Disruptions to daily life and disturbances to the environment are among the consequences south metro-area mayors fear could land on their cities if a federal plan to reroute airplane traffic is implemented as it has appeared so far.

“People want go to our parks and have a picnic lunch, or read a book under a tree,” said Littleton Mayor Debbie Brinkman, who said residents could have to react to quality-of-life changes. “The community isn’t equipped to deal with that.”

The Federal Aviation Administration’s NextGen project — an effort to increase safety and efficiency of air transportation across the country — began in 2007 and is expected to be largely in place by 2025. The FAA tags it as “one of the most ambitious infrastructure projects in U.S. history.”

In the Denver area, the potential overhaul lies in the NextGen Denver Metroplex project, which aims to optimize arrival and departure at local airports, including Denver International Airport, Centennial Airport and some others. The rub in the south suburbs is a possible moving of flight paths that generally stay east of Interstate 25 and south of DIA to a new corridor that could run above the areas of Littleton, Englewood and Cherry Hills Village, for example.

The FAA says aircraft altitudes will be similar to what’s being flown today, but Centennial Airport officials said the proposal would change one route’s approach into the airport “dramatically.”

“The BRNKO route generates multiple concerns,” said Robert Olislagers, executive director of Centennial Airport, using the path’s technical name. “First, if implemented, it puts aircraft over communities that have previously not seen much or any air traffic.”

The Metroplex plan isn’t finalized, and it’s unclear exactly what areas would be affected and what degree of added air traffic they could end up with. A smaller general aviation facility like Centennial Airport brings less noise than DIA, but Centennial Airport still averages about 900 takeoffs and landings daily. Most of those wouldn't use the proposed routes if the plan is approved, according to the FAA.

It’s also unclear what the effect on air traffic would be for areas south of the airport, in northern Douglas County, where residents currently report noise complaints in some of the most concentrated amounts.

But local mayors have sounded a clarion call, enlisting Colorado’s congressional delegation in the effort to push back against possible quality-of-life problems.

“Please know that I will fight for both you and me — and our constituents — to be able to participate in the FAA’s processes and be heard,” U.S. Rep. Jason Crow, of Littleton’s congressional district, said in a Jan. 9 letter to Brinkman.

‘It’s a David and Goliath’

Despite the lack of clear details on what changes could happen, the mayors of Sheridan, Englewood, Littleton, Greenwood Village, Cherry Hills Village and Centennial have been consistently discussing the issue.

“We don’t know all the flight patterns yet,” said Linda Olson, Englewood’s mayor, who said the mayors meet informally each month for lunch. “But the last four times we’ve met, this has been the topic. And those are the cities that are going to be largely impacted by this.”

Olson and Brinkman hope to round up community and business leaders, as well as Colorado’s senators, Crow and U.S. Rep. Diana DeGette, the Democrat who represents Denver, Englewood, Cherry Hills Village and Sheridan. Crow represents Littleton, Centennial and Greenwood Village in the area, along with Aurora and Highlands Ranch.

We want to “do whatever we can to keep this in the public eye,” Brinkman said.

U.S. Sen. Cory Gardner, R-Yuma, wrote a letter to the FAA in February 2018 asking it to hold another public meeting with local communities after it canceled its participation in a “widely advertised public meeting” the night before it was held.

Allen Kenitzer, an FAA spokesman, said the FAA suggested to Centennial Airport that a requested November 2017 meeting should be forwarded to an FAA regional official a few weeks beforehand. The FAA responded two days before the meeting that the regional official wouldn’t be able to attend but was open to other dates, Kenitzer said.

“The FAA has made it virtually impossible for concerned local governments and citizens to obtain meaningful information concerning the location of flight paths and their associated impacts,” wrote Laura Christman, former Cherry Hills mayor, in a November 2017 letter to the Centennial Airport Community Noise Roundtable. That group is a collection of area officials and citizens who discuss aircraft noise issues.

The FAA sent out a notification about the project in May 2016, and it hosted 12 public workshops in the Denver metro area to explain the project and take comments between April and May 2017. But Brinkman said the information about the project has been sparse.

More public meetings are slated for this spring, but when and where are as yet unclear.

Brinkman is prepared to fight potential changes for suburban Denver — a daunting task, she said, given the agency has enacted changes in places like Los Angeles.

“It’s a ‘David-and-Goliath’” conflict, Brinkman said.

‘What is the cost?’

Another sticking point for south metro officials is the lack of a rigorous review of what environmental consequences the Metroplex project will bring. The FAA may consider impacts to noise, air quality, wildlife, and historic and cultural resources, among other factors, according to its notice.

But that Environmental Assessment will be weaker than the FAA’s Environmental Impact Study process, and the agency considered environmental benefits the project is expected to bring, according to Crow’s letter.

“The FAA estimates the project will save 0.6 million gallons — $1.8 million — of fuel and cause an estimated 5.4 thousand metric ton drop in carbon emissions,” Crow’s letter states.

But Brinkman questioned the effect on the metro area’s quality of life, citing, for example, Littleton’s South Platte Park.

“What is the cost … when you’ve got a 900-acre park that has over 250 types of birds that come in and out? (What about) people who have large parcels with animals?” Brinkman said.

