Federal Aviation Administration Environmental Prescreening Training Module 3 Noise Review

2 Federal Aviation Administration Noise Review June 25, 2013 Training Modules 1.NEPA and CEQ 2.FAA Order Air Traffic Environmental – Noise Review 4.Environmental Screening Process Overview

3 Federal Aviation Administration Noise Review June 25, 2013 Module 3 Air Traffic Environmental – Noise Review

4 Federal Aviation Administration Noise Review June 25, 2013 Guidance “Significant” Impacts - Noise Quantification of noise impacts

5 Federal Aviation Administration Noise Review June 25, 2013 Introduction Noise –What is noise? –Metrics used Impact Categories –What categories are examined for potential significant impacts? Noise sensitive Areas –What are these areas? –Why are they important?

6 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 One of the primary drivers for FAA air traffic environmental studies is the potential impact of noise. –Noise is defined as the presence of unwanted sounds –The basic unit is decibel (dB) –Noise measurements are logarithmic in nature –Most day-to-day sounds are between 30 and 100 dB. Normal conversation at 3 feet is about 65 dB An increase from 6dB to 10dB can be perceived as doubling loudness

7 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Typical Range of Outdoor Community Day-Night Average Sound Levels

8 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Several metrics are used to measure and express noise levels. –DNL: which is Day-Night Average Sound Level and is the most commonly used metrics. –Lmax: which is the Maximum A-Weighted Sound level –SEL: which is Sound Exposure Level or Single Event Noise Exposure Level. –Leq: which is Equivalent Sound Level –CNEL: Community Noise Equivalent Level. Only used in the state of California.

9 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Comparison of Different Sounds

10 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Relationship among Noise Metrics

11 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.)

12 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Levels for which speech intelligibility is impacted

13 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Addition of Two Decibel Levels

14 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Examples of Sound Level Averaging

15 Federal Aviation Administration Noise Review June 25, 2013 Noise 101 (Cont.) Percentage of Population Highly Annoyed by General Transportation Noise

16 Federal Aviation Administration Noise Review June 25, 2013 Noise Sensitive Areas and Significance An area where noise interferes with normal activities associated with its use. E.g.: Residential Specified areas within national parks National wildlife refuges Schools Places of worship Cultural and Historical sites

17 Federal Aviation Administration Noise Review June 25, 2013 Noise Sensitive Areas and Significance (Cont.) Noise from airplanes and helicopters, noise sensitive areas include such areas within the Day Night Level (DNL) 65 noise contour. An impact on noise levels of noise-sensitive areas is considered an extraordinary circumstance and requires additional environmental analysis.

18 Federal Aviation Administration Noise Review June 25, 2013 How Can We Identify Noise Sensitive Areas? Check various sources: (e.g., airnav.com) Check with local Airports District Office (ADO)

19 Federal Aviation Administration Noise Review June 25, 2013 How Can We Identify Noise Sensitive Areas? (Cont.)

20 Federal Aviation Administration Noise Review June 25, 2013 Impact Categories (Cont.) Take a few minutes to refresh on Noise section in E

21 Federal Aviation Administration Noise Review June 25, 2013 Impact Categories (Cont.) Noise For aviation noise analysis, the FAA has determined that cumulative noise exposure to individuals resulting from aviation activities must be expressed in terms of annual day/night average sound level (DNL) If significant noise impacts are expected, then detailed noise analyses must be performed.

22 Federal Aviation Administration Noise Review June 25, 2013 Impact Categories (Cont.) Noise A significant noise impact would occur if analysis shows that the proposed action will cause noise sensitive areas to experience an increase in noise of DNL 1.5 dB or more at or above DNL 65 dB noise exposure when compared to the no action alternative for the same timeframe.

23 Federal Aviation Administration Noise Review June 25, 2013 Quantification of noise impacts Guidance “Significant” Impacts - Noise

24 Federal Aviation Administration Noise Review June 25, 2013 Questions?