
on
the
proposed
rule,
AF&
PA
cited
three
reasons
why
EPA
should
add
the
concentration­
based
applicability
exemption
to
the
PCWP
proposal:
(
1)
court
cases
have
established
EPA's
authority
to
create
"
de
minimis
exemptions;"
(
2)
EPA
has
promulgated
several
NESHAP
with
concentration­
based
applicability
cut­
offs;
and
(
3)
the
applicability
cut­
off
is
justified
due
to
the
expected
high
cost
of
the
PCWP
rule
and
the
"
substantial
negative
environmental
impacts"
that
would
result
from
implementation
of
the
rule
without
such
a
cut­
off.
However,
AF&
PA
did
not
cite
any
NESHAP
that
explicitly
relied
upon
a
"
de
minimis"
rationale
to
exempt
emissions
from
MACT
standards,
nor
any
court
cases
holding
that
EPA
had
such
authority
when
promulgating
standards
under
section
112(
d)
of
the
Clean
Air
Act.
The
AF&
PA
also
did
not
establish
any
common
link
between
the
industries
regulated
by
those
other
NESHAP
with
concentration­
based
applicability
cut­
offs
and
the
PCWP
industry,
nor
any
link
between
the
proposed
50
ppmv
applicability
cut­
off
and
the
MACT
floor
analysis
for
the
PCWP
industry.
The
remainder
of
this
memorandum
evaluates
the
appropriateness
of
establishing
a
concentration­
based
applicability
cut­
off
for
PCWP
process
units
by
comparing
emission
sources
covered
by
other
NESHAP
cited
by
AF&
PA
(
i.
e.,
those
with
concentration­
based
exemptions)
to
those
emission
sources
that
will
be
covered
by
the
PCWP
NESHAP.

III.
Evaluation
of
AF&
PA
Proposal
A.
Comparison
to
Emission
Sources
in
Rules
with
Applicability
Cut­
Offs
In
their
white
paper
and
comments
on
the
proposed
rule,
AF&
PA
listed
12
NESHAP
that
included
concentration­
based
applicability
cut­
offs.
Of
the
12
NESHAP,
4
weren't
relevant
because
the
cut­
offs
did
not
apply
to
process
vents
(
e.
g.,
equipment
leaks,
limitations
on
HAP
content
in
coatings).
The
remaining
8
NESHAP
were
petro­
chemical
sources
with
concentrationbased
cut­
offs
of
50
ppmv
(
or
in
some
cases,
20
ppmv).
These
8
NESHAP
include
the
hazardous
organic
NESHAP
(
HON)
(
40
CFR,
Part
63,
Subpart
G),
which
served
as
the
template
4
TABLE
3.
COMPARISON
OF
EMISSION
SOURCES6,7,8,9
Emission
stream
characteristic
Chemical
process
plant
sources
(
e.
g.,
HON,
MON,
pharmaceuticals)
PCWP
process
sources
No.
of
emission
points
per
plant
25
to
>
100
3
to
7
(
e.
g.,
2
dryers
and
1
press)

