31B - CUP - 1901 NORTH FAIRVIEW ST

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City of Santa Ana Environmental Checklist and air conditioning (HVAC) equipment would be used to ensure that the interior spaces of the facility are comfortable for the occupants. The closest existing noise - sensitive land uses are the multi- family residential residences located to the south of the project site and the medical facility located to the north of the project site. HVAC units are expected to be located on the roof structures throughout the project site. HVAC units could be located as close as 100 feet from the closest existing noise- sensitive land use, The specific manufacturer and model of tile HVAC units have not yet been determined. However, these units will be selected with the relevant City and building standards as part of the performance specifications (i.e., acoustically engineered and tested by the manufacturer to ensure that the noise standards would not be exceeded). In addition, the direct view of the HVAC units will be screened by solid rooftop parapets (low walls), which would also provide effective acoustical as well as visual screening. As a result, noise from the project's HVAC equipment would be a less- than - significant impact. Parking Lot Activity Noise. Parking lot activity will contribute to onsite ambient noise levels through conversations, vehicle engines, car alarms, and doors slamming. The parking facilities will be located on the perimeter of the project site, as shown on Figure 2 -5, which is bound by an existing 6 -Foot wall that will remain. The existing wall will hinder the parking lot noise from traveling to the adjacent sensitive land uses. In addition, parking lot noise is short -term in duration. As a result, noise related to operation of the parking facilities is less than significant. Onsite Stationary Noise. Stationary onsite noise associated with the project will also include basketball courts that will be outside in the location of Building F during operation of Phase I of the project, The gymnasium (Building F) will be constructed during Phase It of the project. Noise from typical school basketball court activities are estimated to be 60 dBA Leq at a distance of 50 feet (ESA 2005)5. The closest sensitive receiver is approximately 150 feet from the basketball courts and will be screened visually and acoustically by the existing 6- foot -high concrete block wall. A noise level of 60 dBA would attenuate to 51 dBA Leq at a distance of 150 feet provided the receiver had direct line of site, which would be below the City's daytime (7:00 a.m. to 10:00 p.m.) noise standard for stationary sources. However, with the inclusion of a 6- foot -high block wall, noise levels would be further reduced a minimum of 5 decibels, to approximately 46 dBA Leq. Therefore, noise from the proposed basketball court will result in less- than - significant impacts. b. Exposure of persons to orgeneration of excessivegroundborne vibration orgr-oundborne noise levels? Less - than - Significant Impact. The Federal Transit Administration (FTA) has compiled typical vibration levels generated by construction equipment, which are commonly used as a reference for construction vibration level analysis. The vibration levels produced by construction equipment are outlined in Table 3 -19. Vibration levels from construction equipment attenuate as they radiate from the source. The equation to determine vibration levels at a specific distance states that PPVeQ„ tp = PPV,f x (25/D) ^1.5 where PPVrefis the Peak Particle Velocity at a reference distance of 25 feet, and D is the distance from the equipment to the sensitive receptor (Jones & Stokes 2004). 5 Environmental Science Associates. 2005, Noise Monitoring. January 18. The Academy Charter High School 3 78 June 2012 Initial Study /Mitlgated Negative Declaration tCf 00914.11