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HomeMy WebLinkAboutPUD 2021-0001; GARFIELD HOMES; NOISE STUDY; 2020-11-01- ----- - - ---- - •• - --------- 4008 GARFIELD STREET RESIDENTIAL PROJECT NOISE STUDY Prepared for: Rincon Real Estate Group Prepared by: 4])G)© BIRDSEYE PLANNING GROUP November 2020 .!r,N i ~ 2D2\ \ , ·. • ,_~)'3AD r-, ·1 . ·" ::,,•,:1.-..--,;0\I - -- --------- --- - - ----- --- - • 4008 Garfield Street Noise Study Table of Contents Page Project Description ................................................................... ,. ................................................................ I Setting .......................................................................................................................................................... 1 Overview of Sound Measurement ................................................................................................. 1 Sensitive Receptors .......................................................................................................................... 4 Project Site Setting ............................................................................................................................ 5 Regulatory Setting ............................................................................................................................ 6 Impact Analysis .......................................................................................................................................... 7 Methodology and Significance Titresholds .................................................................................. 7 Temporary Construction Noise ...................................................................................................... 8 Construction Noise Reduction Measures ................................................................................... 10 Residual Impacts ............................................................................................................................ 10 Temporary Construction-Related Vibration .............................................................................. 11 Long-Term Operational Noise Exposure .................................................................................... 11 Conclusion ................................................................................................................................................ 14 References ................................................................................................................................................. 15 List of Figures Figure 1 -Project Location ....................................................................................................................... 2 Figure 2 -Proposed Site Plan ................................................................................................................... 3 List of Tables Table 1 -Noise Monitoring Results ........................................................................................................ 6 Table 2 -Typical Construction Equipment Noise Levels .................................................................... 9 Table 3 -Typical Maximum Construction Noise Levels at Various Distances from Project Construction .................................................................................................................. 9 Table 4 -Vibration Source Levels for Construction Equipment ....................................................... 11 Appendices Appendix A Noise Monitoring Data C)C)(i;) BIRDSEYE PlANN•tir. c.~o,w TOC ----- ----- --- - - - ----------- - 4008 Garfield Street Noise Study 4008 GARFIELD STREET CARLSBAD, CALIFORNIA NOISE STUDY This report is an analysis of the potential noise impacts associated with the 4008 Garfield Street project, a 3-unit condominium development proposed for construction in tl1e City of Carlsbad. TI1e report has been prepared by Birdseye Planning Group, LLC, under contract to the applicant to support the environmental review process and address comments provided by the City of Carlsbad after review of the project entitlement submittal. This study analyzes the potential for temporary impacts associated with construction activity and long-term impact<, associated with operation of the proposed project. PROJECT DESCRIPTION The project is located at the southeast comer of Garfield Street and Chinquapin Avenue. The project would replace an existing multifamily residence with a new 3-unit multifamily project. Construction would require the demolition and removal of the existing structure, installation of infra'>tructure improvements and construction of three, 3-story buildings. Construction is anticipated to begin in mid-2021 and be completed by late-2021. Figure 1 provides a