March
9,
2006
Lydia
Wegman
US
EPA
RTP,
Mail
Code
C504­
01
Research
Triangle
Park,
NC
7711
RE:
Exceptional
and
Natural
Event
Rulemaking
Dear
Ms.
Wegman:

Idaho,
like
many
other
western
states,
occasionally
experiences
air
quality
episodes
that
are
strongly
influenced
by
natural
events
such
as
wildfire
smoke
and
windblown
dust.
In
order
to
preserve
data
integrity
and
not
have
the
episodes
trigger
unnecessary
regulatory
actions,
Idaho
has
used
the
existing
natural
event
policy
to
flag
PM10
data
accordingly.
As
such,
Idaho
is
very
interested
in
the
extension
of
these
policies
to
other
criteria
pollutants,
especially
PM2.5
and
ozone.
The
recent
decision
by
the
Environmental
Protection
Agency
(
EPA)
to
convert
the
existing
guidance
policies
into
rules
has
made
Idaho
even
more
interested
in
the
process.

The
Idaho
Department
of
Environmental
Quality
(
IDEQ)
actively
participated
in
the
WESTAR
workgroup
that
earlier
this
year
submitted
a
list
of
recommendations
on
the
Natural
Events
Policy
to
STAPPA/
ALAPCO
and
then
to
EPA.
IDEQ
strongly
supports
the
recommendations
that
were
developed
by
WESTAR
and
encourages
EPA
to
consider
these
recommendations
in
this
rulemaking
process.
Attached
is
a
copy
of
the
WESTAR
Natural
Events
Policy
recommendations
for
your
consideration.

Thank
you
for
the
opportunity
to
provide
early
input
on
this
rulemaking
process.
IDEQ
looks
forward
to
reviewing
the
draft
documents
as
they
become
available
and
will
provide
additional
comments
during
the
official
public
comment
period
if
necessary.

Sincerely,

Martin
Bauer,
Administrator
Air
Quality
Division
MB:
DR:
pah
c:
Larry
Wallace,
USEPA
Amy
Royden­
Bloom,
STAPPA/
ALAPCO
Dan
Johnson,
WESTAR
Reading
File
