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CT 2024-0001; TYLER STREET HOMES - SB 330; NOISE STUDY; 2024-10-01
3215-3225 TYLER STREET RESIDENTIAL PROJECT NOISE STUDY Prepared for: KMJ Real Estate 2888 Loker Ave. E Suite 220 Carlsbad, CA Prepared by: October 2024 €)G)© 81 IRDSEYE PILANIN IINGi GiR ,QUP 3215‐3225 Tyler Street Residential Project Noise Study ES-1 EXECUTIVE SUMMARY The project site is 0.53 acres in size and located at 3215‐3225 Tyler Street which is generally southwest of the intersection with Pine Avenue (APN 204‐010‐09). The project would remove two existing single‐family residences, vegetation and various outbuildings and construct 12 new three‐story units within four triplex buildings. The units would range between 2,176 and 2,302 square feet. Each unit would have an attached two‐car garage and private open space. Construction is anticipated to begin in late‐2024 and be completed in late 2025. 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. Construction noise levels at neighboring residences could be as high as 78 dBA at the property line. However, temporary construction noise is not restricted if it occurs between the hours specified in the noise ordinance. Operational Noise Traffic. Project traffic would add approximately 0.7 dBA to the baseline traffic conditions. Noise levels at the receivers along Tyler Street would be less than the 60‐dBA standard. The addition of 6 peak hour project trips to baseline traffic volumes would increase noise levels but have no noticeable effect (i.e., +/‐ 3 dBA) on noise levels at the modeled receivers. Exterior Railroad Noise. The AT&SF corridor is located approximately 250 feet west 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. The exterior Community Noise Equivalent Level (CNEL) at the western project site boundary is approximately 65.2 dBA when both passenger and freight rail operations are combined. The City of Carlsbad Noise Guidelines Manual states that noise levels within outdoor open space areas should not exceed 60 dBA CNEL. All outdoor open space requirements, with the exception of Units 5 and 11, would be met within the ground floor private yard areas provided for each unit. Outdoor common areas would be provided between buildings A and C and between buildings B and D. Construction of the six‐foot high vinal privacy fence along the western property boundary would reduce noise levels by approximately 8 dBA provided mass loaded, gap free panels are used and there are no gaps under the fence or at the tie in points with the buildings or fence sections along the north and south sides of the site. With respect to the second‐floor balconies constructed as part of Unit 5 and 11, the outdoor open space will be screened by Units 6 and 12 to the west which would provide approximately 10 dBA of attenuation. This would reduce outdoor open space noise to approximately 55 dBA CNEL. No project design features would be required to meet the 60 dBA standard. As stated, the outdoor common space would be located 3215‐3225 Tyler Street Residential Project Noise Study ES-2 near the center of the site between the townhome buildings. The buildings and distance from the railroad tracks would provide adequate screening/attenuation such that the outdoor open space standard would be met at these locations. Temporary Construction‐Related Vibration. As referenced, the closest residences to the site are approximately 50 feet east of the site. Additional residences are located to the north and south of the site on the east side of Tyler Street. Vibration levels from operation of a large bulldozer would conservatively be 87 VdB (0.089 inches/second) or less at 50 feet. Grading within 50 feet of the nearest residential structures would be required. As discussed, a PPV of 0.2 inches/second (100 VdB) is the vibration energy required to damage fragile historic buildings. While vibration from grading may be perceived at neighboring residences, the vibration energy would be well below that required to cause structural damage. Operational Vibration. The proposed project is a multistory residential apartment building. These uses do not generate vibration; thus, no vibration impacts are anticipated to occur with operation of the project. Operational vibration would be less than significant. Airport Operations. McClellen‐Palomar Airport is the nearest airport and is located approximately 4.0 miles southeast of the project site. Based on the noise contour maps provided in the McClellen‐Palomar Airport Land Use Compatibility Plan, Exhibit III‐1, the project site is located outside the 60 dB CNEL contour and is not affected by airport noise. For this reason, the project site is not located in an area affected by aircraft noise; and thus, compatibility with an adopted Airport Land Use Compatibility Plan is not required. 