vicinity map; Figure 2 shows a project site plan. SETTING Overview of Sound Measurement Noise level (or volume) is generally measured in decibels (dB) using the A-weighted sound pressure level (dBA). The A-weighting scale is an adjustment to the actual sound pressure levels to be consistent with that of human hearing response, which is most sensitive to frequencies around 4,000 Hertz (about the highest note on a piano) and less sensitive to low frequencies (below 100 Hertz). Sound pressure level is measured on a logarithmic scale with the 0 dB level based on the lowest detectable sound pressure level that people can perceive (an audible sound that is not zero sound pressure level). Based on the logarithmic scale, a doubling of sound energy is equivalent to an increase of 3 dBA, and a sound that is 10 dBA less than the ambient sound level has no effect on ambient noise. Because of the nature of the human ear, a sound must be about 10 dBA greater than the reference sound to be judged as twice as loud. In general, a 3 dBA change in community noise levels is noticeable, while 1-2 dB changes generally are not perceived. Quiet suburban areas typical1y have noise levels in the range of 40-50 dB A, while arterial streets are in the 50..60+ dBA range. Normal conversational levels are in the 60-65 dBA range, and ambient (i)~© BIRDSEYE !-'IA'-,mK,GROU~ 1 Figure 1-Vicinity Map Figure 2-Site Plan ·-··-··-··-··-··-··-··-··-··-··-·_J .. r- I • COHCEPTUAI. SITE PUii r. / ' ' ' I ' I i I ' I I ' ' l I --' I ' • ' ...... ! .. · "' I I-· I j I ' ,-' ! .. , ~ .. , ...... N --------·----··•l;iMllt ·-.. . ~ ....... v .. ===-=.--- :-:... ==-... ' . .. . . -----------...... II) -ILi J 0 --- -- :J:9< 0 u .J II • al w"'J ... a: ~~~ ~. er: C) ! ~ A1.1 4008 Garfield Street Noise Study noise levels greater than 65 dBA can interrupt conversations. Noise levels typically attenuate (or drop off) at a rate of 6 dBA per doubling of distance from point sources (i.e., industrial machinery). Noise from lightly traveled roads typically attenuates at a rate of about 4.5 dBA per doubling of distance. Noise from heavily traveled roads typically attenuates at about 3 dBA per doubling of distance. Noise levels may also be reduced by intervening structures; generally, a single row of buildings between the receptor and the noise source reduces the noise level by about 5 dBA, while a solid wall or berm reduces noise levels by 5 to 10 dBA. The manner in which older homes in California were constructed (approximately 30 years old or older) generally provides a reduction of exterior-to-interior noise levels of about 20 to 25 dBA with closed windows. The exterior-to-interior reduction of newer residential units and office buildings is generally 30 dBA or more (HMMH, 2006). In addition to the actual instantaneous measurement of sound levels, the duration of sound is important since sounds that occur over a long period of time are more likely to be an annoyance or cause direct physical damage or environmental stress. One of the most frequently used noise metrics that considers both duration and sound power level is the equivalent noise level (Leq). The Leq is defined as the single steady A~weighted level that is equivalent to the same amount of energy as that contained in the actual fluctuating levels over a period of time (essentially, the average noise level). Typically, Leq is summed over a one-hour period. Lmax is the highest RMS (root mean squared) sound pressure level within the measuring period, and Lmin is the lowest RMS sound pressure level within the measuring period. The time period in which noise occurs is also important since noise that occurs at night tends to be more disturbing than that which occurs during the day. Community noise is usually measured using Day-Night Average Level (Ldn), which is the 24~hour average noise level with a lO~dBA penalty for noise occurring during nighttime (10 p.m. to 7 a.m.) hours, or Community Noise Equivalent Level (CNEL), which is the 24-hour average noise level with a 5 dBA penalty for noise occurring from 7 p.m. to 10 p.m. and a 10 dBA penalty for noise occurring from 10 p.m. to 7 a.m. Noise levels described by Ldn and CNEL usually do not differ by more than 1 dB. Sensitive Receptors Noise exposure goals for various types of land uses reflect the varying noise sensitivities associated with ead1 of these uses. The City of Carlsbad General Plan Noise Element Update (approved September 2015) includes a variety of land use and development types that are noise sensitive including residences, schools, churches, hospitals and convalescent care facilities. Sensitive receptors are located adjacent to the project site. Once constructed, the project will be a sensitive receptor. Single-and multifamily residences are the dominant land use in the area. (l)Q© BIRDSEYE