ARCHIVED REPORTS_2011_19 - Laserfiche WebLink

Home Browse Search

Forward Landfill LFG Acoustical Analysis Page 10 May 18, 2011 (9) Any activity whose regulation has been preempted by State or Federal law. (d) Acoustical Study. The Review Authority shall require the preparation of an acoustical study in instances where it has determined that a project may expose existing or proposed noise sensitive land uses to noise levels exceeding the noise standards specified in Table 9-1025.9. This determination shall be based on the existing or future sixty-five (65) dB Ldn noise contour in the General Plan, the proximity of new noise sensitive land uses to known noise sources, or the knowledge that a potential for adverse noise impacts exists. The study shall be paid for by the applicant and shall be prepared by a person or persons selected by the Director. The Director shall select the consultant from the County's consultant list. The acoustical study shall include the following information: (1) A general description of the project, with appropriate maps, and the noise sources of concern; (2) A description of the methodology that will be used to assess noise impacts, including a listing of all assumptions and data used in any computer models. (A) Computer models that will be used for noise predictions shall be standard versions approved by the FHWA, FAA, Caltrans, or other government agencies. (B) For traffic noise studies, the computer models, SOUND32 or other proprietary models based on the 1978 "FHWA Highway Traffic Noise Prediction Model (FHWA-RD-77-108)" shall be used. The FHWA's new "Traffic Noise Model" (TNM) shall be used after its phase in date. For aircraft noise studies, the latest version of the FAA's "Integrated Noise Model" (INM) shall be used. (C) If standard government approved models do not exist (e.g., railroad and industrial noise sources), a description of the model shall be provided. (3) A description of existing and future noise levels together with a comparison of these noise levels to the noise level standards specified in Table 9-1025.9. (4) Recommended mitigation measures to achieve compliance with the standards specified by Table 9- 1025.9 (i.e., noise barriers, site design, setbacks, equipment modification, structure sound proofing), or a detailed explanation stating why mitigation is infeasible. (e) Measurement. When noise level measurements are conducted, sound level meters meeting Type 1 (precision) or Type 2 (general purpose) sound level meter/microphone combinations shall be used. (1) Sound level meters shall be properly calibrated before use and used according to the manufacturer's instructions; (2) All measurements shall be in terms of A -weighted decibels using slow meter response, except for impulsive noise which shall be measured using fast meter response. (3) Measurements shall include sufficient sampling periods and locations to adequately describe local conditions and significant noise sources. (f) Prohibited Activities. The outdoor operation of any industrial, commercial, or residential property maintenance tool or equipment powered by an internal combustion engine or electric motor including, but not limited to, leaf blower, chainsaw, lawn mower, hedger, and vacuum cleaner is prohibited within 500 feet of a residence located in a residential zone between the hours of 9:00 p.m. and 8:00 a.m. (Ord. 3675; 3715; 3756; Ord. 4036 § 2 (part), 1999; Ord. 4141 § 2, 2002)