Item 26 - Public Hearing Vista Heritage Charter School (601 North Fairview Street)

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Vista Charter Public Schools District Office and Outdoor Space Project CEQA Exemption 15183 random orientation of the crowd members.27 Therefore, crowd noise would be approximately 62 dBA at one meter from the source (i.e., the outdoor gathering areas). The nearest sensitive receptors would be the residential uses to the north of the project site, located approximately 200 feet from the proposed outdoor play areas. Therefore, crowd noise at the nearest sensitive receptor would be 26 dBA, which would not exceed the City's noise standards for residential uses in accordance with RR NOI-3 (i.e., 55 dBA for daytime and 45 dBA for nighttime) and would be lower than existing ambient noise levels of 51.1 dBA near the nearest sensitive receptors (residential uses to the north); refer to Table 7. As a result, noise generated from the outdoor play area would be further reduced. As such, project noise associated with outdoor play area would have a less than significant impact would occur in this regard. PROJECT -GENERATED VIBRATION IMPACTS Project construction activities can generate varying degrees of groundborne vibration, depending on the construction procedure and the construction equipment used. Operation of construction equipment generates vibrations that spread through the ground and diminish in amplitude with distance from the source. The effect on buildings located in the vicinity of the construction site often varies depending on soil type, ground strata, and construction characteristics of the receiver building(s). The results from vibration can range from no perceptible effects at the lowest vibration levels, to low rumbling sounds and perceptible vibration at moderate levels, to slight damage at the highest levels. Groundborne vibrations from construction activities rarely reach levels that damage structures. This evaluation uses the FTA architectural damage criterion for continuous vibrations of 0.3 in/sec PPV for engineered concrete and masonry. Typical vibration produced by construction equipment is illustrated in Table 10, Typical Vibration Levels for Construction Equipment. Table 10 Typical Vibration Levels for Construction Equipment Approximate peak particle velocity at Approximate peak particle velocity at Equipment 25 feet(inch/sec) 100 feet inch/sec) Large bulldozer 0.089 0.0111 Loaded trucks 0.076 0.0095 Small bulldozer 0.003 0.0004 Notes: 1. Calculated using the following formula: PPV equip = PPV ref x (25/D)f f where: PPV equip = the peak particle velocity in in/sec of the equipment adjusted for the distance PPV of = the reference vibration level in in/sec from Table 7-4 of the FTA Transit Noise and Vibration Impact Assessment Guidelines D = the distance from the equipment to the receiver Source: California Department of Transportation, Transportation and Construction Vibration Manual, April 2020. The nearest sensitive receptor structure is the existing single-family buildings located approximately 100 feet to the north of anticipated project site. As indicated in Table 10, vibration velocities from typical heavy construction equipment used during project construction would range from 0.0004 to 0.0111 in/sec PPV at 100 feet from the source of activity, which would not exceed the 0.3 in/sec PPV threshold. As such, the impacts would be less than significant. The proposed project use would not generate operational groundborne vibration that could be felt by surrounding uses. Additionally, the proposed project would not involve railroads or substantial 27 Ibid. Dec I y ouncil 26 — 108 1/16/20'2 e48