The federal government's final analysis of a plan to reroute airplane traffic in the Denver metro area didn't offer changes to proposed flight paths for Centennial Airport that have riled up local …
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From Nov. 18 through Dec. 20, the public can comment on any of the changes made from the draft environmental assessment to the final environmental assessment.
Click the button on the right side of the screen that says “Submit Your Comments” here.
Changes between the draft study and final study are listed here.
The rest of the documents related to the plan are available here. The link labeled "final EA full document" still goes to the draft, but the one above it lists changes made in the final study.
Older methods to direct air traffic in the metro area largely depend on navigational aids on the ground or radar by air traffic controllers, according to the Federal Aviation Administration.
Area navigation, or RNAV, can put pilots on more direct routes, generally through satellite technology. It requires less communication between air traffic control and pilots and makes for more efficient use of airspace, according to the agency. RNAV changes have been part of NextGen, a set of updates the FAA is making in the Denver area and around the nation.
The Metroplex plan is another part of the NextGen updates. It aims to make further changes with new flight paths for airports in metro areas like Denver.
The potential airports affected are Centennial Airport, Rocky Mountain Metropolitan Airport in the Broomfield area, Denver International Airport, Northern Colorado Regional Airport in Loveland and Greeley-Weld County Airport.
The FAA held 12 public meetings, mostly in the Denver metro area, at which FAA representatives answered questions about the project and took written comments. Those ran from April 29 to May 16.
After that, the agency took comments online and by physical mail during a roughly six-week public comment period, which lasted until June 6, about the April 22 draft EA.
The FAA sent out an announcement of the project in May 2016. Public comment was initially accepted through early June 2016, according to the notice.
The agency hosted 12 public workshops to explain the project and take comments between April and May 2017. It also fielded online comments for a month afterward.
It’s anticipated the FAA will begin implementation of the project in spring 2020.
Developments surrounding the FAA's Metroplex plan over the past few months:
• Mayors in Englewood, Littleton and beyond in the Denver metro area raised concerns about new flight paths: South metro Denver area braces for potential flight-path changes
• The FAA's draft of the study on Metroplex says the plan will have "no significant impact" on the metro-area noise, air quality, wildlife, and historic and cultural resources: Metroplex flight-path impact portrayed as minor by feds
• At one of the FAA's public meetings, the agency says the notable changes in flight paths will only involve about eight flights per day: Noise impact of altered flight paths to be mostly small, FAA says
• Centennial Airport writes a letter to the FAA, saying its plan would put planes in "volatile conditions" and that the agency did not properly study its environmental effects: Centennial Airport says FAA left gaps in flight path study
• Centennial Airport files legal action against the FAA in federal court, pushing for a further look at what the plan's effects could be: Centennial Airport taking FAA to court over flight paths
• Centennial Airport pulls its legal action on a technicality but plans to bring it again: Centennial Airport legal action against FAA over flight plans delayed
The federal government’s final analysis of a plan to reroute airplane traffic in the Denver metro area didn’t offer changes to proposed flight paths for Centennial Airport that have riled up local officials.
Wheels have been turning for years on the Federal Aviation Administration’s plan to optimize arrival and departure at local airports — it’s called the Denver Metroplex project, and it includes Denver International Airport, Centennial Airport and some others. An FAA study, called a draft environmental assessment, looked at impacts the project could have on noise, air quality, wildlife, and historic and cultural resources.
The proposed change in flight paths is expected to have “no significant impacts” on those aspects of the project’s area, including metro Denver and the Greeley area, according to the April 22 draft EA.
Now, the final version of that study is out. And although it shows that the FAA made changes to a proposed flight path over the Boulder area based on public complaints, the notable planned new paths in south metro Denver remain unchanged.
“We have the very same concerns as before,” said Robert Olislagers, executive director of Centennial Airport. “The FAA has ignored perfectly good reasons to go take this process slowly and carefully.”
The final study, released Nov. 18, does not change the determination that the plan will not have significant impacts. That likely means a further review, called an environmental impact statement, isn’t necessary before the plan is put into action.
But “no final decision has been made,” said Allen Kenitzer, an FAA spokesman. Comments can be made through Dec. 20 on the FAA’s website.
No significant impacts have been found to be expected by any draft EA or final EA of the 11 active or completed Metroplex projects around the nation, and all projects have been reviewed with EAs to this point, Kenitzer said.
Centennial Airport is still urging the FAA to remove two proposed flight paths from Metroplex.
