REVISED NOISE IMPACT STUDY

Size: px

Start display at page:

Download "REVISED NOISE IMPACT STUDY"

Heather Dickerson
5 years ago
Views:

2 REVISED NOISE IMPACT STUDY Benton Boarding and Daycare 5673 Fourth Line Road Ottawa, Ontario City of Ottawa File No. D Integral DX Engineering Ltd. Page 2 of 24

3 TABLE OF CONTENTS 1.0 INTRODUCTION / BACKGROUND INFORMATION REFERENCES PURPOSE CITY OF OTTAWA ZONING BYLAW REQUIREMENTS SOUND LEVEL CRITERIA Indoor Noise Outdoor Noise PREDICTION OF NOISE ATTENUATION LEVELS Target Noise Attenuation Calculation of Barrier Attenuation Barrier Construction Details CITY OF OTTAWA NOISE BYLAW REQUIREMENTS SOUND LEVEL CRITERIA ALLOWABLE UNIT SOUND POWER LEVEL SUMMARY & CONCLUSIONS...12 APPENDIX A : SITE PLANS...14 APPENDIX B : DETAILED NOISE ATTENUATION CALCULATIONS...17 Integral DX Engineering Ltd. Page 3 of 24

4 LIST OF TABLES Table 1: Worst-Case Noise Attenuation for each Outdoor Area...10 Table B.1: Barrier Shielding Factor Values...19 Table B.2: Source-Receiver-Barrier Geometrical Values...20 Table B.3: Fresnel Number and Barrier Attenuation Results...20 Table B.4: Total Attenuation Values...21 Integral DX Engineering Ltd. Page 4 of 24

5 EXECUTIVE SUMMARY Benton Boarding and Daycare is a proposed dog kennel facility, to be located in North Gower (Ottawa), Ontario. The location and surroundings of the new kennel are such that dog runs will be located less than 215 metres from nearby dwellings. As such, noise control measures are required in order to ensure that nearby residents are not unduly disturbed by noise emanating from the new kennel. This report describes a solution that will satisfy a City of Ottawa Bylaw requirement to mitigate noise levels the installation of barriers around outdoor areas of the pet daycare facility. The methodology and calculations used to determine barrier geometry and specifications are included. This report also specifies a maximum HVAC equipment noise level per the City of Ottawa Noise Bylaw. This report is a revised version of the report dated 26 July Edits have been made following comments received from the City of Ottawa. The results indicate that the noise emissions for the site will comply with City of Ottawa Bylaw requirements with the proposed solution implemented. Integral DX Engineering Ltd. Page 5 of 24

6 1.0 INTRODUCTION / BACKGROUND INFORMATION The development of a new Dog Kennel, to be located on the property identified as 5673 Fourth Line Road in Ottawa, is being proposed. The project, which will include 100 or more dog runs as well as feline boarding areas for 20 or more cats, is currently at Site Plan Approval stage. The property at 5673 Fourth Line Road is currently being used for farming operations, with the proposed Dog Kennel to be located on an unused portion of the property. The current farming operations will continue in conjunction with the proposed Kennel. In accordance with the City of Ottawa Zoning Bylaw, the impact of operating the proposed facility is assessed for noise-sensitive receptors close to the site. Noise barrier specifications are described herein that will ensure that the new facility's emissions are compliant with this Bylaw. The new kennel will also include one exterior HVAC unit. This report specifies source noise levels for the unit that comply City of Ottawa Noise Bylaw requirements. 1.1 REFERENCES This study is based on information presented in the following drawings: Site Plan and Erosion Control Plan, Revision 1 dated 28 March 2013 and prepared by Kollaard Associates Engineers; A hand sketch provided by from Mr. Joe Gibson on 26 June 2013, with file name KS10001.jpg Reference is also made to the following correspondence and documents: 1) City of Ottawa Zoning Bylaw Part 3, Section 84 Kennels. Available at the following url: licenses-and-permits/laws/city-ottawa-zoning-law/zoning-law consolidation-30 2) City of Ottawa Noise Bylaw No Available at the following url: 3) Benton Boarding and Daycare Overview for Site Plan Control (undated) Integral DX Engineering Ltd. Page 6 of 24