Typical
flowrates,
scfm
100
scfm
dryers:
30,000
scfm;
presses
60,000
scfm
Typical
HAP
concentrations,
ppmv
>>
1,000
ppmv
<
150
ppmv
for
similar
petro­
chemical
rules
that
came
later,
and
the
pharmaceuticals
NESHAP
(
40
CFR
Part
63,
Subpart
GGG).
We
focused
our
comparison
analyses
on
these
two
NESHAP
and
the
proposed
miscellaneous
organic
NESHAP
(
MON)
because
these
NESHAP
are
representative
of
the
8
petro­
chemical
NESHAP,
and
we
had
ready
access
to
the
project
data
bases
for
these
NESHAP.
Table
3
provides
a
comparison
between
the
emission
streams
associated
with
chemical
manufacturing
industries
and
those
associated
with
PCWP
plants.
As
shown
in
Table
3,
the
emissions
from
PCWP
process
units
are
typically
high
volume,
low
concentration
(
HVLC)
emission
streams.
Chemical
manufacturing
plants
such
as
those
covered
by
the
HON,
pharmaceutical
NESHAP,
MON,
and
other
similar
NESHAP,
typically
have
many
more
emission
points,
and
these
emission
points
(
process
vents)
have
significantly
lower
flow
rates
(
e.
g.,
100
standard
cubic
feet
per
minute
[
scfm])
and
significantly
higher
VOC/
HAP
concentrations
(
e.
g.,
>>
1,000
ppmv).
For
example,
approximately
63
percent
of
the
process
vents
in
the
HON
data
base
have
flow
rates
less
than
100
scfm,
and
90
percent
have
flow
rates
less
than
5,000
scfm.
6
The
typical
NESHAP
cut­
offs
established
for
chemical/
pharmaceutical
manufacturing
industries
are
process
vents
with
total
organic
carbon
(
TOC)
concentrations
less
than
50
ppmv,
or
flow
rates
less
than
0.005
cubic
meters
per
minute
(
0.17
scfm).
The
wood
products
industry
does
not
have
any
applicable
emission
sources
with
such
small
flow
rates.
For
example,
a
typical
wood
products
press
exhaust
flow
rate
would
be
about
60,000
scfm.
Also,
if
the
same
TOC
concentration
cut­
off
is
applied
to
both
a
low
and
a
high
flow
rate
stream,
the
higher
flow
rate
stream
will
have
a
higher
mass
emissions
(
ton/
yr),
so
concentration­
based
cut­
offs
are
generally
developed
for
lower
flow
rate
streams.
For
example,
the
pharmaceuticals
NESHAP
exempts
process
vents
with
HAP
concentrations
below
50
ppmv,
and
the
majority
of
these
emission
streams
(
i.
e.,
70
percent)
have
flow
rates

25
scfm,
and
none
are
above
2,500
scfm.
7
Those
process
vents
with
HAP
concentrations
below
50
ppmv
represent
about
40
percent
(
i.
e.,
878
vents)
of
the
approximately
2,224
process
vents
in
the
pharmaceuticals
NESHAP
data
for
which
concentration
data
were
available;
however,
these
exempted
vents
account
for
only
0.2
percent
of
the
total
HAP
emissions
from
the
2,224
process
vents.
The
estimated
average
HAP
emissions
from
these
exempted
pharmaceutical
process
vents
is
approximately
88
pounds
per
year
per
vent.
7
5
TABLE
4.
PCWP
INLET
(
UNCONTROLLED)
EMISSIONS
CONCENTRATION
DATA10
APCD
HAP
data
(
formaldehyde
+
methanol)
THC
data
(
for
comparison)

Total
No.
w/
HAP
data
No.
w/
inlet
<
50
ppmv
No.
w/
inlet
<
20
ppmv
Total
No.
w/
THC
data
No.
w/
inlet
<
50
ppmv
No.
w/
inlet
<
20
ppmv
RTO
14
11
4
16
0
0
RCO
2
2
1
3
1
0
BIO
2
1
0
3
0
0
TOTAL
18
14
5
22
1
0
As
shown
in
Table
3,
the
emissions
from
dryers
and
presses
at
wood
products
plants
are
not
comparable
to
the
emissions
from
process
vents
at
chemical/
pharmaceutical
manufacturing
plants
(
differences
in
number
of
emission
points
per
plant,
flowrates,
and
concentrations),
and
therefore,
it
may
not
be
appropriate
to
"
borrow"
concentration
cut­
offs
from
these
rules.

