HomeMy WebLinkAboutCT 02-17; Shelley Property; Tentative Map (CT) (3)PA<!Fic NOISE CON.fttoL
219 Woodland Drive • Vista, CA 92083 • (760) 758-1198. Fax (760) 758-4761
December 1, 2004
Mr. Chuck Duvivier
Fair Oaks Valley, LLC
P.O. Box 230638
Encinitas, CA 92023
PROJECT: Shelley Property--Carlsbad, CA
RE: Environmental Noise Assessment
Dear Mr. Shelley:
Pacific Noise Control has completed this environmental noise assessment for the Shelley Property
project located in the City of Carlsbad. In summary, the future noise level at the lots adjacent to
Camino Junipero would exceed the City's 60 dB CNEL exterior noise criteria. Noise barriers
ranging from four to ten-feet in height would be required to mitigate the noise impact.
An interior noise study will be required prior to issuance of building permits if two story or
higher homes are located on Lots 1, 8-22 and 49 to ensure that the interior CNEL would not
exceed 45 dB. The homes on these lots would most likely require air-conditioning and/or
mechanical ventilation system to meet the City's interior noise standard. Sound-rated windows
may also be required for some of the residences on these lots.
1.0 BACKGROUND
Project Setting
The Shelley Property project site is located approximately 3,000 feet east of the intersection of La
Costa A venue and Camino de los Coches in the City of Carlsbad (Figure 1). The project would
develop the site with 49 single family lots. In the future, Camino Junipero (formerly named
Melrose Drive) would bisect the site. This noise analysis evaluates the exterior noise level
resulting from traffic along Camino Junipero. The analysis is based on the tentative map (O'Day
Consultants, November 4, 2004).
RECEIVED
DEC 0 3 2004
I'"
LADWIG DESIGN GR oD}
lrll/v
Mr. Chuck Duvivier
Shelley Property--Environmental Noise Assessment
City Noise Criteria
December 1, 2004
Page2
The City of Carlsbad requires exterior noise levels at new single family residences not exceed a
Community Noise Equivalent Level (CNEL) of 60 dB at 20-feet from the rear/side of the
structure, unless the rear/side yard is less than 20-feet deep. Where the useable rear/side yard is
less than 20-feet deep, the location may be taken at the back of the useable rear/side yard, as may
be approved by the Planning Director. Interior noise levels are not to exceed a CNEL of 45 dB.
All sound levels discussed in this report are A-weighted.
Methodology
The noise analysis methodology is based on the City's noise assessment methodology documented
in the City's Noise Guidelines Manual (City of Carlsbad, 1995). The future noise level along
Juniper Road was determined using Caltrans' SOUND32 Highway Traffic Noise Prediction Model
(Caltrans, 1983) with California noise emission factors (Caltrans, 1987). The noise model is
based on the Federal Highway Administration's traffic noise prediction model (FHWA, 1978).
The future year 2020 traffic volume forecast for the road is 1 ,000 ADT (City of Carlsbad 2002a).
The traffic projection assumes that the road would terminate within the City of Carlsbad.
However, the road right-of-way is being reserved as a connecting circulation element road. This
road has a traffic capacity volume of approximately 40,000 ADT. Therefore, the input for the
noise model included the future road design capacity traffic volume of 40,000 ADT (City of
Carlsbad, 2002b) with vehicle speeds of 45 mph.
2.0 ~AJL~SIS
2.1 Exterior Noise
Camino Junipero would be the primary noise source in the future. Lots 1 and 8-21 adjacent to
Camino Junipero would be exposed to a future CNEL greater than 60 dB. The first floor CNEL
would range up to approximately 71 dB at these lots. The noise level would exceed the City's
noise guideline by up to 11 dB, and would result in a significant noise impact unless mitigation
measures are incorporated into the project. The backyards of the remaining single family lots
would be exposed to a future CNEL of 60 dB or less due to the proposed setback distance, and/or
the topographic shielding associated with the grade elevation difference between the lots and
Camino Junipero. The future first floor noise levels at the backyards of several representative lots
are depicted in Figure 2.
As noted earlier, the future traffic volume is anticipated to be approximately 1,000 ADT adjacent
to the site if Camino Junipero terminates within the City of Carlsbad. This traffic volume would
Mr. Chuck Duvivier
Shelley Property--Environmental Noise Assessment
December I, 2004
Page3
result in a CNEL of approximately 55 dB CNEL at the closest lots to the road. This noise level
would comply with the City's noise criteria.