In her letter to the noise roundtable, Christman expressed concern that a new flight path could negatively impact school children, cause sleep disturbance and decrease the value of homes.

A study in the International Journal of Environmental Research and Public Health, released last year, examined the impact of a NextGen flight-pattern change for New York’s LaGuardia Airport and determined that such systems could cause “serious health conditions for the overflown communities.”

It also pointed to previous research that links high levels of aircraft noise to development of cardiovascular disease and anxiety. But the New York study noted it only considered one route in one city and shouldn’t be taken as a blanket assessment of flight-path changes.

The FAA has said small numbers of aircraft would use the proposed BRNKO path, but that isn’t the only Centennial Airport route that may see changes, and another new route, the PINNR path, also appears to put its traffic over, broadly, the Englewood-Littleton area, according to FAA maps.

Brinkman also guessed that businesses also could see drawbacks from frequent plane descents. Some in the business community have expressed concern to the South Metro Denver Chamber of Commerce, said Robert Golden, chamber president.

The chamber “shares the same concerns that our local municipalities and Centennial Airport have raised,” Golden said. We “encourage the FAA to listen to our cities, local airports and most importantly, the citizens.”

Andrea Suhaka, an alternate representative on the noise roundtable, said she’s concerned the plan will bring aircraft noise over thousands more people who live along the East Arapahoe Road corridor.

“Absolutely no one thinks Metroplex is a good idea,” Suhaka said.

‘Not just checking boxes’

Centennial Airport sits east of I-25, just south of Centennial, on land in unincorporated Arapahoe and Douglas counties. The airport has retained legal counsel with “significant expertise in aircraft noise issues,” Olislagers said.

“However, we want to avoid litigation,” Olislagers said. “We just want the FAA to do what is legally required of them and point that out if necessary.”

A letter the airport sent the FAA in June 2017 argued that the agency isn’t following its own rules, by evaluating the potential effects of the Metroplex plan separately from the area navigation, or RNAV, change to local airspace in 2013.

That change affected Centennial Airport’s flight paths, but only slightly and “not to any material degree,” Olislagers said. Denver International Airport did not respond for comment on how RNAV changed its flight paths, and the airport has not taken a position on the Metroplex plan, said Emily Williams, DIA spokeswoman.

Centennial Airport’s letter also said the FAA’s carrying out separately of the analysis of high-altitude changes and lower-altitude routes violates the agency’s rules, adding that high-altitude changes will result in altered lower-altitude routes, too.

“Those changes will have the potential for far greater impacts to communities,” the letter read. “As the FAA should have learned from experience with Metroplex implementation (elsewhere), these changes can result in considerable community disruption and controversy.”

The letter urges the agency to conduct its environmental analysis with more rigor than the minimum standards mandate, if “the FAA is to avoid the firestorm that has been created” in places where it implemented NextGen with minimal analysis, like Baltimore, Washington, D.C., and Phoenix.

In Phoenix, the FAA put new routes into effect in September 2014 and did not share its environmental conclusions with airport management until the day before the routes were to go into effect, according to a 2017 U.S. Court of Appeals case. Before implementation, the agency had only spoken with low-level employees in the city’s Aviation Department.

In the next two weeks, the airport received more noise complaints than it had in all the previous year. Residents said flights were too frequent and rattled windows and doors in their homes. Some said they had trouble sleeping, having conversations outside or feeling comfortable indoors without earmuffs. In response, the FAA held a public meeting that drew 400 attendees and hundreds of comments. The court ruled the FAA failed to properly notify the city and ordered it to work with Phoenix on a more collaborative process.

The lion’s share of increased air traffic over Phoenix’s historic areas and parks was by jets, whereas larger planes have less presence at Centennial Airport. But Centennial Airport still received noise complaints from 362 households from January through November 2018, according to airport data.

The FAA has been in contact with local officials in metro Denver — unlike in Phoenix — but Olislagers said communities must also be given adequate opportunity to be heard and to have legitimate concerns be addressed and, if necessary, mitigated.

It’s important for the public to know the project is the FAA’s, not Centennial Airport’s, Olislagers said.

Olislagers hopes the Metroplex process can be a model for true engagement and “not merely checking boxes,” the airport’s letter read.

DIA, airlines ‘big dogs’

The proposed BRNKO route appears to be intended to move Centennial Airport’s traffic out of the way of DIA’s, Olislagers said.

DIA and “the airlines are the big dogs, and Centennial Airport plays second fiddle,” Olislagers said. “We get that.”

But under the new path, aircraft flying to Centennial Airport would fly longer distances, burning more fuel and adding to carbon emissions while the airlines receive the benefit of reduced fuel burn and emissions, Olislagers said.

The suggested corridor along the foothills, toward the south metro area, is heavily traveled by all types of aircraft, and pilots have expressed concerns over jets and small airplanes crossing in a very tight area, he added.

Candace Moon, a Centennial city councilmember and representative on the airport’s noise roundtable, said it’s a waiting game to see how the proposal might affect communities. More information may come out in the FAA’s public workshops this spring, where public comment will be taken.

“Until they make a final decision,” Moon said, “it’s really hard to say.”