75D - PH ZONING ORD AND CUP CALIFORNIA PALMS

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1.0 BACKGROUND 1 This noise analysis, conducted as a componem of the environmental review process under the California Environmental Quality Act (CEQA), codified in Section 21000 et seq. in the Public Resources Code, examines the potential noise impacts resulting from the issuance of a caning change and conditional use permit for the ' conversion of the existing California Palms Motel to the subs Transieut/Residemial Hertel (extended stay) facitity. The site is located at 01 South Harbor Boulevard in the City of Santa Ana, California. The City has determined that its support for the proposed project will be based on whether the project meets the provisions of City Otdiaance No. NS-2471 and the design and development standards for transienUresidential hotels as adopted by the City Council on May 21, 2001. For clarity and ease of the reader and subsequent integration into the City's records, this document follows the CEQA format used in the preparation of Mitigated Negative Declarations. 1 The analysis finds that site operations would not significantly raise ambient noise levels nor would they expose site occupants to exterior noise levels in excess of the City or State standards, However, due to the proximity of Harbor Boulevard, the pmject is located in an area of elevated noise and Interior noise levels have been measured to be in excess of the State's interior noise standards for multi-family residential development. The analysis then includes mitigation in the form of noise insulation measures to reduce these interior noise levels to less than the State standard thereby reducing the impact to less than significant. 2.0 EXISTING ENVIRONMENT 2.1 Noise Definitions Sound is a pressure wave transmitted through the air. It is described in terms of loudness or amplitude (measured in decibels), frequency or pitch (measured in Hertz [Flz] or cycles per second), and duration (measured in seconds or minutes). The standard unit of measurement of the loudness of sound is the decibel (dB). Typical human (rearing can detect changes in sound levels of approximately 3 d$ under normal conditions. Changes of 1 to 3 dB are detectable under quiet, controlled conditions and changes of less than 1 dB aze usually indiscernible. A change of 5 dB is typically noticeable to most people in an exterior enviromment whereas a change of 10 dB is perceived as a doubling (or halving) of the noise. The human ear is not equally sensitive to all frequencies. Sound waves below 16 Hz are not heard 'tit all and are "felt" more as a vibration. Similarly, while people with extremely sensitive hearing can hear sounds as high as 20,000 Hz, most people cannot heaz above 15,000 Hz. In all cases, hearing acuity falls off rapidly above about 10,000 Hz and below about 200 Hz. Since the human ear is not equally sensitive to sound at all frequencies, a special frequency dependent rating scale is usually used to relate noise to human sensitivity. The A-weighted decibel scale (dBA) performs this compensation by discriminating against frequencies in a manner approximating the sensitivity of the human ear. Noise is defined as unwanted sound, and is larown to have several adverse effects on people, including hearing loss, speech and sleep i~erference, physiological responses, and annoyance. Based on these (mown adverse effects of noise, the federal governmem, the State of California, and many local governments have established criteria to protect public health and safety and to preverrt dismption of certain human activities. Noise may be generated from a poim source, such as a piece of construction equipment, err from a line source, such as a road containing moving vehicles. Because noise spreads in an ever-widening Pattern, the given amoum of noise striking an object, such as an eazdnun, is reduced with distance from the source. This is known as "spreading loss." The typical spreading loss for point source noise is 6 dBA per doubling of the distance from the noise source. A line source of noise, such as vehicles proceeding down a roadway, will also be reduced with distance, but the rate of reduction is a function of both distance and the type of terrain over which the noise passes. Hard sites, such as developed areas whir paving, reduce noise at a rate of 3 dBA per doubling of the distance while soft sites, such as 75D-121