The Environmental Protection Agency in late January issued a final rule in which it determined that the risks from combustion turbines due to emissions of hazardous air pollutants (HAPs) are acceptable and that the existing NESHAP provides an ample margin of safety to protect public health.
Significantly, the final rule does not impose any emission standards on the vast majority of combustion turbines.
On January 31, EPA Administrator Andrew Wheeler signed the final rule for the NESHAP: Stationary Combustion Turbines Residual Risk and Technology Review.
EPA finalized its proposed determinations under Clean Air Act (CAA) Sections 112(f) and 112(d)(6) residual risk and technology (RTR) review provisions.
Along with determining that the risks from combustion turbines due to emissions of HAPs are acceptable and that the existing NESHAP provides an ample margin of safety to protect public health, the agency also finalized its proposed determination that there are no new cost-effective controls under the technology review that would achieve further emissions reductions from the source category.
Accordingly, the final rule does not modify the current NESHAP standards for combustion turbines based on the RTR.
The rule also finalized several proposed amendments to the stationary combustion turbine NESHAP to remove the exemption for periods of startup, shutdown, and malfunction (SSM) and to impose electronic reporting requirements.
The compliance date for both revised provisions is 180 days after the effective date of the rule, which will be the date of publication in the Federal Register (as of Feb. 21, the final rule has not been published in the Federal Register).
Other than removing the SSM exemption, EPA did not undertake any so-called “gap filling” to address HAP emissions or emission points not covered in the current NESHAP.
Final rule does not impose emission standards on most combustion turbines
The final rule does not impose any emission standards on the vast majority of combustion turbines (i.e., gas-fired combustion turbines) because:
- EPA undertook no “gap-filling,” aside from eliminating the SSM exemption and most notably declined to establish standards for existing (i.e., pre-2003) combustion turbines, which currently are not subject to a NESHAP under the 2004 rule; and
- EPA did not finalize its proposed removal of the administrative stay of the Maximum Achievable Control Technology standards for new (i.e., post-2003) lean premix and diffusion flame-gas-fired turbines
The agency noted in the preamble to the final rule that because it needed more time to review comments on the removal of a stay and the petition to delist the stationary combustion turbine source category under CAA Section 112(c)(9)(B) filed by an industry coalition during the rulemaking in August 2019, it determined not to finalize the removal of the stay in the RTR final rule.
“While the Association supports the final rule, it is disappointed that the agency declined to revise the proposed startup times to account for units that may require additional time due to site-specific factors as we requested in comments on the proposed rule,” said Carolyn Slaughter, Director, Environmental Policy, at the Association.
Once the final rule is published in the Federal Register, parties will have sixty days to challenge the rule in the D.C. Circuit and/or file petitions for reconsideration with the EPA.
The pre-publication version of the final rule is available here.