HAl'.NIN(; C',ROUP -------- - - --- ----- - -- • 4 • - - •· ----------- --- --- - ------ • 4008 Garfield Street Noise Study Project Site Setting The most common and primary sources of noise in the project site vicinity are motor vehicles (e.g., automobiles, buses, trucks, and motorcycles) along Garfield Street and Chinquapin Avenue. Motor vehicle can be a concern when it is characterized by a hlgh number of individual events that can create a sustained noise levc-1 in proximity to noise sensitive uses. Interstate 5 is located approximately 2,500 feet to the east. Tt is not audible as a discrete noise source and does not contribute to overall noise levels at the project site. The Atichson, Topeka and Santa Fe Railroad (AT&SF) rail corridor is located approximately 800 feet east of the site. This segment of the Los Angeles -San Diego -San Luis Obispo (LOSSAN) corridor is the second busiest passenger and freight rail corridor in the United States. According to the rail timetables, up to 50 trains (40 passenger and 10 freight trains) use the corridor segment daily between Oceanside and the Santa Fe Depot in downtown San Diego. Existing rail locomotive pass by events are audible at the project site as are the warning horns/bells that are used when trains are traveling between Poinsettia Station located 2.7 miles to the south and Carlsbad Village Station located approximately 1.1 miles north of the site. Train noise contributes to the ambient noise environment in the study area. McClellan-Palomar Airport is located approximately 3.5 miles southeast of the site. The site is outside the airport influence area; however, aircraft operations (airplanes and helicopters) arc audible and contribute to existing noise levels in the project area. No other noise sources are near the project site. The City of Carlsbad General Plan Update Noise Element (2015) provides noise contours associated with transportation corridors (i.e., roadways, railroad and airport). lhis provides a graphic illustration of sound levels near road corridors, but typically does not include effects of landforms and adjacent s.tructures. Generally, barriers between a source and receiver absorb or reflect noise resulting in a quieter environment. Where barriers or landforms do not interrupt the noise transmission path from source to receiver, the contours prove to be reasonable estimates of typical noise levels from roadway traffic. In areas where barriers or landforms interrupt the sound transmission, the noise contours overestimate the extent to which a source intrudes into neighboring areas. The noise contour distances describe worst-case conditions because they do not account for any obstructions to the noise path, such as walls, berms, or buildings. As noted, railroad noise is audible when train pass-by events occur. The contours provided in the General Plan Update Noise Element provide a reasonable prediction of rail noise levels at the site. Noise contours show the project site is outside the 60-65 dBA CNEL contour interval defined for the railroad track and outside the 60-65 dBA CNEL contour line for 1-5. To gather data on the general noise environment at the project site, one weekday 15-minute noise measurement was acquired at the project site on November 4, 2020, using an ANSI Type II integrating sound level meter. The predominant noL<,e source in the area during monitoring was traffic on Garfield Street and Chinquapin Avenue. Aircraft overflights and a train pass by event contributed to ambient conditions during the November 4 monitoring period. 0Q© BIRDSEYE Pl ANNING G~<:,J? 5 4008 Garfield Street Noise Study During monitoring, a total of 32 cars/light trucks passed the monitoring site. One Coaster commuter train, two helicopter overflights and one airplane overflight occurred during monitoring. Table 1 identifies the noise measurement location and measured noise levels. As shown, the measured Leg's were within 2 dBA. Monitoring data is provided as Appendix A. Table 1 Noise Monitoring Results Measurement Location Primary Noise Sample Time Leq (dBA) Source Project site located 4008 Garfield Street (11/04/2020) Traffic/Rail/Aircraft Weekday afternoon 54.8 Source: Field visit using ANSI Type II Integrating sound level meter. Regulatory Selling In 1976, the California Department of Health, State Office of Noise Control published a recommended noise/land use compatibility matrix which many jurisdictions have adopted as a standard in their general plan noise elements. This matrix indicates that residential land uses and other noise sensitive receptors preferentially should be located in areas where outdoor ambient noise levels do not exceed 65 to 70 dBA (CNEL or Ldn). Municipal Code and Noise Guideline Manual The City of Carlsbad has established noise guidelines in the Noise