2.2 Interior Noise
The City requires that interior noise levels not exceed a CNEL 45 dB. Typically, with the
windows open, and using standard California construction materials and methods, the building
shells provide approximately 15 dB of noise reduction. Therefore, residences exposed to an
exterior CNEL greater than 60 dB could result in an interior CNEL greater than 45 dB. The
exterior noise level at Lots 1, 8-22 and 49 would exceed 60 dB CNEL at the first and/or second
floor levels.
2.3 Rock Crushing and Blasting
A portable rock crusher would be used onsite during construction. The crushing operation would
begin with a front loader picking up material and dumping the material into a primary crusher. The
material would be then crushed, screened and stacked in product piles. Electric power would be
provided by a diesel engine generator.
The closest homes would be located near the southeastern portion of the site. These homes are
currently being constructed. The homes have/would have masonry walls along the backyards that
face the project site. These off-site lots adjacent to the project site range in elevation from
approximately 466 to 484 feet.
Based on noise measurements that have been conducted for portable rock crushing operations, the
rock crushing activity would generate a one-hour average noise level of approximately 86 dB at 50
feet from the primary crusher. Assuming the rock crusher is operated during the daytime hours for
a period often-hours each day, the CNEL would be approximately 82 dB at 50 feet. To reduce the
CNEL to 60 dB at the backyards of the off-site residences, the rock crushing operations could be
located near the southern property boundary at the project's Lots 40, 48 or 49. This conservatively
assumes an attenuation of five dB that would result from the backyard walls at the off-site
residences. Alternatively, the rock crushing operations could be located farther away at Lot 38.
Blasting may be required during construction if rock encountered during grading cannot be ripped
by bulldozers. Construction blasting generates a maximum noise level of approximately 94 dB at
a distance of 50 feet (BBN 1989). The blast is generally perceived as a dull thud, rather than as a
loud explosion. The closest homes to the on-site limits of grading would be located more than 60
feet away. Assuming blasting activities are conducted adjacent to the closest home, the maximum
noise level would be approximately 92 dB. This noise level would be noticeable, but, would not
Mr. Chuck Duvil'ier
Shelley Property--Enl'ironmental Noise Assessment
December 1, 2004
Page4
result in a significant noise impact because of the infrequent nature of blasting.
Vibration levels associated with blasting would vary. Ground-borne vibration is influenced by the
soil conditions and the receiving building. Vibration source levels associated with construction
blasting are typically a peak particle velocity of approximately 0.80 inches per second at a distance
of 25 feet (FTA 1995). At a distance of 60 feet peak particle velocity would be approximately 0.2
inches per second. The U.S. Bureau of Mines has set a peak particle velocity "safe blasting limit"
of 2.0 inches per second from single events such as dynamite blasts. Below this level there is
virtually no risk ofbuilding damage (Caltrans 2002). This vibration level would be perceptible to
people, but because of the infrequent nature of blasting would result in a less than significant
vibration impact.
It is anticipated that blasting operations, if necessary, would be in general conformance with the
blasting specifications prepared by the U.S. Bureau of Mines. The blasting contractor would be
required to limit the blasting intensities so as to prevent damage to all existing structures, and in no
case would intensities exceed the safety standard of particle velocity recommended by the U.S.
Bureau of Mines.
3.0 MITIGATION
3.1 Exterior Noise
To mitigate the exterior noise impact at the single family residences would require noise barriers
ranging from four to ten feet in height along Lots 1 and 8-21. The noise barrier heights and
locations are depicted in Figure 3. The heights of the walls are relative to the pad elevations at
Lots 1, 12-21 and relative to the top of slope elevations at Lots 8-11.
The noise barriers may be constructed as a wall, berm or combination of both. The noise barriers
must have a surface density of at least 3. 5 pounds per square foot, and have no openings or cracks.
The wall may be constructed of 5/8-inch Plexiglas, any masonry material or a combination of
these materials.
As previously noted, to reduce the CNEL to 60 dB at the backyards of the off-site residences, the
rock crushing operations could be located near the southern property boundary at the project's Lots
40, 48 or 49. Alternatively, the rock crushing operations could be located farther away at Lot 38.
Also, it should be noted that mitigation would not be required if Camino Junipero terminates
within the City of Carlsbad.
