DCA Airplane Assessment Study Concludes
The DC Department of Energy and Environment (DOEE) hosted a public meeting September 20th to provide a summary of a two-year long assessment of aircraft noise on the District. Randy Waldeck, an acoustic engineer with CSDA Design Group, provide an overview of the just completed study. There were several important take-aways from the meeting:
· The changes the FAA made to flights paths of departing and arriving planes to Ronald Reagan National Airport (DCA) in 2015 increased noise by around 2 dB in communities along the Potomac river including Georgetown to the low 60’s dB, the level of loud speech. The resulting total noise when averaged over a long period did not meet the FAA’s 65 dB DNL (Day Night Level) standard of when noise is considered to have a significant impact. While an individual plane may sound like a rock band going overhead and interfere with speech and sleep it is the average dB per day over a year that the FAA measures.
· The school measurements showed that several class rooms did not meet ANSI classroom noise criteria established to ensure exterior noise did not interfere with a good learning environment. Noisy class rooms have been shown to impede learning.
· The residential measurements showed that the sound levels in bedrooms were high enough to awaken 12-33% of the population, depending on location. Randy explained that the results are a probability percentage because sound sleepers might not be awakened by the noise levels in those residences, while light sleepers might be.
· Approximately 400 flights per day from DCA produce noise in northwest DC at or above the 65 dB level which can interfere with normal speech and hearing outside.
· The FAA has performed an extensive study of aircraft noise, its impact on communities, and the adequacy of the current 65 dB DNL standard. The study was completed two years ago but has not been released by the FAA. If released it may require the FAA to reevaluate its 65dB DNL standard.
· The study contains a number of suggestions for noise mitigation including revising the North Flow departure, reducing North Flow flights from nearly 70% to 50%, climbing faster after departure, and revising approach procedures in South flow.
· Marcio Duffles, the Ward Three Representative to the DCA Working Group, and ANC2E commissioner Rick Murphy, the Ward Two Representative, explained the purpose and activities of the Working Group. Marcio mentioned that considerable progress had been made on the South Flow approach, but the recent suit by the state of Maryland had caused progress to halt. Rick mentioned that the Working Group can only make recommendations to the FAA and a recommendation to change the North Flow departure flight path had received no response from the FAA to date.