EA fails on Federally identified Noise Sensitive areas

The EA’s Noise Criteria fails when considering Section 4(f) properties and resources. Special consideration, such as cumulative impacts, needs to be given to noise changes in sensitive areas.

An Environmental Impact Statement (EIS) may be warranted to discuss noise impacts on sensitive sites.

The EA’s Noise Criteria doesn’t apply to Sensitive Areas.

FAA Order 1050.1E asks that special consideration be given to evaluating aircraft noise impacts on noise sensitive areas within national parks, national wildlife refuges and historic sites, including traditional cultural properties.  The FAA’s Draft Environmental Assessment (EA) identifies 3875 sensitive sites within the SoCal Metroplex that have increases between 1.5 – 5 dB DNL. The EA uses DOT Section 4(f) sites and lands which may qualify for this special consideration.[5]

Order 1050.1E continues: “..the DNL 65 dB threshold does not adequately address the effects of noise on visitors to areas within a national park or national wildlife refuge..” and further states that FAA Part 150 guidelines are also insufficient with these sites.

The order calls for a special consideration of these areas where “noise is very low and a quiet setting is a generally recognized purpose and attribute.” An alternate noise level or metric that would adequately address the noise effects needs to be used.[6] For example the St George EIS used Leq, Number of operations above 35dB and Time above Ambient as supplemental metrics.[7]

Cumulative effects of increases in noise must be evaluated.

Included in a special consideration should be evaluation of what impact the incremental increase in noise has on the total cumulative noise impacts of all airplane traffic [8]. Since some of these sites already have extremely low natural ambient noise levels of 25 dB [9] a “significant” threshold may have been reached.

Natural Ambient Noise

The EA Study area overlaid on National Park Service modeling of Natural Ambient Noise.  Ambient noise approaches 20dB (before human impacts)

The baseline of what measurement is a “quiet setting” must be defined. The existing DNL 60-65 dB and DNL 45 to 60 dB exposure level brackets don’t represent “quiet” and are orders of magnitude above ambient levels. A potentially suitable baseline the FAA should use as “quiet”, and the basis of measurements, is to use the per site existing ambient noise level.

The purpose of an EA is to decide whether an EIS is required. The Draft EA has four issues which must be addressed:

  1. Cumulative impacts of the incremental increases of noise from the proposed action must be considered and evaluated against a threshold.
  2. Changes in aircraft noise effects from DNL 65 dB from the proposed and no action alternatives need to be listed in a summary report which extends from DNL 65 dB to the lowest natural ambient noise level.
  3. The EA’s Noise Criteria needs to specify threshold values belowDNL 45 dB that describe how muchadditional noise isto be allowed. Suggested potential values are:
    1. 10 dB above natural ambient noise levels
    2. DNL 1.5 dB which follows the 65dB + (due to it being a sensitive area) or
    3. DNL 3 dB which follows the the 1990 EIS EECP determination about noise levels below DNL 65 dB.
    4. DNL 5 dB after the DNL 45-60 dB criteria.
  4. DNL has poor correlation to annoyance at lower levels (potentially as low as 0.5). A supplemental metric should be used to represent and communicate the effects of noise to the public. [6]

According to the results of the Section 4(f) properties and resources noise study, the Environmental Assessment has potentially significant indirect impacts in the form of noise where mitigation or a more detailed study may be required. There are: 3875 sites that have noise effect increases from DNL 1.5 dB up to DNL 5.0 dB. Use of added Metrics may help in the analysis and demonstration of the impacts.

Noise sensitive sites that receive an increase of 1.5 dB of noise or greater. [ Interactive map]

The below table is a selection of sites where the increase in aircraft noise level from the (OAPM’s) proposed changes exceeds DNL 5 dB. Attached as an appendix is a table of added sites where noise levels have exceeded DNL 1.5 dB.

Sensitive locations with Greater than 5dB DNL Increase in Noise
Protected Site NameArea (Acres)No Action in DNL dBProposed Action in DNL dBIncrease in DNL dB
Oakmont Park14.562733.26.2
Warrack Park31.9931.137.26.1
Avenue A Park0.2923296
Flag Hill Veterans Memorial Park7.822.828.86
Lillian Eaton Park0.4223.3295.7
John Tooker Civic Park4.4723.429.15.7
Oak Glen Creek Detention Basin18.2822.3285.7
Sorenson28.0927.533.25.7
Inman Family Trust19.429.635.25.6
Pablo Apis Park2.2925.530.95.4
Gates Canyon Park6.9435.240.65.4
Vail Ranch Park16.4325.731.25.4
Caroline Park18.3428.533.95.4
Paloma Del Sol4.4826.7325.3
Temecula Creek Trail Park4.5826.131.45.3
Clark/Tran37.4530.635.95.3
Hope Nature Preserve359.3831.236.55.3
Wildwood Canyon853.7923.428.75.3
Paseo Gallante Park1.6225.8315.2
Butterfield Stage Park2.5326.932.25.2
Upper Las Virgenes Open Space Preserve115.737.642.95.2
Steckel Park199.627.232.25.1
Emerson Wildlife Preserve-24.429.55.1
John Magee Park1.1226.931.85
Kent Hintergardt Park11.7126.231.25
Bryant St Detention Basin51.9322.427.55
5 Winds Ranch Open Space Preserve333.221.826.85
Ven-Tu Park-31.436.45

Table-B-ATAC_SoCal_Metroplex_Noise_Technical_Report-Above 1.5db

National Parks and Preserves, which have policies on soundscape management and controlling noise, are not included in the list of Section (4f) sites but should likewise be eligible for special consideration.

[5] Appendix A of the SoCal Metroplex Noise Technical Report, Section 4(f) of the Department of Transportation Act of 1966.
[6] Source FAA Order 1050.1E, Appendix A, Paragraphs 14.3, 14.4b.
[7] St. George Airport Environmental Impact Statement, FAA.
[8] Title 40 C.F.R. § 1508.7- Cumulative Impact., Grand Canyon Trust v. FAA (2002)
[9] Ambient noise levels must be considered in Noise Criteria, and NPS Geospatial sound modeling. 2013-2015. Project-2217356 http://www.nature.nps.gov/sound/soundmap.cfm