7 4) City of Ottawa Memo prepared by Laurel McCreight, dated 12 April ) Response to City of Ottawa Memo, prepared by Joe Gibson (undated) 6) Second City of Ottawa Memo prepared by Laurel McCreight, dated 22 March ) City of Ottawa letter by Jim Hall with comments on the previous version of this Noise Impact Study, dated 23 August ) Noise and Vibration Control, Revised Edition (1988) Edited by Leo L. Beranek, and Published by the Institute of Noise Control Engineering 9) Acoustic Parameters of Dog Barks Carry Emotional Information for Humans, Péter Pongrácz et al., Published in the Journal of Veterinary Behaviour, Volume 4, Issue 2, March-April Available for download at the following url: In this report: Unless otherwise indicated, noise levels are reported in terms of a sound pressure levels ( SPL ) in decibels, referenced to 2x10-5 pascals. SWL is used to indicate a sound power level in decibels with reference level watts. 1.2 PURPOSE The purpose of this report is to demonstrate that this project can be developed in a manner that conforms to Section 84 of the City of Ottawa Zoning Bylaw, as well as the City of Ottawa Noise Bylaw. Integral DX Engineering Ltd. Page 7 of 24

8 2.0 CITY OF OTTAWA ZONING BYLAW REQUIREMENTS 2.1 SOUND LEVEL CRITERIA The new Kennel will be located approximately 160 m from the nearest residential building located on a different property. Per Section 84 of the City of Ottawa Zoning Bylaw, the minimum separation distance for a Kennel with more than four dog runs is 215 m, or 50 m if it can be demonstrated to the satisfaction of the City that the facility will include features to attenuate all Kennel-related noise so as not to become a nuisance to surrounding dwellings Indoor Noise Noise generated from within the kennel building will be significantly attenuated by the building envelope. Air conditioning will be provided in all areas with continuous 100% fresh air circulation, therefore allowing windows to remain closed. The office is located on the South-West end of the building closest to nearby residences this arrangement provides a buffer between the indoor portion of the kennel and the outdoors, and will mitigate the potential for indoor kennel noise to be audible for brief moments when the door to the building is opened. It is thus concluded that noise generated from within the kennel building will be insignificant at all nearby residential buildings Outdoor Noise The kennel will feature four outdoor areas, including dog runs and play areas. These will be mitigated for sound with the installation of noise barriers. The proposed barriers will be designed so that the total attenuation (due to the actual available separation distance, plus noise barrier) is equal to or greater than the attenuation that what would be achieved with a 215 m separation distance alone. This will ensure that noise levels at residential buildings are no greater than what would be achieved with a 215 metre separation distance, thereby complying with Section 84 of the Zoning Bylaw. Outdoor noise levels will also be managed by limiting outdoor play time to the daytime only (07:00 to 19:00). Integral DX Engineering Ltd. Page 8 of 24

9 2.2 PREDICTION OF NOISE ATTENUATION LEVELS The revised edition of Noise and Vibration Control (Leo L. Beranek) has been used to determine noise attenuation levels due to distance and barrier shielding of the outdoor areas of the proposed kennel Target Noise Attenuation As discussed above, the target attenuation for the dog kennel's outdoor runs was set as the attenuation achieved at a 215 m distance between source and receiver. Considering dog barking as a point source with hemispherical spreading, this corresponds to 54.6 db of noise attenuation (see Appendix B). Greater levels of noise attenuation will result in noise levels quieter than would be achieved by the 215 m separation distance required in the City of Ottawa Zoning Bylaw Calculation of Barrier Attenuation The attenuation due to barrier shielding is frequency-dependant, with lower frequencies being attenuated less than higher frequencies, all else being equal. Per L.L. Beranek, a minimum attenuation of 5 db applies at all frequencies when line-of-sight between source and receiver is broken by the barrier. Barrier heights have thus been selected to ensure line-of-sight is obstructed for all receivers, with a small margin. The table below summarizes the resulting minimum recommended barrier heights, as well as the actual attenuation that will be achieved for the worst-case receptor for each enclosure. The attenuation levels shown consider the resulting barrier attenuation at 125 Hz. In reality, the majority of the sound power from dogs barking is at higher frequencies. Based on a research paper by Péter Pongrácz et al., a low-pitch dog bark has an average sound frequency in the 500 to 700 Hz range, based on 189 measurement samples of 15 Mudi dogs. These frequencies have higher attenuation values, as shown in the calculations included as Appendix B. Each barrier is identified on the Site Plans in Appendix A. Integral DX Engineering Ltd. Page 9 of 24