Mr. Chuck Duvivier
Shelley Property--Environmental Noise Assessment
3.2 Interior Noise
December 1, 2004
PageS
If two story or higher homes are located on Lots 1, 8-22 and 49 an interior noise analysis will be
required to comply with the City's interior noise criteria. This assumes implementation of the
noise barriers identified above in Section 3 .1. The interior acoustical analysis will be required for
the residences on these lots prior to issuance of building permits to ensure that the interior CNEL
would not exceed 45 dB. To mitigate the interior noise impact, the residences on these lots would
most likely require air-conditioning and/or mechanical ventilation and possibly sound-rated
windows.
The mitigation measures are based on the tentative map. If changes are made to the proposed
building pad elevations or lot setbacks as shown in the tentative map, a noise study will be
required to determine whether the proposed barrier heights and locations will mitigate the noise
level.
This concludes our noise assessment. If you have any questions, please call me.
Sincerely,
Mike Komula
Acoustician
Mr. Chuck Duvivier
Shelley Property--Environmental Noise Assessment
December 1, 2004
Page6
REFERENCES
Bolt, Beranek and Newman, Inc., 1989. Noise Controlfor Buildings and Manufacturing Plants.
California Department of Transportation (Cal trans), June 1983. User's Instructions for SOUND 32
(FHWA/CA-83106).
California Department of Transportation (Caltrans), 1987. California Vehicle Noise Emission
Levels, (FHWA/CAffL-87/03).
California Department of Transportation (Cal trans), February 20, 2002. Transportation Related
Earthborne Vibrations TAV-02-0J-R9601.
Carlsbad, City of, September 1995. City of Carlsbad Noise Guidelines Manual.
Carlsbad, City of, June, 2002a. Personal Communication with Mr. Jim Murray Traffic
Engineering Department.
Carlsbad, City of, June, 2002b. Personal Communication with Mr. Clyde Wickham.
Federal Highway Administration (FHWA), 1978. FHWA Highway Traffic Noise Prediction
Model (FHWA-RD-77-108).
Federal Transit Administration (FTA), April 1995. Transit Noise and Vibration Impact
Assessment.
U.S. Bureau of Mines, Report RI 8507 Structure Response and Damage Produced by Ground
Vibrations from Surface Blasting.
-------------------------------
ATTACHMENT 1
DEFINITIONS
Term Definition
Ambient Noise Level The composite of noise from all sources near and far. The normal
or existing level of environmental noise at a given location.
A-Weighted Sound Level, dBA The sound pressure level in decibels as measured on a sound level
meter using the A-weighted filter network. The A-weighting filter
de-emphasizes the very low and very high frequency components of
the sound in a manner similar to the frequency response of the human
ear and correlates well with subjective reactions to noise.
Community Noise Equivalent Level, CNEL is the A-weighted equivalent continuous sound exposure level
for a 24-hour period with a ten dB adjustment added to sound levels
occurring during nighttime hours ( 10 pm to 7 am) and a five dB
adjustment added to the sound levels occurring during the evening
hours (7 pm to 10 pm).
Decibel, dB A unit for measuring sound pressure level and is equal to 10 times
the logarithm to the base 10 of the ratio of the measured sound
pressure squared to a reference pressure, which is 20 micropascals.
Time-Average Sound Level The sound level corresponding to a steady state sound level
containing the same total energy as a time varying signal over a
given sample period. It is designed to average all of the loud and
quiet sound levels occurring over a time period.
ATTACHMENT 2
TRAFFIC NOISE MODELING INPUT/OUTPUT
0
No Scale
Pacific Noise Control Regional Location FIGURE 1
0
0 FEET 250
Base Map Source: O'Day Consultants, November 4, 2004
Pacific Noise Control Future CNEL Noise Levels FIGURE 2
0
1" = 150'
Base Map Source: O'Day Consultants, November 4, 2004
• • • • I Noise Barrier
I /~
~~ "" '"" ~ ~~
Pacific Noise Control Noise Barrier Heights and Locations FIGURE 3
Term
Ambient Noise Level
ATTACHMENT 1
DEFINITIONS
Definition
The composite of noise from all sources near and far. The normal
or existing level of environmental noise at a given location.
A-Weighted Sound Level, dBA The sound pressure level in decibels as measured on a sound level
meter using the A-weighted filter network. The A-weighting filter
de-emphasizes the very low and very high frequency components of
the sound in a manner similar to the frequency response of the human
ear and correlates well with subjective reactions to noise.
