The FAA has released a portion of the noise impact results used in the Environmental Assessment. The data is on cultural resources identified by the Department of Transportation as potentially having noise sensitivity. It’s mostly parks, wildlife refuges, open spaces and historic sites – it’s called 4(f) data. The FAA also used modeled census block and grid-based noise impacts but they haven’t released it in data format. I’ve captured the 4(f) data from the EA and mapped it in an interactive format to help people better visualize the noise impacts.
There are 2 types of information: Overall Noise from aircraft, and the Change in Noise from the old flight paths to new. The noise is expressed in DNL dB units which (roughly) is an average of all noise over time.
a.) Here is a map of the overall db DNL levels using the proposed action. The dB represents just the noise from airplanes and doesn’t take into account any other ambient noises:
b.) Here is the map of the change in dB DNL (comparing the proposed action to they way it is now):
A dB DNL is difficult to subjectivify as we hear noise on a per plane basis – DNL is an aggregate.
The FAA didn’t release all the noise data. To evaluate the noise impacts, as well as the study methodology in regards to noise, they need to release the additional data. I requested it and they expressed to me that they weren’t sure if they should release as a Freedom of Information Act request, or as part of the EA.