B.
Relationship
Between
Cut­
Off
and
MACT
Floor
Analysis
When
the
concentration­
based
applicability
cut­
off
was
included
in
the
HON,
the
assumption
was
that
none
of
the
vent
streams
at
that
level
(
e.
g.,
50
ppmv
concentration
or
lower)
would
be
subject
to
the
MACT
floor
(
i.
e.,
no
emission
controls
would
be
required
for
those
sources,
even
without
the
cut­
off).
Therefore,
we
analyzed
the
available
data
for
PCWP
emission
sources
to
determine
if
the
same
would
be
true
for
the
PCWP
NESHAP.
The
PCWP
MACT
floor
analysis
is
based
on
an
add­
on
control
device
that
can
reduce
HAP
emissions
by
at
least
90
percent.
2
The
majority
of
the
emissions
data
used
to
support
this
level
of
control
was
supplied
by
the
PCWP
industry
and
is
summarized
in
a
separate
memorandum.
10
Table
4
summarizes
the
available
HAP
and
total
hydrocarbon
(
THC)
concentration
data
measured
at
the
inlets
of
the
control
devices.
Data
were
available
for
three
different
types
of
add­
on
control
devices
capable
of
reducing
HAP
emissions
by
90
percent:
RTO,
regenerative
catalytic
oxidizers
(
RCO),
and
biofilters
(
BIO).
Emissions
data
were
not
available
for
all
of
the
HAP
emitted
from
all
of
the
tested
PCWP
sources
equipped
with
MACT
controls;
however
data
for
methanol
and
formaldehyde
were
available
for
the
majority
of
these
sources.
Therefore,
the
concentrations
of
methanol
and
formaldehyde
were
summed
to
approximate
the
total
HAP
concentration
(
these
two
pollutants
represent
approximately
80
percent
of
total
HAP
emissions
from
PCWP
sources).
As
shown
in
Table
4,
of
the
18
controlled
process
units
for
which
HAP
control
efficiency
data
are
available,
14
(
78
percent)
have
associated
uncontrolled
HAP
concentrations
<
50
ppmv.
Thus,
a
50
ppmv
cut­
off
does
not
represent
the
MACT
floor.
Five
of
the
18
controlled
process
units
(
i.
e.,
28
percent)
have
HAP
concentrations
<
20
ppmv;
so
a
20
ppmv
HAP
cut­
off
also
would
not
represent
the
MACT
floor.

A
review
of
emissions
data
collected
by
the
industry
shows
similar
results.
Table
5
summarizes
the
concentration
data
for
PCWP
sources
tested
by
the
National
Council
of
the
Paper
6
Industry
for
Air
and
Stream
Improvement
(
NCASI).
11,12,13,14,15,16
The
NCASI
data
set
represents
the
only
available
data
set
that
includes
emissions
data
for
all
six
of
the
HAP
listed
in
the
definition
of
"
total
HAP."
These
data
include
some
of
the
PCWP
process
units
with
MACT
controls
that
are
included
in
Table
4
as
well
as
uncontrolled
PCWP
process
units.
As
shown
in
Table
5,
72
percent
of
the
PCWP
process
units
tested
by
NCASI
have
uncontrolled
total
HAP
emissions
concentrations
below
50
ppmv,
and
79
percent
of
those
PCWP
units
already
equipped
with
MACT
controls
have
uncontrolled
total
HAP
emissions
concentrations
below
50
ppmv.
In
addition,
38
percent
of
the
PCWP
process
units
tested
by
NCASI
have
uncontrolled
total
HAP
emissions
below
20
ppmv,
and
36
percent
of
the
process
units
with
MACT
controls
have
uncontrolled
total
HAP
concentrations
below
20
ppmv.
Because
many
of
the
process
units
with
MACT
controls
have
uncontrolled
total
HAP
concentrations
less
than
50
ppmv
and
less
than
20
ppmv,
it
is
clear
that
these
concentration
cut­
offs
do
not
represent
the
MACT
floor
for
PCWP
process
units.

TABLE
5.
SUMMARY
OF
NCASI
DATA11,12,13,14,15,16
Process
unit
No.
of
units
tested
by
NCASI
No.
of
units
tested
w/
MACT
controls
Range
in
concentration
of
emissions
(
ppmv
total
for
6­
HAP)
(
average)
a
No.
of
units
with
uncontrolled
concentration
<
50
ppmv
No.
of
units
with
uncontrolled
concentration
<
20
ppmv
All
units
tested
Units
with
MACT
controls
All
units
tested
Units
with
MACT
controls
Primary
tube
dryer
4
0
9
to
134
ppmv
(
54
ppmv)
2
(
50%)
NAb
1
(
25%)
NAb
Presses
9
7
5
to
153
ppmv
(
49
ppmv)
5
(
55%)
5
(
71%)
3
(
33%)
3
(
43%)