Element of the City's General Plan (City of Carlsbad, 2015) that are applicable for transportation noise sources. The noise guidelines identify compatible exterior noise levels for various land use types. Residential land uses are considered normally acceptable up to 60 dB CNEL. Commercial land uses are considered normally acceptable up to 65 dB CNEL and conditionally acceptable up to 75 dB. The City of Carlsbad Municipal Code regulates construction noise by limiting the hours of operation (City of Carlsbad 2003). Construction activities are allowed to occur Monday through Friday between the hours of 7 a.m. to sunset; and on Saturdays from 8 a.m. to sunset, excluding legal holidays. The City does not have quantitative noise level limits (i.e., based on sound levels) for general nuisance noise such as that associated with stationary equipment located on private property. For the purpose of this study, the residential standard of 60 dB CNEL is used to evaluate potential exterior noise impacts associated with the proposed project. An interior noise standard of 45 dBA CNEL is used herein as referenced in the City of Carlsbad Noise Guidelines Manual (1995). C)Q@ BIRDSEYE Pt ,._r,,NlNG (,1101.J? ---.. -.. -.. -.. -.. -.. -.. -.. -.. .. .. .. .. .. .. .. -.. .. .. .. -.. - 6 .. -.. -- - -- -- - - - - - ----- --- - - - 4008 Garfield Street Noise Study Vibration Standards Vibration is a unique form of noise as the energy is transmitted through buildings, structures and the ground whereas audible noise energy is transmitted through the air. Thus, vibration is generally felt rather than heard. The ground motion caused by vibration is measured as particle velocity in inches per second and is referenced as vibration decibels (VdB). The vibration velocity level threshold of perception for humans is approximately 65 VdB. A vibration velocity of 75 VdB is the approximate dividing line between barely perceptible and distinctly perceptible levels. City policies do not address construction-related vibration; thus, for the purpose of evaluating project-related vibration impacts, thresholds establL">hed in the Federal Transit Administration's (FTA) Transit Noise and Vibration Impact Assessment (May 2006) are used. A threshold of 65 VdB is used for buildings where low ambient vibration is essential for interior operations. These buildings include hospitals and recording studios. A threshold of 72 VdB is used for residences and buildings where people normally sleep (i.e., hotels and rest homes). A threshold of 75 VdB is used for institutional land uses where activities occur primarily during the daytime (i.e., churches and schools). The threshold used for the proposed project is 72 VdB as multifamily residences are the only sensitive receptors in proximity to the site. Construction activities such as blasting, pile driving, demolition, excavation or drilling have the potential to generate ground vibrations near structures. With respect to ground-home vibration impacts on structures, the FTA states that ground-borne vibration levels in excess of 100 VdB would damage fragile buildings and levels in excess of 95 VdB would damage extremely fragile historic buildings. No historic buildings are known to occur near the site; thus, 100 VdB is used to quantify potential vibration impacts to neighboring structures. Construction activities referenced above that would generate significant vibration levels are not proposed. However, to provide information for use in completing the CEQA evaluation, construction-related vibration impacts are evaluated using the above referenced criteria. IMPACT ANALYSIS Methodology and Significance Thresholds Construction noise estimates are based upon noise levels reported by the Federal Transit Administration, Office of Planning and Environment, and the distance to nearby sensitive receptors. Reference noise levels from that document were used to estimate noise levels at nearby sensitive receptors based on a standard noise attenuation rate of 6 dB per doubling of distance (line-of-sight method of sound attenuation). The site is currently a single-family residence; thus, noise levels associated with existing and future traffic were based on the difference in trip volumes between the existing volumes (l)Q© BIRDSEYE 7 4008 Garfield Street Noise Study counted during monitoring and the proposed use. A doubling of traffic volumes would be required to cause a noticeable increase (3 dBA) in traffic noise. Thus, the two numbers were calculated to determine whether the project would generate enough traffic to increase noise levels by 3 dBA or more. This study also estimates potential noise levels at the project site related to operation of the AT&SF rail line which is located approximately 800 feet east of the site. A software program based on methodologies