10192 San Pablo Avenue Residential

Transcription

1 10192 San Pablo Avenue Residential City of El Cerrito, California February 13, 2017 jcb Project # Prepared for: Attn: Lisa Vilhauer Branagh Development Inc Mt. Diablo Boulevard, Suite 200 Lafayette, California Prepared by: Luke Saxelby, INCE Bd. Cert. Vice President Board Certified, Institute of Noise Control Engineering (INCE) 1287 High Street, Auburn, California * (530) (p) * (530) (f)

2 INTRODUCTION The San Pablo Avenue Residential project consists of a 21-unit multi-family residential development located at the southeast corner of San Pablo Avenue and Lincoln Avenue. The project is located in the City of El Cerrito, California. Figure 1 shows the project site plan. Figure 2 shows an aerial photo of the project site. ENVIRONMENTAL SETTING BACKGROUND INFORMATION ON NOISE Fundamentals of Acoustics Acoustics is the science of sound. Sound may be thought of as mechanical energy of a vibrating object transmitted by pressure waves through a medium to human (or animal) ears. If the pressure variations occur frequently enough (at least 20 times per second), then they can be heard and are called sound. The number of pressure variations per second is called the frequency of sound, and is expressed as cycles per second or Hertz (Hz). Noise is a subjective reaction to different types of sounds. Noise is typically defined as (airborne) sound that is loud, unpleasant, unexpected or undesired, and may therefore be classified as a more specific group of sounds. Perceptions of sound and noise are highly subjective from person to person. Measuring sound directly in terms of pressure would require a very large and awkward range of numbers. To avoid this, the decibel scale was devised. The decibel scale uses the hearing threshold (20 micropascals), as a point of reference, defined as 0 db. Other sound pressures are then compared to this reference pressure, and the logarithm is taken to keep the numbers in a practical range. The decibel scale allows a million-fold increase in pressure to be expressed as 120 db, and changes in levels (db) correspond closely to human perception of relative loudness. The perceived loudness of sounds is dependent upon many factors, including sound pressure level and frequency content. However, within the usual range of environmental noise levels, perception of loudness is relatively predictable, and can be approximated by A-weighted sound levels. There is a strong correlation between A-weighted sound levels (expressed as dba) and the way the human ear perceives sound. For this reason, the A-weighted sound level has become the standard tool of environmental noise assessment. All noise levels reported in this section are in terms of A-weighted levels, but are expressed as db, unless otherwise noted. Page 1 of 22

3 Figure 1: Site Plan Rev. 01/18/17

4 2 Project Site A 1 Figure 2: Location & Measurement Sites Legend # # : Continuous (24-hr) Noise Measurement Site :Short-Term Noise Measurement Site Rev. 2/6/17

5 The decibel scale is logarithmic, not linear. In other words, two sound levels 10-dB apart differ in acoustic energy by a factor of 10. When the standard logarithmic decibel is A-weighted, an increase of 10-dBA is generally perceived as a doubling in loudness. For example, a 70-dBA sound is half as loud as an 80-dBA sound, and twice as loud as a 60 dba sound. Community noise is commonly described in terms of the ambient noise level, which is defined as the all-encompassing noise level associated with a given environment. A common statistical tool is the average, or equivalent, sound level (L eq ), which corresponds to a steady-state A weighted sound level containing the same total energy as a time varying signal over a given time period (usually one hour). The L eq is the foundation of the composite noise descriptor, L dn, and shows very good correlation with community response to noise. The day/night average level (L dn ) is based upon the average noise level over a 24-hour day, with a +10-decibel weighing applied to noise occurring during nighttime (10:00 p.m. to 7:00 a.m.) hours. The nighttime penalty is based upon the assumption that people react to nighttime noise exposures as though they were twice as loud as daytime exposures. Because L dn represents a 24-hour average, it tends to disguise short-term variations in the noise environment. Table 1 lists several examples of the noise levels associated with common situations. Appendix A provides a summary of acoustical terms used in this report. Page 4 of 22

6 TABLE 1: TYPICAL NOISE LEVELS Common Outdoor Activities Noise Level (dba) Common Indoor Activities Jet Fly-over at 300 m (1,000 ft) Rock Band Gas Lawn Mower at 1 m (3 ft) Diesel Truck at 15 m (50 ft), Food Blender at 1 m (3 ft) at 80 km/hr (50 mph) Garbage Disposal at 1 m (3 ft) Noisy Urban Area, Daytime Vacuum Cleaner at 3 m (10 ft) Gas Lawn Mower, 30 m (100 ft) Commercial Area Heavy Traffic at 90 m (300 ft) Quiet Urban Daytime Quiet Urban Nighttime Quiet Suburban Nighttime Library Normal Speech at 1 m (3 ft) Large Business Office Dishwasher in Next Room Theater, Large Conference Room (Background) Quiet Rural Nighttime Bedroom at Night, Concert Hall (Background) Broadcast/Recording Studio Lowest Threshold of Human Hearing Lowest Threshold of Human Hearing Source: Caltrans, Technical Noise Supplement, Traffic Noise Analysis Protocol. September, Page 5 of 22

