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Regulatory

Announcement

 Printed on Recycled Paper

United States

Environmental Protection

Agency

Air and Radiation EPA420-F-02-004

April 2002

Office of Transportation and Air Quality

Emission Standards for

New Marine Diesel Engines

Relationship Between EPA's Control

Program and MARPOL Annex VI

The U.S. Environmental Protection Agency (EPA) is proposing emission

standards for large marine diesel engines used on ocean-going vessels.

These emission standards, along with EPA’s other emission standards

for smaller marine diesel engines, are separate from but are

comparable to emission standards adopted by the International

Maritime Organization (IMO) in Annex VI to the International Convention

on the Prevention of Pollution from Ships. This fact sheet summarizes

the main provisions of these two regulatory programs and describes

how the two programs fit together.

What is MARPOL Annex VI?

The IMO, which was set up in 1948 under the United Nations to address

safety, navigation, and pollution prevention for ships engaged in international trade, was responsible for drafting MARPOL: the International

Convention on the Prevention of Pollution from Ships, 1973, as Modified by the Protocol of 1978 Relating Thereto. There are six annexes that

address different kinds of pollution from ships: oil, noxious substances,
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garbage, sewage, and air emissions. Annex VI addresses air emissions:

ozone depleting substances, incinerators, and emissions from tanker

operations, as well as NOx (oxides of nitrogen) and SOx (oxides of

sulfur) emissions from ship engines. Although Annex VI was adopted by

the IMO in 1997, it will not go into force internationally until 15 countries representing 50 percent of world merchant tonnage ratify it. So far,

six countries representing 16 percent have ratified it.

What is the status of U.S. ratification of Annex VI?

The U.S. government is preparing the appropriate documents for the

President to submit Annex VI to the Senate for its advice and consent to

ratification. In transmitting Annex VI to the Senate, the Administration

will work with Congress on new legislation to implement the Annex. At

the same time, the United States government supports a revision of the

Annex VI standards for NOx emissions, taking into account the emission

reduction potential of new control technologies. By ratifying the Annex,

the United States will continue to promote environmentally responsible

international emission standards at the IMO and recognize the role the

IMO plays in protecting the world’s marine environment from pollution.

The U.S. government has already requested the Marine Environment

Protection Committee of the IMO to begin consideration of more stringent NOx emission limits for marine diesel engines. Once the Annex

goes into force, amendment of NOx standards will be made easier

through the tacit amendment process that would then apply.

What is the EPA program for marine diesel engines?

EPA has set marine diesel engine standards under Section 213 of the

Clean Air Act, which directs EPA to set emission standards for classes or

categories of new nonroad engines and vehicles. The standards are to

achieve the greatest degree of emission reduction achievable through the

use of technology that is expected to be available when the emission

limits go into effect, taking into account the cost of the technology and

noise, energy, safety factors, and lead time.

EPA set standards for marine diesel engines below 30 liters per cylinder

in 1999. The Tier 1 standards are equivalent to the Annex VI limits for

these engines and are voluntary until the Tier 2 standards go into effect.

The Tier 2 standards, which phase in between 2004 and 2007, reflect

additional reductions that can be achieved through engine-based controls. These standards apply only to engines on US-flag vessels.
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We are now proposing standards for marine diesel engines at or above 30

liters per cylinder. The Tier 1 standards are equivalent to the Annex VI

NOx limits for these engines, for engines built in 2004 and later. We are

considering a second tier of standards that would reflect additional

reductions that can be achieved through engine-based controls and would

apply to new engines built after 2006 or later. The proposed standards

would apply only to engines on US-flag vessels; we are seeking comment on applying them to engines on foreign flag vessels as well.

What is the relationship between MARPOL and EPA

programs?

In general, MARPOL does not prevent a country from setting standards

for its ships. Annex VI specifically allows a country to set alternative

standards that would apply to engines on ships that operate solely in

waters under its jurisdiction. To meet its obligations under the Clean Air

Act to set standards for these engines, the U.S. is exercising these

MARPOL provisions. Because engines on these vessels will be subject

to both programs, it is important to understand the relationship between

them. Ship owners and operators as well as engine manufacturers should

be familiar with these two programs because each program has requirements for both groups.

What would be the most significant differences

between the two programs?

We require that the engine manufacturer be responsible for ensuring

compliance with the emission standards for the full useful life of the

engine, while the Annex VI program makes the ship operators fully

responsible for ensuring in-use compliance.

