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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.