approved by the Federal Rail Administration was used to perform noise calculation associated with rail operations. Specific assumptions used in the analysis are described below. As noted, a noise increase greater than 3 dBA is readily perceptible to the average human ear; and thus, is the level considered a substantial noise increase related to traffic operations. However, within the City of Carlsbad, noise impacts are also considered significant if noise levels would exceed 60 dBA CNEL. For the purpose of this evaluation, the peak hour Leq is used for traffic noise as it provides a more conservative estimate of potential noise levels. The CNEL is used within the rail noise discussion. Existing noise levels at the monitoring site do not exceed 60 dBA as referenced above; thus, the determination of impact is based on whether existing noise levels would increase and/or cause noise levels to exceed 60 dBA with project implementation. All mechanical equipment associated with the project would be located within roof top enclosures or within each unit. Mechanical noise is not expected to be audible on-or off-site. Temporary Construction Noise The main sources of noise during construction activities would include heavy machinery used during demolition, grading, and clearing the site, as well as equipment used during building construction and paving. Table 2 shows the typical noise levels associated with heavy construction equipment. As shown, average noise levels associated with the use of heavy equipment at constmction sites can range from 81 to 95 dBA at 25 feet from the source, depending upon the types of equipment in operation at any given time and phase of construction (Hanson, Towers, and Meister, May 2006). As noted, adjacent properties are residential and construction noise will be audible at properties in proximity to the site. Table 3 shows typical maximum construction noise levels at various distances from construction activity, based on a standard noise attenuation rate of 6 dBA per doubling of distance. The site is small which limits the equipment that can be used; thus, noise level used to estimate the maximum noise level that could occur is based on use of a bobcat or backhoe tractor as it is likely to be the noisiest type of equipment used over a sustained period of time during demolition and site preparation activities. Actual noise levels will fluctuate throughout the day and may periodically exceed 84 dB A at the property line depending on the type and location of equipment used and whether multiple pieces of equipment are operating simultaneously in the same area. G)~@ BIRDSEYE .. .. .. ---.. .. -.. .. .. .. ... .. ◄ -.. -.. -.. -... -.. -.. -.. .. .. -.. - 8 -.. - --- ----- -.. - --- --- --- ----------- 4008 Garfield Street Noise Study T rvnca Table 2 iD Construction E ui ment Noise Levels Typical Level Typical Level (dBA) Typical Level (dBA) Equipment Onslte (dBA} 25 Feet 50 Feet from the 100 Feet from the from the Source Source Source Air Compressor 84 78 84 Backhoe 84 78 84 Bobcat Tractor 84 78 64 Concrete Mixer 85 79 73 Bulldozer 88 82 76 Jack Hammer 95 89 83 Pavement Roller 88 80 74 Street Sweeper 88 82 76 Man Lift 81 75 89 Dump Truck 82 76 70 Source: Noise levels based on FHWA Roadway Construct/on NOJse Mode/ (2006) Users Gwde Table 1. Noise levels based on actual maximum measured noise levels at 50 feet (Lmax) Noise /e',/e/s assume a noise attenuation rate of 6 dBA per doubling of distance. Table 3 Typical Maximum Construction Noise Levels at Various Distances from Project Construction Distance from Maximum Noise Level at Construction Receptor (dBA) 251eet 84 50 feet 78 100 feet 72 250 feet 66 500 feet 60 1,000 feet 54 Construction noise levels at neighboring residences could be as high as 84 dBA. However, temporary con..<;truction noise is not restricted if it occurs between the hours specified in the noise ordinance referenced herein. While not required, temporary construction noise can be reduced by implementing one or more of the following measures. 00@ BIRDSEYE fl M,NING (;ROUP 9 4008 Garfield Street Noise Study Construction Noise Reduction Measures Temporary construction noise impacts could be reduced through implementation of the following measures: N-1 N-2 N-3 Residual Impacts Construction Equipment. Electrical power shall be used to run air compressors and similar power tools. Internal combustion engines should be equipped with a muffler of a type recommended by the manufacturer and in good repair. All diesel equipment should be operated with closed engine doors and should be equipped with factory-recommended mufflers. Construction equipment that continues to generate substantial noise at the project boundaries should be shielded with temporary noise barriers, such as barriers that meet a sound transmission