EPA Proposes Standards To Reduce Pollutants from Stationary Diesel Engines

EPA is proposing standards to reduce emissions of air pollutants from stationary compression ignition internal combustion engines -- standards that will subject these engines to the same stringent levels required by EPA's nonroad diesel engine rule.

As proposed, the rule will affect 81,500 new stationary diesel engines and result in total pollutant reductions of more than 68,000 tons in 2015. The proposed standards, known as New Source Performance Standards, will reduce harmful emissions of nitrogen oxides (NOx), particulate matter (PM), sulfur dioxide (SO2), carbon monoxide (CO), and hydrocarbons (HC) from new, modified, and reconstructed stationary diesel internal combustion engines.

Emissions reductions will occur gradually from 2005 to 2015, reaching reductions of 90 percent or more from baseline levels in some cases. EPA estimates the total nationwide annual costs for the rule to be $57 million in the year 2015.

Stationary diesel internal combustion engines are used to generate electricity and operate compressors at facilities such as power and manufacturing plants. They are also used in emergencies to produce electricity and pump water for flood and fire control. EPA will accept comments on this proposed rule for 60 days following publication of the proposed rule in the Federal Register.

The rule would take effect in three, increasingly stringent stages:

1. The first is a transition period to control emissions from diesel engines built after this rule is proposed but before the 2007 model year. Owners or operators would comply with this regulation by purchasing an appropriate engine and by operating and maintaining the engine according to the manufacturers' instructions.

  • In most cases, the owner/operator would purchase a certified nonroad engine for stationary use and that would be sufficient to comply with the regulatory requirement.
  • In less likely cases, the owner/operator would purchase a non-certified engine and would have several options (using manufacturers emissions data or previous test results on a similar engine, or stack test data) to demonstrate compliance with the pre 2007 emission limits.
  • In all cases, the information which demonstrates new engine compliance and the appropriate maintenance records must be kept on site.

2. Beginning in model year 2007:

  • Engine manufacturers would be required to certify that all new, modified or reconstructed stationary diesel engines meet the stringent emissions levels for NOx, PM, CO, and HC that are required for the same size engine and model year for nonroad diesel engines in the categories known as Tiers 1 through 4, with a few exceptions.
  • Stationary emergency diesel engines would be required to be certified to meet emissions limits through Tier 3 and also Tier 4, however, Tier 4 requirements for them do not require add-on controls.

3. Beginning with 2011 model year engines, add-on controls would be required to achieve the emission limits for non-emergency engines.

EPA issued the proposal in response to a Dec. 8, 2003, lawsuit filed by Environmental Defense. The lawsuit was settled by a consent decree that the court approved on Sept. 27, 2004, requiring EPA to issue proposed national emission standards on June 29, 2005, and to finalize the standards on June 28, 2006.

"EPA's new clean air standards will protect public health and the environment by applying modern pollution control standards to new diesel electrical generators, compressors and pumps," said Environmental Defense Director of Special Projects Mark MacLeod.

According to Environmental Defense, EPA's stationary engine regulations rely on control technology that is already being required and has proven cost effective for similar engines in mobile equipment. EPA's action also builds on the efforts of several states, including Texas and California, which previously adopted emissions standards for stationary engines.

Allen Schaeffer, executive director of the Diesel Technology Forum, stated that the industry is firmly committed to continuous progress and a cleaner environment. "We see this proposed regulation as an opportunity to continue the application of the clean diesel system to yet another category of diesel engines and equipment, and look forward to working with EPA to bring these new standards to life beginning in 2007," he stated.

"EPA rules issued last year for off-road machines and equipment like those used in construction, farming and mining will cut key emissions in that sector by more than 90 percent starting in 2008. It only makes sense that we continue diesel's environmental and technological progress with these stationary engines as well," Schaeffer said.

For more information on this action visit: http://www.epa.gov/ttn/oarpg/t3/fact_sheets/stadieselengineprop_fs.html.

This article originally appeared in the 07/01/2005 issue of Environmental Protection.

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