1
MEMORANDUM
DATE:
June
27,
2005
SUBJECT:
Emission
Standards
for
Emergency
Stationary
CI
Engines
FROM:
Melanie
Taylor,
Alpha­
Gamma
Technologies,
Inc.

TO:
Sims
Roy,
EPA
OAQPS
ESD
Combustion
Group
The
purpose
of
this
memorandum
is
to
provide
the
rationale
used
to
establish
the
emission
standards
for
emergency
engines,
including
fire
pump
engines,
in
the
proposed
new
source
performance
standards
(
NSPS)
for
stationary
compression
ignition
(
CI)
internal
combustion
engines
(
ICE).
An
emergency
stationary
CI
internal
combustion
engine
is
defined
in
the
proposed
NSPS
as
a
stationary
internal
combustion
engine
whose
operation
is
limited
to
emergency
situations,
maintenance
checks,
and
readiness
testing.
Examples
include
stationary
ICE
used
to
produce
power
for
critical
networks
or
equipment
(
including
power
supplied
to
portions
of
a
facility)
when
electric
power
from
the
local
utility
is
interrupted,
or
stationary
ICE
used
to
pump
water
in
the
case
of
fire
or
flood,
etc.
Examples
also
include
stationary
ICE
used
during
Federal
or
State
declared
disasters
and
emergencies,
and
simulations
of
emergencies
by
Federal,
State,
or
local
governments.

Emission
Standards
for
Emergency
Engines
For
engines
with
a
displacement
of
less
than
10
liters
per
cylinder,
the
emission
standards
in
the
proposed
NSPS
are
primarily
based
on
the
EPA
standards
for
nonroad
diesel
engines.
The
emission
standards
for
engines
with
a
displacement
between
10
and
30
liters
per
cylinder
in
the
NSPS
are
based
on
the
EPA
standards
for
marine
diesel
engines.
The
standards
for
nonroad
and
marine
diesel
engines
are
phased
in
over
several
years
and
have
Tiers
with
increasing
levels
of
stringency.
Engines
are
separated
into
engine
power
ranges,
and
some
emission
standards
vary
between
ranges.
The
basis
for
this
is
EPA's
analysis
of
the
applicability
of
specific
emission
control
strategies
for
each
power
range
of
engines.
The
Tier
2
and
Tier
3
standards
for
nonroad
diesel
engines
and
the
Tier
2
standards
for
marine
engines
are
based
on
the
most
advanced
engine­
based
technologies
available
for
the
various
engines
classes
in
the
timeframe
of
the
nonroad
and
marine
diesel
engine
rulemakings.
For
most
nonroad
diesel
engines,
the
Tier
4
levels
represent
the
emission
reductions
possible
from
the
application
of
catalyzed
diesel
particulate
filters
(
CDPF)
and
nitrogen
oxides
(
NOx)
adsorbers
to
the
expected
emission
levels
for
the
previous
tier
engines.
The
Tier
4
2
particulate
matter
(
PM)
standard
for
nonroad
diesel
engines
below
25
horsepower
(
HP)
and
the
Tier
4
NOx
standard
for
nonroad
diesel
engines
below
75
HP
are
not
based
on
the
application
of
add­
on
emission
control.
Tier
4
standards
for
marine
engines
have
not
been
promulgated
at
this
time.
The
EPA
is
currently
reviewing
the
possibility
of
promulgating
more
stringent
standards
for
marine
engines
similar
to
the
Tier
4
standards
promulgated
for
land
based
nonroad
CI
engines.
In
that
context,
the
EPA
will
review
whether
such
technologies
are
appropriate
for
stationary
CI
ICE
with
a
displacement
between
10
and
30
liters
per
cylinder.
The
NSPS
for
such
engines
may,
therefore,
be
revised
at
that
time
to
require
more
stringent
standards
in
the
future.