3215-3225 Tyler Street Residential Project Noise Study City of Carlsbad Table of Contents Page Project Description ..................................................................................................................................... 2 Setting .......................................................................................................................................................... 2 Overview of Sound Measurement ................................................................................................. 2 Sensitive Receptors .......................................................................................................................... 5 Project Site Setting ............................................................................................................................ 7 Regulatory Setting ............................................................................................................................ 8 Impact Analysis ........................................................................................................................................ 10 Methodology and Significance Thresholds ................................................................................ 10 Temporary Construction Noise .................................................................................................... 11 Construction Noise Reduction Measures ................................................................................... 12 Residual Impacts ............................................................................................................................ 13 Temporary Construction-Related Vibration .............................................................................. 13 Long-Term Operational Noise Exposure .................................................................................... 14 References ................................................................................................................................................. 21 List of Figures Figure 1 - Project Location ........................................................................................................................ 3 Figure 2 – Proposed Site Plan ................................................................................................................... 4 Figure 3 – Noise Monitoring Locations ................................................................................................... 9 Figure 4 – Sensitive Properties ............................................................................................................... 16 List of Tables Table 1 – Sound Levels of Typical Noise Sources and Noise Environments ..................................... 6 Table 2 – Noise Monitoring Results......................................................................................................... 8 Table 3 – Typical Construction Equipment Noise Levels .................................................................. 11 Table 4 – Typical Maximum Construction Noise Levels at Various Distances from Project Construction ................................................................................................................ 12 Table 5 – Vibration Source Levels for Construction Equipment ....................................................... 14 Table 6 – Modeled Noise Levels ............................................................................................................ 15 Appendices Appendix A Noise Monitoring Data @&© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 2 City of Carlsbad 3215-3225 TYLER STREET RESIDENTIAL PROJECT CARLSBAD, CALIFORNIA NOISE STUDY This report is an analysis of the potential noise impacts associated with the construction and operation of 12 new three-story duplex units and single-family units at 3215-3225 Tyler Street in the City of Carlsbad. The 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 impacts associated with operation of the proposed project. PROJECT DESCRIPTION The project site is 0.53 acres in size and located at 3215-3225 Tyler Street which is generally southwest of the intersection with Pine Avenue (APN 204-010-09). The project would remove two existing single-family residences, vegetation and various outbuildings and construct 12 new three-story units within four triplex buildings. The units would range between 2,176 and 2,302 square feet. Each unit would have an attached two-car garage and private open space. Construction is anticipated to begin in late-2024 and be completed in late 2025. 