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Home My WebLink AboutRS130181_Acoustical AnalysisZWv\ l PLANNING DEVELOPMENT SERVICE DEPARTMENT/ ACOUSTICAL AND BUILDING PERMIT P.O. BOX 4048, SANTA ANA, CA 92702 TEL, 714/ 834-2978 FAX 79"252 Acoustical Report No. 543401 -0 100 Submitted Pursuant to Conditional No's Acoustical Consultant Mestre Greve Associates Project Address or Tract No. 29 Avalon Vista ( ) No report is necessary. This project will satisfy all Orange County noise exposure limits without further analysis. 9x lanatlon: This submittal is for. {✓) Tentative Tract /Parcel Map {✓) Preliminary Grading (✓) Precise Grading {✓) Recordation Map (✓) Issuance of Building Permit Mitigation Measures: { } Earth Berming ( ) Freestanding Soundwall ( ) Patio or Balcony wails (✓) Mechanical Ventilation's ( ) Windows Upgrade { ) Others: Complete this form and attach the following: ( 2) - Report copies with full calculations, data's & attached drawings. { 1) - Copy of Architectural building site plan, showing the entire tract & roadways. Drawing size: Scale 118" = V- 0" max. and reduce to 11" X 17" print & folded In 8 1/2" X 11 ". { 1) - Copy of precise grading plan showing the entire tract & roadway grade elev. & bldg. pad elevations. Drawing size: Scale 1 "= 40' max. & reduce to half size (§ 11' X 17" print & folded in 8 1/2" X 114. Applicant Name: Tel. no. Fax no. Submitted By: Tel. no. Fax no. For County Use Only Statement Of Acoustical Consultant Notation Date JBy Remarks Al Information and calculation contained herein are true and correct to the best of my knowledge. The project is designed to meet existing acoustical requirements as determined by the County of Orange. I have supervised the preparation of this noise study and i am an Orange County Certify Acoustical Consultant. Signature: l e Q Cie- t.- Date.5-8-13 Received Accepted Received Received Approved JL Notes & Comments: For questions or additional information contact Mike Holritz at Mestre Greve Associates ACOUSTICAL ANALYSIS REPORT EXHIBIT V-I V-9 Noise Analysis for 29 Avalon Vista County of Orange, California Project #543401-0100 May 8, 2013 Prepared For; Pelican Developers, Inc. 25 Timberland Aliso Viejo, CA 92656 Prepared By: Fred Greve, P.E. Mike Holritz, 1NCE Mestre Greve Associates Division of Landrum & Brown 27812 El Lazo Road Laguna Niguel, CA 92677 949-349-0671 MHMestre Greve Associates 29 Avalon Vista Division of Landrum & Brown Project #543401-0100 SUMMARY NOISE ANALYSIS FOR 29 AVALON VISTA COUNTY OF ORANGE EXTERIOR NOISE LEVELS Rear yards will be exposed to noise levels of about 58.7 CNEL. This is far less than the County's 65 CNEL noise standard. Therefore noise barriers will not be needed Any balconies would also be exposed to noise levels of far less than 65 CNEL. Therefore, balcony barriers will not be required. INTERIOR NOISE LEVELS Exterior building surfaces at the home will be exposed to noise levels of far less than 65 CNEL, and therefore will require less than 20 dB exterior to interior noise reduction in order to meet the City's 45 CNEL interior noise standard. With construction practices common in California, residential buildings achieve outdoor to indoor noise reductions of at least 20 dB. Therefore, all rooms are projected to meet the City's 45 CNEL interior noise standard without building upgrades. ADEQUATE VENTILATION Since the noise attenuation of a building falls to about 12 dB with windows open, buildings exposed to noise levels greater than 57 CNEL will meet the 45 CNEL interior noise standard only with windows closed. In order to assume that windows can remain closed to achieve this required attenuation, adequate ventilation with windows closed must be provided per the applicable California Building Code. Since the noise exposure is projected to be about 58.7 CNEL, adequate ventilation will be required for this home. Page 1 of 6 Mestre Greve Associates 29 Avalon Vista 6 a Division of Landrum & Brown Project #543401-0100 NOISE ANALYSIS FOR 29 AVALON VISTA COUNTY OF ORANGE 1.0 INTRODUCTION The purpose of this report is to demonstrate compliance of 29 Avalon Vista with the noise related `Conditions of Approval' placed on the project by the County of Orange. The project calls for the development of one custom single-family home. The project is located in the Newport Coast area of the County of Orange, as shown in Exhibit 1. The site plan is shown in Exhibit 2. The project is near Newport Coast Drive. All other roadways in the project vicinity are collectors, and will not have a significant noise impact on the project. This report specifies any mitigation measures necessary to meet the 65 CNEL exterior noise standard and the 45 CNEL interior noise standard. Site plan and grading information was obtained from the "Architectural Site Plan for Lot 19, Pelican Crest II, 29 Avalon Vista" by Richard Krantz Architecture, February 21, 2013. 