Document ID: EPA-HQ-OAR-2005-0159-0014
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-03-10T05:00Z

Final
April
19,
2005
Page
1
of
1
Page
White
Paper
#
1:
What
Pollutants
Should
a
Revised
Natural
Events
Policy
(
NEP)
Cover?

Date/
Status:
April
19,
2005
Final
Background:
The
existing
Natural
Events
Policy
(
NEP)
applies
only
to
exceedances
of
the
PM10
National
Ambient
Air
Quality
Standard
(
NAAQS)
caused
by
high
wind
events,
seismic
and
volcanic
activities,
and
wildfire
events.
Since
the
existing
NEP
was
developed,
EPA
has
implemented
the
NAAQS
for
PMfine
(
PM2.5)
and
is
currently
reviewing
the
existing
PM2.5
NAAQS
and
the
need
for
a
PMcoarse
or
other
PM
NAAQS.

Discussion:
Recognizing
that
uncontrollable
natural
events
can
have
a
deleterious
effect
on
air
quality
and
attainment
of
the
NAAQS,
EPA
issued
the
NEP
on
May
30,
1996.
The
NEP
was
developed
as
a
way
to
flag
data
in
an
area
that,
but
for
the
natural
event,
would
be
attaining
the
NAAQS.
The
NEP
lays
out
the
timetable
and
procedures
by
which
States
flag
monitoring
data
that
is
collected
during
natural
events,
including
high
winds,
seismic
and
volcanic
activities,
and
wildfires.

In
the
past
few
years,
several
States
have
worked
with
EPA
regional
offices
to
flag
data
that
was
affected
by
natural
events.
Based
on
the
experience
gained
through
those
efforts,
several
western
states
suggested
that
the
NEP
be
modified
to
better
facilitate
meeting
the
intent
of
the
NEP.
However,
revising
the
NEP
was
delayed
based
on
the
assumption
that
a
revision
would
be
required
as
a
result
of
the
implementation
of
new
NAAQS
for
PM2.5
and
possibly
PMcoarse,
and
it
was
agreed
that
these
issues
would
be
addressed
at
that
time.

Implementation
of
the
PM2.5
NAAQS
is
well
under
way,
although
EPA
is
currently
reviewing
that
standard,
as
well
as
the
need
for
a
PMcoarse
NAAQS.
Because
the
NEP
does
not
specifically
address
PM2.5
or
PMcoarse,
EPA
has
used
its
legal
creativity
to
extend
the
current
policy
to
include
PM2.5
and
the
policy
has
not
been
revised;
however,
if
that
creativity
is
successfully
challenged,
it
is
the
States
who
will
be
responsible
to
develop
the
resulting
State
Implementation
Plans.

Since
the
NEP
was
developed,
EPA
has
also
developed
the
PM10
Limited
Maintenance
Plan
option
and
rules
for
implementation
of
the
Regional
Haze
requirements
of
the
Clean
Air
Act.
These
issues
were
not
considered
when
the
NEP
was
developed.

Recommendation:

The
NEP
should
be
revised
to
specifically
include
all
forms
of
PM,
including
PM2.5
and
PMcoarse.

Task
Group
Members:

Dave
McNeill,
Utah 
author
Doug
Schneider,
Washington 
reviewer