­­­
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
\
J
4
6
1
REGION
IX
75
Hawthorne
Street
San
Francisco,
CA
94105
March
11,2003
MEMORANDUM
From:
Lily
Wong
Rulemaking
Office,
Air
Division
To:
Docket
OAR­
2002­
0076
L­­­

I
EPA
AF
DL'C
'<
T
L­~

The
WESTAR
Model
Rule/
MOU
Workgroup
was
tasked
by
the
Western
Regional
Air
Partnership
to
complete
the
work
on
the
draft
model
rule
and
MOU.
In
the
course
of
almost
weekly
conference
calls
of
the
Workgroup
during
the
fall
of
2002,
the
Workgroup
decided
that
10
years
would
be
the
appropriate
duration
for
retaining
records
during
the
pre­
trigger
phase
of
the
backstop
SO2trading
program.
The
reason
10
years
was
considered
necessary
was
because
of
1)
the
emissions
averaging
provision,
and
2)
the
inherent
lag
time
in
determining
whether
regional
emissions
were
above
or
below
the
milestone.

For
instance,
a
record
created
in
2003
documenting
a
source's
emissions
would
be
relied
on
for
determining
the
amount
of
the
2005
regional
emissions,
since
regional
emissions
are
really
a
3­
yr
average
(
in
this
case,
2005,2004,
and
2003).
The
actual
determinationof
whether
the
2005
regional
emissions
were
above
or
below
the
milestone
would
not
occur
until
March
2007.
Records
should
be
retained
for
5
years
beyond
when
the
record
was
relied
upon
for
a
regulatory
determination.
Five
years
beyond
March
2007
would
be
March
2012,
essentially
10
years
after
the
record
was
created.

The
10
year
record
retention
requirement
was
also
discussed
during
the
Market
Trading
Forum
meeting
on
December
11­
12,2002
in
Denver.
Stakeholders
acknowledged
the
appropriatenessof
the
provision
and
suggested
that
40
CFR
51.309
be
clear
on
this
requirement.
