Planning Commission recommends Noise Element amendment

An amendment to the county’s Noise Element was recommended for approval by the county’s Planning Commission August 25.

The recommendation will be sent to the Board of Supervisors, who must approve any general plan amendments including amendments to elements of the plan. The amendments do not change the interior or exterior noise limits but clarify standards for noise-sensitive land uses.

“It identifies the noise-sensitive areas that need to comply,” said Department of Planning and Land Use planning manager Joe Farace.

Under the current Noise Element, wherever possible noise-sensitive areas should not be subjected to noise above a Community Noise Equivalent Level of 55 decibels. If 60 decibels might be exceeded, an acoustical study is required, and if the study confirms that the level will be higher than 60 decibels the new development should not be approved unless modifications are made to reduce exterior noise to under 60 decibels or modifications are made to reduce interior noise to under 45 decibels along with a finding that social or economic considerations warrant project approval. Under no circumstances should a project which would exceed 75 decibels be approved. A noise-sensitive area is defined as any facility where quietness is an important attribute of the environment, including residences, hospitals, schools, hotels, resorts, libraries, or similar facilities.

Under the new ordinance, if the 60-decibel threshold is exceeded modifications shall be made which reduce the exterior noise to less than 60 decibels and the interior noise to less than 45 decibels, although an exception is still allowed for overriding social or economic considerations as long as the noise level is still below 75 decibels.

An exception for rooms usually occupied for only part of the day, such as schools or libraries, can have an interior one-hour average sound level due to outside noise of up to 50 decibels.

In addition to providing better definitions of the types of noise-sensitive land uses, the amendments define group usable areas and private usable areas for multi-family projects which contain both. Private usable open space is defined as open space intended for use of a single unit’s occupants such as yards, decks, and balconies while group usable open space is defined as areas intended for common use such as swimming pools, recreation courts, patios, open landscaped areas, and walkways. Group usable open space does not include off-street parking, loading areas, or driveways.

Exterior noise is defined for single-family dwelling units as noise measured at an outdoor living area adjoining and on the same lot as the dwelling and for all other projects as noise measured at all exterior areas provided for group or private usable open space purposes.