Rocky Mountain Metropolitan Airport said Wednesday it will fully shift from the use of toxic leaded aviation gasoline to unleaded fuel at its facility within four years.
If the Jefferson County airport meets its target, it will beat by three years a federal mandate that piston engine aircraft switch to unleaded-only fuel by 2030.
The announcement comes as neighbors living around the general aviation airport have in recent years decried contamination from lead particles that descend from overhead propeller plane emissions — many of which are flight-school aircraft. They have also complained of continuing noise overhead from all the flights at the airport, though that’s a problem that changing to unleaded fuel won’t mitigate.
Rocky Mountain saw nearly 300,000 takeoffs and landings last year, and even more are expected by the end of 2023.
“The majority of flight schools can switch to the 94UL,” airport director Paul Anslow said Wednesday, as airplanes buzzed the skies above the tarmac at the county-owned airport near Wadsworth Parkway and U.S. 36.
The 94UL fuel is essentially a transition unleaded gasoline. It works with most, but not all, of the 350 prop aircraft that are based at Rocky Mountain Metropolitan Airport, Anslow said.
The Federal Aviation Administration approved the use of unleaded 100UL fuel for all aviation piston engines a year ago, but the infrastructure to deliver that higher-octane — and more resilient — fuel is still being rolled out nationwide. It is still appreciably more expensive than leaded fuel, though the price differential is coming down, Anslow said.
“Just the success story of the airport switching to 94UL fuel is a huge win,” said Superior Trustee Jason Serbu, who serves as the town’s liaison to the airport’s Community Noise Roundtable. He’s received a barrage of complaints from residents about lead exposure in the Rock Creek neighborhood just north of the airport.
Lead is particularly hazardous to children and there is no accepted safe level of exposure, according to the Environmental Protection Agency. The EPA says lead can cause slow development, behavior and learning problems, low IQ, and hyperactivity and hearing problems in children.
One of the most comprehensive lead studies involving airports was conducted near Reid-Hillview Airport in east San Jose, California. The study, released in 2021, found that children living within a half-mile — and downwind — of the facility had lead concentrations in line with those found in children living in Flint, Michigan, during the water contamination crisis there several years ago.
Blood lead levels were 20% higher in those children than in children living between a half-mile and 1.5 miles from the airport.
Lafayette resident Bri Lehman said Wednesday’s announcement is “an excellent start” to addressing longstanding concerns in communities surrounding the airport.
But aircraft noise remains a big problem, she said.
“They like to fly directly over my roof” at 3 a.m., said Lehman, who is part of a loosely organized group called Save Our Skies Alliance. “It’s like you’re trying to think and someone in the next room turns on a blender.”
The ongoing noise issues prompted Colorado Reps. Joe Neguse and Brittany Pettersen, both Democrats, to send a letter to the FAA last month demanding that the agency more forcefully address the problem.
Charlene Willey, whose Westminster home sits right under a Rocky Mountain airport flight path, said the noise has only gotten worse in the last few months.
“There’s been no mitigation that we’re aware of for that,” she said.
But Serbu, the Superior trustee, said pilots at Rocky Mountain airport increasingly are using a new voluntary flight path that takes night flights over a less populated area along U.S. 36.
“We’re not going to let this issue fall by the wayside,” he said.
Centennial Airport, Colorado’s largest general aviation airport, became the first in the state to offer unleaded fuel in the spring. It already accounts for nearly 20% of the fuel used by prop planes at the airport, according to airport data provided to The Denver Post.
Anslow, the director at Rocky Mountain Metropolitan Airport, said its transition to unleaded fuel will take time, starting with the recent purchase at a Denver International Airport auction of a $50,000, 1,200-gallon unleaded fuel truck. Next year, the airport is planning to procure a 12,000-gallon tank to store 94UL fuel on site.
In 2026, the airport plans the broad deployment of 100UL fuel throughout its operations.
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