class (STC) rating of 25, sound absorptive panels, or sound blankets on individual pieces of construction equipment. Stationary noise-generating equipment, such as generators and compressors, should be located as far as practically possible from the nearest residential property lines. Limit Operations Adjacent to Receivers. Limit the number of large pieces of equipment (i.e., backhoes or concrete mixers) operating adjacent to receivers to one at any given time. Neighbor Notification. Provide notification to residential occupants nearest to the project site at least 24 hours prior to initiation of construction activities that could result in substantial noise levels at outdoor or indoor living areas. This notification should include the anticipated hours and duration of construction and a description of noise reduction measures being implemented at the project site. The notification should include a telephone number for local residents to call to submit complaints associated with constmction noise and be easily viewed from adjacent public areas. Project construction would represent a temporary source of noise at the project site. Measures N-1 through N-3 could reduce construction noise impacts. No residual impacts associated with construction noise are anticipated. 00>© BIRDSEYE Pi.ANNING G'10V? .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 10 .. .. .. --- -----.. ------- - - - ----- --- - 4008 Garfield Street Noise Study Temporary Construction-Related Vibration Activities associated with residential projects do not generate vibration. Thus, this discussion will focus on temporary vibration caused by construction. Based on the information presented in Table 4, vibration levels could reach 87 VdB at the buildings nearest the site during construction assuming a small bulldozer is the heaviest piece of equipment used during demolition. As discussed below, 100 VdB is the threshold where minor damage can occur in fragile buildings. Vibration levels are projected to be under this threshold; thus, structural damage is not expected to occur as a result of construction activities associated with the proposed project. Vibration levels at residential buildings adjacent to the project site, provided a small bulldozer is the largest piece of equipment used, would not exceed the groundbome velocity threshold level of 72 VdB for residences and/or buildings where people sleep as discussed above. While maximum vibration levels would range from 58 to 87 VdB depending on the type of equipment used, as long as construction occurs within the prescribed hours, any temporary impact would be considered adverse, but less than significant. Table 4 Vibration Source Levels for Construction Equipment Equipment Approximate VdB 25 Feet 50 Feet 60 Feet 75 Feet 100 Feet Large Bulldozer 87 81 79 77 75 Loaded Trucks 86 80 78 76 74 Jackhammer 79 73 71 69 67 Small Bulldozer 58 52 50 48 46 Source: Federal Railroad Administration, 1998 Long-Term Operational Noise Exposure Exterior Traffic Noise. Traffic is the primary noise source that would be generated by the proposed project. Thus, whether a traffic•related noise impact would occur is based on whether the project would double peak hour traffic volumes relative to existing conditions or cause noise levels to exceed 60 dBA. The peak hour is defined as the one-hour period between 7:00 am and 9:00 am and 4:00 pm and 6:00 pm when the highest volumes occur. Traffic volumes for the project were based on evening peak hour trip generation rates published by the Institute of Transportation Engineers (ITE) publication Trip Generation, 1011' Edition for condominiums/apartments. Using a trip generation rate of 6 daily trips per unit, the project C)Q@ BIRDSEYE Pl A Ml ING G~0>1" l] 4008 Garfield Street Noise Study would generate 18 daily trips. Peak hour trips are assumed to be 0.62 trips per unit or 3 hourly trips. Existing peak hour volumes based on November 4, 2020 counts performed during noise monitoring, are 28 vehicles cm Garfield Street and 5 on Chinquapin Avenue. Thus, peak hour project trips (3) would not double existing volumes nor, based on existing noise levels, would the additional of project traffic have an adverse effect on noise levels at sensitive properties within proximity to the site. Project impacts with respect to exterior traffic noise would be less than significant. Interior Traffic Noise. The proposed project would be designed to meet or exceed California Energy Code Title 24 standards which specify construction methods and materials that result in energy efficient structures and up to a 30 dBA reduction in exterior noise levels (assuming windows are closed). When windows are open the insertion loss drops to about 10 dBA. Assuming windows are closed, interior noise levels associated with traffic operations