Community Noise Equivalent Level, CNEL is the A-weighted equivalent continuous sound exposure level
for a 24-hour period with a ten dB adjustment added to sound levels
occurring during nighttime hours ( 10 pm to 7 am) and a five dB
adjustment added to the sound levels occurring during the evening
hours (7 pm to 10 pm).
Decibel, dB
Time-Average Sound Level
A unit for measuring sound pressure level and is equal to 10 times
the logarithm to the base 10 of the ratio of the measured sound
pressure squared to a reference pressure, which is 20 micropascals.
The sound level corresponding to a steady state sound level
containing the same total energy as a time varying signal over a
given sample period. It is designed to average all of the loud and
quiet sound levels occurring over a time period.
ATTACHMENT 2
TRAFFIC NOISE MODELING INPUT/OUTPUT
e
Shelley--Mitigated (SHELLY.MIT)
T-Junipero Road, 1
1957 t 45 t 37 1 45 t 6 1 45
T-Junipero Road, 2
1957 1 45 1 37 1 45 1 6 1 45
L-Northbound, 1
N,166.,269,421,NB1
N,250.,460,418,NB2
N,390.,710,418,NB3
N,449.,810,420,NB4
N,510.,920,428,NB5
N,639.,1088,439,NB6
N,739.,1200,445,NB7
N,879.,1314,451,NB8
N,1008.,1406,456,NB9
N,1192.,1508,457,NB10
N,1291.,1530,458,NB11
N,1419.,1570,456,NB12
N,1570.,1608,455,NB13
N,1960.,1679,453,NB14
N,2571.,1779,436,NB15
L-SOUTHBOUND, 2
N,117.,272,421,SB1
N,201.,477,418,SB2
N,341.,720,418,SB3
N,405.,838,420,SB4
N,470.,946,428,SB5
N,600.,1120,439,SB6
N,699.,1230,445,SB7
N,832.,1349,451,SB8
N,979.,1449,456,SB9
N,1159.,1542,457,SB10
N,1270.,1574,458,SB11
N,1400.,1620,456,SB12
N,1562.,1658,455,SB13
N,1960.,1730,453,SB14
N,2559.,1827,436,SB15
B-BARRIER (Lots 8-11), 1 , 2 , 0 ,0
310.,925,413,419,B1
348.,908,413,419,B2
390.,885,420,426,B3
420.,918,424,430,B4
455.,970,427,432,B5
578.,1139,439,443,B6
680.,1249,445,449,B7
733.,1305,447,451,B8
B-BARRIER (LOTS 12-15) I 2 I 2 I 0 ,0
600.,800,428,436,W1
540.,818,428,438,W2
590.,905,428,438,W3
593.,905,430,440,W3b
660.,1005,430,440,W4
662.,1005,435,445,W5
720.,1075,435,445,W6
722.,1075,441,451,W7
785.,1145,441,451,W8
787.,1147,448,458,W8B
B-Barrier Lot 16, 3 , 2 , 0 ,0
787.,1147,448,458,W8B
858.112101448 1458 1W9
S95.11155144814561W10
B-BARRIER (LOTS 17-19)1 4 I 2 I 0 10
972.11200 1459 1467 1W11
930.11255 14591467 1W12
960.11270 1459 1467 1W14
1040.11272 14591467 1W15
1065.11272 14661474 1W16
1125.11295 1466 1474 1W17
1145.112901474 1482 1W18
1178.113051474 1481 1BB15a
B-BARRIER (LOTS 19-20)1 5 I 2 I 0 10
1178.11305147414811bb15b
1195.11315147414811bb16
1262.11318148014861bb17
B-Topol 6 I 1 I 0 10
1262.113181480 1480 1BB17
1318.11328 1490 1490 1BB18
1365.113281500 1500 1BB19
1455.11330 1510 1510 1BB20
1550.11332 1520 1520 1BB21
1703.113421520 1520 1BB22
1762.11343 1518 1518 1BB23
1871.11348 1514 1514 1BB24
