Revision of Standards of Performance for Nitrogen Oxide Emissions From New Fossil-Fuel Fired Steam Generating Units; Revisions to Reporting Requirements for Standards of Performance for New Fossil-Fuel Fired Steam Generating Units

Pursuant to section 407(c) of the Clean Air Act, the EPA has reviewed the emission standards for nitrogen oxides (NO<INF>X</INF>) contained in the standards of performance for new electric utility steam generating units and industrial-commercial-institutional steam generating units. The EPA proposed revisions to 40 CFR part 60, subparts Da and Db based on this review on July 9, 1997. The EPA received 70 public comments on the proposed rule changes. These comments were reviewed, and this document reflects the EPA's responses to the issues raised by the commenters. This action promulgates the revised standards of performance. The final revisions change the existing standards for NO<INF>X</INF> emissions by reducing the numerical NO<INF>X</INF> emission limits for both utility and industrial steam generating units to reflect the performance of best demonstrated technology. The final revisions also change the format of the revised NO<INF>X</INF> emission limit for new electric utility steam generating units to an output- based format to promote energy efficiency and pollution prevention. However, in a change from the proposed language, the EPA is revising the standard for existing utility boilers that become subject to subpart Da through modification or reconstruction to be in an equivalent input-based format. As a separate activity, the EPA also reviewed the quarterly sulfur dioxide (SO<INF>2</INF>), NO<INF>X</INF>, and opacity emission reporting requirements of the utility and industrial steam generating unit regulations contained in subparts Da and Db. The final rules will allow owners or operators of affected facilities to meet the quarterly reporting requirements of both regulations by means of electronic reporting, in lieu of submitting written compliance reports.