OSB
dryer
3
3
22
to
114
ppmv
(
48
ppmv)
2
(
67%)
2
(
67%)
0
(
0%)
0
(
0%)

PB
dryer
(
green)
4
1
6
to
51
ppmv
(
30
ppmv)
3
(
75%)
1
(
100%)
1
(
25%)
1
(
100%)

Veneer
dryer
9
3
4
to
46
ppmv
(
20
ppmv)
9
(
100%)
3
(
100%)
6
(
67%)
1
(
33%)

TOTAL
29
14
4
to
153
ppmv
21
(
72%)
11
(
79%)
11
(
38%)
5
(
36%)

a
Six
HAP
are
acetaldehyde,
acrolein,
formaldehyde,
methanol,
phenol,
and
propionaldehyde.
b
NA
=
Not
applicable
because
no
units
equipped
with
MACT
controls
were
tested
by
NCASI.

C.
Relationship
Between
Cut­
Off
and
Low­
Level
Emission
Sources
When
setting
a
cut­
off
of
50
ppmv
in
the
development
of
other
NESHAP,
the
assumption
was
that
such
sources
had
only
minimal
emissions
that
were
below
levels
that
would
be
regulated
by
the
applicable
MACT
floor.
This
would
not
be
the
case
with
wood
products
plants
because
of
7
the
higher
flow
rates.
Table
6
shows
the
effect
of
higher
flow
rates
on
the
mass
emissions
of
HAP
at
the
same
concentration
(
50
ppmv).
As
shown
in
Table
6,
at
a
flow
rate
of
20,000
dscfm
(
a
typical
PCWP
dryer
flow
rate),
the
methanol
emissions
associated
with
a
50
ppmv
emission
stream
would
be
about
21
tons
per
year,
which
exceeds
the
threshold
for
a
major
source.
8
TABLE
6.
FLOW
RATE
VERSUS
MASS
EMISSIONS
FOR
50
PPMV
METHANOL
EMISSION
STREAM
Flowrate,
dscfm
Mass
emissions,
ton/
yr
20,000
21
50,000
50
100,000
103
Assumptions:
(
1)
50
ppmv
of
methanol
in
emission
stream;
(
2)
standard
conditions;
and
(
3)
source
operates
8,424
hours
per
year
Based
on
these
calculations,
inclusion
of
a
concentration­
based
applicability
cut­
off
would
allow
major
sources
of
emissions
to
go
uncontrolled.
Therefore,
a
50
ppmv
applicability
cut­
off
applied
to
PCWP
sources
would
not
correspond
to
a
low
level
of
emissions
that
would
not
be
regulated
by
the
MACT
floor.
Table
7
shows
the
typical
annual
HAP
emissions
from
PCWP
process
units
that
would
be
subject
to
emission
limits
in
the
PCWP
NESHAP.
These
data
further
demonstrate
that
a
50
ppmv
cut­
off
would
exempt
most
PCWP
process
units
and
many
major
sources
of
HAP
emissions
from
MACT
controls,
and
thus,
would
be
inconsistent
with
the
intent
and
effect
of
similar
cut­
offs
in
other
NESHAP.

TABLE
7.
TYPICAL
ANNUAL
HAP
EMISSIONS
FROM
PCWP
PROCESS
UNITS
Process
units
with
emission
limits
in
PCWP
rule
Would
a
significant
number
of
process
units
be
exempted
with
a
50
ppmv
HAP
cut­
off?
a
Typical
total
HAP
emissions
from
individual
process
units
(
ton/
yr)
b
(
1)
Fiberboard
mat
dryer
heated
zones
(
at
new
affected
sources
only)
yes
9
(
2)
Green
rotary
dryers
yes
11
(
3)
Hardboard
ovens
yes
18
(
4)
Press
predryers
(
at
new
affected
sources
only)
(
no
data)
15
(
5)
Pressurized
refiners
no
21
(
6)
Tube
dryers
yes
65
(
MDF),
60
(
HB)

(
7)
Reconstituted
wood
product
board
coolers
(
at
new
affected
sources
only)
yes
5
(
PB),
3
(
MDF)