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 typically have noise levels in the range of 40-50 dBA, while arterial streets are in the 50-60+ dBA range. Normal conversational levels are in the 60-65 dBA range, and ambient noise levels greater than 65 dBA can interrupt conversations. Noise levels typically attenuate (or @O© BIRDSEYE PLANNING GROUP Figure 1—Vicnity Map - Project Site Figure 2—Site Plan -~1U/aXUlf ~-- CONCEPTUAL SITE PLAN I I t _____J ~ N 56"00'01" E 159.76' (159.~' R1) 8: 0 ,-10' 'rl'- I .~ I '-, '" ~ I @ ! ,. i" I t JI" i l : '' ~c~}--~---- Mf "'~ f~1J '· 67 l ':i:~: j ~ aa lil" :::o • • tn rf{lff.?s ~ . -; ,. i " N t:i· &, ~if ' ' -.;i., ~ :J ~"+ 2P' -! f40' -j =4::, 1' C-5•,_ ___ _ l=,:Oi f : i I en w ~ 0 :::c: I-w w a::: I-en a::: w ...J >-I- --& SITE PLAN I-w w 0:: I-C0 en 0 0 0:: "' w a, ..J <( ~ u "' ci "' <( "' al M en ..J "' 0:: N <( M u A1.1 3215-3225 Tyler Street Residential Project Noise Study 5 City of Carlsbad 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. 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 10-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. Table 1 shows sounds levels of typical noise sources measured using Leq. Sensitive Receptors Noise exposure goals for various types of land uses reflect the varying noise sensitivities associated with each 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 and surrounding the project site to the east. The closest is a multi-family residential building located at 515/517 Tyler Street across Tyler Street from the project site. Commercial development is located adjacent to and both north and south of the site. A vacant parking lot is located adjacent to the site to the west. @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 6 City of Carlsbad Table 1. Sound Levels of Typical Noise Sources and Noise Environments Noise Source (at Given Distance) Noise Environment A-Weighted Sound Level (Decibels) Human Judgment of Noise Loudness (Relative to Reference Loudness of 70 Decibels*) Military Jet Takeoff with Afterburner (50 ft) Carrier Flight Deck 140 128 times as loud Civil Defense Siren (100 ft) 130 64 times as loud Commercial Jet Take-off (200 ft) 120 32 times as loud Threshold of Pain Pile Driver (50 ft) Rock Music Concert Inside Subway Station (New York) 110 16 times as loud Ambulance Siren (100 ft) Newspaper Press (5 ft) Gas Lawn Mower (3 ft) 100 8 times as loud Very Loud Food Blender (3 ft) Propeller Plane Flyover (1,000 ft) Diesel Truck (150 ft) Boiler Room Printing Press Plant 90 4 times as loud Garbage Disposal (3 ft) Noisy Urban Daytime 80 2 times as loud Passenger Car, 65 mph (25 ft) Living Room Stereo (15 ft) Vacuum Cleaner (10 ft) Commercial Areas 70 Reference Loudness Moderately Loud Normal Speech (5 ft) Air Conditioning Unit (100 ft) Data Processing Center Department Store 60 1/2 as loud Light Traffic (100 ft) Large Business Office Quiet Urban Daytime 50 1/4 as loud Bird Calls (distant) Quiet Urban Nighttime 40 1/8 as loud Quiet Soft Whisper (5 ft) Library and Bedroom at Night Quiet Rural Nighttime 30 1/16 as loud Broadcast and Recording Studio 20 1/32 as loud Just Audible 0 1/64 as loud Threshold of Hearing Source: Compiled by dBF Associates, Inc., 2016 @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 7 City of Carlsbad 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 Tyler Street. Motor vehicle can be a concern when it is characterized by a high number of individual events that can create a sustained noise level in proximity to noise sensitive uses. Interstate 5 is located approximately 1,900 feet to the east. It was not audible as background noise and at the time the site visit occurred and likely 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 250 feet west 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 wheel-rail noise and engine noise is audible at the project site. The warning horns/bells that are used when trains are approaching or departing the Carlsbad Village Drive station are audible; thus, train noise contributes to the ambient noise environment in the study area. McClellan- Palomar Airport is located approximately 4.0 miles southeast of the site. The site is outside the airport influence area; however, aircraft operations (airplanes and helicopters) are 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). This provides a graphic illustration of sound levels near road corridors, but typically does not include effects of landforms and adjacent structures. 