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Regulatory

Announcement

 Printed on Recycled Paper

United States

Environmental Protection

Agency

Air and Radiation EPA420-F-97-049

December 1997

Office of Mobile Sources

Environmental Benefits of Emission

Standards for Locomotives

The Environmental Protection Agency (EPA) has established emission

standards for oxides of nitrogen (NOx), hydrocarbons (HC), carbon

monoxide (CO), particulate matter (PM) and smoke for newly manufactured and remanufactured locomotives and locomotive engines, which

have previously been unregulated. The new standards will achieve

approximately a two-third reduction in NOx emissions, which is equivalent to removing over thirty million passenger cars from the road. In

addition, HC and PM emissions will be reduced by 50 percent.

Overview of Rulemaking

EPA has finalized emission standards for locomotives that will provide

significant emission reductions, beginning in the year 2000, to help states

comply with National Ambient Air Quality Standards (NAAQS) for

ozone and PM. Since locomotive emissions have not been regulated

before, it was necessary for EPA to create a comprehensive program,

including not only emission standards, but also test procedures and a full

compliance program. There are three separate sets of emission standards,

with applicability of the standards dependent on the date a locomotive is

first manufactured. The first set of standards (Tier 0) apply to locomotives and locomotive engines originally manufactured from 1973 through

2001, any time they are remanufactured in calendar year 2000 or later.

The second and third sets of standards (Tier 1 and Tier 2) apply to locomotives and locomotive engines originally manufactured on or after
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January 1, 2002 (Tier 2 standards will take effect on January 1, 2005).

These locomotives and locomotive engines will also be required to meet

the same standards at each subsequent remanufacture. The Agency has

also established a rigorous emission testing program to make sure that

locomotives comply with these standards for the life of the locomotive.

Health and Environmental Concerns

Most locomotives in the U.S. are powered by diesel engines. Thus

locomotives have significant NOx emissions, as well as HC and PM

emissions, all of which have significant health and environmental effects. NOx is a major component of smog and acid rain. NOx emissions

combine with HC in the atmosphere to form ground-level ozone, the

primary constituent of smog. Ozone is a highly reactive pollutant that

damages lung tissue, causes congestion, and reduces vital lung capacity,

in addition to damaging vegetation. Acid rain damages buildings and

crops, and degrades lakes and streams. NOx also contributes to the

formation of secondary PM, which causes headaches, eye and nasal

irritation, chest pain, and lung inflammation. Environmental impacts of

PM include reduced visibility and deterioration of buildings.

Locomotive Emission Inventories

Locomotive NOx emissions are estimated to represent about 5.5 percent

of NOx emissions from all mobile and stationary sources in the U.S.

Locomotive PM and HC emissions are both estimated to represent less

than one-quarter of one percent of total national emissions. Thus, the

focus of EPA’s regulation was on NOx emission reductions. It should be

noted that in some urban areas that have very high rail traffic, such as

Chicago or El Paso, NOx emissions can represent about one-tenth of the

total NOx inventory.

Current National Locomotive Emission Inventories

Pollutant Metric Tons Per

Year

Percent of Total

Inventory

(All Sources)

N 0 Ox 1 5 ,093,00 5.

P 0 M-10 2 1 7,00 0.

H 0 C 4 2 2,00 0.
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Environmental Benefits of New Standards

When fully phased-in, the new emission standards will reduce NOx

emissions from locomotives by nearly two-thirds, and HC and PM

emissions by half. They will also achieve very significant emission

reductions in the near term, however. These reductions, which are shown

below, are being heavily relied upon by those areas that have very high

rail traffic, as well as Southern California, which has moderately high

rail traffic and very significant air quality needs. To put these national

NOx emission reductions into context, the 304,000 ton per year reduction expected in 2005 would be equivalent to removing nearly 20 million passenger cars from the road. In addition, NOx emission reductions

will also lead to reductions in ambient concentrations of secondary PM.

It has been estimated that about 4 tons of nitrate particulate is formed

from every 100 tons of NOx emitted. Thus, the secondary PM reduction

expected in 2005 is about 12,000 tons per year.

* Assumes 4 tons of nitrate particulate formed for each 100 tons of NOx emitted.

Reductions from Existing Locomotive Fleet

Much of the expected reduction in NOx emissions will come early in the

program due to the Tier 0 standards that apply to existing locomotives

when they are remanufactured. These standards are a unique feature of

this regulation, and represent the first time that EPA has regulated the

remanufacturing of an existing fleet on such a large scale. Such regulation of the remanufacturing process is critical because locomotives are

generally remanufactured five to ten times during their total service lives

(typically 40 years or more). Standards that would only apply to locoProjected National Emission Reductions (Metric Tons)

Pollutant

Year

2 0 005 2 5 01 2 0 01 202

N 0 Ox 3 0 04,00 4 0 49,00 4 0 96,00 538,00

P 0 M 9 0 0 4 0 ,40 6 0 ,00 7,60

H 0 C 1 0 ,40 6 0 ,30 8 0 ,70 11,00

Secondary

PM* 1 0 2,000 1 0 8,00 2 0 0,00 21,00
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motives originally manufactured after the effective date of the rule would

not achieve significant emissions reductions until those future locomotives replaced a significant number locomotives in the existing fleet. For

the first 10 years of the program, the majority of projected NOx emission

reductions will be the result of the Tier 0 emission standards that apply to

existing locomotives.

For More Information

The final rule and other documents on locomotives are available electronically from the EPA Internet server at:

http://www.epa.gov/OMSWWW/locomotv.htm

Document information is also available by contacting Russ Banush at:

U.S. Environmental Protection Agency

2565 Plymouth Road

Ann Arbor, MI 48105

(734) 668-4333.