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Jerry Raney 31 March 2008 Page 2 approximately 500-feet east of the UPRR rail line. The noise environment is dominated by J local and distant traffic noise, as well as occasional train horns. We measured an average DNL of 55 dBA.3 We measured a typical maximum sound level of 82 dBA for train horns. RECOMMENDATIONS Interior Noise Levels Since the DNL noise level at the project site is below 60 dBA, no mitigation is needed to meet the City's interior DNL goal of 45 dBA. In order to meet the City's interior single-event noise goal of 50 dBA in bedrooms and 55 dBA in other habitable rooms, sound-rated windows, exterior doors and exterior walls aze necessary. We have summarized the STC4 ratings necessary to achieve the City's single-event interior noise goals in Table 1. Table 1: Minimum STC ratings for windows/doors and walls Lot Floor Room Windows/ Eat. Door Exterior Wall 3 1 _ _ Livinp/Dining Room_ _ 37 --_ 42 3 - 1 - - Kitchen ----- - - 37 42 3 --- 2 _ _ _ _ TV Room_---- .... 32 ---- 42 ---..-- 3 3 3 _ 2 2 2 Master Bedroom ----- Master Bathroom (No door) Master Bathroom (With door) 28 ----- 42 ------- 37 42 __32 ___ 42 3 3 2 2 Northwest Co_mer_Bedroom --- EastBedroom---- _37 _ 50 ---- 28 42 -~---- __ 4 - 1 _- -- Living/Dining Room---_ -__32 ------- 42 4_ 1 _ Kitchen - _--- 32 42 -_ 4- _ 2 _ TV/FamilyRoom __ 34 42 4 4 2 2 Master Bedroom _ MasterBathroom - 28 42 28 42 ___ 4 _ 2 _ ____ Northwest Corner Bedroom ____ _______ ____ 37 50 4 4 2 2 West Bathroom - ---North Bedroom ------- _ __ 37 42 --- 37 -- 50 ------- 6 6 _ 1 _2 _ Livin Dinin Room ___- ___ Master Bedroom 28 42 37 50 ___ 6 _ 2 _ ____ South Bedroom __ _ ___ 37 4 2 6 2 ____ Southeast Corner Bedroom _ _ __ _ _ __ __ 32 42 3 During the monitoring period, there was noisy street constmction occurring on Augustine Street on 16 Febmary and 19 Febmary; we have subtracted the constmction noise data from our measurement results. ` Sound Transmission Class (STC) - Asingle-figure rating standazdized by ASTM and used to rate the sound insulation properties of building partitions. The STC rating is derived from laboratory measurements of a particulaz building element and as such is representative of the maximum sound insulation. Increasing STC ratings correspond to improved noise isolation. Charles INI Salt e r A $ 8 O C 1 8 t @ S i A C 130 Sutter Slreel San Francisco Calllorma 9x104 Tel: 415 39l 0442 Fax: 415 39] 0454