2­
115
Fourth,
the
commenter
stated
that
using
add­
on
controls
to
comply
with
PBCO
will
benefit
facilities
that
have
process
units
that
emit
low
levels
of
HAP.
According
to
the
commenter,
several
companies
have
already
implemented
P2
strategies
that
have
been
established
as
BACT
in
a
PSD
permit.
Because
these
P2
strategies
may
fall
short
of
the
PBCO
limits,

companies
implementing
these
strategies
would
be
unable
to
achieve
compliance
with
the
proposed
rule
without
abandoning
the
P2
strategy
and
installing
full
control.

Fifth,
incorporating
add­
on
controls
in
the
PBCO
provides
incentive
to
find
low
energy
pollution
control
equipment.
The
commenter
gave
an
example
whereby
part
of
the
emission
unit
exhaust
could
be
used
as
combustion
air
for
an
onsite
boiler.
The
commenter
noted
that
in
most
cases,
the
boiler
could
only
handle
a
portion
of
the
exhaust
from
multiple
dryer
stacks.
The
commenter
stated
that
by
combining
this
type
of
partial
control
approach
with
low
temperature
drying,
a
facility
may
be
able
to
meet
the
applicable
dryer
PBCO
limit.
In
this
case,
allowing
for
partial
control
would
exclude
the
need
for
RTO
technology
and
would
provide
a
net
benefit
to
the
environment
with
a
reduction
of
collateral
oxidizer
emissions.
The
commenter
gave
another
example
in
which
a
facility
with
a
conveyor
dryer
could
send
the
exhaust
from
the
first
dryer
section
to
a
burner
and
then
send
the
heat
back
to
the
dryer;
the
emissions
from
the
remaining
dryer
sections
would
be
uncontrolled
if
the
total
emissions
were
below
the
PBCO
limit.
In
a
third
example
provided
by
the
commenter,
a
facility
would
remove
enough
HAP
to
comply
with
the
PBCO
limit
using
a
scrubber,
which
would
require
less
energy
than
incineration.
The
commenter
noted
EPA's
concern
that
facilities
could
operate
partial
control
options
at
levels
lower
than
than
a
MACT
control
level
and
agreed
that
"
any
add
on
control
device
used
to
make
up
a
shortcoming
with
a
PBCO
limit
would
be
operated
at
a
level
consistent
with
good
air
pollution
control
practices."

Response:
Like
the
proposed
rule,
the
final
rule
does
not
allow
sources
to
comply
with
the
PBCO
through
the
use
of
add­
on
control
systems.
Our
intention
for
including
the
PBCO
was
to
provide
an
alternative
to
add­
on
controls
(
e.
g.,
allow
for
and
encourage
the
exploration
of
pollution
prevention,
which
currently
has
not
been
demonstrated
as
achieved
by
PCWP
sources)

and
not
to
create
another
compliance
option
for
sources
equipped
with
add­
on
control
systems
that
could
inadvertently
allow
add­
on
control
equipped
systems
to
no
perform
to
expected
control
efficiencies.
Sources
equipped
with
add­
on
control
systems
already
have
six
different
compliance
2­
116
options
from
which
to
choose,
in
addition
to
the
emissions
averaging
compliance
option.
We
note
that
the
six
options
for
add­
on
control
systems
are
based
on
emission
reductions
achievable
with
MACT
control
devices
and
thus
are
a
measure
of
the
performance
of
MACT
control
devices.

This
might
not
be
true
if
a
source
combined
PBCO
and
add­
on
controls,
as
explained
below.

Table
2­
3
compares
the
PBCO
limits
included
in
the
proposed
rule
with
the
emission
levels
achieved
using
control
devices.
As
shown
in
Table
2­
3,
we
did
not
have
total
HAP
data
for
all
process
unit
groups
equipped
with
controls.
The
lack
of
total
HAP
data
for
process
units
equipped
with
controls
was
one
of
the
primary
reasons
we
chose
to
develop
the
six
add­
on
control
systems
options
in
the
proposed
format
(
i.
e.,
can
measure
THC,
methanol,
or
formaldehyde
instead
of
measuring
total
HAP).
However,
we
recognized
that
the
format
of
the
add­
on
control
system
compliance
options
would
preclude
P2
techniques,
and
thus,
we
needed
additional
compliance
options
that
could
be
met
without
the
installation
of
add­
on
controls
in
order
to
accommodate
development
of
P2
techniques.
One
approach
we
considered
was
to
review
the
available
total
HAP
data
for
facilities
equipped
with
controls
and
then
choose
a
representative
data
point
for
each
process
unit
group;
however,
we
had
to
discard
this
approach
because
controlled
total
HAP
data
are
not
available
for
half
of
the
process
unit
groups.
We
developed
a
number
of
other
approaches
to
establishing
PBCO
limits,
and
then
compared
the
results
of
these
approaches,
where
possible,
with
actual
emissions
in
the
outlet
of
control
devices.
9,23
The
approach
that
yielded
results
closest
to
actual
emissions
in
the
control
device
outlets
was
an
approach
based
on
a
90
percent
reduction
from
the
average
emissions
within
each
process
unit
group.
Thus,
this
approach
was
the
one
that
resulted
in
limits
that
would
most
closely
represent
an
alternative
to
the
six
compliance
options
for
add­
on
control
systems.

However,
our
intention
was
not
to
develop
an
alternative
limit
to
the
six
limits
already
established
for
add­
on
control
devices.
Our
intention
was
to
develop
an
alternative
for
P2
techniques.
We
decided
to
select
an
approach
that
allows
sources
that
develop
P2
techniques
(
or
are
otherwise
inherently
low­
emitting
sources)
to
comply
and
that
reduces
HAP
emissions
without
generating
the
NOx
emissions
associated
with
incineration­
based
controls.
As
a
result,
we
selected
a
90
percent
reduction
from
the
highest
data
point
within
each
process
unit
group,
because
the
results
appeared
to
be
at
levels
that
would
not
preclude
the
development
of
environmentally
beneficial
P2
options
as
MACT.
2­
117
Table
2­
3.
Comparison
of
PBCO
with
Emissions
from
Outlet
of
Control
Devices
Process
unit
group
Proposed
PBCO
limita
Units
Total
HAP
(
6
HAP)
measurements
from
outlet
of
controlled
units
Ratio
of
PBCO
to
Total
HAP
in
outlet
of
controls
Fiber
board
mat
dryers
0.022
lb/
MSF
1/
2"
No
data
­­

Green
rotary
dryers
0.058
lb/
ODTb
0.0086
6.7
Hardboard
ovens
0.022
lb/
MSF
1/
8"
0.0049
4.5
Press
predryers
0.037
lb/
MSF
1/
2"
No
data
­­

Pressurized
refiners
0.039
lb/
ODT
No
data
­­

Tube
dryers
0.26
lb/
ODT
No
data
­­

Reconstituted
wood
product
board
coolers
0.015
lb/
MSF
3/
4"
No
data
­­

Reconstituted
wood
products
presses
0.3
lb/
MSF
3/
4"
0.23;
0.16;
0.079;
0.061;
0.056;
0.022
1.3
to
151
Softwood
veneer
dryers
0.022
lb/
MSF
3/
8"
0.015;
0.011;
0.11c
0.2c
to
2
Strand
dryers
0.18
lb/
ODT
0.081;
0.055;
0.44d
2.2
to
3.3
a
PBCO
limits
are
based
on
a
90
percent
reduction
applied
to
the
highest
available
6­
HAP
test.
b
ODT
=
oven­
dried
ton,
MSF
=
thousand
square
feet
at
thickness
specified
c
Data
point
is
for
an
RCO
that
achieved
<
50
percent
control
of
HAP
during
testing,
although
THC
control
efficiency
was
90
percent.
d
Data
for
this
unit
were
discarded
during
MACT
floor
determinations
because
unit
was
operating
below
its
permitted
control
efficiency.

The
text
quoted
by
commenter
IV­
D­
27
from
the
PBCO
memo
was
misinterpreted
by
the
commenter;
candidate
PBCO
limits
were
only
compared
to
HAP
emissions
at
the
outlet
of
control
devices
as
a
way
of
gauging
their
appropriateness
as
applicability
cutoffs.
9
As
shown
in
Table
2­

3,
the
resultant
PBCO
limits
are
higher
than
the
HAP
emission
levels
measured
in
the
outlet
of
the
MACT
control
devices,
and
in
some
cases,
significantly
higher.
Thus,
the
PBCO
limits
are
not
an
appropriate
alternative
for
sources
equipped
with
add­
on
controls.
If
PBCO
were
allowed
as
another
option
for
measuring
the
performance
of
add­
on
control
devices,
operators
could
run
the
APCD
so
that
the
APCD
would
not
achieve
MACT
level
emissions
reductions,
but
would
meet
the
PBCO.
We
note
that
we
did
not
develop
the
methanol
and
formaldehyde
add­
on
control
options
(
options
4
and
6
in
Table
1B
of
the
proposed
rule)
based
on
typical
or
maximum
levels
of
2­
118
methanol
and
formaldehyde
found
in
the
outlet
of
the
control
devices,
but
instead
looked
at
the
performance
of
the
control
devices
in
reducing
these
HAP,
set
the
levels
based
on
the
method
detection
limits
for
these
compounds,
and
included
a
minimum
inlet
concentration
requirement
for
the
use
of
the
outlet
concentration
options
to
ensure
that
MACT­
level
HAP
emissions
reductions
are
achieved.
Allowing
the
use
of
APCD
to
comply
with
PBCO
could
allow
cirumvention
of
such
optimization,
which
could
render
the
MACT
control
itself
to
be
less
effective
than
MACT.
We
also
note
that,
in
comments
elsewhere
in
this
document
(
see
comment
No.
2.3.2.2),
the
commenters
contended
that
the
CAA
intended
for
EPA
to
focus
on
emission
reductions
as
opposed
to
emission
levels.

Regarding
the
other
MACT
standards
referenced
by
the
commenters,
we
agree
that
these
other
rules
may
allow
facilities
more
flexibility
in
meeting
a
production­
based
option
(
e.
g.,

"
lb/
ton"
emission
limit);
however,
as
stated
previously
we
cannot
allow
add­
on
controls
to
be
used
to
meet
the
PBCO
in
the
PCWP
rule
because
doing
so
would
render
these
limits
not
equivalent
to
the
other
compliance
options
(
see
also
response
to
comment
No.
2.6.4.6
and
Table
2­
3
for
a
comparison
of
emissions
reductions
achieved
using
different
compliance
options.)
Also,

we
note
that,
although
the
MACT
rules
cited
by
the
commenters
do
not
place
restrictions
on
the
use
of
the
"
lb/
ton"
limits,
these
other
rules
do
not
contain
the
multitude
of
compliance
options
found
in
the
PCWP
rule
and
they
do
not
allow
multiple
compliance
options
to
be
used
on
the
same
process
unit
at
the
same
time,
which
is
consistent
with
the
PCWP
rule.
For
example,
the
Paper
and
Other
Web
Coating
NESHAP
states
that:
"
You
may
use
different
compliance
options
for
different
web
coating/
printing
operations
or
at
different
times
on
the
same
web
coating/
printing
operation.
However,
you
may
not
use
different
compliance
options
at
the
same
time
on
the
same
web
coating/
printing
operation."
As
explained
previously
in
the
response
to
comment
No.
2.6.1.1,
a
PCWP
facility
may
use
any
number
of
options,
as
long
as
these
options
are
not
combined
for
an
individual
process
unit
(
i.
e.,
can
meet
PBCO
for
one
dryer,
control
emissions
from
a
blender
to
avoid
controlling
emissions
on
the
remaining
two
dryers
as
part
of
an
emissions
average,
and
use
an
add­
on
control
device
for
the
press.)

Regarding
the
examples
cited
by
the
commenter
as
candidates
for
a
PBCO
if
add­
on
controls
were
allowed,
we
note
that
the
final
rule
includes
a
revised
MACT
floor
for
existing
conveyor
dryers,
such
that
existing
conveyor
dryers
that
send
the
emissions
from
the
first
section
2­
119
back
to
the
burner
should
be
able
to
meet
the
rule
requirements
without
additional
controls.
We
also
note
that
"
partial
control"
(
e.
g.,
routing
part
of
the
emission
stream
from
a
process
unit
to
an
onsite
boiler
for
incineration)
is
already
allowed
as
part
of
an
emissions
averaging
plan
as
long
as
the
actual
emission
reductions
achieved
are
greater
than
or
equal
to
the
required
emission
reductions.
(
See
also
response
to
comment
No.
2.6.4.6.)
We
further
note
that,
when
partial
control
is
used
as
part
of
an
emissions
averaging
plan,
the
overall
reductions
are
equivalent
to
what
would
be
achieved
if
a
source
elected
to
comply
using
the
add­
on
control
system
compliance
options;
however,
the
same
would
not
be
true
if
partial
control
were
used
to
comply
with
a
PBCO
limit.
Regarding
the
use
of
scrubbers
to
comply
with
a
PBCO,
as
stated
in
our
response
to
comment
No.
2.5.2.2,
the
industry's
own
data
do
not
support
wet
scrubbers
as
a
reliable
control
technology
for
HAP,
and
sources
equipped
with
wet
control
devices
will
be
required
to
test
prior
to
the
wet
control
device
if
they
elect
to
comply
with
a
PBCO.

2.6.3.3
Comment:
Commenters
IV­
D­
19,
IV­
D­
27,
and
IV­
D­
56
agreed
that
choosing
a
90
percent
reduction
from
the
highest
emission
test
in
each
source
category
is
the
proper
method
for
developing
PBCO
limits,
but
argued
that
statistical
methods
should
be
used
to
establish
a
realistic
estimate
of
the
highest
emission
test.
Commenters
IV­
D­
28
and
IV­
D­
43
concurred.

Commenter
IV­
D­
27
noted
that
in
section
III.
F.
1
of
the
preamble,
EPA
states
that
"
the
available
total
HAP
test
data
sets
are
too
small
to
justify
use
of
such
statistical
methods,
and
the
resulting
compliance
options,
in
many
cases,
seemed
unreasonably
high
compared
to
the
actual
emissions
from
process
units
with
MACT
control
systems.
Therefore,
statistical
methods
were
not
used."

Commenters
IV­
D­
27
and
IV­
D­
56
disagreed
with
EPA's
conclusion
that
statistical
methods
should
not
be
used
and
stated
that,
due
to
the
relatively
small
data
set
available
for
establishing
PBCO
limits,
it
is
unlikely
that
the
PBCO
limits
are
based
on
the
highest
emitting
source.
The
commenters
noted
that,
although
the
database
used
to
establish
the
PBCO
limits
is
one
of
the
most
comprehensive
efforts
of
this
type
ever
attempted,
it
is
necessarily
limited
by
scope,
cost,

and
design.
The
commenters
contended
that
choosing
the
maximum
observed
value
from
this
database
as
the
basis
for
determining
the
population
maximum
results
in
an
underestimate
of
the
actual
highest
value
and
inappropriately
low
limits
for
the
PBCO.
Commenter
IV­
D­
27
added
that
any
source
with
emissions
above
the
highest
level
found
in
the
database
would
have
to
reduce
2­
120
emissions
much
more
than
90
percent
to
comply
with
PBCO
limits,
which
is
"
illogical"
and
"
unfair."

Commenter
IV­
D­
27
acknowledged
that,
for
some
process
groups,
there
is
insufficient
information
to
justify
applying
statistics,
but
argued
that,
for
reconstituted
wood
product
presses,

softwood
veneer
dryers,
and
tube
dryers,
there
is
enough
information.
The
commenter
suggested
that
EPA
use
regression
analyses
to
determine
a
minimum
data
requirement
for
applying
statistical
methods.
According
to
the
commenter,
the
first
step
would
be
to
calculate
a
more
accurate
estimate
of
the
true
population
maximum
for
each
source
type
using
a
95
percent
statistical
confidence
level
that
99
percent
of
the
population
is
enclosed
in
the
estimate.
The
commenter
stated
that
when
this
number
is
multiplied
by
0.1,
the
result
will
more
realistically
represent
90
percent
control
of
the
true
population
maximum.
(
The
commenter
referred
to
an
issue
paper
the
commenter
had
previously
submitted
to
EPA
for
more
details
on
the
methodology
[
Docket
Item
#

II­
D­
521].)
In
the
second
step
recommended
by
the
commenter,
EPA
would
determine
the
percentage
change
in
the
PBCO
from
the
original
limits
to
the
limits
determined
by
statistics
and
plot
the
sample
size
against
that
percentage
change.
Using
a
power
curve
regression
on
this
plot,

the
commenter
concluded
that
a
minimum
sample
size
should
be
eight.
According
to
the
commenter,
the
adjusted
PBCO
for
reconstituted
wood
product
presses
would
be
0.39
lb/
MSF
3/
4;
for
softwood
veneer
dryers,
it
would
be
0.36
lb/
MSF
3/
8;
and
for
tube
dryers
it
would
be
0.45
lb/
oven­
dried
ton
(
ODT).
The
commenter
asserted
that
the
revised
PBCO
limits
are
within
the
realm
of
values
considered
by
EPA
when
developing
the
PBCO;
the
commenter
noted
that
the
memo
Development
of
Production­
Based
Emission
Limits
for
Plywood
and
Composite
Wood
Products
Process
Units
(
Docket
#
II­
B­
32)
makes
high­
end
estimates
of
0.37
lb/
MSF
3/
4
for
reconstituted
wood
products
presses
and
0.33
lb/
MSF
3/
8
for
softwood
veneer
dryers.

For
the
process
unit
groups
that
do
not
have
sufficient
data
points,
the
commenter
recommended
that
EPA
incorporate
the
basic
findings
of
the
statistical
analysis
and
apply
a
30
percent
increase
to
the
PBCO
limits
across
the
board.
The
commenter
stated
that
the
30
percent
factor
is
similar
to
that
recommended
for
the
reconstituted
wood
products
presses,
the
process
unit
group
with
the
largest
data
set.
Application
of
the
30
percent
increase
to
the
other
data
sets
is
based
on
a
assumption
that
the
distribution
of
emissions
data
from
the
largest
available
data
set
is
similar
to
the
distribution
that
would
be
observed
in
other
categories
if
a
sufficient
number
of
2­
121
samples
were
available.
The
commenter
contended
that,
at
a
minimum,
a
statistical
analysis
should
be
applied
to
the
three
process
groups
with
at
least
8
samples.
The
commenter
stated
that
revising
the
PBCO
limits
would
encourage
more
facilities
to
pursue
pollution
prevention
options,

enhancing
technological
progress
in
that
area,
and
it
would
lower
the
cost
of
MACT
implementation
while
reducing
collateral
emissions.
The
commenter
asserted
that
more
facilities
would
be
able
to
ensure
compliance
100
percent
of
the
time
and
would
be
encouraged
to
use
the
PBCO
if
the
limits
were
less
stringent.

Response:
We
disagree
with
the
commenters'
recommended
changes
to
the
PBCO.

When
we
developed
the
PBCO,
we
looked
at
a
number
of
options
for
establishing
the
PBCO
limits,
including
several
recommendations
from
the
industry,
some
of
which
included
statistical
analyses
and
some
of
which
did
not.
We
documented
the
results
that
would
be
obtained
using
each
of
these
potential
approaches
and
compared
these
results
to
the
total
HAP
emissions
measured
at
the
outlet
of
control
devices.
9
As
discussed
in
the
response
to
the
previous
comment,

we
selected
an
approach
that
was
close
to
the
emission
levels
in
the
outlet
of
the
control
because
we
believed
that
it
would
be
appropriate
to
allow
this
alternative
if
environmentally
beneficial
P2
techniques
were
used
to
comply.
The
approach
that
met
this
criterion
was
a
90
percent
reduction
from
the
highest
total
HAP
data
point.
The
commenter's
assertion
that
the
data
set
may
not
include
the
highest­
emitting
source
may
be
true.
However,
we
note
that
elsewhere
in
their
comments
(
see
comment
No.
2.6.2.2)
the
same
commenter
(
IV­
D­
27)
stated
that
"
the
data
used
to
establish
the
floor
only
included
operations
at
maximum
capacity
and
did
not
reflect
the
full
operating
range
of
the
process,"
which
would
imply
that
testing
under
more
typical
conditions
would
have
yielded
lower
emissions
from
the
process
units
tested.
Regardless,
as
explained
in
the
response
to
the
previous
comment,
using
the
highest
emitting
source
to
set
the
PBCO
limits
was
simply
a
starting
point;
the
"
test"
we
used
to
determine
if
the
PBCO
limits
were
appropriate
was
to
compare
the
resulting
PBCO
limits
to
the
outlet
emissions
from
control
devices.
Therefore,
the
fact
that
there
could
be
higher­
emitting
sources
is
immaterial
for
the
purpose
of
setting
the
PBCO
limits.
The
same
is
true
regarding
the
use
of
statistics;
that
is,
the
outcome
of
the
statistical
analyses
were
inconsistent
with
the
outlet
emissions
from
control
devices,
and
therefore,
we
did
not
incorporate
statistics
into
the
development
of
the
PBCO.
We
also
maintain
that,
regardless
of
the
outcome,
the
use
of
statistics
is
inappropriate
given
the
limitations
of
the
data
set.
Regarding
2­
122
the
comment
that
high­
emitting
sources
would
have
to
reduce
emissions
by
more
than
90
percent,

we
note
that
(
1)
the
PBCO
limits
were
not
developed
for
high­
emitting
sources
or
for
sources
that
use
add­
on
control
devices,
but
instead
were
developed
to
provide
a
compliance
option
for
inherently
low­
emitting
sources;
and
(
2)
if
a
high­
emitting
source
uses
a
control
device,
then
that
source
only
has
to
reduce
emissions
by
90
percent,
not
more
than
90
percent.

Finally,
we
note
that
the
emissions
from
PCWP
process
units
are
not
insignificant,
even
when
these
units
operate
at
the
PBCO
thresholds.
For
example,
a
single
wood
products
press
that
operates
at
the
applicable
PBCO
limit
(
0.30
lb/
MSF
3/
4")
still
emits
15
tons
of
HAP
per
year,

and
a
single
strand
dryer
operating
at
the
applicable
PBCO
limit
(
0.18
lb/
ODT)
emits
6
tons
of
HAP
per
year.
Also,
raising
the
PBCO
limits
to
levels
recommended
by
the
commenters
would
be
inconsistent
with
the
MACT
floor.
For
example,
the
commenters
recommend
that
the
PBCO
limit
for
softwood
veneer
dryers
be
increased
from
the
proposed
0.022
lb/
MSF
3/
8"
to
0.36
lb/
MSF
3/
8";
however,
all
of
the
softwood
plywood
dryers
equipped
with
MACT
controls
that
were
tested
by
industry
have
uncontrolled
emissions
less
than
0.36
lb/
MSF
3/
8".
Thus,
if
we
were
to
raise
the
limits
as
suggested,
sources
already
equipped
with
controls
would
not
be
required
to
keep
those
controls
in
place
to
comply
with
the
PCWP
rule,
such
that,
not
only
would
the
required
MACT
emission
reductions
not
be
met,
but
there
could
also
be
a
net
increase
in
HAP
emissions.

2.6.4
Emissions
averaging
2.6.4.1
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
expressed
support
for
inclusion
of
an
emissions
averaging
program
in
the
proposed
rule.
Commenters
IV­
D­
21
and
IV­
D­
28
specifically
supported
the
following
four
elements
in
the
emissions
averaging
plan:
(
1)
allowing
sources
to
control
other
waste
streams
in
lieu
of
those
specifically
subject
to
MACT;
(
2)
not
requiring
a
discount
factor
for
sources
using
emissions
averaging;
(
3)
not
limiting
the
number
or
type
of
emissions
points
that
can
be
included
in
an
emissions
averaging
plan;
and
(
4)
not
requiring
a
hazard
or
risk
assessment
before
emissions
averaging
can
be
used
at
a
facility.

Commenter
IV­
D­
27
stated
that,
at
some
PCWP
facilities,
there
may
be
process
units
that
have
the
potential
to
emit
quantities
of
HAP
equal
to
or
greater
than
the
most
commonly
controlled
units
 
dryers
and
presses
 
but
with
a
lower
volume
of
exhaust
gas
to
be
treated
compared
to
dryers
and
presses.
The
commenter
noted
that
the
emissions
from
these
other
units
2­
123
do
not
require
control
under
the
point­
by­
point
compliance
options;
however,
under
emissions
averaging,
these
sources
could
be
controlled
to
generate
credits,
and
thus,
emissions
averaging
will
allow
affected
sources
to
achieve
the
same
environmental
gains
as
achieved
by
point­
by­
point
compliance,
but
at
reduced
cost.
The
commenter
also
noted
that
the
emissions
averaging
program
in
the
HON
includes
a
discount
factor,
whereas,
the
proposed
PCWP
emissions
averaging
program
does
not.
The
commenter
stated
that
the
rationale
for
including
a
discount
factor
in
the
HON
does
not
apply
to
PCWP
sources.
According
to
the
commenter,
EPA
determined
in
the
HON
that
it
was
appropriate
for
the
industry
to
share
any
cost
savings
realized
from
emissions
averaging
because
the
costs
of
controlling
different
emission
points
could
vary
significantly;
however,
in
the
PWCP
industry,
EPA
found
that
the
types
of
process
units
and
the
emissions
from
them
are
more
similar
than
dissimilar
across
sources.
The
commenter
further
noted
that,
not
only
are
the
emissions
from
all
PWCP
process
units
are
similar,
but
they
also
require
similar
controls.
For
these
reasons,
the
commenter
stated
that
a
discount
factor
is
not
needed
in
the
PCWP
emissions
averaging
program
to
maintain
an
equivalent
compliance
cost
between
compliance
options.
The
commenter
also
agreed
with
the
proposal
that
the
number
of
sources
that
can
be
included
in
the
proposed
PCWP
emissions
averaging
program
should
not
be
limited.
The
commenter
noted
that,
under
the
HON,
the
number
of
emission
points
was
limited
because
of
enforcement
concerns
due
to
the
complexity
and
large
number
of
emission
points
in
each
HON
facility.
The
commenter
further
noted
that,
for
PCWP
facilities,
the
type
and
number
of
emissions
points
is
substantially
smaller,
minimizing
enforcement
concerns.
Finally
the
commenter
expressed
concurrence
with
the
exclusion
of
a
hazard/
risk
benefit
analysis
from
the
proposed
PCWP
emissions
averaging
program.
The
commenter
stated
that,
unlike
the
HON
facilities
(
which
must
conduct
a
hazard/
risk
benefit
analysis
due
to
the
many
pollutants
[
with
varying
toxicities]
emitted
from
many
emission
points),
PCWP
facilities
have
few
pollutants
of
concern
and
have
similar
HAP
emissions
from
the
emission
points
that
would
be
used
to
generate
debits
and
credits.

Commenter
IV­
D­
33
objected
to
the
inclusion
of
an
emissions
averaging
option
in
the
rule
because
the
proposed
option
is
based
on
mass
of
HAP
rather
than
health
effects.
The
commenter
asserted
that
removing
a
certain
mass
of
HAP
regardless
of
identity
is
not
equivalent
to
the
other
compliance
options,
and
when
the
dose­
response
and
exposure
data
are
examined,
it
is
obvious
that
trading
one
HAP
for
another
to
meet
a
required
mass
removal
(
RMR)
is
not
an
acceptable
2­
124
solution.
The
commenter
noted
that
there
are
currently
no
methods
for
weighting
the
toxicity
of
HAP,
and
that
the
effects
of
simultaneous
exposure
to
several
HAP
also
are
unknown.
The
commenter
contended
that,
because
EPA's
own
risk
assessment
data
presented
in
the
preamble
shows
that
80
percent
of
the
PCWP
facilities
in
the
United
States
pose
unacceptable
risk
to
the
populations
near
these
facilities
(
i.
e.,
cancer
risks
greater
than
greater
than
one
in
one
million),

EPA
should
require
emission
reductions
at
these
facilities
instead
of
proposing
a
"
flawed
trading
scheme"
that
will
potentially
increase
toxic
emissions
at
certain
process
units.

Response:
We
acknowledge
the
comments
in
support
of
the
emissions
averaging
plan
(
EAP)
and
have
retained
the
proposed
provisions
in
the
final
rule
with
some
minor
changes.
The
final
rule
changes
proposed
§
63.2240(
c)(
2)(
iii)
regarding
the
exclusion
of
process
units
controlled
to
comply
with
other
rules
from
PCWP
emissions
averages
as
follows:

(
iii)
You
may
not
include
in
your
emissions
average
process
units
controlled
to
comply
with
a
State,
Tribal,
or
Federal
rule
other
than
this
subpart,
except
when
the
control
system
installation
and
process
unit
inclusion
in
the
emissions
average
both
pre­
date
the
effective
date
of
the
State,
Tribal,
or
Federal
rule.

We
removed
the
last
phase
as
shown
above
to
prevent
PCWP
facilities
from
taking
credit
for
future
emissions
reductions
that
may
be
required
as
part
of
another
rule.
The
emissions
averaging
provisions
must
ensure
the
same
degree
of
reduction
that
would
be
achieved
through
point­

bypoint
compliance
with
the
PCWP
rule
and
any
other
rules
to
which
a
PCWP
is
subject.
For
example,
if
two
process
units
are
part
of
a
PCWP
emissions
average
and
the
emissions
from
the
first
process
unit
must
be
further
reduced
at
a
later
date
as
part
of
another
rulemaking,
the
source
cannot
then
recalculate
the
emissions
average
to
get
credit
for
the
increased
emission
reduction
from
the
first
process
unit
and
then
reduce
the
required
emission
reduction
from
the
second
process
unit.
If
the
PCWP
facility
were
allowed
to
take
credit
for
the
reduction
required
as
part
of
the
non­
PCWP
rule,
then
the
overall
emission
reduction
would
be
less
than
it
would
have
been
in
the
absence
of
emissions
averaging.
In
this
example,
the
remaining
process
unit
would
have
to
become
part
of
a
new
emissions
average
(
that
does
not
include
any
process
units
controlled
to
comply
with
other
rules)
or
meet
one
of
the
other
compliance
options
(
e.
g.,
90
percent
reduction
in
emissions.)
2­
125
We
disagree
with
commenter
IV­
D­
33
that
the
inclusion
of
the
EAP
will
potentially
increase
toxic
emissions
at
certain
PCWP
process
units.
As
stated
in
the
preamble
to
the
proposed
rule
(
68
FR
1289­
1290,
January
9,
2003),
we
based
the
emissions
averaging
provisions
(
in
part)
on
the
emissions
averaging
provisions
in
the
HON.
However,
there
are
differences
in
the
two
rules
due
to
the
differences
between
PCWP
facilities
and
HON
facilities.
The
HON
requires
a
hazard
and
risk
study
for
emission
points
included
in
an
emissions
average
largely
because
of
the
many
pollutants
and
many
emission
points
at
the
source.
The
PCWP
facilities
have
fewer
pollutants
of
concern
and
are
likely
to
have
similar
HAP
emissions
from
the
emission
points
(
process
units)
that
would
be
used
to
generate
debits
and
credits.
The
PCWP
facilities
emit
primarily
six
HAP
(
along
with
very
small
amounts
of
other
HAP),
whereas
HON
facilities
may
emit
over
140
different
HAP
in
substantial
quantities.
The
PCWP
facilities
choosing
to
comply
through
emissions
averaging
must
account
for
the
emissions
of
the
six
primary
HAP
(
defined
as
"
total
HAP"
in
the
final
rule),
which
represent
96
percent
of
the
HAP
emitted
from
PCWP
process
units.
Because
the
MACT
control
technologies
are
effective
in
reducing
the
emissions
of
all
six
of
these
HAP,
and
the
EAP
requires
the
use
of
add­
on
control
technologies
for
creditgenerating
sources
in
the
EAP,
we
believe
that
the
EAP
will
achieve
a
hazard/
risk
benefit
comparable
to
what
would
be
achieved
through
point­
by­
point
compliance.
The
same
emission
reduction
would
be
achieved
using
emissions
averaging
as
would
have
been
achieved
through
point­
by­
point
compliance,
and
therefore,
there
would
not
be
an
increase
in
emissions
or
exposures
to
these
emissions
at
populations
near
PCWP
facilities.
We
also
note
that,
although
the
final
rule
does
not
require
a
hazard/
risk
study,
States
will
still
have
the
discretion
to
require
a
PCWP
facility
that
requested
approval
of
an
EAP
to
conduct
a
hazard/
risk
study
(
or
to
preclude
the
facility
from
using
emissions
averaging
altogether).

2.6.4.2
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
requested
that
EPA
modify
the
emissions
averaging
provisions
to
allow
sources
to
receive
credit
for
achieving
emissions
reductions
greater
than
90
percent.
The
commenters
contended
that
restricting
sources
to
a
maximum
control
efficiency
credit
of
90
percent
will
eliminate
an
important
incentive
for
sources
to
take
extra
steps
to
maximize
the
efficiency
of
addon
control
devices.
The
commenters
stated
that
allowing
credit
for
efficiencies
above
90
percent
would
encourage
those
operators
who
are
able
to
achieve
these
levels
to
run
controls
in
the
most
efficient
manner,
as
opposed
to
running
at
90
percent,
regardless
of
capability.
The
commenters
2­
126
noted
that
other
control
options
included
in
the
proposed
rule
allow
credit
for
achieving
greater
than
90
percent
control.
The
commenters
pointed
to
the
add­
on
control
options
for
methanol
and
formaldehyde
(
i.
e.,
if

10
ppmv
in
the
control
device
inlet,
then
meet

1
ppmv
in
the
outlet)
as
options
that
require
greater
than
90
percent
control.
The
commenters
also
stated
that
the
press
provisions
for
90
percent
capture
and
control
acknowledge
that
facilities
will
have
to
achieve
greater
than
90
percent
reduction
from
control
devices
in
order
to
meet
the
90
percent
reduction
limit
when
capture
is
less
than
90
percent.
At
a
minimum,
the
commenters
requested
that
the
final
rule
allow
credit
for
control
efficiencies
greater
than
90
percent
for
those
process
units
with
no
MACT
control
requirements.
The
commenters
contended
that
because
these
emission
units
are
not
required
to
meet
any
specified
percent
reduction,
there
is
no
logical
reason
why
they
should
be
limited
to
receiving
credit
only
for
a
specified
level
of
removal
(
90
percent).

Response:
We
disagree
with
the
commenters'
request
to
allow
credit
for
achieving
greater
than
90
percent
control
of
HAP
as
part
of
an
EAP.
We
note
that
the
90
percent
MACT
floor
level
(
upon
which
the
emissions
averaging
provisions
are
based)
reflects
the
inherent
variability
in
uncontrolled
emissions
from
PCWP
process
units
and
the
decline
in
performance
of
control
devices
applied
to
these
process
units.
The
data
set
used
to
establish
the
MACT
floor
is
comprised
of
point­
in­
time
test
reports,
some
of
which
show
a
greater
than
90
percent
control
efficiency;
however
we
selected
90
percent
as
the
MACT
floor
level
of
control
to
reflect
inherent
performance
variability.
Therefore,
it
would
be
inappropriate
to
allow
PCWP
facilities
to
receive
credit
for
similar
point­
in­
time
performance
tests
showing
greater
than
90
percent
control,

considering
that
the
same
types
of
control
technologies
would
be
used.
We
expect
that
some
new
installations
of
add­
on
controls
will
show
greater
than
90
percent
control
efficiency
during
initial
performance
tests
because
these
units
likely
will
be
designed
for
greater
than
90
percent
control
efficiency
to
account
for
inherent
variations
in
performance
over
time
and
to
ensure
continuous
compliance
in
later
years.
We
also
have
included
routine
control
device
maintenance
exemptions
to
help
PCWP
facilities
to
ensure
that
the
add­
on
controls
are
properly
maintained
so
that
the
90
percent
compliance
can
be
achieved
on
a
continuous
basis.

Regarding
the
two
examples
given
by
the
commenters,
as
explained
in
our
previous
response
to
comment
No.
2.6.2.3,
the
add­
on
control
options
for
methanol
and
formaldehyde
do
not
require
greater
than
90
percent
control.
We
also
note
that
the
MACT
floor
level
of
90
percent
is
based
solely
on
the
performance
of
the
add­
on
control
devices
for
dryers
and
other
2­
127
process
units
where
emissions
capture
is
not
at
issue.
When
setting
the
MACT
floor
for
presses
at
proposal,
we
determined
that
those
presses
designed
to
meet
EPA
Method
204
design
criteria
should
be
able
to
claim
100
percent
capture,
such
that
the
combined
(
overall)
capture
and
control
efficiency
also
would
be
90
percent
(
i.
e.,
0.90
x
1.00
=
0.90).
Although
we
have
changed
the
requirements
related
to
the
wood
products
enclosures
in
the
final
rule
(
see
section
2.3),
the
MACT
floor
level
of
90
percent
has
not
changed
(
i.
e.,
wood
products
enclosures
are
still
credited
with
100
percent
capture,
and
MACT
control
devices
are
still
capable
of
reducing
emissions
by
90
percent).
Thus,
the
overall
control
requirement
for
the
affected
process
units
remains
at
90
percent.
Regarding
the
commenters'
assertion
that
the
press
provisions
for
90
percent
capture
and
control
acknowledge
that
facilities
will
have
to
achieve
greater
than
90
percent
reduction
from
control
devices
in
order
to
meet
the
90
percent
reduction
limit
when
capture
is
less
than
90
percent,
we
note
that
it
will
be
impossible
to
achieve
90
percent
capture
and
control
if
capture
is
less
than
90
percent.
Under
the
EAP,
a
press
may
receive
credit
for
achieving
greater
than
90
percent
control
via
the
add­
on
control
device;
however,
the
combined
capture
and
control
credit
for
the
press
cannot
exceed
90
percent.
Regarding
the
commenters'
request
to
allow
credit
for
greater
than
90
percent
control
for
nonregulated
sources,
we
maintain
that
this
would
be
inappropriate
because
the
same
issues
of
emissions
variability
and
control
device
performance
reflecting
our
calculations
of
what
MACT
levels
are
consistently
achievable
apply
to
those
emission
sources,
and
they
likely
would
share
control
devices
with
regulated
sources.

2.6.4.3
Comment:
Commenter
IV­
D­
11
stated
that
because
emissions
averaging
credits
would
be
based
on
actual
emissions
from
process
units
operating
"
below
representative
operating
conditions,"
the
credits
generated
would
be
small
and
not
worth
the
extra
effort
to
track
emissions
averaging
data
to
determine
compliance.
The
commenter
stated
that
reductions
beyond
the
required
MACT
emission
level
(
90
percent
at
proposal)
would
be
the
best
way
to
achieve
an
averaging
compliance
option.
The
commenter
stated
that
the
reductions
should
be
based
on
emissions
in
pounds
of
total
HAP,
operating
at
"
representative
operating
conditions,"
on
a
semiannual
basis.

Response:
We
disagree
with
the
commenter
that
the
credits
generated
through
emissions
averaging
would
be
"
small
and
not
worth
the
extra
effort
to
track."
First,
the
emissions
averaging
provisions
in
the
PCWP
rule
do
not
require
testing
of
process
units
while
they
are
operating
below
representative
conditions;
the
rule
requires
testing
while
process
units
are
operating
at
2­
128
representative
conditions,
as
the
commenter
suggests.
Second,
credit­
generating
units
must
be
equipped
with
add­
on
control
systems,
and
the
greater
the
emission
reductions
achieved
with
these
control
systems,
the
greater
the
resulting
credited
emissions
reductions;
therefore,
it
would
be
very
unlikely
that
a
PCWP
facility
would
go
to
the
expense
of
installing
a
control
device
that
would
only
achieve
minimal
HAP
emission
reductions.
Third,
the
emissions
averaging
provisions
are
offered
as
an
alternative
to
the
add­
on
control
system
compliance
options,
and
as
such,
must
achieve
an
emission
reduction
equivalent
to
what
would
be
achieved
through
these
other
options.
The
emission
averaging
provisions
were
never
intended
to
result
in
emission
reductions
greater
than
those
achieved
through
implementation
of
the
MACT
floor.

2.6.4.4
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
requested
that
EPA
modify
the
emissions
averaging
provisions
to
allow
sources
to
receive
credit
for
production
curtailment.
The
commenters
contended
that
taking
production
restrictions
and
eliminating
emission
points
to
comply
with
a
standard
is
not
unprecedented,

pointing
to
synthetic
minors
that
become
area
sources,
the
"
Oregon
PAL
program,"
and
State
permit
limits
that
include
production
limits.
The
commenters
stated
that,
once
an
initial
baseline
has
been
established,
any
steps
taken
to
reduce
emissions
by
90
percent
should
meet
the
legal
requirements
of
MACT
and
the
proposed
requirements
of
the
rule.

Response:
As
stated
in
the
preamble
to
the
proposed
rule
(
68
FR
1285,
January
9,
2003),

we
do
not
have
facility­
wide
uncontrolled
emissions
data
and
facility­
wide
controlled
emissions
data
for
each
PCWP
facility
to
determine
the
baseline
emissions
and
percent
reduction
in
HAP
achieved
by
each
facility.
Therefore,
the
MACT
floor
is
not
based
on
facility­
wide
emissions
and
emissions
reductions
achieved
during
a
particular
year.
Instead,
the
MACT
floor
is
based
on
(
1)

the
presence
or
absence
of
certain
MACT
controls
(
in
place
as
of
April
2000)
on
certain
types
of
process
units,
and
(
2)
test
data
showing
that
these
controls
reduce
emissions
by
greater
than
or
equal
to
90
percent.
We
applied
the
MACT
floor
methodology
at
the
process
unit
level
because
we
had
the
most
accurate
data
at
the
process­
unit
level,
making
this
approach
the
most
technically
and
legally
sound.
The
PCWP
industry
is
very
dynamic,
with
frequent
shutdowns
of
equipment
for
maintenance
and
occasional
longer
(
e.
g.,
month­
long)
shutdowns
if
demand
drops.
The
reported
operating
hours
of
various
PCWP
equipment
during
1997
(
base
year
for
the
MACT
survey)
varied
widely.
10
The
PCWP
rule
requires
emissions
from
specified
process
units
at
impacted
PCWP
facilities
to
be
reduced
by
90
percent,
regardless
of
what
the
levels
of
emissions
2­
129
are
for
those
facilities
in
a
particular
year.
Therefore,
implementation
of
the
final
PCWP
rule
at
individual
PCWP
facilities
will
result
in
greater
emission
reductions
in
years
of
greater
production
and
lesser
emission
reductions
during
years
of
lower
production.
As
mentioned
in
the
response
to
the
previous
comment,
the
emissions
averaging
provisions
must
achieve
emission
reductions
that
are
greater
than
or
equal
to
those
that
would
be
achieved
using
the
add­
on
control
systems
compliance
options
which
specify
which
process
units
must
be
controlled.
If
we
allowed
"
credit"

for
production
curtailments,
the
overall
emission
reduction
achieved
through
the
emissions
averaging
provisions
would
not
be
equivalent
to
what
would
be
achieved
through
the
use
of
the
add­
on
control
systems
compliance
options,
and
therefore,
the
EAP
would
not
be
a
MACTequivalent
alternative.
For
example,
if
we
allowed
production
curtailments
to
count
towards
an
emissions
average,
then
a
facility
that
shuts
down
one
of
two
parallel
production
lines
(
each
of
which
includes
dryers
and
a
press,
plus
HAP­
emitting
equipment
that
does
not
have
associated
control
requirements)
may
not
be
required
to
control
the
emissions
from
any
of
the
dryers
or
press
on
the
remaining
production
line.
However,
if
the
same
facility
opted
to
comply
with
the
add­
on
control
systems
compliance
options,
then
they
would
be
required
to
control
the
press
and
dryer
emissions
from
the
remaining
production
line
by
90
percent
regardless
of
whether
or
not
the
other
production
line
was
shut
down.
In
order
to
maintain
equivalency
between
the
emissions
averaging
provisions
and
the
add­
on
control
systems
compliance
options
and
to
preserve
the
required
HAP
emission
reductions,
the
final
PCWP
rule
does
not
allow
production
curtailment
to
be
counted
as
part
of
an
EAP.

2.6.4.5
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
requested
that
EPA
modify
the
emissions
averaging
provisions
to
allow
sources
to
receive
credit
for
pollution
prevention
projects.
According
to
the
commenters,
not
allowing
pollution
prevention
encourages
the
use
of
add­
on
controls,
such
as
incineration,
rather
than
environmentally
beneficial
options
that
may
not
involve
add­
on
control
technology.
The
commenters
cited
three
ways
in
which
pollution
prevention
could
be
used
to
generate
credits
in
an
emissions
averaging
plan.
First,
pollution
prevention
could
be
used
to
reduce
emissions
at
a
process
unit
that
is
required
to
be
controlled
by
an
amount
greater
than
the
MACT
level
(
i.
e.,

greater
than
90
percent
emission
reduction);
however,
the
commenter
expects
that
this
would
be
very
difficult
to
do.
Second,
pollution
prevention
could
be
used
to
reduce
emissions
from
a
process
unit
that
is
not
required
to
be
controlled,
by
90
percent
or
more.
Finally,
pollution
2­
130
prevention
could
be
used
at
a
regulated
emission
unit
that
utilizes
an
add­
on
control
technology
but
does
not
achieve
the
MACT
limit
(
e.
g.,
a
biofilter
achieving
80
percent
removal).
In
the
latter
case,
pollution
prevention
would
be
used
to
achieve
the
additional
incremental
emissions
reductions
needed
to
reach
the
MACT
limit.
The
commenters
asserted
that
quantifying
emissions
from
pollution
prevention
projects
would
not
be
difficult
under
the
PCWP
emissions
averaging
program.
According
to
the
commenters,
the
facility
would
calculate
the
"
total
allowable
emissions"
and
then
apply
a
90
percent
reduction
to
determine
the
equivalent
MACT
floor
level
of
control,
and
then
compare
the
total
emission
level
to
the
controlled
emission
level.
With
this
approach,
an
initial
test
will
be
used
to
establish
initial
compliance
and
then
testing
would
occur
annually
to
demonstrate
continuing
compliance.

