Laserfiche WebLink
JCC Tri-Valley Preschool Outdoor Play Area Noise <br /> 30 January 2017 Page 3 <br /> The ambient noise measurement results are summarized in Table 1. <br /> Table 1.Ambient Noise Level Summary <br /> Measurement Typical Typical Daytime Average <br /> Location DNL(dB) Noise Level(Leg,dB) <br /> LT1 67 66 <br /> 512 54* 53 <br /> ST3 52* 51 <br /> 5T4 51* 51 <br /> *Note:These DNL values are estimated based on the long-term data and the shat-data at the offset location. <br /> NOISE FROM CHILDREN PLAYING <br /> We recently measured average noise levels at a related preschool outdoor play area in San Francisco. <br /> Based on that measurement,we found that noise from playing children in a similar environment is <br /> approximately 68 dB at a distance of 15 feet.There were 18 children in the play area during this <br /> measurement. <br /> Based on the landscape drawing(Sheet L-1)we received,the play area would be approximately <br /> 70 feet from the nearest neighboring residential property line(near Location ST4). With 25 children <br /> playing,we estimate the average noise level would be approximately 56 dB at this area of the property <br /> line. At 100 feet away, near Location ST2,the noise from children would be approximately 53 dB. <br /> These levels do not include any noise reduction factors for any fencing(including the existing fence). <br /> ANALYSIS&RECOMMENDATIONS <br /> We evaluated the expected noise from children two ways,as follows: <br /> Land-Use Compatibility(City General Plan) <br /> The City Noise Element of the General Plan addresses noise using DNL levels to assess land-use <br /> compatibility. Based on the estimated noise level from children playing,we calculate the expected <br /> future DNL at the neighboring residential property lines.The City land-use compatibility standard for <br /> residences,the measured typical ambient noise on-site, and the calculated"ambient+children"noise <br /> Acoustics are summarized in Table 2 for comparison. <br /> Audiovisual <br /> Telecommunications Table 2. Land-Use CompatibilitySummary Comparison(DNL,dB) <br /> Security <br /> Residential City Land-use Typical Calculated Level Calculated Level <br /> Property Near Each Compatibility Measured with Children with Children <br /> Measurement Standard Ambient Playing for Playing for <br /> 130 Sugar Shoot Location 3 hours 8 hours <br /> F oar 5 <br /> soil F,anauo CA ST2 54 54 55 <br /> 94104 ST3 60 52 52 54 <br /> T 415 3970442 ST4 51 52 54 <br /> F 4 1 5 3970454 <br /> m»uns<3.:cr cam <br /> Salter <br /> soCuT[s INC <br />