NACAA Comments on Proposed Stationary Combustion Turbine RTR

May 21, 2019 – NACAA has submitted comments on the proposed “National Emission Standards for Hazardous Air Pollutants: Stationary Combustion Turbines Residual Risk and Technology Review” that was published in the Federal Register on April 12, 2019.  EPA proposed to determine that the risks from the source category are acceptable and that there are no new cost-effective controls.  The proposal would revise the requirements for periods of startup, shutdown and malfunction to be consistent with recent court decisions; require electronic reporting of performance test results and compliance reports; and remove the stay of the standards for new gas-fired stationary combustion turbines. NACAA’s comments expressed concern about the maximum individual risk identified in the proposal, largely due to emissions of ethylene oxide (EtO), and urged EPA to use the updated Integrated Risk Information System (IRIS) risk value for EtO in setting regulations that will address risks from this and other source categories.  NACAA also commented on certain elements of EPA’s risk assessment methodology, including the use of census tract centroids in determining long-term exposures, consideration of facility-wide risks and strategies for evaluating acute exposures.