Response:
We
disagree
with
the
commenters'
suggestion
to
modify
the
emissions
averaging
provisions
to
allow
sources
to
receive
credit
for
P2
projects
because
(
1)
compliance
options
(
i.
e.,
PBCO)
already
exist
for
any
P2
projects
that
prove
to
be
feasible
and
(
2)
inclusion
of
currently
undemonstrated
P2
projects
within
EAPs
would
unnecessarily
complicate
these
plans
and
hamper
enforcement.
We
also
disagree
with
the
commenters'
assertion
that
quantifying
the
emissions
reductions
from
P2
projects
would
not
be
difficult.
Quantifying
the
emissions
reductions
associated
with
P2
projects
has
historically
been
a
contentious
issue,
especially
when
a
baseline
emission
level
must
be
established
from
which
to
calculate
the
emissions
reduction.
We
believe
that
the
same
issues
apply
for
PCWP
facilities,
especially
given
the
fact
that
P2
techniques
have
not
been
widely
used
or
documented
in
the
PCWP
industry,
and
therefore
were
not
the
basis
for
determining
the
MACT
floor.
In
contrast,
emission
reductions
achieved
through
the
use
of
add­
on
control
systems
are
easily
documented.
The
PBCO
was
established
to
address
the
future
development
and
implementation
of
P2
techniques;
however,
the
resultant
PBCO
limits
do
not
require
that
emission
reductions
be
determined.
Instead,
sources
simply
demonstrate
that
they
are
below
the
PBCO
limit
and
will
continue
to
operate
in
a
manner
that
ensures
they
will
remain
below
the
PBCO
limit.
We
believe
that
the
lack
of
a
discount
factor
in
the
emissions
averaging
provisions
in
the
final
PCWP
rule
further
justifies
our
decision
not
to
allow
credit
for
P2
techniques
as
part
of
an
EAP.
Under
the
HON,
sources
that
elect
to
emissions
average
must
reduce
emissions
throughout
the
HON
facility
by
10
percent
more
than
is
required
by
point­

bypoint
compliance
to
share
with
the
environment
any
cost
savings
realized
from
emissions
averaging
and
to
account
for
uncertainties
in
determining
emission
reductions
under
the
EAP.
2­
131
Unlike
the
HON,
the
PCWP
rule
does
not
require
a
10
percent
discount
factor
in
the
emissions
credit
calculations.
We
believe
that
the
inclusion
of
the
PBCO
provides
sufficient
opportunities
and
incentives
for
PCWP
facilities
to
develop
and
implement
P2
techniques.
We
also
note
that
because
the
PBCO
is
based
on
90
percent
reduction
from
highest­
emitting
source,
there
should
be
plenty
of
opportunity
for
the
industry
to
comply
using
P2,
should
such
techniques
actually
be
developed.
Finally,
as
noted
in
previous
responses,
the
final
rule
already
allows
PCWP
facilities
to
use
both
P2
and
emissions
averaging
at
the
same
facility;
sources
are
only
limited
in
that
they
can't
apply
both
options
to
a
single
process
unit.

2.6.4.6
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
requested
that
EPA
modify
the
emissions
averaging
provisions
to
allow
sources
to
include
the
PBCO
as
part
of
an
EAP.
Specifically,
the
commenters
requested
that
sources
be
allowed
to
apply
the
emissions
credit
generated
from
controlling
a
process
unit
for
which
control
is
not
required
to
another
process
unit
seeking
to
comply
with
a
PBCO
limit.
Commenter
IV­
D­

27
gave
an
example
where
a
facility
would
control
emissions
from
a
board
cooler
and
then
apply
the
resultant
emission
reduction
to
a
press
that
had
emissions
above
the
applicable
PBCO
limit;
by
applying
the
emissions
credit
to
the
press,
the
press
emissions
would
be
reduced
below
the
PBCO
limit
such
that
no
control
would
be
required
on
the
press.
The
commenters
stated
that
EPA
should
allow
combining
of
these
two
compliance
options
(
emissions
averaging
and
PBCO)

because
doing
so
would
make
the
rule
more
cost­
effective,
and
the
result
would
be
equally
beneficial
to
the
environment.
The
commenters
stated
that
combining
of
compliance
options
has
been
allowed
in
other
rules,
specifically
in
the
Paper
and
Other
Web
Coating
NESHAP.
The
commenters
also
stated
that
combining
the
two
compliance
options
would
allow
more
facilities
to
use
these
options
and
would
result
in
equal
emissions
reductions.
When
implementing
this
approach,
the
commenters
also
requested
that
emissions
be
calculated
in
terms
of
tons
per
year
rather
than
pounds
per
year
to
be
more
consistent
with
terminology
used
in
most
permits,
and
for
other
reporting
requirements,
such
as
emission
inventories,
already
in
place
at
wood
product
facilities.

Response:
The
commenter
is
incorrect
in
stating
that
combining
these
two
options
(
emissions
averaging
and
PBCO)
will
result
in
equivalent
emissions
reductions.
As
stated
in
our
response
to
previous
comments
regarding
the
PBCO,
we
developed
the
PBCO
limits
to
provide
an
option
for
sources
that
develop
P2
techniques.
The
PBCO
limits
represent
applicability
cutoffs
2­
132
such
that
sources
with
emissions
below
the
applicable
PBCO
limits
are
not
required
to
further
reduce
those
emissions
below
MACT
levels.
By
combining
PBCO
limits
with
the
EAPs
as
proposed
by
the
commenter,
we
would
be
allowing
higher­
emitting
sources
(
i.
e.,
those
that
cannot
meet
a
PBCO
and
which
should
be
controlled)
to
escape
controls
by
artificially
lowering
their
emissions
using
the
credits
from
the
EAP.
This
is
counter
to
the
intent
of
the
PBCO
and
would
result
in
lower
emission
reductions
than
would
be
achieved
without
combining
these
two
compliance
options;
therefore,
this
does
not
represent
an
option
that
is
equivalent
to
the
MACT
floor
and
is
not
allowed
in
the
final
rule.
To
demonstrate
how
the
combining
of
these
compliance
options
results
in
lower
emission
reductions,
we
have
taken
the
example
provided
by
the
commenter
and
presented
the
emission
reductions
that
would
occur
using
each
compliance
method
separately
and
together.
As
shown
in
Table
2­
4,
the
90
percent
control
option
and
the
emissions
averaging
provisions
(
which
incorporate
the
90
percent
control
requirements)
result
in
equivalent
emission
reductions
(
i.
e.,
8.1
tons
of
HAP
reduced
per
6­
month
reporting
period).

Compliance
with
the
PBCO
would
require
the
facility
to
develop
a
P2
technique
that
would
eliminate
at
least
1.5
tons
of
uncontrolled
HAP
from
the
press
per
6­
month
period.
Although
this
"
emission
reduction"
is
lower
than
what
would
be
achieved
through
the
use
of
add­
on
controls,

we
would
allow
this
because
of
the
benefits
of
pollution
prevention
(
i.
e.,
absence
of
secondary
environmental
impacts
generated
through
the
use
of
add­
on
control
systems
on
low­
emitting
emission
units).
As
shown
in
option
4
of
Table
2­
3,
the
use
of
the
PBCO
limits
in
EAPs
artificially
lowers
emissions
from
process
units
that
are
not
inherently
low­
emitting
sources
to
levels
that
would
qualify
as
low­
emitting
(
below
PBCO
limits).
This
conflicts
with
the
purpose
of
including
the
PBCO
in
the
rule
and,
as
stated
above,
conflicts
with
the
MACT
floor;
therefore,
the
final
rule
does
not
allow
the
inclusion
of
PBCO
within
an
EAP.
As
for
reporting
emissions
in
EAPs
in
units
of
tons
per
year,
we
disagree
that
this
change
would
be
beneficial
and
have
retained
the
requirement
to
report
these
emissions
in
units
of
pounds
per
year
to
avoid
situations
where
compliance
is
achieved
through
rounding.
2­
133
Table
2­
4.
Effect
of
Combining
Compliance
Options
on
Emission
Reductions
Achieved
Total
HAP
Emissions
Data:
Press
emissions
=
36,000
lb/
yr;
(
0.36
lb/
MSF)
Cooler
emissions
=
10,000
lb/
yr;
(
0.10
lb/
MSF)
Production
rate
=
100
MMSF/
yr;
50
MMSF/
6­
month
period
PCWP
Rule
Requirements:
Press:
(
1)
Reduce
emissions
by
90%,
or
(
2)
include
in
an
emissions
average,
or
(
3)
comply
with
PBCO
limit
of
0.3
lb/
MSF.
Rule
does
not
allow
combining
of
PBCO
with
other
compliance
options
(
4).

Cooler:
None
OPTION
STRATEGY
EMISSION
REDUCTION,
lbs
per
6­
month
period
(
1)
Comply
with
90%
reduction
Press:
Use
add­
on
control
system
to
reduce
emissions
by
90%

Cooler:
No
action
16,200
(
2)
Comply
using
emissions
averaging
Press:
Use
add­
on
control
system
to
reduce
emissions
by
at
least
65%
(
11,700
lbs
per
6­
month
period)
(
undercontrolled
source
in
EAP)

Cooler:
Use
add­
on
control
system
to
reduce
emissions
by
90%
(
4,500
lbs
per
6­
month
period)
16,200
(
3)
Comply
with
PBCO
Press:
use
pollution
prevention
techniques
to
reduce
uncontrolled
press
emissions
from
0.36
lb/
MSF
to

0.30
lb/
MSF
(
equal
to
a
17+%
"
reduction")

Cooler:
No
action
3,000
(
4)
Comply
with
EAP
that
incorporates
PBCO
(
option
suggested
by
commenter)
(
a)
Use
add­
on
controls
to
reduce
cooler
emissions
by
90%
(
4,500
lbs
per
6­
month
period),
resulting
in
a
credit
of
0.09
lb/
MSF
(
b)
Using
cooler
credit,
artificially
reduce
uncontrolled
press
emissions
from
0.36
lb/
MSF
to
0.27
lb/
MSF
(
c)
No
controls
are
applied
to
press
because
discounted
emission
rate
(
0.27
lb/
MSF)
is
less
than
the
PBCO
limit
of
0.30
lb/
MSF
4,500
2.6.4.7
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
requested
that
EPA
consider
an
"
enhanced
emissions
averaging
compliance
2­
134
option"
to
address
elements
in
the
proposed
emissions
averaging
program
that
the
commenter
believes
are
missing
or
require
modification
as
discussed
above
in
the
preceding
comments.
The
enhanced
EAP
would
allow
PCWP
facilities
to
focus
on
achieving
a
90
percent
emission
reduction
of
methanol,
formaldehyde,
or
THC
instead
of
the
proposed
90
percent
reduction
of
total
HAP
emissions.
The
baseline
level
of
methanol,
formaldehyde,
or
THC
emissions
would
be
calculated
using
data
from
the
regulated
process
units
(
e.
g.,
dryers
and
presses)
over
the
past
10
years
(
or
some
other
representative
period),
but
the
emissions
reductions
could
be
the
result
of
controlling
any
emissions
source.
Under
this
plan,
emission
reductions
could
be
achieved
with
add­
on
controls,
P2
projects,
and
operational
changes,
such
as
reformulation
of
the
product,

routing
process
unit
exhaust
to
existing
onsite
combustion
sources,
lowering
dryer
operating
temperatures,
partial
capture
and
control
of
process
unit
emissions,
increasing
use
of
hardwood
species,
production
curtailment,
production
caps,
and
scheduled
process
unit
downtime.

Commenters
IV­
D­
19
and
IV­
D­
27
provided
examples
to
show
how
the
emission
reductions
would
be
determined
under
each
scenario.
The
commenters
acknowledged
that
any
credit
generation
would
have
to
be
well
documented
and
verified,
and
that
monitoring
parameters
would
be
used
to
determine
continuous
compliance.
Like
the
proposed
EAP,
the
enhanced
EAP
would
only
apply
to
existing
facilities,
and
new
sources
would
be
required
to
meet
the
90
percent
reduction
level.
Under
the
plan,
any
changes
at
a
facility
that
resulted
in
an
increase
of
methanol,

formaldehyde,
or
THC
emissions
would
not
require
the
baseline
level
of
emissions
to
be
recalculated
as
long
as
the
increase
was
not
larger
than
10
percent
of
the
original
level.

Response:
We
disagree
with
the
commenters'
suggested
"
enhanced
emissions
averaging
compliance
option"
and
have
retained
the
proposed
emissions
averaging
provisions
in
the
final
rule
with
only
minor
revisions.
Our
objections
to
some
of
the
features
of
the
suggested
enhanced
emissions
averaging
compliance
option,
such
as
allowing
credit
for
production
curtailments
and
P2
techniques,
have
been
documented
in
previous
responses
(
see
responses
to
comment
Nos.

2.6.4.1
through
2.6.4.6).
Regarding
the
suggestion
to
allow
compliance
to
be
determined
based
on
methanol,
formaldehyde,
or
THC
emissions,
we
maintain
that
the
EAP
needs
to
be
based
on
total
HAP
(
i.
e.,
total
emissions
of
the
six
primary
HAP
emitted
from
PCWP
process
units).
We
note
that
the
predominant
HAP
emitted
from
a
given
process
unit
varies,
with
some
process
units
emitting
methanol
as
the
predominant
HAP
and
others
emitting
formaldehyde
or
acetaldehyde
as
the
predominant
HAP.
However,
the
predominant
HAP
will
always
be
one
of
the
six
we
have
2­
135
identified
in
the
definition
of
total
HAP
in
the
PCWP
rule.
If
we
based
the
EAP
on
only
one
pollutant,
process
units
that
emit
the
target
HAP
in
small
quantities
will
not
be
correctly
accounted
for
in
the
EAP,
resulting
in
potentially
less
stringent
control
and
greater
potential
risk
than
would
result
with
other
control
options.
We
did
not
include
a
hazard/
risk
study
as
part
of
the
proposed
EAP
because
we
were
requiring
that
the
emission
reductions
be
based
on
total
HAP,

and
PCWP
process
units
generally
emit
the
same
six
primary
HAP,
although
in
different
quantities
and
ratios.
Basing
the
EAP
on
a
single
pollutant
would
undermine
our
basis
for
not
requiring
a
risk
analysis.
We
also
note
that,
while
THC
emissions
may
be
an
acceptable
surrogate
for
monitoring
the
performance
of
an
add­
on
control
device
(
same
control
device
mechanisms
that
reduce
THC
emissions
reduce
HAP
emissions),
THC
emissions
are
not
an
accurate
surrogate
for
establishing
baseline
HAP
emissions,
and
thus,
the
EAP
should
not
be
based
solely
on
THC
emissions.
Although
all
PCWP
process
units
emit
THC,
THC
emissions
from
softwoods
are
substantially
higher
than
from
hardwoods
due
to
non­
HAP
compounds
(
e.
g.,
pinenes)
present
in
softwoods.
Therefore,
allowing
sources
to
focus
on
THC
reductions
by
increasing
hardwood
usage
might
reduce
THC
emissions
but
would
have
a
minimal
impact
on
HAP
emissions.

Regarding
the
proposed
idea
to
increase
the
use
of
hardwood
species,
we
note
that
elsewhere
in
their
comments
(
see
comment
No.
2.7.20.3),
the
same
commenter
stressed
the
difficulties
associated
with
maintaining
a
consistent
wood
material
flow
in
terms
of
species,

moisture
content,
etc.,
which
would
suggest
that
an
operating
condition
based
on
maintaining
a
set
level
of
wood
species
would
be
unworkable.
For
veneer
dryers,
where
species
identification
(
hardwood
versus
softwood),
and
thus
enforcement,
is
fairly
straightforward
from
the
standpoint
of
both
visual
inspection
and
end
product,
we
have
already
established
separate
MACT
floors
for
softwood
and
hardwood
veneer
dryers.
However,
when
the
end
product
is
particleboard
or
MDF,
and
the
raw
material
is
in
the
form
of
wood
chips,
planer
shavings,
or
sawdust,
determining
how
much
of
that
material
is
softwood
versus
hardwood
would
be
very
difficult
and
unenforceable.
Because
of
the
commenters'
concerns
that
an
operating
condition
based
on
wood
species
is
technically
unworkable
and
the
associated
enforcement
issues,
we
believe
this
option
is
not
viable.

Regarding
process
changes
such
as
reformulation,
lowering
dryer
temperature,
and
routing
process
unit
exhaust
to
existing
combustion
devices,
the
final
rule
already
includes
compliance
options
that
would
accommodate
all
of
these
strategies.
For
example,
product
2­
136
reformulation
and
lowering
dryer
temperature
are
potential
P2
options,
and
the
PBCO
limits
would
apply
if
the
P2
efforts
sufficiently
lower
emissions.
The
PCWP
rule
distinguishes
between
green
(
high
temperature,
high
moisture)
rotary
dryers
and
dry
(
low
temperature,
low
moisture)

rotary
dryers
and
requires
no
further
emissions
reductions
from
dry
rotary
dryers.
To
then
take
credit
for
the
difference
between
the
"
potential"
emissions
of
the
dryer
if
it
were
operated
at
higher
temperatures
as
a
"
green
dryer"
relative
to
operation
at
lower
temperatures
that
qualify
the
dryer
as
a
dry
dryer
(
exempt
from
regulation)
and
then
apply
that
credit
elsewhere
would
be
double­
counting.
By
operating
the
dryer
as
a
dry
dryer,
the
source
is
exempt
from
controls;
no
additional
credits
should
be
assigned
to
that
source.
Also,
as
with
many
of
the
proposed
process
changes/
P2
alternatives,
determining
a
baseline
from
which
to
calculate
an
emission
reduction
would
extremely
difficult
and
contentious,
needlessly
complicating
the
EAP
and
hampering
enforcement.
Regarding
the
use
of
existing
combustion
units
as
control
devices,
we
note
that
the
final
rule
already
allows
sources
to
route
emissions
to
onsite
combustion
units
for
incineration.

The
final
rule
also
allows
sources
to
control
a
portion
of
a
process
unit's
emission
stream
as
part
of
an
emissions
average.
However,
we
disagree
that
incineration
of
emissions
in
onsite
process
units
is
a
pollution
prevention
measure.
Therefore,
compliance
with
the
PBCO
using
process
incineration
is
not
allowed
in
the
final
rule.
The
add­
on
control
system
and
emissions
averaging
compliance
options
are
available
for
process
units
controlled
by
routing
exhaust
to
an
onsite
combustion
unit.

2.6.4.8
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
requested
that
EPA
extend
the
compliance
date
for
submittal
of
the
EAP.
The
commenters
stated
that
developing
an
EAP
will
be
an
involved
and
lengthy
process,
which
will
include
emission
testing
to
establish
credits/
debits,
development
of
emission
reduction
projects
(
e.
g.,
process
changes,
operating
restrictions)
and
identification
and
installation
of
controls.
The
commenters
contended
that
the
EAP
development
process
would
be
more
involved
than
the
other
compliance
options
requiring
only
controls,
and
yet,
the
EAP
option
has
the
shortest
effective
compliance
period
(
the
EAP
is
required
to
be
submitted
one
year
prior
to
the
compliance
date
for
review).
Therefore,
the
commenters
requested
that
the
date
of
submittal
of
the
EAP
be
changed
to
90
days
prior
to
compliance
with
an
extension,
if
needed,
of
up
to
one
year
for
inclusion
of
the
plan
into
a
federally
enforceable
mechanism.
2­
137
Response:
The
emissions
averaging
provisions
in
the
final
rule
are
essentially
the
same
as
those
provided
in
the
proposed
rule,
with
some
minor
clarifications.
We
believe
that
these
provisions
are
straightforward
and
uncomplicated,
and
that
developing
EAPs
would
not
be
"
an
involved
and
lengthy
process."
Therefore,
the
final
rule
retains
the
requirement
to
submit
the
EAP
for
review
one
year
prior
to
the
compliance
date.
We
note
that,
in
most
cases,
EAPs
developed
for
a
PCWP
facility
will
likely
include
only
a
small
number
of
process
units
within
the
facility.
We
also
note
that,
had
we
incorporated
some
of
the
suggested
changes
requested
by
the
commenters
(
e.
g.,
incorporating
P2
options
and
PBCO
into
EAPs)
,
the
emissions
averaging
provisions
would
have
been
much
more
complicated
and
more
difficult
to
enforce.
Finally,
we
believe
that
requiring
the
EAP
to
be
submitted
one
year
prior
to
the
compliance
date
gives
sources
time
to
adjust
their
compliance
strategies
should
the
EAP
prove
unworkable
(
e.
g.,

calculations
show
that
debits
exceed
credits)
or
otherwise
fail
to
be
approved.

2.6.4.9
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,
IV­
D­

43,
and
IV­
D­
56
stated
that
the
provision
in
§
63.2240(
c)(
2)(
vi)(
B)
(
which
prevents
emissions
during
monitoring
malfunction
and
periods
of
control
device
maintenance
covered
in
a
routine
control
device
maintenance
exemption
[
RCDME]
from
being
used
to
generate
credits
and
requires
maximum
debits)
of
the
proposed
rule
is
overly
restrictive
and
is
not
representative
of
the
actual
emissions
from
process
units.
The
commenters
noted
that
the
referenced
provision
states
that
no
credits
may
be
assigned
to
credit­
generating
process
units
and
maximum
debits
must
be
assigned
to
debit­
generating
process
units
during
periods
of
monitoring
malfunctions,
associated
repairs,
and
required
quality
assurance
or
control
activities.
The
commenters
contended
that
other
rules
(
e.
g.,
40
CFR
Part
75
 
Continuous
Emissions
Monitoring)
address
missing
data
in
a
more
structured
manner
and
do
not
impose
worst
case
debit
and
credit
estimates.
Therefore,
the
commenters
recommended
that
the
final
rule
include
a
"
more
realistic
approach"
for
times
of
monitoring
period
unavailability.

Response:
We
have
retained
the
provisions
in
§
63.2240(
c)(
2)(
vi)(
B)
(
which
prevents
emissions
during
monitoring
malfunction
and
RCDME
from
being
used
to
generate
credits
and
requires
maximum
debits)
in
the
final
rule
to
ensure
that
emissions
averaging
credits
equal
or
exceed
the
required
debits.
As
stated
previously,
the
emissions
averaging
provisions
in
the
final
rule
only
require
that
the
actual
emission
reductions
be
equal
to
(
or
greater
than)
the
required
emission
reductions.
Unlike
the
HON,
we
chose
not
to
apply
a
10
percent
discount
factor
to
the
2­
138
actual
emission
reductions
for
the
PCWP
rule,
and
thus
some
sources
may
operate
such
that
the
actual
HAP
reductions
are
very
close
to
the
required
HAP
reductions.
In
such
cases,
we
believe
it
is
especially
important
to
ensure
that
the
add­
on
control
systems
used
to
generate
the
necessary
credits
are
properly
operating.
Because
the
final
PCWP
rule
does
not
require
continuous
monitoring
of
HAP
emissions
or
periodic
stack
testing,
parameter
monitoring
will
be
used
to
ensure
that
these
add­
on
control
devices
continuously
operate
in
a
compliant
manner.
As
explained
in
section
2.7,
we
have
reduced
the
number
of
parameters
to
be
monitored
for
add­
on
control
devices.
For
example,
PCWP
sources
that
operate
RTOs
are
only
required
to
monitor
temperature,
which
is
both
a
reliable
indicator
of
performance
and
a
parameter
that
is
easily
measured
and
controlled.
Therefore,
we
expect
that
monitoring
malfunctions
will
be
both
infrequent
and
easily
corrected.

Regarding
the
commenter's
reference
to
the
provisions
for
handling
"
missing
data"
in
40
CFR
Part
75
(
Continuous
Emissions
Monitoring
for
NOx,
SOx,
opacity,
etc.,
for
the
Acid
Rain
Program),
we
note
that,
in
some
cases,
these
provisions
would
allow
sources
equipped
with
CEMS
to
substitute
average
data
for
measurements
made
before
and
after
the
period
of
missing
data,
but
in
other
cases,
they
would
have
to
assign
maximum
emission
rates
to
these
periods.
In
the
case
of
a
PCWP
facility,
the
maximum
emission
rate
would
be
equivalent
to
the
highest
uncontrolled
emission
rate,
which,
for
a
credit­
generating
source,
would
be
the
same
as
not
allowing
any
credits
during
those
periods.
For
a
debit­
generating
source,
the
maximum
rate
would
also
be
equal
to
the
highest
uncontrolled
emission
rate,
which
is
also
consistent
with
what
the
EAP
requires.
Regarding
the
use
of
average
values
before
and
after
an
outage,
we
do
not
believe
that
it
is
appropriate
to
allow
sources
to
substitute
average
data
for
periods
where
data
are
missing
and
then
count
those
periods
towards
credit
generation.
As
noted
above,
unlike
CEMS,

temperature
monitors
are
relatively
simple
pieces
of
equipment
that
are
generally
redundant
within
a
control
device
such
as
an
RTO,
and
thus,
periods
of
missing
data
should
be
minimal.

We
also
believe
that
it
is
necessary
to
exclude
from
EAP
calculations
those
emissions
that
occur
when
the
add­
on
control
device
used
to
generate
credits
is
undergoing
maintenance
as
part
of
an
RCDME.
During
periods
of
RCDME,
the
affected
process
units
are
not
subject
to
the
compliance
options
and
operating
requirements,
and
thus,
a
credit­
generating
emission
source
could
operate
during
these
periods
without
actually
achieving
any
emissions
reductions.
By
maintaining
these
restrictions
in
the
final
rule,
we
hope
to
maintain
the
integrity
of
the
emissions
2­
139
averaging
provisions
and
to
provide
an
incentive
for
PCWP
sources
to
maintain
their
monitoring
equipment
and
to
minimize
the
hours
they
will
claim
under
an
RCDME.

2.6.4.10
Comment:
Commenters
IV­
D­
12,
IV­
D­
19,
IV­
D­
21,
IV­
D­
27,
IV­
D­
28,

IVD
43,
and
IV­
D­
56
requested
that
EPA
allow
control
device
downtime
to
be
incorporated
into
the
emissions
averaging
program.
The
commenters
contended
that
there
are
process
units
in
the
PWCP
industry
that
require
greater
periods
of
control
device
downtime
than
are
provided
for
in
the
proposed
downtime
provisions
(
see
also
section
2.8
for
additional
comments
and
responses
regarding
routine
control
device
exemptions.)
The
commenters
requested
that
EPA
address
this
issue
by
specifically
stating
that
EAPs
can
be
used
as
an
additional
mechanism
for
generating
"
control
device
downtime
credits."
Commenter
IV­
D­
27
provided
an
example
to
demonstrate
how
this
process
would
work.
In
the
example
case,
a
mill
chooses
to
reduce
emissions
from
a
blender
by
90
percent.
Because
blender
emissions
are
not
required
to
be
controlled,
the
mill
would
earn
credit
for
the
resultant
emissions
reduction.
The
mill
would
then
apply
the
emissions
credit
to
a
rotary
dryer
system
which
is
equipped
with
a
control
device
that
requires
periods
of
control
device
downtime
in
excess
of
that
allowed
by
the
rule
(
i.
e,
3
percent
of
the
dryer
operating
hours).
Thus,
the
credit
generated
by
controlling
the
blender
would
offset
emissions
from
the
dryer
system
when
it
is
operating
in
"
abort
mode"
during
periods
of
control
device
downtime.
In
the
commenter's
example,
the
credits
created
by
controlling
the
blender
equated
to
9.6
percent
of
the
annual
emissions
from
the
dryer,
and
therefore,
9.6
percent
would
also
be
the
percentage
of
the
dryer
operating
hours
that
could
be
offset
by
the
blender
credits.

Response:
We
disagree
with
the
commenters'
request
to
allow
sources
to
apply
emission
reduction
credits
generated
for
one
process
unit
to
another
process
unit
in
order
to
increase
the
maximum
allowable
RCDME
hours
for
the
second
process
unit.
The
emissions
averaging
provisions
were
not
created
to
provide
an
opportunity
for
sources
to
increase
the
RCDME
allowances.
Furthermore,
as
discussed
in
response
to
comment
No.
2.8.1.3,
we
disagree
that
additional
downtime
is
needed
beyond
the
levels
already
allowed.
In
addition,
PCWP
sources
are
not
allowed
to
receive
emissions
averaging
credit
for
downtime
allowances
that
are
less
than
the
maximum
allowed
percentages.
Combining
RCDME
allowances
within
an
emissions
average
would
compromise
the
integrity
of
the
emissions
averaging
provisions,
which
are
based
on
the
MACT
floor
of
90
percent
control.
As
explained
previously,
the
data
set
used
to
determine
the
MACT
floor
included
several
control
devices
that
achieved
greater
than
90
percent
reduction
2­
140
during
performance
tests;
however,
the
90
percent
control
requirement
was
selected
instead
of
a
more
stringent
percent
reduction
to
account
for
variability
in
emissions
and
control
system
performance
over
time.
We
believe
that
the
variability
in
control
device
performance
can
be
related
to
the
need
for
control
device
maintenance
(
e.
g.,
an
RTO
with
one­
year­
old
media
may
perform
less
effectively
than
an
RTO
with
new
media).
Thus,
we
believe
that
the
MACT
floor
already
accounts
for
efficiency
losses
due
to
varying
degrees
of
maintenance
and
that
combining
RCDME
allowances
within
an
emissions
average
would
result
in
a
less
stringent
compliance
option.
Our
intention
in
including
the
RCMDE
provisions
was
not
to
provide
an
automatic
allowance
to
release
uncontrolled
emissions
up
to
3
percent
of
the
time,
but
instead,
to
improve
the
maintenance
and
uptime
of
add­
on
control
systems
at
PCWP.
We
believe
that
a
side
benefit
to
better
control
device
maintenance
will
be
more
efficient
control
devices
which
will
balance
out
any
increases
in
emissions
that
may
occur
during
periods
of
RCDME.
Combining
the
RCDME
with
emissions
averaging
would
upset
this
balance
in
addition
to
complicating
the
emissions
averaging
provisions.

2.6.4.11
Comment:
Commenter
IV­
D­
27
requested
clarification
regarding
how
the
required
and
actual
mass
removal
are
to
be
calculated
in
the
emission
averaging
program.

Specifically,
the
commenter
asked
that
EPA
make
several
clarifications
to
the
definitions
of
several
emissions
averaging
terms,
as
follows:

a.
Definition
of
UCEPi:
"
mass
of
total
HAP
from
an
uncontrolled
or
under­
controlled
process
unit
(
i)
that
generates
debits,
pounds
per
hour"

Clarification:
UCEPi
is
the
uncontrolled
mass
of
total
HAP
from
process
unit
(
i)
(
listed
in
Tables
1A
or
1B)
that
generates
debits.

b.
Definition
of
OCEPi:
"
mass
of
total
HAP
from
process
unit
(
i)
that
generates
credits,
pounds
per
hour"

Clarification:
OCEPi
is
the
uncontrolled
mass
of
total
HAP
from
process
unit
(
i)
that
generates
credits
(
which
can
include
those
process
units
listed
in
Tables
1A
or
1B),
pounds
per
hour.

c.
Definition
of
AMR:
"
actual
mass
removal
of
total
HAP
from
all
process
units
generating
credits
(
i.
e.,
all
process
units
that
are
controlled
as
part
of
the
Emissions
Averaging
Plan),
pounds
per
semiannual
period"
2­
141
Clarification:
"
actual
mass
removal
of
total
HAP
from
all
process
units
generating
credits
(
i.
e.,
all
process
units
that
are
controlled
as
part
of
the
Emissions
Averaging
Plan
which
can
include
under­
controlled
process
units
including
those
listed
in
Tables
1A
or
1B),
pounds
per
semiannual
period"

The
commenter
also
requested
verification
that
the
following
"
hypothetical
scenario"
at
"
Mill
A"

is
a
valid
example
of
how
emissions
averaging
can
be
applied:

A
rotary
green
dryer
is
the
only
available
debit
generating
source
at
Mill
A.
Initial
performance
testing
determines
that
this
dryer
has
an
emission
rate
of
5.0
pounds
of
uncontrolled
total
HAP/
hr.
At
Mill
A,
the
average
operating
schedule
for
this
dryer
is
4,000
hours
over
a
6­
month
period.

From
Equation
1:
RMR
=
0.90
x
(
5.0
lb/
hr
x
4,000hr/
6
mo)
=
18,000lb/
6
mo
Mill
A
decides
to
control
20
percent
of
the
green
dryer
emissions
and
finds
a
cost
effective
means
to
achieve
80
percent
control
efficiency
for
the
emissions
from
the
blender.
Initial
performance
testing
indicates
that
the
blender
emits
8
lb/
hr
of
uncontrolled
total
HAP.
The
blender
operates
3,800
hours
over
a
6
month
period.

From
Equation
2:
AMR
=
(
0.20
x
5.0
lb/
hr
x
4,000hr/
6
mo)
+
(
0.80
x
8.0
lb/
hr
x
3,800hr/
6
mo)
=
28,320
lb/
6
mo
Under
this
scenario,
the
emissions
averaging
compliance
option
would
allow
Mill
A
to
undercontrol
the
emissions
from
both
the
rotary
green
dryer
and
the
blender
to
match
the
RMR
value.

Response:
We
agree
with
the
changes
suggested
by
the
commenter.
The
suggested
changes
further
clarify
that
a
process
unit
can
sometimes
be
both
a
debit­
generating
source
and
a
credit­
generating
source
when
that
source
is
undercontrolled
(
e.
g.,
emissions
reduced
by
less
than
90
percent).
In
the
example
provided
by
the
commenter,
the
green
dryer
is
both
a
debitgenerating
unit
and
a
credit­
generating
unit,
and
thus
the
uncontrolled
emissions
from
the
green
dryer
are
accounted
for
in
the
calculations
of
both
the
actual
mass
removal
(
AMR)
and
the
RMR.

We
agree
that
the
example
provided
by
the
commenter
is
an
appropriate
use
of
the
emissions
averaging
compliance
option.

2.6.5
Concentration­
based
applicability
criteria
2.6.5.1
Comment:
Commenter
IV­
D­
27
requested
that,
if
EPA
decides
not
to
adopt
the
risk­
based
approaches
recommended
by
the
commenter
(
see
also
section
2.11
of
this
document),

then
the
final
rule
should
include
a
50
ppm
applicability
criteria
for
the
total
HAP
emitted
by
the
2­
142
regulated
sources.
The
commenter
stated
that
this
approach
is
fully
justified
under
the
CAA
and
applicable
case
law
and
"
holds
great
promise
in
focusing
the
rule
on
eliminating
meaningful
risks
without
giving
rise
to
offsetting
environmental
disbenefits."
The
commenter
stated
that
the
50
ppm
applicability
criteria
could
be
incorporated
into
the
final
rule
by
adding
a
definition
of
process
vent
that
would
specifically
exclude
emission
streams
with
total
HAP
concentrations
below
50
ppm,
as
follows:

"
Process
Vent
means
emission
streams
that
are
undiluted
and
uncontrolled
containing
less
than
50
ppmv
total
HAP,
as
determined
through
process
knowledge
that
no
HAP
are
present
in
the
emission
stream
or
using
an
engineering
assessment
as
discussed
in
Sec.
63.___,
test
data
using
Methods
18
of
40
CFR
part
60,
appendix
A,
or
any
other
test
method
that
has
been
validated
according
to
the
procedures
in
Method
301
of
appendix
A
of
this
part,
are
not
considered
process
vents.

Total
HAP
means
the
sum
of
the
concentrations
of
one
or
more
of
the
following
six
compounds:
acetaldehyde,
acrolein,
formaldehyde,
methanol,
phenol,
and
propionaldehyde."

The
exhaust
stream
would
be
excluded
from
MACT
applicability
so
long
as
its
HAP
content
remained
below
the
50
ppm
concentration
level.
The
commenter
acknowledged
that
steps
would
have
to
be
taken
to
prevent
purposeful
dilution
of
exhaust
streams
if
EPA
adopted
the
concentration­
based
applicability
criteria;
the
commenter
suggested
that
requiring
permit
limits
on
exhaust
stream
flow
rate
may
be
a
possible
solution.

The
commenter
asserted
that
EPA
has
implemented
similar
concentration­
based
applicability
criteria
on
several
occasions
through
the
definition
and
applicability
provisions
of
NESHAP.
The
commenter
pointed
to
the
HON,
which
requires
"
Group
2"
process
vents
to
be
controlled,
while
defining
a
separate
category,
"
Group
2"
process
vents,
that
do
not
require
control
(
59
FR
19402,
19406
[
April
22,
1994]).

The
commenter
noted
that
the
HON
contains
a
50
ppm
cutoff
in
the
process
vent
definition
as
follows:

A
Group
2
process
vent
is
defined
as
a
process
vent
with
a
flow
rate
greater
than
or
equal
to
0.005
scmm,
an
organic
HAP
concentration
greater
than
or
equal
to
50
ppmv,
and
a
TRE
index
value
less
than
or
equal
to
1.0.

The
commenter
also
noted
that,
including
the
HON,
there
are
at
least
twelve
NESHAP
promulgated
since
1994
that
contain
applicability
provisions
that
focus
the
control
requirements
2­
143
on
emissions
streams
above
certain
HAP
concentrations.
The
commenter
provided
a
summary
of
the
applicability
criteria
for
these
12
NESHAP;
this
information
is
shown
in
Table
2­
5.
The
commenter
claimed
that,
given
the
information
provided
in
Table
2­
5,
EPA's
authority
to
set
concentration­
based
applicability
criteria
"
appears
to
be
established
beyond
question."
The
commenter
asserted
that
the
authority
to
set
concentration­
based
applicability
criteria
is
inherent
in
EPA's
authority
to
exclude
de
minimis
emission
sources
from
regulatory
requirements.
The
commenter
further
stated
that
the
D.
C.
Circuit
case
law
has
established
that,
unless
the
governing
statute
is
"
extraordinarily
rigid,"
EPA
has
presumptive
de
minimis
authority
in
implementing
its
regulatory
mandate.
According
to
the
commenter,
the
statutory
design
and
legislative
purpose
expressed
in
CAA
§
112
demonstrate
that
the
statute
is
not
extraordinarily
rigid
so
that
EPA
is
fully
justified
in
applying
its
de
minimis
authority.
The
commenter
also
claimed
that,
even
though
EPA
referred
to
concentration­
based
applicability
critieria
as
"
de
minimis
cutoffs"
in
a
number
of
NESHAP,
EPA
did
not
consider
an
explicit
explanation
of
the
Agency's
de
minimis
legal
authority
to
be
necessary
in
these
rules,
and
there
were
no
apparent
legal
challenges.

Table
2­
5.
NESHAP
with
Concentration­
Based
Applicability
Cutoffs
NESHAP
(
40
C.
F.
R.
Part
63)
SOURCE
OF
EMISSIONS
CONCENTRATION
CUTOFF
ADDITIONAL
CRITERIA
Synthetic
Organic
Chemical
Manufacturing
(
Subpart
F,
§
63.101)
Process
Vent
0.005
weight­
percent
TOC
(

50
ppm)
None
Synthetic
Organic
Chemical
Manufacturing:
Process
Vents,
Storage
Vessels,
Transfer
Operations
and
Wastewater
(
Subpart
G,
§
63.111)
Process
Vent
50
ppmv
TOC
Waiver
of
control
requirements
also
applies
(
regardless
of
concentration
of
vent
stream)
if
flow
rate
is
less
than
0.005
m3
per
minute
or
"
total
resource
effectiveness
index"
is
greater
than
1.0.

Organic
HAP
from
Equipment
Leaks
(
Subpart
H,
§
63.161)
Equipment
containing
or
coming
into
contact
with
HAP
5
percent
TOC
by
weight
(

50,000
ppm)
None
Group
I
Polymers
and
Resins
(
Subpart
U,
§
63.482)
Process
Vent
50
ppmv
TOC
Waiver
of
control
requirements
also
applies
(
regardless
of
concentration
of
vent
stream)
if
flow
rate
is
less
than
0.005
m3
per
minute
or
"
total
resource
effectiveness
index"
is
greater
than
1.0.
Table
2­
5
(
continued)

NESHAP
(
40
C.
F.
R.
Part
63)
SOURCE
OF
EMISSIONS
CONCENTRATION
CUTOFF
ADDITIONAL
CRITERIA
2­
144
Petroleum
Refineries
(
Subpart
CC,
§
63.641)
Process
Vent
20
ppmv
measured
as
choice
of
organic
HAP
or
TOCs
Also
mass­
based
exclusions
(
Total
THC
emissions
of
no
more
than
33
kg
per
day
for
existing
[
6.8
kg
for
new]
sources
prior
to
reaching
any
control
device
and
prior
to
discharge)

Aerospace
(
Subpart
GG,
§
63.742)
Primers,
Topcoats,
Chemical
Milling
Maskants,
Strippers,
and
Cleaning
Solvents
HAP
and
THC
content
of
0.1
percent
for
carcinogens
and
1.0
percent
for
noncarcinogens
None
Equipment
Leaks
 
Control
Level
1
(
Subpart
TT,
§
63.1001)
Equipment
containing
or
coming
into
contact
with
HAP
5
percent
TOC
by
weight
None
Pharmaceuticals
(
Subpart
GGG,
§
63.1251)
Halogenated
vent
stream
20
ppmv
None
Process
Vent
50
ppmv
Undiluted
and
uncontrolled
Flexible
Polyurethane
Foam
Production
(
Subpart
III,
§
63.1292)
HAP­
based
process
chemicals
in
certain
applications
Prohibited
above
5
percent
weight
control
None
Pesticide
Production
(
Subpart
MMM,
§
63.1361)
Process
Vent
20
ppmv
Also
mass­
based
waiver
of
control
requirements
(
organic
HAP
emissions
from
all
process
vents
less
than
0.15
Mg/
yr
and
the
uncontrolled
HCl
and
chlorine
emissions
from
the
sum
of
all
process
vents
less
than
6.8
Mg/
yr.)

Manufacture
of
Amino/
Phenolic
Resins
(
Subpart
OOO,
§
63.1402)
Process
Vent
50
ppmv
organic
HAP
Undiluted
and
uncontrolled
Polyether
Polyols
Production
(
Subpart
PPP,
§
63.1423)
Process
Vent
(
continuous
unit)
0.005
weight
percent
TOC
(

50
ppm)
Waiver
of
control
requirements
also
applies
(
regardless
of
concentration
of
vent
stream)
if
flow
rate
is
less
than
0.005
m3
per
minute
or
"
total
resource
effectiveness
index"
is
greater
than
1.0.

The
commenter
also
noted
that
in
a
number
of
NESHAP,
EPA
has
explained
the
rationale
behind
concentration­
based
applicability
criteria
in
terms
of
control
efficiency,
and
included
the
2­
145
concept
of
a
"
total
resource
effectiveness
[
TRE]
index"
as
a
supplemental
basis
for
exemption
from
control
requirements.
The
commenter
pointed
to
the
definition
of
TRE
as
follows:

Total
resource
effectiveness
index
value
or
TRE
index
value
means
a
measure
of
the
supplemental
total
resource
requirement
per
unit
reduction
of
organic
HAP
associated
with
a
continuous
front­
end
process
vent
stream,
based
on
vent
stream
flow
rate,
emission
rate
of
organic
HAP,
net
heating
value,
and
corrosion
properties
(
whether
or
not
the
continuous
front­
end
process
vent
stream
contains
halogenated
compounds)
(
reference:
65
Fed.
Reg.
38030,
38048
[
June
19,
2000]
[
National
Emission
Standards
for
Hazardous
Air
Pollutants:
Group
I
Polymers
and
Resins]).

According
to
the
commenter,
the
TRE
index
is
a
measure
of
the
efficiency
of
controlling
a
particular
HAP
stream
in
terms
of
energy
and
other
resource
requirements
compared
to
the
amount
of
HAP
reduced.
The
commenter
contended
that
focusing
the
applicability
of
control
requirements
on
the
basis
of
control
efficiency
is
particularly
appropriate
with
respect
to
low­
concentration
HAP
streams
from
the
wood
products
industry
because
the
energy
use
of
a
thermal
oxidizer
is
particularly
high
as
compared
to
the
amount
of
HAP
reduced
when
applied
to
a
low­
rather
than
a
high­
concentration
emissions
stream.

Other
commenters
(
IV­
D­
11
and
IV­
D­
26)
objected
to
the
concept
of
a
concentration­
based
applicability
cutoff,
stating
that
such
a
cutoff
is
not
what
Congress
intended
in
the
CAAA.
Commenter
IV­
D­
26
argued
that
a
concentration­
based
applicability
cutoff
would
be
unlawful
because
it
would
replace
the
MACT
emission
limitation
with
one
that
places
no
limit
on
the
mass
emission
rate.
Commenter
IV­
D­
26
stated
that
the
concentration
of
HAP
in
a
source's
exhaust
steam
has
no
bearing
on
whether
that
source
is
meeting
the
emissions
limitation.

The
commenter
referred
to
language
in
the
preamble
to
the
final
Brick
and
Structural
Clay
Products
(
BSCP)
NESHAP
which
states
that
exhaust
gas
concentrations
have
no
effect
on
mass
emissions
rates,
and
that
mass
emission
rates
are
unchanged
regardless
of
how
much
dilution
air
is
added
(
68
FR
26690
at
26713,
May
16,
2003).
The
commenter
also
claimed
that
EPA
has
already
rejected,
in
prior
actions,
the
idea
that
de
minimis
exceptions
are
available
in
the
way
proposed
by
the
PCWP
industry.

Response:
We
disagree
with
the
request
from
commenter
IV­
D­
27
for
a
concentrationbased
applicability
cutoff
for
several
reasons.
First,
as
shown
in
Table
2­
6,
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
the
commenters
as
precedents
for
2­
146
the
concentration­
based
applicability
exemption,
and
thus
it
would
not
be
appropriate
to
"
borrow"

concentration
cutoffs
from
these
other
rules.
Second,
and
more
importantly,
when
establishing
applicability
cutoffs
for
NESHAP,
we
must
evaluate
these
cutoffs
in
concert
with
the
MACT
floor
analysis.
To
support
the
inclusion
of
a
50
ppmv
cutoff
or
an
alternative
cutoff,
we
would
have
to
clearly
demonstrate
that
the
cut­
off
levels
do
not
exempt
emission
volumes
that
are
otherwise
caught
by
the
MACT
floor.
The
50
ppmv
concentration­
based
applicability
cutoff
proposed
by
the
commenters
does
not
meet
this
criterion
because
it
would
exempt
many
process
units
that
otherwise
would
be
subject
to
MACT
floor
controls.
As
shown
in
Table
2­
7,
a
number
of
PCWP
process
units
equipped
with
MACT
controls
that
have
been
tested
by
the
industry
have
uncontrolled
emission
streams
with
concentrations
less
than
50
ppmv.
Third,
a
50
ppmv
cutoff
would
exempt
the
majority
of
process
units
in
the
PCWP
industry
from
regulation,
despite
the
fact
that
many
of
these
process
units
are
by
themselves
"
major
sources,"
and
therefore
by
definition
are
not
de
minimis.
When
the
50
ppmv
cutoffs
were
applied
in
other
NESHAP,
the
affected
emission
streams
had
much
lower
flow
rates
(
e.
g.,
100
scfm),
and
the
assumption
was
that
such
sources
had
only
minimal
emissions
that
were
below
levels
that
would
be
regulated
by
the
applicable
MACT
floor.
For
example,
the
estimated
average
HAP
emissions
from
a
process
vent
exempted
from
the
Pharmaceuticals
NESHAP
is
88
pounds
per
year.
This
would
not
be
the
case
with
wood
products
plants
because
of
the
higher
flow
rates.
Table
2­
8
shows
the
effect
of
higher
flow
rates
on
the
mass
emissions
of
HAP
at
the
same
concentration
(
50
ppmv).
As
shown
in
Table
2­
8,
at
a
flow
rate
of
20,000
dscfm,
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.

