EPA seeking new comment on coal- and oil-fired boiler rule

The U.S. Environmental Protection Agency is reopening the comment period, strictly for new comments on unit startup and shutdown conditions, in a rule affecting coal- and oil-fired boilers.

On Nov. 30, 2012, the EPA published in the Federal Register the proposed rule, “Reconsideration of Certain New Source and Startup/Shutdown Issues: National Emission Standards for Hazardous Air Pollutants from Coal- and Oil-fired Electric Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility, Industrial-Commercial-Institutional, and Small Industrial-Commercial-Institutional Steam Generating Units.”

That proposal opened for reconsideration certain issues, including those related to startup and shutdown. On April 24, EPA finalized reconsideration of all the issues included in the proposed rule except those related to startup and shutdown, the agency said in the notice to be published in the June 25 Federal Register. The EPA said it is now reopening the public comment period to solicit additional input on specific issues raised during the initial public comment period related to the proposed revisions to the requirements and definitions related to periods of startup and shutdown. The EPA also requests comment on the additional technical analyses it conducted in response to public comments on this subject.

The National Emission Standards for Hazardous Air Pollutants (NESHAP) rule is referred to as the Mercury and Air Toxics Standards (MATS), and the New Source Performance Standards rule is referred to as the Utility NSPS.

On Feb. 16, 2012, the EPA issued the final MATS and Utility NSPS. In the final MATS rule, the EPA included a work practice standard applicable during periods of startup and shutdown rather than finalizing the proposed requirement that sources comply with numerical limits during such periods. In the Utility NSPS, the EPA included the same work practice for particulate matter (PM) emissions during periods of startup and shutdown. The work practice standard was designed to minimize emissions of hazardous air pollutants (HAP) and PM during periods of startup and shutdown by requiring sources to maximize the use of clean fuels during such periods when electric utility steam generating unit (EGU) temperatures and air flow may not be enough to effectively engage certain air pollution control devices (APCD).

Because the agency did not propose a work practice standard for periods of startup and shutdown, the EPA decided it was appropriate to reconsider the startup and shutdown provisions to allow the public an opportunity to comment on the requirements. That led to the Nov. 30, 2012, Federal Register notice.

The Nov. 30 action announced, among other things, reconsideration of certain new source standards for MATS and the requirements applicable during periods of startup and shutdown for MATS and the startup and shutdown provisions related to the PM standard in the Utility NSPS and proposed revisions to these identified provisions. The EPA also proposed certain technical corrections.

During the comment period, the EPA received data and other information from industry about EGU startup, and the industry commenters recommended that the startup and shutdown provisions as proposed be further amended. The comments raised several significant issues regarding the definition of startup, the types of “clean fuels” that must be used during startup, the means by which non-mercury (Hg) emissions are calculated during periods of startup and shutdown (e.g., requests for the use of a default diluent cap and for the use of a default electrical production rate), and the manner in which EGUs that share a common stack demonstrate compliance during periods of startup and shutdown.

Given the significance of these comments, the EPA believes it is appropriate to request new comment on these issues. It is only reopening for comment the startup and shutdown provisions in the MATS rule and the startup and shutdown provisions related to PM in the Utility NSPS.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.