United States              Air and Radiation           EPA420-F-96-016
                   Environmental Protection                            February 1997

                   Office of Mobile Sources
&EPA      Environmental
                   Fact Sheet
                   Summary of EPA's Nonroad Engine
                   Control Programs
                   In response to environmental and public health concerns, the U.S.
                   Environmental Protection Agency (EPA) is establishing emission standards
                   for a number of nonroad engine categories. The categories of nonroad
                   engines currently being addressed by EPA cover a variety of applications
                   including farm and construction equipment, lawn and garden equipment,
                   marine vessels, and locomotives, Asa whole, EPA's nonroad programs
                   will significantly reduce the impact of nonroad equipment on the nation's air
                   EPA has been regulating on-highway cars and trucks since the early 1970s
                   and has continued to set increasingly stringent standards for such vehicles.
                   Because much progress has been made in controlling the emissions from on-
                   highway vehicles, EPA has begun turning its attention to nonroad categories
                   of mobile sources which also contribute significantly to air pollution.  These
                   nonroad control programs will assist states in complying with the National
                   Ambient Air Quality Standards (NAAQS).

                   The 1990 Clean Air Act Amendments specifically direct EPA to study the
                   contribution of nonroad engines to urban air pollution, and regulate them if
                   warranted. "Nonroad" is a term that covers a diverse collection of engines,
                   equipment, and vehicles. Also referred to as "off-road" or "off-highway,"
                   the nonroad category includes outdoor power equipment, recreational
                   equipment, farm equipment, construction equipment, lawn and garden
                              Recycled/Recyclable  Printed with Vegetable Oil Based inks on 100% Recycled Paper (20% Postconsumer)

  equipment, and marine vessels.  Although
  dealt with separately hi the Clean Air Act,
  locomotives and aircraft can also be
  considered nonroad categories of equip-
  ment. Except for aircraft, all categories of
  nonroad equipment were unregulated by
  EPA prior to the mid-1990s.
        1994 Nonroad NOx Emissions Inventory
Sourc*: EPA Trends Report, 10/95
                           Note: 1% = 31,000 tons
(Recreational Equipment Is
<0.1% of inventory)
  In 1991, EPA released a study that docu-
  mented higher than expected emission
  levels across a broad spectrum of nonroad
  equipment. The EPA study showed that
  emissions from the various nonroad cat-
  egories are a significant source of oxides
  of nitrogen (NOx), volatile organic com-
  pound (VOC) and particulate matter (PM)
  emissions. In some areas of the country,
  emissions from nonroad engines represent
  a third of the total mobile source NOx and
  VOC inventory and over two-thirds of the
  mobile source PM inventory.

  In response, EPA has initiated regulatory
  programs for several categories of nonroad
  engines.  The following sections summa-
  rize the status of EPA's regulatory pro-
  grams for the various nonroad equipment
Compression-Ignition Engines
Compression-ignition (CI) engines (i.e.,
diesel-fueled engines) dominate the large
nonroad engine market and comprise
approximately 20 percent of the current
mobile source NOx emissions inventory
and 45 percent of the current mobile source
PM emissions inventory. Examples of
equipment that would fall into this cat-
egory include agricultural equipment such
as tractors, construction equipment such as
backhoes, materials handling equipment
such as forklifts, and utility equipment
such as generators and pumps.

Under EPA regulations, CI engines greater
than 50 horsepower (hp) must comply with
Tier 1 emissions standards that are being
phased in between 1996 and 2000 depend-
ing on the size of the engine. The Tier 1
standards apply to all CI engines greater
than 50 hp except for those used in under-
ground mining equipment, locomotives,
and marine vessels.  (The Mining Safety
and Health Administration is responsible
for setting requirements for underground
mining equipment. Locomotives and
marine vessels are covered by separate
EPA programs, as described below.)
Under the Tier 1 standards, EPA projects
that NOx emissions from new CI nonroad
equipment will be reduced by over 30
percent from the uncontrolled levels of
unregulated engines.