Many
PCWP
process
units
have
flow
rates
greater
than
20,000
dscfm,
and
therefore,
the
mass
of
HAP
associated
with
a
50
ppmv
stream
can
be
even
greater.
For
these
reasons,
the
final
PCWP
rule
does
not
include
a
concentration­
based
applicability
cut­
off.
Additional
details
of
our
analysis
of
the
concentration­
based
applicability
exemptions
is
provided
in
a
separate
memorandum.
25
2­
147
Table
2­
6.
Comparison
of
Emission
Sources25
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
Table
2­
7.
Summary
of
NCASI
Data25
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.
2­
148
Table
2­
8.
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.

We
disagree
with
the
commenters
who
claimed
that
the
requested
concentration­
based
applicability
exemption
can
be
justified
by
de
minimis
principles.
Our
de
minimis
authority
exists
to
help
avoid
excessive
regulation
of
tiny
amounts
of
pollutants,
where
regulation
would
yield
a
result
contrary
to
a
primary
legislative
goal.
It
is
unavailable
"
where
the
regulatory
function
does
provide
benefits,
in
the
sense
of
furthering
the
regulatory
objectives,
but
the
agency
concludes
that
the
acknowledged
benefits
are
exceeded
by
the
costs."
EDF
v.
EPA,
82
F.
3d
451,
466
(
D.
C.

Cir.
1996);
Public
Citizen
v.
Young,
831
F.
2d
1108,
1112­
13
(
D.
C.
Cir.
1987);
Alabama
Power
v.
EPA,
636
F.
2d
323,
360­
61
&
n.
89
(
D.
C.
Cir.
1979).
Accordingly,
a
de
minimis
exemption
to
section
112(
d)(
3)
is
unavailable
in
this
PCWP
MACT
standard,
because
it
would
frustrate
a
primary
legislative
goal
by
carving
out
tons
of
PCWP
sources'
HAP
emissions
from
regulation.

Our
rejection
of
the
de
minimis
concept
in
the
MACT
context
has
already
been
affirmed
by
the
U.
S.
Court
of
Appeals
for
the
District
of
Columbia
Circuit,
in
National
Lime
Ass'n
v.
EPA,

233
F.
3d
625,
640
(
D.
C.
Cir.
2000)
("
NLA"),
in
which
the
court
rejected
the
industry
petitioner's
claim
that
in
light
of
both
the
high
costs
and
low
quantities
of
HAP
at
issue
in
that
case,
we
should
read
a
de
minimis
exception
into
the
requirement
that
we
regulate
all
HAP
emitted
by
major
sources.
In
that
case,
the
Court
found
that
"
EPA
reasonably
rejected
this
argument
on
the
ground
that
the
statute
`
does
not
provide
for
exceptions
from
emissions
standards
based
on
de
minimis
principles
where
a
MACT
floor
exists.'"
NLA
at
640.
We
recently
re­
affirmed
our
position
on
the
unavailability
of
de
minimis
exemptions
from
the
MACT
floor
in
its
final
NESHAP
regulating
organic
liquids
distribution.
See
63
Fed.
Reg.
5048
and
5049
(
February
3,
2004).

Contrary
to
the
commenter's
request,
we
see
no
reason
to
revisit
this
fundamental
issue,

and
reject
the
assertion
that
both
EPA
and
the
court
decided
this
issue
incorrectly
in
NLA.
2­
149
Section
112
of
the
CAA
is
replete
with
careful
definitions
of
volume­
or
effect­
based
limitation
on
regulation,
indicating
that
Congress
has
already
defined
what
amounts
of
HAP
emissions
are
too
small
to
warrant
MACT
standards.
The
requirement
to
adopt
MACT
emission
limitations,
for
example,
applies
without
exception
to
"
each
category
or
subcategory
of
major
sources
.
.
.
of
[
HAP]."
CAA
section
112(
d)(
1).
For
sources
below
the
major
source
threshold,
however,
we
have
discretion
to
require
"
generally
available
control
technologies
or
management
practices."

CAA
section
112(
d)(
5).
Congress
has
thus
itself
defined
volumetrically
which
sources'
emissions
are
small
enough
not
to
warrant
mandatory
MACT
standards.

Congress
likewise
defined
several
MACT
exceptions
applicable
where
emissions
have
de
minimis
health
effects.
Section
112(
d)(
4)
of
the
CAA
allows
us
to
establish
standards
less
stringent
than
MACT
for
HAP
with
an
established
health
threshold,
so
long
as
we
set
a
standard
below
the
health
threshold
with
"
an
ample
margin
of
safety."
Section
112(
b)(
3)(
C)
of
the
CAA
directs
us
to
de­
list
HAP
 
precluding
section
112(
d)
MACT
standards
 
if
we
determine
that
"
there
is
adequate
data
on
the
health
and
environmental
effects
of
the
substance
to
determine
that
emissions,
ambient
concentrations,
bioaccumulation
or
deposition
of
the
substance
may
not
reasonably
be
anticipated
to
cause
any
adverse
effects
to
the
[
sic]
human
health
or
adverse
environmental
effects."
Section
112(
c)(
9)(
B)(
i)
of
the
CAA
lets
us
delete
source
categories
from
the
category
list
 
the
consequence
again
being
no
MACT
control
 
if
we
determine
that,
for
emissions
of
carcinogenic
HAP,
"
no
source
in
the
category
.
.
.
emits
such
[
HAP]
in
quantities
which
may
cause
a
lifetime
risk
of
cancer
greater
than
one
in
one
million
to
the
individual
in
the
population
who
is
most
exposed
to
emissions
of
such
pollutant
from
the
source."
For
noncarcinogens,
we
may
delete
source
categories
if
we
determine
that
"
emissions
from
no
source
in
the
category
or
subcategory
.
.
.
exceed
a
level
which
is
adequate
to
protect
public
health
with
an
ample
margin
of
safety
and
no
adverse
environmental
effect
will
result
from
emissions
from
any
source."
CAA
section
112(
c)(
9)(
B)(
ii).
Moreover,
in
defining
which
source
modifications
trigger
additional
regulatory
standards,
CAA
section
112(
g)(
1)(
A)
mentions
a
"
greater
than
de
minimis
increase
in
actual
emission
of
a
[
HAP]."
This
shows
that
Congress
knew
how
to
use
the
de
minimis
concept
when
it
considered
such
was
appropriate
in
section
112,
and
the
fact
that
it
did
not
use
it
in
section
112(
d)(
3)
supports
our
 
and
the
D.
C.
Circuit's
 
conclusion
that
it
is
unavailable
to
support
an
exception
to
a
MACT
floor.
2­
150
We
do
not
find
persuasive
the
proposition
by
commenter
IV­
D­
27
that
the
overall
purpose
of
section
112
is
protecting
human
health
and
the
environment,
and
that,
therefore,
as
long
as
this
general
purpose
is
met,
we
may
fashion
de
minimis
exceptions
from
MACT.
First,
this
position
appears
to
assume
that
the
issue
is
to
be
drawn
on
a
clean
slate,
while
the
D.
C.
Circuit
has
affirmed
our
view
that
section
112(
d)(
3)
provides
no
discretion
to
use
a
de
minimis
rationale
to
avoid
MACT.
Second,
the
commenter
appears
to
give
prominence
to
an
over­
arching
statutory
goal
over
the
specific
language
of
the
statutory
provisions
themselves,
in
assessing
whether
those
provisions
are
"
extraordinarily
rigid"
regarding
our
otherwise­
inherent
de
minimis
authority;
the
logical
extension
of
such
an
approach
would
be
to
find
that
no
single
provision
in
the
CAA
could
restrict
our
de
minimis
authority,
in
light
of
the
CAA's
over­
arching
purpose
"
to
promote
the
public
health
and
welfare."
CAA
section
101(
b)(
1).
Third,
the
commenter
does
not
present
any
persuasive
statutory
arguments
to
overcome
those
that
we
presented
to
the
court
 
and
which
the
court
affirmed
 
in
NLA.
Fourth,
we
are
unable
to
discern
the
basis
for
the
commenter's
suggestion
that
we
have
in
fact
been
relying
on
de
minimis
authority
in
the
MACT
program
for
several
years
in
establishing
applicability
thresholds,
and
are
not
aware
of
any
instance
in
which
we
have
explicitly
created
such
an
exception
from
an
identified
MACT
floor.
Finally,
to
the
extent
the
commenters
believe
such
a
de
minimis
exemption
is
justified
by
the
wish
to
reduce
the
costs
of
the
PCWP
MACT
rule,
we
are
not
free
to
grant
a
de
minimis
exemption
to
account
for
costs:
Congress
already
took
cost
into
account
in
section
112(
d),
relying
on
prior
business
judgments
by
the
best
performing
sources
to
substitute
for
the
judgment
of
the
rest
of
the
PCWP
industry,
therefore
denying
us
the
leeway
to
consider
costs
as
a
factor
to
modify
the
MACT
floor.

Only
in
considering
more
stringent
"
beyond
floor"
standards
may
we
consider
costs
in
the
MACT
context.
Therefore,
we
do
not
believe
it
is
appropriate
or
necessary
to
revisit
the
Agency's
and
the
D.
C.
Circuit's
prior
conclusions
regarding
the
availability
of
the
de
minimis
principle
in
the
final
PCWP
NESHAP.
We
also
note
that
even
if
reliance
upon
a
de
minimis
theory
were
not
precluded
under
section
112(
d),
in
light
of
the
relatively
high
flow
rates
of
PCWP
process
units,

some
of
which
would
be
major
sources
on
their
own
while
complying
with
a
50
ppmv
cutoff,
it
would
be
impossible
to
find
that
subjecting
these
units
to
the
MACT
floor
would
yield
a
gain
of
"
trivial
or
no
value."
2­
151
2.7
TESTING
AND
MONITORING
REQUIREMENTS
2.7.1.
Emission
measurement
test
methods
2.7.1.1
Comment:
Commenters
IV­
D­
20
and
IV­
D­
27
supported
the
inclusion
of
NCASI
test
methods
in
the
proposed
PCWP
rule,
but
recommended
that
EPA
replace
NCASI
Method
IM/
CAN/
WP­
99.01
with
the
revised
version
of
the
same
method.
Commenter
IV­
D­
20
provided
a
revised
version
of
NCASI
IM/
CAN/
WP­
99.01
(
which
was
later
renumbered
as
NCASI
IM/
CAN/
WP­
99.02),
noting
that
the
trained
NCASI
sample
team
was
able
to
get
good
consistent
results
with
the
original
version
of
the
method
both
in
the
laboratory
and
the
field,
but
that
sampling
contractors
had
difficulty
obtaining
valid
results.
Commenter
IV­
D­
20
maintained
that
the
revised
version
is
easier
to
understand,
is
more
complete
in
detail,
provides
a
better
standard
for
the
impinger/
canister
method,
and
reflects
the
comments
of
the
contractors
that
have
experience
with
the
original
method;
the
quality
assurance
requirements
were
also
strengthened
to
ensure
good
results.

Another
commenter
(
IV­
D­
04)
stated
that
their
experience
with
the
NCASI
Method
CI/
WP­
98.01
(
proposed
for
measurement
of
methanol
and
formaldehyde)
showed
that
sampling
stack
emissions
with
a
high
moisture
content
would
require
a
large
impinger,
isokinetic
version
of
this
method
to
ensure
accuracy.
Therefore,
this
commenter
requested
that
EPA
add
guidance
in
the
final
rule
to
allow
the
use
of
the
isokinetic
version
of
the
NCASI
method
when
needed.

Commenter
IV­
D­
27
also
noted
that
NCASI
Method
DI/
MEOH­
94.02
has
been
revised
and
is
now
NCASI
Method
DI/
MEOH­
94.03.
The
more
recent
version
of
this
method
should
be
included
in
the
PCWP
rule.

Response:
The
final
PCWP
rule
references
the
most
recent
version
of
NCASI
Method
IM/
CAN/
WP­
99.02,
as
requested
by
the
commenter.
Regarding
the
revised
version
of
NCASI
Method
DI/
MEOH­
94.02,
this
method
does
not
apply
to
this
rulemaking,
and
therefore,
we
did
not
update
references
to
this
method
in
the
General
Provisions
(
40
CFR
Part
63.14)
as
part
of
this
rulemaking.
Regarding
one
commenter's
request
to
allow
the
use
of
a
"
large
impinger,
isokinetic
version"
of
NCASI
Method
CI/
WP­
98.01
for
stack
emissions
with
high
moisture
content,
we
note
that
such
a
version
does
not
exist.
We
also
note
that
the
majority
of
the
HAP
data
used
in
the
development
of
the
PCWP
rule
was
collected
using
NCASI
Method
CI/
WP­
98.01
as
is.

Someone
would
have
to
develop
and
validate
an
alternative
large
impinger,
isokinetic
version
of
2­
152
NCASI
Method
CI/
WP­
98.01
before
such
a
method
could
be
included
in
the
PCWP
rule.

Therefore,
the
final
rule
does
not
include
an
alternative
version
of
NCASI
Method
CI/
WP­
98.01.

2.7.1.2
Comment:
Commenter
IV­
D­
27
supported
the
variety
of
choices
given
for
measurements
and
methods
in
Table
4
to
proposed
subpart
DDDD.
The
commenter
stated
that
having
multiple
testing
options
will
allow
facilities
and
sampling
contractors
to
choose
the
method
that
best
fits
their
needs
and
application.
The
commenter
contended
that
EPA
should
also
give
PCWP
facilities
the
option
to
use
future
methods
once
they
have
been
reviewed
by
EPA
and
have
passed
Method
301
validation
at
a
PCWP
plant.
The
commenter
noted
that
NCASI
is
currently
developing
a
method
for
measuring
the
six
HAP
("
total
HAP")
listed
in
the
PCWP
rule.
Although
this
new
method
probably
will
be
field
validated
via
EPA
Method
301
procedures,
it
will
not
be
eligible
for
alternate
method
approval
by
EPA,
since
a
primary
method
that
has
been
validated
at
PCWP
sources
does
not
exist.
The
commenter
stated
that
a
change
to
Table
4
to
subpart
DDDD
could
rectify
that
situation.

Response:
As
discussed
in
the
preamble
to
the
final
PCWP
rule,
if
and
when
a
new
method
for
measuring
HAP
from
PCWP
sources
is
developed
and
validated
via
EPA
Method
301,
we
will
issue
an
amendment
to
the
final
rule
to
include
the
use
of
that
method
as
an
alternative
to
the
methods
included
in
the
final
rule
for
measuring
total
HAP
(
i.
e.,
NCASI
Method
IM/
CAN/
WP/
99.02
and
EPA
Method
320­­
Measurement
of
Vapor
Phase
Organic
and
Inorganic
Emission
by
Extractive
FTIR).
In
the
meantime,
if
the
new
method
is
validated
using
Method
301,
then
the
Method
301
results
can
be
used
to
request
approval
to
use
the
new
method
on
a
site­
specific
basis.

2.7.1.3
Comment:
Commenter
IV­
D­
27
supported
the
use
of
Method
25A
for
measuring
THC
as
carbon
and
Method
18
for
measuring
methane
for
the
purpose
of
subtracting
methane
from
THC
concentration.
Commenter
IV­
D­
03
requested
that
other
compounds
such
as
acetone
be
added
to
the
exempt
compound
list
so
that
they
can
be
quantified
and
subtracted
from
Method
25A
results.

Response:
We
allowed
sources
to
subtract
methane
from
the
THC
values
measured
using
EPA
Method
25A
for
two
reasons.
The
first
reason
is
that
a
number
of
PCWP
facilities
equipped
with
MACT­
level
controls
installed
these
controls
to
reduce
VOC
emissions,
and
these
facilities
are
allowed
to
subtract
methane
emissions
from
the
THC
measurement
when
reporting
VOC
emissions
because
methane
is
not
a
VOC
according
to
EPA's
definition
of
VOC.
The
second
2­
153
reason
is
that
we
accounted
for
the
effects
of
methane
emissions
when
setting
the
outlet
THC
emission
level
at
20
ppm
and
the
percent
reduction
of
THC
at
90
percent
as
part
of
the
development
of
the
compliance
options
for
add­
on
control
systems.
We
do
not
have
data
on
emissions
of
other
compounds
excluded
from
the
definition
of
VOC
(
such
as
acetone)
that
may
be
emitted
from
PCWP
process
units,
and
thus,
we
do
not
know
how
subtraction
of
these
compounds
would
affect
our
prior
determinations.
Also,
it
is
important
to
note
that
the
PCWP
rule
is
not
a
VOC
rule
and
THC
is
only
used
as
a
surrogate
in
the
final
PCWP
rule
as
a
means
of
assessing
HAP
emissions
control
device
performance.
If
sources
need
to
calculate
total
VOC
emissions
to
demonstrate
compliance
with
VOC
emission
limits,
then
they
can
subtract
these
other
compounds
for
that
purpose;
however,
for
the
purpose
of
complying
with
PCWP
MACT,

sources
must
follow
the
procedures
in
the
PCWP
final
rule
for
determining
the
THC
emission
reduction
or
outlet
THC
concentration,
depending
upon
which
option
they
choose.

2.7.1.4
Comment:
Commenter
IV­
D­
19
supported
the
use
of
one­
half
detection
limits
for
nondetect
HAP
to
an
extent,
but
not
in
every
case.
The
commenter
noted
that,
if
a
test
shows
a
HAP
to
be
below
the
detection
limit
but
the
number
of
"
hits"
is
statistically
significant,
then
using
the
one­
half
detection
limit
is
valid,
provided
the
sample
is
a
true
representation
of
the
system.

However,
in
some
cases,
the
one­
half
detection
limit
is
used
when
only
one
point
in
one
set
of
data
provides
evidence
that
a
HAP
exists
for
that
process
unit.
The
commenter
contended
that
EPA
should
consider
alternatives
for
these
types
of
situations.
The
commenter
also
stated
that,

"
any
presumption
of
one­
half
detection
limits
based
on
emission
factor
data
should
be
a
rebuttable
presumption
which
could
be
remedied
by
site­
specific
acquisition
of
a
statistically
significant
number
of
determinations."
Commenter
IV­
D­
21
requested
that
nondetect
data
not
be
"
arbitrarily"
treated
as
one­
half
detection
limit,
and
stated
that
"
EPA
should
provide
for
consistent
handling
of
non­
detect
data
throughout
the
rule."

Response:
The
final
rule
requires
PCWP
facilities
to
treat
all
nondetect
HAP
measurements
as
being
equal
to
one­
half
the
detection
limit,
with
one
exception,
as
explained
previously
in
Section
2.6.3.1
of
this
document.
When
a
PCWP
facility
measures
uncontrolled
HAP
emissions
to
demonstrate
compliance
with
the
PBCO,
the
facility
may
treat
the
emissions
of
an
individual
HAP
as
being
zero
if
all
three
test
runs
yielded
a
nondetect
measurement
and
the
detection
limit
was
set
at
less
than
or
equal
to
1
ppm.
2­
154
2.7.2
Capture
efficiency
test
methods
2.7.2.1
Comment:
Commenter
IV­
D­
03
argued
that
the
use
of
methods
other
than
Method
204
and
the
tracer
gas
method
should
be
allowed
for
determining
capture
efficiency.
The
commenter
noted
that
the
press
emissions
from
their
facility
are
captured
by
a
canopy
hood
system
designed
to
meet
the
American
Conference
of
Governmental
Industrial
Hygienists
(
ACGIH)
guidelines
and
then
directed
to
a
venturi
scrubber.
The
commenter
requested
that
the
final
rule
allow
their
facility
to
demonstrate
a
95
percent
or
greater
capture
efficiency
by
presenting
the
design
information
to
the
regulatory
authority
for
review
and
approval.

Response:
The
commenter
did
not
provide
any
data
to
confirm
that
a
hood
designed
by
the
ACGIH
design
criteria
actually
achieves
at
least
95
percent
capture
efficiency.
However,
we
would
like
to
note
that
a
facility
is
allowed
to
petition
the
Administrator
for
permission
to
use
any
alternative
methods.
The
commenter
should
be
aware
that
the
Administrator
will
require
evidence
that
meeting
the
ACGIH
design
criteria
allows
the
hood
to
achieve
an
acceptable
capture
efficiency.
The
facility
will
have
to
confirm
the
hood
capture
efficiency
with
a
test
like
the
tracer
gas
method
in
Appendix
A
of
the
final
PCWP
rule.
Alternatively,
appendix
A
to
subpart
KK
to
part
63,
Data
Quality
Objective
and
Lower
Confidence
Limit
Approaches
for
Alternative
Capture
Efficiency
Protocols
and
Test
Methods,
establishes
the
criteria
for
using
alternative
methods
to
demonstrate
capture
efficiency.
Unless
the
facility
confirms
the
hood
capture
efficiency,
the
facility
is
not
likely
to
receive
permission
to
use
the
ACGIH
guidelines
as
an
alternative
method
to
determining
capture
efficiency.

2.7.2.2
Comment:
Commenter
IV­
D­
27
requested
that
the
sampling
period
for
press
vent
enclosure
certification
via
method
204D
be
reduced
from
three
hours
to
no
more
than
one
hour.

The
commenter
stated
that
this
press
test
method
was
developed
for
surface
coating
and
printing
operations,
which
have
much
longer
production
cycles
than
the
hot
presses
used
in
wood
panels
manufacturing.
The
commenter
noted
that
a
batch
cycle
for
a
batch
wood
panel
press
lasts
only
minutes
rather
than
hours,
and
continuous
presses
will
probably
replace
batch
presses
over
time.

Therefore,
the
commenter
recommended
that
the
duration
of
each
test
run
should
be
based
on
the
cycle
time
of
the
individual
press
operation.

Response:
We
decided
not
to
change
the
sampling
period
requirements
in
EPA
Method
204D.
We
do
not
have
data
to
ensure
that
Method
204D
sampling
periods
lasting
only
minutes
would
yield
optimal
results,
especially
given
the
commenter's
assertions
elsewhere
that
press
2­
155
emissions
within
enclosures
may
not
flow
freely
to
the
exhaust
point
in
the
top
of
the
enclosure
(
See
related
comments
in
Section
2.3.2.8
and
2.7.2.4).
We
note
that
section
1.3
of
Method
204D
states
that
the
capture
efficiency
test
must
include
three
sampling
runs,
and
that
"
each
run
shall
cover
at
least
one
complete
production
cycle,
but
shall
be
least
3
hours
long."
The
method
also
states
that,
"
Alternative
sampling
times
may
be
used
with
the
approval
of
the
Administrator."

Therefore,
PCWP
facilities
using
Method
204D
still
have
the
option
of
requesting
alternative
sampling
times
on
a
site­
specific
basis.

In
addition,
we
are
not
compelled
to
change
the
sampling
time
in
EPA
Method
204D
because
PCWP
facilities
are
not
required
to
use
Method
204D.
Facilities
may
use
the
alternative
tracer
gas
method
in
appendix
A
of
the
final
PCWP
rule,
which
requires
only
20­
minute
test
runs.

Also,
appendix
A
to
subpart
KK
to
part
63
(
Data
Quality
Objective
and
Lower
Confidence
Limit
Approaches
for
Alternative
Capture
Efficiency
Protocols
and
Test
Methods)
establishes
the
criteria
for
using
alternative
methods
to
demonstrate
capture
efficiency,
and
this
appendix
states
a
minimum
sampling
time
of
20
minutes
per
run.

2.7.2.3
Comment:
Commenter
IV­
D­
27
supported
EPA's
recognition
of
the
need
for
flexibility
in
determining
capture
efficiency
for
PCWP
press
enclosures
and
inclusion
of
the
tracer
gas
method
as
an
alternative
to
Method
204
in
the
PCWP
rule.
The
commenter
noted
that
the
tracer
gas
method
is
a
"
work
in
progress"
and
included
with
their
comments
a
copy
of
field
validation
tests
conducted
at
a
Georgia­
Pacific
Corporation
OSB
facility.
Commenter
IV­
D­
19
also
submitted
test
results
for
the
tracer
gas
method
as
part
of
their
comments
on
the
proposed
rule.
Commenter
IV­
D­
27
stated
that
two
more
tests
are
scheduled
for
the
second
quarter
of
2003,
one
to
verify
the
Georgia­
Pacific
results
and
the
other
to
determine
the
capture
efficiency
of
a
PTE
at
a
second
OSB
facility.
Commenter
IV­
D­
27
stated
that
the
results
of
these
tests
should
help
EPA
improve
the
use
and
application
of
the
proposed
tracer
gas
test.

Response:
We
have
reviewed
the
results
of
the
first
field
validation
test
of
the
tracer
gas
method,
and
we
note
that
the
commenters
did
not
provide
any
specific
recommendations
for
modifying
the
tracer
gas
method
as
it
was
proposed.
Therefore,
other
than
a
few
minor
wording
changes,
we
did
not
make
any
substantive
changes
to
the
tracer
gas
method
in
the
final
rule.
If
the
results
of
subsequent
field
tests
demonstrate
a
need
to
(
further)
modify
the
tracer
gas
method,

we
will
issue
an
amendment
to
the
final
rule
to
incorporate
the
necessary
changes.
Furthermore,

appendix
A
to
subpart
KK
to
part
63,
Data
Quality
Objective
and
Lower
Confidence
Limit
2­
156
Approaches
for
Alternative
Capture
Efficiency
Protocols
and
Test
Methods,
establishes
the
criteria
for
using
alternative
methods
to
demonstrate
capture
efficiency,
and
this
appendix
would
allow
the
industry
to
submit
a
modified
tracer
protocol
for
approval,
as
long
as
it
met
the
acceptance
criteria
for
an
alternative
procedure.

2.7.2.4
Comment:
Commenters
IV­
D­
19,
IV­
D­
21,
and
IV­
D­
27
recommended
that
the
final
rule
include
work
practice
requirements
in
lieu
of
requiring
EPA
Method
204
certification
for
press
enclosures,
based
on
their
assertion
that
press
enclosures
certified
to
meet
EPA
Method
204
do
not
constitute
the
MACT
floor
for
presses
(
see
previous
discussion
in
Section
2.3
 
Existing
Source
MACT
Floor).
The
commenters
noted
that
the
proposed
PCWP
rule
does
not
require
an
initial
performance
test
for
work
practice
requirements,
so
verification
of
the
capture
efficiency
for
PTEs
should
be
a
one­
time
determination
based
on
satisfying
the
press
enclosure
work
practice
requirements.
The
commenters
stated
that,
for
any
enclosure
that
is
not
a
PTE,
a
facility
should
have
to
determine
the
capture
efficiency
using
the
tracer
gas
method,
Methods
204A
through
204F,
or
alternate
methods
approved
by
the
Administrator.
The
commenters
recommended
the
following
additions
to
Table
6
to
subpart
DDDD
(
Initial
compliance
demonstrations
for
work
practice
requirements):

For
each
.
.
.
For
the
following
work
practice
requirements
.
.
.
You
have
demonstrated
initial
compliance
if
.
.
.

(
5)
Hot
Presses
Minimize
fugitive
emissions
from
the
capture
device
through
appropriate
operation
and
maintenance
procedures
applied
to
PTE
system.
You
meet
the
work
practice
requirements
AND
you
submit
with
the
Notification
of
Compliance
Status
a
copy
of
your
plan
for
minimizing
fugitive
emissions
from
the
capture
device
(
as
required
in
§
63.2267)
2­
157
Also,
commenter
IV­
D­
27
suggested
the
following
additions
to
Table
3
to
subpart
DDDD
to
include
the
new
work
practice
requirements
for
presses:

For
the
following
process
units
at
existing
or
new
affected
sources
.
.
.
You
must
.
.
.

(
5)
Hot
Presses
Install
and
operate
a
capture
device
according
to
the
following:
For
PTEs:
Permanent
Total
Enclosure
(
PTE)
means
a
permanently
installed
containment
that
was
designed
to
meet
the
following
physical
design
criteria:
1.
Any
NDO
shall
be
at
least
four
equivalent
opening
diameters
from
each
THC­
emitting
point
unless
otherwise
specified
by
the
Administrator.
The
MACT
floor
configuration
of
the
PTE
includes
capturing
emissions
from
the
press
unloader.
For
purposes
of
determining
compliance
with
criteria
1,
the
distance
from
the
THCemitting
point
will
be
considered
to
the
press.
2.
The
total
area
of
all
NDOs
shall
not
exceed
5
percent
of
the
surface
area
of
the
enclosure's
four
walls,
floor,
and
ceiling.
3.
The
average
facial
velocity
(
FV)
of
air
through
all
NDOs
shall
be
at
least
3,600
m/
hr
(
200
ft/
min).
The
direction
of
airflow
through
all
NDOs
shall
be
into
the
enclosure.
4.
All
access
doors
and
windows
whose
areas
are
not
included
in
2
and
are
not
included
in
the
calculation
of
FV
in
3
shall
be
closed
during
routine
operation
of
the
process.
5.
Fugitive
emissions
shall
be
minimized
through
appropriate
operation
and
maintenance
procedures
applied
to
the
PTE
system.
If
a
PTE
meets
the
above
criteria,
it
will
meet
the
emissions
capture
requirements
of
the
floor
technology.
The
destruction
efficiency
for
the
captured
emissions
would
be
90
percent.
For
Non­
PTEs:
Existing
and
future
enclosures
that
are
not
PTE,
should
be
required
to
demonstrate
90
percent
capture
and
control
efficiency
using
the
tracer
gas
method
or
some
other
method
subject
to
the
approval
of
the
Administrator,
and
the
appropriate
test
method
for
the
compliance
pollutant.
Any
shortfall
in
capture
could
be
remedied
via
an
emission
averaging
approach
or
through
acceptance
of
a
higher
offsetting
destruction
efficiency
requirement.
2­
158
Commenter
IV­
D­
21
recommended
a
similar
addition,
but
with
some
slight
changes
to
item
1
as
follows:

1.
Any
natural
draft
opening
(
NDO)
shall
be
at
least
four
equivalent
opening
diameters
from
each
VOC­
emitting
point,
except
for
where
mat
enters
the
enclosure
and
the
board
from
the
unloader
exits
the
enclosure,
unless
otherwise
specified
by
the
Administrator.

Finally,
commenter
IV­
D­
27
recommended
the
following
changes
to
Table
4
to
subpart
DDDD
to
reflect
changes
to
performance
test
requirements:

For
.
.
.
You
must
.
.
.
Using
.
.
.

(
9)
Each
reconstituted
wood
products
press
at
a
new
or
existing
affected
source
or
reconstituted
wood
product
board
cooler
at
a
new
affected
source
subject
to
a
compliance
option
in
Table
1B
or
used
in
calculation
of
an
emissions
average
under
§
63.2240(
c).
For
Non­
PTEs
­
Determine
the
percent
capture
efficiency
of
the
enclosure
directing
emissions
to
an
add­
on
control
device.

For
PTEs
­
Determine
the
reduction
in
emissions
or
percent
destruction
efficiency
of
the
control
device.
Methods
204
and
204A
through
204F
(
as
appropriate)
of
40
C.
F.
R.
part
51,
appendix
M.
As
an
alternative
to
Methods
204
and
204A
through
204F,
you
may
use
the
tracer
gas
method
contained
in
appendix
A
to
this
subpart.

Refer
to
(
1)
through
(
8)
of
this
Table
for
the
appropriate
test
method.

Response:
As
discussed
in
response
to
comment
2.3.2.8,
the
final
PCWP
rule
sets
forth
design
criteria
for
wood
products
enclosures.
These
criteria
are
slightly
different
from
the
EPA
Method
204
design
criteria
for
PTEs.
The
final
PCWP
rule
contains
a
definition
of
"
wood
products
enclosure"
which
states
the
design
criteria,
and
a
definition
of
"
partial
wood
products
enclosure"
which
includes
any
enclosure
other
than
a
"
wood
products
enclosure."
Capture
devices
meeting
the
definition
of
"
wood
products
enclosure"
are
assumed,
for
all
practical
purposes,
to
achieve
100
percent
capture
of
emissions.
Because
the
capture
efficiency
of
"
partial
wood
products
enclosures"
is
unknown,
the
final
rule
requires
facilities
to
test
the
capture
efficiency
of
partial
wood
products
enclosures
using
EPA
Methods
204
and
204A­
F
(
as
appropriate),
or
the
alternative
tracer
gas
procedure
included
in
appendix
A
to
subpart
DDDD.

The
final
rule
requires
facilities
using
partial
wood
products
enclosures
to
demonstrate
a
combined
90
percent
capture
and
control
efficiency
for
those
facilities
showing
compliance
with
the
percent
reduction
requirements
for
APCDs.
If
the
partial
wood
products
enclosure
does
not
2­
159
achieve
high
capture
efficiency,
then
facilities
must
offset
the
needed
capture
efficiency
by
achieving
a
higher
destruction
efficiency
or
by
using
emissions
averaging
(
with
the
press
being
an
undercontrolled
process
unit).

The
final
rule
requires
a
one­
time
verification
of
the
capture
efficiency
for
wood
products
enclosures
and
partial
wood
products
enclosures.
To
assume
100
percent
capture
efficiency
using
a
wood
products
enclosure,
facilities
must
submit
with
the
Notification
of
Compliance
Status
documentation
that
the
wood
products
enclosure
meets
the
design
criteria
defined
in
the
rule.
For
partial
wood
products
enclosures,
facilities
must
submit
with
the
Notification
of
Compliance
Status
the
results
of
capture
efficiency
verification
using
EPA
Methods
204
and
204A­
F
(
as
appropriate),
or
the
alternative
tracer
gas
procedure
included
in
appendix
A
to
subpart
DDDD.

Wording
changes
were
made
in
various
places
in
the
proposed
rule
to
incorporate
the
revised
requirements
for
wood
products
enclosures
and
partial
wood
products
enclosures.
These
wording
changes
are
different
from
the
wording
suggested
by
the
commenters
but
accomplish
the
same
purpose
(
i.
e.,
the
design
criteria
are
included
in
the
definitions
but
not
included
as
work
practices).

2.7.3
General
monitoring
2.7.3.1
Comment:
Commenter
IV­
D­
27
noted
that
the
third
column
of
Line
1
in
Table
7
to
subpart
DDDD
currently
states
that
compliance
is
demonstrated
by
"
maintaining
the
average
operating
parameter
at
or
above
the
maximum,
at
or
below
the
minimum."
However,
based
on
the
definitions
of
maximum
and
minimum,
this
phrase
should
be
"
at
or
below
the
maximum,
at
or
above
the
minimum."

Response:
We
agree
with
the
suggested
change
and
have
modified
Table
7
to
subpart
DDDD
in
the
final
rule
as
suggested.

2.7.4
Block
averaging
period
for
operating
requirements
2.7.4.1
Comment:
Commenters
IV­
D­
19,
IV­
D­
21,
and
IV­
D­
27
requested
that
the
proposed
3­
hour
block
averaging
period
specified
by
the
proposed
operating
requirements
be
extended
for
most
of
the
monitoring
parameters.
The
commenters
specifically
recommended
that
the
3­
hour
block
averaging
period
be
extended
to
a
12­
hour
block,
except
as
noted
elsewhere.

The
commenters
noted
that
the
3­
hour
averaging
time
was
selected
by
EPA
because
the
initial
performance
test
requires
three
1­
hour
test
runs,
but
contended
that
this
time
period
is
impractical
for
continuous
monitoring
of
control
device
performance.
The
commenters
stated
that
a
3­
hour
2­
160
block
average
monitoring
requirement
would
increase
monitoring
and
recordkeeping
requirements
without
guaranteeing
compliance
and
would
increase
the
number
of
insignificant
deviations
reported.
The
commenters
argued
that
3
hours
would
not
be
enough
time
in
all
cases
for
operators
and
equipment
to
respond
and
adjust
to
changes
along
the
process
line,
such
as
a
change
in
the
wood
species.
As
an
example,
the
commenters
pointed
to
variation
in
measurements
and
instrumentation
as
another
justification
for
extending
the
block
average.

According
to
the
commenters,
there
can
be
a
large
variation
between
instruments
measuring
a
specific
parameter
at
different
locations
on
a
process
unit
or
control
device.
As
an
example,
the
commenters
pointed
to
the
variation
between
thermocouples
used
to
measure
the
temperature
of
the
RTO
combustion
chamber
and
control
the
burners.
The
commenters
stated
that
the
temperature
reading
will
vary
from
thermocouple
to
thermocouple,
and
the
variation
could
be
as
high
as
50
º
F.
The
commenter
noted
that,
depending
on
the
operating
conditions,
this
variation
could
be
much
lower,
and
a
longer
block­
averaging
time
would
enable
plant
operators
to
get
a
better
sense
of
whether
or
not
a
device
is
actually
within
the
operating
limits.
The
commenters
also
noted
that
some
of
these
problems
could
be
alleviated
by
allowing
the
source
to
establish
an
operating
window
during
compliance
testing
instead
of
being
required
to
operate
at
typical
conditions
during
the
compliance
test
(
see
related
comment
in
Section
2.7.5).
The
commenters
specifically
recommended
recording
data
readings
for
RTOs
and
RCOs
every
15
minutes
and
then
including
all
the
data
in
a
12­
hour
block
average.

The
commenters
further
justified
the
12­
hour
block
average
as
being
consistent
with
industry
practice.
According
to
the
commenters,
several
of
the
consent
decrees
negotiated
between
EPA
and
industry
that
were
included
in
the
MACT
floor
determination
contain
12­
hour
block
average
parameter
monitoring
requirements.
The
commenters
contended
that
the
12­
hour
time
period
in
these
consent
decrees
reflects
the
agreement
between
EPA
and
industry
that
this
longer
time
period
is
adequate
for
monitoring
control
device
performance.

Response:
We
have
decided
to
reduce
the
number
of
control
device
operating
parameters
that
must
be
measured
to
ensure
compliance
with
the
final
rule
(
see
responses
to
comments
in
Sections
2.7.10
through
2.7.14).
In
the
final
PCWP
rule,
temperature
is
the
only
parameter
that
is
required
to
be
continuously
monitored
to
meet
the
operating
requirements
for
the
listed
add­
on
control
devices.
Because
we
have
reduced
the
stringency
of
the
operating
requirements
for
addon
controls
and
because
temperature
is
both
a
controllable
parameter
and
a
reliable
indicator
of
2­
161
control
device
performance,
we
have
decided
to
retain
a
block
averaging
period
of
3
hours.

Regarding
the
comments
related
to
variation
among
thermocouple
readings,
we
agree
that
individual
thermocouple
readings
within
an
RTO
may
vary
by
as
much
as
50

F.
In
a
typical
RTO,

there
are
multiple
combustion
chambers,
each
with
one
or
more
thermocouples.
The
final
rule
clarifies
the
temperature
monitoring
requirements
for
RTOs
to
make
it
clear
that
the
operating
limit
applies
to
the
combined
average
temperature
of
the
thermocouples
in
each
combustion
chamber
rather
than
to
the
temperature
measurement
for
one
individual
thermocouple.
If
there
are
multiple
thermocouples
within
each
combustion
chamber,
we
expect
that
facilities
would
average
the
measurements
from
each
thermocouple
to
provide
a
representative
temperature
for
the
combustion
chamber.
Regarding
consent
decrees
between
EPA
and
wood
products
companies,
we
note
that,
although
some
of
the
companies
are
allowed
to
use
a
12­
hour
block
average,
these
companies
also
are
required
to
monitor
multiple
operating
parameters
(
e.
g.,

temperature,
air
flow,
pressure
drop).

2.7.5
Testing
at
boundary
conditions
2.7.5.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
argued
that
because
the
initial
compliance
tests
determine
the
outer
limits
of
compliance,
those
tests
should
be
performed
at
the
boundaries
of
expected
performance
for
the
process
and
control
units.
The
commenters
noted
that
the
PCWP
rule
currently
requires
testing
at
"
representative"
conditions,
but
only
using
"
representative"
conditions
would
not
accurately
simulate
true
operating
conditions,
and
thus,
the
operating
parameter
limits
would
be
too
narrow.
Therefore,
the
commenters
contended
that
the
rule
should
specify
that
initial
compliance
tests
should
be
conducted
at
the
extremes
of
the
expected
operating
range
for
the
parameter
and
control
device
function.
The
commenters
stated
that
removing
the
requirement
to
test
under
representative
conditions
would
eliminate
the
need
for
facilities
to
explain
why
the
initial
compliance
testing
conditions
are
"
representative,"
and
instead,
facilities
should
be
required
to
explain
why
the
boundary
conditions
chosen
for
testing
are
valid.
In
addition,
commenter
IV­
D­
21
noted
that
this
approach
should
also
address
potential
conflicts
with
traditional
State
requirements
to
test
at
maximum
or
design
conditions.

Response:
Our
definition
of
"
representative
operating
conditions"
refers
to
the
full
range
of
conditions
at
which
the
process
unit
will
be
operating
in
the
future.
We
expect
that
facilities
will
test
a
variety
of
conditions,
including
upper
and/
or
lower
bounds,
to
broaden
their
operating
limit
ranges.
There
are
advantages
to
requiring
performance
testing
at
representative
operating
2­
162
conditions
for
the
PCWP
rule.
Facilities
do
not
routinely
operate
at
maximum
conditions;
two
commenters
pointed
out
(
see
comment
No.
2.7.14.1)
that
maximum
operating
conditions
occur
less
that
5
percent
of
the
time.
Compliance
with
the
PCWP
rule
can
be
achieved
using
a
variety
of
APCD
(
e.
g.,
RTO,
RCO,
biofilter)
or
through
use
of
emissions
averaging
or
PBCOs.
One
reason
we
chose
to
require
representative
conditions
rather
than
maximum
conditions
was
to
ensure
consistency
in
determining
emissions
averaging
credits
and
debits.
In
addition,
operating
parameters
required
to
be
monitored
to
show
compliance
do
not
always
correlate
with
maximum
conditions.
For
example,
commenters
noted
in
comment
2.7.11.1
that
when
the
RCO
inlet
THC
concentration
is
high
(
as
would
be
the
case
for
testing
under
maximum
operating
conditions),
the
RCO
would
operate
at
temperatures
higher
than
the
set
point
during
the
performance
test
and
the
RCO
minimum
temperature
limit
would
be
set
too
high
for
production
rates
less
than
full
capacity.
Requiring
testing
at
representative
operating
conditions
resolves
this
problem.

Furthermore,
as
discussed
in
response
to
comment
No.
2.7.15.1,
for
process
units
without
control
devices,
the
final
PCWP
rule
requires
facilities
to
select
the
process
unit
controlling
operating
parameter(
s)
based
on
representative
operating
conditions;
to
establish
the
operating
limit
for
each
controlling
parameter
as
the
minimum,
maximum,
range,
or
average
(
as
appropriate
depending
on
the
parameter)
recorded
during
the
performance
test(
s);
and
maintain
these
parameters
within
the
ranges
established
during
the
performance
test(
s).
Facilities
operating
biofilters
must
maintain
their
biofilter
bed
temperature
within
the
range
established
during
the
initial
performance
test
and,

if
available,
previous
performance
tests.
If
the
final
PCWP
rule
required
testing
at
maximum
operating
conditions,
then
there
would
be
no
way
for
facilities
to
identify
their
operating
parameter
ranges.
For
these
reasons,
we
maintain
that
the
requirement
to
test
at
representative
operating
conditions
is
appropriate
for
the
PCWP
rule.

2.7.6
Compliance
exemption
during
performance
testing
2.7.6.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
requested
that
EPA
make
an
addition
to
sections
63.2262(
k)(
4)
(
Establishing
thermal
oxidizer
operating
requirements)
and
63.2262(
l)(
4)
(
Establishing
catalytic
oxidizer
operating
requirements)
so
that
facilities
can
avoid
being
in
violation
of
compliance
when
they
are
testing
new
operating
ranges.
Commenter
IV­
D­

27
provided
the
following
sentence
to
be
added
to
the
end
of
the
paragraph
at
(
4):
"
If,
in
attempting
to
expand
the
operating
range
the
required
removals
are
not
attained,
it
does
not
constitute
a
violation
during
the
period
of
the
testing."
Commenter
IV­
D­
21
provided
similar
2­
163
language:
"
If,
in
attempting
to
expand
the
operating
range
the
required
removals
are
not
attained,

said
failure
to
achieve
the
required
removals
shall
not
constitute
a
violation
during
the
period
of
the
testing."

Response:
The
final
rule
does
not
include
the
sentence
requested
by
the
commenter.
We
believe
that
decisions
regarding
whether
or
not
a
violation
has
taken
place
during
the
period
of
testing
should
be
made
if
and
when
such
a
situation
arises
on
a
case­
by­
case
basis.
We
note
that,

in
the
final
PCWP
rule,
temperature
is
the
only
parameter
that
is
required
to
be
continuously
monitored
to
meet
the
operating
requirements
for
thermal
oxidizers
and
catalytic
oxidizers.
When
conducting
tests
to
expand
the
temperature
range
(
e.
g.,
lower
the
minimum
temperature
for
an
RTO),
we
expect
that
most
PCWP
sources
will
exercise
some
caution
(
e.
g.,
reduce
the
temperature
in
a
stepwise
fashion
rather
than
making
a
significant
drop)
and
will
choose
a
temperature
level
that
gives
them
an
acceptable
"
margin
of
safety"
to
avoid
the
situation
cited
by
the
commenter.

