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CT 2018-0008; GRAND JEFFERSON; NOISE STUDY; 2018-09-01
GRAND JEFFERSON MIXED USE PROJECT NOISE STUDY Prepared for: Rincon Real Estate Group Prepared by: 0 © BIRDSEYE PLANNING GROUP September 2018 Grand Jefferson Mixed Use Project Noise Study 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 ................................................................................... 13 Residual Impacts ............................................................................................................................ 13 Temporary Construction-Related Vibration .............................................................................. 14 Long-Term Operational Noise Exposure .................................................................................... 14 References ................................................................................................................................................. 19 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 0&0 BIRDSEYE PLANNING GROUP City of Carlsbad The Grand Jefferson Mixed-Use Project Noise Study GRAND JEFFERSON MIXED USE PROJECT CARLSBAD, CALIFORNIA NOISE STUDY This report is an analysis of the potential noise impacts associated with the Grand Jefferson Mixed Use project, a 6-unit condominium development proposed for construction 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 is located at 786 Grand A venue at the northwest corner of Grand A venue and Jefferson Street. The project would replace an existing single-family residential structure with a 6-unit mixed use condominium building. The building would be four stories in height with 2,331 square foot commercial/lobby area and covered parking on the first floor and two condominium units on the upper three floors. Each floor would be approximately 4,975 square feet. The parking/garage area would be 4,108 square feet and prove a total of 14 parking spaces. Construction would require the demolition and removal of the existing residential building which was most recently used as a daycare facility. Construction is anticipated to begin in mid- 2019 by early 2020. 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 0~© BIRDSEYE PLANNING GROUP 2 City of Calrsbad Figure 1-Project Site .I.Bill NOSH1/E{ ,, V) 'CJV9mv:) £ i 3/1N1'W ONYll:'.> 9\lL , I at,1.1a111■,llltliJ ~ i, 1 .l. I I I 1 I ! I } i ! I I I I I !" ;. ~4~ r ~ ~ :c:: ~ I::: v'i ..... :§ '-S:; ~'! 8 i C ro 0.. QJ ..... l/') I N QJ ~ :::::, tl.O LL The Grand Jefferson Mixed-Use Project Noise Study 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 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 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 the project site. Once constructed, the residential element of the project will be a sensitive receptor. Commercial and multifamily residences are the dominant land use in the area. 0G>© BIRDSEYE PLANNING GROUP 5 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study Table 1. Sound Levels of Typical Noise Sources and Noise Environments Human Judgment of Noise Source A-Weighted Noise Loudness {at Given Noise Environment Sound Level {Relative to Reference Distance) {Decibels) Loudness of 70 Decibels*) Military Jet Takeoff with Afterburner Carrier Flight Deck 140 128 times as loud (50 ft) Civil Defense Siren (100 ft) 130 64 times as loud Commercial Jet Take-off (200 32 times as loud ft) 120 Threshold of Pain Rock Music Concert Inside Pile Driver (50 ft) Subway Station (New York) 110 16 times as loud Ambulance Siren (100 ft) Newspaper Press (5 ft) 100 8 times as loud Gas Lawn Mower (3 ft) Very Loud Food Blender (3 ft) Boiler Room Propeller Plane Flyover (1,000 Printing Press 90 4 times as loud ft) Diesel Truck (150 ft) Plant Garbage Disposal (3 ft) Noisy Urban Daytime 80 2 times as loud Passenger Car, 65 mph (25 ft) Living Room Stereo ( 15 ft) Commercial Areas 70 Reference Loudness Vacuum Cleaner (10 ft) Moderately Loud Normal Speech (5 ft) Data Processing Center Air Conditioning Unit Department Store 60 1/2 as loud (100 ft) Light Traffic (100 ft) Large Business Office 50 1/4 as loud Quiet Urban Daytime 1/8 as loud Bird Calls (distant) Quiet Urban Nighttime 40 Quiet Soft Whisper (5 ft) Library and Bedroom at 30 1/16 