In September 1996, EPA, the California
Air Resources Board (GARB), and the
manufacturers of CI nonroad engines
signed a "Statement of Principles" that is
expected to lead to the adoption of tighter
NOx plus hydrocarbon (HC) and PM
emission standards for all CI nonroad

engines manufactured after 1999 (exclud-
ing those engines used in underground
mining equipment, locomotives, and
marine vessels over 50 hp). This agree-
ment will lead to the first set of standards
for CI engines less than 50 hp, and further
controls for engines greater than 50 hp.

EPA issued an Advance Notice of Pro-
posed Rulemaking (ANPRM) in January
1997 that contained the text of the CI
engine Statement of Principles and re-
quested public comment on the agreement.
EPA expects to issue a Notice of Proposed
Rulemaking (NPRM) for CI  engines to
formally propose the new emission  stan-
dards contained in the Statement of Prin-
ciples in mid 1997. Under the standards
contained in the Statement of Principles,
EPA projects that emissions from new CI
nonroad equipment would be further
reduced by 60 percent for NOx and 40
percent for PM compared to  the emission
levels of engines meeting the Tier 1 stan-
      Examples of Affected C.I.
           agricultural tractors
 Spark-Ignition Engines
 Small spark-ignition (SI) engines (e.g.,
 gasoline, natural gas, propane or methanol
 fueled engines) at or below 25 hp (19
kilowatts) comprise about 9 percent of the
mobile source VOC inventory.  These small
engines are used primarily in lawn and
garden equipment, such as lawnmowers,
string trimmers, edgers, chain saws, com-
mercial turf equipment, and lawn and
garden tractors. Under Phase 1 of EPA's
regulations, new small SI engines must
comply with emission standards beginning
in 1997.  The Phase 1 standards apply to all
SI engines at or below 25 hp except for
those used in underground mining equip-
ment, aircraft, marine vessels, and recre-
ational equipment. EPA expects that these
Phase 1 standards will result in a 32 per-
cent reduction in  HC emissions from small
SI engines.

Phase 2 regulations addressing emissions
from these engines are currently under
development. In May 1996, EPA and f Ave
other parties signed a Statement of Prin-
ciples which will form the basis of the
Phase 2 proposal for new small SI engines
used in handheld applications.  In Decem-
ber of 1996, EPA and engine manufacturers
signed a Statement of Principles for small
SI engines used in nonhandheld applica-
tions that will form the basis of the Phase 2
proposal for such engines. EPA plans to
issue an ANPRM which will contain the
text of both small SI engine Statement of
Principles for public review and comment
in early 1997.  EPA will then issue a
NPRM covering both handheld and
nonhandheld small SI engines in late  1997.
EPA expects the Phase 2 program to reduce
combined emissions of HC plus NOx from
these engines by  an additional 30 to 40
percent beyond Phase 1 levels.

SI engines above 25 hp are currently not
regulated by EPA, except for those used in
marine applications.  In the Statement of
Principles signed with the CI engine
manufacturers referenced earlier, EPA and
CARS noted that they intend to work with
the SI nonroad engine industry to develop
a Statement of Principles for SI nonroad
engines above 25 hp that would establish
the framework of a control program for the
larger SI engines.
       Examples of Affected S.I.
              lawn mowers
              lawn tractors
              leaf blowers
Marine Vessels
Marine vessels encompass a wide range of
equipment, including everything from
small outboard engines and personal
watercraft, to tugboats and large oceango-
ing vessels.  EPA is developing emissions
control programs for both gasoline and
diesel marine engines.

Recreational gasoline marine includes
outboard engines, personal watercraft
engines, jet boat engines, and sterndrive
and inboard (SD/I) engines.  Recreational
gasoline marine engines contribute about 5
percent of the national mobile source VOC
inventory. In areas with large boat popula-
tions, however, the contribution of recre-
ational marine engines may be in excess of
10 percent of the total HC inventory.

