National Emission Standards for Hazardous Air Pollutants: Generic Maximum Achievable Control Technology Standards Residual Risk and Technology Review for Ethylene Production

This action finalizes the residual risk and technology review (RTR) conducted for the Ethylene Production source category regulated under National Emission Standards for Hazardous Air Pollutants (NESHAP). In addition, the U.S. Environmental Protection Agency (EPA) is taking final action to correct and clarify regulatory provisions related to emissions during periods of startup, shutdown, and malfunction (SSM), including removing general exemptions for periods of SSM, adding work practice standards for periods of SSM where appropriate, and clarifying regulatory provisions for certain vent control bypasses. The EPA is also taking final action to revise requirements for heat exchange systems; add monitoring and operational requirements for flares; add provisions for electronic reporting of performance test results and other reports; and include other technical corrections to improve consistency and clarity. We estimate that these final amendments will reduce hazardous air pollutants (HAP) emissions from this source category by 29 tons per year (tpy) and reduce excess emissions of HAP from flares by an additional 1,430 tpy.