United States             Air and Radiation         EPA420-F-98-044
                   Environmental Protection                          November 1998

                   Office of Mobile Sources
&EPA        Regulatory
                    Proposed Emission Standards for
                    New Cl  Marine Engines
                   The U.S. Environmental Protection Agency (EPA) is issuing a Notice of
                   Proposed Rulemaking (NPRM) for emissions from new compression-
                   ignition (Cl) marine engines rated over 37 kilowatts (50 horsepower).
                   Control of emissions from this currently unregulated source will help
                   reduce the harmful health effects of ozone and particulate matter from
                   nonroad engine sources.
                   A National Emission Control Program

                   EPA is proposing a national program to control emissions of oxides of
                   nitrogen (NOx) and particulate matter (PM) from large marine diesel
                   engines. These engines are used for propulsion and auxiliary power on
                   commercial vessels in a variety of marine applications, including fishing
                   boats, tug and towboats, dredgers, coastal and Great Lakes cargo ves-
                   sels, and ocean going vessels. Engines for recreational vessels will be
                   covered by a subsequent rulemaking action.

                   The results of a 1990 EPA study demonstrated the need for control of air
                   pollution in the nonroad engine and vehicle arena. EPA published this
                   finding in conjunction with the first rulemaking to set emission stan-
                   dards for nonroad engines, which was completed in June 1994. In April
                   1998, the Agency issued final requirements for emission controls for
                   locomotive engines. In September 1998, the Agency issued final re-
                   quirements for more stringent emission standards for diesel engines
                   used in most nonroad applications, including marine engines below 37
                                                            > Printed on Recycled Paper

Emissions from marine diesei engines account for about 4.5 percent of
total mobile source NOx emissions nationwide and about 1 percent of
PM emissions. However, because of the nature of their operation, the
contribution of these engines to total NOx emissions in port cities and
coastal areas is higher. This NPRM supplements these actions by propos-
ing a comprehensive emission control program for the marine derivatives
of these land-based engines. It also follows an Advance Notice of Pro-
posed Rulemaking (ANPRM) published in the Federal Register on May
22, 1998, that described the background and general provisions the
Agency was considering for marine diesei engine emission controls.
Highlights of

This NPRM proposes three important sets of provisions. First, it sets out
a two-phase emission control strategy for marine diesei engines that are
derived from, or use the same technologies as, land-based nonroad or
locomotive engines. The first phase would go into effect in 2004 or 2006,
depending on engine size. The
second phase would go into
effect in 2008 or 2010, but will
be subject to a feasibility
review in 2003.  Larger engines
would be required to meet the
emission limits finalized by
the International Maritime
Organization (IMO). The IMO
limits would also apply to the
smaller engines prior to 2004.

Second, the NPRM proposes a new approach for controlling off-cycle
emissions, and calls for engine manufacturers to demonstrate compliance
with the emission limits over a variety of operating conditions. These off-
cycle requirements would become effective with the 2004/2006 emission
limits. Finally, the certification and compliance provisions being consid-
ered are derived from the programs for land-based nonroad or locomotive
engines, but will reflect unique characteristics of the marine derivatives
of these engines.

If the emission standards and other requirements are implemented as
discussed in the proposed rule, EPA would expect to see a 34 percent
reduction in NOx emissions and a 14 percent reduction in PM emissions
in 2030 when the program is fully phased-in. Overall, the program
would provide much-needed assistance to states facing ozone and
particulate air quality problems that are causing a range of adverse
health effects for their citizens,  especially in terms of respiratory impair-
ment and related illnesses.
EPA desires full public participation in arriving at rulemaking decisions.
The Agency solicits comments from all interested parties. Wherever
applicable, full supporting data and detailed analysis should also be
submitted to allow EPA to make maximum use of the comments. Com-
menters are especially encouraged to provide specific suggestions for
changes to any aspects of the proposal that they believe need to be
modified or improved.

EPA will hold a pubic hearing in January 1999 and will accept written
comments on the NPRM for 60 days after publication in the Federal
Register, expected in December 1998. For instructions on submitting
written comments, please see the Federal Register notice. It is available
from the EPA Air and Radiation Docket by calling 202-260-7548; please
refer to Docket No. A-97-50. In addition, the ANPRM and related
documents are available electronically via the EPA Internet server at:

Additional documents on marine engines are available electronically at
the Internet site given above, or by contacting:

CI Marine Team
U.S. Environmental Protection Agency
Office of Mobile Sources
2000 Traverwood
Ann Arbor, Michigan 48105