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. Under existing conditions as shown in Noise Element Figure 5-2, the project site is within the 60-65 dBA CNEL contour intervals for the railroad track and outside the noise contours for I-5. As shown in Noise Element Figure 5-3, the project site would remain within the 60-65 dBA railroad contour at build out which is anticipated to occur in 2040. The dominant noise source at the project site is traffic on surface streets and Interstate 5. To gather data on the general noise environment at the project site, one weekday 15-minute noise measurement were acquired in proximity to the project site on Wednesday, January 31, 2024, using an ANSI Type II integrating sound level meter. The predominant noise source in the area during monitoring was traffic on Tyler Street. Aircraft overflights and train pass by events @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 8 City of Carlsbad occurred which contribute to ambient conditions. During monitoring, a total of 17 cars/light trucks passed the monitoring site on Tyler Street. Table 2 identifies the noise measurement location and measured noise levels. The monitoring location is shown in Figure 3. Monitoring data is provided as Appendix A. Table 2 Noise Monitoring Results Measurement Location Primary Noise Source Sample Time Leq (dBA) Southeast corner of the Project site located on Tyler Street. Traffic Weekday afternoon 60.1 Source: Field visit using ANSI Type II Integrating sound level meter. Regulatory Setting 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 Table 2 of General Plan Noise Element (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. Interior spaces within commercial buildings are limited to 50 dBA CNEL. 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 traffic at neighboring receivers. An interior noise standard of 45 dBA CNEL is used herein as referenced in the City of Carlsbad Noise Guidelines Manual (1995). Each unit would have internal heating, ventilation and air conditioning (HVAC) units rather than exterior roof-mounted units. Noise from stationary HVAC units would not be audible outside the residential units. @O© BIRDSEYE PLANNING GROUP I I Figure 3—Monitoring LocaƟon - Monitoring LocaƟon • 3215-3225 Tyler Street Residential Project Noise Study 10 City of Carlsbad 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 peak particle velocity (PPV) in inches per second and is referenced as vibration decibels (VdB) for the purpose of evaluating the potential for adverse construction-related impacts. The vibration velocity level threshold of perception for humans is a PPV of approximately 0.01 inches/second which equates to 65 VdB. A vibration velocity of 75 VdB is the approximate dividing line between barely perceptible and distinctly perceptible levels. With respect to potential ground-borne vibration impacts on structures, the FTA states that ground-borne vibration levels in excess of PPV 0.2 inches/second (100 VdB) could damage fragile buildings and levels in excess of PPV 0.12 inches/second (95 VdB) could damage extremely fragile historic buildings. No historic buildings occur on the site or are known to occur near the site. Adjacent buildings are all relatively modern structures constructed consistent with applicable California Building Code and seismic standards. However, to conservatively estimate potential vibration impacts on neighboring residences, a PPV of 0.2 inches per second (100 VdB) is used. 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 developed with two single-family residences. Noise levels associated with existing and future traffic were based on the difference in trip volumes between existing volumes counted during monitoring and the proposed use less traffic generated by the existing 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. Rail noise levels at the site were estimated based on methodologies approved by the Federal Rail Administration to determine whether interior noise levels would be met at the closest residences. 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 @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 11 City of Carlsbad 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. The existing measured Leq noise level is 60.1 dBA which as stated, includes aircraft overflight and train pass by events. Thus, measured baseline noise levels equal the 60 dBA standard. The determination of impact is based on whether existing exterior noise levels would noticeably change existing conditions (i.e., +/- 3 dBA) with project operation. 