would be reduced from 54.8 (baseline) to 24.8 dBA which would be below the 45 dBA standard. Exterior Railroad Noise. The AT &SF corridor is located approximately 800 feet to the east of the site and is used by Amtrak and the North County Transit District Coaster to provide passenger rail service. It is also used by freight trains during the late evening and nighttime hours. Based on the timetables, approximately 26 passenger trains currently operate within this segment; however, historically, up to 40 passenger trains have used the corridor daily. Assuming a worst case scenario, up to 40 passenger trains and 10 freight train'> operate daily within this segment. Train volumes vary throughout the day but are generally higher during the morning and evening commute hours and reflect the dominant use of this corridor by commuter rail and passenger trains. Train noise is generated by a combination of factors including the number of locomotives, rail cars, speed, volume distribution over the day and nighttime hours and whether train horns arc used. Hte existing rail noise levels at the project site were calculated using a proprietary sofhvare program based on Federal Rail Administration methodology. Because trains often stop at the Carlsbad Village Station and Poinsettia Station (Amtrak and freight trains do not), it was assumed the average track speed in proximity to the site is 40 miles per hour. Further, it was assumed that each passenger train has one locomotive and 10 rail cars. For freight trains it was assumed they have two locomotives and 50 cars. Train warning horns/bells were audible during monitoring; thus, it was assumed that train operators do use the warning horn when in proximity to the site. Of the approximately 50 train pass by events each day, five freight operations were assumed to occur during the nighttime (10:00 p.m. to 7:00 a.m.) hours. Based on these assumptions, the exterior CNEL at the project site (located 800 feet west of the rail corridor) is approximately 56.4 when both passenger and freight rail operations are combined. This does not consider the inten,ening topography and structures that likely attenuate noise levels between the rail corridor and the project site. The estimated CNEL 56.4 is outside the 60- 65 dBA CNEL contours provided in the 2015 General Plan Update Noise Element for residential areas within the City of Carlsbad and would not exceed the recommended CNEL for residential uses. G)(J>@ BIRDSEYE -... .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. ... --.. .. -.. -.. -.. .. 12 --- --- - ------------ -- - ------- - - -- 4008 Garfield Street Noise Study Interior Railroad Noise. While the existing exterior CNEL at the site does not exceed the standard recommended by the City of Carlsbad for residential uses, design features can be implemented to further reduce interior noise levels to at least 45 dBA CNEL as specified in the City of Carlsbad Noise Guidelines Manual. As noted above, the proposed project would be designed to meet or exceed California Energy Code Title 24 standards which specify construction methods and materials that result in energy efficient structures and up to a 30 dBA reduction in exterior noise levels (assuming windows are closed). Assuming windows are closed, the CNEL associated with rail noise would be reduced from 56.4 dBA CNEL to 26.4 dBA CNEL which would be consistent with the local standards. No measures in addition to compliance with Title 24 design requirements would be necessary to reduce rail noise. Rail Vibration. As noted, the proposed project would be constructed approximately 800 feet west of the rail corridor. Thus, a screening evaluation of potential vibration impacts was performed to determine whether the project would be exposed to vibration levels that could be perceived by building residenls. Because the project i.<; a residential development, it would be considered a Category 2 land use for the purposes of vibration assessment as defined in the Fedt'ral Transit Administration, Transit Noise and Vibration Impact Assessment (2018). This category covers all residential land uses and any buildings where people sleep, such as hotels and hospitals. The impact criteria for a Category 2 land use is 75 VdB along heavily used corridors (i.e., more than 12 events daily). As noted, a vibration velocity of 75 VdB is the approximate dividing line between barely perceptible and distinctly perceptible levels. A screening level evaluation was performed to determine the likelihood of vibrations from the LOSSAN corridor affecting the proposed project. The screening distance for conventional commuter railroads was used to account for both passenger and freight trains. The distance between a conventional commuter railroad and Category 2 land u5e where the potential for a vibration