(
8)
Reconstituted
wood
product
presses
yes
37
(
PB),
76
(
OSB),
38
(
MDF),
23
(
HB)

(
9)
Softwood
veneer
dryer
heated
zones
yes
5
(
10)
Strand
dryers
yes
32
Process
units
with
emission
limits
in
PCWP
rule
Would
a
significant
number
of
process
units
be
exempted
with
a
50
ppmv
HAP
cut­
off?
a
Typical
total
HAP
emissions
from
individual
process
units
(
ton/
yr)
b
9
a
Based
on
a
review
of
the
range
of
available
HAP
concentration
data.
b
Based
on
typical
ton/
yr
documented
in
BID.
17
D.
Other
Issues
1.
Compliance
issues.
Given
the
fact
that
most
PCWP
process
units
have
uncontrolled
HAP
concentrations
between
20
and
50
ppmv
and
that
the
emissions
vary
over
time
for
a
given
process
unit
(
not
to
mention
among
similar
process
units),
setting
and
enforcing
cut­
offs
in
this
range
would
be
very
difficult,
notwithstanding
the
MACT
floor
issue.
Any
change
in
wood
species,
increase
in
operating
temperature,
reformulation
of
resin,
etc,
could
push
a
process
unit
over
or
under
the
concentration
limit.
Even
with
no
changes
in
raw
material
or
operating
conditions,
sources
would
be
continually
cycling
above
and
below
the
cut­
off
due
to
the
inherent
variability
in
emissions
and
the
fact
that
most
sources
have
emissions
in
the
ranges
being
suggested
as
cut­
offs.

2.
Dilution
issues.
The
emission
sources
at
wood
products
plants
are
diluted
sources
under
normal
operating
conditions,
and
therefore,
the
requirement
in
other
rules
that
the
emissions
sources
complying
with
the
cut­
offs
be
"
undiluted
and
uncontrolled"
(
to
ensure
that
the
standards
are
not
circumvented
via
dilution)
could
not
be
met
for
wood
product
sources.
The
measured
oxygen
levels
from
many
wood
products
sources
are
at
ambient
levels
under
normal
operating
conditions.
This
means
a
facility
could
double
or
triple
the
amount
of
air
added
to
the
emission
stream
and
still
have
the
same
measured
oxygen
concentration,
thus
making
it
impossible
to
determine
if
"
excessive"
dilution
has
occurred.
The
reason
these
emission
streams
are
diluted
is
that
air
is
used
to
transport
the
wood
fiber
through
the
dryers
(
e.
g.,
tube
dryers
and
rotary
dryers)
as
well
as
to
dry
the
fibers.
Air
also
may
be
added
between
the
burner
exhaust
and
the
dryer
inlet
to
cool
the
hot
exhaust
to
the
desired
temperature
before
it
enters
the
dryer.
The
ratio
of
added
air
to
the
total
flow
through
the
dryer
is
highly
variable
and
is
affected
by
the
burner
type,
fuel,
and
dryer
system.
18
Note
that
operators
control
the
amount
of
air
that
is
added
to
the
dryers,
and
the
industry
likely
would
not
want
the
rule
to
take
away
that
flexibility.
In
their
white
paper,
AF&
PA
suggested
that
the
dilution
issue
could
be
addressed
by
having
facilities
accept
federally
enforceable
permit
limits
on
their
exhaust
flow
rates.
4
However,
this
would
not
address
the
fact
that
the
streams
are
already
dilute
under
normal
operation
conditions.
Also
PCWP
facilities
would
likely
want
to
set
the
permit
limit
at
the
maximum
flow
rate,
which
would
equate
to
further
dilution
at
normal
production
rates.