2.7.7
Post­
deviation
performance
testing
2.7.7.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
argued
that
a
deviation
from
the
parameter
limits
set
when
a
Continuous
Parameter
Monitoring
System
(
CPMS)
is
used
may
not
indicate
violation
of
compliance.
The
commenters
noted
that
a
deviation
indicates
that
a
plant
is
outside
the
lines
of
assured
compliance,
but
the
normal
operation
of
a
process
unit
may
change
slightly
after
maintenance.
For
example,
when
the
ceramic
media
in
an
RTO
is
replaced,
there
can
be
a
noticeable
increase
in
the
air
flow
through
the
RTO,
which
could
deviate
from
the
established
parametric
range.
The
commenters
argued
that
the
rule
should
include
an
exemption
from
noncompliant
status
if
follow­
up
performance
testing
shows
that
the
compliance
options
were
being
met
during
an
"
operating
requirement"
deviation.
The
commenters
further
stated
that
the
Pulp
and
Paper
NESHAP
(
40
CFR
§
63.453(
p))
includes
a
similar
exemption,
so
the
ideas
and
wording
from
that
rule
could
be
incorporated
into
the
PCWP
NESHAP.
Specifically,
the
commenters
requested
that
the
following
paragraph
be
added
to
section
63.2240
(
What
are
the
compliance
options
and
operating
requirements
and
how
must
I
meet
them?):

(
d)
An
operating
requirement
deviation
is
not
a
violation
of
the
compliance
option
if
the
results
of
a
performance
test
using
the
procedures
in
this
paragraph
demonstrate
compliance
with
the
compliance
option
requirements
in
Table
2.
(
i)
Conduct
a
performance
test
as
specified
in
....
using
the
conditions
of
the
operating
requirement
deviation.
No
maintenance
or
changes
shall
be
made
to
the
control
system
2­
164
after
the
beginning
of
the
operating
requirement
deviation
that
would
influence
the
results
of
the
test.
(
ii)
If
the
results
of
the
performance
test
specified
in
.
.
.
(
i)
of
this
section
demonstrate
compliance
with
the
compliance
option
requirements
in
Table
2,
then
there
is
no
violation
of
the
limit.
(
iii)
If
the
results
of
the
performance
test
specified
in
.
.
.
(
i)
of
this
section
do
not
demonstrate
compliance
with
the
compliance
option
requirements
in
Table
2,
then
there
was
a
violation
of
the
limit.
Commenter
IV­
D­
27
also
recommended
that
sources
be
given
up
to
120
days
after
the
deviation
to
demonstrate
compliance;
however,
the
commenter
noted
that
the
time
frame
should
not
alleviate
the
source
from
compliance
issues
if
compliance
could
not
be
demonstrated
at
the
extended
parameter
level.

Response:
We
did
not
include
the
requested
language
in
the
final
PCWP
rule
because
we
believe
that
(
1)
the
rationale
for
including
this
provision
in
the
Pulp
and
Paper
MACT
I
rule
(
40
CFR
part
63,
subpart
S)
is
not
applicable
to
the
PCWP
rule,
and
(
2)
this
provision
is
unnecessary
given
the
changes
that
we
are
making
to
the
monitoring
provisions
in
the
final
rule.

We
note
that
the
referenced
language
in
the
Pulp
and
Paper
MACT
I
rule
regarding
"

postdeviation
performance
testing"
only
applies
to
open
biological
treatment
units
(
i.
e.,
units
used
to
biodegrade
pulp
mill
condensates)
and
not
to
other
types
of
control
systems
such
as
thermal
oxidizers,
gas
scrubbers,
and
steam
strippers.
Subpart
S
requires
pulp
and
paper
mills
that
operate
biological
treatment
units
to
conduct
quarterly
performance
tests
and
to
either
monitor
five
different
operating
parameters
or
establish
site­
specific
operating
parameters
for
the
biological
treatment
unit.
In
the
preamble
to
the
final
Pulp
and
Paper
MACT
I
rule
(
63
FR
18524,
April
15,
1998),
we
acknowledged
that
the
type
of
biological
treatment
systems
used
at
pulp
and
paper
mills
"
can
vary
widely
in
their
operation
and
performance,
depending
on
their
design,
maintenance,
and
even
their
geographical
location."
Given
this
variability,
the
number
of
parameters
that
must
be
monitored,
and
the
possibility
that
an
excursion
of
one
operating
parameter
might
not,
under
certain
circumstances,
equate
to
an
exceedance
of
the
emission
standard,
subpart
S
also
allows
sources
to
conduct
post­
deviation
performance
tests
of
the
biological
treatment
unit
to
determine
if
the
emission
standards
were
actually
exceeded
during
an
operating
parameter
excursion.
The
performance
test
must
be
performed
"
as
soon
as
practical"

after
the
beginning
of
the
monitoring
excursion.
As
discussed
in
subsequent
sections
of
this
document,
we
have
reduced
the
number
of
operating
parameters
PCWP
sources
must
monitor
for
2­
165
RTO,
RCO,
and
biofilters
to
temperature
only,
and
we
believe
that
temperature
is
both
a
controllable
parameter
and
a
reliable
indicator
of
control
device
performance.
Therefore,
we
do
not
believe
that
a
provision
for
post­
deviation
performance
testing
is
needed
in
the
final
PCWP
rule.
We
also
note
that
the
PCWP
rule
allows
sources
to
conduct
multiple
performance
tests
to
establish
the
operating
temperature
limit;
therefore,
sources
should
be
able
to
establish
a
minimum
(
or
maximum)
temperature
level
that
reflects
the
range
of
operating
conditions
expected.

2.7.8
Location
for
inlet
sampling
2.7.8.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
pointed
out
that
the
rule
is
not
clear
enough
about
the
location
for
inlet
sampling,
especially
for
coupled
control
devices.
The
commenters
recommended
that
the
rule
be
reworded
to
clearly
state
that
inlet
sampling
should
take
place
at
the
functional
inlet
of
a
control
device
sequence
or
at
the
primary
HAP
control
device
inlet.
For
example,
the
commenters
noted
that
the
final
rule
needs
to
clarify
that
sampling
should
take
place
at
the
inlet
of
a
WESP
that
precedes
an
RTO
instead
of
between
the
two
devices.
The
commenters
noted
that
many
WESP­
RTO
control
systems
are
too
closely
coupled
to
allow
for
a
sampling
location
in
between
that
meets
the
requirements
of
Method
1
or
1A,
40
CFR
60,
appendix
A.

Response:
We
agree
with
the
commenters,
and
have
revised
the
final
PCWP
rule
to
indicate
that
for
HAP­
altering
controls
in
sequence,
such
as
a
wet
control
device
followed
by
a
thermal
oxidizer,
sampling
sites
must
be
located
at
the
functional
inlet
of
the
control
sequence
(
e.
g.,
prior
to
the
wet
control
device)
and
at
the
outlet
of
the
control
sequence
(
e.
g.,
thermal
oxidizer
outlet)
and
prior
to
any
releases
to
the
atmosphere.
As
discussed
in
response
to
comment
No.
2.5.2.1,
we
also
clarified
that
facilities
demonstrating
compliance
with
the
PBCO
for
a
process
unit
with
a
wet
control
device
must
locate
sampling
sites
prior
to
the
wet
control
device.

2.7.9
Data
collection
and
handling
2.7.9.1
Comment:
Commenter
IV­
D­
03
stated
that
the
proposed
valid
data
requirements
for
CEMS
(
i.
e.,
monitoring
100
percent
of
the
hours
the
process
is
operating
except
for
monitor
malfunctions,
associated
repairs,
and
QA/
QC
activities)
are
much
more
"
subjective"
than
other
rules.
The
commenter
noted
that,
instead
of
simply
requiring
valid
data
for
greater
than
95
percent
of
the
hours
each
quarter
(
as
required
in
other
rules),
the
proposed
approach
focuses
more
on
recordkeeping
and
explaining
the
data
that
are
not
valid.
According
to
the
commenter,
2­
166
the
proposed
approach
would
require
inspectors
to
make
judgement
calls
regarding
whether
a
monitoring
malfunction
was
unavoidable
or
caused
by
poor
maintenance.
To
simplify
the
final
rule,
the
commenter
recommended
that
EPA
require
a
certain
percentage
of
data
to
be
valid
(
e.
g.,


95
percent
of
the
hours
each
quarter).

Response:
We
believe
that
the
proposed
requirement
to
conduct
monitoring
at
all
times
when
the
process
is
operating
is
appropriate.
This
requirement
is
consistent
with
other
rules
that
we
have
promulgated
recently.
We
also
believe
it
is
appropriate
that
inspectors
would
have
the
flexibility
to
determine
when
monitoring
malfunctions
are
unavoidable
or
caused
by
poor
maintenance.
Therefore,
we
did
not
modify
the
final
rule
to
include
the
95
percent
data
availability
requirement
suggested
by
the
commenter.

2.7.9.2
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
recommended
that
section
63.2268(
a)(
1)
be
revised
to
require
the
CPMS
to
simply
be
"
capable"
of
completing
a
minimum
of
one
cycle
of
operation
for
each
successive
15
minute
period.
The
commenters
also
stated
that
the
proposed
requirement
in
section
63.2268(
a)(
1)
for
15­
minute
data
collection
cycles
is
confusing
and
possibly
inconsistent
with
the
requirement
for
equally
spaced
cycles.
Section
63.2268(
a)(
1)

requires
that
the
CPMS
complete
at
least
one
cycle
in
each
successive
15­
minute
interval
and
that
a
valid
hourly
calculation
must
include
at
least
three
equally
spaced
data
points.
The
commenters
pointed
out
that
there
are
a
number
of
situations
for
which
these
guidelines
would
not
specifically
determine
the
calculation
requirements.
For
example,
the
guidelines
listed
above
could
be
interpreted
to
mean
that
the
hourly
average
must
include
three
or
more
data
points
spaced
evenly
among
themselves
but
not
spaced
equally
over
the
hour,
so
an
average
of
6
data
points
taken
at
5
minute
intervals
would
satisfy
the
rule.
After
those
six
points
were
recorded,
data
collection
might
stop
because
of
an
SSM
event,
loss
of
control
of
the
monitoring
equipment,
or
calibration
of
a
monitoring
device.
The
commenters
noted
that
the
guidelines
can
also
be
taken
together
to
mean
that
at
least
three
successive
15­
minute
intervals
are
necessary.
In
that
case,
if
the
process
starts
up
at
30
minutes
past
the
hour,
the
final
30
minutes
of
that
hour
cannot
be
considered
valid.

However,
section
63.8(
g)(
2)
of
the
General
Provisions
indicates
that
two
data
points,
each
representing
a
15­
minute
period,
should
be
averaged
in
that
case.
The
commenters
pointed
out
that
these
examples
prove
that
the
proposed
language
"
at
least
three
equally
spaced
data
values
for
that
hour"
is
ambiguous
and
should
be
revised.
The
commenters
recommended
that
EPA
require
facilities
to
average
at
least
three
data
points
taken
at
constant
intervals,
provided
that
the
2­
167
interval
is
less
than
or
equal
to
15
minutes.
The
commenters
contended
that
the
best
approach
would
be
to
ignore
the
concept
of
an
hourly
average
and
simply
calculate
the
block
average
as
the
average
of
all
evenly
spaced
measurements
in
the
block
period
with
a
maximum
measurement
interval
of
15
minutes.
The
commenters
further
noted
that
the
rule
does
not
specify
how
to
calculate
the
3­
hour
block
average
when
one
or
more
of
the
individual
hours
does
not
contain
at
least
three
valid
data
values.
The
commenters
recommended
that
the
final
rule
address
this
issue
by
stating
that
"
a
block
average
must
contain
at
least
two
valid
hourly
averages."

Response:
As
requested
by
the
commenters,
we
have
revised
the
wording
of
§
63.2269(
a)(
1)
(
formerly
§
63.2268(
a)(
1)
in
the
proposed
rule)
to
state
that
"
The
CPMS
must
be
capable
of
completing
a
minimum
of
one
cycle
of
operation
(
sampling,
analyzing,
and
recording)..."
We
added
the
parenthetical
"
sampling,
analyzing,
and
recording"
for
additional
clarity
of
the
meaning
of
a
CPMS
cycle
of
operation.

We
agree
that
the
proposed
rule
language
regarding
acceptable
data
and
data
averaging
is
somewhat
ambiguous
and
we
have
revised
the
language
accordingly.
Following
the
commenters'

recommendation,
we
have
removed
the
concept
of
an
hourly
average
from
the
rule
to
allow
block
averages
to
be
calculated
as
the
average
of
all
evenly
spaced
measurements
in
the
3­
hour
or
24­

hour
block
period
with
a
maximum
measurement
interval
of
15
minutes.
However,
removal
of
the
valid
hourly
average
consisting
of
"
at
least
three
equally
spaced
data
values
for
that
hour"
also
eliminated
any
minimum
data
availability
requirement.
Therefore,
we
added
a
minimum
data
availability
requirement
specifying
that
to
calculate
data
averages
for
each
3­
hour
or
24­
hour
averaging
period,
you
must
have
at
least
75
percent
of
the
required
recorded
readings
for
that
period
using
only
recorded
readings
that
are
based
on
valid
data.
As
discussed
in
response
to
comment
No.
2.7.9.4,
we
have
clarified
what
constitutes
valid
data
and
we
moved
the
rule
language
specifying
how
to
calculate
data
averages
to
final
§
63.2270(
d)
and
(
e).
The
minimum
data
availability
requirement
appears
in
final
§
63.2270(
f).

2.7.9.3
Comment:
Commenter
IV­
D­
27
noted
that
section
63.2270(
c)
refers
to
a
minimum
data
availability
requirement,
but
that
requirement
is
not
included
in
subpart
DDDD
or
the
General
Provisions.
The
commenter
recommended
that
the
reference
to
a
minimum
data
availability
requirement
be
removed.

Response:
A
minimum
data
availability
requirement
was
included
for
the
dry
rotary
dryer
and
veneer
redryer
work
practices
in
proposed
§
63.2268(
a)(
4).
(
Note
that
proposed
§
63.2268
2­
168
was
renumbered
§
63.2269
for
the
final
rule.)
In
addition,
we
have
extended
this
same
minimum
data
availability
requirement
for
all
CPMS
data
averages.
This
requirement
appears
in
§
63.2270(
f)
of
the
final
rule.
The
requirement
states
that
"
To
calculate
data
averages
for
each
3­

hour
or
24­
hour
averaging
period,
you
must
have
at
least
75
percent
of
the
required
recorded
readings
for
that
period
using
only
recorded
readings
that
are
based
on
valid
data..."
Because
the
final
PCWP
rule
contains
a
minimum
data
availability
requirement,
we
disagree
that
the
reference
to
a
minimum
data
availability
requirement
in
§
63.2270(
c)
should
be
removed.

2.7.9.4
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
made
several
suggestions
to
clarify
sections
63.2268
(
What
are
my
monitoring
installation,
operating,
and
maintenance
requirements?)
and
63.2270
(
How
do
I
monitor
and
collect
data
to
demonstrate
continuous
compliance?).
The
commenters
found
it
difficult
to
understand
exactly
how
to
follow
the
requirements
because
the
two
sections
use
different
words
to
discuss
the
same
subjects.
The
commenters
suggested
that
the
two
sections
be
rearranged
slightly
so
that
section
63.2268
includes
only
information
about
the
monitoring
devices
and
section
63.2270
discusses
only
the
frequency
and
methods
of
data
collection,
handling,
and
reporting.
To
accomplish
this,
the
commenters
recommended
that
sections
63.2268(
a)(
3)
and
63.2268(
a)(
4)
be
moved
to
section
63.2270.
Also,
the
commenter
pointed
out
that
section
63.2270(
c)
needs
to
be
consistent
with
section
63.2268
regarding
data
that
should
be
excluded
from
data
averages
and
calculations.

The
two
commenters
also
stated
that
proposed
sections
63.2268(
a)(
1),
63.2268(
a)(
3),
and
63.2268(
a)(
4)
need
to
be
reworded
to
more
clearly
define
which
data
should
be
included
or
excluded
from
the
block
averages.
The
commenters
noted
that
proposed
section
63.2270(
b)

states
that
all
data
taken
when
the
process
unit
is
operating
must
be
used
in
the
hourly
and
block
averages,
which
presumably
excludes
periods
when
the
process
unit
is
not
operating.
The
commenters
suggested
that
the
final
rule
would
be
clearer
and
less
confusing
if
EPA
explicitly
stated
that
any
monitoring
data
taken
during
periods
when
emission
control
equipment
are
not
accepting
emissions
from
the
production
processes
should
be
excluded
from
hourly
or
block
averages.
The
commenters
also
noted
that
section
63.2268(
a)(
3)
states
that
any
periods
in
which
SSM
occured
or
routine
maintenance
was
performed
should
not
be
included
in
the
block
average
calculation,
but
section
63.2270
does
not
include
the
same
exception.
The
commenters
stated
that,
because
SSM
events
occur
when
the
process
is
not
in
operation,
there
is
no
need
to
collect
data
from
these
periods,
and
thus,
section
63.2270
should
be
changed
to
be
consistent
with
2­
169
63.2268(
a)(
3).
The
commenters
also
noted
that
sections
63.2268(
a)(
1)
and
63.2268(
a)(
3)
seem
to
imply
that
data
collected
during
production
downtime
and
SSM
events
would
be
included
in
the
hourly
averages
but
not
in
the
block
averages.
The
commenters
also
stated
that
the
rule
was
unclear
regarding
whether
or
not
data
from
any
one­
hour
averaging
period
containing
a
15­
minute
period
of
SSM
or
a
routine
maintenance
outage
should
be
included
in
the
block
average.
In
addition,
the
commenters
stated
that
the
rule
also
was
unclear
regarding
whether
or
not
a
block
average
would
be
calculated
if
the
period
contained
a
15­
minute
period
of
SSM
or
maintenance
downtime.
To
clear
up
the
confusion,
the
commenters
suggested
that
EPA
should
modify
sections
63.2268(
1)
and
(
3)
to
exclude
periods
that
include
SSM
events
from
the
hourly
averages
that
are
used
to
compute
the
block
averages.
The
commenters
requested
that
the
wording
in
section
63.2268(
a)(
4)
also
be
revised
to
include
this
clarification.

Response:
We
agree
with
the
commenters
that
there
was
some
ambiguity
in
the
structure
of
proposed
§
63.2268
and
§
63.2270
that
could
cause
confusion.
To
remedy
this,
we
rearranged
the
two
sections
as
the
commenters
suggested.
We
moved
proposed
§
§
63.2268(
a)(
3)
and
(
4)
to
final
§
63.2270
(
now
§
63.2270(
d)
and
(
e)).
Rather
than
repeating
which
data
should
be
excluded
from
data
averages
in
§
63.2270(
d)
and
(
e),
these
new
sections
now
refer
to
§
63.2270(
b)
and
(
c)

when
discussing
data
that
should
not
be
included
in
data
averages.
We
also
added
data
recorded
during
periods
of
SSM
to
the
list
of
data
that
should
be
excluded
from
data
averages
in
§
63.2270.

We
believe
these
changes
to
the
structure
and
wording
of
the
rule
should
fully
address
the
commenters'
concerns.

2.7.9.5
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
noted
that
the
proposed
PCWP
rule
does
not
provide
any
alternatives
to
the
definition
of
a
one­
hour
period
found
in
the
General
Provisions
(
40
CFR
63.2).
The
commenters
requested
that
facilities
be
given
the
option
of
beginning
a
one­
hour
period
at
a
time
that
is
convenient
depending
on
shift
changes,
employee
duties
at
the
end
of
a
shift,
and
settings
on
the
systems
that
record
data.

Response:
A
one­
hour
period
is
defined
in
the
General
Provisions
as
follows:

One­
hour
period,
unless
otherwise
defined
in
an
applicable
subpart,
means
any
60­
minute
period
commencing
on
the
hour.

The
final
PCWP
NESHAP
exercises
the
flexibility
of
this
definition
and
provides
a
different
definition
of
one­
hour
period
for
PCWP
facilities
as
follows:

One­
hour
period
means
a
60­
minute
period.
2­
170
We
removed
the
phrase
"
commencing
on
the
hour"
from
the
definition
because
when
the
hour
commences
is
not
as
important
as
whether
or
not
the
timeframe
for
the
block
average
is
clearly
defined
and
consistently
applied.

2.7.9.6
Comment:
Commenter
IV­
D­
27
stated
that
section
63.2268(
a)(
3)
should
include
language
that
follows
section
63.8(
g)(
4)
of
the
General
Provisions
on
rounding
of
data.
The
commenter
stated
that
hourly
and
block
average
data
should
be
rounded
to
the
number
of
significant
digits
of
the
relevant
standard.
According
to
the
commenter,
for
parameters
such
as
temperature,
the
number
of
significant
digits
would
be
the
same
as
the
measurement
device
tolerance
or
minor
division
on
the
appropriate
chart
recorder
specified
in
section
63.2268.

Response:
Table
10
to
subpart
DDDD
(
Applicability
of
General
Provisions
to
subpart
DDDD)
indicates
that
§
63.8(
g),
including
§
63.8(
g)(
4),
applies
to
the
PCWP
NESHAP.

(
Note
that
proposed
§
63.2268
was
renumbered
§
63.2269
for
the
final
rule.)

2.7.10
Selection
of
operating
parameter
limits
 
general
2.7.10.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
objected
to
EPA's
approach
to
selecting
operating
parameter
limits
because
the
approach
does
not
distinguish
between
"
naturally
variable"
parameters
and
controllable
parameters,
and
because
many
of
the
selected
parameters
do
not
directly
correlate
to
control
device
performance.
The
commenters
argued
that
there
is
a
difference
between
controllable
parameters
(
e.
g.,
RTO
temperature,
scrubber
liquid
flow
rate,
and
other
parameters
that
are
directly
manipulated
by
the
operator
or
facility)
and
"
naturally
variable"

parameters
(
e.
g.,
biofilter
inlet
temperature,
moisture
content
of
dryer
exhaust,
and
uncontrolled
THC
emissions
concentration),
and
the
rule
does
not
provide
sufficient
guidance
for
the
variable
parameters.
The
commenters
stated
that
the
normal
operating
range
for
controllable
parameters
can
easily
be
set
when
the
tests
for
initial
compliance
are
run;
however,
"
naturally
variable"

parameters
are
influenced
by
the
process
performance,
weather,
raw
materials,
and
similar
factors,

and
thus,
they
are
difficult
for
an
operator
to
manipulate.
The
commenters
noted
that
the
operating
range
for
"
naturally
variable"
parameters
cannot
be
set
as
easily
because
the
conditions
during
the
initial
compliance
demonstration
may
or
may
not
be
average
or
normal.
The
commenters
contended
that,
instead
of
using
the
initial
compliance
tests
to
establish
limits
for
naturally
variable
parameters,
the
limits
should
be
based
on
emission
control
design
principles.

The
commenters
stated
that
examples
of
control
equipment
design­
based
operating
parameters
would
be
RTO
residence
time,
outlet
THC
concentration,
and
biofilter
bed
temperature.
2­
171
The
commenters
also
stated
that
EPA
has
made
overly
broad
assumptions
about
relationships
between
operating
parameters
and
emission
control
equipment
performance
and
requested
that
those
relationships
be
re­
examined.
The
commenters
stated
that
the
parameters
for
monitoring
compliance
should
be
specific
to
the
process
or
control
unit
and
based
on
design
and
scientific
principles.
The
commenters
noted,
however,
that
the
proposed
rule
contains
requirements
for
operating
parameters
that
may
not
exactly
relate
to
the
performance
of
that
unit,

such
as
measuring
the
static
pressure
of
a
thermal
oxidizer.
The
commenters'
specific
objections
and
recommendations
regarding
the
selection
of
parameters
to
be
monitored
for
specific
processes
and
control
devices
are
discussed
in
sections
2.7.11
through
2.7.15.

Response:
We
agree
with
commenters
that
there
are
naturally
variable
parameters
and
controllable
parameters.
We
have
reduced
the
parameters
to
be
continuously
monitored
and
controlled
for
all
control
devices
to
temperature
only.
Responses
to
comments
regarding
specific
parameters
are
discussed
in
the
sections
below.

2.7.11
Selection
of
RTO
and
RCO
monitoring
parameters
2.7.11.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
recommended
changes
to
the
proposed
requirements
to
monitor
the
operating
temperature
of
thermal
and
catalytic
oxidizers
in
§
§
63.2262
(
k)(
1)
and
(
l)(
1).
The
commenters
stated
that
the
method
of
determining
a
minimum
combustion
temperature
is
inappropriate.
Because
of
the
variation
in
combustion
temperatures
during
normal
conditions
and
the
statistics
involved
in
averaging,
a
facility
will
have
to
perform
the
initial
test
at
lower
than
normal
temperature
conditions
to
ensure
that
the
minimum
combustion
temperature
will
be
maintained
a
majority
of
the
time.
The
commenter
argued
that
based
on
a
Monte
Carlo
simulation,
if
the
minimum
temperature
is
set
as
the
proposed
rule
requires,
there
is
about
a
30
percent
chance
that
a
facility
will
violate
the
limit
once
in
a
six
month
period
and
about
a
10
percent
chance
that
a
facility
will
violate
the
limit
more
than
ten
times
in
six
months,
regardless
of
standard
deviation.
In
addition,
the
commenter
stated
that
a
study
by
NCASI
showed
that
increases
and
decreases
in
RTO
operating
temperature
within
the
normal
operating
ranges
had
no
effect
on
the
destruction
of
HAP.
Therefore,
the
commenters
recommended
that
the
final
rule
allow
facilities
to
conduct
the
initial
compliance
test
for
RTOs
at
the
design
specifications
of
the
control
device,
and
then
allow
facilities
to
operate
the
thermal
oxidizers
up
to
50
°
F
lower
than
the
average
obtained
by
the
test.
2­
172
The
commenters
also
noted
that,
for
RCOs,
when
the
THC
concentration
in
the
inlet
is
high,
the
RCO
will
not
need
any
additional
heat
and
can
operate
at
temperatures
higher
than
the
set
point.
Therefore,
if
the
initial
compliance
tests
are
conducted
under
these
conditions,
the
operating
temperature
limit
will
be
too
high
for
production
rates
at
less
than
full
capacity.
The
commenters
recommended
that,
rather
than
base
the
minimum
catalyst
temperature
on
"
artificial
conditions"
designed
to
keep
the
THC
concentration
low
enough
during
the
compliance
test
to
drop
the
RCO
temperature
to
a
minimum
set
point,
operators
should
be
allowed
to
set
the
operating
limit
at
a
level
that
is
100
°
F
above
the
minimum
operating
temperature
of
the
catalyst.

The
commenters
stated
that
these
changes
to
the
final
rule
for
thermal
and
catalytic
oxidizers
would
eliminate
the
practice
of
operating
control
devices
below
expected
normal
operating
temperatures
during
the
compliance
test
in
order
to
provide
a
compliance
margin.
The
commenters
also
noted
that
another
option
would
be
to
perform
tests
at
the
boundaries
rather
than
"
representative"
operating
conditions,
as
discussed
previously
(
see
Section
2.7.5).

Response:
We
disagree
with
the
commenters'
request
to
include
a
50

F
margin
around
the
minimum
operating
temperature
established
during
the
compliance
test.
In
general,
selection
of
the
representative
operating
conditions
for
both
the
process
and
the
control
device
for
conducting
the
performance
test
is
an
important,
and
sometimes
complex,
task.
Establishing
the
add­
on
control
device
operating
limit
at
the
level
demonstrated
during
the
performance
test
is
appropriate.
The
PCWP
rule
allows
a
facility
to
select
operating
limits
based
on
site­
specific
operating
conditions
and
the
facility
is
able
to
consider
the
need
for
temperature
fluctuations
in
this
selection.
The
PCWP
rule
requires
that
the
operating
limit
be
based
on
the
average
of
the
three
minimum
temperatures
measured
during
a
3­
hour
performance
test
(
rather
than
on
the
average
temperature
over
the
3­
hour
period,
for
example)
to
accommodate
normal
variation
during
operation
and
ensure
that
the
minimum
temperature
established
represents
the
lowest
of
the
temperatures
measured
during
the
compliant
test.
The
facility
does
have
the
option
of
operating
the
oxidizer
at
a
lower
setpoint
during
the
performance
test
in
order
to
provide
a
margin
of
safety
during
normal
operation.
These
provisions
allow
sufficient
flexibility,
and
an
additional
tolerance
for
a
50
°
F
(
28
°
C)
temperature
variation
is
not
necessary.
Therefore,
the
final
rule
does
not
allow
facilities
to
operate
thermal
oxidizers
50
°
F
lower
than
the
average
temperature
during
testing.
2­
173
Regarding
the
study
conducted
by
NCASI,
we
note
that
the
temperature
range
of
RTOs
tested
as
part
of
that
study
ranged
from
a
low
of
1430

F
to
a
high
of
1675

F
(
no
RCOs
were
tested).
We
agree
that
the
study
results
show
that,
within
that
temperature
range,
there
was
no
noticeable
correlation
between
HAP
destruction
efficiency
and
temperature;
however,
the
study
did
show
that
acceptable
HAP
destructions
were
achieved
within
that
range
for
the
five
RTOs
that
were
tested.
The
temperature
range
used
during
the
study
correlates
with
actual
RTO
operating
temperatures
reported
by
PCWP
facilities
(
i.
e.,
1425

F
to
1625

F),
and
therefore,

acceptable
destruction
efficiencies
would
be
expected
to
occur
within
the
stated
temperature
range.
10
No
testing
was
conducted
at
temperatures
lower
than
the
"
minimum
normal
operating
level,"
for
the
individual
units
and
therefore,
we
cannot
be
assured
that
RTOs
operating
at
50

F
below
1430

F
(
i.
e.,
1380

F)
will
achieve
the
desired
destruction
efficiency.
In
addition,
the
final
rule
allows
PCWP
facilities
to
conduct
multiple
performance
tests
to
set
the
minimum
operating
temperature
for
RCOs
and
RTOs,
and
therefore,
PCWP
sources
would
have
the
option
to
conduct
their
own
studies
(
under
a
variety
of
representative
operating
conditions)
in
order
to
establish
the
minimum
operating
temperature
at
a
level
that
they
could
maintain
and
that
would
provide
them
with
an
acceptable
"
compliance
margin."

With
regard
to
RCOs,
we
agree
with
the
commenters
that
when
the
THC
concentration
in
the
inlet
is
high,
the
RCO
will
not
need
any
additional
heat
and
it
can
operate
at
temperatures
higher
than
the
set
point.
Therefore,
if
the
initial
compliance
tests
are
conducted
under
these
conditions,
the
operating
temperature
limit
will
be
too
high
for
production
rates
at
less
than
full
capacity.
However,
the
final
rule
requires
emissions
testing
under
representative
operating
conditions
and
not
maximum
operating
conditions.
In
addition,
we
do
not
agree
with
the
commenter's
solution
to
set
the
operating
limit
at
100
°
F
above
the
minimum
operating
[
design]

temperature
of
the
catalyst.
As
with
RTOs,
we
believe
it
is
incumbent
upon
the
facility
to
demonstrate
performance
and
establish
the
operating
limits
during
the
compliance
demonstration
test.
Therefore,
the
rule
has
not
been
changed,
and
it
requires
the
facility
to
establish
the
minimum
catalytic
oxidizer
operating
temperature
during
the
compliance
test.
As
noted
below,

we
have
provided
more
flexibility
to
the
facility
regarding
temperature
monitoring
for
an
RCO.

We
recognize
that
in
a
typical
RTO
and
RCO,
the
combustion
chamber
contains
multiple
burners,
and
that
each
of
these
burners
may
have
multiple
thermocouples
for
measuring
the
temperature
associated
with
that
burner.
The
final
rule
requires
establishing
and
monitoring
a
2­
174
minimum
firebox
temperature
for
RTOs.
In
an
RTO,
the
minimum
firebox
temperature
is
actually
represented
by
multiple
temperature
measurements
for
multiple
burners
within
the
combustion
chamber.
Thus,
the
final
rule
clarifies
that
facilities
operating
RTOs
may
monitor
the
temperature
in
multiple
locations
within
the
combustion
chamber
and
calculate
the
average
of
the
temperature
measurements
to
use
in
establishing
the
minimum
firebox
temperature
operating
limit.

Finally,
the
final
rule
includes
an
option
(
in
lieu
of
monitoring
oxidizer
temperature)
for
monitoring
and
maintaining
the
oxidizer
outlet
THC
concentration
at
or
below
the
operating
limit
established
during
the
performance
test.
Use
of
the
THC
monitoring
option
eliminates
the
concerns
regarding
establishing
and
monitoring
oxidizer
operating
temperatures
(
i.
e.,
it
provides
facilities
complete
flexibility
in
operation
of
the
control
device,
as
long
as
the
THC
outlet
concentration
remains
below
the
operating
limit).

2.7.11.2
Comment:
Commenters
IV­
D­
21,
IV­
D­
23,
and
IV­
D­
27
stated
that,
for
RCOs,

instead
of
placing
the
thermocouple
in
a
location
to
measure
the
gas
stream
before
it
reaches
the
catalyst
bed,
the
thermocouple
should
be
placed
in
a
location
to
measure
the
temperature
of
the
gas
in
the
combustion
chamber
between
the
catalyst
beds.
Commenters
IV­
D­
21
and
IV­
D­
27
noted
that,
because
the
gas
flow
reverses
direction
in
RCOs,
the
temperature
monitor
will
not
consistently
measure
the
gas
at
the
same
point
in
the
process,
such
that
sometimes
the
gas
temperature
will
be
recorded
after
the
catalyst
beds
instead
of
before.
Also,
the
proposed
PCWP
rule
does
not
provide
a
location
for
the
temperature
monitor
if
there
are
more
than
two
catalyst
beds.
Commenter
IV­
D­
23
also
noted
that
plugging
near
the
temperature
probe
in
the
bed
can
cause
inaccurate
readings.
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
placing
the
monitor
inside
the
combustion
chamber
eliminates
the
need
for
multiple
monitors
and
avoids
problems
such
as
overheating
and
burnout
of
the
catalyst
media
caused
by
the
temperature
delay
between
the
burner
and
the
RCO
inlet.

Response:
Most
RCOs
have
two
or
more
catalyst
sections
with
a
"
combustion
chamber"

located
in
between
and
supplemental
gas
heating.
The
purpose
of
the
supplemental
gas
heating
is
to
provide
the
necessary
heat
input
during
startup,
as
well
as
to
ensure
that
the
minimum
temperature
necessary
to
initiate
the
combustion
reaction
on
the
catalyst
is
maintained
during
operation
(
i.
e.,
that
a
minimum
catalyst
inlet
temperature
is
maintained).
The
operation
of
these
units
and
the
associated
temperature
measurement
and
monitoring
is
complex.
The
commenters
properly
indicated
that
because
the
gas
flow
reverses
direction
in
RCOs,
the
temperature
monitor
2­
175
will
not
consistently
measure
the
gas
at
the
same
point
in
the
process,
such
that
sometimes
the
gas
temperature
will
be
recorded
after
the
catalyst
beds
instead
of
before
(
i.
e.,
at
the
inlet).
We
did
not
intend
to
require
the
separate
measurement
of
each
"
inlet"
temperature
by
switching
the
data
recording
back
and
forth
to
coincide
with
the
flow
direction
into
the
bed.
The
intention
is
to
monitor
the
"
minimum"
temperature
of
the
gas
entering
the
catalyst
to
ensure
that
the
minimum
temperature
is
maintained
at
the
operating
level
during
which
compliance
was
demonstrated.
This
can
be
accomplished
by
measuring
the
temperature
in
the
regenerative
canisters
at
one
or
more
locations.
Measuring
the
inlet
temperatures
of
each
catalyst
bed
and
then
determining
the
average
temperature
for
all
catalyst
beds
is
one
approach;
even
though
some
of
the
beds
are
cooling
and
others
are
heating,
the
average
across
all
of
the
catalyst
beds
should
not
vary
significantly.

Another
acceptable
alternative
is
monitoring
the
"
combustion
chamber"
temperature
as
suggested
by
the
commenters.
The
monitoring
location(
s)
selected
by
the
facility
may
depend
on
the
operating
conditions
(
i.
e.,
THC
loading
to
the
unit)
during
the
performance
test
and
on
how
the
unit
is
expected
to
be
operated
in
the
future.
The
objective
is
to
establish
monitoring
and
operating
limits
that
are
representative
of
the
conditions
during
the
compliance
demonstration
test(
s)
and
representative
of
the
temperature
to
which
the
catalyst
is
exposed.
We
recognize
the
need
for
flexibility
in
selecting
the
temperature(
s)
to
be
monitored
as
operating
limits
for
RCOs.

Therefore,
the
final
rule
provides
flexibility
by
allowing
facilities
with
RCOs
to
choose
between
basing
their
minimum
RCO
temperature
limit
on
the
average
of
the
inlet
temperatures
for
all
catalyst
beds
or
the
average
temperature
within
the
combustion
chamber.
If
there
are
multiple
thermocouples
at
the
inlet
to
each
catalyst
bed,
then
we
would
expect
facilities
to
average
the
measurements
from
each
thermocouple
to
provide
a
representative
catalyst
bed
inlet
temperature
for
each
individual
catalyst
bed.
The
same
would
apply
for
facilities
establishing
a
minimum
catalytic
oxidizer
temperature
based
on
multiple
burner
temperatures
within
the
combustion
chamber.

2.7.11.3
Comment:
Commenters
IV­
D­
03,
IV­
D­
21,
and
IV­
D­
27
stated
that
PCWP
facilities
should
not
be
required
to
measure
and
comply
with
limits
on
the
static
pressure
at
the
inlet
to
a
thermal
oxidizer.
According
to
the
preamble
(
68
FR
1292),
monitoring
the
static
pressure
at
the
inlet
to
a
thermal
oxidizer
is
supposed
to
indicate
the
exhaust
flow
rate
entering
the
thermal
oxidizer
and
the
capture
efficiency.
However,
the
PCWP
rule
also
states
that
facilities
must
maintain
either
the
static
pressure
or
the
maximum
process
unit
exhaust
flow
rate,
making
2­
176
EPA's
real
wishes
unclear.
The
inlet
static
pressure
to
a
thermal
oxidizer
is
not
a
reliable
indicator
of
the
flow
through
the
oxidizer,
the
destruction
efficiency,
or
the
capture
efficiency.

The
commenters
also
noted
that
the
preamble
to
the
PCWP
rule
says
that
monitoring
the
static
pressure
can
indicate
to
the
operator
when
there
is
a
problem
such
as
plugging.
However,
static
pressure
is
usually
the
last
indicator
of
these
types
of
control
device
problems.
The
commenters
agreed
that
measuring
those
parameters
helps
to
assess
the
overall
condition
of
the
oxidizer,
but
EPA
should
not
set
limits
on
them.
Instead,
all
of
the
measured
parameters
should
be
examined
together
to
determine
if
there
is
a
problem
with
the
control
device,
and
operators
should
follow
the
work
practices
to
help
ensure
compliance.
The
operators
should
also
keep
track
of
a
combination
of
parameters
to
tell
them
when
maintenance
should
be
performed
to
avoid
those
problems.
Monitoring
the
static
pressure
actually
helps
to
control
the
speed
of
the
fan
or
the
oxidizer
dampers
so
that
all
the
air
flows
are
balanced.
Static
pressure
is
adjusted
to
avoid
vacuum
conditions
in
the
ductwork
of
multiple­
dryer
systems
treated
by
one
control
device
when
one
dryer
is
shut
down,
to
improve
emission
collection
efficiency
and
prevent
fugitive
emissions,

and
to
adjust
the
pressure
drop
across
a
bag
filter
as
it
fills
with
particulates,
among
others.

However,
if
operators
are
required
to
keep
the
static
pressure
within
an
operating
range,
it
will
limit
their
ability
to
maintain
capture
efficiency.
Also,
the
normal
static
pressure
at
the
oxidizer
inlet
may
change
over
time
as
particulate
matter
accumulates
in
the
heat
exchanger.
If
EPA
requires
facilities
to
maintain
the
static
pressure
at
a
set
level,
the
oxidizer
would
need
to
be
cleaned
more
often,
meaning
that
facilities
would
need
more
downtime.
The
commenter
requested
that
the
EPA
recognize
static
pressure
as
one
of
a
number
of
parameters
that
can
ensure
that
the
flow
rate
is
sufficient
instead
of
requiring
facilities
to
measure
it.
The
EPA
should
keep
in
mind
that
maintaining
a
certain
static
pressure
does
not
necessarily
ensure
that
a
dryer
is
in
compliance,
and
likewise,
a
deviation
from
the
static
pressure
endpoint
does
not
necessarily
indicate
that
the
dryer
is
out
of
compliance
because
there
was
likely
no
change
in
the
capture
or
destruction
rate.
If
static
pressure
monitoring
becomes
mandatory,
then
large
operational,

maintenance,
and
reporting
burdens
will
be
placed
on
facility
personnel.
Facilities
should
be
able
to
demonstrate
that
an
appropriate
air
flow
is
being
maintained
by
a
combination
of
parameters
that
include
monitoring
static
pressure,
flow,
and
fan
performance
and
documenting
that
the
system
was
designed
well.
Also,
if
retained
as
an
operating
parameter,
the
minimum
limit
on
the
2­
177
static
pressure
should
be
removed,
and
the
averaging
period
should
be
increased
to
24
hours
to
avoid
deviations
caused
by
statistics.

Response:
For
the
reasons
stated
by
the
commenters,
we
agree
that
the
requirement
to
monitor
and
establish
operating
limits
for
static
pressure
(
as
an
alternative
to
air
flow)
should
be
dropped
from
the
monitoring
requirements
for
thermal
and
catalytic
oxidizers.
We
deleted
this
requirement
from
the
final
rule.

2.7.11.4
Comment:
Commenters
IV­
D­
03,
IV­
D­
21,
and
IV­
D­
27
stated
that
the
monitoring
and
control
requirements
on
air
flow
through
control
devices
are
unnecessary.
The
commenters
noted
that
the
preamble
to
the
PCWP
rule
states
that
monitoring
air
flow
would
provide
an
indicator
of
capture
efficiency;
however
the
commenters
contended
that
air
flow,
like
static
pressure,
is
an
unreliable
method
of
monitoring
capture
efficiency.
Theoretically,
the
best
performance
is
achieved
when
the
temperature
is
above
a
minimum
and
flow
is
below
a
maximum.

However,
applying
a
compliance
limit
to
the
maximum
of
the
flow
rate
through
a
thermal
oxidizer
limits
the
possible
capture
efficiency.
Establishing
a
minimum
flow
rate
for
the
oxidizer
could
make
sense,
since
any
air
not
flowing
through
the
oxidizer
would
go
untreated.
However,
if
such
a
limit
is
set,
EPA
should
keep
in
mind
that
numerous
factors
affect
the
air
flow
through
the
control
device,
including
the
rate
of
water
removal
in
dryers,
leakage
of
tramp
air
into
the
process,
the
number
of
processes
operating
for
control
units
that
receive
emissions
from
multiple
production
units,
the
controls
placed
on
veneer
dryers
to
avoid
pulling
too
much
cold
air
into
the
dryer,
the
retention
time
for
rotary
dryers,
and
the
overall
production
speed
due
to
process
adjustments.
If
the
air
flow
to
the
control
device
is
not
constant,
then
monitoring
the
air
flow
through
the
control
device
will
not
be
an
accurate
measure
of
capture
efficiency.
Also,
if
EPA
wants
to
require
facilities
to
monitor
air
flow
to
demonstrate
that
press
enclosures
meet
Method
204
standards,
that
condition
should
be
part
of
the
enclosure
requirements,
not
those
of
the
control
device.
Any
limit
to
the
air
flow
that
would
cause
a
minimum
production
rate
should
not
be
considered.
Most
systems
are
fixed­
flow,
so
the
design
of
the
system
will
define
the
flow.
For
oxidizers,
EPA
should
not
place
a
minimum
on
the
air
flow,
and
monitoring
the
air
flow
should
be
just
one
option
for
demonstrating
capture
efficiency.

Response:
For
the
reasons
stated
by
the
commenters,
we
agree
that
the
requirement
to
monitor
and
establish
operating
limits
for
air
flow
(
as
an
alternative
to
static
pressure)
should
be
2­
178
dropped
from
the
monitoring
requirements
for
thermal
and
catalytic
oxidizers.
We
deleted
this
requirement
from
the
final
rule.

2.7.11.5
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
one
operating
limit
should
be
sufficient
for
each
control
device,
but
acknowledged
EPA's
historical
preference
for
two
operating
limits
per
control
device.
The
commenters
noted
that
if
EPA
decided
to
delete
the
operating
limits
for
static
pressure
and
air
flow,
thus
leaving
only
one
operating
limit
(
temperature)
for
thermal
and
catalytic
oxidizers,
EPA
could
add
a
requirement
to
demonstrate
appropriate
oxidizer
residence
time
during
the
initial
performance
test.
According
to
the
commenters,
the
demonstration
test
could
involve
demonstrating
the
required
destruction
efficiency
while
operating
the
oxidizer
within
10
percent
of
maximum
fan
capacity.
As
long
as
the
oxidizer
cannot
exceed
the
maximum
design
flow
rate,
then
no
further
flow
rate
monitoring
should
be
required.
However,
if
there
is
a
possibility
that
the
actual
residence
time
of
oxidizer
could
be
shorter
than
designed
(
e.
g.,
for
those
oxidizers
with
fan
capacities
that
exceed
the
design
oxidizer
residence
time),
the
facility
should
monitor
either
the
flow
rate
or
another
parameter
during
operation
to
demonstrate
that
the
residence
time
remains
within
the
designed
time.

Commenter
IV­
D­
27
gave
an
example
whereby
a
facility
installs
a
larger
RTO
or
RCO
than
necessary
to
allow
for
future
expansion,
such
that
the
fan
would
not
be
running
at
full
capacity.

In
such
cases,
the
commenter
stated
that
the
facility
could
petition
EPA
to
conduct
the
compliance
tests
at
the
anticipated
operating
conditions
and
limit
either
the
fan
speed
or
the
air
flow
rate.
In
that
case,
air
flow
monitoring
would
be
appropriate,
but
it
should
not
be
mandatory
for
everyone.

Response:
As
stated
in
the
previous
response,
we
have
deleted
air
flow
(
and
static
pressure)
monitoring
from
the
operating
requirements
for
thermal
and
catalytic
oxidizers
in
the
final
PCWP
rule.
The
final
rule
requires
continuous
monitoring
of
temperature
for
thermal
oxidizers.
We
believe
that
temperature
is
both
a
controllable
parameter
and
a
reliable
indicator
of
control
efficiency
for
thermal
oxidizers,
and
that
it
is
appropriate
to
require
monitoring
of
a
single
parameter
(
temperature)
for
this
device.
For
catalytic
oxidizers,
the
final
rule
requires
continuous
monitoring
of
temperature
and
an
annual
test
of
catalyst
activity
level
(
see
response
to
comment
No.
2.7.11.6
below).
We
believe
that
these
two
requirements
together
will
provide
sufficient
monitoring
of
the
catalytic
oxidizers.
Therefore,
the
final
rule
does
not
include
the
initial
residence
time
test
suggested
by
the
commenters.
2­
179
2.7.11.6
Comment:
Commenter
IV­
D­
07
suggested
that
a
catalyst
sampling
and
testing
method
be
incorporated
into
the
rule.
The
current
requirement
to
monitor
inlet
pressure
may
not
be
sufficient
to
detect
catalyst
problems
such
as
poisoning,
blinding,
or
degradation.

