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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 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 ratinQS for windows/doors and walls Windows / Lot Floor Room Eat. Door Exterior Wall 3 1 --- .--Living/Dinin~ Room ---"-'--- --._37 _.-..------------ 42 3 I Kitchen .-...-..-.-..-. 37 42 3 2 TV Room 32 42 3 2 Master Bedroom 28 42 3 2 Master Bathroom (No door) 37 42 __ 3 __ ----- -- 2 Master Bathroom (With door ---- - 32 42 ------------------- 3 2 Northwest Comer Bedroom ------------- 37 50 3 2 East Bedroom 28 42 4 1 LivinB/Dining~ Room_ _ 32 42 4 ------- 1 ------- Kitchen -- - 32 42 __ 4 2 __ ------- TV/Fami~Room ---------------- _ 34 42 4 2 Master Bedroom - - 28 42 4 2 Master Bathroom 28 42 4 ----- -- 2 --_ -- Northwest Comer Bedroom --------- 37 50 - 4 2 Wes[Bathroom 37 42 - _ 4 2 North Bedroom 37 50 - --6--- -__.-1....._..._ .-...-.-..------ Livin~/Dining Room .-------- 42 ------.... 28- - 6 2 Master Bedroom ---.-._...-._ ---- - ---- -- 37 50 6 ----------- 2 -------------- South Bedroom ------ ----------------- 37 42 ---- - 6 2 Southeast Corner Bedroom - 32 42 3 During the monitoring period, there was noisy street construction occurring on Augustine Street on 16 February and 19 Febmary; we have subtracted the construction noise data from our measurement results. ° Sound Transmission Class (STC) - Asingle-figure rating standardized 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 M Salter Associates Inc Sao swier street say Franrisdo caemroia saio° .ec °is ss~ o°°z Fa.: °is aw oosa