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5.7 NOISE on all projects licensed by the CEC,the LEC project will develop a Hearing Protection Plan, which complies with California Occupational Safety and Health Administration (Cal-OSHA) requirements. This Hearing Protection Plan will be incorporated into the project construction Health and Safety Plan. The plan will require appropriate hearing protection for workers and visitors throughout the duration of the construction period. 5.7.3.3 Operational Impacts 5.7.3.3.1 Worker Exposure Nearly all components will be specified not to exceed near-field maximum noise levels of 90 dBA at 3 feet (or 85 dBA at 3 feet where available as a vendor standard). Because there are no permanent or semi-permanent workstations located near any piece of noisy plant equipment,no worker's time-weighted average exposure to noise should routinely approach the level allowable under Occupational Safety and Health Act of 1970 (OSHA) guidelines. Nevertheless, signs requiring the use of hearing protection devices will be posted in all areas where noise levels commonly exceed 85 dBA, such as inside acoustical enclosures, and the project will comply with applicable Cal-OSHA requirements. A current hearing conservation program is currently in place at the STIG facility. An identical program will be put in place at the LEC location as workers will be shared between the two plants. Outdoor levels throughout the plant will typically range from 90 dBA near certain equipment to roughly 65 dBA in areas more distant from any major noise source. Therefore, noise impacts to workers during operation will be less than significant. 5.7.3.3.2 Transmission Line and Switchyard Noise Levels One of the electrical effects of high-voltage transmission lines is corona. Corona is the ionization of the air that occurs at the surface of the energized conductor and suspension hardware due to very high electric field strength at the surface of the metal during certain conditions. Corona may result in radio and television reception interference, audible noise, light, and production of ozone. Corona is generally a principle concern with transmission lines of 345 kilovolt (kV) and higher. Noise is also generally associated with foul weather conditions. As stated in Section 3.0,Electric Transmission,the new transmission line will only extend from LEC to the existing STIG switchyard. Because of the transmission lines close proximity to the interconnection,the 230-kV transmission system and the large distance to the nearest receptors it is expected that no corona-related design issues will be encountered. 5.7.3.3.3 Plant Operational Noise Levels A noise model of the proposed LEC facility has been developed using source input levels derived from manufacturers' data and field surveys of similar equipment. The noise emissions from the plant have been calculated at the residential receptors of potential concern. The noise levels presented represent the anticipated steady-state level from the plant with essentially all equipment operating. Standard acoustical engineering methods were used in the noise analysis. The computer software noise model, CADNA/A by DataKustik GmbH of Munich,Germany,is very sophisticated and is capable of fully modeling very complex industrial plants. The sound propagation factors used in the model have been adopted from ISO 9613-2 Acoustics-Sound Attenuation During Propagation Outdoors and VDI 2714 Outdoor Sound Propagation. The model divides the proposed facility into a list of individual point and area noise sources 5.7-14 SAC/371322/082330005(LEC_5.7_NOISE.DOC)