Response:
We
agree
with
the
commenter
that
a
catalyst
activity
level
check
is
needed
because
catalyst
beds
can
become
poisoned
and
rendered
ineffective.
An
activity
level
check
can
consist
of
passing
an
organic
compound
of
known
concentration
through
a
sample
of
the
catalyst,

measuring
the
percentage
reduction
of
the
compound
across
the
catalyst
sample,
and
comparing
that
percentage
reduction
to
the
percentage
reduction
for
a
fresh
sample
of
the
same
type
of
catalyst.
One
company
that
performs
this
service
charges
less
than
$
800;
and
in
this
case,
the
catalyst
sample
is
removed
from
the
bed
by
the
facility
and
then
shipped
to
the
testing
company
where
its
ability
to
oxidize
organic
compounds
is
determined
with
a
flame
ionization
detector.
26
In
response
to
this
comment,
we
added
to
the
final
rule
a
requirement
for
facilities
with
catalytic
oxidizers
to
perform
an
annual
catalyst
activity
check
on
a
representative
sample
of
the
catalyst
and
to
take
any
necessary
corrective
action
to
ensure
that
the
catalyst
is
performing
within
its
design
range.
Corrective
actions
may
include
washing
or
baking
out
the
catalytic
media,

conducting
an
emissions
test
to
ensure
the
catalytic
media
is
resulting
in
the
desired
emissions
reductions,
or
replacing
all
or
part
of
the
media.
Catalysts
are
designed
to
have
an
activity
range
over
which
they
will
reduce
emissions
to
the
desired
levels,
and
therefore,
the
final
rule
specifies
that
corrective
action
is
needed
only
when
the
catalyst
activity
is
outside
of
this
range.
It
is
not
our
intention
for
facilities
to
replace
catalyst
if
the
catalytic
media
is
not
performing
at
the
maximum
level
it
achieved
when
the
catalyst
was
new.
The
final
rule
specifies
that
the
catalyst
activity
check
must
be
done
on
"
a
representative
sample
of
the
catalyst"
to
ensure
that
facilities
that
may
have
recently
conducted
a
partial
media
replacement
do
not
sample
only
the
fresh
catalytic
media
from
the
catalytic
oxidizer
for
the
catalyst
activity
check.

2.7.12
Process
incineration
monitoring
requirements
2.7.12.1
Comment:
Commenter
IV­
D­
27
noted
that
combustion
units
with
heat
input
capacity
greater
than
or
equal
to
44
megawatts
(
MW)
that
accept
process
exhausts
into
the
flame
zone
would
be
exempt
from
the
initial
performance
testing
and
operating
requirements
for
thermal
oxidizers
as
stated
in
the
proposed
rule.
The
commenter
requested
that
EPA
modify
the
language
in
the
final
PCWP
rule
to
conform
with
similar
language
in
the
HON
and
the
Pulp
and
Paper
Cluster
rule
as
follows
(
modified
text
in
italics):
"
Combustion
units
with
heat
input
capacity
2­
180
greater
than
or
equal
to
44
megawatts
that
accept
process
exhausts
into
the
flame
zone
or
with
the
combustion
air
are
exempt
from
the
initial
performance
testing
and
operating
requirements
for
thermal
oxidizers."
The
commenter
gave
an
example
whereby
the
process
exhaust
from
a
veneer
dryer
might
be
added
as
combustion
air
for
a
process
boiler
(
e.
g.,
as
under­
fire
air,
over­
fire
air,

or
both)
instead
of
being
added
directly
to
the
flame
zone
of
the
boiler.
The
commenter
noted
that
in
the
HON
and
Cluster
rules,
EPA
recognized
that
boilers
greater
than
44
MW
typically
had
greater
than
3/
4­
second
residence
time,
ran
hotter
than
1500

F,
and
usually
had
destruction
efficiencies
greater
than
98
percent.
(
See
65
FR
3909,
January
25,
2000
and
65
FR
80762,

December
22,
2000
at
§
63.443(
d)(
4)(
ii)).
The
commenter
stated
that
the
design
and
construction
of
PCWP
boilers
follow
the
same
principles
that
would
allow
for
these
operating
conditions.

Response:
As
noted
by
the
commenter,
the
HON
(
subpart
G)
and
the
final
Pulp
and
Paper
MACT
I
rule
(
subpart
S)
included
the
requested
provision
for
boilers
(
and
for
recovery
furnaces
at
pulp
and
paper
mills)
with
heat
input
capacity
greater
than
44
MW,
because
performance
data
showed
that
these
large
boilers
achieve
at
least
98
percent
combustion
of
HAP
when
the
emission
streams
are
introduced
with
the
primary
fuel,
into
the
flame
zone,
or
with
the
combustion
air.

Lime
kilns
at
pulp
and
paper
mills
were
excluded
from
this
provision
because
we
did
not
have
any
data
to
show
that
lime
kilns
can
achieve
the
required
destruction
efficiency
when
the
HAP
emission
stream
is
introduced
with
the
combustion
air.
Therefore,
lime
kilns
at
pulp
and
paper
mills
that
accept
HAP
emission
streams
must
introduce
the
stream
into
the
flame
zone
or
with
the
primary
fuel.
We
do
not
have
the
data
to
show
that
the
design
and
construction
of
large
(>
44
MW)
combustion
units
at
PCWP
plants
would
be
similar
to
boilers
found
at
pulp
and
paper
mills.

Furthermore,
combustion
units
at
PCWP
plants
with
heat
input
capacity
of
greater
than
44
MW
are
less
prevalent
than
smaller
(
i.
e.,
less
than
44
MW)
PCWP
combustion
units,
and
many
of
these
smaller
combustion
units
are
not
boilers.
As
discussed
in
the
response
to
comment
No.
2.7.12.2,

we
are
eliminating
the
testing
and
monitoring
requirements
for
these
smaller
combustion
units,

provided
that
the
HAP
emission
stream
is
introduced
into
the
flame
zone.
For
these
reasons,
the
final
PCWP
rule
does
not
extend
the
exemption
from
testing
and
monitoring
to
those
boilers
greater
than
44
MW
that
introduce
the
HAP
emission
stream
with
the
combustion
air,
as
requested
by
the
commenter.
2­
181
2.7.12.2
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
noted
that
combustion
units
with
a
heat
capacity
input
of
greater
than
or
equal
to
44
MW
(
150
million
BTU/
hr)
are
exempt
from
initial
performance
testing
and
operating
requirements,
and
the
commenter
requested
that
combustion
units
with
a
heat
capacity
input
of
less
than
44
MW
that
use
process
exhausts
in
the
flame
zone
be
exempt
as
well.
The
exemption
would
be
based
on
the
demonstration
that
the
combustion
unit's
temperature
and
residence
time
are
sufficient
to
destroy
the
necessary
HAP.

For
example,
some
plants
install
a
combustion
unit
between
the
press
and
the
dryer
so
that
the
emissions
from
the
press
can
provide
heat
for
the
dryer.
These
units
can
also
burn
the
emissions
from
small
process
units,
such
as
blenders,
without
requiring
supplemental
fuel.
For
most
of
these
setups,
it
would
be
difficult
to
conduct
a
compliance
test
because
many
of
the
combustion
units
do
not
have
a
real
vent
to
serve
as
a
sampling
location,
and
the
dryer
emissions
do
not
have
the
same
composition
as
the
gas
traveling
from
the
combustion
output
to
the
dryer
input.
Since
most
wood
products
dryers
have
a
heat
capacity
of
20
to
50
million
Btu/
hr,
they
would
not
meet
the
exemption
discussed
above.
If
P2
measures
are
being
applied
to
the
dryer,
it
may
not
have
a
control
device,
meaning
that
the
entire
setup
may
not
be
in
compliance
with
the
proposed
PCWP
rule.
However,
there
are
three
possible
scenarios
for
the
actual
emissions
from
this
setup
and
similar
configurations,
and
all
three
point
to
the
conclusion
that
the
combustion
unit
does
not
need
to
undergo
initial
compliance
tests
or
control
requirements.
In
the
first
scenario,
a
process
dryer
is
fed
by
emissions
from
any
source
and
the
exhaust
is
fed
to
a
control
device.
The
control
device
would
ensure
at
least
90
percent
destruction
efficiency,
and
testing
the
burner
would
be
unnecessary.
In
the
second
scenario,
the
burner
of
a
process
dryer
is
fed
by
emissions
from
a
noncredit
generating
source
such
as
a
press,
and
the
dryer
meets
the
requirements
of
the
PBCO.
The
dryer
emissions
would
include
the
HAP
created
by
the
dryer
and
the
undestroyed
HAP
from
the
burner.
Presumably,
to
meet
the
PBCO,
destruction
of
press
vent
emissions
would
need
to
meet
or
exceed
the
90
percent
destruction
efficiency
requirement.
EPA
should
allow
the
facility
to
meet
the
PBCO
limit
plus
10
percent
of
the
press
emissions,
since
that
would
be
equivalent
to
90
percent
control.
The
third
scenario
is
similar
to
the
second,
except
the
dryer
is
fed
by
a
creditgenerating
source
such
as
a
blender.
Since
the
burner
exhaust
cannot
be
measured
directly,
EPA
should
provide
a
method
for
counting
the
credits
generated
by
destroying
the
HAP
from
that
source.
The
facility
could
measure
the
dryer
outlet
and
subtract
10
percent
of
credit
generation
rate
to
determine
compliance
with
the
PBCO.
This
approach
would
give
100
percent
credit
for
2­
182
destruction
of
the
credit­
generation
emission,
whereas
the
proposed
rule
does
not
allow
for
credits
based
on
more
than
90
percent
destruction.
Alternatively,
the
rule
could
just
require
that
the
PBCO
be
met
with
no
credit
given
for
emissions
from
the
credit­
generating
source
that
were
not
destroyed
in
the
process
burner.
This
approach
would
assume
100
percent
destruction
of
the
credit­
generating
emission
and
then
only
90
percent
would
be
applied
to
the
PBCO.
In
any
case,

regardless
of
the
heat
capacity
input,
none
of
the
combustion
units
would
need
to
be
tested,
and
the
commenters
requested
that
the
following
phrases
be
added
to
the
PCWP
rule:

40
C.
F.
R.
§
63.2260(
a)
[
add]
.
.
.
Process
heaters
used
to
oxidize
emissions
from
presses
or
other
sources
that
exhaust
into
dryers
are
exempt
from
the
initial
performance
testing
requirements
for
thermal
oxidizers.
63.2262(
d)
Location
of
sampling
sites.
(
1)
For
testing
control
devices
located
prior
to
final
discharge
to
the
atmosphere,
sampling
sites
must
be
located
at
the
inlet
of
the
control
sequence
and
at
the
outlet
of
the
control
device
prior
to
any
releases
to
the
atmosphere.
(
2)
For
testing
control
devices
located
between
process
units,
such
as
process
burners,
sampling
sites
must
be
located
at
the
inlet
of
the
control
sequence.
(
3)
Sampling
sites
for
process
based
emission
limits
in
Table
1A
are
to
be
located
prior
to
any
releases
to
the
atmosphere.

Finally,
the
commenter
provided
an
alternative
to
the
exemption
requested
above
for
combustion
units
with
a
heat
capacity
of
less
than
44
MW.
If
these
units
must
be
tested,
the
test
method
should
be
able
to
distinguish
between
the
HAP
generated
by
the
combustion
unit
and
the
HAP
generated
by
other
parts
of
the
process.
During
the
90
percent
reduction
performance
test,

the
combustion
emissions
should
be
tested
first
separate
from
the
process
unit
emissions
and
then
with
those
emissions.
If
the
difference
between
the
two
emission
measurements
is
not
statistically
significant,
then
the
combustion
unit
is
in
compliance.
The
description
of
a
similar
test
is
located
at
40
CFR
60,
appendix
C.

Response:
As
noted
by
the
commenter,
the
HON
(
subpart
G)
and
the
final
Pulp
and
Paper
MACT
I
rule
(
subpart
S)
exempt
from
testing
and
monitoring
requirements
combustion
devices
with
heat
input
capacity
greater
than
or
equal
to
44
MW.
The
HON
also
exempts
from
testing
and
monitoring
combustion
devices
with
capacity
less
than
44
MW
if
the
exhaust
gas
to
be
controlled
enters
with
the
primary
fuel.
If
the
exhaust
gas
to
be
controlled
does
not
enter
with
the
primary
fuel,
then
testing
and
continuous
monitoring
of
firebox
temperature
is
required
by
the
HON.
Similarly,
the
final
Pulp
and
Paper
MACT
I
rule
(
subpart
S)
exempts
from
testing
and
monitoring
requirements
combustion
devices
(
including
recovery
furnaces,
lime
kilns,
boilers
or
2­
183
process
heaters)
with
capacity
less
than
44
MW
if
the
exhaust
stream
to
be
controlled
enters
into
the
flame
zone
or
with
the
primary
fuel.
Based
on
the
precedent
established
in
the
HON
and
Pulp
and
Paper
MACT
I
rules,
the
final
PCWP
rule
extends
the
exemption
from
testing
and
monitoring
requirements
to
combustion
units
with
heat
input
capacity
less
than
44
MW,
provided
that
the
exhaust
gas
to
be
treated
enters
into
the
combustion
unit
flame
zone.
If
the
exhaust
gas
enters
into
the
combustion
unit
flame
zone,
the
required
90
percent
control
efficiency
may
be
assumed.

If
the
exhaust
gas
does
not
enter
into
the
flame
zone,
then
the
testing
and
monitoring
requirements
for
thermal
oxidizers
will
apply.
Given
that
few
combustion
units
would
require
testing,
the
final
rule
does
not
specify
how
to
differentiate
between
the
HAP
generated
by
the
combustion
unit
and
the
HAP
generated
by
other
parts
of
the
process.
Facilities
may
petition
the
Administrator
to
determine
if
such
differentiation
will
be
allowed,
and
how
to
measure
to
emissions.

Regarding
the
first
scenario
presented
by
the
commenters
(
where
a
process
dryer
is
fed
by
emissions
from
any
source
and
the
exhaust
is
fed
to
a
control
device),
we
agree
that
the
control
device
would
ensure
at
least
90
percent
destruction
efficiency,
and
testing
the
burner
would
be
unnecessary.

The
second
operating
scenario
presented
by
the
commenters
involves
a
dryer
burner
used
to
control
press
emissions,
while
the
dryer
meets
the
PBCO.
We
believe
that
the
commenter's
suggestion
of
allowing
the
facility
to
meet
the
dryer
PBCO
plus
10
percent
of
the
press
emissions
is
overly
complicated.
The
final
PCWP
rule
already
contains
three
sets
of
compliance
options
(
six
add­
on
control
system
compliance
options,
PBCO
limits
for
each
process
unit,
and
emissions
averaging).
We
believe
that
adding
additional
provisions
for
combining
compliance
options
for
the
numerous
potential
process
unit
and
control
system
exhaust
configurations
would
complicate
the
rule
to
the
point
that
enforcability
of
the
rule
would
be
hampered.
Therefore,
a
source
with
a
dryer
used
to
control
press
emissions
that
chooses
to
comply
with
the
PBCO
must
meet
the
dryer
PBCO
as
stated
in
the
final
rule
and
would
not
be
allowed
to
account
for
any
uncombusted
press
emissions.
The
press
emissions
routed
to
the
dryer
burner
would
be
assumed
to
be
reduced
by
90
percent,
provided
that
the
press
emissions
are
introduced
into
the
dryer
burner's
flame
zone.

The
third
operating
scenario
presented
by
the
commenters
involves
routing
exhaust
from
an
emissions
averaging
credit­
generating
unit
(
e.
g.,
blender)
to
a
dryer
burner
while
the
dryer
complies
with
the
PBCO.
In
this
scenario,
the
uncontrolled
blender
emissions
would
be
measured
2­
184
prior
to
entering
the
dryer
burner.
For
purposes
of
calculating
emissions
averaging
credits,
the
blender
emissions
directed
to
the
dryer
burner
would
be
assumed
to
be
reduced
by
90
percent,

provided
that
the
blender
emissions
are
introduced
into
the
dryer
burner's
flame
zone.
We
disagree
that
the
dryer
PBCO
should
be
changed
to
accommodate
the
blender
emissions
for
two
reasons.
First,
as
noted
for
scenario
2
above,
altering
the
PBCO
to
account
for
process
emissions
added
to
the
dryer
burner
would
introduce
unnecessary
complexity
to
the
rule.
Second,
the
final
rule
does
not
allow
combining
of
emissions
averaging
and
the
PBCO
as
discussed
previously
in
sections
2.6.3
and
2.6.4
of
this
document.

The
wording
we
incorporated
into
the
final
rule
is
less
specific
than
the
wording
suggested
by
the
commenter;
however,
it
still
accomplishes
the
goal
of
exempting
from
the
testing
and
monitoring
requirements
combustion
units
that
accept
process
exhausts
into
the
flame
zone.
We
have
also
included
definitions
of
"
flame
zone"
and
"
combustion
unit"
in
the
final
rule.

2.7.13
Selection
of
biofilter
monitoring
parameters
2.7.13.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
agreed
that
temperature
is
a
parameter
that
should
be
monitored
for
biofilters,
but
argued
that
the
location
of
the
temperature
monitor
should
be
changed
from
the
biofilter
inlet
to
the
biofilter
bed.
The
bed
temperature
has
the
greatest
impact
on
biological
activity.
The
biofilter
inlet
temperature
is
not
a
good
indicator
of
the
bed
temperature
and
can
change
very
rapidly
depending
on
the
operating
rate
of
the
press,

the
humidity,
and
the
ambient
temperature.
Although
biofilters
can
operate
in
a
wide
range
of
temperatures,
it
is
important
to
make
sure
that
the
biofilter
remains
in
that
range
to
support
biological
activity
and
maintain
performance
level.
For
that
reason,
the
temperature
should
be
monitored
at
an
alternate
location,
such
as
the
biofilter
bed,
the
biofilter
outlet,
or
the
support
media
for
the
biological
material.
To
compensate
for
low
inlet
temperatures
due
to
low
humidity,

some
biofilters
have
supplemental
heat
added
to
the
humidifier.
However,
EPA
can
not
require
that
facilities
measure
humidifier
inlet
temperature,
because
some
systems
do
not
have
a
humidifier.
The
commenter
requested
that
EPA
change
the
temperature
monitoring
location
to
the
biofilter
exhaust
or
the
biological
media/
bed.

Response:
We
agree
with
the
commenter
that
the
biofilter
bed
temperature
has
the
greatest
impact
on
biological
activity
and
that
the
location
for
monitoring
the
biofilter
temperature
should
be
changed.
We
did
not
propose
monitoring
of
biofilter
bed
temperature
because
we
thought
that
monitoring
of
biofilter
inlet
temperature
would
be
simpler
because
only
one
2­
185
thermocouple
would
be
required.
The
temperature
inside
the
biofilter
bed
can
change
in
different
areas
of
the
bed,
and
therefore,
depending
on
the
biofilter,
multiple
thermocouples
may
be
necessary
to
get
an
accurate
picture
of
the
temperature
conditions
inside
the
biofilter
bed.
Prior
to
proposal
we
rejected
the
idea
of
monitoring
the
biofilter
exhaust
temperature
because
temperature
measured
at
this
location
can
be
affected
by
ambient
temperature
(
especially
for
biofilters
with
short
stacks)
more
than
the
temperature
inside
the
biofilter
bed.
Thus,
we
now
conclude
that
there
is
no
better,
more
representative
way
to
monitor
the
temperature
to
which
the
biofilter
microbial
population
is
exposed
than
to
directly
monitor
the
temperature
of
the
biofilter
bed.
According
to
our
MACT
survey
data,
most
facilities
with
biofilters
are
already
monitoring
biofilter
bed
temperature.
Therefore,
the
final
rule
requires
continuous
monitoring
of
the
temperature
inside
the
biofilter
bed.

We
acknowledge
that
biofilter
bed
temperature
can
vary
with
seasonal
conditions,
and
that
the
biofilter
can
reduce
HAP
within
a
relatively
wide
temperature
range
(
e.
g.,
70
to
100
°
F).

Biofilters
are
currently
located
in
different
areas
of
the
United
States,
including
the
upper
Midwest
and
the
South.
Biofilter
bed
temperature
is
a
controllable
parameter;
the
exhaust
stream
entering
the
biofilter
can
be
cooled
through
humidification
or
heated
using
steam
as
necessary
to
maintain
the
biofilter
bed
within
its
optimal
temperature
range.
However,
we
believe
that
the
optimal
temperature
range
for
individual
biofilters
is
based
on
site
specific
conditions
(
e.
g.,
type
of
media
and
microbes,
climate
at
the
facility,
whether
the
biofilter
is
located
above
or
below
ground).
Therefore,
we
believe
it
is
appropriate
that
the
temperature
range
for
each
individual
biofilter
be
verified
through
emissions
testing.
Facilities
experiencing
large
seasonal
variations
in
their
biofilter
bed
temperatures
may
choose
to
expand
their
temperature
operating
range
by
conducting
performance
tests
during
winter
and
summer
months.

The
proposed
rule
would
have
allowed
facilities
to
specify
their
own
monitoring
methods,

monitoring
frequencies,
and
averaging
times
for
the
proposed
biofilter
operating
parameters
(
i.
e.,

inlet
temperature,
effluent
pH,
and
pressure
drop).
However,
as
discussed
elsewhere
in
section
2.7.13,
for
the
final
rule
we
have
reduced
the
biofilter
parameters
to
be
monitored
to
temperature
only.
Monitoring
of
temperature
is
not
as
subjective
as
monitoring
biofilter
effluent
pH
and
pressure
drop,
and
therefore,
as
an
outgrowth
of
our
decision
not
to
require
monitoring
of
biofilter
effluent
pH
and
pressure
drop,
the
final
rule
specifies
the
monitoring
method,
frequency,

and
averaging
time
for
biofilter
bed
temperature
monitoring.
The
final
rule
requires
that
each
2­
186
thermocouple
be
placed
in
a
representative
location,
and
clarifies
that
multiple
thermocouples
may
be
used
in
different
locations
within
the
biofilter
bed.
The
temperature
data
(
e.
g.,
average
temperature
across
all
the
thermocouples
located
in
the
biofilter
bed
if
multiple
thermocouples
are
used)
must
be
monitored
continuously
and
reduced
to
a
24­
hour
block
average.
A
24­
hour
block
average
was
selected
for
biofilter
temperature
monitoring
because
we
recognize
that
there
may
be
some
diurnal
variation
in
temperature.
Facilities
wishing
to
reflect
a
diurnal
temperature
variation
when
establishing
their
biofilter
temperature
may
wish
to
perform
some
test
runs
during
peak
daily
temperatures
and
other
test
runs
early
in
the
morning
when
temperatures
are
at
their
lowest.

2.7.13.2
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
the
operating
requirements
for
pressure
drop
across
the
biofilter
bed
should
be
removed
from
the
PCWP
rule.

Pressure
drop
is
a
good
parameter
to
monitor
voluntarily
because
it
indicates
the
permeability
and
age
of
the
biofilter
bed,
which
helps
determine
maintenance
and
replacement
needs.
However,
it
is
not
an
indicator
of
destruction
efficiency.
Because
of
normal
wear
and
tear,
the
pressure
drop
gradually
increases
over
the
two
to
five
year
life
span
of
the
biofilter,
so
it
would
not
be
possible
to
maintain
a
constant
operating
pressure.
Monitoring
pressure
drop
should
only
demonstrate
that
a
biofilter
is
operating
within
the
design
specifications.
The
commenter
noted
that
the
OAQPS
Background
Information
Document
(
BID)
for
the
Proposed
Plywood
and
Composite
Wood
Products
NESHAP
only
mentions
pressure
drop
as
an
indication
of
age
and
life
of
the
filter
bed,
but
it
does
not
provide
proof
that
pressure
drop
indicates
destruction
efficiency.
The
three
documents
referenced
by
the
BID,
Summary
of
the
Responses
to
the
1998
EPA
Information
Collection
Request
(
MACT
Survey)
­
General
Summary
(
Docket
II­
B­
30),
Proposed
Monitoring
Protocol
for
Biofiltration
Systems
From
the
Forest
Products
Industry
(
II­
D­
495),
and
Minutes
of
the
August
5,
1998
Meeting
with
Envirogen,
Inc.
(
II­
E­
15),
do
not
support
the
idea
that
pressure
drop
indicates
control
efficiency,
but
they
do
support
the
idea
that
pressure
drop
indicates
age
and
life
of
the
biofilter
bed.
The
third
source
listed
does
discuss
a
situation
in
which
a
biofilter
became
clogged
and
efficiency
decreased,
but
the
manufacturer
found
that
inlet
temperature
change
was
to
blame,
not
the
pressure
drop
in
the
biofilter
bed.
The
current
PCWP
rule
does
not
allow
for
the
normal
increase
in
pressure
drop,
but
simply
monitoring
the
pressure
drop
would
indicate
when
maintenance
is
needed.
If
biofilter
pressure
drop
remains
a
mandatory
control
parameter,

facilities
will
be
forced
to
change
the
biofilter
media
before
the
end
of
its
useful
life.
During
the
times
that
the
biofilter
is
being
replaced,
a
large
amount
of
HAP
escapes
to
the
atmosphere,
so
2­
187
changing
the
bed
more
often
could
result
in
a
net
increase
in
HAP.
An
absolute
limit
on
pressure
drop
is
impractical,
since
action
is
only
necessary
when
the
pressure
drop
increases
rapidly
from
current
conditions.
Facilities
could
be
allowed
to
retest
existing
biofilters
when
they
reach
the
end
of
their
useful
lives
to
determine
the
new
operating
range.
Since
the
results
from
compliance
tests
performed
before
a
modification
cannot
be
used
to
set
operating
limits
on
the
modified
unit,
a
new
operating
range
could
only
be
determined
in
this
manner
if
changing
a
biofilter
bed
or
media
type
is
not
considered
a
modification
of
the
biofilter.

Response:
We
agree
with
the
commenters
that
increases
in
pressure
drop
will
occur
over
time
and
will
not
necessarily
equate
to
a
reduction
in
control
efficiency,
making
an
absolute
limit
on
pressure
drop
ineffective
in
demonstrating
continuous
compliance.
Therefore,
we
have
removed
the
requirement
to
monitor
pressure
drop
from
the
operating
requirements
for
biofilters
in
the
final
PCWP
rule.

2.7.13.3
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
the
operating
requirements
for
pH
of
the
biofilter
bed
effluent
should
be
removed
from
the
PCWP
rule.
The
commenters
noted
that
pH
is
a
good
parameter
to
monitor
voluntarily
because
it
indicates
the
environmental
conditions
inside
the
biofilter
bed
and
can
indicate
the
presence
of
organic
acids
and
THC
decomposition
products,
but
it
is
not
a
reliable
indicator
of
destruction
efficiency.
If
other
environmental
factors
are
favorable,
a
pH
between
6.0
and
7.5
is
sufficient
to
allow
the
existing
microorganisms
to
oxidize
the
organic
material
and
sustain
biological
activity.
The
pH
within
a
biofilter
system
tends
to
regulate
itself
well,
and
small
fluctuations
of
pH
are
expected
and
have
little
effect
on
the
biofilter
performance.
However,
the
narrow
range
of
pH
values
that
would
be
established
as
an
operating
range
by
the
initial
compliance
tests
should
not
be
used
alone
to
determine
biofilter
performance
or
the
need
for
major
adjustments.
Those
major
adjustments
are
only
needed
if
the
pH
falls
below
6.0.
Another
issue
with
monitoring
biofilter
pH
is
the
ability
to
continuously
monitor
that
parameter.
Some
biofilter
units
operate
with
periodic
irrigation
of
the
bed,
meaning
that
the
effluent
is
not
constant
and
continuous
monitoring
is
not
possible.

Attempting
to
irrigate
these
types
of
beds
continuously
would
block
mass
transfer
and
severely
reduce
the
performance
of
the
biofilter.
Because
the
effluent
is
not
continuous,
there
is
no
good
location
for
measuring
the
pH
of
a
biofilter,
and
monitoring
a
stagnant
sample
of
water
certainly
would
not
achieve
the
goal.
The
commenters
pointed
to
an
NCASI
survey
that
confirmed
that
pH
monitoring
would
be
impractical
for
the
facilities
surveyed.
Further,
since
none
of
the
facilities
2­
188
surveyed
could
find
a
link
between
pH
alone
and
biofilter
production,
none
of
those
facilities
currently
have
pH
monitors
on
their
biofilters.
If
a
facility
chooses
to
measure
this
parameter,

readings
should
only
be
taken
once
a
week,
and
calibration
should
not
be
performed
more
often
then
that.
The
pH
changes
fairly
slowly,
so
recording
the
pH
frequently
is
unnecessary.

Commenter
IV­
D­
03
suggested
that
checking
the
pH
meter
calibration
quarterly
rather
than
every
eight
hours
would
be
a
lot
more
realistic
and
would
relieve
a
large
burden
of
monitoring
time,

labor,
recordkeeping,
and
other
factors.

Response:
Although
pH
is
an
indicator
of
the
health
of
the
microbial
population
inside
the
biofilter,
we
agree
with
the
commenters
that
including
continuous
pH
monitoring
as
an
operating
requirement
for
biofilters
may
not
be
appropriate.
We
acknowledge
that
there
is
not
a
good
location
for
continuously
measuring
pH
in
some
biofilters
and
that
pH
is
not
necessarily
a
reliable
indicator
of
destruction
efficiency.
Therefore,
we
have
removed
the
requirement
to
monitor
pH
from
the
operating
requirements
for
biofilters
in
the
final
PCWP
rule.
We
have
also
deleted
the
pH
meter
calibration
procedures
that
commenter
IV­
D­
03
refers
to
from
the
rule.

2.7.13.4
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
requested
that
EPA
give
facilities
some
flexibility
in
choosing
the
biofilter
operating
parameters
that
will
be
subject
to
operating
ranges
and
controls.
Many
facilities
that
currently
operate
biofilters
measure
the
temperature
and
pressure,
along
with
other
physical
characteristics,
but
the
readings
are
only
observed,
and
not
subject
to
limits.
To
demonstrate
HAP
removal,
most
of
these
facilities
use
periodic
stack
testing
or
CEMS
for
THC.
Since
biofilters
have
not
been
in
use
long
enough
for
a
thorough
study
of
monitoring
requirements,
EPA
should
leave
room
in
the
PCWP
rule
to
allow
facilities
to
monitor
and
control
the
parameters
that
they
feel
best
demonstrate
compliance.
The
commenter
agreed
that
outlet
temperature
could
be
an
acceptable
parameter
for
control.

Response:
We
have
eliminated
the
proposed
requirements
for
monitoring
biofilter
pressure
drop
and
pH,
and
we
have
revised
the
biofilter
temperature
monitoring
requirement.
The
only
parameter
required
to
be
monitored
and
controlled
for
the
final
PCWP
rule
is
biofilter
bed
temperature.
Facilities
may
choose
to
observe
other
parameters,
but
will
not
be
required
to
record
or
control
them
for
the
PCWP
rule.
We
believe
that
many
factors
can
affect
biofilter
performance,
either
alone
(
e.
g.,
a
media
change)
or
in
concert
with
one
another
(
e.
g.,
a
loss
of
water
flow
resulting
in
a
sharp
change
in
temperature
and
pH),
and
the
factors
that
have
the
greatest
effect
on
biofilter
performance
are
likely
to
be
site
specific.
However,
based
on
the
2­
189
comments
we
have
received,
we
conclude
that
extensive
biofilter
parameter
monitoring
is
not
the
best
method
for
ensuring
continuous
compliance.
Therefore,
to
promote
enforceability
of
the
PCWP
rule,
we
have
added
a
requirement
to
perform
repeat
testing
of
biofilters.
The
final
rule
requires
facilities
to
conduct
a
repeat
test
every
two
years
and
every
time
they
replace
at
least
50
percent
(
by
volume)
of
the
biofilter
media.
Each
repeat
test
must
be
conducted
within
two
years
of
the
previous
test
(
e.
g.,
two
years
after
the
initial
compliance
test,
or
two
years
after
the
test
following
a
media
change).
Facilities
using
a
THC
CEMS
that
choose
to
comply
with
the
THC
compliance
options
(
i.
e.,
90
percent
reduction
in
THC
or
outlet
THC
concentration
less
than
or
equal
to
20
ppmvd)
may
use
the
data
from
their
CEMS
in
lieu
of
conducting
repeat
performance
testing.

2.7.13.5
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
replacing
the
biofilter
media
should
not
be
considered
a
modification
of
the
biofilter.
The
frequency
of
replacement
can
be
as
often
as
two
years,
and
it
is
unnecessary
for
facilities
to
establish
new
operating
ranges
every
time
the
media
is
replaced.
Instead,
the
operating
range
used
for
the
previous
bed
should
be
appropriate
for
the
replacement
bed.
The
EPA
may
choose
to
require
one
test
to
confirm
that
the
new
bed
is
still
operating
within
the
same
range
after
the
bed
is
acclimated.
The
wording
of
section
63.2262(
m)(
2)
(
How
do
I
conduct
performance
tests
and
establish
operating
requirements?
­
Establishing
biofilter
operating
requirements)
indicates
that
EPA
does
not
consider
the
replacement
of
a
biofilter
bed
to
be
in
the
same
category
as
new
biofilters.
The
commenters
requested
that
the
following
sentence
be
added
to
section
63.2262(
m)(
1):

"
Replacement
of
biofilter
media
with
the
same
type
of
material
is
not
considered
a
modification
for
purposes
of
this
paragraph."

Response:
We
agree
that
facilities
replacing
the
biofilter
media
with
any
amount
of
the
same
type
of
media
should
not
be
required
to
reestablish
their
biofilter
bed
temperature.
Section
63.2262(
m)(
1)
of
the
proposed
rule
stated
that
"
If
you
use
data
from
previous
performance
tests,

you
must
certify
that
the
biofilter
and
associated
process
unit(
s)
have
not
been
modified
subsequent
to
the
date
of
the
performance
tests"
(
emphasis
added).
We
agree
that
it
is
appropriate
to
use
data
from
previous
performance
tests
to
establish
the
biofilter
bed
temperature
range
when
the
biofilter
has
not
been
"
modified"
in
a
way
that
will
affect
its
long­
term
performance.
We
believe
that
substantial
replacement
of
the
biofilter
media
(
i.
e.,
replacement
of
50%
or
more
of
the
biofilter
bed)
with
the
same
type
of
media
may
affect
short­
term
performance
2­
190
of
the
biofilter
while
the
replacement
media
becomes
acclimated.
Therefore,
to
ensure
that
the
media
is
acclimated,
the
final
PCWP
rule
requires
a
repeat
performance
test
within
180
days
following
replacement
of
50
percent
or
more
(
by
volume)
of
biofilter
media
with
the
same
type
of
media.
We
have
added
the
sentence
suggested
by
the
commenters
to
§
63.2262(
m)(
1)
to
indicate
that
a
new
biofilter
bed
temperature
range
need
not
be
established
following
replacement
of
the
biofilter
bed
media
with
the
same
type
of
material.
During
repeat
testing
following
replacement
with
the
same
type
of
media,
facilities
can
verify
that
their
biofilter
remains
within
the
temperature
range
established
previously
or
establish
a
new
compliant
temperature
range.

As
discussed
in
response
to
comment
No.
2.7.13.6
below,
for
purposes
of
§
63.2262(
m)(
1)­(
3)
we
do
consider
replacing
the
biofilter
media
with
another
type
of
media
as
a
"
modification"
of
the
biofilter
that
necessitates
establishment
of
a
new
biofilter
bed
temperature
range.
The
final
PCWP
rule
requires
facilities
to
conduct
a
repeat
performance
test
following
every
replacement
of
the
biofilter
media
with
any
volume
of
a
different
media
(
e.
g.,
if
the
media
is
changed
from
bark
to
synthetic
material).
Facilities
using
a
different
type
of
media
must
reestablish
their
temperature
range.

2.7.13.6
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
EPA
should
allow
new
biofilters
a
longer
period
than
180
days
to
establish
operating
parameter
levels.
The
commenters
suggested
a
one­
year
period,
since
that
would
be
long
enough
to
observe
the
full
seasonal
variation
in
parameters
and
find
the
true
operating
maxima
and
minima.
For
example,
it
is
not
very
likely
that
180
days
would
be
long
enough
to
observe
the
complete
temperature
range
within
which
biofilters
can
effectively
remove
water­
soluble
HAP.
Section
63.2262
(
m)(
2)
(
How
do
I
conduct
performance
tests
and
establish
operating
requirements?
­
Establishing
biofilter
operating
requirements)
should
be
completely
replaced
by
the
following
section:

(
2)
If
historical
operating
records
are
not
readily
available
for
new
biofilters,
biofilters
that
have
been
physically
modified,
or
biofilters
with
media
replaced
with
a
new
or
different
type
of
media,
you
will
be
allowed
up
to
1
year
following
the
compliance
date
to
gather
and
complete
the
requirements
of
paragraph
(
m)(
1)
of
this
section.

A
long
establishment
period
would
also
allow
the
biofilter
to
become
completely
acclimated
and
provide
a
better
understanding
of
its
regular
operation.
Since
biofilters
have
a
slow
response
time,
compliance
testing
under
different
conditions
does
not
give
reliable
results.
Instead
the
best
ways
to
determine
operating
ranges
for
a
new
biofilter
are
to
accept
data
from
previous
biofilters
2­
191
or
observe
the
performance
of
the
unit
for
a
year.
If
a
facility
has
to
establish
a
pressure
drop
operating
range,
the
period
of
time
to
establish
that
range
would
be
much
longer
than
a
year.
An
appropriate
operating
range
would
need
to
be
based
on
the
pressure
drop
at
the
end
of
the
life
span
of
the
biofilter.
The
commenter
stated
that
waiting
that
long
to
establish
compliance
parameters
is
impractical,
and
the
situation
provides
another
argument
for
omitting
pressure
drop
requirements
from
the
PCWP
rule.

Response:
We
disagree
that
more
than
180
days
is
necessary
to
establish
operating
parameter
limits
for
biofilters.
As
mentioned
previously,
we
have
eliminated
the
proposed
requirement
to
establish
operating
limits
for
pH
and
pressure
drop.
The
final
PCWP
rule
contains
two
options
for
biofilter
operating
parameter
limits:
biofilter
bed
temperature
range,
and
outlet
THC
concentration.
While
allowing
one
year
to
establish
the
biofilter
bed
temperature
operating
range
is
reasonable
due
to
seasonal
temperature
variations,
1
year
is
not
necessary
for
establishing
an
outlet
THC
concentration
limit.
Furthermore,
the
final
PCWP
rule
already
allows
facilities
to
expand
their
operating
ranges
(
see
§
63.2262(
m)(
3))
through
additional
emissions
testing.

The
compliance
date
for
existing
facilities
is
3
years
after
promulgation
of
the
final
PCWP
rule,
and
existing
facilities
are
allowed
180
days
following
the
compliance
date
to
conduct
performance
testing
and
establish
the
operating
parameter
limits.
If
there
is
concern
that
180
days
is
not
long
enough
for
a
new
biofilter
installation
to
operate
under
the
full
range
of
biofilter
bed
temperatures,
then
existing
facilities
begin
operation
of
their
biofilter
well
before
the
compliance
date
(
e.
g.,
180
days
prior
to
the
compliance
date
if
1
year
is
needed).
Facilities
also
have
the
option
of
testing
their
biofilter
prior
to
the
compliance
date
to
establish
one
extreme
of
their
biofilter
bed
temperature
range.
The
compliance
date
for
new
PCWP
facilities
is
the
effective
date
of
the
rule
(
if
startup
is
before
the
effective
date)
or
upon
initial
startup
(
if
the
initial
startup
is
after
the
effective
date
of
the
rule),
and
biofilters
installed
at
new
PCWP
facilities
would
have
up
to
180
days
following
the
compliance
date
to
establish
the
operating
parameter
limits.
To
address
situations
where
a
new
biofilter
is
installed
at
an
existing
facility
more
than
180
days
after
the
compliance
date
(
e.
g.,
to
replace
an
existing
RTO),
we
have
included
section
§
63.2262(
m)(
2)

in
the
final
PCWP
rule,
which
allows
existing
sources
that
install
new
biofilters
up
to180
days
following
the
initial
startup
date
of
the
biofilter
to
establish
the
operating
parameter
limits.
Thus,

new
biofilter
installations
(
i.
e.,
those
with
initial
startup
dates
after
the
compliance
date)
are
given
2­
192
time
for
establishment
of
operating
parameter
limits
regardless
of
where
they
are
installed
at
new
or
existing
sources.

2.7.14
Continuous
THC
monitoring
2.7.14.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
supported
the
option
to
continuously
monitor
THC
at
control
device
outlets
to
demonstrate
compliance,
but
stated
that
either
the
procedure
for
determining
the
operating
limits
or
the
length
of
the
averaging
periods
needs
to
be
altered.
The
THC
concentration
at
a
control
device
outlet
is
not
a
parameter
that
can
be
easily
adjusted
by
operators.
The
concentration
is
mainly
influenced
by
the
THC
content
in
the
wood,
which
is
dependent
on
the
location
and
age
of
the
timber,
the
season,
and
the
length
of
time
between
cutting
the
timber
and
drying
the
wood.
These
are
not
factors
that
can
be
directly
changed
by
operators
over
short
periods
of
time
just
to
maintain
a
certain
THC
concentration.
A
different
method
is
needed
to
determine
whether
or
not
a
facility
is
in
compliance.
The
proposed
PCWP
rule
requires
that
the
operating
limits
be
set
as
the
average
of
the
three
highest
15­
minute
block
reporting
periods
during
the
3­
hour
compliance
demonstration
emission
test.
However,
the
commenter
stated
that
based
simply
on
the
variability
of
the
process,
three
hours
is
not
a
long
enough
block
to
avoid
deviations
from
compliance.
The
commenter
provided
a
table
of
analyzed
THC
data
from
a
biofilter
outlet.
The
table
showed
multiple
deviations
occurring
over
the
twomonth
period
after
compliance
when
a
3­
hour
block
set
the
operating
limits
and
few
to
zero
deviations
when
a
24­
hour
or
7­
day
block
set
the
operating
limits.
In
order
to
avoid
numerous
deviations
under
the
proposed
PCWP
rule,
a
mill
would
have
to
try
to
set
the
operating
limits
when
emissions
are
at
a
maximum,
but
that
situation
occurs
less
than
5
percent
of
the
time
that
the
device
is
operating.
The
commenter
recommended
adopting
the
7­
day
block
average
because
it
provides
a
better
overall
picture
of
the
control
device
performance.
Since
HAP
destruction
efficiency
of
biofilters
does
not
vary
much
with
time,
the
longer
block
would
not
be
environmentally
dangerous.
Alternatively,
EPA
could
establish
a
24­
hour
block
operating
limit
as
the
highest
1­
hour
average
THC
reading
in
the
week
preceding
and
following
the
compliance
demonstration
test.

Response:
While
THC
emissions
at
the
outlet
of
a
biofilter
may
vary,
the
THC
emissions
at
the
outlet
of
an
thermal
or
catalytic
oxidizer
should
not
vary
greatly.
Although,
as
stated
by
the
commenters,
the
HAP
destruction
efficiency
of
biofilters
is
not
subject
to
large
short­
term
variations,
the
same
is
not
true
for
thermal
and
catalytic
oxidizers
(
e.
g.,
a
sudden
significant
2­
193
decrease
in
temperature
could
result
in
a
sudden
decrease
in
HAP
reduction).
Therefore,
we
believe
it
is
appropriate
to
maintain
the
3­
hour
block
averaging
requirement
for
THC
monitoring
for
thermal
and
catalytic
oxidizers.
However,
we
have
expanded
the
THC
averaging
requirement
for
biofilters
to
a
24­
hour
block
average
to
provide
more
flexibility.
The
THC
operating
limit
for
biofilters
would
be
established
as
the
maximum
of
three
15­
minute
recorded
readings
during
emissions
testing.
We
also
note
the
continuous
monitoring
of
THC
is
not
required
for
all
APCD,

but
is
an
alternative
to
continuous
monitoring
of
temperature.
Furthermore,
facilities
can
conduct
multiple
performance
tests
at
different
operating
conditions
to
increase
their
maximum
THC
concentration
operating
limit.

2.7.15
Selection
of
monitoring
parameters
for
uncontrolled
process
units
2.7.15.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
recommended
changing
the
title
of
section
63.2262
(
n)
(
How
do
I
conduct
performance
tests
and
establish
operating
requirements?
­
Establishing
uncontrolled
process
unit
operating
requirements)
to
"
Establishing
operating
requirements
for
production
based
compliance
option
process
units."
The
current
title
implies
that
no
controls
of
any
kind
are
being
applied
to
these
process
units,
when
in
fact
facilities
may
be
voluntarily
controlling
these
units
or
using
P2
techniques
to
reduce
emissions.
Also,
the
wording
within
the
section
itself
assumes
that
controlling
the
temperature
is
the
only
method
of
reducing
emissions.
The
commenter's
suggested
changes
to
the
section
are
shown
below:

(
n)
Establishing
operating
requirements
for
production
based
compliance
option
process
units:
Establishing
uncontrolled
process
unit
operating
requirements.
If
you
operate
a
process
unit
that
meets
a
compliance
option
in
Table
1A
of
this
subpart
without
the
use
of
a
control
device,
you
must
establish
your
process
unit
operating
parameters
according
to
paragraphs
(
n)(
1)
through
(
2)
of
this
section.
(
1)
During
the
initial
performance
test,
you
must
identify
and
document
continuously
monitor
the
process
unit
controlling
parameter(
s)
critical
to
maintaining
compliance
with
the
limits
listed
in
Table
1A
of
this
subpart.
For
example,
if
the
controlling
parameter
is
inlet
temperature
or
operating
temperature,
(
whichever
applies,
as
specified
for
different
process
units
in
Table
2
of
this
subpart)
during
the
initial
performance
test,
you
must
continuously
monitor
the
process
unit
during
each
of
the
required
1­
hour
test
runs.
The
maximum
inlet
temperature
or
maximum
operating
temperature
must
would
then
be
established
as
the
average
of
the
three
maximum
15­
minute
temperatures
monitored
during
the
three
test
runs.
Limits
for
other
controlling
will
be
established
using
the
same
method.
Multiple
3­
run
performance
tests
may
be
conducted
to
establish
a
range
of
parameter
values
under
different
operating
conditions.
(
2)
You
may
establish
a
different
operating
parameter
range
maximum
temperature
for
your
process
unit
by
submitting
the
notification
specified
in
§
63.2280(
g)
and
conducting
a
2­
194
repeat
performance
test
as
specified
in
paragraph
(
n)(
1)
of
this
section
that
demonstrates
compliance
with
the
compliance
options
in
Table
1A
of
this
subpart.