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 3 shows typical noise levels associated with heavy construction equipment. As shown, average noise levels associated with the use of heavy equipment at construction sites can range from 75 to 88 dBA at 50 feet from the source, depending upon the types of equipment in operation at any given time and phase of construction. Table 3 Typical Maximum Construction Equipment Noise Levels Equipment Onsite Typical Maximum Level (dBA) 25 Feet from the Source Typical Maximum Level (dBA) 50 Feet from the Source Typical Maximum Level (dBA) 100 Feet from the Source Air Compressor 86 80 74 Backhoe 86 80 74 Bobcat Tractor 86 80 74 Concrete Mixer 91 85 79 Loader 86 80 74 Bulldozer 91 85 79 Jack Hammer 94 88 82 Pavement Roller 91 85 79 Street Sweeper 88 82 76 Man Lift 81 75 69 Dump Truck 90 84 78 Mobile Crane 89 83 77 Excavator/Scraper 91 85 79 Source: FTA Noise and Vibration Impact Assessment Manual (September 2018), Table 7-1. Noise levels are based on actual maximum measured noise levels at 50 feet (Lmax). Noise levels are based on a noise attenuation rate of 6 dBA per doubling of distance. As noted, the closest residential properties are approximately 50 feet to the east across Tyler Street and construction noise will be audible at these properties. Table 4 shows typical @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 12 City of Carlsbad 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 noise level used to estimate the maximum noise level that could occur is based on use of a bobcat 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 78 dBA 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. Table 4 Typical Maximum Construction Noise Levels at Various Distances from Project Construction Distance from Construction Maximum Noise Level at Receptor (dBA) 25 feet 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 78 dBA. However, temporary construction 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. Construction Noise Reduction Measures Temporary construction noise impacts could be reduced through implementation of measures N-1 through N-3. These are not mitigation measures but can be implemented at the applicant’s discretion to reduce construction-related noise. N-1 Construction Equipment. Electrical power scan 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 @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 13 City of Carlsbad 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. N-2 Limit Operations Adjacent to Receivers. Limit the number of large pieces of equipment (i.e., backhoes or concrete mixers) operating proximal or adjacent to receivers at any time. N-3 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 construction noise and be easily viewed from adjacent public areas. Residual Impacts Project construction would represent a temporary source of noise at the project site. Measures N-1 through N-3 could reduce construction noise levels at neighboring properties. No residual impacts associated with construction noise are anticipated. Temporary Construction-Related Vibration Activities associated with residential projects do not generate vibration. Thus, this discussion will focus on temporary vibration caused by construction. As referenced, the closest residences to the site are approximately 50 feet east of the site. Additional residences are located to the north and south of the site on the east side of Tyler Street. Based on the information presented in Table 5, vibration levels from operation of a large bulldozer would conservatively be 87 VdB (0.089 inches/second) or less at 50 feet (Caltrans 2013). Grading within 50 feet of the nearest residential structures would be required. As discussed, a PPV of 0.2 inches/second (100 VdB) is the vibration energy required to damage fragile historic buildings. While vibration from grading may be perceived at neighboring residences, the vibration energy would be well below that required to cause structural damage. There are no residential buildings adjacent to and north/south of the project site. Maximum vibration levels would range from 58 to 87 VdB depending on the type of equipment used. Vibration would not adversely affect the commercial buildings; however, provided construction @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 14 City of Carlsbad occurs within the prescribed hours, temporary impacts would not be considered adverse. Impacts would be less than significant. Table 5 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. Whether a traffic-related noise impact would occur is based on whether the project would double peak hour traffic volumes relative to existing conditions; thus, causing a noticeable (i.e., 3 dBA or greater) increase in noise levels. 