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Table N-1: Reference Noise Levels <br />Noise Source Duration <br />(hh:mm:ss) <br />Ref. <br />Distance <br />(Feet) <br />Noise <br />Source <br /> Height (Feet) <br />Hourly <br />Activity <br />(Mins)7 <br />Reference Noise <br />Level (dBA L50) <br />@ Ref. Dist. @ 50 Feet <br />Roof-Top Air Conditioning Unit1 96:00:00 5' 5' 39 74.4 54.4 <br />Trash Enclosure Activity2 00:00:32 5' 5' 60 69.0 49.0 <br />Pad-Mounted Transformer3 -3 6' 5' 60 56.0 37.6 <br />Parking Lot Vehicle Movements4 01:00:00 10' 5' 60 44.0 33.5 <br />Courtyard Activity5 00:08:00 10' 4' 60 73.8 59.8 <br />Outdoor Pool/Spa Activity6 00:10:00 5' 4' 60 68.7 48.7 <br />Roof-Top Parking4 00:10:00 5' 4' 60 68.7 48.7 <br />Source: Urban Crossroads, 2019. Attachment A. <br />1 As measured by Urban Crossroads, Inc. on 7/27/2015 at the Santee Walmart located at 170 Town Center Parkway. <br />2 As measured by Urban Crossroads, Inc. on 5/3/2018 at a commercial and office park trash enclosure in the City of Costa Mesa. <br />3 Source: NEMA TR 1-2013 Transformers, Step Voltage Regulators and Reactors, Table 2 sound level for a 500 kVA transformer. <br />4 As measured by Urban Crossroads, Inc. on 8/24/2016 in the parking lot of the Windemere Apartment community in the City of Riverside. <br />5 As measured by Urban Crossroads, Inc. on Saturday night, September 21, 2019 in the City of Newport Beach. <br />6 As measured by Urban Crossroads, Inc. on 7/5/2017 at the Covenant Hill Clubhouse pool in Ladera Ranch. <br />7 Anticipated duration (minutes within the hour) of noise activity during typical hourly conditions expected at the Project site based on the <br /> reference noise level measurement activity. <br />Table N-2 identifies that the operational noise from the Project would range from 31.4 to 46.9 dBA Lā‚…ā‚€ at the sensitive <br />off-site receiver locations. These operational noise level calculations are based on the reference noise level <br />measurements in Table N-1 and include barrier attenuation provided by intervening structures between each noise <br />source and the receivers, which are shown in Figure 15. These noise levels also assume the worst-case with the roof- <br />top air conditioning units, trash enclosure activity, pad-mounted transformers, parking lot vehicle movements, outdoor <br />courtyard activity, outdoor pool/spa activity and roof-top parking activities all operating simultaneously. In reality, the <br />noise sources would most likely not occur simultaneously and would vary throughout the day. <br /> <br />Table N-2: Project Operational Noise Levels <br />Receiver Location Noise <br />Source <br />Project Operational Noise Levels (dBA) <br />L50 (30 mins) L25 (15 mins) L8 (5 mins) L2 (1 min) Lmax (<1 min) <br />R1 <br />Air Conditioning Unit (Roof-Top) 15.6 17.3 18.6 18.9 19.4 <br />Trash Enclosure Activity 27.7 33.7 40.7 45.7 47.2 <br />Pad-Mounted Transformer 14.8 0.0 0.0 0.0 0.0 <br />Parking Lot Veh. Movements 20.4 23.4 31.4 37.4 45.0 <br />Courtyard Activity 36.8 39.0 41.5 43.9 46.6 <br />Outdoor Pool/Spa Activity 28.1 31.1 34.4 37.5 42.9 <br />Roof-Top Parking 9.4 12.4 20.4 26.4 34.0 <br />Combined Noise Level: 37.9 40.7 44.8 48.7 51.8 <br />R2 <br />Air Conditioning Unit (Roof-Top) 20.7 22.4 23.7 24.0 24.5 <br />Trash Enclosure Activity 13.4 19.4 26.4 31.4 32.9 <br />Pad-Mounted Transformer 28.0 0.0 0.0 0.0 0.0 <br />Parking Lot Veh. Movements 32.4 35.4 43.4 49.4 57.0 <br />Courtyard Activity 42.3 44.5 47.0 49.4 52.1 <br />Outdoor Pool/Spa Activity 31.6 34.6 37.9 41.0 46.4 <br />Roof-Top Parking 14.4 17.4 25.4 31.4 39.0 <br />Combined Noise Level: 43.2 45.4 49.0 52.8 58.6 <br />R3 <br />Air Conditioning Unit (Roof-Top) 22.4 24.1 25.4 25.7 26.2 <br />Trash Enclosure Activity 14.4 20.4 27.4 32.4 33.9 <br />Pad-Mounted Transformer 24.7 0.0 0.0 0.0 0.0 <br />2-159