as loud Night Quiet Rural Nighttime Broadcast and Recording 1/32 as loud Studio 20 Just Audible 1/64 as loud 0 Threshold of Hearing Source: Compiled by dBF Associates, Inc., 2016 041>© 6 City of Calrsbad BIRDSEYE PLANNING GROUP The Grand Jefferson Mixed-Use Project 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 Grand Avenue and Jefferson 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 1,200 feet to the east. It is audible as background noise and contributes to overall noise levels at the project site. The Atichson, Topeka and Santa Fe Railroad (AT&SF) rail corridor is located approximately 1,300 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 wheel-rail noise and engine noise is not 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 does contribute 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. The project site is outside the 60-65 dBA CNEL contour intervals for both the railroad track and I-5. To gather data on the general noise environment at the project site, two weekday 15-minute noise measurement were acquired in proximity to the project site on Thursday, August 30, 2018, using an ANSI Type II integrating sound level meter. The predominant noise source in the area during monitoring was traffic on Grand Avenue and Jefferson Street. Aircraft overflights and train pass by events contributed to ambient conditions. 0e@ I 7 City of Calrsbad BIRDSEYE PLANNING GROUP The Grand Jefferson Mixed-Use Project Noise Study During monitoring, a total of 141 cars/light trucks, 2 medium (two-axle 6-wheel) trucks and 2 heavy (18-wheel trucks) trucks passed the Jefferson Avenue monitoring site. A total of 145 cars/light trucks passed the Grand Avenue monitoring site. Table 2 identifies the noise measurement location and measured noise levels. The monitoring location is shown in Figure 3. Noise levels are noticeably louder at Site 1. Based on field observations, this can be partially explained by the volume of accelerating traffic traveling north on Jefferson Avenue from the stop light at the intersection with Grand A venue. This volume is greater than the volume of traffic accelerating westbound on Grand A venue from the same intersection. Monitoring data is provided as Appendix A. Table 2 Noise Monitoring Results Measurement Location Primary Noise Sample Time Leq (dBA) Source Project site located on Jefferson Street Traffic Weekday afternoon 63.5 Project site located on Grand Avenue Traffic Weekday morning 60.6 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 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. 0~@ BIRDSEYE Plf,NNlNG GROUP 8 City of Calrsbad Figure 3-Monitoring Locations The Grand Jefferson Mixed-Use Project Noise Study 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). 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 (V dB) 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 V dB. A vibration velocity of 75 V dB 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 V dB) 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 structure 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 V dB) is used herein. 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 a single-family residence most recently used as a daycare facility. The building appeared vacant at the time this study was prepared. Noise levels associated with existing and future traffic were based on the difference in trip volumes between the existing volumes 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 1,300 feet O)~@ BIRDSEYE PLANNING GROUP 10 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study west 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 currently exceed 60 dBA as referenced above; thus, the determination of impact is based on whether existing noise levels would noticeably increase (+3 dBA) as a result of project operation. All mechanical equipment associated with the project would be located within roof top enclosures or in the building mechanical area. Mechanical noise is not expected to be audible 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 3 demonstrates the 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 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). T Equipment Onsite Air Compressor Backhoe Bobcat Tractor Concrete Mixer Bulldozer