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HomeMy WebLinkAboutAppendix F - Technical Noise Study DRAFT - TECHNICAL NOISE STUDY FOR: PS BUSINESS PARKS 124 AIRPORT BOULEVARD AND 100 PRODUCE AVENUE SOUTH SAN FRANCISCO, CA RGD Project #: 20-022 PREPARED FOR: Raney Planning & Management, Inc. 1501 Sports Drive, Suite A Sacramento, CA 95834 PREPARED BY: Alan Rosen Harold Goldberg, P.E. Tsz “Anthony” Wong DATE: 31 July 2020 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 2 1 Introduction This report analyzes the potential off-site noise impacts associated with the proposed project at 124 Airport Boulevard and 100 Produce Avenue in South San Francisco. The project consists of the demolition of six existing commercial buildings and the development of a new 7-story residential building at 124 Airport Boulevard (“Building 1”) and a new 7-story residential building at 100 Produce Avenue (“Building 2”). Both buildings feature 5 levels of apartment units over 2 levels of parking with a total combined 480 new dwelling units. 2 Fundamental Concepts of Environmental Noise Noise can be defined as unwanted sound. It is commonly measured with an instrument called a sound level meter. The sound level meter captures the sound with a microphone and converts it into a number called a sound level. Sound levels are expressed in units of decibels. To correlate the microphone signal to a level that corresponds to the way humans perceive noise, the A-weighting filter is used. A-weighting de-emphasizes low-frequency and very high- frequency sound in a manner similar to human hearing. The use of A-weighting is required by most local General Plans as well as federal and state noise regulations (e.g. Caltrans, EPA, OSHA and HUD). The abbreviation dBA is sometimes used when the A-weighted sound level is reported. Because of the time-varying nature of environmental sound, there are many descriptors that are used to quantify the sound level. Although one individual descriptor alone does not fully describe a particular noise environment, taken together, they can more accurately represent the noise environment. The maximum instantaneous noise level (Lmax) is often used to identify the loudness of a single event such as a car pass-by or airplane flyover. To express the average noise level the Leq (equivalent noise level) is used. The Leq can be measured over any length of time but is typically reported for periods of 15 minutes to 1 hour. The background noise level (or residual noise level) is the sound level during the quietest moments. It is usually generated by steady sources such as distant freeway traffic. It can be quantified with a descriptor called the L90 which is the sound level exceeded 90 percent of the time. There are other statistical descriptors that are used, often times as part of a local noise ordinance. These descriptors are used since local ordinances will have limits based on the number of minutes per hour that an intrusive sound may exceed a specified limit. For example, if a specified noise level cannot be exceeded more than 30 minutes in an hour that is referred to as the L50. The L50 is also referred to as the median noise level. To quantify the noise level over a 24-hour period, the Day/Night Average Sound Level (DNL or Ldn) or Community Noise Equivalent Level (CNEL) is used. These descriptors are averages like the Leq except they include a 10 dB penalty during nighttime hours (and a 5 dB penalty during evening hours in the CNEL) to account for peoples increased sensitivity during these hours. The CNEL and DNL are typically within one decibel of each other. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 3 In environmental noise, a change in noise level of 3 dB is considered a just noticeable difference. A 5 dB change is clearly noticeable, but not dramatic. A 10 dB change is perceived as a halving or doubling in loudness. Examples of common noise sources and their corresponding noise levels are provided in the following table. Sound Source Sound Pressure Level (dBA) Air raid siren at 50 ft (threshold of pain)(1) 120 Maximum levels in audience at rock concerts(1) 110 Train horn at 100 ft(3) 103 On platform by passing subway train(1) 100 On sidewalk by passing heavy truck or bus(1) 90 Commuter train traveling at 79 mph at 100 ft(3) 88 On sidewalk by passing automobiles(1) 70 Typical gas and electric powered leaf blower at 50 ft(2) 68 - 71 Conversational speech(4) 60 Typical urban area background/busy office(1) 60 Typical suburban area background(1) 50 Quiet suburban area at night(1) 40 Typical rural area at night(1) 30 Isolated broadcast studio(1) 20 Audiometric (hearing testing) booth(1) 10 Threshold of hearing(1) 0 1Cowan, James P. Handbook of Environmental Acoustics. Van Nostrand Reinhold, 1994. 2California Environmental Protection Agency, Air Resources Board. Mobile Source Control Division (2000). A report to the California legislature on the potential health and environmental impacts of leaf blowers. Retrieved from https://ww3.arb.ca.gov/msprog/leafblow/leafblow.htm 3California High-Speed Rail Authority. (2018). How do High-Speed Train Noise Levels Compare to Traditional Trains. Retrieved from https://www.hsr.ca.gov/communication/info_center/factsheets.aspx 4Everest, Fredrick Alton, and Ken C. Pohlmann. Master Handbook of Acoustics, 5th Ed. McGraw-Hill, 2009. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 4 Vibration is an oscillatory motion which can be described in terms of the displacement, velocity, or acceleration. Because the motion is oscillatory, there is no net movement. Displacement is the easiest descriptor to understand. For a vibrating floor, the displacement is simply the distance that a point on the floor moves away from its static position. The velocity represents the instantaneous speed of the floor movement. The peak particle velocity (PPV) is the descriptor used in monitoring of construction vibration since it is related to the stresses that are experienced by buildings. The table below shows the guideline criteria for building damage by Caltrans. The criteria are in terms of the peak particle velocity (PPV) expressed in inches per second. Guideline Vibration Damage Potential Threshold Criteria (Caltrans Table 191) 1 Caltrans, Transportation and Construction Vibration Guidance Manual, September 2013. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 5 3 Regulatory Framework 3.1 City of South San Francisco General Plan The Noise Element of the South San Francisco General Plan has guidelines for noise and land use compatibility. These guidelines are summarized in Table 9.2-1. Table 9.2-1: Land Use Criteria for Noise-Impacted Areas PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 6 3.2 City of South San Francisco Municipal Code Chapter 8.32 of the City’s Noise Ordinance specifies maximum permissible sound levels to be generated by any property within the City. The maximum allowable level is determined by the land use category of the receiving property. These levels are summarized in Table 8.32.030. The levels shown in Table 8.32.030 are applicable for noises that occur up to 30 minutes per hour. Higher noise levels are allowed, but for shorter periods of time. Higher noise levels are also allowed if the ambient noise level is higher than the standards in Table 8.32.030. Table 8.32.030: Noise Level Standards PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 7 Section 8.32.050 (d) identifies a special provision which allows construction activities with a City permit between the hours of 8 a.m. to 8 p.m. on weekdays, 9 a.m. to 8 p.m. on Saturdays and 10 a.m. to 6 p.m. on Sundays and holidays. Other hours may be authorized by obtaining a permit, provided the construction meets at least one of the following requirements: 1. No individual piece of equipment shall produce a noise level exceeding 90 dB at a distance of 25 feet. If the device is housed within a structure or trailer on the property, the measurement shall be made outside the structure at a distance as close to 25 feet from the equipment as possible. 2. The noise level at any point outside of the property plane2 of the project shall not exceed 90 dB. 3.3 Airport Land Use Compatibility Plan The 2012 Comprehensive Airport Land Use Compatibility Plan for the Environs of San Francisco International Airport has guidelines for noise and land use compatibility. These guidelines are summarized in Table IV-1. 2 According to the City’s Municipal Code Section 8.32.020, property plane means vertical plane including the property line which determines the property boundaries in space. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 8 3.4 CEQA Guidelines In accordance with Section XI of Appendix G of the CEQA Guidelines, a proposed project could have a significant environmental impact if it would result in: a. 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 . b. Generation of excessive groundborne vibration or groundborne noise levels. c. 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. 4 Existing Noise Environment The project site is located to the west of Airport Boulevard and Produce Avenue and is bounded to the west and south by Colma Creek. The Caltrain rail line is adjacent to the north side of the project near Building 1. The existing railroad tracks would be as close as 58 feet from the proposed Building 1. US-101 is located approximately 450 feet east of the project site. The major noise sources affecting the study area are railroad activities on the Caltrain rail line and vehicular traffic on US-101 and local roads. Other noise sources include aircraft and commercial/industrial activities. The surrounding land uses are mostly limited to commercial and light industrial. Noise sensitive land uses are typically defined as residences, schools, place of worship, and hospitals. The nearest land uses are zoned “Business Commercial” and the nearest residential zones (“Downtown High-Density Residential Core”) are located north of the railroad tracks, generally more than 500 feet from the project site. There are hotel buildings along the Airport Boulevard, Mitchell Avenue, and South Airport Boulevard located to the east of Airport Boulevard that are within 1,000 feet but generally more than 350 feet from the project site. Noise measurements were conducted on June 9 -11, 2020 to quantify the existing noise environment. The measurements consisted of four on-site long-term, 48-hour, measurements (Location LT-1 to LT-4) and five short-term, 15-minute, measurements (Location ST-1 to ST-5). The noise measurement locations are shown in Figure 1. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 9 Figure 1: Noise Measurement and Receiver Locations Source: Map data © 2020 Google The long-term measurement at Location LT-1 was made on a tree near the north edge of Building 1 site along the railroad tracks. The microphone was located approximately 12 feet above ground. At Location LT-1, noise from railroad operations generated maximum noise levels Lmax of 76 to 95 dBA with a typical Lmax of 86 to 88 dBA. The CNEL was 67 dBA, mostly due to noise from railroad operations. The long-term measurement at Location LT-2 was made on a utility pole along San Mateo Avenue. The microphone was located approximately 12 feet above ground. At Location LT-2, traffic noise from San Mateo Avenue was the dominant noise source. The CNEL was 74 dBA. The long-term measurement at Location LT-3 was made on a utility pole on the Building 2 site along Produce Avenue. The microphone was located approximately 12 feet above ground. At Location LT-3, traffic noise from Produce Avenue was the dominant noise source. The CNEL was 76 dBA. The long-term measurement at Location LT-4 was made near the Building 1 west property line. This location is near the City sewer pump station just west of the site. The PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 10 microphone was located approximately 8 feet above ground. At Location LT-4, noise from railroad operations generated maximum instantaneous noise levels (Lmax) typically ranging from 76 to 83 dBA. On June 10, 2020, noise from a train horn generated an Lmax of 102 dBA. The CNEL was 65 dBA. The five short-term noise measurements were made near the various proposed building setbacks, 5 feet above ground. At Location ST-1, noise from rail operations was the dominant noise source. At the other locations ST-2 to ST-5, the dominant noise source was roadway traffic. The noise measurements were made with a Larson Davis Model 820 or 824 Sound Level Meter meeting Type 1 specifications (ANSI S1.4). Calibrations were checked with a Larson Davis Cal200 calibrator. Coronavirus Pandemic Based on our observations and experience with other projects, it appears that the coronavirus pandemic has affected traffic volumes on roadways in the Bay Area. To quantify any potential reduction in traffic volumes and noise levels due to the pandemic, we set up a long-term, noise monitor at the intersection of East Grand Avenue and the US-101 northbound off-ramp. The measurement lasted two days and was compared with the measured noise level in 2017 at the same location from a prior project. When comparing the 2020 and 2017 noise measurements, we are able to see that the current noise level (CNEL) is 1 dBA less than the 2017 CNEL. Based on this comparison, we are adding 1 dBA to the measured 2020 CNEL to represent the “existing” noise environment once traffic volumes return to normal. The long-term noise measurement results are summarized in Table 1. Graphs showing the hourly noise levels at each monitoring location are shown in Figures 2 to 5. Table 1: Long-term Noise Measurement Summary Location CNEL, dBA Measured Adjusted for Reduced Traffic due to Coronavirus Pandemic LT-1 67 68 LT-2 74 75 LT-3 76 77 LT-4 65 66 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 11 Figure 2: Long-term Noise Measurement Results at Location LT-1 CNEL 67 dBA (CNEL 68 adjusted) Figure 3: Long-term Noise Measurement Results at Location LT-2 CNEL 74 dBA (CNEL 75 dBA adjusted) PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 12 Figure 4: Long-term Noise Measurement Results at Location LT-3 CNEL 76 dBA (CNEL 77 dBA adjusted) Figure 5: Long-term Noise Measurement Results at Location LT-4 CNEL 64 dBA (CNEL 65 dBA adjusted) PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 13 Table 2: Short-Term Noise Measurement Results – 11 June 2020 Site Location Time Leq L50 Lmax CNEL* Pandemic adjusted CNEL** ST-1 Near setback of Building 1 from railroad tracks 1:15 PM – 1:30 PM 67 60 Traffic: 56 – 63 Med Trucks: 59 Heavy Trucks: 61, 63, 64 Jets: 62 Construction activities near railroad tracks: 60, 61, 64 Construction backup beeper: < 60 Train: 81, 88 65 66 ST-2 Near setback of Building 1 from Airport Boulevard 1:33 PM – 1:48 PM 68 67 Traffic: 69 – 75 Med Trucks: 69, 74 Heavy Trucks: 74 – 75 Buses: 66 – 69 Jet: < 65 72 73 ST-3 Near setback of Building 2 from Produce Avenue 2:09 PM – 2:25 PM 71 70 Traffic: 71 – 74 Med Trucks: 67, 73 – 77 Heavy Trucks: 72, 75, 77 Bus: 72 75 76 ST-4 Near setback of Building 2 from San Mateo Avenue 2:34 PM – 2:49 PM 69 66 Traffic: 66 – 71 Med Trucks: 65 – 70, 77 Heavy Trucks: 66 – 75, 86 Jet: 73 72 73 ST-5 Southwest side of Building 2 near Colma Creek 2:58 PM – 3:13 PM 59 58 Heavy Truck on San Mateo Avenue: 57, 65 Jet: 65 62 63 *CNEL calculated based on correlation between simultaneous long-term and short-term measurements. ** includes a 1 dBA factor to account for traffic volume reduction during coronavirus pandemic (see coronavirus section above). PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 14 Future Caltrain Operations South San Francisco Caltrain Station Relocation The project