What Are The Typical Noise Levels During Airplane Arrivals To SFO That Impact The People In Foster City
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FAQ - What Are The Typical Noise Levels During Airplane Arrivals To SFO That Impact The People In Foster City

Question: What are the typical noise levels during airplane arrivals to SFO that impact the people in Foster City?

Answer: As previously mentioned, landing traffic impact residents in Neighborhood 2 the most. Over-head airplanes at altitudes of about 1500-2000 feet will create single event noise levels in the range between 60 to 80 plus ?A? weighted dBA. The average level in a 24 hour day of about 70 dBA is typical. Single event levels of 70 dBA are generally considered by experts as ?moderately? loud. However, cumulative frequent exposures of these levels in the range of 400 events a day must be regarded as ?highly? annoyed. The measured community cumulative exposure number obtained by SFO Noise Abatement Offices shows an average CNEL of about 62. There is some issue as to how annoying 62 CNEL really is. FAA has the implicit official view that exposure to less than 65 CNEL is not unacceptable, and that majority of the population would considered exposure to this level as not highly annoyed. This author does not agree with FAA. Based on the experiences in many airports, and a limited survey of people in Neighborhood 2, 60-65 CNEL level exposures may be identified as ?highly annoyed?. In residential homes to the south-west of Foster City Blvd. where there are few direct over-flights (e.g. Pizarro Lane), the average single-event measured noise levels due to airplanes to the north east is slightly above 60 dBA which is about 10 decibels below that experienced in Neighborhood 2. The corresponding CNEL community level is about 50-55 range. This range is considered by EPA as quiet residential, but not in the ?very quiet? category. Although the ?averaged? noise level numbers in these areas of the City look more acceptable, the occasional short-cut fly-over at levels as high as 75-80 dBA do bring about some complaints.


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