Regulatory Alert: EPA Releases Final Endangerment Finding for Piston-Engine Aircraft Lead Emissions

 

The U.S. Environmental Protection Agency (EPA) on October 18 released a final endangerment finding that lead emissions from piston-engine aircraft cause or contribute to air pollution that may reasonably be anticipated to endanger public health and welfare. The endangerment finding is the first step in a long process that requires EPA to develop lead emissions standards and the Federal Aviation Administration (FAA) to enforce such standards through the aircraft certification process.

In terms of what this means for airports, there are no immediate impacts. Despite EPA's actions, aircraft operators may continue to use leaded avgas, and airports and FBOs are not precluded from selling the fuel. However, AAAE, FAA, and our industry partners still recognize the need to transition to an unleaded avgas and are working together through the Eliminate Aviation Gasoline Lead Emissions (EAGLE) Initiative to ensure an accelerated and smooth transition as soon as possible.

AAAE will be hosting a virtual meeting with members on Thursday, October 26, at 2-3 p.m. ET, to discuss the endangerment finding and the transition to unleaded avgas. You can sign up to receive a calendar invite for the meeting using the form here. The purpose of the discussion will be to provide members with a brief overview of the endangerment finding, what it means for airports, the latest on the search for an alternative to 100LL, and related issues. This will be an opportunity for members to ask questions and hear from other stakeholders in the industry.

Background. Under the Clean Air Act, EPA has the authority to promulgate emission standards for specific air pollutants that are derived from aircraft engines, such as lead emissions from piston-engine aircraft that use leaded avgas. However, before developing these standards, the agency must determine that (a) the lead air pollution under consideration may reasonably be anticipated to endanger public health or welfare, and (b) emission of the lead air pollutant from piston-engine aircraft cause or contribute to this air pollution. Last year, EPA released and requested comment on a proposed endangerment finding, which outlined the agency's belief that lead emissions may reasonably be anticipated to endanger public health or welfare.

Final Endangerment Finding. EPA's final endangerment finding explains the basis for its determination that lead emissions may endanger public health or welfare and responds to over 53,000 comments that the agency received in response to last year's proposal. Based on our initial review, EPA reiterated many of the same arguments that were outlined in the proposed finding. EPA cited a wide range of scientific information regarding the effects that lead emissions can have on the health of humans, particularly children, and on agriculture products and aquatic ecosystems. The agency also noted that piston-engine aircraft are the largest single source of lead emissions to the air, contributing 70% of the lead entering the air annually.

EAGLE Initiative. AAAE is one of several organizations that founded a public-private partnership in 2022 called the EAGLE Initiative, which is aimed at accelerating the transition to unleaded avgas for piston-engine aircraft by 2030. The initiative includes FAA, the American Petroleum Institute, and the major GA trade associations. AAAE has helped educate FAA and the industry on airport-related needs and concerns regarding the transition to unleaded avgas. The EAGLE Initiative has developed a white paper that provides airports and other stakeholders with additional information about the implications of the endangerment finding, steps airports can take to minimize community exposure to lead emissions, and the status of potential alternatives to leaded avgas. You can find the document here.

Progress on Unleaded Avgas Alternatives. Last year, the industry witnessed a major development when FAA approved a supplemental type certificate (STC) to allow the General Aviation Modifications, Inc.'s (GAMI) 100-octane unleaded fuel (G100UL) to be used in all piston-engine GA airplanes with FAA type certificates. However, despite the agency's approval, the GAMI G100UL fuel is not commercially available and not being sold at any airports. Swift Fuels has one product, UL94, that is available at about 35 airports, but this fuel can only be used by about 73% of the certified piston-engine fleet. Swift Fuels has a second product, 100R, which is currently being evaluated and could receive FAA approval as early as 2024. Two other fuels are being tested in partnership with FAA through the Piston Aviation Fuels Initiative (PAFI). The goal of FAA and the general aviation industry is to have a fleet-wide alternative approved by 2030 or sooner.

What's Next? EPA's endangerment finding is the first step in a long process that requires FAA to enforce aircraft engine lead emission standards through the aircraft certification process. Below is an anticipated timeline for EPA and FAA to regulate aircraft lead emissions.

• October 2023: EPA issues a final endangerment finding after considering comments on a proposal that was released in fall 2022. 
• 2024-2025: EPA is expected to propose and finalize regulatory standards for lead emissions from aircraft engines. 
• 2025-2027: FAA is expected to promulgate certification standards that would require engine manufacturers to comply with the lead emission standards developed by EPA. 
• 2030: FAA and industry, through the EAGLE Initiative, have set 2030 as the goal for fully transitioning to unleaded avgas. 

Resources on EPA's Endangerment Finding
• EPA's Final Endangerment Finding for Piston-Engine Aircraft Lead Emissions 
• EPA's Press Release on the Final Endangerment Finding 
• EPA's Fact Sheet on the Final Endangerment Finding 
• EPA's Technical Support Document (TSD) for the Proposed Finding 
• EAGLE White Paper on Final Endangerment Finding 
• EAGLE Stakeholder Q&A on the Final Endangerment Finding