We require that the engine manufacturer demonstrate prior to

production that they comply with the emission standards for the full

useful life of the engine. The Annex VI program would only require

that the manufacturer demonstrate that the engine meets the standards when it is installed in the vessel; there is no Annex VI durability demonstration.

We allow, but do not require, witness testing for U.S. compliance.

Liability for

in-use

compliance

Durability

demonstration

Witness

testing
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We are proposing to certify Category 3 marine engines using the

Annex VI test procedures for diesel marine engines with modification. The modifications are required to ensure that the test data used

for certification are representative of in-use operation. We expect

that manufacturers would be able to use data from certification tests

conducted according to the modified EPA procedures for Annex VI

certification.

We are proposing that the official test fuel specification for C3

engines be a residual fuel. Annex VI specifies using distillate test

fuels and uses distillate testing as the basis of its standards. We are

proposing to allow certification testing on marine distillate fuel to

be consistent with Annex VI. However, we would correct the NOx

emissions, based on fuel nitrogen content, before the test results are

compared to our residual fuel based standards.

We are proposing to apply the standards based on the date of final

assembly of the engine, while Annex VI generally applies the

standards based on the start-date of the manufacture of the vessel.

We are proposing a simple production testing program to ensure

that certification designs would be translated into production engines that meet applicable standards. Annex VI also requires verification that engines are properly installed, but allows this to be

demonstrated by either a parameter check or by testing.

Annex VI requires that engine manufacturers provide operators

with a Technical File that contains maintenance instructions, test

data, and other compliance information. We are proposing only to

require the manufacturer to provide maintenance instructions

necessary to ensure that the engine would continue to meet the

emission standards in use.

To ensure that an engine in-use continues to meet the standards, we

are proposing that operators be required to perform a simple field

measurement test to confirm emissions after a parameter adjustment

or maintenance operation. The Annex VI program would require

only periodic surveys of the engine, which can take the form of a

simplified onboard test or, more frequently, a parameter check.

Test

procedures

Test fuel

Compliance

date for

standards

Production

testing

Technical

file

In-use

compliance
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We are proposing to allow manufacturers to specify in their applications for certification the range of adjustment across which the

engine is certified to comply with the applicable emission standards.

Operators would be prohibited by the anti-tampering provisions

from adjusting engines to a calibration different from the calibration

specified by the manufacturer when they are within 175 miles of the

U.S. coast. We are also proposing to require all new Category 3

engines be equipped with emission measurement systems and with

automatic electronic-logging equipment that automatically records

all adjustments to the engine and the results of the required verification tests. Annex VI would prohibit operators from adjusting engines to a calibration different from the calibration specified by the

manufacturer under any circumstances.

We are proposing that simplified onboard measurements be used to

confirm proper adjustment of in-use engines. Annex VI allows such

systems, but does not require them.

Could a manufacturer comply with both the EPA

requirements and the Annex VI requirements at the

same time?

A manufacturer that complied with the proposed EPA requirements

would need to do very little additional work to meet the Annex VI

requirements. First, the engine manufacturer would need to provide the

operator with a Technical File that contains more information than would

be required by EPA. The manufacturer may also need to ensure that the

relevant emission testing is witnessed appropriately.

For manufacturers that have already complied with the Annex VI, the

amount of additional work that would be required to comply with the

proposed EPA requirements would be dependent on how the manufacturer conducted its emission testing. Additional requirements include:

• Demonstrate prior to production that the engines would comply with

the emission standards for the useful life of the engine.

• Warrant to the purchasers that the engines would comply with the EPA

requirements for the useful life of the engine.

• Perform a simple production test after installation.

Parameter

adjustment

Onboard

measurement
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• Install an onboard measurement system.

• Specify how the operator should adjust the engine in use and how

proper adjustment should be verified through testing.

How can I obtain additional information about these

programs?

You can find additional information about the EPA marine diesel engine

program at www.epa.gov/otaq/marine.htm.

You can find additional information about the IMO program on the IMO

Web site at www.imo.org. Please note that the IMO does not provide

copies of its programs on its Web site. You may obtain a copy from your

local library, or purchase a copy of Annex VI of MARPOL 73/78: Regulations for the Prevention of Air Pollution from Ships and NOx Technical

Code from the IMO (ISBN 92-801-6089-3) (IMO Sales Number IMO664E).