impact to occur is 200 feet as defined in Table 6.8 within the FTA noise and vibration impact assessment methodology referenced above. The screening distances include a 5-decibel safety factor. The proposed project site is located outside the 200-foot screening distance; however, a general vibration assessment was performed to provide a more detailed evaluation of potential vibration impacts. The general vibration assessment methodology is provided in Chapter 6 of the assessment manual identified above. It is based on the use of a base curve to determine vibration as a function of distance from the track assuming a standard rail and ballast configuration. Using the diesel powered locomotive powered passenger or freight base curve (see Figure 6-4 in the federal Transit Administration, Transit Noise and Vibration Impact Asseio!:>ment Manual), the vibration level is 68.0 VdB at approximately 300 feet from the track at a reference speed of 50 miles per hour. Using a rnrrcction factor of 2 VdB for speed (40 in the study area vs. a 50 VdB reference level), the vibration level at 300 feet is estimated to be 67 VdB. This is likely conservative given the amount of ballast rock in the track bed and soil propagation. The site is €}Q@ BIRDSEYE P\ ~NNING (;~00~ 13 4008 Garfield Street Noise Study 800 feet from the tracks; and thus, for the purpose of assessing potential vibration levels, projected vibration levels would not exceed the 72 VdB threshold. Conclusion The proposed project would be constructed within an existing residential area and replace an existing residential use. The measured noise level at the project site is approximately 54.8 dBA Leq. Ambient conditions are dominated by traffic on Garfield Street and Chinquapin Avenue; however, train pass by events and aircraft overflights are audible. The project would add approximately 18 daily trips and 3 peak hour trips. The addition to project traffic to the existing conditions would not change noise levels; and thus, not cause an exceedance of the City of Carlsbad standards. As noted, train pass by events are audible but noise attenuates to below noise standards for residential uses. The project would have no adverse impact on existing noise levels nor would it be exposed to noise levels that exceed City of Carlsbad standards for residential uses. C)~© BIRDSEYE Pl ,._t'<NING (;ROlW .. -.. ---.. -.. ... -... .. ... .. ... - ,◄ ---.. .. -.. .. .. ... .. .. .. ---- 14 .. -.. - --- - ------------------------------ 4008 Garfield Street Noise Study References City of Carlsbad. General Plan Update Noise Element. 2015. City of Carlsbad. Noise Guidelines Manual. September, 1995. Federal Highway Administration. Roadway Construction Noise Model. 2006. Users Guide Table 1. Federal Highway Administration, Transportation Noise Model Version 2.5, 2004. Federal Transit Administration. Transit Noise and Vibration Impact Assessment. September 2018. Federal Rail Administration (FRA) Guidelines (Report Number 293630~1), December 1998. Hanson, Carl E., Towers, David A., and Meister, Lance D. (2006, May). Transit Noise and Vibration Impact A.;sessment. Federal Transit Administration, Office of Planning and Environment. btt;p;/!www.fta.dot.gov/documents)FTA Noise and Vibration Manual.pdf Harris Miller Miller & Hanson Inc. Transit Noise and Vibration Impact A.;,se~sment, Final Report. May 2006. Institute of Transportation Engineers (ITE) publication Trip Generation, 1011' Edition (i)@© BIRDSEYE FlA'-N<NG (;~Ocl<' 15 (i)Q@ BIRDSEYE Appendix A Monitoring Data Sheet Appendix A .. .. ... ... ... ... ... ... .. ... ... -----.. - - - - --------- ---------~- - • -- FIELD NOISE 1'1'.EASUREMl::N l UAlA i ! t l I ; __ Ir' ---t----t-1 __ ·-t'----+·--+---+ ' '- !\lumber of Lanes 7 Width (pave/row) • 7~<-f, 1-or2-way L ·/ ,-;-Grade/ ~ 7/ , -.. Bus Stops µ .. ,(.; Stoplights .,,._J [.,,i Stre.st Parking lf,:f. At.<iomobiles . ..,. ) c:, Medium Trucke <£-1 Heavy Trucks 0 ·-. l.50 L90 . ·----f- ----+-! i . ' I j . . ! opo: , . :wind: . ' W111d Spd/ Temp Dir(mph) [°F) I L -z. til· f?Y,,;' . ---·· ------. .-----. --. ' . Page i ,Jf escn ' -~· """' I • '/ Gu ! J ' RH BarPsr Ctoud (%) (in Hg) Cover(%) c··/ ' .. ' . ·, ~ ' I j ' ' ; ' r I .. ... .. Site 1 -4008 Garfield Street .. Start Date 11/4/2020 .. start Time 3:29:17 PM End Time 3:44:16 PM .. Duration 00: 14: 59 Meas Mode Single .. Input Range Low .. Input Type Mic SPL Time Weight Slow .. LN% Freq Weight dBA .. overload No UnderRange No .. sensitivity 18.44mV/Pa ... LZeq 70.0 .. LCeq 67,7 LAeq 54.8 .. LZSmax 85.0 LCSmax 84.3 .. LASmax 69.7 .. LZSmin 63.4 LCSmin 61.3 .. LASmin 43.5 LZE 99.5 ◄ LCE 97.2 .. LAE 84.3 LZpeak 95.4 .. LCpeak 96.2 LApeak 90.1 .. 1% 65.0 .. 2% 63.9 5% 61.3 .. 8% 59.8 .. 10% 59.0 25% 53.8 .. 50% 48.0 90% 45.0 .. 95% 44.6 99% 44.1 .. .. .. .. .. .. .. • .. .. .. ..