1913.113501512 1512 1BB25
1988.11299 1512 1512 1BB26
Rl 1 I 67 1500
401,932 1418.1Lot 11
Rl 2 I 67 I 500
439,1004 1419.1Lot 10
Rl 3 I 67 I 500
489,1082 1421.1Lot 9
Rl 4 I 67 I 500
545,11651422.1Lot 8
Rl 5 I 67 I 500
579 1866 1433.1Lot 12a
Rl 6 I 67 I 500
589 1863 1433.1Lot 12b
Rl 7 I 67 I 500
639 1958 1435.1Lot 13
Rl 8 I 67 I 500
705 11042 1440.1Lot 14a
Rl 9 I 67 1500
713 11036 1440.1Lot 14b
Rl 10 I 67 1500
765 11109 1446.1Lot 15a
Rl 11 I 67 1500
773 11103 1446.1Lot 15b
Rl 12 I 67 I 500
833 11174 1453.1Lot 16a
Rl 13 I 671500
840 11167 1453.1Lot 16b
Rl 14 I 67 1500
955 112561464.1Lot 17a
Rl 15 I 67 I 500
961 11248 1464.1Lot 17b
Rl 16 I 67 I 500
1104112761472.,Lot 18
Rl 17 I 67 1500
117711293 1480.1Lot 19
Rl 18 I 67 1500
1688 1 1310 1 515.1 Lot 25
Rl 19 I 67 1500
1774 1 1315 1 517.1 Lot 26
Rl 20 I 67 1500
1892,1300 1 517.1 Lot 27
C 1 C
ELE 0 1 2 5 6 7 ID LENGTH TYPE
1 6.* B1 41.6 MASONRY
2 6.* B2 48.4 MASONRY
3 6.* B3 44.8 MASONRY
4 6. * B4 62.7 MASONRY
5 5.* B5 209.3 MASONRY
6 4. * B6 150.1 MASONRY
7 4. * B7 77.1 MASONRY
8 9.* W1 62.7 MASONRY
9 10.* W2 100.3 MASONRY
10 10.* W3 3.6 MASONRY
11 10.* W3b 120.4 MASONRY
12 10.* W4 5.4 MASONRY
13 10. * W5 90.9 MASONRY
14 10.* W6 6.3 MASONRY
15 10.* W7 94.2 MASONRY
16 10.* W8 7.5 MASONRY
17 10.* W8B 94.9 MASONRY
18 9.* W9 66.3 MASONRY
19 8.* W11 69.2 MASONRY
20 8. * W12 33.5 MASONRY
21 8 . * W14 80.0 MASONRY
22 8 . * W15 26.0 MASONRY
23 8. * W16 64.3 MASONRY
24 8. * W17 22.1 MASONRY
25 8.* W18 36.3 MASONRY
26 7 . * bb15b 19.7 MASONRY
27 7.* bb16 67.3 MASONRY
28 0.* BB17 57.8 BERM
29 0. * BB18 48.1 BERM
30 0.* BB19 90.6 BERM
31 0.* BB20 95.5 BERM
32 0.* BB21 153.3 BERM
33 0.* BB22 59.0 BERM
34 0.* BB23 109.2 BERM
35 0.* BB24 42.1 BERM
36 0. * BB25 90.7 BERM ------------------------------------------------------------------------------
0 1 2 3 4 5 6 7
1
REC REC ID DNL PEOPLE LEQ(CAL)
--------------------------------
1 Lot 11 67. 500. 58.5
2 Lot 10 67. 500. 58.4
3 Lot 9 67. 500. 57.5
4 Lot 8 67. 500. 56.2
5 Lot 12a 67. 500. 58.8
6 Lot 12b 67. 500. 59.5
7 Lot 13 67. 500. 59.1
8 Lot 14a 67. 500. 59.4
9 Lot 14b 67. 500. 60.3
10 Lot 15a 67. 500. 59.2
11 Lot 15b 67. 500. 60.1
12 Lot 16a 67. 500. 59.6
. 13 Lot 16b 67. 500-60.3
14 Lot 17a 67. 500. 59.9
15 Lot 17b 67. 500. 60.1
16 Lot 18 67. 500. 59.9
17 Lot 19 67. 500. 60.3
18 Lot 25 67. 500. 52.5
19 Lot 26 67. 500. 53.6
20 Lot 27 67. 500. 54.4 --------------------------------
BARRIER TYPE
BERM
MASONRY
MASONRY/JERSEY
CONCRETE
TOTAL COST = $
COST
0 .
110677.
0 .
0 .
111000.
-----------
BARRIER HEIGHT INDEX FOR EACH BARRIER SECTION
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1
CORRESPONDING BARRIER HEIGHTS FOR EACH SECTION
6. 6. 6. 6. 5. 4. 4. 9.10.10.10.10.10.10.10.10.10. 9. 8. 8. 8. 8. 8. 8. 8.
7. 7. 0. 0. 0. 0. 0. 0. 0. 0. 0.