If
these
changes
are
made,
then
the
following
adjustments
would
have
to
be
made
to
Table
2
to
Subpart
DDDD:

(
5)
Process
unit
that
meets
a
compliance
option
in
Table
1A
of
this
subpart
Maintain
the
controlling
operating
parameter
3­
hour
block
average
inlet
temperature
below
the
maximum
inlet
temperature
established
during
the
performance
test
if
for
the
process
unit
is
a
green
rotary
dryer,
tube
dryer,
or
strand
dryer;
OR
maintain
the
3­
hour
block
average
process
unit
operating
temperature
below
the
maximum
operating
temperature
established
during
the
performance
test
if
the
process
unit
is
a
hardboard
oven,
press
predryer,
or
reconstituted
wood
product
press;
OR
maintain
the
3­
hour
block
average
operating
temperature
in
each
of
the
hot
zones
below
the
maximum
hot
zone
temperatures
established
during
the
performance
test
if
the
process
unit
is
a
fiberboard
mat
dryer
or
softwood
veneer
dryer.
Maintain
the
3­
hour
block
average
THC
concentration
a
in
the
process
unit
exhaust
below
the
maximum
concentration
established
during
the
performance
test
Response:
There
are
two
situations
in
the
PCWP
rule
where
process
units
may
not
have
an
add­
on
control
device:
(
1)
when
process
units
meet
the
PBCO,
or
(
2)
when
process
units
used
to
generate
emissions
averaging
debits
do
not
have
an
add­
on
APCD
that
partially
controls
emissions.
To
clarify
this
for
the
final
rule
and
to
address
the
commenters
concern
regarding
applicability
of
§
63.2262(
n),
we
changed
the
title
of
the
section
to
"
Establishing
operating
requirements
for
process
units
meeting
compliance
options
without
a
control
device."

We
agree
with
the
commenters
that
temperature
alone
is
not
necessarily
the
sole
controlling
parameter
for
some
process
units.
The
final
rule
requires
testing
at
representative
operating
conditions,
defined
in
the
rule
as
"
operation
of
a
process
unit
during
performance
testing
under
the
conditions
that
the
process
unit
will
typically
be
operating
in
the
future,

including
use
of
a
representative
range
of
materials
(
e.
g.,
wood
material
of
a
typical
species
mix
and
moisture
content
or
typical
resin
formulation)
and
representative
operating
temperature
range."
The
rule
requires
facilities
to
describe
their
representative
operating
conditions
in
each
performance
test
report
for
the
process
and
control
systems
and
explain
why
these
conditions
are
2­
195
representative
(
see
§
63.2262(
b)(
2)).
The
process­
unit­
specific
conditions
identified
in
each
test
report
as
being
"
representative"
would
be
the
most
appropriate
conditions
to
record
for
process
units
without
controls.
We
recognize
that
it
is
not
practical
to
continuously
monitor
every
process­
unit­
specific
factor
that
could
affect
uncontrolled
emissions
(
e.
g.,
there
is
not
way
to
monitor
and
determine
a
3­
hour
block
average
of
wood
species
mix
for
a
particleboard
plant).

However,
some
parameters
are
suitable
for
continuous
monitoring
(
e.
g.,
process
operating
temperature,
furnish
moisture
content)
and
are
already
monitored
as
part
of
normal
operation,
but
not
for
compliance
purposes.
We
believe
that
daily
records
of
most
parameters
would
be
sufficient
to
ensure
ongoing
compliance
(
e.
g.,
daily
average
process
operating
temperature,

furnish
moisture,
resin
type,
wood
species
mix)
if
the
parameters
do
not
deviate
from
the
ranges
for
these
parameters
during
the
initial
compliance
test.
Therefore,
in
the
final
PCWP
rule,
we
have
replaced
the
proposed
3­
hour
block
average
temperature
monitoring
requirements
for
process
units
without
control
devices
with
a
requirement
to
maintain
on
a
daily
basis
the
process
unit
controlling
operating
parameter(
s)
within
the
ranges
established
during
the
performance
test.

This
allows
facilities
the
flexibility
to
decide
which
parameters
they
will
monitor
and
control,

while
providing
enforcement
records
with
which
to
assess
and
compare
the
day­
to­
day
operation
of
the
process
unit
to
the
controlling
operating
parameters.
Facilities
are
also
allowed
to
decide
for
each
parameter
the
appropriate
monitoring
methods,
monitoring
frequencies,
and
averaging
times
(
not
to
exceed
24
hours)
for
continuously
monitored
parameters
such
as
temperature
and
wood
furnish
moisture.

We
also
note
that
the
commenters
suggested
removing
the
option
of
monitoring
THC
concentration
instead
of
process
unit
operating
parameters.
While
we
believe
it
is
unlikely
that
facilities
with
uncontrolled
process
units
would
elect
to
monitor
THC,
we
have
retained
this
as
an
option
in
the
final
rule
because
this
alternative
is
offered
for
all
of
the
other
operating
requirements.

2.7.16
Performance
specifications
for
temperature
monitors
2.7.16.1
Comment:
Commenters
IV­
D­
03,
IV­
D­
21,
and
IV­
D­
27
made
a
few
suggestions
for
revising
the
sections
discussing
temperature
measurement.
First,
the
phrase
"
minimum
tolerance
of
0.75
percent"
found
in
sections
63.2268(
b)(
2),
63.2268(
c)(
3),
and
63.2268(
e)(
2)
should
be
revised
to
read
"
accurate
within
0.75
percent
of
sensor
range."
These
commenters
stated
that,
because
tolerances
usually
refer
to
physical
dimensions,
this
revision
2­
196
more
accurately
reflects
the
intent
of
the
PCWP
rule.
Commenter
IV­
D­
03
recommended
that
the
temperature
sensor
tolerance
be
adjusted
to
1
percent
of
the
temperature
range.
Second,

commenters
IV­
D­
21
and
IV­
D­
27
stated
that
the
phrase
"
of
at
least
20
°
F"
found
in
section
63.2268(
b)(
3)
should
be
replaced
with
"
minor
divisions
of
not
more
than
20
°
F."
The
current
wording
means
that
minor
divisions
could
be
30
°
F
or
50
°
F,
but
since
EPA
probably
means
that
20
°
F
is
the
largest
minor
division
that
a
facility
can
use,
the
suggested
revision
is
more
accurate.

Commenter
IV­
D­
27
also
stated
that
the
thermocouple
calibration
and
inspection
requirements
are
too
strict.
The
PCWP
rule
should
be
revised
to
consider
any
reading
within
50
°
F
of
the
process
temperature
sensor's
reading
adequate.
Commenter
IV­
D­
27
further
stated
that
quarterly
inspections
on
thermocouples
should
not
be
required.
The
commenter
noted
that
the
only
way
to
completely
perform
these
inspections
is
to
withdraw
the
thermocouple
from
its
location
in
the
combustion
chamber.
This
often
causes
damage
to
the
sensor,
requiring
it
to
be
replaced.
If
a
thermocouple
provides
readings
that
correspond
with
other
thermocouple
readings,

then
the
thermocouple
should
be
considered
valid.

Response:
We
acknowledge
that
the
term
"
tolerance"
is
often
used
to
mean
accuracy
in
the
sense
of
physical
dimensions.
Therefore,
we
have
changed
the
requirement
in
§
63.2269(
b)(
2)

(
formerly
proposed
§
63.2268(
b)(
2))
to
read
"
minimum
accuracy
of
0.75
percent
of
the
temperature
value."
As
discussed
below,
we
eliminated
proposed
sections
§
§
63.2268(
c)
and
63.2268(
e)
from
the
final
rule
because
we
deleted
the
requirements
for
monitoring
of
pressure
or
flow.
As
requested
by
the
commenters,
we
also
revised
proposed
§
63.2268(
b)(
3)
to
state
that
"
If
a
chart
recorder
is
used,
it
must
have
a
sensitivity
with
minor
divisions
of
not
more
than
20
°
F."

We
disagree
that
the
proposed
thermocouple
calibration
and
inspection
requirements
are
too
strict
and
we
have
not
changed
these
requirements
for
the
final
rule.
We
further
disagree
that
the
requirement
for
the
temperature
sensor
to
agree
with
the
reading
of
a
redundant
sensor
within
30
°
F
during
a
calibration
check
is
too
stringent.
The
sensor
is
required
to
be
"
accurate"
within
0.75
percent
of
the
measured
temperature.
Measurements
from
redundant
temperature
sensors
with
0.75
percent
accuracy
should
differ
by
not
more
than
1.5
percent
(
and
rarely
by
this
much).

If,
for
example,
the
temperature
being
monitored
is
1600
°
F,
1.5
percent
is
less
than
25
°
F
which
is
well
within
the
30
°
F
allowance.
2­
197
2.7.17
Performance
specifications
for
pressure
monitors
2.7.17.1
Comment:
Commenters
IV­
D­
03,
IV­
D­
21,
and
IV­
D­
27
suggested
a
few
changes
for
revising
the
section
on
pressure
monitoring
(
63.2268(
c)).
Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
the
instrument
tolerance
should
be
1.0
inch
of
water
for
a
gauge
or
a
minimum
of
2
percent
of
the
pressure
range
for
a
transducer.
These
values
are
realistic
for
the
commonly
used
instrumentation
in
the
industry.
Second,
daily
checks
for
plugging
of
pressure
taps
are
unnecessary.
If
pressure
monitoring
is
included
in
the
PCWP
rule,
facilities
should
be
required
to
include
pressure
tap
plugging
in
a
maintenance
program
and
encouraged
to
develop
effective
methods
of
plugging
detection,
such
as
a
computer­
based
alarm
system.
Commenter
IVD
03
stated
it
would
be
excessive
and
potentially
unsafe
to
check
pressure
taps
for
plugging
daily,

and
suggested
a
check
of
the
pressure
reading
to
ensure
that
it
is
normal
and
not
stagnant.

Commenter
IV­
D­
03
stated
that
pressure
instrumentation
should
not
be
limited
to
manometers
only;
alternatives
should
include
instruments
such
as
an
NIST­
traceable
calibrator.
This
commenter
recommended
that
both
the
pressure
calibrator
and
the
transducer
output
should
be
checked
on
a
quarterly
basis.
Commenter
IV­
D­
27
stated
that
facilities
should
not
be
required
to
use
a
manometer
to
check
the
calibration
of
the
pressure
gauge,
and
instead,
EPA
should
require
a
validation
check
between
the
two
gauges
with
acceptance
criteria
of
0.75
inches
of
water.

Response:
We
have
removed
all
pressure
monitoring
requirements
from
the
PCWP
rule.

(
Note
that
proposed
§
63.2268
was
renumbered
§
63.2269
for
the
final
rule.)

2.7.18
Performances
specifications
for
flow
monitors
2.7.18.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
disagreed
with
a
few
of
the
requirements
for
flow
monitoring
(
section
63.2268(
e)
­
What
are
my
monitoring
installation,

operating,
and
maintenance
requirements?
­
Flow
monitoring).
First,
the
2
percent
minimum
tolerance
for
the
flow
rate
measurements
is
too
low,
and
it
is
not
supported
by
the
MACT
floor.

According
to
manufacturers'
specifications,
the
flow
rate
sensors
used
on
dryer
and
press
exhausts
only
have
an
accuracy
of
±
5
percent
to
±
7
percent.
The
repeatability
is
only
±
0.5
percent.
Adjusting
the
accuracy
and
repeatability
of
a
sensor
is
not
possible
since
the
systems
are
designed
and
set
by
the
manufacturer.
Field
adjustments
for
specific
flow
conditions
such
as
temperature
can
be
made,
so
there
is
a
need
to
conduct
flow
relative
accuracy
test
audits
(
RATA)

at
a
certain
frequency
to
verify
that
the
monitor
is
operating
properly.
The
EPA
should
allow
facilities
to
achieve
±
10
percent
accuracy
to
ensure
that
compliance
will
be
met.
This
value
is
2­
198
used
in
EPA
Method
2
for
manual
measurements
of
pitot
tubes.
Commenter
IV­
D­
27
further
stated
that
checking
the
flow
sensor
calibration
twice
a
year
for
both
pitot
tubes
and
thermal
convection
mass
flowmeters
is
not
necessary.
The
commenter
noted
that
industry
experience
indicates
that
comparing
the
flow
to
a
reference
method
test
on
the
same
periodicity
of
the
compliance
tests
required
by
the
facility's
permit
is
adequate
to
ensure
compliance.
Also,
facilities
can
compare
the
measured
flow
and
the
calculated
flow
rates
once
a
year
to
validate
the
sensor.

Commenter
IV­
D­
27
also
stated
that
inspection
of
flow
sensors
should
be
changed
from
four
times
a
year
to
once
a
year.
Industry
experience
has
shown
that
annual
inspection
is
enough
to
ensure
proper
operation.

Response:
We
have
removed
all
gas
flow
monitoring
requirements
from
the
PCWP
rule.

(
Note
that
proposed
§
63.2268
was
renumbered
§
63.2269
for
the
final
rule.)

2.7.19
Performance
specifications
for
moisture
monitors
2.7.19.1
Comment:
Commenter
IV­
D­
27
supported
EPA's
conclusion
that
dry
rotary
dryers,
hardwood
veneer
dryers,
and
veneer
redryers
have
inherently
low
HAP
emissions
and
thus
should
be
exempt
from
control
requirements
as
long
as
certain
work
practices
are
met.
The
commenter
specifically
supported
the
work
practices
for
hardwood
veneer
dryers,
softwood
veneer
dryers,
and
veneer
redryers
listed
in
Table
3
to
subpart
DDDD,
as
well
as
the
exemption
from
work
practice
requirements
for
facilities
required
by
some
other
regulatory
action
to
install
a
control
device
on
a
dry
rotary
dryer.
In
response
to
EPA's
request
for
comment
in
the
proposal
preamble
on
issues
related
to
the
work
practice
requirements,
the
commenter
recommended
that
EPA
allow
plants
more
flexibility
in
choosing
moisture
monitors.

Although
most
particleboard
plants
currently
use
near
infrared
(
NIR)
technology,

technologies
change
over
time,
so
EPA
should
specify
an
accuracy
limit
rather
than
a
specific
technology.
Monitor
choice
should
be
limited
to
units
with
a
±
1
percent
accuracy
capability
in
the
25
to
35
percent
moisture
content
range.
This
range
is
currently
met
by
NIR
technology
and
is
consistent
with
section
63.2268(
f)(
1)
(
What
are
my
monitoring
installation,
operation,
and
maintenance
requirements?
­
Wood
moisture
monitoring).
The
commenter
noted
that
the
accuracy
of
equipment
specification
is
typically
based
on
equipment
capabilities
and
measurements
taken
under
well
controlled
conditions.
Plants
strive
to
maintain
the
best
conditions
possible,
since
product
quality
depends
on
moisture
content,
but
conditions
outside
the
operators'
control
are
certain
to
be
a
factor
at
times.
The
commenter
argued
that
the
work
2­
199
practices
should
not
be
written
in
a
way
that
would
unnecessarily
restrict
dryer
operation
or
require
facilities
to
maintain
their
monitors
to
the
level
of
accuracy
indicated
by
monitor
specification
sheets.
For
moisture
monitors
at
the
outlet
of
softwood
veneer
dryers
and
the
inlet
of
veneer
redryers,
monitor
choices
should
be
limited
to
units
with
a
±
3
percent
accuracy
capability
in
the
15
to
25
percent
moisture
content
range.
Reliance
on
a
vendor's
certification
should
be
considered
adequate
for
demonstration
of
compliance
with
the
precision
requirement.

Commenters
IV­
D­
21
and
IV­
D­
27
objected
to
the
sampling
procedure
used
to
check
the
calibration
of
continuous
wood
moisture
content
monitors,
stating
that
the
procedure
in
proposed
§
63.2268(
f)(
3)
is
impractical.
The
moisture
content
of
the
wood
at
any
one
point
in
the
process
varies
so
much
that
a
truly
representative
sample
of
wood
would
have
to
be
fairly
large.
For
example,
a
representative
sample
of
veneer
would
require
multiple
sheets.
The
sheets
pulled
for
the
sample
would
not
pass
by
the
moisture
meter
because,
for
safety
reasons,
they
would
have
to
be
pulled
from
the
process
before
they
reached
the
redryer.
The
commenters
pointed
out
that
each
moisture
monitor
manufacturer
includes
calibration
procedures
in
the
operation
and
maintenance
recommendations
for
their
meters.
These
calibration
procedures
(
commonly
modified
to
meet
site­
specific
requirements)
will
correct
any
drift
that
occurs.
The
commenters
recommended
that
facilities
include
the
moisture
meter
manufacturer's
calibration
procedures
in
the
plant's
operation
and
maintenance
plan
and
follow
those
procedures
once
during
each
semiannual
compliance
reporting
period.
Adjustments
to
the
procedures
may
be
made
for
any
plant­
specific
needs.
Commenter
IV­
D­
27
attached
examples
of
moisture
monitor
manufacturer's
calibration
procedures.

Commenter
IV­
D­
27
requested
that
the
ASTM
D1037
test
method
be
added
to
the
list
of
test
procedures
referenced
in
the
rule.
This
test
method
should
be
the
default
method
for
moisture
analysis
and
calibration
of
machines
used
to
analyze
grab
samples,
as
well
as
continuous
moisture
monitors
(
recognizing
that
moisture
monitor
manufactures
may
have
alternative
methods
for
calibrating
their
equipment).
The
reference
should
be
added
to
section
63.2268(
f)
(
What
are
my
monitoring
installation,
operation,
and
maintenance
requirements?
­
Wood
moisture
monitoring).
The
PCWP
rule
should
use
the
ASTM
D1037
method
for
setting
grab
sample
requirements,
which
recommends
drying
the
wood
sample
"
until
approximately
constant
weight
is
attained."
The
drying
time
is
not
specified
because
wood,
sample
size,
and
lab
variability
factors
make
the
constant
weight
timing
difficult
to
predict.
The
regulation
should
go
no
further
than
2­
200
specifying
that
either
this
test
method
be
used
or
a
moisture
analyzer
calibrated
by
this
test
method
be
used.
More
specific
guidance
and
examples
can
be
included
in
implementation
documents
rather
than
in
the
national
rule.
The
commenter
attached
a
copy
of
ASTM
D1037.

Response:
Proposed
§
63.2268
was
renumbered
§
63.2269
for
the
final
rule.
We
proposed
requirements
for
the
continuous
moisture
sensor
and
grab
sampling
in
§
63.2268(
f).
We
noted
in
the
preamble
to
the
proposed
rule
that
we
planned
to
add
to
§
63.2268(
f)
performance
specifications
for
the
continuous
moisture
sensor
to
include
such
parameters
as
the
amount
of
drift
allowed.
We
requested
comment
on
drift
and
any
other
performance
specifications
that
should
be
added
to
ensure
moisture
content
is
being
measured
accurately,
to
ensure
flexibility
in
the
type
of
continuous
moisture
sensor
that
can
be
used
by
a
facility,
and
to
ensure
compliance
and
enforceability.
We
also
stated
in
the
proposal
preamble
that
we
planned
to
add
specifications
to
the
grab
sample
requirements,
such
as
including
the
period
of
time
a
sample
must
maintain
a
constant
weight.
We
requested
comment
on
what
this
period
of
time
should
be
and
any
other
specifications
that
should
be
added
to
ensure
accurate
and
precise
results.

We
acknowledge
the
commenters'
support
of
the
work
practice
requirements
for
dry
rotary
dryers,
hardwood
veneer
dryers,
softwood
veneer
dryers,
and
veneer
redryers.
In
response
to
the
commenters'
suggestions,
we
have
modified
the
work
practice
requirements
for
moisture
monitoring
in
the
final
rule;
these
changes
are
discussed
in
subsequent
paragraphs.
In
addition
to
the
changes
regarding
moisture
monitoring,
the
final
rule
also
exempts
from
the
work
practice
requirements
those
PCWP
facilities
that
elect
to
designate
their
dry
rotary
dryer
as
a
green
rotary
dryer,
and
thus
elect
to
meet
the
standards
for
green
rotary
dryers
which
are
more
stringent
than
the
work
practice
standards
for
dry
rotary
dryers.
The
same
exemption
is
provided
for
PCWP
facilities
that
elect
to
designate
their
hardwood
veneer
dryer
or
veneer
redryer
as
a
softwood
veneer
dryer,
and
thus
elect
to
meet
a
more
stringent
standard.

Based
on
the
feedback
provided
by
the
commenter,
we
have
revised
proposed
§
63.2268(
f)(
1)
to
specify
that
moisture
monitors
used
at
the
inlet
of
dry
rotary
dryers
must
have
a
minimum
accuracy
of
1
percent
(
dry
basis)
in
the
25
to
35
percent
(
dry
basis)
moisture
content
range,
and
that
moisture
monitors
used
at
the
inlet
of
veneer
redryers
must
have
minimum
accuracy
of
3
percent
(
dry
basis)
in
the
15
to
25
percent
(
dry
basis)
moisture
content
range.

Alternatively,
facilities
may
use
a
moisture
monitor
with
a
minimum
accuracy
of
5
percent
(
dry
basis)
moisture
or
better
for
dry
rotary
dryers
used
to
dry
furnish
with
less
than
25
percent
(
dry
2­
201
basis)
moisture
or
for
veneer
redryers
used
to
redry
veneer
with
less
than
20
percent
(
dry
basis)

moisture.

We
have
also
revised
proposed
§
63.2268(
f)(
3)
to
eliminate
the
proposed
grab
sample
procedure
for
calibration
of
continuous
moisture
monitors
and
to
specify
that
continuous
moisture
monitors
must
be
calibrated
based
on
the
procedures
specified
by
the
moisture
monitor
manufacturer
at
least
once
per
semiannual
compliance
period
(
or
more
frequently
if
recommended
by
the
moisture
monitor
manufacturer).
Because
we
dropped
the
grab
sample
requirements,
we
clarified
that
all
moisture
measurements
must
be
on
a
dry
basis
to
prevent
facilities
from
using
a
wet
basis
(
e.
g.,
30
percent
moisture
on
a
dry
basis
is
equivalent
to
23
percent
moisture
on
a
wet
basis).
We
added
an
equation
to
the
rule
to
convert
from
wet
basis
moisture
content
to
dry
basis
moisture
content
(
as
needed).
We
did
not
incorporate
the
ASTM
D1037
test
method
into
the
rule
because
no
method
for
determining
grab
sample
moisture
content
is
needed.

2.7.20
Work
practice
requirements
for
dryers
2.7.20.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
noted
that
Table
8
to
subpart
DDDD
(
Continuous
Compliance
with
the
Work
Practice
Requirements)
does
not
include
averaging
periods
for
work
practice
requirements,
and
stated
that
EPA
needs
to
add
those
where
applicable.

Response:
We
revised
Table
8
to
subpart
DDDD
to
restate
the
averaging
periods
for
the
dry
rotary
dryer
and
veneer
redryer
work
practices.

2.7.20.2
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
noted
that
although
the
equation
to
determine
the
percent
reduction
through
a
control
device
includes
a
term
for
capture
efficiency,

the
method
for
determining
that
efficiency
for
dryers
is
not
specified
in
the
PCWP
rule.
The
capture
efficiency
for
rotary
dryers
should
be
assumed
to
be
100
percent,
and
it
should
be
assumed
to
be
100
percent
for
veneer
dryers
as
long
as
the
facility
follows
the
work
practices
listed
in
Table
3
to
subpart
DDDD.
The
floor
for
capture
efficiency
for
dryers
was
not
determined,
but
the
emission
data
provided
to
EPA
assumed
that
the
efficiency
was
100
percent.

The
EPA
cannot
establish
that
the
floor
must
be
100
percent
capture
efficiency
if
it
does
not
have
the
data
to
support
that
requirement.
Commenter
IV­
D­
43
suggested
that
hardboard
ovens
be
treated
like
softwood
veneer
dryers
in
terms
of
determining
capture
efficiency.
If
work
practices
are
followed,
then
the
capture
efficiency
should
be
assumed
to
be
100
percent.
Hardboard
ovens
were
not
specifically
covered
in
the
rule,
and
clarification
of
the
situation
is
necessary.
2­
202
Response:
We
agree
that
the
capture
efficiency
for
dryers
and
hardboard
ovens
is
typically
100
percent
because
those
dryers
operate
under
negative
pressure
and
exhaust
from
these
dryers
is
directed
through
a
stack.
For
some
types
of
dryers,
the
negative
pressure
air
flow
acts
to
pneumatically
convey
the
wood
material
through
the
dryer
as
well
as
to
prevent
emissions
leakage
and
minimize
buildup
of
combustible
gases.
For
hardboard
ovens,
a
loss
of
negative
pressure
would
lead
to
product
quality
problems.
We
also
agree
that
the
capture
efficiency
for
veneer
dryers
can
be
assumed
to
be
100
percent
as
long
as
the
facility
follows
the
work
practices
listed
in
Table
3
to
subpart
DDDD.
Process
units
that
may
have
less
than
100
percent
capture
are
presses
or
board
coolers
with
partial
wood
products
enclosures.
In
equations
where
capture
efficiency
(
CE)
is
a
variable,
the
rule
defines
CE
as
"
capture
efficiency,
percent
(
determined
for
reconstituted
wood
product
presses
and
board
coolers
as
required
in
Table
4
of
this
subpart)."

Thus,
the
capture
efficiency
term
does
not
apply
for
dryers
or
other
process
equipment
with
assumed
100
percent
capture.

2.7.20.3
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
recommended
changing
the
averaging
period
for
inlet
moisture
and
temperature
monitoring
for
dry
rotary
dryers.
The
current
averaging
period
is
listed
as
24
hours
in
Table
3
to
subpart
DDDD
and
section
63.2268(
a)(
4)

(
What
are
my
monitoring
installation,
operation,
and
maintenance
requirements?
­
General
continuous
parameter
monitoring
requirements),
but
it
should
be
extended
to
a
period
chosen
by
the
individual
facilities
of
up
to
30
days.
Also,
plants
should
be
given
the
option
to
operate
green
rotary
dryers
as
dry
rotary
dryers.
This
option
provides
the
flexibility
to
implement
low
cost
options,
but
environmental
managers
need
certainty
that
they
can
meet
the
necessary
work
practice
requirements.
Extending
the
averaging
period
would
provide
the
operator
with
time
to
adjust
the
moisture
of
the
raw
material
purchased
or
coming
from
upstream
operations.
There
is
precedence
in
other
NESHAP
to
use
extended
averaging
periods
for
compliance
tests,
such
as
the
Leather
Finishing
NESHAP
(
Subpart
TTTT),
particularly
where
seasonal
factors
are
likely,
as
is
the
circumstance
here.
Several
other
factors
support
a
long
averaging
period
as
well.
Operators
and
producers
have
limited
control
over
short­
term
availability
of
the
raw
materials
chosen
for
the
plant,
and
the
weather
and
seasons
can
have
a
dramatic
effects
on
the
moisture
content
of
the
raw
material
over
a
one­
day
period.
Many
dryers
that
could
potentially
operate
as
dry
rotary
dryers
are
close
to
the
work
practice
limit,
and
a
longer
compliance
time
would
provide
more
certainty
about
the
results.
If
a
plant
has
a
large
amount
of
data,
then
the
standard
deviation
will
be
small
2­
203
and
the
plant
will
be
secure
with
the
resulting
decisions.
The
hourly
HAP
emissions
do
not
change
if
the
moisture
content
of
the
material
going
into
the
dryer
changes
because
the
work
practice
rules
for
dry
dryers
limit
the
dryer
inlet
temperature
to
600
°
F.
Finally,
the
inlet
moisture
restriction
is
meant
to
be
a
method
of
distinguishing
between
types
of
processes,
not
as
an
operating
restriction
that
assures
compliance
with
a
HAP
emission
limit.
Since
there
is
no
shortterm
emission
limit
for
demonstrating
compliance,
the
short­
term
compliance
monitoring
parameter
is
inappropriate.
Basically,
a
variability
in
raw
materials
does
not
translate
to
emission
variability,
and
therefore
does
not
require
compliance
monitoring
appropriate
to
assure
compliance
with
a
short­
term
emission
limit.

The
commenters
noted
that
the
preamble
to
the
PCWP
rule
states
that
green
rotary
dryers
and
dry
rotary
dryers
are
essentially
the
same
in
terms
of
equipment
design,
but
the
rule
does
not
allow
plants
to
permit
a
unit
that
is
nominally
a
green
rotary
dryer
with
controls
as
a
dry
rotary
dryer
without
control
requirements
under
an
alternative
operating
scenario.
This
option
should
be
specifically
addressed
in
the
final
rule.
Section
63.2263
(
Initial
compliance
demonstration
for
a
dry
rotary
dryer)
should
be
changed
to
read
as
follows:

If
you
operate
a
dry
rotary
dryer,
you
must
demonstrate
that
your
dryer
processes
furnish
with
an
inlet
moisture
content
of
less
than
or
equal
to
30
percent
(
by
weight,
dry
basis)
and
operates
with
a
dryer
inlet
temperature
of
less
than
or
equal
to
600
°
F.
You
must
designate
and
clearly
identify
each
unit
to
be
operated
as
dry
rotary
dryer.
You
must
choose
an
averaging
period
for
the
measurement
of
the
moisture
content
and
temperature
parameters
of
no
longer
than
30
days.
You
must
record
the
inlet
furnish
moisture
content
(
dry
basis)
and
inlet
dryer
operating
temperature
according
to
§
63.2268(
a),
(
b),
and
(
f)
for
a
minimum
of
3
averaging
periods
30
calendar
days.
You
must
submit
the
highest
recorded
24­
hour
average
inlet
furnish
moisture
content
and
the
highest
recorded
24­
hour
average
dryer
inlet
temperature
with
your
Notification
of
Compliance
Status.
In
addition,
submit
with
the
Notification
of
Compliance
Status
a
signed
statement
by
a
responsible
official
that
certifies
with
truth,
accuracy,
and
completeness
that
the
dry
rotary
dryer
will
dry
furnish
with
a
30
day
block
average
inlet
moisture
content
less
than
or
equal
to
30
percent
(
by
weight,
dry
basis)
and
will
operate
with
a
30
day
block
average
inlet
temperature
of
less
than
or
equal
to
600
°
F
in
the
future.

The
EPA
should
note
that
the
capital
expense
of
the
control
requirement
is
only
one
part
of
the
expense
equation,
and
the
potential
to
eliminate
the
operating
costs
for
control
equipment
would
exist
by
allowing
this
option.
Since
the
moisture
in
the
raw
materials
does
change
based
on
the
weather
and
the
season,
the
option
would
give
more
regulatory
flexibility
to
plants
with
regular
swings
in
raw
material
moisture
above
and
below
30
percent.
Since
the
drier
material
would
2­
204
probably
be
available
in
the
summer,
the
option
to
switch
dryer
operation
would
allow
facilities
to
shut
off
NO
x­
generating
oxidizers
during
ozone
seasons
to
reduce
collateral
damage
to
the
environment.
On
the
other
hand,
the
moisture
content
demanded
by
market
could
decrease,
and
this
option
would
give
plants
the
flexibility
to
permit
units
both
ways
based
on
anticipated
changes.

Response:
We
believe
that
enforceability
of
the
rule
as
it
applies
to
rotary
particle
dryers
would
be
severely
hampered
if
we
were
to
incorporate
the
commenters'
suggestions
into
the
rule.

We
note
that
commenter
IV­
D­
27
specifically
requested
a
24­
hour
averaging
time
for
dry
rotary
dryer
moisture
monitoring
(
based
on
either
laboratory
analysis
of
grab
samples
or
continuous
inline
moisture
meters)
in
their
white
paper
submitted
to
EPA
in
May
2001.27
We
granted
the
commenter's
request
for
a
24­
hour
averaging
time
prior
to
proposal
of
the
PCWP
rule.
We
maintain
that
a
24­
hour
averaging
time
is
enforceable
but
allows
flexibility
by
preventing
shortterm
slugs
of
high­
moisture
wood
from
causing
an
exceedance
of
the
30
percent
moisture
requirement.
We
extended
this
24­
hour
averaging
period
to
the
600
°
F
temperature
work
practice
for
dry
rotary
dryers.

We
do
not
believe
it
is
appropriate
to
allow
dryers
to
operate
green
rotary
dryers
at
some
times
and
dry
rotary
dryers
at
other
times,
especially
with
a
30­
day
averaging
period
for
the
moisture
and
temperature
work
practices.
A
30­
day
averaging
period
could
allow
facilities
to
operate
their
dry
rotary
dryer
as
a
green
rotary
dryer
for
up
to
half
of
the
days
in
the
averaging
period,
making
the
rule
virtually
unenforceable
with
respect
to
rotary
particle
dryers
and
causing
the
rule
not
to
achieve
the
emission
reduction
it
is
required
to
achieve
from
green
rotary
dryers.

The
same
would
be
true
of
any
averaging
period
more
than
24
hours.
The
final
rule
does
not
allow
facilities
to
operate
a
dryer
as
green
rotary
dryer
some
of
the
time
and
as
dry
rotary
dryers
at
other
times.
For
the
rule
to
be
enforceable,
there
must
be
a
clear
distinction
between
dry
rotary
dryers
and
green
rotary
dryers
(
given
that
dry
and
green
rotary
dryers
are
the
same
equipment
operated
differently).
Facilities
must
carefully
determine
which
dryers
they
will
distinguish
as
dry
rotary
dryers
considering
seasonal
variability
in
wood
moisture,
economics,
and
other
site­
specific
factors.
Plants
needing
the
flexibility
to
accommodate
highly
variable
furnish
moisture
may
find
it
more
economical
to
designate
all
of
their
dryers
as
green
rotary
dryers.
Although
the
final
rule
does
not
allow
dual
designation
of
a
dryer
as
both
a
dry
rotary
dryer
and
a
green
rotary
dryer,

facilities
from
may
change
the
designation
of
a
dryer
as
a
dry
rotary
dryer
or
a
green
rotary
dryer
2­
205
in
the
future.
Such
a
change
in
designation
could
be
made
through
the
appropriate
permitting
conduits.

2.7.20.4
Comment:
Commenter
IV­
D­
27
requested
clarification
on
the
compliance
methods
for
a
facility
that
decides
to
switch
from
drying
softwood
to
drying
hardwood.
The
current
proposal
of
the
PCWP
rule
establishes
a
MACT
floor
of
"
no
control"
for
existing
hardwood
veneer
dryers,
provided
they
have
been
drying
hardwood
for
a
year.
If
the
facility
switches
from
softwood
to
hardwood
at
least
a
year
before
the
promulgation
date
for
the
rule,

then
it
would
logically
follow
the
compliance
guidelines
for
hardwood
veneer
dryers.
However,
if
the
facility
makes
the
switch
after
the
compliance
date
for
the
PCWP
rule,
the
implication
is
that
the
facility
would
have
to
continue
to
operate
the
incineration
controls
for
a
year
after
they
are
no
longer
necessary.
To
clarify
and
remedy
the
situation,
the
commenter
suggested
that
EPA
allow
the
switch
from
softwood
to
hardwood
with
the
title
V
permit
restriction
that
the
material
dried
in
the
dryer
must
be
less
than
30
percent
softwood.
A
facility
would
then
follow
the
work
practice
requirements
associated
with
the
amounts
of
hardwood
and
softwood
dried
for
the
year
after
the
permit
went
into
effect.

Response:
The
final
rule
does
not
contain
language
to
allow
for
switching
back
and
forth
from
softwood
to
hardwood
veneer
drying
for
two
reasons.
First,
we
do
not
believe
there
will
be
widespread
switching
from
softwood
to
hardwood
veneer
drying
because
facilities
must
use
the
wood
supply
available
to
them,
and
because
product
characteristics
can
change
if
hardwoods
are
used
instead
of
softwoods.
Second,
allowing
dryers
to
operate
as
softwood
veneer
dryers
some
of
the
time
and
as
hardwood
veneer
dryers
at
other
times
would
make
the
rule
unenforceable
with
respect
to
veneer
dryers.
The
final
rule
requires
facilities
to
clearly
designate
their
veneer
dryers
as
either
softwood
veneer
dryers
or
hardwood
veneer
dryers
prior
to
the
compliance
date.

However,
the
final
rule
does
not
prevent
switching
designation
of
a
dryer
from
a
softwood
veneer
dryer
to
a
hardwood
veneer
dryer
after
the
compliance
date.
Such
a
change
in
designation
could
be
made
through
the
appropriate
permitting
conduits.
The
language
in
the
rule
requires
facilities
to
submit
with
their
Notification
of
Compliance
Status
"
the
annual
volume
percentage
of
softwood
species
dried
in
the
dryer
based
on
your
dryer
production
for
the
12
months
prior
to
the
compliance
date
specified
for
your
source
in
§
63.2233"
(
emphasis
added).
This
requirement
applies
before
the
compliance
date.
There
is
no
explicit
requirement
for
facilities
switching
designation
of
their
veneer
dryer
to
a
hardwood
veneer
dryer
after
the
compliance
date
to
2­
206
document
their
wood
species
for
12
months
before
their
dryer
is
considered
a
hardwood
veneer
dryer.

2.8
COMPLIANCE
DURING
PERIODS
OF
NON­
ROUTINE
OPERATION
2.8.1
Control
device
downtime
allowance
2.8.1.1
Comment:
Commenters
IV­
D­
19,
IV­
D­
21,
IV­
D­
23,
and
IV­
D­
27
supported
inclusion
of
a
routine
control
device
maintenance
exemption
(
RCDME)
in
the
PCWP
rule.

Commenter
IV­
D­
19
stated
that
experience
with
RTO
and
RCO
technology
since
1995
proves
routine
maintenance
is
the
only
way
to
maximize
the
life
of
the
devices,
especially
since
ten
years
of
research
have
not
solved
the
media
problems
that
this
technology
experiences.

Commenter
IV­
D­
27
stated
that
control
devices
used
to
reduce
HAP
emissions
in
the
PCWP
industry
require
significant
periodic
maintenance
because
the
emissions
contain
PM,

alkaline
salts,
and
acidic
compounds
that
rapidly
degrade
components
of
the
control
equipment.

These
conditions
are
not
present
in
other
industries
that
use
similar
equipment,
and
performing
the
necessary
maintenance
and
repairs
requires
significant
emission
control
downtime.
To
support
this
claim,
the
commenter
provided
an
NCASI
Technical
Bulletin
discussing
actual
data
from
RCO
and
RTO
usage
at
various
plants
and
the
required
maintenance
and
repairs.
If
the
downtime
allowance
is
not
adequate,
the
industry
will
lose
millions
of
dollars
associated
with
the
inability
to
continue
production
within
compliance
during
APCD
downtime.

Commenter
IV­
D­
23
also
noted
that
the
proposed
control
devices
were
designed
for
facilities
with
cleaner
air
streams,
such
as
chemical
plants,
and
the
PCWP
plants
that
use
these
control
technologies
will
need
time
for
more
frequent
cleaning
and
maintenance.

Response:
We
acknowledge
the
need
for
an
RCDME
for
the
PCWP
industry
and
have
included
such
an
exemption
in
the
final
rule.
As
explained
in
the
proposal
preamble,
the
most
widely
used
add­
on
control
systems
at
PCWP
facilities
are
RTOs,
RCOs,
and
biofilters.
As
with
any
control
device
in
any
industry,
these
control
devices
require
routine
maintenance.
Routine
maintenance
includes
activities
such
as
cleaning
or
replacement
of
corroded
parts,
media
replacement,
bakeouts
(
RTOs
and
RCOs),
washouts
(
RTOs
and
RCOs),
and
cleaning
of
ducts.

Some
PCWP
drying
processes
release
particulates
and
salts
that
can
plug
and
weaken
RTO
and
RCO
media
beds.
Frequent
bakeouts
and
washouts
are
necessary
to
combat
the
particulate
and
2­
207
salt
buildup.
Partial
or
total
media
replacement
is
done
when
bakeouts
and
washouts
are
no
longer
effective.
We
have
allowed
an
RCDME
for
the
PCWP
industry
to
ensure
that
facilities
will
perform
the
maintenance
necessary
to
ensure
that
their
APCDs
are
operated
properly.

2.8.1.2
Comment:
Commenters
IV­
D­
19,
IV­
D­
21,
IV­
D­
23,
and
IV­
D­
27
supported
the
RCDME
but
objected
to
the
discretionary
nature
of
the
exemption.
Commenters
IV­
D­
19
and
IV­
D­
21
objected
to
the
treatment
of
downtime
as
an
unusual
occurrence
rather
than
an
inherent
characteristic
of
the
wood
products
MACT
floor
control
technology.
The
frequency
of
the
necessary
maintenance
indicates
that
the
MACT
floor
includes
downtime
for
this
routine
maintenance.
Commenter
IV­
D­
19
stated
that
the
proposed
discretionary
downtime
allowance
increases
the
burden
on
state
Administrators
because
the
permitting
authorities
are
required
to
review
and
approve
downtime
requests.

Commenter
IV­
D­
27
argued
that
the
downtime
allowance
should
not
be
discretionary
and
that
each
affected
facility
should
not
be
required
to
request
a
routine
control
device
maintenance
exemption
from
the
Administrator.
The
commenter
pointed
out
that
in
similar
situations
(
e.
g.,
63
FR
18529
(
April
15,
1998)
for
the
Pulp
and
Paper
MACT
rule),
EPA
has
included
control
device
downtime
allowances
without
requiring
approval
from
the
Administrator.
The
wording
of
section
63.2251(
a)
(
What
are
the
requirements
for
the
routine
control
device
maintenance
exemption?)

implies
that
downtime
is
an
unusual
occurrence
rather
than
an
inherent
characteristic
of
the
control
technology.
Some
routine
maintenance
activities,
such
as
duct
cleaning,
valve
cleaning,

adjustment,
repair,
and
replacement
of
external
parts,
can
be
scheduled
to
coincide
with
planned
process
shutdowns,
but
events
such
as
offline
bakeouts,
washouts,
valve
cleaning,
and
media
replacement
must
be
performed
when
they
are
needed
or
the
control
devices
will
not
operate
properly.
When
emission
control
devices
need
repair,
the
repair
cannot
wait
until
an
annual
extended
process
outage,
especially
because
equipment
failures
that
result
from
these
repairs
not
being
completed
right
away
are
considered
preventable.
Also,
repairs
that
require
cooling
and
reheating
of
the
oxidizers,
such
as
media
replacement,
burner
repairs,
and
replacement
of
internal
corroded
parts
or
insulation,
will
take
longer
than
scheduled
process
outages.
The
EPA
recognized
that
frequent
maintenance
is
necessary,
but
it
should
have
made
the
downtime
exemption
automatic
rather
than
discretionary.
Because
of
the
nature
of
the
proposed
downtime
exemption,
the
request
for
exemption
will
be
a
standard
feature
of
any
permit
application
for
facilities
using
add­
on
controls,
creating
additional
work
for
the
permitting
agency
evaluating
the
2­
208
requests.
It
is
possible
that
the
granting
of
permission
for
the
exemptions
will
be
uneven
depending
on
the
State
and
a
company's
ability
to
prepare
and
submit
a
request
that
fully
explains
the
need
for
the
exemption.
Because
there
is
a
lack
of
back­
up
control
devices
and
routine
maintenance
must
be
performed
frequently,
EPA
should
include
downtime
for
routine
maintenance
in
the
MACT
floor.
The
commenter
argued
that
if
EPA
retains
its
approach
of
making
this
exemption
discretionary,
then
the
90
percent
control
requirement
that
EPA
has
identified
as
the
MACT
floor
is
simply
incorrect,
because
no
facility
achieves
a
steady
90
percent
removal
rate
over
a
several
year
period.
The
EPA
instead
would
need
to
recalculate
the
MACT
floor
to
reflect
the
actual
downtime
experienced
by
control
devices
in
this
industry,
and
prorate
the
percent
removal
requirement
(
and
concentration­
based
requirements)
to
incorporate
the
0
percent
removal
achieved
during
routine
maintenance.
The
EPA
also
would
need
to
modify
its
compliance
methodologies
to
assess
compliance
on
an
annual
basis
 
rather
than
the
3­
hour
average
that
currently
is
in
the
rule
 
to
account
for
the
sporadic
nature
of
equipment
downtime.

Obviously,
a
simpler
approach
is
to
include
a
control
device
downtime
provision
in
the
rule,

without
making
it
discretionary.

The
commenter
claimed
that
in
Sierra
Club
v.
EPA,
167
F.
3d
658,
665
(
D.
C.
Cir.
1999),

the
D.
C.
Circuit
decided
that
the
MACT
floor
should
represent
the
performance
of
the
best
performing
sources
"
under
the
most
adverse
circumstances
which
can
reasonably
be
expected
to
recur."
Downtime
is
an
"
adverse
circumstance,"
so
the
MACT
floor
for
wood
products
facilities
should
include
a
nondiscretionary
provision
for
control
equipment
downtime.
The
commenter
recommended
that
EPA
state
explicitly
in
the
final
rule
that
downtime
is
part
of
the
MACT
floor
determination
as
supported
by
the
record
and
that
sources
will
not
be
required
to
provide
justification
to
be
allowed
a
routine
control
device
maintenance
exemption.
Commenters
IV­
D­

21
and
IV­
D­
27
suggested
the
following
language
for
§
§
63.2251(
a)
and
(
c):

63.2251(
a).
Periods
of
deviation
from
compliance
options
in
§
63.2240(
b)
reported
under
§
63.2271
shall
not
be
a
violation
of
§
63.2240(
b)
provided
that
the
time
of
deviation
(
excluding
periods
of
start­
up,
shutdown,
or
malfunction)
in
an
annual
period
does
not
exceed
the
values
in
§
63.2251(
b).