Jack Hammer Pavement Roller Street Sweeper Man Lift C)t1)@ BIRDSEYE PLANNING GROUP yp1ca IC ons rue ,on :Qu1pmen Table 3 t f E t N . L 0158 Typical Level Typical Level (dBA) (dBA) 25 Feet 50 Feet from the from the Source Source 84 78 84 78 84 78 85 79 88 82 95 89 86 80 88 82 81 75 11 eves Typical Level (dBA) 100 Feet from the Source 64 64 64 73 76 83 74 76 69 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study T yp1ca IC ons rue 10n :qu1pmen Table 3 t f E t N . L 0158 eves Typical Level Typical Level (dBA) Typical Level (dBA) Equipment Onsite (dBA) 25 Feet 50 Feet from the 100 Feet from the from the Source Source Source Dump Truck 82 76 70 Source: Noise levels based on FHWA Roadway Construction Noise Model (2006) Users Guide Table 1. Noise levels based on actual maximum measured noise levels at 50 feet (Lmax). Noise levels assume a noise attenuation rate of 6 dBA per doubling of distance. As noted, there are residential properties adjacent to the site and construction noise will be audible at these properties. Table 4 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 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 84 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 Maximum Noise Level at Construction 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 84 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. me@ BIRDSEYE PLANMNG GROUP 12 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study Construction Noise Reduction Measures Temporary construction noise impacts could be reduced through implementation of measures N-1 through N-4. These are not mitigation measures but can be implemented at the applicant's discretion to reduce construction-related noise. 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 construction 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-4 could reduce construction noise levels at neighboring properties. No residual impacts associated with construction noise are anticipated. 0~0 BIRDSEYE PLANNING GROUP 13 City of Calrsbad The Grand Jefferson Mixed-Use Project 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. As referenced, the closest residences to the site are located adjacent to and both west and north. Based on the information presented in Table 5, vibration levels from operation of a large bulldozer would be approximately 87 VdB (0.089 inches/second) or less at 25 feet (Caltrans 2013). Grading within 25 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. Vibration levels at residential buildings adjacent to the project site may exceed the groundbome velocity threshold level of 72 VdB for residences and/or buildings where people sleep as discussed above. Maximum vibration levels would range from 58 to 87 V dB depending on the type of equipment used. However, as long as construction occurs within the prescribed hours, any temporary impact would be considered adverse, but 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. 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. As referenced, the existing structure is a daycare facility which generates approximately 80 trips per 1,000 square feet (City of San Diego Trip Generation Manual, May 2003). The structure is approximately 2,124 square feet; and thus, when it was in operation, it could have generated up to approximately 170 weekday trips. 0e© BIRDSEYE PLANNlNG GROUP 14 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study 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, 8th Edition for condominiums/apartments and retail. Peak hour trips are assumed to be 10% of the ADT. For the purpose of this analysis, the residential uses would generate 0.62 peak hour trips per unit or 4 hourly trips. The retail use (2,191 square feet) would generate 6.82 peak hour trips per 1,000 square feet (15 trips). The proposed project would generate 19 peak hour trips which is less than the existing use. Noise levels generated by traffic on Jefferson Street and Grand Avenue 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. The model was calibrated to calculate noise levels that are+/-2 dBA those measured on-site and reported in Table 2. Noise levels were calculated at the following receivers and are intended to represent conditions at multiple receivers within proximity to these locations: 