2.0 COUNTY OF ORANGE NOISE STANDARDS The County of Orange specifies outdoor and indoor noise limits for residential land uses. Both standards are based upon the CNEL index. CNEL (Community Noise Equivalent Level) is a 24- hour time -weighted annual average noise level based on the A -weighted decibel. A weighting is a frequency correction that correlates overall sound pressure levels with the frequency response of the human ear. Time weighting refers to the fact that noise that occurs during certain noise - sensitive time periods is given more significance because it occurs at these times. In the calculation of CNEL, noise occurring in the evening time period (7 p.m. to 10 p.m.) is weighted by 5 dB, while noise occurring in the nighttime period (10 p.m. to 7 a.m.) is weighted by 10 dB. These time periods and weighting factors are used to reflect increased sensitivity to noise while sleeping, eating, and relaxing. The County of Orange has adopted an exterior noise standard of 65 CNEL for an observer located in the rear yards. In addition, the City uses an interior noise standard of 45 CNEL. Page 2of6 Mestre Greve Associates Mes Division of Landrum & Brown Exhibit 1 I Vicinity Map Newport Coast Drive MbaMestre Greve Associates Division of Landrum & Brown Exhibit 2 Site Plan MWMestre Greve Associates Division of Landrum & Brown 3.0 METHODOLOGY 29 Avalon Vista Project #543401-0100 The traffic noise levels projected in this report were computed using the Highway Noise Model published by the Federal Highway Administration ("FHWA Highway Traffic Noise Prediction Model", FHWA-RD-77-108, December 1978). The FHWA Model uses traffic volume, vehicle mix, vehicle speed, and roadway geometry to compute the "equivalent noise level". A computer code has been written which computes equivalent noise levels for each of the time periods used in CNEL. Weighting these noise levels and summing them results in the CNEL for the traffic projections used. 4.0 NOISE EXPOSURE The future (buildout) traffic volume for Newport Coast Drive was obtained from Ms. Nancy Velagra at the Orange County Transportation Services on May 2, 2013. The traffic volume, vehicle speed, and roadway grade used in the CNEL calculations are presented below in Table 1. Table 1 FUTURE TRAFFIC VOLUME, SPEED, AND ROADWAY GRADE ROADWAY Newport Coast Drive TRAFFIC VOLUME 17,000 SPEED GRADE 60 <3% The traffic distribution that was used in the CNEL calculations is presented in Table 2. This arterial traffic distribution estimate was compiled by the Orange County Environmental Management Agency, and is based on traffic counts at 31 intersections throughout the Orange County area. Arterial traffic distribution estimates can be considered typical for arterials in Southern California. Page 3 of 6 Mestre Greve Associates 29 Avalon Vista 6 a Division of Landrum & Brown Project #543401-0100 Table 2 TRAFFIC DISTRIBUTION PER TIME OF DAY IN PERCENT OF ADT VEHICLE TYPE DAY EVENING NIGHT Automobile 75.51 12.57 9.34 Medium Truck 1.56 0,09 0.19 Heavy Truck 0.64 0.02 0.08 Using the assumptions presented above, the future noise levels were computed. The results are listed in Table 3 in terms of distances to the 60, 65, and 70 CNEL contours. These represent the distances from the centerline of each roadway to the contour value shown. Note that the values given in Table 3 do not take into account the effect of intervening topography that may reduce the roadway noise exposure. Table 3 DISTANCE TO NOISE CONTOURS FOR FUTURE TRAFFIC CONDITIONS DISTANCE TO CONTOUR (FEET) -70 CNEL- -65 CNEL- -60 CNEL- Newport Coast Drive 69 149 321 * - Contour distances in this table are based on the centerline of the roadway representing the noise source. The rear yard area is approximately 390 feet from the centerline of Newport Coast Drive. At this distance, rear yard observers at this home would be exposed to unmitigated traffic noise levels of about 58.7 CNEL. 5.0 EXTERIOR NOISE LEVELS Rear yards will be exposed to noise levels of about 58.7 CNEL. This is far less than the County's 65 CNEL noise standard. Therefore noise barriers will not be needed. Any balconies would also be exposed to noise levels of far less than 65 CNEL. Therefore, balcony barriers will not be required. Page 4 of 6 Mestre Greve Associates 29 Avalon Vista 6 a Division of Landrum & Brown Project #543401-0100 6.0 INTERIOR NOISE LEVELS Exterior building surfaces at the home will be exposed to noise levels of far less than 65 CNEL, and therefore will require less than 20 dB exterior to interior noise reduction in order to meet the City's 45 CNEL interior noise standard. With construction practices common in California, residential buildings achieve outdoor to indoor noise reductions of at least 20 dB. Therefore, all rooms are projected to meet the City's 45 CNEL interior noise standard without building upgrades. 7.0 ADEQUATE VENTILATION Since the noise attenuation of a building falls to about 12 dB with windows open, buildings exposed to noise levels greater than 57 CNEL will meet the 45 CNEL interior noise standard only with windows closed. In order to assume that windows can remain closed to achieve this required attenuation, adequate ventilation with windows closed must be provided per the applicable California Building Code. Since the noise exposure is projected to be about 58.7 CNEL adequate ventilation will be required for this home. Page 5 of 6 Mestre Greve Associates 6 s Division of Landrum & Brown APPENDIX CALCULATION SPREADSHEETS DATA USED TO DETERMINE EXTERIOR TRAFFIC NOISE LEVELS 29 Avalon Vista Project #543401-0100 Page 6 of 6 2.4 W y F L V N N M M M N oo o�hd r roe h O O N �D iD h