F-22 Plus-Up Environmental Assessment - Joint Base Elmendorf ...

F-22 Plus-Up Environmental Assessment
4.0 Environmental Consequences
communities. The plus-up of six F-22 aircraft with the corresponding increase in base
employment would not impact base or off-base recreational opportunities.
4.8.2 Training Airspace Environmental Consequences
F-22 training in Alaska airspace with the proposed increase of six primary aircraft would be
similar to the existing use by F-22 aircraft. An approximate 16.7 percent increase in sortieoperations
is anticipated under the Proposed Action. There would be no reason to believe that
such an increase of F-22 training would affect land use or recreation beneath the training
airspace. The potential to affect land use or recreation under the airspace is slight.
Under the Proposed Action, subsonic noise would increase slightly over baseline conditions
(refer to Section 4.2.2). Most annual average noise levels are expected to remain below 45 dB
L dn. Where noise levels are higher than 45 dB L dn, they are expected to increase by 1 dB or less
(Table 4.2-3) under the Proposed Action over existing conditions. The USEPA has identified an
annual average noise level of 55 dB L dn as a level to begin assessing the potential for noise
impacts. Under the Proposed Action, noise levels beneath all training airspace units except
Eielson and Viper MOAs would be below 55 dB L dn. Noise levels beneath Eielson and Viper
MOAs would increase by 1 dB to 59 dB L dn and 57 dB L dn, respectively. Noise level changes of 1
dB are effectively indiscernible. With noise levels below 55 dB L dn, or minimally changed
throughout, there would be no anticipated effect on land use patterns, ownership, or
management practices under military training airspace.
Under the center of Stony A/B MOAs, Section 4.2.2 shows that the number of sonic booms
would increase from 18.1 sonic booms per month (one boom per 1.7 days) to 21.5 sonic booms
per month (one boom per 1.4 days). Under the Naknek MOAs, the number of sonic booms
would increase from an average of 1.5 per month (one boom per 20 days) to an average of 1.7
per month (one boom per 17 days) (see Table 4.2-2). Residents or long-term visitors could
experience more sonic booms as a result of the increase in supersonic activities. The increase in
supersonic activity could be perceived in isolated areas as an unwanted intrusion, and persons
could be annoyed. The increased number of sonic booms would not be expected to impact
management goals for special use areas under the MOAs.
Detected sonic booms have the potential to cause increased disturbance in recreational, hunting,
or fishing areas. Under most airspaces, it is unlikely that any occasional visitor or hunter would
discern the difference between the current number of sonic booms and the increased number
associated with an F-22 plus-up. Individuals who spend extensive time subsistence hunting
and fishing under some MOAs could discern an increase. The increased frequency of sonic
booms would not be expected to affect land use or land use patterns, ownership, or
management, but the increase could result in personal annoyance.
A number of Alaska Native villages and traditional subsistence areas underlie Alaskan SUA.
Alaska Natives have expressed concern that existing and projected noise levels and sonic booms
could affect recreational uses, as well as traditional hunting activity. In addition to being
important social and cultural activities, the local economy is often dependent on subsistence
activities. As noted above, average noise level increases under the MOAs are not expected to be
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