10 Table 1: Worst-Case Noise Attenuation for each Outdoor Area Barrier Minimum Barrier Height Worst-Case Noise Attenuation Target Noise Attenuation A 2.0 m 58.3 db 54.6 db B 2.0 m 59.0 db 54.6 db C 2.0 m 59.4 db 54.6 db D 2.0 m 60.3 db 54.6 db Note that, for each of the identified barriers, the worst-case attenuation level shown above will increase with any increase in the barrier height Barrier Construction Details Each noise barrier must be constructed of a solid and continuous material, with no gaps at the base of the barrier, at barrier corners, between individual panels/sections, or elsewhere. The barrier material should provide a transmission loss of at least 20 db, so that the noise travelling through the material is negligible compared to the noise diffraction over the top of the barrier. For instance, steel panels with a minimum thickness of 0.95 mm (20 gauge or thicker) will meet this requirement. As shown on the Site Plan, barriers A and B must return to the building at the North-East edge. This will avoid the potential for noise generated in these areas to be reflected off of the C or D barriers, and travel back in the direction of residential buildings. Any outdoor access to these areas should be installed on the North-East side. Barriers C and D do not have this condition, and as such have no requirement for a noise barrier on the North-East segment. Integral DX Engineering Ltd. Page 10 of 24

11 3.0 CITY OF OTTAWA NOISE BYLAW REQUIREMENTS 3.1 SOUND LEVEL CRITERIA Per Items 4 and 5 of the City of Ottawa Noise Bylaw, HVAC and exhaust equipment must not exceed 50 dba measured at the point of reception. 3.2 ALLOWABLE UNIT SOUND POWER LEVEL The proposed HVAC unit will be located near the back of the new kennel. While the exact location of the unit is not known, this assessment presumes a worst-case scenario. As shown on the Site Plan (Appendix A), the unit is presumed to be at roughly the mid-point of the rear section of the building, located on the rooftop. Line-of-sight is presumed between source and receiver, meaning that no barrier shielding has been accounted for. In this location, there is approximately 185 m of horizontal separation to the property line of the nearest residence across Fourth Line Road. Per L.L. Beranek, this corresponds to 53 db of noise attenuation due to distance (see calculation example in Appendix B). Therefore, in order to meet the City's 50 dba requirement, the sound power level of the unit must not exceed 103 dba SWL. Integral DX Engineering Ltd. Page 11 of 24

13 Attachments: Appendix A: Site Plans Appendix B: Detailed Noise Attenuation Calculations Integral DX Engineering Ltd. Page 13 of 24

14 APPENDIX A: SITE PLANS (attachment to Integral DX Engineering Ltd. report dated 11 September 2013) Integral DX Engineering Ltd. Page 14 of 24

15 Integral DX Engineering Ltd. Page 15 of 24

16 Integral DX Engineering Ltd. Page 16 of 24

17 APPENDIX B: DETAILED NOISE ATTENUATION CALCULATIONS (attachment to Integral DX Engineering Ltd. report dated 11 September 2013) All calculations have been completed in accordance with the revised edition of Noise and Vibration Control (Leo L. Beranek). The procedure, which considered Distance Attenuation and Barrier Attenuation, is summarized below. Attenuation due to atmospheric absorption was not considered. Distance Attenuation A barking dog was considered as a point source with hemispherical radiation above the ground. This condition is covered on page 166, equation 7.3 (L.L. Beranek): Where L P =L W 20log 10 (r) 8 (1) L P is the sound pressure level at the point of reception in decibels; L W Is the sound power level of the source, in decibels; and r is the distance between the source and the point of reception, in metres. The total attenuation due to distance is thus given (in decibels) by: Distance Attenuation=20log 10 (r)+8 (2) Barrier Attenuation The proposed dog kennel meets the following conditions: 1. The sound is incident from a point source; 2. The distance between the point source and barrier edge is small compared to the distance between the barrier edge and receiver; and 3. The receiver is located in the shadow zone, meaning that the barrier fully obstructs line-of-sight between the source and receiver. Integral DX Engineering Ltd. Page 17 of 24