The
EPA
believes
that
it
is
appropriate
to
base
the
standards
for
most
stationary
CI
engines
on
the
nonroad
and
marine
diesel
engine
standards
because
the
design
and
emissions
characteristics
of
the
engines
are
very
similar.
Engine
manufacturers
have
indicated
to
EPA
that
in
most
cases
they
do
not
separately
design
and
manufacture
separate
CI
engines
for
stationary
use,
and
they
often
sell
the
same
CI
engine
for
use
in
nonroad
and
marine
equipment
as
they
do
for
use
in
stationary
applications.
Most
CI
engines
that
are
ultimately
used
in
stationary
applications
are
designed
and
built
for
use
in
both
stationary
and
nonroad/
marine
applications.
Engine
manufacturers
indicated
that
stationary
CI
engines
with
a
displacement
of
less
than
10
liters
per
cylinder
were
similar
to
nonroad
diesel
engines,
and
stationary
CI
engines
with
a
displacement
of
10
liters
per
cylinder
or
more
were
similar
to
marine
diesel
engines.

The
EPA
expects
that
even
if
there
were
no
NSPS
for
stationary
CI
engines,
emissions
from
those
engines
would
generally
decline
in
step
with
the
decreasing
emissions
from
nonroad
and
marine
engines,
since
many
stationary
engines
are
similar
to
nonroad
and
marine
engines.
The
EPA
believes
that
this
would
be
true
until
the
Tier
4
standards
that
are
based
on
add­
on
control
take
effect;
without
the
NSPS,
engine
manufacturers
would
not
equip
stationary
engines
with
add­
on
controls.
As
part
of
the
NSPS
rulemaking
process,
the
EPA
evaluated
the
cost
of
control
per
ton
of
pollutant
reduced
that
would
result
from
requiring
stationary
engines
to
be
equipped
with
add­
on
controls
that
would
reduce
emissions
to
meet
the
Tier
4
emission
standards.
The
cost
per
ton
analysis
is
presented
in
the
memorandum
entitled
"
Cost
per
Ton
for
NSPS
for
Stationary
CI
ICE."
In
that
memo,
the
cost
per
ton
of
CDPF
and
NOx
adsorber
was
evaluated
for
both
emergency
and
prime
(
non­
emergency)
engines.
Prime
engines
are
estimated
to
operate
approximately
1,000
hours
per
year,
while
emergency
engines
operate
an
estimated
37
hours
per
year.
Because
emergency
stationary
CI
engines
are
only
operated
for
a
few
hours
each
year,
emissions
from
these
engines
are
relatively
low
compared
to
emissions
from
prime
engines.
The
cost
of
control
per
ton
of
pollutant
reduced
is
therefore
much
higher
for
emergency
engines.

The
EPA
determined
that
the
relatively
high
cost
of
control
as
compared
to
the
amount
of
pollutant
reduced
did
not
justify
the
selection
of
add­
on
controls
for
emergency
engines.
The
emission
standards
for
emergency
engines
are
therefore
based
on
the
most
stringent
standards
that
do
not
require
add­
on
emission
controls.
The
basis
for
the
proposed
standards
is
as
follows:
3
 
For
emergency
stationary
CI
engines
with
a
displacement
of
less
than
10
liters
per
cylinder,
the
proposed
standards
are
based
on
the
Tier
2
and
3
nonroad
diesel
engine
standards,
except
that
for
emergency
engines
less
than
25
HP,
the
proposed
standards
are
based
on
the
Tier
4
PM
standard
for
nonroad
diesel
engines
below
25
HP,
and
for
emergency
engines
less
than
75
HP,
the
proposed
standards
are
based
on
the
Tier
4
NOx
standard
for
nonroad
diesel
engines
below
75
HP.
 
For
emergency
stationary
CI
engines
with
a
displacement
of
10
liters
per
cylinder
or
more,
the
proposed
standards
are
based
on
the
Tier
2
marine
diesel
engine
standards.

