General Plan Update - City of Inglewood

Chapter 6 Community Safety and Hazards
Development, minimum noise insulation standards must be achieved (24 CFR Part 51,
Subpart B).
The FAA has prepared guidelines for acceptable aircraft noise exposure in its Federal
Aviation Regulation (FAR) Part 150 Noise Compatibility Planning Program. According
to Part 150 guidelines, exterior aircraft exposures of 65 dBA CNEL or less and an interior
exposure 45 dBA CNEL or less are considered acceptable for residential uses. 126 The
FAR Part 150 Noise Compatibility Planning Program also provides funds for noise
abatement in impacted areas. For a city to obtain noise abatement funds, FAA requires
that local authorities provide evidence that they are preventing the introduction of new
noise sensitive uses within noise impact areas. This policy is intended to encourage the
promulgation and enforcement of local land use compatibility measures.
State Regulations
The Sate of California Governor’s Office of Planning and Research has published
recommended guidelines for the preparation and content of the Noise Element of a
General Plan. Each jurisdiction is required to consider these guidelines when developing
the General Plan Noise Element and determining acceptable noise levels within the
community. The purpose of the Noise Element is to limit the exposure of the community
to excessive noise levels. A noise element must identify and appraise noise problems in
the community by analyzing and quantifying current and projected noise levels for all
stationary and mobile noise sources in the community. Noise contours are then
developed and shown for all the noise sources in the community, and are eventually used
as a guide for establishing a pattern of land uses that minimizes the exposure of
community residents to excessive noise.
Title 24 of the California Code of Regulations includes Sound Transmission Control
requirements that establish uniform minimum noise insulation performance standards for
new hotels, motels, dormitories, apartment houses, and dwellings other than detached
single-family units. Specifically, Title 24 states that interior noise levels attributable to
exterior sources shall not exceed 45 dBA CNEL in any habitable room of new dwellings.
Dwellings are to be designed so that interior noise levels will meet this standard for at
least ten years from the time of building permit application.
The State Department of Health Services has adopted guidelines for use in assessing the
compatibility of various land use types with a range of noise levels. These guidelines are
presented in Table 6.9-4. As an example, an exterior noise level up to 65 dBA CNEL is
“normally acceptable” for multi-family residential uses, without special noise insulation
requirements. A noise level of 65 to 70 dBA CNEL or more is identified as "conditionally
acceptable" for multi-family residential uses. Under the “conditionally acceptable”
category, an analysis of the noise reduction requirements is required and noise insulation
126 Although the noise standards identified by the FAA are based on L dn levels, CNEL is used in this
Analysis. CNEL and L dn rarely differ by more than one dBA.
6.9-14
City of Inglewood General Plan Update Technical Background Report