18 Under the above conditions, the attenuation due to barrier shielding is given as follows (L.L. Beranek, pages ): Barrier Attenuation=20 log 10( 2π N tanh 2π N ) +5dB (3) Where N is the Fresnel number (dimensionless). N =± 2 λ (A+B d) (4) In Equation (4), λ is the wavelength of sound in metres; A+B is the shortest path length of wave travel over the wall between source and receiver in metres; and d Is the separation distance between the source and receiver. The barrier attenuation can be found at a given frequency of sound (in Hertz) by determining the corresponding wavelength (in metres), and knowing the speed of sound in air (in metres per second): λ= c f (5) The speed of sound in air at 20 C is approximately m/s (L.L. Beranek). Total Attenuation The total attenuation, in decibels, is the sum of the Distance Attenuation and the Barrier Attenuation. As noted above, attenuation due to sound absorption in the atmosphere was not considered. Analysis The table below shows the results of noise attenuation calculations. The attenuation due to a distance of 215 m is first determined, which sets the criteria for all other predictions. Predictions were then made to one or several potential Integral DX Engineering Ltd. Page 18 of 24

19 worst-case source-receiver scenarios. In most cases this corresponds to the scenario providing the least barrier shielding any decline in distance attenuation for dogs located closer to the barriers is minor compared to the associated increase in barrier attenuation. The calculations were completed for barriers measuring 2 metres in height. This height obstructs line-of-sight of all source-receiver paths, and as the calculations show, provide a total attenuation above the target attenuation in all scenarios. The lines referenced below are identified in the Site Plans following. Table Error: Reference source not found.1: Source-Receiver-Barrier Geometrical Values Scenario Heights (m) Barrier Horizontal Fresnel Line of Angle Distances (m) Distances (m) sight? (deg) Location Barrier Source Receive Barrier Barrier to Source to Source to Src-Rec Receive Barrier line, ccw d A+B yes/no Line A1 A No Line A2 A No Line A2 A No Line B1 B No Line B2 B No Line B3 B No Line C1 C No Line C2 C No Line D1 D No Integral DX Engineering Ltd. Page 19 of 24

20 Table Error: Reference source not found.2: Fresnel Number and Barrier Attenuation Results Scenario Fresnel Number (dimensionless) at Frequency (Hz) Attenuation (db) at Frequency (Hz) Location Barrier Line A1 A Line A2 A Line A2 A Line B1 B Line B2 B Line B3 B Line C1 C Line C2 C Line D1 D Table Error: Reference source not found.3: Total Attenuation Values Distance (m) Attenuation (db) Total Attenuation (db) Description Due to Barrier Distance Effect City of Ottawa Bylaw Exclusion Distance Line A Line A Line A Line B Line B Line B Line C Line C Line D Integral DX Engineering Ltd. Page 20 of 24

21 Integral DX Engineering Ltd. Page 21 of 24

22 Integral DX Engineering Ltd. Page 22 of 24

23 Integral DX Engineering Ltd. Page 23 of 24

24 Integral DX Engineering Ltd. Page 24 of 24

NOISE IMPACT STUDY. Benton Boarding and Daycare 5673 Fourth Line Road Ottawa, Ontario City of Ottawa File No. D

NOISE IMPACT STUDY. Benton Boarding and Daycare 5673 Fourth Line Road Ottawa, Ontario City of Ottawa File No. D NOISE IMPACT STUDY Benton Boarding and Daycare 5673 Fourth Line Road Ottawa, Ontario City of Ottawa File No. D07-12-13-0024 Page 2 of 23 TABLE OF CONTENTS 1.0 INTRODUCTION / BACKGROUND INFORMATION...6