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MEMORANDUM
July
7,
2003
To:
Docket
File
From:
Rebecca
L.
Nicholson
Subject:
Telephone
Conference
between
Rebecca
L.
Nicholson
(
RTI),
Phil
Ferguson
(
International
Paper)
and
David
Word
(
NCASI)
on
AF&
PA
Comments
on
Proposed
Plywood
and
Composite
Wood
Products
MACT
Mr.
Ferguson
asked
Ms.
Nicholson
whether
EPA
was
considering
incorporating
the
AF&
PA
comments
concerning
the
use
of
zeros
for
non­
detect
measurements
of
hazardous
air
pollutants
(
HAP).
(
The
proposed
rule
would
require
sources
to
treat
all
non­
detect
measurements
as
being
equal
to
one­
half
the
detection
limit.)
Ms.
Nicholson
replied
that
EPA
was
considering
all
of
the
comments.
She
restated
EPA's
historical
concerns
regarding
the
use
of
zeros
for
nondetect
measurements,
namely
that
testing
contractors
may
set
the
detection
limits
during
testing
at
inappropriately
high
levels
(
resulting
in
non­
detect
measurements
at
sources
with
detectable
emissions)
and
that
emission
reduction
efficiency
measurements
across
control
devices
would
be
artificially
elevated
(
e.
g.,
if
outlet
emissions
considered
"
zero"
then
calculated
control
efficiency
would
be
100
percent).
Mr.
Ferguson
and
Dr.
Word
responded
that,
from
their
perspective,
the
request
by
AF&
PA
to
use
zero
for
non­
detect
measurements
was
intended
for
uncontrolled
sources
only
(
i.
e.,
uncontrolled
sources
that
would
be
complying
with
production­
based
compliance
options
or
uncontrolled
sources
that
would
be
part
of
an
emissions
averaging
plan).
Therefore,
they
argued
that
the
issue
regarding
calculation
of
elevated
control
efficiencies
would
not
apply
in
this
case.
Regarding
the
potential
for
test
contractors
to
set
unacceptably
high
detection
limits,
Dr.
Word
suggested
that
EPA
could
only
allow
sources
to
claim
non­
detect
data
as
"
zero"
if
the
detection
limit
during
the
testing
was
set
at
some
maximum
value
(
e.
g.,
1
ppm).
He
noted
that,
for
the
pollutants
of
interest,
the
detection
limits
achievable
with
FTIR
are
around
1
ppm,
and
the
detection
limits
achievable
with
the
NCASI
method
are
between
0.33
and
0.5
ppm.
He
further
noted
that
EPA
Method
0011
can
achieve
even
lower
detection
limits;
however,
this
method
is
only
valid
for
measuring
formaldehyde.
Dr.
Word
also
pointed
out
that
the
AF&
PA
comments
included
an
alternative
to
the
"
non­
detect
equals
zero"
recommendation
whereby
the
non­
detect
value
would
be
treated
as
one­
half
the
detection
limit
(
as
proposed),
but
then
a
90
percent
reduction
would
be
applied
to
that
value,
in
keeping
with
how
the
productionbased
compliance
options
were
developed.
Ms.
Nicholson
stated
that
EPA
would
consider
all
of
the
options
recommended
by
AF&
PA
in
their
comments,
including
the
revised
option
for
treating
non­
detect
as
zero
discussed
during
the
teleconference
(
i.
e.,
adding
a
cap
on
the
detection
limit).
She
noted
that,
to
assist
EPA
with
their
decision
on
this
issue,
RTI
would
perform
calculations
using
actual
emissions
data
to
show/
compare
the
effect
of
each
method
on
the
calculated
emissions
rate.
