If you live in the area, you may hear about ‘Noise Boundary Maps’. These are maps with a boundary drawn showing the furthest extent of the DNL65. Your residence must be within this boundary in order to be eligible for ‘The Port Package’, ie. insulation and triple-pane windows. (However, there are other criteria discussed in the topics Avigation Easements and DNL65.)
This is the 2013 boundary, taken from the most recent Part 150 Study by Landrum & Brown:
Here is that same 2013 boundary from the same study along with the projected 2018 boundary:
Projected 2021 Boundary
And here is the projected 2021 boundary taken from the October 11, 2016 Airport Noise Insulation Project briefing:
This entire document should be studied thoroughly as this provides almost the entire set of Port talking points on what they feel they have done for the community and how they view their relationship to us. But for now, take a look at pages seven and eight. They make the outrageous claim that the Noise Boundary will actually decrease over time because ‘aircraft are getting so much quieter’!
Finally, there are several plots in this portion of the Part 150 Study and the entire document is worth studying because it provides several different ways to define ‘noise’ scientifically.