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. According to the City of San Diego Trip Generation Manual, the existing single-family residences generate approximately 9 trips per unit daily or a total of 18 trips. The proposed project would construct a total of 12 units on the site or an increase of ten units. Using the same trip generation rate, the project could generate up to 90 new daily trips when existing trips are subtracted from the total. Of the total, approximately 10% (or 9 trips) would occur during the peak hour. The remainder would occur throughout the day. Noise levels generated by traffic on Tyler Street was modeled using the Federal Highway Administration Traffic Noise Model (TNM) version 2.5 software (see Appendix A). The model calculates traffic noise at receiver locations based on traffic volumes, travel speed, mix of vehicle types operating on the roadways (i.e., cars/trucks, medium trucks and heavy trucks) and related factors. Traffic volumes and vehicle mix used to calibrate TNM were based on vehicle counts obtained during the monitoring period. The 15-minute counts were multiplied by four to obtain hourly traffic counts. Traffic on Tyler Street is light in comparison more heavily traveled streets in the Carlsbad Village area and train noise does affect baseline conditions in the project area. The model was calibrated to approximate baseline measurements when considering non-traffic related noise sources. Noise levels were calculated at the following receivers and are intended to represent conditions at multiple receivers within proximity to these locations: @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 15 City of Carlsbad 1. Single-family residences art 3250 Tyler Street located east of the site on the east side of Tyler Street. 2. Multi-family residence located at 507 and 515 Pine Street across the street and east of the project site; and 3. Project residences. The receiver locations are shown in Figure 4. As shown in Table 6, project traffic would add approximately 0.7 dBA to the baseline traffic conditions. Noise levels at the receivers along Tyler Street would be less than the 60-dBA standard. The addition of 6 peak hour trips to baseline traffic volumes would increase noise levels but have no noticeable effect (i.e., +/- 3 dBA) on noise levels at the modeled receivers. Table 6 Modeled Noise Levels Receptor Existing Leq Exceed Standard? With Project Leq dBA Change Significant Impact Site 1 52.8 No 53.5 +0.7 No Site 2 51.1 No 51.8 +0.7 No Site 3 54.5 No 55.2 +0.7 No Thus, long term traffic operation associated with the project would have no 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. Current development is 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). Older residences typically provide a 20-25 dBA reduction in exterior noise levels. When windows are open, the insertion loss drops to about 10 dBA. Assuming windows are closed and an insertion loss of 25 dBA, interior noise levels at modeled receivers would be reduced to between 23.7 dBA and 30.2 dBA which would be below the 45-dBA interior standard for residences. Exterior Railroad Noise. The AT&SF corridor is located approximately 250 feet west 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 50 trains 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 are used. The existing rail noise levels at the project site were calculated using a proprietary @O© BIRDSEYE PLANNING GROUP Figure 4—Receiver LocaƟons - Receiver LocaƟons • 3215-3225 Tyler Street Residential Project Noise Study 17 City of Carlsbad software program based on Federal Rail Administration methodology. Because Coaster trains stop at the Carlsbad station (Amtrak and freight trains do not), it was assumed the average speed through the area is 35 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 were audible during monitoring; thus, it was assumed that train operators do use the warning horn when in proximity to the site. Of the 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 250 feet west of the rail corridor) is approximately 65.2 dBA when both passenger and freight rail operations are combined. The estimated CNEL is consistent with CNEL contours provided in the 2015 General Plan Update Noise Element for residential areas within the City of Carlsbad. Thus, existing exterior noise levels associated with rail operation exceed the recommended CNEL (60-dBA) for residential uses. Interior Railroad Noise. As stated, the existing exterior CNEL at the site exceeds the standard recommended by the City of Carlsbad for residential uses. 