7 Effects of Noise on People The effects of noise on people can be placed in three categories: Subjective effects of annoyance, nuisance, and dissatisfaction Interference with activities such as speech, sleep, and learning Physiological effects such as hearing loss or sudden startling Environmental noise typically produces effects in the first two categories. Workers in industrial plants can experience noise in the last category. There is no completely satisfactory way to measure the subjective effects of noise or the corresponding reactions of annoyance and dissatisfaction. A wide variation in individual thresholds of annoyance exists and different tolerances to noise tend to develop based on an individual s past experiences with noise. Thus, an important way of predicting a human reaction to a new noise environment is the way it compares to the existing environment to which one has adapted: the so-called ambient noise level. In general, the more a new noise exceeds the previously existing ambient noise level, the less acceptable the new noise will be judged by those hearing it. With regard to increases in A-weighted noise level, the following relationships occur: Except in carefully controlled laboratory experiments, a change of 1-dBA cannot be perceived; Outside of the laboratory, a 3-dBA change is considered a just-perceivable difference; A change in level of at least 5-dBA is required before any noticeable change in human response would be expected; and A 10-dBA change is subjectively heard as approximately a doubling in loudness, and can cause an adverse response. Stationary point sources of noise including stationary mobile sources such as idling vehicles attenuate (lessen) at a rate of approximately 6-dB per doubling of distance from the source, depending on environmental conditions (i.e. atmospheric conditions and either vegetative or manufactured noise barriers, etc.). Widely distributed noises, such as a large industrial facility spread over many acres, or a street with moving vehicles, would typically attenuate at a lower rate. Page 6 of 22

8 EXISTING AND FUTURE NOISE AND VIBRATION ENVIRONMENTS EXISTING NOISE RECEPTORS Some land uses are considered more sensitive to noise than others. Land uses often associated with sensitive receptors generally include residences, schools, libraries, hospitals, and passive recreational areas. Sensitive noise receptors may also include threatened or endangered noise sensitive biological species, although many jurisdictions have not adopted noise standards for wildlife areas. Noise sensitive land uses are typically given special attention in order to achieve protection from excessive noise. Sensitivity is a function of noise exposure (in terms of both exposure duration and insulation from noise) and the types of activities involved. In the vicinity of the project site, sensitive land uses include existing single-family residential uses east of the project site, along Kearney Street, directly behind the project site. EXISTING GENERAL AMBIENT NOISE LEVELS The existing noise environment in the project area is defined primarily by the local roadway network including San Pablo Avenue located adjacent to the project site. To quantify the existing ambient noise environment in the project vicinity, j.c. brennan & associates Inc. conducted short-term noise level measurements at two locations around the project site. A continuous noise measurement site was also conducted on the site to determine the day/night distribution of traffic on San Pablo Boulevard. Noise measurement locations are shown on Figure 2. A summary of the noise level measurement survey results are provided in Table 2. Appendix B contains the complete results of the noise monitoring. The sound level meters were programmed to record the maximum, median, and average noise levels at each site during the survey. The maximum value, denoted L max, represents the highest noise level measured. The average value, denoted L eq, represents the energy average of all of the noise received by the sound level meter microphone during the monitoring period. The median value, denoted L 50, represents the sound level exceeded 50 percent of the time during the monitoring period. Larson Davis Laboratories (LDL) Models 820 and 824 precision integrating sound level meters were used for the ambient noise level measurement survey. The meters were calibrated before and after use with an LDL Model CAL200 acoustical calibrator to ensure the accuracy of the measurements. The equipment used meets all pertinent specifications of the American National Standards Institute for Type 1 sound level meters (ANSI S1.4). Page 7 of 22

9 Table 2 Summary of Existing Background Noise Measurement Data Average Measured Hourly Noise Levels, dba Daytime (7:00 am - 10:00 pm) Nighttime (10:00 pm 7:00 am) Site Location Date Ldn Continuous 24-hour Noise Measurement Site A feet from San Pablo Avenue Centerline 1/5/17-1/6/17 Leq L50 Lmax Leq L50 Lmax Short-term Noise Measurement Sites Location Ldn Leq L50 Lmax Time 200 feet from San Pablo Avenue Centerline 35 feet from Lincoln Avenue Centerline Source: /05/ :19 P.M. N/A 01/06/ :36 A.M. 01/05/ :40 P.M. N/A 01/06/ :55 A.M. BART NOISE LEVELS The Bay Area Rapid Transit (BART) tracks are located approximately 700 feet east of the project site. During visits to the project site BART trains were audible but did not substantially influence the ambient noise environment on the project site. EXISTING AND FUTURE TRAFFIC NOISE ENVIRONMENT Off-Site Traffic Noise Impact Assessment Methodology To assess noise impacts due to project-related traffic increases on the local roadway network, traffic noise levels are predicted at sensitive receptors for existing and future, project and noproject conditions. Existing and future noise levels due to traffic are calculated using the Federal Highway Administration Highway Traffic Noise Prediction Model (FHWA RD ). The model is based upon the Calveno reference noise factors for automobiles, medium trucks and heavy trucks, with consideration given to vehicle volume, speed, roadway configuration, distance to the receiver, and the acoustical characteristics of the site. Page 8 of 22

