By Brett Rosenberg
May 24, 2004

In a multi-faceted approach to reduce the amounts of dangerous air pollutants entering the atmosphere, the U.S. Environmental Protection Agency announced on May 11 its new Clean Air Nonroad Diesel Rule. The rule requires new construction and agricultural equipment, industrial equipment such as airport service vehicles, and utility equipment such as pumps and generators to meet strict emissions standards. Once the new rule is implemented, the EPA estimates a 90 percent reduction in emissions of ozone-forming nitrogen oxides (NOx) and the fine particulates matter that form smog.

According to the EPA, 474 counties are currently out of attainment of new ozone standards, threatening the health of 160 million people.

The new rule also contains provisions that aim to reduce diesel fuel sulfur content by 99 percent. This will facilitate advances in cleaner engine technologies and helps further reduce particulate matter and acid rain. Diesel fuel for nonroad vehicles currently contains about 3,000 parts per million (ppm) of sulfur. The new rule will reduce that to 500 ppm in 2007 and 15 ppm by 2010.

The Clean Air Nonroad Diesel Rule covers the 650,000 pieces of nonroad diesel equipment sold in the U.S. annually. The EPA estimates there are currently over six million pieces of nonroad diesel equipment in use. Based on average equipment life expectancies, the entire inventory should be entirely upgraded by 2030.

According to the EPA, the new standards, which will be phased in over the next several years, will have the air quality benefits of removing two million trucks from the nation's roads. Existing mobile sources covered by the new Clean Air Nonroad Diesel Rule currently account for 45 percent of particulate matter entering the atmosphere in this country and 25 percent of the nitrogen oxides. The projected 90 percent reduction in emissions will include 129,000 tons of particulate matter and 738,000 tons of NOx annually.

As new engines are phased in and the low'sulfur fuel requirement is implemented, the EPA anticipates significant public health benefits. By 2030, the time when the EPA expects the entire inventory of non-road diesel engines to be fully upgraded, controlling particulate matter and NOx pollution will annually prevent 12,000 premature deaths, 8,900 hospitalizations and one million lost work days.

Cost estimates of the new rule vary, based on the size and complexity of the equipment. They range from one to three percent of the total purchase price for most nonroad diesel equipment, according to the EPA. The EPA further estimates that the added cost for low'sulfur fuel is about seven cents per gallon. Once ultra-low sulfur fuel becomes available, engine maintenance expenses will decrease accordingly, resulting in a net cost of about four cents per gallon. The EPA estimates the overall benefits of the nonroad diesel program, including reduced maintenance expenses and realized health benefits, outweigh the costs by a ratio of 40 to 1.

EPA will phase in the new engine standards in 2008, beginning with the smallest new engines. Over the following six years, new NOx and particulate matter standards will apply to all but the largest diesel engines. These engines, used in very heavy duty equipment such as in the mining industry, with over 750 horsepower, will have an additional year to meet the new standards. Although benefits from the new engine requirements will take time due to the phase-in requirements, air quality and public health will realize immediate benefits once the low sulfur requirements kick in.

The Clean Air Nonroad Diesel Rule is one part of the EPA's Clean Diesel Program and part of a suite of recently announced strategies to reduce air pollution nationwide, known as the Clean Air Rules of 2004. In 2000, the EPA finalized a similar rule that applies to heavy-duty trucks and buses.