Air district studies leaded avgas at Sacramento Executive Airport; to add portable monitoring after further site review

The Sacramento Metropolitan Air Quality Management District received a staff briefing Sept. 25 on lead in aviation gasoline (avgas) with a focus on Sacramento Executive Airport and nearby communities.

Amy Roberts, division director for engineering and compliance at the district, said the agency prepared a white paper at the air pollution control officer’s request to summarize the national, state and local status of leaded aviation fuel and its potential impacts. “Our communities also care about exposure to different air pollutants such as lead and what can be done to reduce the impacts,” Roberts said.

Regulatory context: Roberts summarized recent federal and state actions. She said a 2023 EPA endangerment finding flagged small‑aircraft avgas as harmful to public health and that the FAA’s 2024 reauthorization act directs restrictions on leaded fuel use by 2030 while preserving existing availability until a safe transition can be certified. Roberts also cited California Senate Bill 1193, which sets a state target date to prohibit sale of leaded avgas by Jan. 1, 2031.

Local emissions and monitoring: Using flight activity and fuel‑use estimates, the district reported that lead emissions from Sacramento Executive Airport were estimated at about 0.5 ton per year, smaller than larger general‑aviation hubs such as Van Nuys. Roberts summarized ambient monitoring results including long‑term data from the Del Paso Manor monitoring station and targeted AB 617 community monitoring; those data sets showed concentrations well below the federal ambient lead standard (0.15 micrograms per cubic meter), with some samples in the observed datasets in the order of 0.004 µg/m3 or lower.

Portable monitoring and site concern: the district plans to locate its portable air monitoring laboratory for a one‑year assessment within the AB 617 community boundaries to capture traffic and airport emissions signals. Several board members expressed concern that the chosen site is adjacent to Mangum Park and the former gun range, historically subject to soil lead contamination. Director Serna and others asked whether monitoring at that location could conflate soil‑borne lead from the remediated gun range with airborne lead from avgas. Janice Lem Snyder of the district’s monitoring, planning and rules division answered that ambient monitoring measures constituents in the air and that additional analysis would be required to apportion sources; she said data analysis techniques could help delineate soil vs. aviation sources.

Board direction and staff commitment: Several directors asked staff for greater certainty before deployment. District Air Pollution Control Officer Dr. Ayala told the board he would pause placement until staff can provide additional analysis and assurances. “I want to give the board assurance that we're not going to place a lab because I share your concern,” Ayala said, and said staff will regroup and report back before any placement.

Fuel availability and transition challenges: Roberts noted technical and market hurdles with a near‑term switchover. She said manufacturers of high‑octane unleaded avgas are pursuing ASTM and related approvals (Swift Fuels has received ASTM designation supporting safety certification processes) but that commercial availability remains limited — Swift Fuels reported supply at a small number of airports. Roberts said the FAA grant assurances tied to federally assisted airports and safety certification processes for aircraft types make an immediate local ban of leaded fuel legally and operationally difficult. She also described examples from other California airports that either banned leaded avgas (drawing FAA complaint) or used incentives and subsidies to encourage early adoption of unleaded options.

What the board will do next: The presentation was a receiving file and no board action to adopt local limits or bans was taken. The board directed staff to continue engaging the community and airport operator, to explore monitoring approaches that can better separate soil versus airborne sources, and to coordinate on permitting and operational steps the airport would need should unleaded avgas be introduced.

Ending: Staff said the district will continue public engagement through the AB 617 steering committee, work with the Department of Airports on transition timing, and return with more analysis on monitoring site selection and data interpretation before the portable lab is deployed.