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, assuming an exterior baseline of 65.2 dBA, would be 35.2 dBA and well below background noise levels. No measures in addition to compliance with Title 24 design requirements would be necessary to reduce interior rail noise to below the residential standard. Exterior Outdoor Space. The City of Carlsbad Noise Guidelines Manual states that noise levels within outdoor open space areas should not exceed 60 dBA CNEL. For the proposed project, all outdoor open space requirements, with the exception of Units 5 and 11, would be met within the ground floor private yard areas provided for each unit. Outdoor common areas would be provided between buildings A and C and between buildings B and D. As stated, ambient noise levels along Tyler Street, including the project site, are dominated by traffic on Tyler Street. As shown in Table 6, traffic noise would be below the 60 dBA criteria for outdoor open space as specified in the Carlsbad Noise Guidelines Manual; thus, no project design features would be required to reduce traffic noise within the outdoor open space areas. With respect to train noise, as discussed above, noise levels at the western property line would be approximately 65.2 dBA CNEL. Construction of the six-foot high vinal privacy fence along the western property boundary would reduce noise levels by approximately 8 dBA provided mass loaded, gap free panels are used and there are no gaps under the fence or at the tie in points with the buildings or fence sections along the north and south sides of the site. With respect to the second-floor balconies constructed as part of Unit 5 and 11, the outdoor open space will be screened by Units 6 and 12 to the west which would provide approximately 10 dBA of attenuation. This would reduce outdoor open space noise to approximately 55 dBA CNEL. No project design features would be required to meet the 60 dBA standard. As stated, @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 18 City of Carlsbad the outdoor common space would be located near the center of the site between the townhome buildings. The buildings and distance from the railroad tracks would provide adequate screening/attenuation such that the outdoor open space standard would be met at these locations. Rail Vibration. As noted, the proposed project would be constructed approximately 250 feet east 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 residents. Because the project is a residential development, it would be considered a Category 2 land use for the purposes of vibration assessment as defined in the Federal 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 corridors where train vibration events occur occasionally (i.e., 30 to 70 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 use 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. 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 Assessment Manual), the vibration level is 72 VdB at approximately 250 feet from the track at a reference speed of 50 miles per hour. Using a correction factor of 3 VdB for speed (35 mph in the study area vs. a 50 mph reference level), the vibration level at the site is estimated at 69 VdB. This is likely conservative given the amount of ballast rock in the track bed; however, for the purpose of assessing potential vibration levels, projected vibration levels would not exceed the 72 VdB threshold. Airport Noise. McClellen-Palomar Airport is the nearest airport and is located approximately 4.0 miles southeast of the project site. Based on the noise contour maps provided in the McClellen-Palomar Airport Land Use Compatibility Plan, Exhibit III-1, the project site is located outside the 60 dB CNEL contour and is not affected by airport noise (McClellen-Palomar @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 19 City of Carlsbad Airport Land Use Compatibility Plan (adopted January 25, 2010). For this reason, the project site is not located in an area affected by aircraft noise; and thus, compatibility with an adopted Airport Land Use Compatibility Plan is not required. Conclusion The proposed project was evaluated for potential construction and operational noise impacts in accordance with the City of Carlsbad guidelines and applicable CEQA significance thresholds. As discussed herein, project related noise impacts would be less than significant. Would the project result in the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? 