EPA finalized regulations for the control of
exhaust emissions from new SI, gasoline-
fueled marine engines (the type typically
used in recreational marine vessels) in July
1996. The regulations apply to outboards
and personal watercraft, including jetboat
engines, which typically employ simple 2-
stroke technology (that has not changed in
over 50 years) and emit very high rates of
HC exhaust emissions.  EPA is not finaliz-
ing emission standards for SD/I engines at
this time.

The program requires increasingly strin-
gent HC control over the course of a nine-
year phase-in period beginning in model
year 1998. By the end of the phase-in,
each manufacturer must meet an HC plus
NOx emission standard, on a corporate
average basis, that represents a 75 percent
reduction in HC compared to unregulated
levels. The emission standard allows the
manufacturers and the market to determine
the best approach to achieving the targeted
reductions over time by allowing them to
phase in the types of control technologies
to keep the cost increase as low as possible
for boaters. Compliance with a corporate
average emission standard gives manufac-
turers the flexibility to build engines below
and above the emission standard, provided
the manufacturer's overall corporate aver-
age is at or below the new standard.

CI diesel-fueled marine engines are a
diverse nonroad category that includes
small auxiliary and propulsion engines,

medium-sized propulsion engines on
coastal and harbor vessels, and very large
propulsion engines on ocean-going vessels.
The contribution of this source to the
average national mobile source NOx
inventory is approximately 2.5 percent,
although the contribution is much greater
in areas with commercial ports.  Emissions
from diesel marine engines are virtually
unregulated at this time.  This will change
in the near future, as a result of regulatory
efforts at international and national levels.

At the international level, emissions from
marine vessels will be regulated by Annex
VI of the International Convention on the
Prevention of Pollution from Ships
(MARPOL). The International Maritime
Organization has been working on NOx
emission standards from these vessels to be
finalized in September 1997.  The stan-
dards will achieve a 30 percent reduction
over uncontrolled levels, and will apply
beginning January 1, 2000 to all engines
on all vessels used in international voy-
ages, as well as large engines used on
marine vessels that operate only domesti-
cally. On the national level, the smaller
domestic vessels not covered by MARPOL
will be subject to a new set of CI marine
engine regulations currently being devel-
oped by EPA.
 Currently unregulated by EPA, locomo-
 tives are estimated to contribute about 9
 percent of the nationwide mobile source
 NOx emissions inventory, making locomo-
 tives one of the largest remaining unregu-
 lated sources of NOx emissions. As
 directed by the Clean Air Act, EPA is
 developing emission standards for locomo-
 tives to assist states in complying with the
 NAAQS for ozone and PM. Because
 locomotive emissions have not been
 regulated before, EPA must create a com-
 prehensive program, including not only
 emission standards, but also test proce-
 dures and a full compliance program.

 One unique feature expected to be included
 for locomotives is the regulation of the
 engine remanufacturing process, including
 the remanufacture of locomotives origi-
 nally built prior to the effective date of this
 rulemaking. Regulation of the
 remanufacturing process is critical because
 locomotives are generally remanufactured
 5 to 10 times during their total service lives
 (typically 40 years or more).
       1994 Nonroad VOC Emissions Inventory
 Source: EPA Trends Report, 10/95
  EPA plans to publish the locomotive
  NPRM in early 1997 and expects that it
  would take effect in 2000. When fully
  phased-in, EPA expects the new standards
  will achieve a reduction in NOx emissions
  of more than 60 percent from uncontrolled
  levels. Standards are also being considered
  that would reduce PM emissions from
  locomotives by 50 percent.

 Aircraft emissions comprise less than 2
 percent of the mobile source NOx emis-
 sions inventory, but they are significant
 contributors to the NOx inventory in some
 cities. In addition, aircraft emissions are
 potentially important contributors  to global
 climate change and may also contribute to
 the depletion of the stratospheric ozone
       1994 Nonroad PM-10 Emissions Inventory
                                  Cl Engines
 SI Englnci
Scant. EPA Trends Report, 10/95
                              Note: 1% = 4,000
 Emission standards for gas turbine engines
 that power civil aircraft have been in place
 for about 20 years. Such engines are used
 in essentially all commercial aircraft
 including scheduled and freight airlines.
 (Tvvo classes of aircraft, military and
 general aviation, are not covered by stan-

