SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSL. NOISE1.2 APPLICABLE NOISE REGULATIONSAlameda County and Santa Clara County noise standards that are pertinent to the AlamedaWatershed Management Plan are summarized below:! The Alameda County Noise Ordinance specifies standards for maximum allowable exteriornoise levels. These standards, applicable to non-transportation-related noise sources ingeneral, establish the maximum average exterior and interior noise levels to which thespecified noise-sensitive land use types may be exposed. These standards also establishthe maximum amount of time (in cumulative minutes per hour) that those land use typesmay be exposed to specified greater-than-average noise levels.! The Alameda County General Plan Noise Element sets out the County’s noise levelrequirements and states that construction noise should occur during times that are notnoise-sensitive (generally between 9 a.m. and 6 p.m., Monday–Friday). The noise elementalso presents the State Land Use Compatibility Guidelines, which recommend noiseexposure thresholds for different land use categories. For industrial uses, agriculture, golfcourses, and water recreation, noise levels up to 75 dBA (CNEL) are normally consideredacceptable. For playgrounds and neighborhood parks, noise levels up to 70 dBA (CNEL)are normally considered acceptable.! The Alameda County Zoning Ordinance sets performance standards with respect toexterior noise levels on industrial properties. Noise from industrial districts is not allowedto impact adjacent residential districts. The ordinance also places restrictions on noiselevels at quarries, and on home occupation noise within residential districts.! The Santa Clara County General Plan Health and Safety Element sets out the County’snoise level requirements and states that construction noise should be prohibited in areasthat exceed applicable interior and exterior standards (as defined by city/countyordinance), unless suitable mitigation measures can be implemented. The health and safetyelement also presents the State Land Use Compatibility Guidelines, which recommendnoise exposure thresholds for different land use categories. For open space andagriculture, noise levels up to 65 dBA (CNEL) are considered “satisfactory” and above65 dBA are considered “cautionary.” “Cautionary” noise levels are those which couldpose a threat to the proposed land use and for which additional study is required. No newland use proposed adjacent to an open space area is allowed to generate noise levels inexcess of the “satisfactory” limit of 65 dBA (CNEL). For parks, open space reserves, andwildlife refuges, the maximum noise level considered “satisfactory” is 55 dBA (CNEL),while higher noise levels are considered “cautionary.” Public buildings in parks and openspace areas must meet the noise standards listed under “Public or Semi-Public Facilities.”1.3 SENSITIVE RECEPTORSAccording to the Environmental Health and Safety Section of the Area Plan, noise-sensitive landuses include the following: residential development, mobile-home parks, motels and hotels,schools, libraries, churches, hospitals, nursing and convalescent homes, and some parks andcultural facilities. There are no noise-sensitive receptors within the Alameda Watershed, withthe exception of a few residences (e.g., SFPUC Watershed keeper cottages) and small enclavesNOP 96.223E: Alameda Watershed Management Plan III.L-2 ESA / 930385January 2001