1. Single-family residence located adjacent to and north of the site; 2. Project site at 786 Grand A venue; and 3. Jefferson House II Apartments located northeast of the project site and across Jefferson Street from Receiver 1. The receiver locations are shown in Figure 4. As shown in Table 6, the daytime hourly average (Leq) exceeds the 60-dBA standard at the receivers modeled under baseline conditions. The addition of 19 peak hour trips to baseline traffic volumes would have no noticeable effect on noise levels at the three receivers modeled. Receptor Existing Leq Site 1 64.2 Site 2 62.9 Site 3 62.5 Table 6 Modeled Noise Levels Exceed With Project Standard? Lea Yes 64.2 Yes 63.0 Yes 62.6 dBAChange Significant Impact +0.0 No +0.1 No +0.1 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. 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 0~© BIRDSEYE PLANNING GROUP 15 City of Calrsbad Figure 4-Sensitive Receivers The Grand Jefferson Mixed-Use Project Noise Study (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 63.5 (baseline) to 33.5 dBA which would be below the 45-dBA standard. Exterior Railroad Noise. The AT&SF corridor is located approximately 1,300 feet to the 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 time tables, 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 software program based on Federal Rail Administration methodology. Because Coaster trains stop at the Carlsbad station (Amtrak and freight trains do not), which is located approximately 1,300 feet west of the site, it was assumed the average speed through the area is 35 miles per hour. 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 1,300 feet west of the rail corridor) is approximately 48 dBA when both passenger and freight rail operations are combined. The estimated CNEL is less than measured background noise and generally appears consistent with CNEL contours provided in the 2015 General Plan Update Noise Element for residential areas within the City of Carlsbad. Rail operation would not exceed the recommended CNEL (60- dBA) for residential uses. Interior Railroad Noise. The existing exterior CNEL at the site does not exceed the standard recommended by the City of Carlsbad for residential uses. Design features associated with the project would 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 48 dBA CNEL to 18 dBA CNEL which would be well below background noise levels. No measures in addition to compliance with Title 24 design requirements would be necessary to reduce interior rail noise. Rail Vibration. As noted, the proposed project would be constructed approximately 1,300 feet west of the rail corridor. Thus, a screening evaluation of potential vibration impacts O)~@ BIRDSEYE PLANNING GROUP 17 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study 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 (2006). 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 V dB 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 9.2 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 10 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 10-1 in the Federal Transit Administration, Transit Noise and Vibration Impact Assessment Manual), the vibration level is 67.0 VdB at approximately 300 feet from the track at a reference speed of 50 miles per hour. This is likely conservative given the amount of ballast rock in the track bed and soil propagation; however, vibration from rail operation would not be perceptible at a distance of 1,300 feet from the source. The 72 VdB threshold would not be exceeded at the project site. 0~0 BIRDSEYE PLANNING GROUP 18 City of Calrsbad The Grand Jefferson Mixed-Use Project Noise Study 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. May 2006. 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 Assessment. Federal Transit Administration, Office of Planning and Environment. http://www.fta.dot.gov/documents/FTA Noise and Vibration Manual.pd£ Harris Miller Miller & Hanson Inc. Transit Noise and Vibration Impact Assessment, Final Report. May 2006. Institute of Transportation Engineers (ITE) publication Trip Generation, 8th Edition 06>© BIRDSEYE PLANNING GROUP 19 City of Calrsbad 0@© BIRDSEYE PLANNING GROUP Appendix A Monitoring Data Sheet Appendix A . ID FIELD NOISE f\tlEASUREMENT DATA. Roadway Na1:1e ~~~ Speed (post/obs) 2:~ Number of Lanes 2,. VVidth (pave/rowY.,J< 1-or 2-way'L .. Grade o/ Bus Stops ?CJ Si:oplights o/-5' Street Parkingql,J' Automobiles~/✓tl Medium Trucks 7 Heavy TrucksZ- .. .. #. I r:.:,r;;~ ~ ·-._7~ C.