Although
Table
1
provides
three
concentration­
based
options
for
complying
with
the
PCWP
NESHAP
as
alternatives
to
a
90
percent
reduction
in
emissions
(
i.
e.,
achieve
20
ppmv
THC,
1
ppmv
methanol,
or
1
ppmv
formaldehyde
in
the
outlet
of
the
control
device),
these
three
concentration­
based
options
only
apply
to
sources
that
are
equipped
with
add­
on
control
systems.
Generally,
concentration­
based
emission
limits
at
the
outlet
of
a
control
device
are
expressed
in
terms
of
a
percent
oxygen
level,
so
that
emissions
can
be
normalized
and
dilution
effects
accounted
10
for.
The
concentration­
based
emission
limits
in
Table
1
do
not
include
a
percent
oxygen
basis
because
the
dilute
nature
of
the
emission
streams
entering
these
devices
would
cause
the
oxygen
correction
equation
to
go
to
zero
in
the
denominator.
For
sources
equipped
with
add­
on
controls,
this
is
not
perceived
as
a
significant
issue
because
sources
equipped
with
add­
on
controls
would
not
be
expected
to
further
dilute
the
emission
streams
being
treated
because
in
doing
so
they
would
increase
their
control
device
capital
and
operating
costs.

IV.
Conclusion
When
establishing
applicability
cut­
offs
for
NESHAP,
EPA
must
evaluate
these
cut­
offs
in
concert
with
the
MACT
floor
analysis.
To
support
the
inclusion
of
a
50
ppmv
cut­
off
or
an
alternative
cut­
off,
EPA
would
have
to
clearly
demonstrate
that
the
cut­
off
levels
do
not
exempt
emission
volumes
that
should
be
caught
by
the
MACT
floor.
The
50
ppmv
concentration­
based
applicability
cut­
off
proposed
by
AF&
PA
does
not
meet
this
criterion
because
it
would
exempt
many
process
units
that
would
be
subject
to
MACT
floor
controls.
In
fact,
a
50
ppmv
cut­
off
would
exempt
the
majority
of
process
units
in
the
PCWP
industry
from
regulation,
despite
the
fact
that
many
of
these
process
units
are
major
sources
of
HAP
emissions
at
PCWP
facilities.
In
addition,
the
process
vent
characteristics
(
e.
g.,
combination
of
concentration
and
flow
rate)
for
PCWP
facilities
are
dissimilar
to
process
vents
regulated
by
the
NESHAP
cited
by
AF&
PA
as
precedents
for
the
concentration­
based
applicability
exemption.
For
these
reasons,
and
the
reasons
discussed
in
Section
III.
D,
we
recommend
against
including
a
concentration­
based
applicability
cut­
off
in
the
PCWP
NESHAP.

V.
References
1.
Federal
Register.
Volume
68,
Number
6.
Page
1276­
1339.
January
9,
2003.
National
Emission
Standards
for
Hazardous
Air
Pollutants:
Plywood
and
Composite
Wood
Products;
Proposed
Rule.

2.
Memorandum
from
B.
Nicholson
and
K.
Hanks,
MRI,
to
M.
Kissell,
EPA/
ESD.
July
13,
2000
(
Revised
June
7,
2002).
Determination
of
MACT
floors
and
MACT
for
the
Plywood
and
Composite
Wood
Products
Industry.

3.
Memorandum
from
K.
Hanks,
MRI,
to
M.
Kissell,
EPA/
ESD.
June
2,
2000
(
Revised
June
26,
2002).
Development
of
Production­
Based
Emission
Limits
of
Plywood
and
Composite
Wood
Products
Process
Units.

4.
Letter
and
attachments
from
S.
Kneiss,
AF&
PA,
to
J.
Holmstead,
EPA/
OAR.
December
21,
2001.
AF&
PA
White
Paper
on
Concentration­
Based
DeMinimis
Applicability
Exemptions
in
the
Wood
Products
MACT.

5.
Letter
and
attachments
from
T.
Hunt,
AF&
PA,
to
EPA
Docket
No.
A­
98­
44.
March
7,
2003.
Comments
on
Proposed
Plywood
and
Composite
Wood
Products
MACT.
11
6.
Memorandum
from
B.
Ferrero
and
T.
Olsen,
Radian,
to
S.
Milliken,
EPA/
SDB.
June
17,
1992.
HON
Process
Vents
Flow
Rate
and
Concentration
Limits.
EPA
Docket
No.
A­
90­
19.
Docket
Item
No.
II­
B­
272.

7.
Data
Base
Used
to
Support
the
Pharmaceutical
Manufacturing
NESHAP
(
40
CFR,
Part
63,
Subpart
GGG).
Process
Vents
Data
Base.

