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Item 7BCity of Southlake &WON 's Department of Planning MW 1400 Main Street, Suite 310, Soutlilake, TX 76092 MEMORANDUM February 13, 2005 TO FROM SUBJECT The Honorable Mayor and City Council Ken Baker, AICP, Planning Director Variance to Chapter 11, Article III of the Southlake City Code (Noise Nuisances) for the Shops at Southlake (Central Market). REQUESTED ACTION: Consider the requested variance to the Noise Code. BACKGROUND: The Southlake City Code, Chapter 11, Article III (Noise Nuisances) regulates noise levels in the city. The standards established are as follows: The image below shows typical examples for different decibel levels of sound: Sound Pressure Level, dB 120 Property receiving sound Daytime Nighttime Sundays 2 Residential 60 dBA 55 dBA 55 dBA 80 Commercial 70 dBA 65 dBA 65 dBA The image below shows typical examples for different decibel levels of sound: Sound Pressure Level, dB Stmid Pressure. Pa 1 D 120 Pneumatic Chipper (a15 it) 110 TesilIG I-mm 2 100 Newspaper Pr$ss (At pera9nt's earl 0.6 0.2 80 01asel Thank 40 mph {al 5o III Vacuum Gleaner 0'05 80 Passowger Car 60 mph {at 50 lI I 70 Coiversatim i at 3 ftl 60 5.51 50 Qu 401 Roan 40 OAR 30 0.001 20 0.0005 10 0.0002 0 Stmid Pressure. Pa 1 D Rock-n -Roll Band 5 2 Puwa,t Lawn Mower 1 (At pera9nt's earl 0.6 0.2 Milling Maakine (at4 h Garbage Disposal (at 3 It) 0A Vacuum Gleaner 0'05 U2 Air Coiditioiing (1Nindew U i it at 25 tt) 5.51 0.005 OAR 0.001 0.0005 0.0002 00001 0.00005 0.00002 1 Shops at Southlake, located at the southeast corner of F.M. 1709 and S. Carroll Avenue, may require a variance from the above standard. At present, a 14' high wall has been approved along the southern property line to buffer the adjoining residences from noise nuisances expected to be generated by the proposed adjacent commercial operations. However, it has now been determined that a 16' high wall is necessary to meet the City's noise ordinance. Attached with this memo is an exhibit depicting the area affected by this variance request. Also attached are letters from the developer's acoustical consultant with information pertaining to noise analysis at the southern edge of the subject property. ATTACHMENTS: Site Plan Exhibit Acoustical consultant's letter Acoustical consultant's noise level analysis 2 z V qi z Y� CT lei 0 Eo At 4 7 � { ; � � � ��� r - .. _.. - — , " � '� , ��� to 1-- 1 7� N4 'j 79AV 0, IL CIN 1 ell w", 6i I D i �t n w L 7 N F 2 p l7 � IM 0 I W Ul O +� N � W Ups � � A I kda 2 as 0 r �y r F � C b c P7 r O S � r [D V I � V z J J U in r iD7 = LLI 7 i C7 D� `Z J � J EY a o EL C7 a a >— ' tE) ° LU N C� 11 yj§4 O V J 1 ICS MEMORANDUM ngineered 'Vibration Acoustic & Noise Solutions 1705 West Koenig Lane Austin, Texas 75756 -1206 Tel 512/371 -0800 Fax 512/371 -0825 www.JEAcuustics.rom To: Jennifer Tindel, Cencor "om: Chad Himmel Cory: Brian Thomas, Selser Schaefer DATE: February 13, 2006 PAGES: 5 RE: Shops at Southlake - Environmental Noise Control H -E -B Central Market Rooftop Refrigeration Equipment and East Truck Traffic Noise Barriers JEA #: 2531 JEA has reviewed the environmental noise impacts of tractor- trailer traffic anticipated along the delivery driveway located near the south edge of the Shops of Southlake property and east of the center line of the H -E -B Central Market building in Southlake, Texas. We have also reviewed refrigeration equipment changes and relocation for the H -E -B Central Market, with respect to noise received on residential properties and compliance with the Southlake Noise Ordinance. JEA estimated delivery truck noise levels received on residential properties located south of the development site, and has developed recommendations for barrier heights required to achieve Southlake Noise Ordinance limits. HEB refrigeration equipment has changed from grade- mounted equipment to roof - mounted Hussmann Protocol/LAVA systems, including four outdoor roof mounted Protocol refrigeration units with scroll compressors, and nine LAVA condenser units with condenser fans (see attached information). JEA estimated refrigeration equipment noise levels received on residential properties located south of the development site for comparison with Southlake Noise Ordinance limits. Southlake Noise Ordinance The Southlake Noise Ordinance' defines objective noise levels allowed to be received on a residential zoned property: 1 City of Southlake, Code of Ordinances, Ordinance No. 778 5 CO 1 V Shops of Southlal�e J i February 13, 2006 E Vibration Acoustic & Noise Solutions Page 2 Limits for Noise Received on Residential Zoned Property Daytime Nighttime Sundays 60 dBA 55 dBA 55 dBA Noise from non -HEB Shops of Southlake tenant tractor - trailers on the southeast portion of the driveway will be scheduled to occur during daytime hours (7 am to 10 pm) and will not occur on Sundays. Therefore, the controlling objective limit in the ordinance would be 60 dBA at the property line for tractor - trailer noise received on south neighboring properties. Noise from HEB refrigeration equipment may be occurring during night hours and during the daytime on Sundays. Therefore, the controlling objective limit in the ordinance would be 55 dBA at the property line for equipment noise