-,•-· --;, -~./ ·3u., Page ----l of ocation(s) / GPS Readin_p(s): Ofuer t..b?se ~ rustam~~ trams: sooscaping J rus3ing Jea>.res t chidren ~.! qs~ ! ~ ~ Noresaruii~oo~ j __ Jefferson Avenue Site Start Date 8/30/2018 Start Time 3:19:27 PM End Time 3:34:26 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 77.6 LCeq 76.3 LAeq 63.5 LZSmax 94.8 LCSmax 94.3 LASmax 81.2 LZSmin 65.6 LCSmin 63.3 LASmin 48.5 LZE 107.1 LCE 105.8 LAE 93.0 LZpeak 105.2 LCpeak 104.3 LApeak 95.7 1% 74.S 2% 71.4 5% 68.0 8% 66.S 10% 65.8 25% 63.0 50% 60.2 90% 53.9 95% 52.1 99% 49.9 Site 1 Page 1 Grand Avenue Site Start Date 8/30/2018 Start Time 3:42:54 PM End Time 3:57:54 PM Duration 00:15:00 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 75.3 LCeq 73.2 LAeq 60.6 LZSmax 91.7 LCSmax 91.2 LASmax 82.0 LZSmin 65.9 LCSmin 63.3 LASmin 47.7 LZE 104.8 LCE 102.7 LAE 90.1 LZpeak 103.4 LCpeak 102.9 LApeak 95.5 1% 67.7 2% 66.0 5% 64.2 8% 62.9 10% 62.4 25% 59.6 50% 55.9 90% 50.9 95% 50.0 99% 48.5 Site 2 Page 1 RESULTS: SOUND LEVELS <Organization?> <Analysis By?> RESULTS: SOUND LEVELS PROJECT/CONTRACT: RUN: BARRIER DESIGN: ATMOSPHERICS: ---.··~---·--•~,""' ·--~---·------"-----·---· . ·--·---·· Receiver .......................... <Project Name?> Existing Conditions INPUT HEIGHTS 68 deg F, 50% RH ---·-•·-•--·-··-···--·-····· Name ---------------_ -~----------------------------------------------_----------:No. :#DUs Existing No Barrier i ; LAeq1h l.Aeq1h.. --- -I Calculated :Crit·n I , , i I <Project Name?> 3 September 2018 TNM 2.5 Calculated with TNM 2.5 Average pavement type shall be used unless a State highway agency substantiates the use of a different type with approval of FHWA. !With Barrier ~ ....•. -..·----······---------- Increase over existing --Tfype -'catculateci" N-o-is_e_R_e_d_u_c-tio-n----~- Calculated [Crit'n ---~Impact :LAeq1h Calculated ,Goal 1Calculated Sub'I Inc -)minus ---·-----·----------·------------i----.--------1 ..... j ...... --· ---···············l--···· ... ·.··· ............... \ .... . dBA ___ _l_dBA idBA !dB Goal ,dBA dB !dB ldB dB Receiver1 : 1] O.O! 64.21 66! 64.2 661 62.9 Receiver2 _ ______ ---------------------_-_----------, -il____ ·1: .. -- Receiver3 Dwelling Units 3j 1i ~:~I :~::I 66' • -62.5 # DUs ! Noise Reduction dB [~~---------------;;: ~: ::.s.~R:~, .. -:: ' . . t~~tij iil--o-_ .!!.--ii 0.0 0.0 C:\TNM25\Program\Grand Jefferson 1 10· 10 10 64.2 -----: ·············,···································.J 0.0t Bi -8.0 ' -r ------0.0, 8: -8.0 62.9 ----,------o.o! 8l -s.o -------------------------- 3 September 2018 RESULTS: SOUND LEVELS <Organization?> <Analysis By?> RESULTS: SOUND LEVELS PROJECT/CONTRACT: RUN: BARRIER DESIGN: ATMOSPHERICS: Receiver Name I· <Project Name?> <Project Name?> With Project INPUT HEIGHTS ... 58deg F, 50% RH____________ ---·----···-· ... ______ _ ===== 3 September 2018 TNM2.5 Calculated with TNM 2.5 Average pavement type shall be used unless a State highway agency substantiates the use . ··---~fl:'~i!!!!:ent type with approv._~l?!F~~~'.-_ -------···-·---·-····--No. 1#OUs Existing No Barrier LAeq1h LAeq1h Calculated ,crit'n \Increase over existing ·· !Type t-::----c : \Calculated Crit'n :impact Sub'! Inc !With Barrier Calculated Noise Reduction LAeq1 h Calculated Goal J ···············'························+·······················+··············· 3Ads ds ; ··················· :J~~ · ·-··las dBA ............ J~~~ ,di dB Calculated minus !Goal dB Kece1ver1 I 1 11 0.01 64.2' ·-··-·-··-' ·----· --t ----~ -· 66: 64.2 10 8 -8.0 Receiver2 Receiver3 2i ~I 0.01 -i------+------f--------+ ·····----+-·······---····-~.---------------1 63.0i 0.0 63.0i 66i 63.0 10 8 -8.0 .... 1. ························ 3! 0.0 62.6! 66\ 62.6 10 62.6! 0.0 8 -8.0 Dwelling Units # DUs , Noise Reduction · · ·-···-· ····---·· :-Min ··--i Avg Tilax·:= i dB ... \~B i dB All Selected 3/ 0.0/ 0.0; 0.0, All Impacted ---. i Q! ... O.Qi O.Oi O.Oi Affthat meet NR Goal.. ·-···--o .Oi ·o.oT 0.01 O.Oj C:\TNM25\Program\Grand Jefferson\Existing\With Project 1 3 September 2