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Regulatory

Announcement

Office of Transportation

and Air quality

EPA420-F-04-032

May 2004

Clean Air Nonroad Diesel Rule

On May 11, 2004, the U.S. Environmental Protection Agency (EPA)

announced a comprehensive rule to reduce emissions from nonroad

diesel engines by integrating engine and fuel controls as a system to

gain the greatest emission reductions. Engine manufacturers will

produce engines with advanced emission-control technologies similar to

those upcoming for highway trucks and buses. Exhaust emissions from

these engines will decrease by more than 90 percent.

Closely linked to these engine provisions are new fuel requirements that

will decrease the allowable levels of sulfur in fuel used in nonroad diesel

engines, locomotives, and marine vessels by more than 99 percent.

These fuel improvements will create immediate and significant

environmental and public health benefits and will enable the use of new,

high-efficiency emission-control devices on nonroad engines. At the

same time, the Agency is taking the first step toward proposing more

stringent emission standards for engines used in locomotives and

marine vessels.

By greatly reducing diesel emissions, this rule will result in large benefits

to public health that will be even greater than EPA projected at the time

the rule was proposed. These benefits include about 12,000 fewer

premature deaths and hundreds of thousands fewer incidences of

respiratory problems. The overall benefits of the program in dollars

significantly outweigh the costs by a factor of about 40 to 1.

This rule culminates a multi-year collaborative process to reduce

nonroad diesel emissions. EPA worked closely with stakeholders from

industry, state and local governments, environmental and public health

organizations, and others in the design of this program.
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The Need to Reduce Emissions from Nonroad Diesel

Engines

Nonroad diesel engines contribute greatly to air pollution in many of our

nation’s cities and towns. Nonroad engines currently meet relatively

modest emission requirements and therefore continue to emit large

amounts of nitrogen oxides (NOx) and particulate matter (PM), both of

which contribute to serious public health problems. Nonroad diesel

engines that are affected by the new standards currently account for

about 47 percent of diesel PM emissions and about 25 percent of total

NOx emissions from mobile sources nationwide. These proportions are

even higher in some urban areas.

Health Effects

Ozone can aggravate asthma and other respiratory diseases, leading to

more asthma attacks, use of additional medication, and more severe

symptoms that require a doctor’s attention, more visits to the emergency

room, and increased hospitalizations. Ozone can inflame and damage the

lining of the lungs, which may lead to permanent changes in lung tissue,

irreversible reductions in lung function if the inflammation occurs repeatedly over a long time period and may lead to a lower quality of life.

Children, people with heart and lung disease, and the elderly are most at

risk.

Fine particles (PM 2.5) have been associated with an increased risk of

premature mortality, hospital admissions for heart and lung disease, and

increased respiratory symptoms. Long-term exposure to diesel exhaust is

likely to pose a lung cancer hazard. In addition, PM, NOx, and ozone

adversely affect the environment in various ways including visibility

impairment, crop damage, and acid rain.

Description of Nonroad Engines Covered by this

Final Rule

The new emission standards apply to diesel engines used in most construction, agricultural, industrial, and airport equipment. The standards

will take effect for new engines beginning in 2008 and be fully phased in

for most engines by 2014. Larger mobile engines (greater than 750

horsepower) have one year of additional flexibility to meet their emission

standards.
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These emission standards do not apply to diesel engines used in locomotives and marine vessels. However, fuel requirements for these categories are covered in this rule. The Agency is concurrently issuing an

Advance Notice of Proposed Rulemaking announcing the intent to

propose more stringent emission standards for engines used in locomotives and marine vessels.

Exhaust Emission Standards

This rule sets emission standards for different sizes of nonroad engines.

These standards are similar in stringency to the standards adopted for

2007 and later diesel-powered trucks and buses. The rule also includes

new provisions to help ensure that emission-control systems perform as

well when operating in actual use as they do in the laboratory. The

standards are phased-in over several years to provide adequate lead time

to engine and equipment manufacturers. Table 1 shows the new emissions standards.
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Nonroad Diesel Fuel

Just as lead was phased out of gasoline to prevent damage to catalytic

converters, decreasing sulfur levels in nonroad diesel fuel will prevent

damage to the emission-control systems. In addition, reducing sulfur

levels will provide immediate public health benefits by reducing particulate matter from engines in the existing fleet of nonroad equipment,

while reducing engine maintenance cost. This rule will reduce current

sulfur levels from about 3,000 parts per million (ppm) to 15 ppm when

fully implemented (a reduction of greater than 99 percent).

This rule will reduce nonroad diesel fuel sulfur levels in two steps. First,

starting in 2007, fuel sulfur levels in nonroad diesel fuel will be limited

to a maximum of 500 ppm, the same as for current highway diesel fuel.

This limit also covers fuels used in locomotive and marine applications

(though not to the marine residual fuel used by very large engines on

ocean-going vessels).

Second, starting in 2010, fuel sulfur levels in most nonroad diesel fuel

will be reduced to 15 ppm. This ultra-low sulfur fuel will create immediate public health benefits and will make it possible for engine manufacturers to use advanced emission-control systems that will dramatically

reduce both PM and NOx emissions. In the case of locomotive and

marine diesel fuel, this second step will occur in 2012.

Estimated Costs

The cost of producing 15 ppm sulfur for this program is expected to total

seven cents per gallon. Because the use of ultra-low sulfur fuel will

significantly reduce engine maintenance expenses, we estimate that this

net cost will average about four cents per gallon.

The estimated costs for a nonroad equipment manufacturer to comply

with this program vary depending on size and complexity of the equipment. As an example, we estimate that for a typical 175-horsepower

bulldozer, the modifications will cost approximately $2,600, compared to

the overall price of such a bulldozer of approximately $240,000. The

anticipated costs for most categories of nonroad diesel equipment are in

the range of 1-3 percent of the total purchase price.

To reduce the economic impact of meeting new emission standards and

requirements for low sulfur fuels, the final rule includes a number of

flexibility provisions that are primarily aimed at helping small engine

manufacturers and refiners meet the requirements.
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Benefits of the Program

Reducing NOx and PM emissions from nonroad diesel engines by more

than 90 percent will provide a wide range of public health benefits.

Controlling these emissions will, by 2030, prevent every year about:

12,000 premature deaths, 8,900 hospitalizations, one million work days

lost, 15,000 heart attacks, 6,000 children’s asthma-related emergency

room visits, 280,000 cases of respiratory problems in children, 200,000

cases of asthma symptoms in children, and 5.8 million days of restricted

adult activity due to respiratory symptoms.

In dollars, the health benefits of this rule are estimated to be $80 billion

annually once essentially all older engines are replaced. Estimated costs

for the engine and fuel requirements are many times less, amounting to

about $2 billion annually in that time frame. Thus, the cost-benefit ratio

of this program at that time will be approximately 40-to-1.

For More Information

You can access the final rule and related documents on EPA’s web site

at:

www.epa.gov/nonroad-diesel

You can also contact EPA at:

U.S. Environmental Protection Agency

Assessment and Standards Division

2000 Traverwood Drive

Ann Arbor, MI 48105

Voice-mail: (734) 214-4636

E-mail: asdinfo@epa.gov