63.2251(
c).
The
routine
control
device
maintenance
exemption
specified
in
§
63.2251(
a)
shall
be
incorporated
in
the
affected
source's
title
V
permit.
2­
209
Commenter
IV­
D­
07
suggested
that
instead
of
an
RCDME,
each
facility
should
be
required
to
write
and
submit
an
operation,
maintenance,
and
monitoring
(
OM&
M)
plan.
Anything
covered
in
the
plan
would
not
need
to
be
included
in
the
deviation
report,
but
anything
outside
of
the
plan
would
need
to
be
listed
in
the
deviation
report.
The
commenter
argued
that
the
proposed
downtime
allowance
amounts
to
a
lowering
of
the
bar
nationally
in
the
performance
expectation
for
the
industry,
whereas
site­
by­
site
plans
with
the
close
participation
of
the
enforcement
staff
of
the
permitting
authority
would
allow
a
better,
site­
specific
performance
expectation
to
be
developed
based
on
the
skills
and
abilities
of
each
facility.

Response:
We
believe
the
need
for
an
RCDME
is
site­
specific,
and
therefore,
we
maintain
that
the
RCDME
should
be
left
to
the
discretion
of
the
permitting/
enforcement
regulatory
agency.

As
one
commenter
has
pointed
out,
close
participation
of
the
permitting
and
enforcement
regulatory
agencies
is
needed
to
develop
site­
specific
performance
expectations.
Therefore,
the
final
rule
requires
facilities
to
submit
a
request
for
an
RCDME
for
approval
by
the
applicable
regulatory
authority.

We
disagree
that
the
90
percent
control
requirement
that
EPA
has
identified
as
the
MACT
floor
is
incorrect.
Our
data
indicate
that
several
control
devices
achieve
greater
than
90
percent
reduction.
The
90
percent
control
requirement
was
proposed
instead
of
a
more
stringent
percent
reduction
to
account
for
variability
in
control
system
performance
over
time
and
thus
already
accounts
for
reasonably
foreseen
adverse
circumstances.
Such
variability
in
performance
can
be
related
to
need
for
control
device
maintenance
(
e.
g.,
an
RTO
with
1­
year­
old
media
may
perform
less
effectively
than
an
RTO
with
new
media).

We
have
not
required
an
OM&
M
plan
because
OM&
M
plans
typically
include
all
monitoring
and
reporting
requirements,
not
just
the
requirements
associated
with
routine
control
device
maintenance.
Inclusion
of
an
OM&
M
plan
in
the
final
rule
would
have
required
rewriting
large
portions
of
the
proposed
rule.
Given
that
we
did
not
receive
many
requests
to
include
an
all­
inclusive
OM&
M
plan,
we
felt
it
would
cause
confusion
to
rewrite
the
proposed
rule
to
include
an
OM&
M
plan
prior
to
promulgation.

2.8.1.3
Comment:
Commenters
IV­
D­
21,
IV­
D­
23,
and
IV­
D­
27
argued
that
the
downtime
allowance
periods
are
too
short
to
allow
for
proper
maintenance.
Commenter
IV­
D­
23
stated
that
activities
that
are
performed
regularly
could
be
performed
in
that
time,
but
less
frequent
maintenance,
such
as
catalyst
replacement,
will
take
longer
than
the
allowed
downtime.
2­
210
Commenters
IV­
D­
21
and
IV­
D­
27
argued
that
downtime
allowance
for
rotary
dryers
needs
to
be
changed
to
better
represent
floor
technology.
The
3
percent
annual
downtime
allowance
was
based
on
the
assumption
that
maintenance
for
the
equipment
is
performed
annually.
However,
there
are
events
that
only
occur
every
2
to
3
years
and
require
an
extensive
amount
of
downtime,
such
as
replacing
the
heat
exchange
media
in
the
control
device
and
replacing
corroded
structural
parts.
According
to
an
NCASI
database,
the
median
life
of
RTO
heat
exchange
media
controlling
emissions
from
rotary
dryers
is
1.5
years,
and
80
percent
of
units
replaced
their
media
within
2
years.
The
survey
that
EPA
used
to
set
the
downtime
allowance
only
included
data
from
1999,
and
many
facilities
may
have
conducted
non­
annual
maintenance
and
repairs
in
the
years
preceding
or
following
that
year.
The
1999
survey
was
also
limited
in
that
the
majority
of
the
RTOs
included
in
the
survey
were
less
than
5
years
old,
and
as
the
equipment
ages
over
a
lifetime
of
5
to
15
years,
performance
will
degrade
below
the
levels
seen
in
the
1999
survey.
Facilities
are
likely
to
have
underreported
their
actual
downtime
in
the
original
survey,
so
increasing
the
downtime
would
be
more
representative
of
actual
experience.
The
commenters
argued
that
EPA
should
have
used
the
79th
percentile
of
the
annual
unscheduled
downtime
data
rather
than
the
50th
percentile
to
set
the
downtime
allowance.
The
50th
percentile
does
not
adequately
reflect
the
downtime
needs
for
non­
annual
activities,
but
the
79th
percentile
includes
the
downtime
needed
for
that
type
of
maintenance
and
repair
while
screening
out
the
maintenance
activities
associated
with
catastrophic
failures.
Scheduled
process
downtime
periods
are
too
short
for
a
maintenance
activity
that
requires
allowing
a
control
device
to
cool,
conducting
internal
repairs,
and
reheating
the
unit.
The
commenters
suggested
that
EPA
reexamine
the
downtime
data
and
use
the
79th
percentile
of
the
unscheduled
downtime
in
the
1999
NCASI
study
to
select
a
downtime
allowance
that
represents
the
time
needed
for
non­
annual
events.
Commenter
IV­
D­
27
stated
that
this
approach
is
justified
because
the
D.
C.
Circuit
stated
in
Sierra
Club
v.
EPA
that
the
MACT
floor
should
be
an
estimate
of
the
best­
controlled
sources
under
the
worst
conditions.
For
rotary
dryers,
the
79th
percentile
would
result
in
a
downtime
allowance
of
7.6
percent
of
annual
operating
hours.
Commenter
IV­
D­
21
noted
that,
alternatively,
EPA
could
allow
facilities
to
accumulate
unused
downtime
so
that
they
would
have
time
every
2
to
3
years
for
large
maintenance
activities.

Commenter
IV­
D­
27
stated
that
a
0.5
percent
downtime
allowance
for
softwood
veneer
dryers,
reconstituted
wood
product
presses,
reconstituted
wood
product
board
coolers,
hardboard
2­
211
ovens,
press
predryers,
and
fiberboard
mat
dryers
is
not
nearly
enough.
Assuming
a
plant
is
in
operation
a
full
8,760
hours
per
year,
0.5
percent
is
only
43.5
hours.
Annual
inspection
and
maintenance
for
small
control
units
may
be
accomplished
within
the
allowed
period,
but
larger
units
will
not
be
able
to
complete
all
maintenance
activities
within
this
downtime
allowance
period.
The
commenter
estimated
that
the
annual
maintenance
on
control
devices
that
serve
veneer
dryers
and
press
vents
would
take
41
hours
for
a
small
(
2­
chamber)
unit,
while
the
maintenance
for
a
large
(
6­
chamber)
unit
would
take
60
hours.
Some
of
the
steps
involved
in
that
estimate
include
removing
the
control
device
from
the
process,
cooling,
performing
various
maintenance
activities,
reheating
the
unit,
and
reconnecting
the
unit
to
the
process.
Again
referring
to
Sierra
Club
v.
EPA,
the
commenter
stated
that
the
proposed
downtime
for
veneer
dryers
and
presses
is
not
a
reasonable
estimate
of
the
best­
controlled
units
at
the
worst
conditions.

Also,
some
of
the
maintenance
can
be
performed
during
process
downtime,
but
when
one
control
device
controls
the
emissions
for
multiple
dryers
or
presses,
scheduling
becomes
more
difficult.

The
commenter
suggested
that
EPA
increase
the
downtime
allowance
for
maintaining
operation
of
RTO
units
treating
emissions
from
veneer
dryers
and
press
vents
to
60
hours
or
1
percent
of
operating
uptime,
whichever
is
greater.
This
value
represents
the
practical
minimum
amount
of
time
that
is
needed
to
perform
required
annual
maintenance
on
a
typical
combustion
APCD.

Commenter
IV­
D­
27
stated
that
biofilters
used
to
control
press
emissions
should
have
a
greater
downtime
allowance
than
the
0.5
percent
allowed
for
other
control
units
for
presses.
The
replacement
of
the
bed
media
is
the
most
significant
maintenance
activity
for
a
biofilter.
Because
the
volume
of
a
biofilter
bed
is
often
many
times
larger
than
the
heat
exchange
media
used
in
an
oxidizer,
and
the
media
is
equally
difficult
to
handle,
an
increase
in
the
downtime
exemption
is
justified.
An
industry
survey
indicates
that
it
takes
about
10
minutes/
cubic
yard
to
replace
biofilter
media,
so
replacing
a
2,000
cubic
yard
bed
would
take
approximately
two
weeks.

Fortunately,
while
bed
replacements
are
certainly
major
maintenance
events,
they
only
occur
every
two
to
four
years,
not
on
an
annual
basis.
To
accommodate
the
needs
of
a
biofilter,
the
commenter
suggested
that
the
routine
control
device
maintenance
exemption
for
a
biofilter
be
3
percent
of
operating
time.
In
addition,
EPA
should
provide
some
flexibility
in
this
section
that
would
better
accommodate
such
a
major
maintenance
activity
by
allowing
a
facility
to
accumulate
unused
maintenance
time
or
develop
a
rolling
three­
year
average.
That
flexibility
would
2­
212
encourage
facilities
to
better
manage
their
downtime
and
maintenance
schedules,
resulting
in
improved
equipment
uptime
and
performance.

Response:
In
2001,
the
PCWP
industry
submitted
to
EPA
results
of
a
survey
of
plants
operating
RTO,
RCO,
and
biofilters
to
determine
the
amount
of
process
unit
downtime
plants
incur
as
a
result
of
control
device
downtime.
28
These
data
were
used
by
industry
and
EPA
in
developing
the
proposed
downtime
allowance.
29
In
the
industry's
downtime
analysis,
six
routine
maintenance
downtime
categories
were
considered:
media
plugging,
media
degradation,

corrosion,
washouts,
offline
bakeouts,
and
other
cleaning.
Based
on
the
1999
data
reported
by
survey
respondents
for
30
RTO
and
RCO
controls,
the
industry
recommended
that
a
downtime
allowance
of
3.6
percent
of
process
unit
uptime
per
year
is
reasonable
for
all
PCWP
process
units.

In
analyzing
the
downtime
data,
the
industry
attempted
to
eliminate
the
effect
of
outliers
by
viewing
the
79th
percentile
value
as
representative
of
the
largest
amount
of
downtime
needed
by
the
best
controlled
sources.
The
industry
also
considered
downtime
allowances
for
different
process
units:
rotary
dryers
with
and
without
WESP
(
7.6
percent),
veneer
dryers
(
0.2
percent),

presses
(
0.9
percent),
and
tube
dryers
(
3.4
percent).

The
EPA
conducted
a
separate
analysis
of
the
industry's
downtime
survey
data
using
the
same
six
downtime
categories
because
these
categories
reflect
routine
maintenance
activities.
We
agreed
that
APCD
downtime
as
a
percentage
of
process
unit
uptime
was
the
most
appropriate
format
for
a
downtime
allowance.
Like
the
industry,
we
also
used
the
1999
downtime
data
for
the
30
RTO
and
RCO
controls.
These
downtime
data
represented
all
types
of
maintenance
activities
in
the
six
routine
maintenance
downtime
categories
(
media
plugging,
media
degradation,

corrosion,
washouts,
offline
bakeouts,
and
other
cleaning),
and
therefore
all
types
of
maintenance
activities
(
including
major
events)
were
represented
with
the
1999
downtime
data.
The
downtime
survey
requested
only
1999
process
uptime,
which
made
it
impossible
to
determine
downtime
as
a
percentage
of
process
uptime
for
years
other
than
1999.
Instead
of
the
79th
percentile
downtime
value,
we
used
central
tendencies
including
the
mean,
median,
and
the
mean
without
the
bottom
and
top
20
percent
of
the
data
(
i.
e.,
average
of
the
middle
60
percent
of
the
data).
The
79th
percentile
excludes
the
highest
of
the
reported
downtime
values,
but
still
represents
the
higher
end
of
the
range
of
downtime
needs.
We
believe
that
the
79th
percentile
downtime
value
would
overpredict
the
downtime
needed
for
two
reasons.
First,
the
1999
downtime
for
the
six
routine
maintenance
categories
was
reported
for
only
30
(
roughly
half)
of
the
RTO
and
RCO
control
2­
213
devices
included
in
the
downtime
survey.
Thus,
it
appears
that
up
to
half
of
the
RTO
and
RCO
included
in
the
survey
had
zero
downtime
in
1999
while
the
process
units
controlled
were
operating.
It
is
difficult
to
know
why
survey
respondents
did
not
report
1999
downtime
(
e.
g.,

because
the
control
device
had
zero
downtime,
or
the
control
device
was
not
operating
because
of
long
process
shutdown).
In
some
cases,
the
production
uptime
was
not
reported
and
could
not
be
used
in
determining
a
downtime
percentage.
Given
these
uncertainties,
the
0­
percent
downtime
values
were
not
evaluated.
Second,
the
downtime
allowance
must
apply
to
RTOs
and
RCOs
installed
in
the
future,
which
should
require
less
downtime
than
their
predecessors
because
of
design
improvements.

Based
on
our
analysis
(
and
also
apparent
from
the
industry
analysis),
we
determined
that
there
are
differences
in
the
percentages
of
downtime
needed
for
various
types
of
equipment.
The
RTO
and
RCO
used
on
veneer
dryers
and
presses
require
much
less
downtime
for
routine
maintenance
than
the
RTO
and
RCO
used
on
rotary
dryers
and
tube
dryers,
because
particulate
plugging
and
salt
deposition
problems
are
more
common
for
some
rotary
and
tube
dryers
than
for
presses
and
veneer
dryers.
Most
of
the
central
tendency
values
we
calculated
were
close
together
for
each
type
of
process
unit.
Therefore,
all
three
of
the
central
tendencies
were
considered
in
arriving
at
downtime
allowances.
Reasonable
downtime
allowances
appeared
to
be
3
percent
for
rotary/
tube
dryers
(
0.03
x
8,760
=
263
hr/
yr)
and
0.5
percent
for
presses/
veneer
dryers
(
0.005
x
8,760
=
44
hr/
yr).
Biofilters
were
not
included
in
the
analysis
of
1999
downtime.
Biofilters
are
typically
used
to
control
press
emissions.
The
annual
hours
of
downtime
required
for
the
biofilters
in
the
downtime
data
base
generally
match
well
with
the
0.5
percent
downtime
allowance
for
presses/
veneer
dryers.

There
are
process
units
with
control
requirements
in
the
PCWP
NESHAP
other
than
rotary
dryers,
tube
dryers,
presses,
and
veneer
dryers.
The
3
percent
downtime
allowance
was
selected
for
APCDs
controlling
green
rotary
dryers,
tube
dryers,
strand
dryers,
pressurized
refiners,
and
combinations
of
any
of
these
equipment
with
other
process
units.
The
0.5
percent
downtime
allowance
was
selected
for
APCDs
controlling
equipment
that
is
less
susceptible
to
particulate
and
salt
deposition,
including
veneer
dryers,
presses,
board
coolers,
hardboard
ovens,

press
predryers,
and
fiberboard
mat
dryers.
Application
of
the
downtime
allowance
is
per
process
unit
(
i.
e.,
the
downtime
allowance
is
calculated
separately
for
each
process
unit
controlled
using
the
operating
hours
for
each
process
unit).
2­
214
In
a
letter
dated
June
28,
2001,
commenter
IV­
D­
27
specifically
requested
that
an
annual
basis
be
used
for
determining
routine
control
device
downtime
because
"
Oftentimes,
activities
associated
with
routine
maintenance
of
the
RTOs
and
RCOs
(
offline
bakeouts,
washouts,
valve
cleaning,
and
other
activities
to
keep
control
device
pressure
drops
in
acceptable
operating
range)
occur
only
once
per
year.
This
is
particularly
true
for
those
units
with
relatively
light
particulate
loadings
such
as
veneer
dryers
and
presses."
30
We
note
that,
based
on
our
MACT
survey
results
and
Attachment
O
to
comment
IV­
D­
27,

several
routine
maintenance
activities
(
e.
g.,
bakeouts,
washouts)
occur
much
more
frequently
than
once
per
year.
Nevertheless,
we
proposed
to
calculate
the
percentage
of
APCD
downtime
on
an
annual
basis
and
we
maintain
that
using
an
annual
basis
for
calculation
of
the
downtime
allowance
is
appropriate.
We
question
whether
activities
that
occur
less
frequently
than
once
per
year
are
really
"
routine"
maintenance
activities.
To
answer
this
question,
we
reviewed
the
downtime
survey
data
for
the
30
APCDs
used
in
setting
the
downtime
allowance.
We
found
that
12
of
these
30
APCDs
had
downtime
associated
with
media
plugging
or
media
degradation
that
resulted
in
either
partial
or
full
replacement
of
the
media.
Therefore,
we
disagree
with
the
commenters
that
the
media
replacement
was
not
included
in
the
derivation
of
the
downtime
allowance.
In
addition,

we
note
that
the
commenters
are
incorrect
in
stating
that
the
3
percent
downtime
allowance
was
based
on
an
assumption
that
maintenance
is
performed
annually
because
the
data
used
in
determining
the
3
percent
downtime
allowance
included
multiple
events
per
year.
Furthermore,

because
the
same
data
sets
were
used
in
both
the
industry's
79th
percentile
and
our
central
tendencies
analysis,
we
disagree
with
the
commenters
that
basing
the
downtime
allowance
on
the
79th
percentile
instead
of
central
tendencies
would
better
account
for
non­
annual
activities.

Based
on
our
analysis
of
the
downtime
data,
we
maintain
that
the
percentage
downtime
we
proposed
(
3
percent
for
some
units
and
0.5
percent
for
others)
calculated
on
an
annual
basis
is
appropriate
for
the
final
PCWP
rule.
The
downtime
allowance
allowed
under
the
RCDME
is
intended
to
allow
facilities
limited
time
to
perform
routine
maintenance
on
their
APCDs
without
shutting
down
the
process
units
being
controlled
by
the
APCD.
We
included
the
downtime
allowance
in
the
rule
because
we
recognize
that
frequent
maintenance
must
be
performed
to
combat
particulate
and
salt
buildup
in
RTOs
and
RCOs
for
PCWP
drying
processes.
The
downtime
allowance
is
not
intended
to
cover
every
APCD
maintenance
activity,
only
those
maintenance
activities
that
are
routine
(
e.
g.,
bakeouts,
washouts,
partial
or
full
media
2­
215
replacements)
and
do
not
coincide
with
process
unit
shutdowns.
Most
APCD
maintenance
should
occur
during
process
unit
shutdowns;
the
RCDME
is
a
downtime
allowance
in
addition
to
the
APCD
maintenance
downtime
that
occurs
during
process
unit
shutdowns.
We
note
that
most
PCWP
plants
do
not
operate
8,760
hours
per
year
without
shutdowns.
For
example,
the
MACT
survey
responses
indicate
that
softwood
plywood
plants
operate
for
an
average
7,540
hours
per
year,
which
would
allow
1,220
hours
for
control
device
maintenance
without
the
RCDME.
10
Furthermore,
the
RCDME
is
allowed
in
addition
to
APCD
downtime
associated
with
SSM
events
covered
by
the
SSM
plan
(
e.
g.
electrical
problems,
mechanical
problems,
utility
supply
problems,

pre­
filter
upsets).

2.8.1.4
Comment:
Three
commenters
(
IV­
D­
21,
IV­
D­
23,
and
IV­
D­
27)
objected
to
the
requirement
that
the
maintenance
be
scheduled
at
the
beginning
of
the
semiannual
period.

Commenter
IV­
D­
21
stated
that
routine
maintenance
can
easily
be
scheduled
in
advance,
but
equipment
breakdowns
are
never
scheduled,
and
it
is
unreasonable
for
a
facility
to
wait
until
the
beginning
of
the
next
semiannual
period
to
fix
the
equipment.
Also,
facilities
should
have
the
flexibility
to
change
the
control
device
maintenance
schedule
more
than
twice
a
year
so
that
it
corresponds
with
process
maintenance.

Commenter
IV­
D­
23
stated
that
facilities
should
be
able
to
schedule
their
own
maintenance
periods
so
that
they
correspond
with
process
downtime,
as
long
as
the
maintenance
is
performed
on
a
regular
basis.
With
this
change,
facilities
would
not
have
to
worry
that
process
units
are
not
being
appropriately
controlled,
and
they
would
be
able
to
schedule
large­
scale
maintenance,
such
as
bakeouts,
on
holidays
when
the
entire
plant
is
shut
down.

Commenter
IV­
D­
27
stated
that
the
requirement
in
section
63.2251(
e)
to
schedule
maintenance
activities
at
the
beginning
of
each
semiannual
period
is
neither
consistent
with
industry
practice
nor
practical.
It
is
reasonable
to
schedule
maintenance
during
process
downtime,
but
even
process
downtime
is
not
scheduled
on
a
semiannual
basis.
Downtime
for
maintenance
is
scheduled
as
the
need
arises,
and
downtime
schedules
change
with
need
and
production
requirements.
Most
facilities
will
have
a
general
idea
of
when
they
intend
to
conduct
routine
maintenance
activities
and
will
schedule
those
activities
whenever
possible
to
coincide
with
process
downtime
as
it
approaches.
It
is
unclear
under
the
proposed
PCWP
rule
as
to
what
would
happen
if
maintenance
was
necessary
before
the
scheduled
date.
If
facilities
are
forced
to
follow
the
schedule
to
perform
the
maintenance,
then
they
would
likely
be
out
of
compliance
in
2­
216
the
meantime.
In
addition,
facilities
often
perform
maintenance
of
APCDs
in
advance
of
a
scheduled
time
to
take
advantage
of
unexplained
process
outages.
To
eliminate
confusion
and
better
represent
industry
practice,
EPA
should
remove
the
requirement
for
sources
to
schedule
their
control
device
maintenance
schedules
at
the
beginning
of
each
semiannual
compliance
period.

Response:
We
have
revised
§
63.2251(
e)
to
delete
the
requirement
to
record
your
control
device
maintenance
schedule
for
the
semiannual
period.
We
agree
that
this
requirement
would
be
impractical
because
process
unit
shutdowns
are
not
scheduled
semiannually.
Also,
the
SSM
provisions
do
not
require
scheduling
of
maintenance,
and
therefore,
requiring
scheduling
of
routine
maintenance
covered
under
the
RCDME
would
be
more
restrictive
than
the
requirements
for
SSM.
To
the
extent
possible,
APCD
maintenance
should
be
scheduled
at
the
same
time
as
process
unit
shutdowns.
Thus
the
revised
§
63.2251(
e)
retains
the
requirement
that
startup
and
shutdown
of
emission
control
systems
must
be
scheduled
during
times
when
process
equipment
is
also
shut
down.

2.8.1.5
Comment:
Commenter
IV­
D­
27
stated
that
in
addition
to
regular
periodic
maintenance,
the
control
devices
that
form
the
basis
for
the
MACT
floor
are
inappropriate
for
wood
products
sources
and
have
proven
to
be
subject
to
"
catastrophic
failure."
Extended
emission
control
equipment
downtime,
at
times
up
to
several
months,
is
needed
to
replace
major
system
components
when
a
control
device
experiences
a
failure
such
as
rapid
disintegration
of
the
heat
exchange
bed,
rapid
irreversible
plugging
of
the
heat
exchange
bed,
corrosion
and
collapse
of
major
internal
structural
components,
or
an
explosion.
Instead
of
forcing
a
facility
to
shut
down
during
this
time,
the
commenter
requested
that
EPA
minimize
the
substantial
economic
impact
by
stating
in
the
preamble
that
state
enforcement
officials
have
the
discretion
to
recognize
the
industry's
current
inability
to
control
the
occurrence
of
such
events
through
a
variance
or
a
consent
decree
or
similar
enforcement
provision.

Response:
Catastrophic
failures
are
infrequent
and
unique
situations
that
are
best
handled
be
the
applicable
enforcement
authority.
With
any
catastrophic
failure,
the
enforcement
authority
must
participate
in
evaluating
the
cause
of
the
failure
and
the
decision
making
relative
to
whether
the
plant
should
be
allowed
to
continue
operation
under
consent
agreement.
If,
for
example,
the
catastrophic
failure
is
the
result
of
an
accident
or
was
unavoidable,
then
the
enforcement
authority
may
decide
to
handle
the
situation
differently
than
if
the
failure
was
the
result
of
poor
APCD
2­
217
maintenance.
Facilities
generally
have
not
been
forced
to
shut
down
in
those
rare
instances
when
catastrophic
failures
have
occurred
and
enforcement
authorities
have
used
their
discretion
in
these
situations.
We
strongly
disagree
that
it
is
appropriate
for
us
to
conclude
that
all
catastrophic
failures
are
unavoidable,
and
we
further
disagree
that
enforcement
officials
need
to
be
reminded
of
their
discretion
for
handling
such
events.

2.8.1.6
Comment:
Commenter
IV­
D­
27
stated
that
the
statement
in
section
63.2251(
d)

(
What
are
the
requirements
for
the
routine
control
device
maintenance
exemption?)
that
facilities
must
"
minimize
emissions
to
the
greatest
extent
possible"
during
maintenance
periods
is
somewhat
misleading.
Facilities
should
make
reasonable
efforts
to
minimize
emissions
during
control
device
downtime,
but
the
wording
of
the
proposed
rule
could
be
interpreted
to
mean
that
sources
should
limit
production
or
shut
down
entirely
during
maintenance
periods.
That
interpretation
would
negate
any
benefit
to
having
an
equipment
downtime
exemption
and
it
would
not
be
consistent
with
the
MACT
floor.
The
second
sentence
of
section
63.2251(
d)
should
be
either
removed
or
modified
to
require
that
facilities
"
establish
a
maintenance
downtime
program
that
addresses
reasonable
efforts
to
minimize
emissions"
during
routine
control
device
maintenance
periods.

Response:
We
agree
with
the
commenter
that
the
wording
of
§
63.2251(
d)
could
cause
misinterpretation
of
EPA's
intentions.
We
note
that
in
the
proposal,
§
63.2251(
a)
also
required
a
facility
requesting
an
RCDME
to
describe
its
plan
for
minimizing
emissions
to
the
greatest
extent
possible.
To
address
the
commenter's
concern,
we
have
modified
the
second
sentence
of
§
63.2251(
d)
as
suggested,
and
we
have
revised
§
63.2251(
a)
as
follows:

Your
request
must...
describe
how
you
plan
to
minimize
emissions
to
the
greatest
extent
possible
make
reasonable
efforts
to
minimize
emissions
during
the
maintenance...

2.8.1.7
Comment:
Commenter
IV­
D­
27
argued
that
the
difference
between
the
routine
maintenance
downtime
allowance
and
SSM
events
should
be
clearly
defined
in
the
rule.
Section
III.
I
of
the
preamble
states
There
will
also
be
instances
when
a
control
device
is
offline
for
correction
of
malfunctions
such
as
electrical
problems,
mechanical
problems,
utility
supply
problems,
pre­
filter
upsets,
production
malfunctions
(
e.
g.,
dryer
fires),
and
weather­
related
problems.
Because
these
malfunctions
are
sudden,
infrequent,
and
not
reasonably
preventable,
they
would
be
covered
under
the
SSM
provisions
of
today's
proposed
rule.
(
1295)
2­
218
The
commenter
requested
that
this
language,
including
the
examples
of
malfunctions,
be
repeated
in
the
body
of
the
rule.
Specifically,
EPA
should
incorporate
the
SSM
provisions
from
the
MACT
General
Provisions
into
the
rule,
along
with
the
examples
listed
above
of
SSM
events
specific
to
the
wood
products
source
category.

Response:
The
SSM
provisions
from
the
General
Provisions
are
already
incorporated
into
the
PCWP
rule.
Section
63.2250(
c)
and
Table
10
to
subpart
DDDD
both
state
that
§
63.6(
e)(
3)

of
the
General
Provisions
for
writing
SSM
plans
does
apply
to
subpart
DDDD.
We
do
not
believe
that
it
is
necessary
or
appropriate
to
classify
all
of
the
events
in
the
categories
identified
by
the
commenter
as
malfunctions
because
some
occurrences
of
these
events
may
be
reasonably
preventable.
However,
we
do
agree
with
the
commenter
that
further
clarification
is
needed
to
help
facilities
distinguish
between
SSM
events
and
routine
control
device
maintenance.
To
achieve
that
goal,
we
have
provided
examples
of
events
that
would
be
covered
by
the
RCDME
in
§
63.2251(
a)
of
the
final
rule.

2.8.2
Veneer
dryer
burner
relights
2.8.2.1
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
requested
an
exemption
for
situations
where
emissions
from
veneer
dryers
must
bypass
control
devices
to
avoid
damage
to
personnel
or
equipment.
These
situations
include
relighting
the
burner,
opening
the
dryers
to
clear
jams,
and
stopping
the
dryers
to
avoid
fire
or
explosion.
The
commenters
argued
that
provisions
for
these
regular
emission
bypass
events
need
to
be
written
into
the
MACT
performance
standards
to
avoid
unsafe
conditions
and
to
allow
the
facility
to
operate
in
compliance
with
the
MACT
regulations.
Commenter
IV­
D­
21
stated
that
the
bypass
of
control
devices
in
these
situations
existed
when
EPA
was
developing
the
rule,
and
they
were
therefore
incorporated
into
the
MACT
floor.

The
commenters
explained
that
anytime
a
veneer
dryer
is
shut
down
for
any
reason,

scheduled
or
unscheduled,
the
emissions
from
that
dryer
must
be
vented
directly
to
the
atmosphere,
or
purged,
for
three
minutes
to
avoid
a
buildup
of
explosive
gases
before
the
burner
can
be
relit.
The
emissions
cannot
pass
through
an
RTO,
an
RCO,
or
another
dryer
because
these
devices
could
ignite
the
explosive
gas
mixture.
In
addition,
cold
air
must
be
purged
to
avoid
condensation
of
flammable
condensed
organic
material.
Finally,
if
water
or
other
firefighting
chemicals
enter
the
system,
the
air
must
be
purged
before
relight
to
avoid
combustion
of
these
chemicals.
Relighting
the
burner
is
necessary
after
these
frequent
shutdowns
and
when
starting
a
2­
219
dryer
from
cold
shutdown.
Burner
relights
occur
on
average
from
6
to
12
times
per
8­
hour
shift.

Commenter
IV­
D­
27
assumed
that
purging
the
dryers
while
production
is
stopped
in
unscheduled
events
would
be
allowed,
but
noted
that
including
an
exemption
in
the
rule
for
all
relighting
situations
is
important
to
keep
the
plant
safe.

Commenters
IV­
D­
21
and
IV­
D­
27
stated
that
as
the
proposed
rule
stands
now,
bypassing
control
devices
when
a
veneer
dryer
burner
is
relit
is
not
completely
covered.
The
General
Provisions
state
that
a
facility
must
either
comply
with
the
emissions
standard
or
follow
the
SSM
plan,
but
the
proposed
PCWP
rule
is
more
restrictive.
The
exemption
provided
in
the
rule
only
covers
scheduled
startups,
such
as
weekly
startups
after
routine
maintenance,
not
relights
after
temporary
shutdowns.
Also,
the
SSM
plan
does
not
include
an
exemption
from
the
emission
requirements.
The
language
of
the
proposed
rule
about
minimizing
emissions
to
the
greatest
extent
possible
during
unscheduled
shutdowns
could
be
interpreted
to
mean
that
purging
is
not
acceptable,
even
if
it
is
necessary
to
avoid
fire.
The
commenters
argued
that
the
language
of
the
PCWP
rule
could
be
changed
to
reflect
the
General
Provisions
wording,
and
purging
could
be
included
in
the
SSM
plan
to
maintain
safety.
The
commenters
also
pointed
out
that
minimizing
the
emissions
to
the
level
of
PBCO
limits
does
not
qualify
as
`
minimizing
emissions
to
the
levels
required
by
the
relevant
standards'
because
the
proposed
language
prohibits
using
multiple
compliance
options
for
a
single
process
unit.
Commenter
IV­
D­
27
added
that
emissions
during
burner
startup
may
or
may
not
be
lower
than
emissions
when
the
dryers
are
operating
at
the
maximum
capacity.
The
emissions
are
expected
to
be
lower
the
longer
the
burners
are
off
because
the
dryer
will
cool
when
not
heated.

As
a
result
of
this
situation,
commenters
IV­
D­
21
and
IV­
D­
27
suggested
revisions
to
the
proposed
rule.
First,
SSM
events
should
not
be
labeled
as
"
deviations"
since
the
General
Provisions
do
not
define
them
that
way.
See
comment
No.
2.8.4.1
under
Deviations
for
more
details.
Startups
of
the
gas­
fired
burners
in
direct­
fired
veneer
dryers
should
not
be
classified
as
deviations
either.
If
these
events
need
to
be
reported,
then
EPA
should
define
a
different
category
for
reporting
them.
Second,
the
word
"
scheduled"
should
be
removed
from
section
63.2250(
d)

(
What
are
the
requirements
for
periods
of
startup,
shutdown,
and
malfunction?).
See
comment
No.
2.8.3.5
under
SSM
Plan
for
more
information.
Alternatively,
if
making
that
change
is
determined
to
be
too
broad,
EPA
could
specifically
develop
an
exemption
for
periods
when
2­
220
direct­
fired
burners
are
shut
off
and/
or
are
being
relit
by
adding
wording
to
the
regulation
that
reads
The
compliance
options,
operating
requirements,
and
work
practice
requirements
in
§
63.2240
do
not
apply
during
times
when
process
gases
from
direct­
fired
processes
are
vented
to
atmosphere
for
safety
purposes
during
periods
when
process
burners
are
shut
off
or
during
start
or
re­
start
of
process
heaters.

This
revision
specifically
does
not
include
the
phrase
"
you
must
minimize
emissions
to
the
greatest
extent
possible"
because
such
a
phrase
could
be
interpreted
to
require
that
dryers
be
cooled
before
restart
to
reduce
emissions
during
purging.
All
of
the
direct­
fired
veneer
dryers
in
EPA's
database
that
had
thermal
and
catalytic
emission
control
equipment
practiced
bypass
of
emissions
during
burner
shutdown
and
restart,
so
these
practices
are
part
of
the
floor.
Finally,
the
PCWP
rule
should
specifically
address
direct­
fired
veneer
dryer
starts,
restarts,
and
partial
restarts.
The
frequent
nature
of
dryer
relights
should
be
considered
separately
from
the
infrequent
occurrence
of
SSM
events,
and
language
should
be
added
to
section
63.2250(
e)
to
specifically
address
and
regulate
this
process.
Suggested
wording
is:

(
e)
Shut­
off
of
direct­
fired
burners
resulting
from
partial
and
full
production
stoppages
of
direct­
fired
veneer
dryers
or
over­
temperature
events
shall
be
deemed
shutdowns
and
not
malfunctions.
Lighting,
or
re­
lighting
any
one
or
all
gas
burners
in
direct­
fired
veneer
dryers
shall
be
deemed
start­
ups
and
not
malfunctions.

Commenter
IV­
D­
27
stated
that
these
changes
are
needed
to
prevent
endless
negotiation
with
states
and
nongovernmental
organizations
(
NGOs)
about
this
issue.
If
the
frequent
line
stoppages
at
veneer
dryers
were
to
be
interpreted
as
malfunctions,
additional
rules
would
apply
regarding
the
frequency
of
such
events.
A
malfunction
would
have
to
fit
the
malfunction
definition
given
by
the
General
Provisions,
and
the
line
stoppages
discussed
in
this
section
do
not
meet
the
"
infrequent"
term
in
the
definition.
Also,
bypassing
a
control
device
could
be
challenged
by
administrator
or
public
advocacy
groups
through
citizen
suit
provisions,
and
according
to
section
63.6(
e)(
3)(
vii)
of
the
General
Provisions,
EPA
has
the
power
to
require
modification
of
the
SSM
plan.
To
completely
avoid
this
situation,
the
commenter
argued
that
the
rule
must
contain
explicit
language
that
allows
control
equipment
bypass
during
these
specific
events,
defines
them
as
startups
and
shutdowns,
and
does
not
define
them
as
deviations.
2­
221
Response:
We
agree
with
the
commenters
that
safety
issues
should
be
considered
when
attempting
to
minimize
emissions.
Recent
amendments
to
§
63.6(
e)(
1)(
i)
of
the
General
Provisions
have
added
safety
considerations
to
the
explanation
of
the
general
duty
to
minimize
emissions.
The
version
of
the
General
Provisions
that
was
available
to
the
commenters
when
their
comments
were
written
(
the
amendments
to
the
General
Provisions
promulgated
on
April
5,
2002
(
67
FR
16605)),
state
that
"
At
all
times,
including
periods
of
startup,
shutdown,
and
malfunction,
the
owner
or
operator
must
operate
and
maintain
any
affected
source,
including
associated
air
pollution
control
equipment
and
monitoring
equipment,
in
a
manner
consistent
with
safety
and
good
air
pollution
control
practices
for
minimizing
emissions
to
the
levels
required
by
the
relevant
standards,
i.
e.,
meet
the
emission
standard
or
comply
with
the
startup,
shutdown,
and
malfunction
plan."
[
emphasis
added]

The
newest
version,
promulgated
May
30,
2003
(
68
FR
32586),
states
"
At
all
times,
including
periods
of
startup,
shutdown,
and
malfunction,
the
owner
or
operator
must
operate
and
maintain
any
affected
source,
including
associated
air
pollution
control
equipment
and
monitoring
equipment,
in
a
manner
consistent
with
safety
and
good
air
pollution
control
practices
for
minimizing
emissions.
During
a
period
of
startup,
shutdown,
or
malfunction,
this
general
duty
to
minimize
emissions
requires
that
the
owner
or
operator
reduce
emissions
from
the
affected
source
to
the
greatest
extent
which
is
consistent
with
safety
and
good
air
pollution
control
practices.
The
general
duty
to
minimize
emissions
during
a
period
of
startup,
shutdown,
or
malfunction
does
not
require
the
owner
or
operator
to
achieve
emission
levels
that
would
be
required
by
the
applicable
standard
at
other
times
if
this
is
not
consistent
with
safety
and
good
air
pollution
control
practices,
nor
does
it
require
the
owner
or
operator
to
make
any
further
efforts
to
reduce
emissions
if
levels
required
by
the
applicable
standard
have
been
achieved."
[
emphasis
added]

The
statement
"
meet
the
emission
standard
or
comply
with
the
startup,
shutdown,
and
malfunction
plan"
is
no
longer
a
part
of
the
general
duty
to
minimize
emissions
in
the
General
Provisions.
In
order
to
be
consistent
with
the
General
Provisions,
we
have
deleted
the
requirement
that
emissions
must
be
minimized
to
the
greatest
extent
possible
in
§
63.2250(
d).
A
reference
to
§
63.6(
e)(
1)(
i)
of
the
General
Provisions
was
already
included
in
the
proposed
PCWP
rule
in
§
63.2250(
b).
Since
purging
of
veneer
dryers
for
burner
relights
is
a
safety
issue,
this
change
should
help
to
alleviate
the
commenters'
concern.
Due
to
the
frequent
nature
of
veneer
dryer
burner
relights,
we
agree
that
these
events
cannot
be
termed
"
malfunctions."
Therefore,
we
have
included
language
similar
to
the
wording
suggested
for
paragraph
63.2250(
d)
by
the
2­
222
commenter
to
further
clarify
this
issue.
See
the
response
to
Comment
No.
2.8.4.1
for
our
position
on
deviations
and
the
response
to
Comment
No.
2.8.3.5
for
our
position
on
removing
"
scheduled"

from
§
63.2250(
d).

2.8.3
SSM
plan
2.8.3.1
Comment:
Commenter
IV­
D­
26
argued
that
the
CAA
requires
EPA
to
set
emission
control
standards
on
a
continuous
basis,
and
allowing
SSM
conditions
to
be
exempt
from
these
controls
is
an
unlawful
loophole.
Compliance
with
the
SSM
plan
does
not
make
the
condition
lawful,
since
the
SSM
plans
are
generated
by
the
facilities
themselves.
In
addition,

Commenter
IV­
D­
26
stated
that
EPA's
compliance
provision
is
unlawful
because
it
conflicts
with
§
304,
which
expressly
allows
citizens
to
enforce
emission
limitations.
Under
EPA's
regulations,
a
source
would
be
deemed
in
compliance,
in
spite
of
a
deviation
from
the
emission
standards,
if
it
demonstrates
to
the
Administrator's
satisfaction
it
was
operating
in
compliance
with
its
SSM
plan
during
periods
of
SSM.
The
proposed
regulations
do
not
indicate
how
this
provision
would
operate
in
enforcement
suits
brought
by
citizens
rather
than
the
Administrator.

Response:
We
disagree
with
the
commenter
that
compliance
with
emission
limits
must
be
maintained
during
periods
of
SSM.
The
NESHAP
General
Provisions
provide
some
relief
from
emission
standards
during
SSM
conditions,
but
sources
do
not
necessarily
receive
a
blanket
exemption
from
those
emission
limitations
during
all
SSM
conditions.
Specifically,
§
63.6(
f)(
1)
of
the
NESHAP
General
Provisions
states
that
"
The
non­
opacity
emission
standards
set
forth
in
this
part
shall
apply
at
all
times
except
during
periods
of
startup,
shutdown,
and
malfunction,
and
as
otherwise
specified
in
an
applicable
subpart.
If
a
startup,
shutdown,
or
malfunction
of
one
portion
of
an
affected
source
does
not
affect
the
ability
of
particular
emission
points
within
other
portions
of
the
affected
source
to
comply
with
the
nonopacity
emission
standards
set
forth
in
this
part,
then
that
emission
point
must
still
be
required
to
comply
with
the
nonopacity
emission
standards
and
other
applicable
requirements."

Sections
63.6(
e)
and
63.7(
e)(
1)
provide
similar
wording,
and
all
three
of
the
referenced
sections
are
listed
in
Table
10
to
subpart
DDDD
as
being
applicable
to
subpart
DDDD.
During
periods
of
SSM,
the
facility
must
operate
according
to
an
SSM
plan
that
satisfies
the
requirements
of
§
63.6(
e)(
3).
We
also
acknowledge
the
commenter's
concern
about
a
facility
complying
with
an
SSM
plan
that
was
developed
by
that
facility.
To
address
this
very
concern,
we
promulgated
amendments
to
the
NESHAP
General
Provisions
(
68
FR
32586,
May
30,
2003).
Under
the
2­
223
promulgated
amendments,
§
63.6(
e)(
3)(
v)
requires
owners
or
operators
of
affected
sources
subject
to
a
part
63
standard
to
submit
a
copy
of
the
SSM
plan
to
the
Administrator
upon
receiving
a
written
request
from
the
Administrator.
Any
time
a
member
of
the
public
submits
a
"
specific
and
reasonable
request"
to
view
the
SSM
plan
of
an
affected
source,
the
Administrator
has
an
obligation
to
submit
that
request
to
the
affected
source.
In
addition,
§
63.6(
e)(
1)(
i)
allows
the
Administrator
to
make
a
determination
of
the
adequacy
of
the
SSM
plan,
and
§
63.6(
e)(
3)(
vii)

requires
an
affected
source
to
make
changes
to
the
SSM
plan
if
it
is
determined
to
be
unacceptable.
The
language
in
section
63.6(
e)(
1)(
i)
also
makes
it
clear
that
during
a
period
of
SSM,
the
general
duty
to
minimize
emissions
requires
the
owner
or
operator
to
reduce
emissions
to
the
greatest
extent
consistent
with
safety
and
good
air
pollution
control
practices.
However,

during
an
SSM
event,
the
general
duty
to
minimize
emissions
does
not
require
the
owner
or
operator
to
achieve
levels
required
by
the
MACT
standard
during
non­
SSM
periods.
As
stated
in
the
preamble
to
the
final
rule
(
General
Provisions),
we
believe
we
have
discretion
to
make
reasonable
distinctions
concerning
those
particular
activities
to
which
the
emission
limitations
of
a
MACT
standard
apply,
and
note
that
exceedances
of
generally
applicable
emissions
limitations
will
be
limited
to
those
instances
where
they
cannot
be
reasonably
avoided.
(
See
38
FR
32589­

3593,
May
30,
2003.)
We
believe
these
amendments
address
the
commenter's
concerns.
In
addition,
the
criteria
for
writing
and
using
SSM
plans
are
covered
in
the
NESHAP
General
Provisions.

We
believe
that
our
statutory
standard­
setting
obligations
do
not
preclude
the
establishment
of
appropriate
regulatory
mechanisms
to
deal
generally
with
issues
such
as
SSM.

Therefore,
enforcement
actions
during
periods
of
SSM
depend
not
on
whether
the
facility
is
meeting
the
otherwise
applicable
emission
standards,
but
whether
the
facility
is
operating
in
accordance
with
an
adequate
SSM
plan.
To
the
extent
that
anyone
can
pursue
enforcement
actions
for
violations
during
periods
of
SSM,
such
violations
will
consist
of
failure
to
comply
with
the
applicable
SSM
plan
(
as
required
by
§
63.6(
e)(
3)(
ii))
or
substantive
inadequacies
in
the
SSM
plan
itself
that
amount
to
violations
of
the
§
63.6(
e)(
3)
plan
requirements.
In
circumstances
where
such
violations
occur,
citizens
may
pursue
enforcement
action
under
§
304
of
the
CAA,
just
as
they
may
pursue
enforcement
actions
when
a
facility
violates
an
emission
standard
or
any
other
NESHAP
requirement
during
normal
plant
operation.
However,
for
violations
during
SSM,
such
a
suit
would
focus
on
whether
the
facility
was
operating
according
to
its
SSM
plan
and/
or
2­
224
whether
the
SSM
plan
itself
was
adequate
according
to
the
requirements
of
§
63.6(
e)(
3).
Thus,

there
is
no
inconsistency
between
EPA's
SSM
requirements
and
the
statute's
provisions
regarding
citizen's
rights
to
enforce
EPA's
regulations.

