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
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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
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