site is located approximately 0.5 miles from the current South San Francisco Caltrain station to the north. The South San Francisco Caltrain station is being relocated a few hundred feet south. Caltrain Electrification Caltrain is planning for the electrification of their rail line between San Francisco and San Jose. Although the trains will likely be quieter due to the electric propulsion, according to the Peninsula Corridor Electrification Project FEIR (Appendix C), the number of total daily trains will increase from 92 to 114 trains per day. This would include 23 additional trains during the daytime hours (7 AM to 10 PM) and one fewer train during the nighttime (10 PM to 7 AM). This change in number of trains corresponds to an increase in Ldn of less than 1 dBA. 5 Land Use Compatibility Evaluation of land use compatibility for noise sources other than aircraft is not required in a CEQA study. However, based on the noise measurements, the project site is subjected to noise levels between CNEL of 63 to 76 dBA. The City of South San Francisco General Plan’s land use noise criteria table (Table 9.2 -1) shows that residential development exposed between CNEL 65 to 70 requires analysis of noise reduction requirements and residential development exposed to over CNEL 70 dBA should not be undertaken. The City’s General Plan Policy 9-I-6 requires new noise-sensitive development in areas subject to CNEL greater than 65 dBA to obtain the services of a professional acoustical engineer to provide a technical analysis and design of mitigation measures. The analysis should take into account noise from future traffic and future traffic rail operations including Caltrain electrification and the potential for High-Speed Rail. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 15 6 CEQA Impact Assessment 6.1 Construction Noise (CEQA Checklist a) 6.1.1 Thresholds of Significance The City’s Municipal Code promulgates criteria for construction noise based on hours of operation. Therefore, for the purposes of this assessment, construction noise is considered significant if it: • Occurs outside the allowable hours of operation or exceeds the special provisions of Municipal Code Section 8.32.050 (individual equipment exceeds 90 dB at 25 feet and 90 dB at any point outside the property plane) • Causes ambient noise levels to increase significantly at nearby noise sensitive receptors 6.1.2 Construction Noise Impact Assessment Construction activities would last about 34 months and include the demolition of the existing buildings on the project site and the construction of the two new residential buildings. Table 3 shows the project’s construction phases with start and end dates, and the type of equipment used3. Table 3: Construction Phases and Equipment Qty Construction Phase and Equipment Start Date End Date Hours/day Total Work Days Average Hours per day Demolition 11/12/2021 12/24/2021 30 2 Concrete/Industrial Saws 4 5 0.7 2 Excavators 6 25 5.0 1 Rubber-Tired Dozers 4 25 3.3 1 Tractors/Loaders/Backhoes 6 10 2.0 Site Preparation 12/25/2021 1/1/2022 5 1 Rubber Tired Dozers 4 4 3.2 2 Tractors/Loaders/Backhoes 4 2 1.6 Grading / Excavation 1/2/2022 3/27/2022 60 2 Excavators 6 10 1.0 2 Graders 6 25 2.5 3 Pappani, Nick, Raney Planning and Management, Inc. “RE: checking in Ps Biz Park.” Email to Alan Rosen, RGD Acoustics, Inc. 16 April 2020. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 16 Qty Construction Phase and Equipment Start Date End Date Hours/day Total Work Days Average Hours per day 2 Tractors/Loaders/Backhoes 4 5 0.3 Trenching 3/28/2022 4/11/2022 10 1 Tractor/Loader/Backhoe 8 4 3.2 Building - Exterior 2/27/2022 7/16/2023 360 1 Tower Crane (electric) 8 260 5.8 1 Mobile Crane 4 156 1.7 2 Forklifts 6 360 6.0 3 Welders 3 90 0.8 Building - Interior/Architectural Coating 1/17/2023 3/12/2024 300 2 Aerial Lift 7 200 4.7 Paving 1/12/2024 8/23/2024 160 1 Cement and Mortar Mixers 2 30 0.4 1 Pavers 8 8 0.4 1 Rollers 8 8 0.4 1 Tractors/Loaders/Backhoes 4 40 1.0 Table 4 shows typical noise levels for the construction equipment that is expected to be used for the project. Table 4 also shows the noise levels at a distance of 25 feet for comparison with the City noise ordinance. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 17 Table 4: Construction Equipment Noise Levels Construction Equipment Ref. Noise Level at 50 feet, dBA* Adjustment for Distance of 25 feet Calculated Noise Level at 25 feet, dBA Concrete/Industrial Saw 90 6 96 Excavator 81 6 87 Rubber Tired Dozer 82 6 88 Backhoe 78 6 84 Scraper 84 6 90 Tractor 84 6 90 Loader 79 6 85 Crane 81 6 87 Forklift 83 6 89 Generator 81 6 87 Welder 74 6 80 Man lift 75 6 81 Cement and Mortar Mixer 79 6 85 Paving Equipment 77 6 83 Roller 80 6 86 *Source: FHWA, Roadway Construction Noise Model, 2006. Table 5 shows the calculated maximum instantaneous exterior noise levels from project-related construction equipment at the nearby office/industrial land uses. Table 6 shows the calculated maximum instantaneous exterior noise levels from project-related construction equipment at the nearest hotels. The calculated exterior noise levels are based on the methodology of the Federal Highway Administration’s (FHWA) Roadway Construction Noise Model (2006). PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 18 Table 5: Construction Equipment Noise Levels at Nearby Land Uses Construction Equipment Maximum Noise Levels (Lmax) for Typical Construction Activities, dBA Nearest commercial building to the south across Colma Creek (1461 San Mateo Ave) Nearest commercial building to the north across railroad tracks (5 S Linden Ave) Nearest industrial building to the east across Airport Blvd (60 Airport Blvd) Concrete/Industrial Saws 78 83 82 Excavators 69 74 73 Rubber Tired Dozers 70 75 74 Backhoe 66 71 70 Scrapers 72 77 76 Tractor 72 77 76 Loader 67 72 71 Crane 69 74 73 Forklifts 71 76 75 Generator 69 74 73 Welders 62 67 66 Man lift 63 68 67 Cement and Mortar Mixers 67 72 71 Paving Equipment 65 70 69 Rollers 68 73 72 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 19 Table 6: Construction Equipment Noise Levels at Nearest Hotels Construction Equipment Maximum Noise Levels (Lmax) for Typical Construction Activities, dBA Hotel V (225 S Airport Blvd) La Quinta Inn & Suites (20 Airport Blvd) Concrete/Industrial Saws 72 72 Excavators 63 63 Rubber Tired Dozers 64 64 Backhoe 60 60 Scrapers 66 66 Tractor 66 66 Loader 61 61 Crane 63 63 Forklifts 65 65 Generator 63 63 Welders 56 56 Man lift 57 57 Cement and Mortar Mixers 61 61 Paving Equipment 59 59 Rollers 62 62 Noise from construction activities may be noticeable at times at the nearby buildings. For example, the measured outdoor ambient Leq along Airport Boulevard (Location ST-2) is 68 dBA while the calculated maximum noise levels from construction activities are generally about 10 dBA higher at the industrial building across Airport Boulevard when the equipment is near the project’s east property line closest to the building. The nearest hotels (Hotel V and La Quinta Inn & Suites) are approximately 380 feet from the project site boundary. Based on the distance between the hotel building and US-101, the exterior noise levels due to US-101 traffic is estimated to be greater than the measured noise levels (Leq of 72 to 74 dBA during the day) at Location LT-3. Table 6 shows that the noise from project-related construction would generally be less than 66 dBA but occasionally up to 72 dBA outdoors. This is generally less than the noise levels generated by ambient noise sources (i.e. traffic) but may be noticeable at times. Construction activities are allowed by the City’s code during allowable construction hours provided that noise from individual equipment does not exceed 90 dBA at 25 feet and the noise at any point outside the property plane does not exceed 90 dBA. Table 4 shows that all the individual construction equipment would generate less than 90 dBA at a distance of 25 feet except for concrete saws. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 20 Concrete/industrial saw is expected to be primarily used at distances of more than 50 feet from the property plane. The noise level from a concrete saw would not exceed the property plane noise limit of 90 dBA at a distance of 50 feet or more from the property plane. However, there may be times when these could be used close to the property line. The concrete saw would only be used for 5 days, four hours per day, during the demolition phase. There is a potential that the concrete saw could exceed the noise ordinance limit when it is close to the property line. However, at the nearest hotels, construction noise would be less than the noise levels generated by intermittent ambient noise sources and is not expected to cause a significant increase in the ambient noise level. Additionally, most of the construction equipment are not expected to generate noise levels in excess of the noise ordinance limit. This is a less than significant impact with Mitigation Measure NO-1 (“Construction Noise Minimization and Mitigation”). Mitigation Measure NO-1: Construction Noise Minimization and Mitigation In order to minimize the potential impact associated with construction, the following is recommended: • All construction equipment shall be equipped with mufflers and sound control devices (e.g., intake silencers and noise shrouds) that are in good condition and appropriate for the equipment. • Maintain all construction equipment to minimize noise emissions. • Stationary equipment shall be located on the site to maintain the greatest possible distance to the existing office buildings, where feasible. • Use temporary noise barriers around noisier equipment, where feasible, when the noise ordinance limits cannot be achieved. • Unnecessary idling of internal combustion engines should be strictly prohibited. • Provide advance notification to surrounding land uses disclosing the construction schedule, including the various types of activities that would be occurring throughout the duration of the construction period. • The construction contractor shall provide the name and telephone number an on-site construction liaison. If construction noise is found to be intrusive to the community (complaints are received), the construction liaison shall investigate the source of the noise and require that reasonable measures be implemented to correct the problem. • Schedule high noise-producing activities during times when they would be least likely to interfere with the noise sensitive activities of the neighboring land uses, when possible. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 21 6.2 Construction Vibration (CEQA Checklist b) 6.2.1 Thresholds of Significance Neither CEQA, City, nor the State specifies acceptable vibration levels from construction activities. For the purposes of this assessment, the guideline criteria for building damage recommended by Caltrans4 is used. The construction vibration damage criteria range from a Peak Particle Velocity (PPV) of 0.25 inches/sec for historic and some old buildings to 0.5 inches/sec for modern industrial/commercial buildings. 6.2.2 Construction Vibration Impact Assessment The nearest neighboring building is a commercial building on South Linden Ave north of the Caltrain railroad tracks. At the closes point, the project site is approximately 108 feet from the commercial building. Table 7 shows the calculated construction vibration levels at the commercial building and the nearest industrial building. Other buildings are located across roadways or the Colma Creek at distances of more than 130 feet from the nearest project site boundary and would be exposed to less construction vibration levels. Table 7: Calculated Vibration Levels from Construction Equipment PPV (inches/sec) Nearest commercial building north of railroad tracks (5 S Linden Ave) Nearest industrial building east of Airport Blvd. (60 Airport Blvd) 108 feet from Equipment 130 feet from Equipment Vibratory Roller 0.02 0.02 Hoe Ram 0.02 0.02 Large Bulldozer 0.01 0.01 Caisson Drilling 0.01 0.01 Loaded Trucks 0.01 0.01 Jackhammer 0.01 0.01 Small Bulldozer < 0.01 < 0.01 Table 7 shows that construction vibration levels are expected to be less than the potential building damage thresholds of a PPV of 0.5 inches/sec for modern industrial/commercial buildings. Since vibration from construction would not exceed the threshold for potential building damage, this is considered less than significant. 4 Caltrans, Transportation and Construction Vibration Guidance Manual, September 2013. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 22 6.3 Operational Noise (CEQA Checklist a) 6.3.1 Traffic Noise 6.3.1.1 Thresholds of Significance Neither the CEQA checklist nor the City’s General Plan specify a quantitative method for determining whether a project would cause a significant increase in noise. In general, an increase of 3 dBA is just noticeable, a change of 5 dBA is clearly noticeable and a change of 10 dBA is perceived as a doubling (or halving). In October 2009, an EIR for the Gateway Business Park Master Plan promulgated impact thresholds based on these increases. Therefore, for the purposes of this impact assessment, the following increases in traffic noise, based on the Gateway Business Park Master Plan EIR are considered to be significant: Project Impact: • Increase of 5 dBA or greater if future noise level is within the normally acceptable range. • Increase of 3 dBA or greater if future noise level is above the normally acceptable range. Cumulative Impact: In the future, traffic will typically increase due to a project and general growth that is not directly related to the project. For the purposes of this analysis, the project’s contribution to future traffic noise is considered “cumulatively considerable” if the future increase in traffic noise due to the project is greater than 1 dBA as follows: • Cumulative increase of 5 dBA or greater (future noise level is within the normally acceptable range) AND the project’s contribution is greater than 1 dBA. • Cumulative increase of 3 dBA or greater (future noise level is above the normally acceptable range) AND the project’s contribution is greater than 1 dBA. 6.3.1.2 Traffic Noise Calculation Methodology In order to calculate the increase in traffic noise due to the project, existing and future traffic noise levels were calculated using the Federal Highway Administration’s Traffic Noise Model (TNM 2.5) with traffic volumes5 from Fehr & Peers. The TNM model takes into account the vehicle class, speed, road surface, and distance from roadway to receptor. The TNM model calculates an Leq based on peak-hour traffic data at a distance of 50 feet from the roadway centerline. The CNEL at each of the modeling points was determined based on the difference between the peak-hour Leq and CNEL measured at the long-term monitoring locations. 5 Fehr & Peers, 124 Airport / 100 Produce Administrative Draft Transportation Impact An alysis, July 2020. