California Code of Regulations › Title 21 - Public Works › Division 2.5 - Division of Aeronautics (Department of Transportation) › Chapter 6 - Noise Standards › Article 1 - General › Section 5006 - Findings

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
Citizens residing in the vicinity of airports are exposed
					 to the noise of aircraft operations. There have been numerous instances wherein
					 individual citizens or organized citizen groups have complained about airport
					 noise to various authorities. The severity of these complaints has ranged from
					 a few telephone calls to organized legal action. Many of these cases have been
					 studied by acoustics research workers under sponsorship of governmental and
					 private organizations. These studies have generally shown that the severity of
					 the complaint is principally associated with a combination of the following
					 factors:
(a) Magnitude and duration of
				  the noise from aircraft operations;
(b) Number of aircraft operations;
				  and
(c) Time of occurrence during
				  the day (daytime, evening or night).
There are many reasons given by residents for their
					 complaints; however, those most often cited are interference with speech
					 communication, TV, and sleep. Numerous studies have been made related to speech
					 interference and hearing damage, and some studies have been made related to
					 sleep disturbance and other physiological effects. These studies provide
					 substantial evidence for the relationship between noise level and its
					 interference with speech communication and its effect relative to hearing loss.
					 Significantly less information is available from the results of sleep and
					 physiological studies.
In order to provide a systematic method for evaluating and
					 eventually reducing noise incompatibilities in the vicinity of airports, it is
					 necessary to quantify the noise problem. For this purpose, these regulations
					 establish a procedure for defining a noise impact area surrounding an
					 individual airport. The criteria and noise levels utilized to define the
					 boundaries of the noise impact area have been based on existing evidence from
					 studies of community noise reaction, noise interference with speech and sleep,
					 and noise induced hearing loss.
One of the fundamental philosophies underlying the
					 procedures in these regulations is that any noise quantity specified by these
					 regulations be measurable by relatively simple means. Therefore, these
					 regulations utilize as their basic measure the A-weighted noise level, which is
					 the most commonly accepted simple measure. To insure consistency between
					 criteria and measurement, the units for the criteria are also based on the
					 A-weighted sound level rather than one of the several more complex perceived
					 noise levels.
The level of noise acceptable to a reasonable person
					 residing in the vicinity of an airport is established as a community noise
					 equivalent level (CNEL) value of 65 dB for purposes of these regulations. This
					 criterion level has been chosen for reasonable persons residing in urban
					 residential areas where houses are of typical California construction and may
					 have windows partially open. It has been selected with reference to speech,
					 sleep and community reaction.
It is recognized that there is a considerable individual
					 variability in the reaction to noise. Further, there are several factors that
					 undoubtedly influence this variability and which are not thoroughly understood.
					 Therefore, this criterion level does not have a degree of precision which is
					 often associated with engineering criteria for a physical phenomenon (e.g., the
					 strength of a bridge, building, etcetera). For this reason, the state will
					 review the criterion periodically, taking into account any new information that
					 might become available.
1.
					 Renumbering and amendment of former Section
					 5006 to Section
					 5001, and renumbering and
					 amendment of former Section
					 5005 to Section
					 5006 filed 2-20-90; operative
					 3-22-90 (Register 90, No. 10). For prior history, see Register 79, No.
					 21.
Note: Authority cited: Sections
						21243
						and
						21669,
						Public Utilities Code. Reference: Air Transport Association of America v.
						Crotti (N.D.Cal. 1975) 389 F.Supp. 58.