A Letter To Fred Felleman re: Glide slope and noise monitoring

Mr. Felleman is a Commissioner of The Port Of Seattle. This letter is in response to a recent addition to the Port’s SAMP Near-Term Projects List, which was part of the Unanimous Consent Agenda (3c) Port Special Meeting in Kirkland, WA on 23 July 2019.

Dear Commissioner,

Thank you for adding in an update to the 34L antenna to your list of SAMP short-term projects at this week’s Special Meeting in Kirkland.

There’s one bit that is still missing from that plan which I believe is critical to its success: adding noise monitors south along the flight path as far as Federal Way.

As you know, there is currently no way to accurately predict how much of a noise reduction that change will have for residents. However, all the current studies seem to indicate that the improvements in perceived ‘annoyance’ increase as one gets farther and farther from the runway. In other words, the homes which will likely see the most benefit will be the ones farthest from the runway in Federal Way.

Unfortunately, the current permanent monitors do not extend out anything near far enough to be helpful in assessing the true effect of any change to the glide slope. What we need is a noise monitoring system in place before the antenna is updated. That way accurate noise measurements in Southern Des Moines and Federal Way can be taken to compare the results before and then after the change.

Without proper noise monitoring both before and after you change the glide slope, you will never be able to prove to the public that the system is functioning as intended. And, almost as important, you would be denying decision makers at other airports valuable data in determining whether or not making such a change will be efficacious for their airport communities. Since this is Federal money, measuring the efficacy of changing the glide slope is ultimately the concern of every U.S. citizen; not just people around Sea-Tac Airport.

For now, these monitors do not need to be permanent installations. Less expensive temporary monitors will do just as well, since they can be placed without long and expensive right-of-way issues. Again, the measurements are purpose-specific; arguments over permanent installations can be had on another day.

But for now I strongly urge you to bring this up with your fellow commissioners and your Noise Management team so that it may be added into the Near-Term Projects list.



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