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 23 6.3.1.3 Project Generated Traffic Noise Impact Tables 8, 9 and 10 show the existing and future traffic noise levels for the following development scenarios: • Existing plus Project • Existing plus Project with “Reconfiguration alternative 5” • Existing plus Project with “Reconfiguration alternative 6” Reconfiguration alternative 5 and alternative 6 are two conceptual design alternatives of the Produce Avenue/Utah Avenue interchange project which is not yet fully funded, nor has a design been selected yet. Tables 8 to 10 show that the increase in traffic noise would be less than 3 dBA for all roadways in the study area under the existing plus project condition (with and without reconfiguration alternative 5 or 6). For commercial and industrial uses, the increases in traffic noise levels due to the project are less than both the significant increase thresholds of 5 dBA if the future noise level is within the normally acceptable range and 3 dBA if the future noise level exceeds the normally acceptable range. Therefore, the increase in traffic noise due to the project is considered a less than significant impact. Table 8: Increase in Traffic Noise Levels due to Project Roadway CNEL at 50 feet, dBA Existing Volume Existing + Project Volume Increase due to Project Airport Blvd north of San Mateo Ave 73.2 73.5 0.3 South Airport Blvd east of Produce Ave 72.9 72.9 < 0.1 Mitchell Ave to Wondercolor Ln 71.6 71.7 0.1 south of Wondercolor Ln 71.3 71.3 < 0.1 Gateway Blvd north of South Airport Blvd 70.8 70.8 < 0.1 Produce Ave south of San Mateo Ave 74.7 74.8 0.1 San Mateo Ave west of Airport Blvd 73.1 73.5 0.4 Mitchell Ave east of South Airport Blvd 71.2 71.2 < 0.1 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 24 Roadway CNEL at 50 feet, dBA Existing Volume Existing + Project Volume Increase due to Project Wondercolor Ln east of South Airport Blvd 60.2 60.2 < 0.1 US-101 northbound on/off-ramp at Wondercolor Ln 75.6 75.6 < 0.1 Table 9: Increase in Traffic Noise Levels due to Project and Reconfiguration Alternative 5 Roadway CNEL at 50 feet, dBA Existing Volume Existing + Project Volume Increase due to Project Airport Blvd north of San Mateo Ave 73.2 73.5 0.3 South Airport Blvd east of Produce Ave 72.9 72.9 < 0.1 Mitchell Ave to Wondercolor Ln 71.6 71.7 0.1 south of Wondercolor Ln 71.3 71.3 < 0.1 Gateway Blvd north of South Airport Blvd 70.8 70.8 < 0.1 Produce Ave south of San Mateo Ave 74.7 74.7 < 0.1 San Mateo Ave west of Airport Blvd 73.1 73.4 0.3 Mitchell Ave east of South Airport Blvd 71.2 71.2 < 0.1 Wondercolor Ln east of South Airport Blvd 60.2 60.2 < 0.1 US-101 northbound on/off-ramp at Wondercolor Ln 75.6 75.6 < 0.1 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 25 Table 10: Increase in Traffic Noise Levels due to Project and Reconfiguration Alternative 6 Roadway CNEL at 50 feet, dBA Existing Volume Existing + Project Volume Increase due to Project Airport Blvd north of San Mateo Ave 73.2 73.5 0.3 South Airport Blvd east of Produce Ave 72.9 72.9 < 0.1 Mitchell Ave to Wondercolor Ln 71.6 71.7 0.1 south of Wondercolor Ln 71.3 71.3 < 0.1 Gateway Blvd north of South Airport Blvd 70.8 70.8 < 0.1 Produce Ave south of San Mateo Ave 74.7 74.8 0.1 San Mateo Ave west of Airport Blvd 73.1 73.5 0.4 Mitchell Ave east of South Airport Blvd 71.2 71.2 < 0.1 Wondercolor Ln east of South Airport Blvd 60.2 60.2 < 0.1 US-101 northbound on/off-ramp at Wondercolor Ln 75.6 75.6 < 0.1 6.3.1.4 Cumulative Traffic Noise Impact In the future, traffic will increase due to general growth in the area that is not directly related to the project. Table 11 to 13 show the future traffic noise levels for the following scenarios evaluated in the traffic analysis: • Cumulative plus Project • Cumulative plus Project with “Reconfiguration alternative 5” • Cumulative plus Project with “Reconfiguration alternative 6” The future traffic volumes are for cumulative year 2040 scenario in the traffic study. Tables 11, 12 and 13 show that the increase in traffic noise from cumulative development would be less than 3 dBA for all roadways in the study area. Therefore, the project’s contribution to increases in cumulative traffic noise is less than significant. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 26 Table 11: Cumulative Increase in Traffic Noise Levels due to Project Roadway CNEL at 50 feet, dBA Existing Volume Cumulative Volume Cumulative + Project Volume Existing to Future with Project Increase in CNEL Project Contribution to Future CNEL Airport Blvd north of San Mateo Ave 73.2 73.7 74.0 0.8 0.3 South Airport Blvd east of Produce Ave 72.9 73.4 73.5 0.6 0.1 Mitchell Ave to Wondercolor Ln 71.6 72.1 72.2 0.6 0.1 south of Wondercolor Ln 71.3 71.7 71.8 0.5 0.1 Gateway Blvd north of South Airport Blvd 70.8 72.2 72.2 1.4 < 0.1 Produce Ave south of San Mateo Ave 74.7 75.0 75.1 0.4 0.1 San Mateo Ave west of Airport Blvd 73.1 73.6 74.0 0.9 0.4 Mitchell Ave east of South Airport Blvd 71.2 71.7 71.7 0.5 < 0.1 Wondercolor Ln east of South Airport Blvd 60.2 60.8 60.8 0.6 < 0.1 US-101 northbound on/off-ramp at Wondercolor Ln 75.6 75.9 75.9 0.3 < 0.1 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 27 Table 12: Cumulative Increase in Traffic Noise Levels due to Project and Reconfiguration Alternative 5 Roadway CNEL at 50 feet, dBA Existing Volume Cumulative Volume with Reconfig. Alt. 5 Cumulative + Project Volume Existing to Future with Project Increase in CNEL Project Contribution to Future CNEL Airport Blvd north of San Mateo Ave 73.2 74.3 74.5 1.3 0.2 South Airport Blvd east of Produce Ave 72.9 72.3 72.4 -0.5 0.1 Mitchell Ave to Wondercolor Ln 71.6 71.5 71.5 -0.1 < 0.1 south of Wondercolor Ln 71.3 71.2 71.2 -0.1 < 0.1 Gateway Blvd north of South Airport Blvd 70.8 72.1 72.1 1.3 < 0.1 Produce Ave south of San Mateo Ave 74.7 74.4 74.4 -0.3 < 0.1 San Mateo Ave west of Airport Blvd 73.1 73.0 73.3 0.2 0.3 Mitchell Ave east of South Airport Blvd 71.2 71.6 71.6 0.4 < 0.1 Wondercolor Ln east of South Airport Blvd 60.2 61.1 61.1 0.9 < 0.1 US-101 northbound on/off-ramp at Wondercolor Ln 75.6 76.1 76.1 0.5 < 0.1 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 28 Table 13: Cumulative Increase in Traffic Noise Levels due to Project and Reconfiguration Alternative 6 Roadway CNEL at 50 feet, dBA Existing Volume Cumulative Volume with Reconfig. Alt. 6 Cumulative + Project Volume Existing to Future with Project Increase in CNEL Project Contribution to Future CNEL Airport Blvd north of San Mateo Ave 73.2 74.2 74.5 1.3 0.3 South Airport Blvd east of Produce Ave 72.9 73.5 73.5 0.6 < 0.1 Mitchell Ave to Wondercolor Ln 71.6 72.0 72.1 0.5 0.1 south of Wondercolor Ln 71.3 71.7 71.7 0.4 < 0.1 Gateway Blvd north of South Airport Blvd 70.8 72.4 72.4 1.6 < 0.1 Produce Ave south of San Mateo Ave 74.7 75.1 75.1 0.4 < 0.1 San Mateo Ave west of Airport Blvd 73.1 74.3 74.6 1.5 0.3 Mitchell Ave east of South Airport Blvd 71.2 71.8 71.8 0.6 < 0.1 Wondercolor Ln east of South Airport Blvd 60.2 61.2 61.2 1.0 < 0.1 US-101 northbound on/off-ramp at Wondercolor Ln 75.6 76.1 76.1 0.5 < 0.1 PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 29 6.3.2 Mechanical Equipment (HVAC) (CEQA Checklist a) 6.3.2.1 Thresholds of Significance Mechanical equipment noise that exceeds the limits set forth in Table 8.32.030 of the City’s municipal code is considered a significant impact. 6.3.2.2 Mechanical Equipment Noise Impact Assessment The proposed project buildings will have mechanical equipment generally associated with building ventilation. These will consist of rooftop air-conditioning units, and ventilation fans. There may also be other equipment such as emergency engine-generators. At the time of this report, the project buildings are proposed to have two kinds of heat pumps (Daikin and Goodman) on the roofs of Building 1 and Building 2 to serve the residential units. According to the applicant, 68% of the heat pumps will be Daikin and 32% will be Goodman7. Each of the buildings will include a dedicated outside air system (Samsung DOAS) for the corridors. According to the City’s municipal code, maximum permissible sound levels from the project are determined by the land use category of the receiving property. The permissible levels are in terms of L50 and are shown in Municipal Code Table 8.32.030. The City designates land to the east across Airport Boulevard and Produce Avenue as “freeway commercial” (FC) and land to the north of the project site and west of the project across Colma Creek as “mixed industrial” (MI). Therefore, the project must limit mechanical equipment noise such that noise does not exceed the noise level standards for receiving commercial and receiving industrial land uses. The standard noise level limits are an L50 of 65 dBA during daytime (7 AM to 10 PM) and L50 of 60 dBA at nighttime (10 PM to 7 AM) at the commercial land uses or an L50 of 70 dBA at all times at the nearby industrial land uses. According to Municipal Code Section 8.32.030, if the measured ambient noise level for any area is higher than the standard noise level limits, then the standard noise level limits are adjusted upwards to the ambient noise level. Based on calculations of mechanical noise utilizing the available equipment information, noise from the proposed heat pumps and dedicated outside air system on the project building rooftops would be an L50 of 57 dBA or less at the property north of the railroad tracks, an L50 of 59 dBA or less at the properties across Colma Creek, and an L50 of 60 dBA or less at the properties across Airport Boulevard/Produce Avenue. Since mechanical equipment noise would be less than the standard noise ordinance limits, this is considered a less than significant impact. However, detailed analysis of noise from the project’s final mechanical equipment system design should be conducted during the architectural design phase to confirm that the equipment will comply with the City’s municipal code requirements. 7 Anderson, Zach, Hanover Company. “FW: 124 Airport Blvd – specs on outdoor mechanical equipment requested” Email to Nick Pappani, Raney Planning & Management, Inc. 30 July 2020. PS Business Parks, South San Francisco DRAFT - 31 July 2020 Technical Noise Study Page 30 6.4 Airport Noise (CEQA Checklist c) 6.4.1.1 Thresholds of Significance A significant impact would occur if the project would expose people residing or working in the project area to excessive aircraft noise levels (aircraft CNEL of 65 dBA). 6.4.1.2 Airport Noise Impact Assessment According to the 2012 Comprehensive Airport Land Use Compatibility Plan (ALUCP) for the Environs of San Francisco International Airport Exhibit IV-5, the project site is located outside the CNEL 65 dB aircraft noise contour and within “Airport Influence Area B”. Per Policy IP-2, the project has real estate disclosure requirements regarding the potential for annoyances associated with proximity to airport operations (e.g. noise). Per the ALUCP’s Table IV-1, multi-family residential land uses are compatible with aircraft CNEL below 65 dBA, and may be permitted without any special requirements related to the attenuation of aircraft noise. Therefore, this is a less than significant impact. * * *