OFFICE
OF
AIR
AND
RADIATION
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
NATIONAL
VEHICLE
AND
FUEL
EMISSIONS
LABORATORY
2565
PLYMOUTH
ROAD
ANN
ARBOR,
MICHIGAN
48105­
2498
MEMORANDUM
March
3,
2006
Subject:
Estimated
Number
of
Refueling
Events
for
Residential
Mowing
Equipment
From:
Phil
Carlson,
Engineer
//
Signed//
Nonroad
Center
To:
Docket
EPA­
OAR­
2004­
0008
In
an
effort
to
estimate
the
number
of
refueling
events
associated
with
residential
mowing
equipment,
EPA
pulled
information
on
equipment
activity
from
the
NONROAD
model.
The
NONROAD
model
is
EPA's
model
for
estimating
emissions
from
most
categories
of
nonroad
equipment,
including
lawn
and
garden
equipment.
The
following
table
includes
the
estimated
population
and
associated
activity
from
the
NONROAD
model
for
the
three
residential
applications
used
for
mowing
grass.
(
The
numbers
presented
in
the
table
do
not
include
equipment
in
California,
which
sets
its
own
emission
standards
for
nonroad
engines.)

Residential
Mowing
Equipment
Population
and
Activity
Based
on
EPA's
NONROAD
Model
Application
Estimated
2005
Population
(
49­
state,
excludes
California)
Associated
Annual
Activity
(
hours)
Residential
Walk
Behind
Mowers
34,985,448
874,636,202
Residential
Lawn
and
Garden
Tractors
12,728,882
572,799,672
Rear
Engine
Riding
Mowers
1,862,666
67,055,975
Total
for
Residential
Mowing
Equipment
49,576,996
1,514,491,849
In
general,
EPA
believes
that
a
tank
of
gas
on
residential
mowing
equipment
will
provide
roughly
one
hour
of
operation.
As
a
result,
the
number
of
refueling
events
associated
with
residential
mowing
equipment
will
be
roughly
equivalent
to
the
total
activity
(
in
hours)
of
residential
mowing
equipment.
Therefore,
EPA
estimates
there
were
roughly
1.5
billion
refueling
events
associated
with
residential
mowing
equipment
for
the
2005
calendar
year.