8.
Memorandum
from
D.
Bullock,
K.
Hanks,
and
B.
Nicholson,
MRI
to
M.
Kissell,
EPA/
ESD.
April
28,
2000.
Summary
of
Responses
to
the
1998
EPA
Information
Collection
Request
(
MACT
Survey)
­­
General
Survey.

9.
Data
Base
Used
to
Support
the
Miscellaneous
Organic
Chemicals
Manufacturing
NESHAP
(
40
CFR,
Part
63,
Subpart
FFFF).
Process
Vents
Data
Base.

10.
Memorandum
from
R.
Nicholson,
MRI,
to
M.
Kissell,
EPA/
ESD.
May
26,
2000.
Control
Device
Efficiency
Data
for
Add­
on
Control
Devices
at
PCWP
Plants.

11.
Volatile
Organic
Compound
Emissions
From
Wood
Products
Manufacturing
Facilities,
Part
I
­
Plywood,
Technical
Bulletin
No.
768,
National
Council
of
the
Paper
Industry
for
Air
and
Stream
Improvement,
Inc.,
Research
Triangle
Park,
NC,
1999.

12.
Volatile
Organic
Compound
Emissions
From
Wood
Products
Manufacturing
Facilities,
Part
III
­
Medium
Density
Fiberboard,
Technical
Bulletin
No.
770,
National
Council
of
the
Paper
Industry
for
Air
and
Stream
Improvement,
Inc.,
Research
Triangle
Park,
NC,
1999.

13.
Volatile
Organic
Compound
Emissions
From
Wood
Products
Manufacturing
Facilities,
Part
IV
­
Particleboard,
Technical
Bulletin
No.
771,
National
Council
of
the
Paper
Industry
for
Air
and
Stream
Improvement,
Inc.,
Research
Triangle
Park,
NC,
1999.

14.
Volatile
Organic
Compound
Emissions
From
Wood
Products
Manufacturing
Facilities,
Part
V
­
Oriented
Strandboard,
Technical
Bulletin
No.
772,
National
Council
of
the
Paper
Industry
for
Air
and
Stream
Improvement,
Inc.,
Research
Triangle
Park,
NC,
1999.

15.
Volatile
Organic
Compound
Emissions
From
Wood
Products
Manufacturing
Facilities,
Part
VI
­
Hardboard/
Fiberboard,
Technical
Bulletin
No.
773,
National
Council
of
the
Paper
Industry
for
Air
and
Stream
Improvement,
Inc.,
Research
Triangle
Park,
NC,
1999.

16.
Memorandum
from
D.
Bullock,
MRI,
to
M.
Kissell,
EPA/
ESD/
WCPG.
November
3,
1999.
Approach
to
Using
Values
Below
Test
Method
Detection
Limits
in
the
Development
of
Emission
Factors
and
Control
Efficiencies.

17.
U.
S.
EPA.
Background
Information
Document
for
Plywood
and
Composite
Wood
Products
NESHAP.
Office
of
Air
Quality
Planning
and
Standards,
Research
Triangle
Park,
NC
27711.
September,
2000.
12
18.
R.
Nicholson,
MRI,
to
D.
Word,
NCASI.
February
17,
2000
(
Confirmed
via
Email
on
9/
7/
00).
Contact
report
to
(
1)
find
out
if
oxygen
measurement
data
were
available
from
the
NCASI
MACT
emissions
test
program,
and
(
2)
to
get
some
information
on
typical
oxygen
concentrations
in
dryer
and
press
exhaust
at
plywood
and
composite
wood
products
plants.

19.
"
EcoDRY:
The
Almost
Emission­
Free
Drying
of
Woodchips,
OSB
Flakes,
and
the
Like,"
by
Swiss
Combi.
Paper
distributed
at
AF&
PA
Wood
Products
MACT
Workshop.
March
13­
14,
2001.
Raleigh,
NC.

20.
Memorandum
from
K.
Hanks,
RTI,
to
Project
File.
August
26,
2002.
Information
on
American
Purification
Regenerative
Adsorption
Technology.
