August 11, 2000

EPA's Heavy-Duty Engine and Diesel Rule

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Heavy-Duty Engine and Vehicle Emission Standards and Highway Diesel Fuel Sulfur Control Requirements

Stated Purpose:

"Protect the public health and the environment of all Americans by reducing the sulfur content in diesel fuel by 97 percent to provide for the cleanest-running heavy-duty trucks and buses in history."

Summary of RSP Comment:

EPA has not justified the need, feasibility or cost-effectiveness of its proposed rule to set nationwide (1) new exhaust emission standards for heavy-duty engines and vehicles (trucks and buses); and, (2) new low-sulfur requirements for highway diesel fuel-the fuel used by most trucks and buses. EPA claims that the rule is needed to reduce levels of ozone and particulate matter (PM). However, most American citizens are expected to live in areas that meet current national ambient air quality standards (NAAQS) for both ozone and PM under current regulatory programs; and EPA does not show that the proposed rule would significantly reduce pollution levels in areas expected to fail one or both standards.

EPA's rationale for the "system" approach of tying together the engine emission controls and the diesel sulfur limits presumes that fuel sulfur will irreversibly damage the ability of engines to reduce emissions. Yet, EPA does not substantiate this assertion, and certainly has insufficient evidence to support the dramatic sulfur levels reductions it proposes (from a current cap of 500 ppm to a cap of 15 ppm). EPA's own analysis indicates that tightening the sulfur cap all the way to 15 ppm will have a relatively tiny impact on PM emissions and no impact on NOx emissions.

EPA has not conducted a benefit-cost analysis of the proposal, but its cost-effectiveness analysis is based on faulty analysis and biased assumptions. Making some straightforward adjustments, the cost-per-ton of PM removed by the proposed approach goes from EPA's estimate of $1,850 to over $80,000 (for going from 25 ppm to 15 ppm). This is far greater than the $10,000 per ton ceiling that President Clinton committed to for implementing NAAQS rules.