received on south neighboring properties. Estimated tractor noise levels received on south neighboring residential properties are based on JEA's measurements of noise from single passing tractor - trailers with high diesel exhaust stack terminals (exhaust at about 12' above pavement). Estimated refrigeration equipment noise levels are based on the HEB roof plan, parapet elevations, equipment locations and heights, and manufacturer's noise data provided to us. Changes in terrain, driveway pavement elevation, potential locations of receiver points at about 5 feet above grade, and acoustical reflections from building faces and other hard surfaces were included in noise estimates. Barrier Height Requirements for Tractor - Trailer Noise To achieve Ordinance limits, the west portion of the property line barrier height should be such that top of barrier is 14 ft above driveway pavement elevation, up to a point that is about in line with the center line of the HEB building. East of the center line of the HEB building, the top of barrier should be 13 ft above driveway pavement elevation, up to a point that is 250 ft from the east end of the property. At that point, the elevation of top of barrier above sea level should remain constant at 647' until it reaches the detention pond, where it should be increased gradually from 647' to 652'. Because the terrain also increases in height towards the east, the barrier height above grade along the south property line is expected to gradually step down from about 15 ft to about 7 ft above grade. The attached sketch shows required top of barrier elevation above sea level and approximate heights above grade (in parentheses). To accommodate fluctuations in terrain and drive elevations, relatively small portions of the barrier may be slightly lower, up to 1 ft lower, than the elevations I OUS 1 I VS Feb Shops ar 13, 2006 i February 13, E Vibration Acoustic & Noise Solutions Page 3 recommended in this report and in the attached sketch. As the driveway and truck traffic turns farther north of the property line, no noise barrier is needed for properties to the east to achieve Southlake Noise Ordinance requirements. Therefore, the barrier may be stopped at the east property line, as shown in the sketch. Design of the barrier should be the same as we have recommended and coordinated for previous designs of the property line barrier (ref. JEA report September 12, 2005). Where a gap is required at the bottom of the barrier for site drainage, there should be a curb or berm configured such that there is not direct line of sight view of truck traffic below the barrier from the south side of the barrier. Predicted Noise Levels for Refrigeration Equipment Outdoor HEB rooftop refrigeration condenser and compressor equipment noise with the current design is estimated to be between 47 dBA to 52 dBA, received at most areas 5 ft above grade on neighboring properties. Some areas on neighboring properties will receive less refrigeration equipment noise, depending on sight lines determined by location with respect to the noise barrier planned at the property line and the roof parapet, which will act as a noise barrier. Therefore, rooftop equipment noise with the current design is expected to meet the Southlake Noise Ordinance without need for additional noise mitigation measures. The south property line noise barrier that has been planned and coordinated to reduce tractor - trailer noise does not affect (and does not reduce) refrigeration condenser noise received at many areas of the neighboring residential properties. However, it will obstruct view of the four compressors and will reduce equipment noise received in most areas south of the property line. Submitted by: C )j �_I� Chad Himmel Associate JEAcoustics 7 OUS 1 I VS Feb Shops ar 13, 2006 i February 13, E Vibration Acoustic & Noise Solutions Page 4 Outdoor Protocol Refrigeration Units Sound Power per ARI 370 & ISO Standard 3741 = 88.5 dBA with all compressors and exhaust fans operating. Each of the four (4) Outdoor Units (RA, RD, RE, RG) has the same rating. Each has the same number of compressors. Estimated spectral noise values: Outdoor LAVA Protocol Condenser Units Models are all "Low- Noise" models, 1.0 HP, 850 RPM: "RA " 1 X 4 Fan, "RB " 1 X 5 Fan, "RC " 1 X 5 Fan, "RD " 1 X 5 Fan, "RE " 1 X 5 Fan, "RF" 1 X 5 Fan, "RG " 1 X 4 Fan, "RH " 1 X 5 Fan, and "RI" 1 X 4 Fan. Estimated Sound Power (dB) per Octave Band Center Frequency (Hz) dBA 63 125 250 500 1000 2000 4000 8000 88.5 90 90 88 88 80 80 80 75 Outdoor LAVA Protocol Condenser Units Models are all "Low- Noise" models, 1.0 HP, 850 RPM: "RA " 1 X 4 Fan, "RB " 1 X 5 Fan, "RC " 1 X 5 Fan, "RD " 1 X 5 Fan, "RE " 1 X 5 Fan, "RF" 1 X 5 Fan, "RG " 1 X 4 Fan, "RH " 1 X 5 Fan, and "RI" 1 X 4 Fan. Estimated spectral noise values: SPEED OVERALL at 5 feet at 10 feet at 20 feet at 30 feet FAN CONFIGURATION RPM SWL dB(A) SPL dB(A) SPL dB(A) SPL dB(A) SPL dB(A) 1 x 4 850 86.4 74.9 68.9 62.9 59.4 1 x 5 850 87.4 75.9 69.9 63.9 60.4 Estimated spectral noise values: Estimated Sound Pressure at 5' (dB) per Octave Band Center Frequent (Hz) dBA 63 125 250 500 1000 2000 4000 8000 75.9 90 85 78 74 68 63 63 60 ve in O If) I c 4 z _ -l -- _ - - - -- .—.— irl J �i tG 04 o E- A' P-1 2