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. Temporary construction noise is not restricted if it occurs between the hours specified in the noise ordinance as referenced herein. With installation of balcony partition barriers, exterior open space noise levels would meet City standards at all units. Operational impacts related to exterior and interior traffic noise would be less than significant. With installation of a vinal privacy fence along the western site boundary, rail noise would be reduced to below 60 dBA CNEL. Thus, the outdoor open space standard would be met. The project would not result in the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies. Would the project result in the generation of excessive groundborne vibration or groundborne noise levels? As stated herein, temporary impacts associated with construction vibration would be less than significant. The proposed project is a 12-unit, three-story residential development. This use does not generate vibration; thus, no vibration impacts are anticipated to occur with operation of the project. For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? McClellen-Palomar Airport is the nearest airport and is located approximately 4.4 miles southeast of the project site. Based on the noise contour maps provided in the McClellen- Palomar Airport Land Use Compatibility Plan, Exhibit III-1, the project site is located outside @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 20 City of Carlsbad the 60 dB CNEL contour and is not affected by airport noise (McClellen-Palomar Airport Land Use Compatibility Plan (adopted January 25, 2010). For this reason, the project site is not located in an area affected by aircraft noise; and thus, compatibility with an adopted Airport Land Use Compatibility Plan is not required. @O© BIRDSEYE PLANNING GROUP 3215-3225 Tyler Street Residential Project Noise Study 21 City of Carlsbad References City of Carlsbad. General Plan Update Noise Element. 2015. City of Carlsbad. Noise Guidelines Manual. September 1995. City of San Diego. San Diego Trip Generation Manual, Land Development Code, May 2003. 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 Manual. September 2018. Federal Rail Administration (FRA) Guidelines (Report Number 293630-1), December 1998. Institute of Transportation Engineers (ITE) publication Trip Generation, 11th Edition Lee and Associates, Inc., McClellen-Palomar Airport Land Use Compatibility Plan (adopted January 25, 2010). @O© BIRDSEYE PLANNING GROUP Appendix A Appendix A Monitoring Data Sheet @O© BIRDSEYE PLANNING GROUP 3215 Tyler Street Start Date 1/31/2024 Start Time 4:35:09 PM End Time 4:50:08 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 71.1 LCeq 70.3 LAeq 60.1 LZSmax 92.6 LCSmax 92.3 LASmax 82.4 LZSmin 59.4 LCSmin 56.8 LASmin 42.1 LZE 100.6 LCE 99.8 LAE 89.6 LZpk 104.5 LCpk 104.4 LApk 95.8 LAS1% 72.0 LAS2% 68.5 LAS5% 63.1 LAS8% 61.4 LAS10% 60.4 LAS25% 54.6 LAS50% 49.7 LAS90% 46.0 LAS95%44.1 LAS99% 43.0 RESULTS: SOUND LEVELS <Project Name?> <Organization?> 7 February 2024 <Analysis By?> TNM 2.5 Calculated with TNM 2.5 RESULTS: SOUND LEVELS PROJECT/CONTRACT: <Project Name?> RUN: Tyler Street Existing BARRIER DESIGN: INPUT HEIGHTS Average pavement type shall be used unless a State highway agency substantiates the use ATMOSPHERICS: 68 deg F, 50% RH of a different type with approval of FHWA. Receiver Name No.#DUs Existing No Barrier With Barrier LAeq1h LAeq1h Increase over existing Type Calculated Noise Reduction Calculated Crit'n Calculated Crit'n Impact LAeq1h Calculated Goal Calculated Sub'l Inc minus Goal dBA dBA dBA dB dB dBA dB dB dB Receiver1 1 1 0.0 52.8 66 52.8 10 ----52.8 0.0 8 -8.0 Receiver2 2 1 0.0 51.1 66 51.1 10 ----51.1 0.0 8 -8.0 Receiver3 3 1 0.0 54.5 66 54.5 10 ----54.5 0.0 8 -8.0 Dwelling Units # DUs Noise Reduction Min Avg Max dB dB dB All Selected 3 0.0 0.0 0.0 All Impacted 0 0.0 0.0 0.0 All that meet NR Goal 0 0.0 0.0 0.0 C:\TNM25\Program\3215 Tyler Street 1 7 February 2024 I I RESULTS: SOUND LEVELS <Project Name?> <Organization?> 7 February 2024 <Analysis By?> TNM 2.5 Calculated with TNM 2.5 RESULTS: SOUND LEVELS PROJECT/CONTRACT: <Project Name?> RUN: Tyler Street With Project BARRIER DESIGN: INPUT HEIGHTS Average pavement type shall be used unless a State highway agency substantiates the use ATMOSPHERICS: 68 deg F, 50% RH of a different type with approval of FHWA. Receiver Name No.#DUs Existing No Barrier With Barrier LAeq1h LAeq1h Increase over existing Type Calculated Noise Reduction Calculated Crit'n Calculated Crit'n Impact LAeq1h Calculated Goal Calculated Sub'l Inc minus Goal dBA dBA dBA dB dB dBA dB dB dB Receiver1 1 1 0.0 53.5 66 53.5 10 ----53.5 0.0 8 -8.0 Receiver2 2 1 0.0 51.8 66 51.8 10 ----51.8 0.0 8 -8.0 Receiver3 3 1 0.0 55.2 66 55.2 10 ----55.2 0.0 8 -8.0 Dwelling Units # DUs Noise Reduction Min Avg Max dB dB dB All Selected 3 0.0 0.0 0.0 All Impacted 0 0.0 0.0 0.0 All that meet NR Goal 0 0.0 0.0 0.0 C:\TNM25\PROGRAM\3215 TYLER STREET\3215 Tyler Street With Project 1 I I