 Controls on engine smoke and prohibitions
 on fuel venting were instituted in 1974 and
 have been revised several times since then.
 Beginning in 1984, limits were placed on
 the amount of unburned HC gas turbine
 engines can emit per landing and takeoff
 cycle. EPA is currently preparing a Direct
 Final Rulemaking (DFRM) to adopt the
 existing International Civil Aviation Orga-
 nization (ICAO) NOx and carbon monox-
 ide (CO) emission standards for gas turbine
 engines. ICAO is the most appropriate
 forum for first establishing commercial
 aircraft engine emission standards due to
 the international nature of the aviation
 industry. EPA expects to issue the aircraft
 DFRM in early 1997.

 EPA has also explored other ways to
 reduce the environmental effects associated
 with air travel throughout the nation.
 Along with the Federal Aviation Adminis-
 tration (FAA), EPA is working to encour-
 age continuing progress in reducing emis-
 sions from airport ground service equip-
 ment and aircraft auxiliary power units.
 EPA has sponsored compilation of techni-
 cal data and emission inventory methods
 which will be used by the FAA to develop
 an Advisory Circular for airlines and
 airport authorities interested in reducing
 emissions from these sources.
Recreational Equipment
One category of nonroad engines not
subject to regulation by EPA at this time is
recreational nonroad equipment such as go-
carts, all-terrain vehicles, and snowmo-
biles. (As noted earlier, recreational
marine engines are included under EPA's
gasoline-fueled marine regulations.) In the
future, EPA plans to study whether controls
for such nonroad equipment are appropri-
ate and proceed as necessary.

For More Information
For more information on EPA's control
program for nonroad engines and other
mobile sources, please contact the Office
of Mobile Sources by calling 313-668-
4333 or writing to:

  U. S. Environmental Protection Agency
  Engine Programs and Compliance
  2565 Plymouth Road
  Ann Arbor, Michigan 48105

The Office of Mobile Sources also has
information available on the EPA Internet
server and via dial-up modem on the
Technology Transfer Network (TTN), an
electronic bulletin board system (BBS).

  World Wide Web: http://www.epa.gov/

  TTN BBS: 919-541-5742 (1200-14400
  bps, no parity, 8 data bits, 1 stop bit);
  voice helpline: 919-541-5384.
Additional Fact Sheets
EPA has additional fact sheets that go into
more detail on these nonroad engine
control programs:

Nonroad Engines and Air Pollution
(EPA420-F-94-003), May 1996.

Control of Emissions from Nonroad En-
gines (EPA420-F-96-009), July 1996.

Statement of Principles for Nonroad Diesel
Engines (EPA420-F-96-015), Septem-
ber 1996.
Statement of Principles for Small Handheld
Gasoline Engines (EPA420-F-96-001),
May 1996.

Statement of Principles for Small
Nonhandheld Spark-Ignited
'Engines (EPA420-F-97-002), January

Emission Standards for New Gasoline
Marine Engines (EPA420-F-96-012),
August 1996.

Emission Standards for New Spark-Ignition
Marine Engines: Information for the
Marine Industry (EPA420-F-96-013),
August 1996.

Boating Pollution Prevention Tips
(EPA420-F-96-003), July 1996.

Reducing Marine Vessel and Port Emis-
sions in the South Coast (EPA420-F-96-
011), July 1996.

Proposed Emission Standards for Locomo-
tives (EPA420-F-97-007), February 1997.

Federal Preemption of State and Local
Control of Locomotives (EPA420-F-97-
008), February 1997.

Environmental Benefits of Proposed Emis-
sion Standards for Locomotives (EPA420-
F-97-009), February 1997.

Locomotive Emission Standards (EPA420-
F-96-008), July 1996.

Reducing Aircraft and Airport Emissions in
the South Coast (EPA420-F-96-010),
July 1996.
'U.S. Government Printing Office: 1997 517-416

United States
Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, Ml 48105
Official Business
Penalty for Private Use