Planes today already travel the area that one proposed path, PINNR, would cover in the Denver area, according to the FAA. That’s a proposed route that travels south, roughly above Interstate 25, starting around Greeley and turning southeast over the Denver area.
The proposed BRNKO route would take arrivals from the northeast that currently stay east of I-25 and move them farther north, joining up with PINNR near Greeley and traveling in that same corridor as flights move south.
BRNKO only entails about six flights per day on average that would be moved from an older corridor, according to the FAA. Centennial Airport sees about 1,055 daily takeoffs and landings combined, but most of those would not use the proposed Metroplex routes, according to the FAA.
But Centennial Airport argues the BRNKO route will put pilots over unsafe territory: the foothills, where volatile wind conditions can be unpredictable, the airport has said.
The FAA has made a handful of tweaks to the list of proposed new flight paths, and one path, the ZIMMR, represents a change for the Boulder area.
The existing FOOOT path — which the ZIMMR would replace — flies directly over the south-central portion of the City of Boulder, and an update to the proposed ZIMMR moved the path even farther to the south than the original proposed change, according to the final EA study.
“Recognizing the important role community engagement plays for the successful implementation of the DEN Metroplex, public comments were reviewed and considered for potential changes to procedures,” the final EA read.
From April 22 through June 6, the FAA accepted comments on the draft EA through the FAA website, at public meetings, and through physical mail and email. The more than 500 comments received — from private citizens and groups, elected officials and government bodies — are all included in the final EA with general responses to each comment based on the topic it deals with, such as noise or frequency of flights.
“Looking at the impacts on Centennial Airport and our surrounding impacted communities, nothing appears to have changed,” Olislagers said of the final study compared to the draft.
Olislagers has argued that the FAA didn’t consider the impact of the part of flight that occurs below 3,000 feet above ground, and that leaves unclear how much communities could be affected. Littleton, Centennial, Cherry Hills Village, Lone Tree, Castle Rock and other nearby cities could experience notable effects, Olislagers said.
The airport, in a June 5 letter to the FAA, contended that the final part of flight wasn’t adequately analyzed by the agency, “leaving the most important concerns, noise and overflight at the lowest altitudes over those communities unanswered,” the letter read.
In the final EA, the FAA clarified that all noise modeling was done from the surface to 18,000 feet above ground, Kenitzer said, and all noise results were reported at ground level. Kenitzer did not directly address an emailed question of whether noise was analyzed for the portion of flight that occurs below 3,000 feet above ground, specifically, or just the part of proposed paths at which planes would be above 3,000 feet.
It appears that, after changes to the Metroplex plan shown in the final EA, fewer people would experience notable noise increases. The draft EA reported that about 100 people in rural parts of Jefferson, Adams and Elbert counties would likely experience an increase of 5 decibels in areas where the average noise would usually vary between 45 and 60 decibels. Conversation in restaurants generally hovers around 60 decibels, according to a Purdue University chart. Upper-70s levels are annoyingly loud to some people, the chart said.
Now, about 70 people would experience a 5 dB increase in areas where average noise usually varies between 45 dB and 60 dB. One is located in unincorporated Jefferson County, and the other sits in unincorporated Elbert County.
But that’s the extent of the notable noise changes, according to the FAA — and only increases of 1.5 dB or more in areas exposed to 65 dB and up are considered to “exceed threshold of significance,” according to the draft report.
In the June 5 letter, Centennial Airport also pushed for the FAA to complete more studies mandated by the FAA Reauthorization Act of 2018, a law passed by Congress, before it puts the Metroplex plan in motion. Those studies focus on the FAA’s “community involvement” practices and the effect of noise on health, among other items, according to the airport’s letter.
The FAA said it will comply but that it isn’t required to do so before Metroplex is implemented.
“Congress did not place a moratorium on project implementation, including the proposed Metroplex projects,” Kenitzer said.
Earlier this year, Centennial Airport took legal action — a petition for review — against the Federal Aviation Administration over the Metroplex project.
That move came in the U.S. Court of Appeals for the District of Columbia Circuit. In the June 19 legal filing, the Arapahoe County Public Airport Authority — the government body that oversees the airport — asked the court to review the FAA’s study, its determination that an environmental impact statement isn’t needed and its proposed changes in flight procedures.
The airport later withdrew its case because the filing was premature, and the court formally dismissed the case Aug. 16. The airport will refile its legal action, but a date is not yet certain.
“We’d also ask that concerned communities and counties representing citizens should file an amicus brief with the court once the Centennial Airport refiles its petition for review, to preserve and strengthen standing,” Olislagers said.
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