Fire
Pump
Engines
Stationary
CI
fire
pump
engines
are
a
subset
of
emergency
engines.
Fire
pump
engines
are
emergency
stationary
CI
engines
certified
to
National
Fire
Protection
Association
(
NFPA)
requirements
that
are
used
to
provide
power
to
pump
water
for
fire
suppression
or
protection.
During
the
NSPS
rulemaking
process,
EPA
met
with
Clarke
Fire
Protection
Products,
a
leading
provider
of
fire
pump
engines.
Representatives
from
John
Deere
and
Moore
Pump
and
Equipment
also
attended
one
of
the
meetings.

During
the
initial
meeting
with
Clarke,
EPA
presented
the
potential
emission
standards
for
emergency
engines,
which
have
been
discussed
previously
in
this
memorandum.
The
fire
pump
engine
supplier
stated
that
engine
manufacturers
would
not
be
able
to
produce
fire
pump
engines
that
could
meet
the
Tier
2
emission
standards
in
the
timeframe
proposed
by
EPA.
Also,
according
to
Clarke,
additional
time
is
needed
to
meet
the
Tier
3
levels,
because
engines
must
be
designed,
certified,
and
manufactured
to
meet
the
specifications
of
NFPA
20
(
Standard
for
the
Installation
of
Stationary
Pumps
for
Fire
Protection),
which
requires
the
engine
to
be
certified
by
independent
certifying
organizations
such
as
Underwriters
Laboratory
and
Factory
Mutual.
This
is
a
process
that
takes
approximately
3
years.
Clarke
also
indicated
that
high
speed
engines,
which
are
engines
with
a
rated
speed
of
2,560
revolutions
per
minute
or
greater,
would
need
even
more
time
to
comply
with
the
Tier
3
standards.

According
to
Clarke,
high
speed
engines
allow
the
fire
pump
to
produce
greater
output
water
pressures,
eliminating
the
need
for
a
second
pump.
Furthermore,
Clarke
indicated
that
many,
if
not
all,
of
these
high
speed
engines
are
not
replaceable
with
similar
engines
that
meet
EPA's
emission
standards.
Clarke
indicated
that
it
may
be
able
to
produce
high
speed
emergency
fire
pump
engines
that
meet
Tier
3
emission
standards
if
an
additional
3
years
are
provided
in
addition
to
the
extra
3
years
needed
for
emergency
fire
pump
engines
that
are
not
high
speed
engines
to
meet
Tier
3
emission
standards.
In
other
words,
high
speed
emergency
fire
pump
engines
would
be
given
up
to
6
additional
years
to
meet
Tier
3
emission
standards
after
the
timeframe
that
other
stationary
CI
engines
that
are
not
fire
pump
engines
would
be
required
to
meet
Tier
3
levels.

Emergency
fire
pump
engines
account
for
a
small
percentage
of
all
stationary
CI
4
emergency
engines.
According
to
EPA
estimates,
emergency
fire
pump
engines
represent
about
3
percent
of
stationary
CI
emergency
engines.
Resulting
emissions
by
allowing
certain
emergency
fire
pump
engines
to
skip
Tier
2
and
providing
additional
time
to
comply
with
the
proposed
Tier
3
emission
standards
are
therefore
minimal
with
respect
to
the
emissions
from
all
stationary
CI
emergency
engines.
The
EPA
believes
it
is
appropriate
to
allow
certain
emergency
fire
pump
engines
to
skip
Tier
2
and
be
given
additional
time
to
comply
with
the
Tier
3
emission
standards
of
the
proposed
NSPS,
as
discussed
above.
For
emergency
fire
pump
engines
where
there
is
no
Tier
3
emission
standard,
i.
e.,
engines
less
than
50
HP
and
engines
greater
than
600
HP,
EPA
has
provided
additional
time
to
comply
with
the
Tier
2
level.
Stationary
CI
fire
pump
engines
are
used
in
critical
situations
for
life
safety
purposes
and
EPA
believes
that
the
proposed
allowances
will
ensure
that
the
emergency
fire
pump
development
process
is
not
compromised
and
will
provide
sufficient
time
to
develop
fire
pumps
that
meet
the
requirements
of
NFPA
and
EPA's
proposed
emission
standards.
