On March 9, 2020, EPA published its final “risk and technology review” for the standards it adopted in 2004 to regulate emissions of hazardous air pollutant (HAP) from natural gas-fired combustion turbines. Like most other such reviews, EPA confirmed that the risks presented by HAP emissions from the source category are acceptable with an ample margin of safety. EPA also concluded that there are no new cost-effective controls for reducing those emissions.

EPA has been working frantically to complete dozens of risk reviews to meet several court orders issued after EPA missed the eight-year statutory deadlines for those reviews. But one thing makes the EPA’s review of the gas turbine standards different: the gas turbine standards have never taken effect because they were stayed shortly after issuance. As a result, EPA’s review not only confirms the standards do not need to be made any more stringent, it also confirms they were never really needed in the first place. Although EPA found that ethylene oxide emissions from chemical manufacturing activities collocated with some turbines may present a somewhat higher level of risk, EPA concluded the risk associated with turbine emissions is low, even though the standard for those emissions has never been implemented.

In the proposed review published just under a year ago, EPA sought comment on whether its stay of the standard should be lifted. Several commenters strongly opposed that idea because it could potentially require all turbines built after the original applicability date of 2003 to comply with the standards in 180 days. Since many facilities have never conducted testing to determine if controls would be needed to comply, much less evaluated how long it would take to design and install those controls, compliance within 180 days was likely to be infeasible. In its final notice, EPA left the stay in place, at least for now, as it continues to review the public comments received on the issue.

While EPA has not made a final decision on whether to lift the stay, EPA has indicated that it plans to evaluate whether to “de-list” gas turbines from the HAP program entirely, as requested by several industry representatives in a petition submitted last year. According to that petition, the data underlying EPA’s modeling analysis contained errors that, once corrected, produce modeling results confirming that no facility in the source category presents a level of risk that warrants regulation. However, with only eight months left before the next presidential election, the final decision on whether to grant or deny that petition will almost certainly be made by the next administration.

For more information on the HAP standards for combustion turbines, please contact Mack McGuffey or Melissa Horne.