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<br />Legacy Sunflower Apartments Page 76 <br />Mitigated Negative Declaration – March 14, 2019 <br /> <br />Section 18-314- Special Provisions. <br /> <br />The following activities shall be exempted from the provisions of this article: <br /> <br />(a) Noise sources associated with construction, repair, remodeling, or grading of any real property, <br />provided said activities do not take place between the hours of 8:00 PM and 7:00 AM on we ekdays, <br />including Saturday, or any time on Sunday or a federal holiday. <br /> <br />(i) Noise sources associated with the maintenance of real property, provided said activities take place <br />between 7:00 AM and 8:00 PM on any day except Sunday or a federal holiday, or between the <br />hours of 9:00 AM and 8:00 PM on Sunday or a federal holiday. <br /> <br />Standards of Significance <br /> <br />Noise impacts are considered to be significant if they expose people to noise levels greater than the <br />standards that are established in local general plans or noise ordinances. The exterior noise standard <br />for the City of Santa Ana multi-family residential uses is 65 dBA CNEL in usable outdoor space such as <br />backyards, decks, patios, etc. <br /> <br />Noise Modeling and Input <br /> <br />A worst-case construction noise scenario was modeled using a version of the Federal Highway <br />Administration’s Roadway Construction Noise Model (RCNM). The RCNM utilizes standard noise <br />emission levels for many different types of equipment and includes utilization percentage, impact, and <br />shielding parameters. <br /> <br />Federal Highway Administration (FHWA) Traffic Noise Prediction Model <br /> <br />Existing and Existing Plus Project noise levels along Sunflower Avenue, Flower Street, and other <br />affected nearby roadway segments were modeled utilizing the FHWA Traffic Noise Prediction Model <br />FHWA-RD-77-108 to quantify the project’s contribution to increases in ambient noise levels. <br /> <br />SoundPLAN <br /> <br />SoundPLAN acoustical modeling software was used to model the worst-case buildout traffic noise <br />impacts to the project residents. SoundPLAN also evaluates stationary noise sources (e.g., air <br />conditioning units, parking lots, etc.). SoundPLAN modeled traffic noise on Sunflower Avenue and <br />Flower Street. The roadway parameters that were used in the noise model included location, traffic <br />volume, speed and vehicle mix (autos, medium trucks, and heavy trucks). <br /> <br />Noise Impacts <br /> <br />Construction Noise <br /> <br />Construction noise represents a short-term impact on ambient noise levels. Existing noise-sensitive <br />land uses would be exposed to increased noise levels from construction activities at the project site. <br />The loudest noise during construction generally occurs during demolition and grading activities because <br />they involve the largest pieces of construction equipment. The maximum noise levels that are <br />generated by various types of construction equipment are shown in Table 17. The noise levels shown <br />in this table represent the maximum sound levels (Lmax), which are the highest individual sound that <br />6-98