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UNITED
STATES
ENVIRONMENTAL
PROTECTIONAGENCY
REGION
IX
75
Hawthorne
Street
San
Francisco,
CA
94105
April
2,2003
MEMORANDUM
From:
Lily
Wong
Rulemaking
Office,
Air
Division
To:
Docket
OAR­
2002­
0076
The
WESTAR
Model
RuleMOU
Workgroup
was
tasked
by
the
Western
Regional
Air
Partnership
to
complete
the
work
on
the
draft
model
rule
and
MOU.
In
the
course
of
conference
calls
in
July
and
August
of
2002,
the
Workgroup
raised
several
issues
relating
to
the
milestones.

There
is
a
timing
issue.
The
states
and
tribes
that
intend
to
submit
section
309
regional
haze
implementation
plans
by
December
2003
will
begin
their
process
to
adopt
implementation
plans
in
the
spring
and
summer
of
2003.
At
that
time,
it
will
not
be
clear
which
states
and
tribes
have
definitively
decided
to
opt
into
the
309
program.
Also,
tribes
are
not
subject
to
the
December
2003
deadline
and
may
opt
in
at
any
time.
Because
the
milestones
are
based
on
states
and
tribes
that
have
opted
into
the
309
program
(
or
conversely,
the
emissions
fiom
a
given
state
or
tribe
that
has
not
opted
into
the
309
program
will
be
deducted
from
the
regional
milestones),
it
is
unclear
what
the
milestones
will
be
when
the
states
and
tribes
are
developing
their
implementation
plan.
Consequently,
the
Workgroup
believed
that
it
would
be
best
to
include
all
necessary
information
and
formulas
to
calculate
the
milestone,
but
not
specify
the
milestone.
The
actual
calculation
of
the
milestone
would
occur
on
an
annual
basis
once
it
is
clear
which
states
and
tribes
have
opted
into
the
309
program.

The
states
and
tribes
opting
into
309
are
adopting
implementation
plans
which
govern
activities
within
their
jurisdiction.
The
program
only
becomes
a
federally
enforceable
regional
program
when
EPA
approves
each
state
and
tribal
implementation
plan.
The
program
includes
an
annual
process
where
states
and
tribes
are
required
to
make
a
determination
of
the
milestone
for
a
given
year,
and
compare
regional
emissions
against
that
milestone
to
determine
if
regional
emissions
have
exceeded
the
milestone.
If
regional
emissions
have
exceeded
the
milestone,
the
states
and
tribes
are
required
to
implement
the
trading
program.
The
Workgroup
believed
that
the
determination
of
the
milestone
should
be
based
on
the
number
of
states
and
tribes
that
have
approved
implementation
plans
by
a
specified
date.
For
example,
the
2003
milestone
would
be
the
9­
state
regional
milestone,
minus
all
the
emissions
(
from
the
state
and
tribal
opt­
out
tables)
from
states
and
tribes
which
do
not
have
approved
309
programs
as
of
December
3
1,2004.
While
the
states
and
tribes
may
also
compare
(
for
informational
purposes)
the
regional
emissions
to
a
milestone
based
on
states
and
tribes
that
have
submitted
but
do
not
have
approved
309
implementation
plans,
such
a
comparison
would
be
an
academic
exercise
and
could
not
be
used
to
determine
whether
the
backstop
trading
program
has
been
triggered
as
required
by
the
approved
309
implementation
plans.

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