2.8.3.2
Comment:
Commenter
IV­
D­
21
pointed
out
that
some
of
the
sections
of
the
proposal
that
deal
with
SSM
do
not
specify
whether
the
SSM
applies
to
the
control
device,
the
process,
or
both.
For
example,
section
63.2250(
a)
seems
to
indicate
control
device
SSM,
while
section
63.2250(
d)
seems
to
indicate
process
SSM.
Adding
the
phrase
"
control
device"
before
both
occurrences
of
the
word
"
startup"
in
section
63.2250(
a)
would
help
to
clarify
that
point.
If
SSM
applicability
was
narrowed
to
the
control
device
only,
then
the
burden
would
be
less
on
both
the
reporting
and
reviewing
parties.
Also,
section
63.2281(
c)(
4)
of
the
proposal
seems
to
require
that
every
single
SSM
event
be
documented
in
the
records,
even
the
numerous
minor
occasions
that
would
not
affect
the
abilities
of
the
control
devices.
If
the
reports
were
full
of
these
minor
situations,
the
major
SSM
events
would
tend
to
receive
less
notice.
EPA
should
incorporate
the
comments
of
The
Coalition
for
Clean
Air
Implementation
on
the
"
National
Emission
Standards
for
Hazardous
Air
Pollutants
for
Source
Categories:
General
Provisions"
regarding
SSM
events
that
do
not
affect
the
control
systems
into
this
rule.

Response:
We
agree
with
the
commenter
that
the
explanation
of
periods
when
the
compliance
options,
operating
requirements,
and
work
practice
requirements
do
and
do
not
apply
is
confusing.
Our
intention
is
for
the
SSM
periods
mentioned
in
§
63.2250(
a)
to
apply
to
both
process
units
and
control
devices.
The
circumstances
listed
in
§
63.2250(
d)
are
periods
in
addition
to
those
listed
in
§
63.2250(
a)
during
which
the
compliance
options,
operating
requirements,
and
work
practice
requirements
do
not
apply.
Since
SSM
plans
address
all
startups
and
shutdowns,

we
wanted
to
specify
that
the
amount
of
time
taken
for
scheduled
startups
and
shutdowns
should
be
minimized.
That
statement
does
not
mean
that
unscheduled
startups
and
shutdowns
are
automatically
subject
to
the
compliance
options,
operating
requirements,
and
work
practice
requirements;
unscheduled
startups
and
shutdowns
should
be
covered
to
the
greatest
extent
possible
in
the
SSM
plan.
To
clarify
the
SSM
guidelines,
we
have
combined
§
63.2250(
d)
with
§
63.2250(
a)
and
revised
the
resulting
§
63.2250(
a).

To
address
the
commenter's
concern
that
§
63.2281(
c)(
4)
would
require
all
SSM
events
to
be
documented,
we
point
out
that
§
63.2281(
c)(
4)
states
the
following:
2­
225
"
If
you
had
a
startup,
shutdown,
or
malfunction
during
the
reporting
period
and
you
took
actions
consistent
with
your
SSMP,
the
compliance
report
must
include
the
information
specified
in
§
63.10(
d)(
5)(
i)."

At
the
time
that
the
commenter
wrote
this
comment,
§
63.10(
d)(
5)(
i)
of
the
General
Provisions
did
require
that
"
the
number,
duration,
and
a
brief
description
of
each
startup,
shutdown,
or
malfunction"
be
included
in
the
report
(
67
FR
16605,
April
5,
2002).
Since
then,
the
General
Provisions
have
been
revised,
and
that
reporting
burden
has
been
reduced.
According
to
the
preamble
of
the
amendments
to
the
General
Provisions
promulgated
on
May
30,
2003
"
In
some
industries,
startup
and
shutdown
events
are
numerous
and
routine.
So
long
as
the
provisions
of
the
SSM
plan
are
followed,
there
does
not
appear
to
be
any
real
utility
in
requiring
that
each
individual
startup
and
shutdown
be
reported
or
described...
[
I]
n
those
instances
where
a
startup
or
shutdown
includes
actions
which
do
not
conform
to
the
SSM
plan
and
the
standard
is
exceeded,
the
facility
is
otherwise
required
to
promptly
report
these
deviations
from
the
plan...
[
R]
eporting
of
malfunctions
would
help
permitting
authorities
determine
whether
sources
are
attempting
to
circumvent
the
standard
by
improperly
defining
events
as
malfunctions.
To
prevent
this
type
of
potential
abuse,
we
do
not
think
that
all
malfunctions
need
to
be
reported.
Rather,
we
think
this
problem
can
be
addressed
by
requiring
that
the
affected
source
report
only
those
malfunctions
which
occurred
during
the
reporting
period
and
which
caused
or
may
have
caused
an
emission
limitation
in
the
relevant
standard
to
be
exceeded.
Thus,
we
have
decided
to
retain
the
requirement
that
the
owner
or
operator
report
malfunctions
in
the
periodic
report,
but
to
limit
its
scope
to
those
malfunctions
which
caused
or
may
have
caused
an
emission
limitation
in
the
relevant
standard
to
be
exceeded."
(
68
FR
32592)
[
emphasis
added]

As
a
result,
§
63.10(
d)(
5)(
i)
of
the
General
Provisions
now
lists
the
following
requirements
for
the
periodic
startup,
shutdown,
and
malfunction
reports:

"
If
actions
taken
by
an
owner
or
operator
during
a
startup,
shutdown,
or
malfunction
of
an
affected
source
(
including
actions
taken
to
correct
a
malfunction)
are
consistent
with
the
procedures
specified
in
the
source's
startup,
shutdown,
and
malfunction
plan
(
see
§
63.6(
e)(
3)),
the
owner
or
operator
shall
state
such
information
in
a
startup,
shutdown,
and
malfunction
report.
Such
a
report
shall
identify
any
instance
where
any
action
taken
by
an
owner
or
operator
during
a
startup,
shutdown,
or
malfunction
(
including
actions
taken
to
correct
a
malfunction)
is
not
consistent
with
the
affected
source's
startup,
shutdown,
and
malfunction
plan,
but
the
source
does
not
exceed
any
applicable
emission
limitation
in
the
relevant
emission
standard.
Such
a
report
shall
also
include
the
number,
duration,
and
a
brief
description
for
each
type
of
malfunction
which
occurred
during
the
reporting
period
and
which
caused
or
may
have
caused
any
applicable
emission
limitation
to
be
exceeded."
(
68
FR
32601)

The
revised
reporting
requirements
should
help
to
minimize
the
commenter's
concern.
2­
226
2.8.3.3
Comment:
Commenter
IV­
D­
27
supported
the
exemptions
from
compliance
options,
operating
requirements,
and
work
practice
requirements
during
periods
of
SSM
and
made
a
suggestion
to
clarify
the
requirements.
The
EPA
should
use
emission
standards
rather
than
operating
limits
for
determining
if
an
interruption
in
production
is
a
malfunction
or
not.

Wood
products
facilities
experience
many
sudden
stops,
starts,
or
other
minor
malfunctions
during
the
course
of
a
work
day
that
do
not
affect
the
operation
of
the
control
device.
Reporting
each
one
of
these
interruptions
detracts
from
the
purpose
and
clarity
of
reporting.
The
EPA
explains
its
interpretation
of
the
malfunction
definition
at
67
FR
72881:

We
recognize
that
some
sources
are
concerned
that
the
requirement
to
periodically
report
malfunctions
may
be
interpreted
to
require
reporting
of
minor
problems
that
have
no
impact
on
emissions.
However,
we
do
not
construe
the
provision
in
this
manner.
Under
our
regulations,
`
malfunction'
is
defined
as
`
any
sudden,
infrequent,
and
not
reasonably
preventable
failure
of
air
pollution
control
and
monitoring
equipment,
process
equipment,
or
a
process
to
operate
in
a
normal
or
usual
manner.'
See
40
C.
F.
R.
63.2.
Only
those
events
that
meet
this
definition
would
be
subject
to
the
reporting
requirement.
During
an
event
that
meets
this
definition,
the
facility
is
not
required
to
comply
with
otherwise
applicable
emission
limits,
and
the
SSM
plan
must
specify
alternative
procedures
which
satisfy
the
general
duty
to
minimize
emissions.
Minor
or
routine
events
that
have
no
appreciable
impact
on
the
ability
of
a
source
to
meet
the
standard
need
not
be
classified
by
the
source
as
a
malfunction,
addressed
in
the
SSM
plan,
or
included
in
periodic
reports.
Thus,
if
a
source
experiences
a
minor
problem
that
does
not
affect
its
ability
to
meet
the
applicable
emission
standard,
the
problem
need
not
be
addressed
by
the
SSM
plan
and
would
not
be
a
reportable
`
malfunction'
under
our
regulations.

The
commenter
agreed
with
this
interpretation
and
suggested
that
in
order
to
evaluate
the
effect
of
the
equipment
on
emissions,
the
definition
of
malfunction
should
be
revised
as
follows
(
addition
in
italics):

Any
sudden,
infrequent,
and
not
reasonably
preventable
failure
of
air
pollution
control
and
monitoring
equipment,
process
equipment,
or
a
process
to
operate
in
a
normal
or
usual
manner
affecting
the
ability
of
the
affected
source
to
meet
a
relevant
standard
or
of
monitoring
equipment
to
operate
in
a
normal
or
usual
manner.

This
revision
does
not
mean
a
source
needs
to
have
absolute
knowledge
that
it
exceeded
emission
levels
to
include
a
failure
in
a
malfunction
report.
A
source
is
permitted
to
report
all
such
events
if
it
chooses.
The
revision
simply
clarifies
that
if
a
source
knows
that
its
ability
to
comply
was
not
affected,
the
event
need
not
be
reported
as
a
malfunction.
2­
227
Response:
The
definition
of
"
malfunction"
is
included
in
the
NESHAP
General
Provisions
(
40
CFR
63,
subpart
A),
not
the
PCWP
NESHAP.
The
NESHAP
General
Provisions,
including
the
definition
of
"
malfunction,"
were
recently
revised
and
updated.
Amendments
to
the
NESHAP
General
Provisions
concerning
SSM
procedures
were
proposed
in
67
FR
72875
(
December
9,

2002)
and
promulgated
in
68
FR
32585
(
May
30,
2003).
The
EPA
noted
in
the
preamble
to
the
final
amendments
to
the
NESHAP
General
Provisions
that
"
A
number
of
commenters
requested
that
we
make
this
policy
clear
in
the
regulatory
language,
rather
than
only
in
the
preamble.
These
commenters
suggested
that
the
definition
of
malfunction
could
be
revised
to
accomplish
this.
We
think
this
is
a
good
idea,
and
we
have
revised
the
definition
accordingly.
We
think
that
this
change
will
make
it
clear
that
events
that
do
not
cause,
or
have
the
potential
to
cause,
emission
limitations
in
an
applicable
standard
to
be
exceeded
need
not
be
included
either
in
the
SSM
plan
or
in
periodic
malfunction
reports.
(
68
FR
32592­
3,
May
30,
2003)
As
a
result,
the
first
sentence
of
the
most
recent
definition
of
"
malfunction"
reads
as
follows:

"
Malfunction
means
any
sudden,
infrequent,
and
not
reasonably
preventable
failure
of
air
pollution
control
and
monitoring
equipment,
process
equipment,
or
a
process
to
operate
in
a
normal
or
usual
manner
which
causes,
or
has
the
potential
to
cause,
the
emission
limitations
in
an
applicable
standard
to
be
exceeded."
(
68
FR
32600,
May
30,
2003)

Although
the
amendments
to
the
NESHAP
General
Provisions
regarding
SSM
plans
are
currently
involved
in
litigation,
the
definition
of
"
malfunction"
promulgated
on
May
30,
2003,
applies
to
the
PCWP
NESHAP
unless
EPA
promulgates
another
revision.
Therefore,
we
disagree
that
it
is
necessary
or
appropriate
to
make
any
further
changes
to
the
definition
as
suggested
by
the
commenter
or
to
include
a
separate
definition
of
"
malfunction"
in
the
PCWP
NESHAP.

2.8.3.4
Comment:
Commenter
IV­
D­
27
noted
that
the
reference
to
the
General
Provisions
in
section
63.2250(
b)
is
redundant.
In
addition,
the
General
Provisions
are
under
revision,
so
deleting
the
entire
section
would
eliminate
any
potential
conflicts
with
the
revised
general
provisions.

Response:
Section
63.2250(
b)
refers
to
§
63.6(
e)(
1)
of
the
General
Provisions,
which
addresses
the
general
duty
to
minimize
emissions
during
SSM
events.
This
section
of
the
General
Provisions
was
updated
by
an
amendment
promulgated
on
May
30,
2003
(
68
FR
32585),
and
this
revised
version
of
§
63.6(
e)(
1)
of
the
General
Provisions
does
apply
to
the
PCWP
NESHAP.
We
note
that
we
cannot
adequately
address
the
commenter's
concern
about
redundancy
because
the
commenter
did
not
clarify
which
section
or
reference
is
redundant
with
the
reference
to
the
General
Provisions
in
§
63.2250(
b).
2­
228
2.8.3.5
Comment:
Commenter
IV­
D­
27
requested
that
the
word
"
scheduled"
be
removed
from
section
63.2250(
d)
(
What
are
the
requirements
for
periods
of
startup,
shutdown,
and
malfunction?).
Currently,
the
proposed
PCWP
rule
only
exempts
scheduled
startup
and
shutdown
events,
and
some
unscheduled
startups
and
shutdowns
are
considered
malfunctions,
which
are
also
exempt.
However,
many
unscheduled
process
startups
and
shutdowns
cannot
be
considered
malfunctions
because
of
their
frequency.
During
these
periods,
facilities
may
find
themselves
in
violation
of
compliance
caused
by
little
to
no
flow
of
HAP
to
the
control
device
inlet,
not
by
an
inadequate
control
device.
Deleting
"
scheduled"
from
the
rule
would
help
facilities
avoid
that
situation.

Commenter
IV­
D­
21
stated
that
section
63.2250(
d)
should
be
changed
to
clarify
that
the
SSM
events
apply
to
process
SSM
and
not
the
control
devices.
Also,
it
is
unnecessary
to
specify
that
only
scheduled
startup
and
shutdown
periods
are
exempt,
since
some
unscheduled
startups
and
shutdowns
could
be
considered
malfunctions,
which
are
exempt
as
well.
The
events
that
cannot
be
classified
as
malfunctions
are
generally
the
minor
shutdowns
and
startups
that
do
not
affect
the
control
device.
Unless
unscheduled
startups
and
shutdowns
are
included
in
the
exemption,
many
facilities
are
likely
to
be
out
of
compliance
with
the
rule
for
short
periods
of
time
every
day.

Response:
As
explained
in
the
response
to
Comment
No.
2.8.3.2,
both
§
63.2250(
a)
and
§
63.2250(
d)
apply
to
process
units
and
control
devices.
The
circumstances
listed
in
§
63.2250(
d)

are
periods
in
addition
to
those
listed
in
§
63.2250(
a)
during
which
the
compliance
options,

operating
requirements,
and
work
practice
requirements
do
not
apply.
Since
SSM
plans
address
all
startups
and
shutdowns,
we
wanted
to
specify
that
the
amount
of
time
taken
for
scheduled
startups
and
shutdowns
should
be
minimized.
That
statement
does
not
mean
that
unscheduled
startups
and
shutdowns
are
automatically
subject
to
the
compliance
options,
operating
requirements,
and
work
practice
requirements;
unscheduled
startups
and
shutdowns
should
be
covered
to
the
greatest
extent
possible
in
the
SSM
plan.
To
minimize
confusion,
§
§
63.2250(
a)

and
63.2250(
d)
have
been
combined
and
revised.

2.8.3.6
Comment:
Commenters
IV­
D­
21
and
IV­
D­
27
noted
that
sections
63.2250(
e)

and
63.2251(
e)
are
exactly
the
same,
and
one
of
them
should
be
removed
to
avoid
unnecessary
duplication.
2­
229
Response:
After
reviewing
the
rule,
we
agree
with
the
commenter
that
§
63.2250(
e)
is
unnecessary
duplication
of
§
63.2251(
e),
and
we
have
removed
§
63.2250(
e)
from
the
rule.
See
the
response
to
Comment
No.
2.8.1.4
for
our
position
on
recording
the
control
device
maintenance
schedule
at
the
beginning
of
each
semiannual
compliance
period
to
receive
the
routine
control
device
maintenance
exemption.

2.8.3.7
Comment:
Commenter
IV­
D­
27
stated
that
section
63.2250(
f)
should
be
removed
from
the
rule,
mainly
because
EPA
does
not
clarify
what
this
section
has
to
do
with
SSM.
The
requirement
to
operate
and
maintain
RCO
catalysts
according
to
manufacturers'

specifications
limits
a
facility's
ability
to
react
and
respond
to
changing
conditions.
If
a
mill
is
to
be
held
ultimately
responsible
for
compliance
to
the
standard,
it
should
be
given
all
reasonable
opportunities
to
meet
the
requirements,
including
flexibility
in
operating
and
maintaining
an
RCO.

Some
facilities
may
have
situations
in
which
they
use
catalysts
from
different
manufacturers
or
the
catalyst
or
RCO
vendor
has
gone
out
of
business.
These
factors
could
make
it
difficult
to
comply
with
this
requirement.
Because
of
the
high
costs
of
the
equipment
and
compliance
violations,

properly
maintaining
the
equipment
is
in
the
facility's
best
interest.
For
all
of
these
reasons,

section
63.2250(
f)
should
be
removed
from
the
PCWP
rule.

Response:
We
have
eliminated
the
requirement
for
facilities
to
maintain
the
catalyst
according
to
manufacturers'
specifications
and
the
proposed
§
63.2250(
f)
from
the
rule.
As
discussed
in
response
to
Comment
No.
2.7.11.6,
we
have
replaced
this
requirement
with
a
requirement
to
perform
an
annual
check
of
catalyst
activity.

2.8.4
Deviations
2.8.4.1
Comment:
Commenter
IV­
D­
27
suggested
that
section
63.2271(
b)
be
revised
to
clearly
state
that
SSM
events
are
not
considered
deviations.
EPA
should
clarify
that
SSM
events
are
to
be
reported
as
deviations
only
when
there
is
a
deviation
from
the
compliance
options,

operating
requirements,
and
work
practice
standards.
Also,
the
reference
to
63.6(
e)
should
be
deleted
because
it
conflicts
with
this
provision.
The
commenter
argued
that
not
all
deviations
result
in
violation
of
compliance,
and
recording
all
of
these
situations
makes
it
harder
to
find
the
situations
that
were
truly
violations.
The
recommended
revisions
to
63.2271(
b)
are
as
follows
(
added
text
in
italics):

[
T]
his
includes
periods
of
startup,
shutdown,
or
malfunction
and
periods
of
control
device
maintenance
specified
in
paragraphs
(
b)(
1)
and
(
3)
of
this
section
except
for
when
2­
230
emission
control
equipment
is
being
started
up
or
shut
down,
when
the
production
process
generating
the
emissions
to
be
controlled
is
not
operating,
or
when
the
production
process
generating
the
emissions
is
started
or
shut
down
when
the
emission
control
equipment
is
meeting
its
operating
requirements 

Commenter
IV­
D­
27
requested
that
the
final
rule
not
identify
SSM
events
as
deviations.
The
commenter
stated
that
in
the
proposed
definition
of
deviation,
all
startups
and
shutdowns
of
emission
control
equipment
would
be
considered
deviations
because
it
would
not
be
possible
to
either
start
up
or
shut
down
a
control
device
without
being
outside
one
of
the
operating
requirements.
As
an
example,
the
commenter
pointed
out
that
starting
up
an
RTO
or
RCO
usually
requires
that
the
temperature
be
raised
to
the
proper
operating
range,
and
during
this
warm­
up
period,
the
temperature
will
not
meet
the
minimum
operating
temperature
requirement,

nor
will
the
pressure
at
the
inlet
be
within
the
proper
range.
The
commenter
also
noted
that
under
normal
conditions,
the
emission
control
devices
are
not
receiving
emissions
when
they
are
starting
up
or
shutting
down.
Because
the
emissions
do
not
start
flowing
to
the
control
device
until
it
is
ready,
startups
and
shut
downs
should
not
be
defined
as
deviations.
To
address
this
issue,
the
commenter
recommends
that
item
(
3)
of
the
proposed
definition
of
deviation
be
deleted
as
follows
(
additions
are
in
italics
and
deletions
are
in
strikeout
format):

Deviation
means
any
instance
in
which
an
affected
source
subject
to
this
subpart,
or
an
owner
or
operator
of
such
a
source:
(
1)
Fails
to
meet
any
requirement
or
obligation
established
by
this
subpart
including,
but
not
limited
to,
any
at
least
one
compliance
option,
operating
requirement,
or
work
practice
requirement
while
the
process
is
operating;
or
(
2)
Fails
to
meet
any
term
or
condition
that
is
adopted
to
implement
an
applicable
requirement
in
this
subpart,
and
that
is
included
in
the
operating
permit
for
any
affected
source
required
to
obtain
such
a
permit;
or
(
3)
Fails
to
meet
any
compliance
option,
operating
requirement,
or
work
practice
requirement
in
this
subpart
during
startup,
shutdown,
or
malfunction,
regardless
or
whether
or
not
such
failure
is
permitted
by
this
subpart.

Also,
a
special
exemption
should
be
allowed
for
biofilter
initial
startup.
EPA
should
require
that
emissions
be
introduced
to
biofilters
during
initial
start­
up.

The
commenter
also
recommended
that
a
definition
of
"
instance"
be
added
to
the
final
rule
to
clarify
the
meaning
of
this
term
as
it
is
used
in
the
definition
of
deviation,
as
follows:

Instance
means
any
compliance
block
average,
operating
requirement
block
average,
or
work
practice
block
average.
2­
231
Response:
The
term
"
deviation"
applies
to
events
during
which
an
affected
source
fails
to
meet
a
compliance
option
or
comply
with
another
requirement
of
the
final
rule.
Deviations
are
not
synonymous
with
violations;
depending
on
the
circumstances,
a
deviation
may
or
may
not
be
a
violation
of
an
applicable
requirement.
We
agree
with
the
commenter
that
an
affected
source
need
not
be
in
compliance
with
compliance
options,
operating
requirements,
or
work
practice
requirements
during
periods
of
SSM.
Although
we
consider
noncompliance
with
the
compliance
options
during
SSM
to
be
deviations
from
the
compliance
options,
we
do
not
automatically
consider
these
deviations
to
be
violations
of
those
compliance
options.
Section
63.7(
e)(
1)
of
the
General
Provisions
to
Part
63
specifies
that,
"
Operations
during
periods
of
startup,
shutdown,
and
malfunction
shall
not
constitute
representative
conditions
for
the
purpose
of
a
performance
test,

nor
shall
emissions
in
excess
of
the
level
of
the
relevant
standard
during
periods
of
startup,

shutdown,
and
malfunction
be
considered
a
violation
of
the
relevant
standard
unless
otherwise
specified
in
the
relevant
standard
or
a
determination
of
noncompliance
is
made
under
40
CFR
63.6(
e)."
As
indicated
in
Table
10
of
the
final
rule,
this
language
of
the
General
Provisions
to
part
63
does
apply
to
subpart
DDDD.
The
definition
of
"
deviation"
included
in
the
final
rule
is
consistent
with
how
"
deviation"
is
defined
in
other
NESHAP,
and
has
not
been
changed
since
proposal.
Likewise,
we
do
not
agree
with
the
commenter
that
EPA
should
clarify
the
term
"
instance,"
since
adding
this
definition
as
the
commenter
recommended
would
narrow
the
scope
of
"
deviation"
to
non­
SSM
periods
only.

2.9
RECORDKEEPING
AND
REPORTING
REQUIREMENTS
2.9.1
Comment:
Commenter
IV­
D­
27
noted
that
although
it
is
helpful
for
EPA
to
explicitly
state
all
the
parameters
that
facilities
are
required
to
record
and
report,
EPA's
interpretation
of
the
requirements
of
the
general
MACT
provisions
combined
with
the
already
considerable
reporting
and
recordkeeping
provisions
required
by
the
proposed
PCWP
NESHAP
results
in
an
enormous
administrative
burden.
The
commenter
encouraged
EPA
to
do
whatever
possible
to
reduce
that
burden,
especially
for
smaller
facilities
that
will
be
forced
to
make
an
incredible
effort
to
make
sure
that
all
necessary
data
is
collected,
stored,
and
submitted
accurately
and
on
time.
Since
EPA
has
stated
that
reporting
lapses
are
"
knowing
and
willful
violations,"
it
2­
232
should
do
everything
it
can
to
make
sure
that
the
burden
on
smaller
facilities
is
not
unreasonable.

The
EPA
should
give
the
Administrator
flexibility
in
reviewing
alternative
reporting
methods
in
the
preamble
to
the
final
PCWP
rule
and
recognize
the
need
to
tailor
reporting
and
recordkeeping
requirements
to
meet
specific
facility
operating
and
control
scenarios
in
appropriate
sections
of
the
final
rule.

Response:
We
selected
the
proposed
reporting
and
recordkeeping
requirements
based
on
requirements
in
the
NESHAP
General
Provisions
(
40
CFR
part
63,
subpart
A).
Except
for
some
options
specific
to
the
PCWP
source
category
(
e.
g.,
emissions
averaging
options,
work
practices,

RCDME
option),
the
reporting
and
recordkeeping
requirements
are
the
same
as
the
requirements
in
the
General
Provisions.
Therefore,
we
believe
we
have
established
the
minimum
reporting
and
recordkeeping
requirements
necessary
to
ensure
enforcability
of
the
rule.
As
indicated
in
§
63.2291(
c)(
4),
the
Administrator
can
approve
alternative
reporting
and
recordkeeping
approaches
as
specified
in
§
§
63.10(
f)
and
63.90.

2.9.2
Comment:
Commenter
IV­
D­
27
requested
that
section
63.2271(
b)
(
How
do
I
demonstrate
continuous
compliance
with
the
compliance
options,
operating
requirements,
and
work
practice
requirements?)
should
be
revised
to
clearly
state
that
the
semiannual
compliance
report
does
not
need
to
include
extensive
detail
of
each
routine
maintenance
activity.
It
should
be
sufficient
to
list
process
uptime
versus
exempted
maintenance
downtime
as
a
comparison
to
the
relevant
exemption
percentage.
Also,
§
63.2281(
c)(
5)
(
What
reports
must
I
submit
and
when?)

should
be
updated
to
include
the
same
revision
as
section
63.2271(
b).

Response:
Section
68.2271(
b)
indicates
that
each
period
of
routine
control
device
maintenance
must
be
reported
according
to
§
63.2281.
Section
63.2281(
c)(
5)
requires
reporting
of
routine
control
device
maintenance.
Facilities
must
report
a
description
of
control
device
maintenance
performed
while
the
control
device
was
offline
and
one
or
more
of
the
process
units
controlled
by
the
control
device
was
operating.
The
description
must
include
the
date
and
time
when
the
control
device
was
shut
down
and
restarted;
identification
of
the
process
units
that
were
operating
and
the
number
of
hours
that
each
process
unit
operated
while
the
control
device
was
offline;
and
a
statement
of
whether
or
not
the
control
device
maintenance
was
included
in
the
facility's
approved
RCDME.
For
control
device
maintenance
covered
under
the
RCDME,

facilities
must
report
information
on
the
amount
of
time
that
the
control
device
was
offline
while
each
process
unit
routed
to
the
control
device
was
operating,
and
this
information
must
be
used
in
2­
233
calculating
the
annual
percentage
of
process
unit
uptime
during
which
the
control
device
is
down
for
routine
control
device
maintenance.
We
disagree
that
changes
to
the
reporting
and
recordkeeping
requirements
associated
with
the
RDCME
are
necessary,
because
all
of
the
information
reported
would
be
needed
by
permitting
authorities
to
evaluate
whether
the
maintenance
performed
fits
under
an
approved
request
for
an
RCDME
and
to
check
calculations
of
the
annual
percentage
of
process
unit
uptime
during
which
the
control
device
is
down
for
routine
control
device
maintenance.
We
further
note
that
use
of
an
RCDME
is
optional,
and
facilities
wishing
to
avoid
reporting
and
recordkeeping
associated
with
the
RCDME
can
opt
not
to
request
the
exemption.

2.9.3
Comment:
Commenter
IV­
D­
27
noted
that
there
is
currently
litigation
on
the
MACT
General
Provisions
regarding
the
requirement
to
report
details
for
SSM
events
that
follow
an
SSMP.
Section
63.2281(
c)(
4),
as
well
as
any
other
applicable
section,
should
be
revised
to
include
the
outcome
of
that
litigation.

Response:
The
General
Provisions
were
most
recently
updated
in
on
May
30,
2003
(
68
FR
32586).
One
of
the
sections
that
was
revised
was
§
63.10(
d)(
5)(
i),
which
addresses
the
recordkeeping
and
reporting
requirements
for
SSM
events.
As
noted
in
our
response
to
comment
No.
2.3.8.2,
facilities
are
required
to
describe
only
malfunctions
that
may
have
caused
the
facility
to
exceed
the
relevant
emission
standards,
not
all
SSM
events.
However,
as
the
commenter
pointed
out,
this
section
is
involved
in
litigation,
and
the
outcome
of
that
litigation
may
require
EPA
to
further
revise
the
General
Provisions.
Because
the
PCWP
NESHAP
incorporates
this
section
and
other
sections
of
the
General
Provisions
by
reference,
the
PCWP
NESHAP
will
be
considered
to
be
revised
if
those
sections
of
the
General
Provisions
are
revised
as
a
result
of
the
outcome
of
litigation.

2.9.4
Comment:
Commenter
IV­
D­
27
requested
that
§
63.2281(
e)(
1)
through
(
11)
be
revised
to
include
summary
reporting
as
an
option
because
the
current
requirements
are
excessive
in
view
of
the
MACT
General
Provisions
at
§
63.10(
e)(
3),
which
provide
for
the
reporting
of
only
summary
information
when
continuous
monitoring
system
(
CMS)
downtime
for
the
reporting
period
is
less
than
5
percent
of
the
total
operating
time
for
the
reporting
period.

Response:
Section
63.10(
e)(
3)
deals
with
excess
emissions
reports
and
does
not
apply
for
the
PCWP
NESHAP.
We
have
superceded
§
63.10(
e)(
3)
with
§
63.2281(
e),
which
requires
reporting
of
deviations
from
compliance
options
or
operating
requirements
when
a
CMS
is
used.
2­
234
The
reporting
requirements
included
in
§
63.2281(
e)(
1)
through
(
11)
are
similar
to
the
summary
report
requirements
listed
in
§
63.10(
e)(
3).
Section
63.2281(
e)
requests
only
summary
information
for
deviations
in
all
semiannual
compliance
reports,
not
just
those
reports
where
there
is
less
than
5
percent
CMS
downtime
during
the
reporting
period.

2.9.5
Comment:
Commenter
IV­
D­
27
recommended
a
change
to
section
63.2283(
a)
(
In
what
form
and
how
long
must
I
keep
my
records?).
Currently,
the
section
states
that
"
records
must
be
in
a
form
suitable
and
readily
available
for
expeditious
review."
However,
the
MACT
General
Provisions
are
not
helpful
in
determining
a
"
suitable"
form,
and
due
to
the
large
amount
of
records
that
will
be
generated
by
the
PCWP
rule,
many
facilities
may
utilize
technology
to
help
with
the
recording
and
storage
of
these
records.
If
these
records
happen
to
be
computerized
on
the
same
systems
that
control
the
process
operation,
control
devices,
or
other
systems,
then
the
records
may
not
be
readily
available.
The
commenter
suggested
the
following
revision
to
this
section:
"
Your
records
must
be
in
a
form
which
is
constructively
responsive
to
the
relevant
requirement
of
this
rule
and
available
for
review
within
a
reasonable
length
of
time
as
determined
by
the
scope
and
extent
of
the
relevant
records."

Response:
Section
63.2283(
a)
references
§
63.10(
b)(
1)
of
the
General
Provisions,
which
also
states
that
records
must
be
kept
"
in
a
form
suitable
and
readily
available
for
expeditious
inspection
and
review."
Section
63.10(
b)(
1)
further
states
that
the
oldest
three
years
of
data
files
may
be
kept
"
on
microfilm,
on
a
computer,
on
computer
floppy
disks,
on
magnetic
tape
disks,
or
on
microfiche."
We
disagree
that
the
commenter's
suggested
revision
to
§
63.2283(
a)
provides
more
clarity
than
the
General
Provisions,
and
therefore,
we
have
not
incorporated
the
commenter's
suggestion
into
§
63.2283(
a).
We
further
note
that
the
General
Provisions
have
been
recently
updated
to
clarify
requirements
as
needed.

2.10
COST
AND
ECONOMIC
ASSUMPTIONS
AND
IMPACTS
2.10.1
Cost
and
economic
impacts
2.10.1.1
Comment:
Commenter
IV­
D­
27
stated
that
EPA
estimated
an
annual
cost
of
$
142
million
with
annual
emission
reductions
of
11,000
tons
of
HAP,
yielding
an
average
cost
effectiveness
of
$
13,000
per
ton
of
HAP
removed.
The
commenter
compared
these
estimates
with
the
industry's
estimates
of
an
annual
cost
of
$
165
million
with
annual
emission
reductions
of
2­
235
approximately
9,000
tons
of
HAP,
yielding
an
average
cost
effectiveness
of
$
18,000
per
ton
of
HAP
removed.
The
commenter
noted
that,
although
their
methodology
and
EPA's
methodology
for
costing
are
substantially
different,
the
total
annual
cost
estimates
are
reasonably
close
and
are
assumed
to
be
reasonable
estimates.
The
commenter
presents
their
cost
analysis
(
see
section
XII.
A
of
comment
IV­
D­
27).
The
commenter
noted
that
proposed
options
such
as
emissions
averaging
and
PBCO
limits
and
the
commenter's
suggested
risk­
based
and
concentration
cutoff
options
could
lower
costs
for
facilities.
Also,
biofilters
or
RCOs
will
likely
be
used
by
some
facilities
and
these
technologies
may
also
lower
industry
cost.

Response:
We
acknowledge
this
comment
agreeing
that
our
cost
estimates
are
reasonable
estimates.

2.10.1.2
Comment:
Commenters
IV­
D­
02,
IV­
D­
15,
IV­
D­
17,
IV­
D­
36,
IV­
D­
38,

IV­
D­
44,
and
IV­
D­
40
argued
that
this
rule
is
extremely
expensive,
forcing
plants
to
choose
between
installing
expensive
controls
and
closing
their
doors.
It
is
especially
hard
on
plants
in
rural
areas
that
do
not
pose
much
of
a
risk
to
human
health
or
the
environment.
If
plants
are
forced
to
close,
then
plant
employees
as
well
as
those
who
depend
on
the
plant
for
their
living,

such
as
contractors,
consultants,
and
suppliers,
would
lose
their
jobs.
Local
property
values
would
decline
severely,
local
businesses
would
close,
and
the
areas
would
lose
their
chance
to
attract
new
residents
and
businesses.

Commenters
IV­
D­
15,
IV­
D­
16,
IV­
D­
53,
IV­
D­
50,
IV­
D­
39,
and
IV­
D­
42
reiterated
the
costs
estimated
by
EPA
for
installing
and
maintaining
the
necessary
HAP
controls
and
then
compared
that
amount
to
the
money
that
is
already
spent
on
the
plant
each
year.
Commenters
IVD
16,
IV­
D­
50,
and
IV­
D­
41
pointed
out
that
the
amount
of
money
associated
with
HAP
controls
is
almost
triple
the
annual
capital
spending
during
the
profitable
late
1990s.
Several
commenters
(
IV­
D­
08,
IV­
D­
09,
IV­
D­
53,
IV­
D­
39,
IV­
D­
41,
IV­
D­
50,
and
IV­
D­
42)
stated
that
companies
are
considering
shutting
down
plants
because
of
the
large
capital
and
operating
expenses
associated
with
installing
and
maintaining
HAP
controls.
Local
economies
would
be
severely
impacted
due
to
plant
closures.
Hundreds
of
people
would
lose
their
jobs,
including
the
plant
employees
and
employees
at
companies
that
rely
on
the
plywood
plant
for
business.

Commenters
IV­
D­
09,
IV­
D­
15,
IV­
D­
53,
and
IV­
D­
42
stated
that
the
PCWP
industry
has
not
been
profitable
lately;
20
percent
of
the
plants
that
existed
in
1999
have
closed
permanently
and
five
more
are
temporarily
idle.
Commenters
IV­
D­
08,
IV­
D­
09,
IV­
D­
15,
IV­
2­
236
D­
16,
IV­
D­
53,
IV­
D­
39,
IV­
D­
50,
IV­
D­
41,
and
IV­
D­
42
stated
that
the
estimate
that
only
one
plant
would
be
forced
to
close
because
of
this
rule
was
made
during
a
profitable
time
in
the
industry,
and
many
more
than
that
would
close
in
these
less
profitable
times
if
the
rule
were
finalized
without
changes.
The
PCWP
industry
has
not
been
profitable
lately,
and
the
future
is
uncertain
for
many
facilities.
Several
commenters
also
stated
that
it
is
safe
to
assume
that
Congress
did
not
intend
for
this
rule
to
result
in
the
addition
of
exceptionally
costly
controls
that
would
yield
minimal,
if
any,
health
and
environmental
benefits,
which
is
precisely
what
EPA's
analysis
indicates
will
be
the
most
likely
result
if
the
proposed
rule
is
implemented.
Commenters
IV­
D­
09,
IV­
D­
16,
and
IV­
D­
41
asked
why
EPA
did
not
attempt
to
scuttle
this
burdensome
and
counterproductive
rule
when
the
analysis
showed
that
compliance
would
be
costly
and
would
not
have
significant
health
or
environmental
effects.

Commenters
IV­
D­
08,
IV­
D­
09,
IV­
D­
15,
IV­
D­
16,
IV­
D­
39,
IV­
D­
41,
IV­
D­
42,
IV­
D­

53,
and
IV­
D­
50
argued
that
foreign
plants
are
becoming
major
competition
in
the
United
States.

These
plants
are
not
required
to
control
their
emissions,
so
if
U.
S.
plants
were
forced
to
add
unnecessary
controls,
they
would
no
longer
be
competitive
in
the
global
market,
and
the
domestic
industry
would
suffer.

For
perspective,
commenter
IV­
D­
09
stated
that
their
plant
is
one
of
the
more
efficient,

and
it
is
still
losing
money
due
to
current
market
conditions.

Commenter
IV­
D­
14
stated
that
one
of
its
plywood
mills
was
closed
in
2000
and
that
the
proposed
rule
would
probably
force
its
two
remaining
mills
to
close
as
well.
All
three
mills
are
small
to
medium­
sized
and
located
in
small
towns,
and
the
closure
of
the
first
mill
was
harmful
to
the
town's
economy.

Commenter
IV­
D­
16
stated
that
their
area
is
still
dealing
with
the
aftermath
of
the
Mt.

Saint
Helens
eruption
in
1980.

Commenter
IV­
D­
19
argued
that
EPA
has
not
accurately
assessed
the
effects
of
this
rule
on
the
industry,
especially
plants
that
are
the
major
employer
in
rural
areas.
Some
plants
that
would
need
controls
have
already
closed
in
anticipation
of
the
rule.
The
commenter
presented
a
monetary
cost
estimate
for
the
company
of
$
100
million
in
capital
costs
and
$
10.6
million
annually
for
natural
gas
and
additional
electricity.

Commenters
IV­
D­
34
and
IV­
D­
35
stated
that
more
facilities
will
shut
down
than
expected
if
this
rule
is
finalized.
If
a
facility
is
not
making
a
profit
before
MACT
standards
are
2­
237
applied,
there
is
no
way
that
the
facility
will
be
able
to
make
a
profit
once
MACT
standards
are
enforced.
The
EPA
predicted
that
only
one
plant
would
shut
down,
but
many
more
facilities
than
that
will
be
unable
to
afford
the
HAP
controls
and
will
be
forced
to
close,
disrupting
the
economies
of
the
surrounding
areas.

Commenter
IV­
D­
47
noted
that
they
were
already
forced
to
claim
Chapter
11
bankruptcy
for
several
reasons,
including
environmental
restraints,
undercapitalization,
and
poor
market
conditions.
If
their
one
remaining
plywood
facility
is
affected
by
the
PCWP
rule,
the
company
will
no
longer
exist
and
the
results
will
be
devastating
to
the
local
economy.
Many
other
plywood
mills
will
be
forced
to
close
as
well.

Response:
Section
112(
b)
of
the
CAA
contains
a
list
of
HAP
that
are
pollutants
that
are
known
to
cause
or
may
reasonably
be
anticipated
to
cause
adverse
effects
to
humans
or
the
environment.
Section
112(
c)
of
the
CAA
requires
us
to
list
categories
and
subcategories
of
major
and
area
sources
of
HAP
and
to
establish
NESHAP
for
the
listed
source
categories
and
subcategories.
Major
sources
of
HAP
are
those
stationary
sources
or
groups
of
stationary
sources
that
are
located
within
a
contiguous
area
under
common
control
that
emit
or
have
the
potential
to
emit,
considering
controls,
9.07
Mg/
yr
(
10
tpy)
or
more
of
any
one
HAP
or
22.68
Mg/
yr
(
25
tpy)
or
more
of
any
combination
of
HAP.
Area
sources
are
those
stationary
sources
or
groups
of
stationary
sources
that
are
not
major
sources.

Plywood
and
particleboard
manufacturing
was
listed
as
a
category
of
major
sources
on
the
initial
source
category
list
published
in
the
Federal
Register
on
July
16,
1992
(
57
FR
31576).
The
name
of
the
source
category
was
changed
to
plywood
and
composite
wood
products
(
PCWP)
on
November
18,
1999
(
64
FR
63025)
to
more
accurately
reflect
the
types
of
manufacturing
facilities
covered
by
the
source
category.
The
PCWP
source
category,
which
includes
major
sources
of
HAP
emissions,
emits
HAP
including
(
but
not
limited
to)
acetaldehyde,
acrolein,
formaldehyde,

methanol,
phenol,
and
propionaldehyde.
These
six
HAP
are
associated
with
a
variety
of
adverse
health
effects,
including
chronic
health
disorders
(
e.
g.,
damage
to
nasal
membranes,
reproductive
disorders,
and
problems
with
pregnancies)
and
acute
health
disorders
(
e.
g.,
irritation
of
eyes,

throat,
and
mucous
membranes;
dizziness;
headache;
and
nausea).
Three
of
the
six
HAP
listed
above
have
been
classified
as
probable
or
possible
human
carcinogens.

Because
PCWP
manufacturing
is
a
source
category
containing
major
sources
of
HAP,
we
are
required
by
the
CAA
to
establish
NESHAP
for
PCWP
manufacturing.
Standards
for
the
2­
238
PCWP
manufacturing
source
category
were
proposed
in
the
Federal
Register
on
January
9,
2003
(
68
FR
1276).
These
PCWP
standards
implement
section
112(
d)
of
the
CAA
by
requiring
all
major
sources
subject
to
the
rule
to
meet
HAP
emission
standards
reflecting
the
application
of
MACT.
The
MACT
floor
is
the
minimum
control
level
allowed
for
NESHAP
and
is
defined
under
section
112(
d)(
3)
of
the
CAA.
In
essence,
the
MACT
floor
ensures
that
the
standard
is
set
at
a
level
that
ensures
that
all
major
sources
achieve
a
level
of
control
at
least
as
stringent
as
that
already
achieved
by
the
better­
controlled
and
lower­
emitting
sources
in
each
source
category
or
subcategory.
For
new
sources,
the
MACT
floor
cannot
be
less
stringent
than
the
emission
control
that
is
achieved
in
practice
by
the
best­
controlled
similar
source.
The
MACT
standards
for
existing
sources
can
be
less
stringent
than
standards
for
new
sources,
but
they
cannot
be
less
stringent
than
the
average
emission
limitation
achieved
by
the
best­
performing
12
percent
of
existing
sources
in
the
category
or
subcategory
(
or
the
best­
performing
5
sources
for
categories
or
subcategories
with
fewer
than
30
sources).
In
developing
MACT,
section
112(
d)(
2)
of
the
CAA
requires
us
to
also
consider
any
control
options
that
are
more
stringent
than
the
floor
("
beyond­
the­
floor"
options).
We
may
establish
beyond­
the­
floor
options
based
on
the
consideration
of
cost
of
achieving
the
emissions
reductions,
any
non­
air
quality
health
and
environmental
impacts,
and
energy
requirements.

Section
112(
d)(
3)
of
the
CAA
does
not
give
EPA
the
discretion
to
consider
costs,

domestic
or
foreign
market
conditions,
non­
HAP
air
impacts,
or
energy
use
at
the
MACT
floor
control
level.
However,
§
112(
d)(
2)
of
the
CAA
requires
EPA
to
consider
cost,
non­
air
quality
health
impacts,
environmental
impacts,
and
energy
requirements
when
reviewing
beyond­
the­
floor
control
options.
We
acknowledge
the
commenters'
concerns
regarding
the
cost
of
the
PCWP
standards.
However,
there
are
many
existing,
well­
controlled
PCWP
process
units
that
formed
the
basis
for
our
MACT
floor
determinations.
We
determined
that
beyond­
the­
floor
control
measures
would
not
be
appropriate
for
most
PCWP
process
units
either
because
the
control
equipment
that
formed
the
basis
of
the
MACT
floor
is
the
best
control
equipment
available
or
because
of
cost.
Thus,
we
have
minimized
the
costs
of
this
rule
to
the
greatest
extent
allowed
under
the
CAA.

We
note
that
most
of
the
above
commenters
manufacture
softwood
plywood.
We
acknowledge
that
softwood
plywood
is
a
sector
of
the
PCWP
industry
that
has
been
facing
economic
pressures
associated
with
increased
competition
from
another
PCWP
product
(
OSB).
2­
239
The
softwood
plywood
market
is
declining
for
reasons
other
than
this
NESHAP.
The
CAA
does
not
allow
us
to
consider
costs
or
the
status
of
a
product
market
when
establishing
emissions
standards
at
the
MACT
floor
control
level.
Because
many
existing
softwood
veneer
dryers
already
have
incineration­
based
controls,
softwood
plywood
plants
are
affected
by
the
MACT
floor
requirement
for
softwood
veneer
dryer
heated
zones
to
meet
an
emission
level
achievable
with
incineration­
based
controls.
Unlike
for
reconstituted
wood
products,
the
PCWP
rule
does
not
require
control
of
softwood
plywood
presses.

2.10.1.3
Comment:
Commenter
IV­
D­
05
requested
that
EPA
re­
analyze
the
economic
impact
data
to
reflect
current
times
rather
than
the
late
1990s.
Many
of
the
data
used
in
the
original
analysis
came
from
plants
that
are
now
shut
down.
The
ones
that
are
left
are
dealing
with
high
energy
costs,
competition
from
foreign
markets
that
follow
different
rules,
raw
materials
increases,
high
transportation
costs,
energy
crises,
and
shrinking
markets.
Another
review
of
the
data
could
help
to
determine
how
many
plants
would
close
because
of
the
high