10 The FHWA model was developed to predict hourly L eq values for free-flowing traffic conditions. To predict traffic noise levels in terms of L dn, it is necessary to adjust the input volume to account for the day/night distribution of traffic. Project trip generation volumes were provided by the project traffic engineer (Fehr & Peers, January 2017), truck usage and vehicle speeds on the local area roadways were estimated from field observations. Existing and future (2040) traffic volumes for San Pablo Avenue were obtained from the traffic study prepared for the San Pablo Specific Plan project DEIR (June, 2014). The predicted increases in traffic noise levels on the local roadway network for existing and future (2040) conditions which would result from the project are provided in terms of L dn. Traffic noise levels are predicted at the sensitive receptors located at the closest typical setback distance along each project-area roadway segment. In some locations sensitive receptors may not receive full shielding from noise barriers, or may be located at distances which vary from the assumed calculation distance. It should be noted that the traffic generated by the proposed project was considered along with the traffic generated by the San Pablo and San Pablo development projects which are currently in the permitting process. Based on the traffic study prepared for the project, traffic generated from all three projects would result in 19 AM and 29 PM peak hour trips. Predicted Exterior Traffic Noise Levels Operation of the proposed project would result in an increase in ADT volumes on the local roadway network and consequently, an increase in noise levels from traffic sources along affected segments. To examine the affect of project-generated traffic increases, traffic noise levels associated with the proposed project were calculated for roadway segments in the project study area using the FHWA model. Traffic noise levels were modeled under existing and future (2040) conditions with and without the proposed project and the two above-listed San Pablo residential projects. Table 3 summarizes the modeled traffic noise levels at the nearest sensitive receptors along each roadway segment in the Project area. Appendix C provides the complete inputs and results of the FHWA traffic modeling. Page 9 of 22

11 TABLE 3: PREDICTED TRAFFIC NOISE LEVEL AND PROJECT-RELATED TRAFFIC NOISE LEVEL INCREASES Roadway San Pablo Avenue Segment Central Ave. to Stockton Ave. Predicted Exterior Noise Level ( dba Closest Sensitive Receptors 1 st Floor Outdoor Activity Areas Existing No Project Existing + Project Change Future No Project Future + Project Change Source:, FHWA RD Traffic Noise Prediction Model, Caltrans, and Fehr & Peers Based upon the Table 3 data, the proposed project, and the two above-listed San Pablo residential projects, are predicted to result in an increase in traffic noise levels of 0.1 dba. This is not a perceptible difference. EVALUATION OF FUTURE TRANSPORTATION NOISE SOURCES ON THE PROJECT SITE On-Site Traffic Noise Prediction Methodology, utilizes the Federal Highway Administration (FHWA) Highway Traffic Noise Prediction Model (FHWA RD ) for the prediction of traffic noise levels. The model is based upon the CALVENO noise emission factors for automobiles, medium trucks and heavy trucks, with consideration given to vehicle volume, speed, roadway configuration, distance to the receiver, and the acoustical characteristics of the site. Based upon the Table 3 data, future + Project traffic noise levels for San Pablo Avenue are predicted to be 64.2 dba L dn. This noise level is based upon a distance of 160 feet, based upon the input data shown in Appendix C. Based upon the proposed setback distance to the project building, traffic noise levels have been calculated and are shown in Table 4. TABLE 4: TRAFFIC NOISE LEVELS ON PROJECT SITE Location Distance Predicted Traffic Noise Level, Ldn Building 1 Exterior dba It should be noted that average measured maximum (L max ) noise levels were found to be dba higher than the measured L dn noise level on the project site, as shown in Table 2. Therefore, the proposed Building 1 exterior would be exposed to typical maximum noise levels of dba L max. Page 10 of 22

12 EVALUATION OF PROJECT-GENERATED NON-TRANSPORTATION NOISE SOURCES The primary non-transportation noise sources associated with the proposed project are on-site parking lot circulation and heating ventilation and air-conditioning (HVAC) equipment. Mechanical Equipment Noise Based upon similar projects, it is assumed that the proposed project buildings will include rooftop mechanical equipment consisting of 21 individual condensers located in the proposed rooftop mechanical well, one for each proposed unit. Typical rooftop condensers for residential use would be expected to have a sound power rating of approximately 75 dba. The total sound power level assuming simultaneous operation of all 21 units would be 88 dba. Based upon the project site plan, the center of the mechanical rooftop well would be located approximately 70 feet from the nearest residential property line to the east. Based upon this distance and screening due to the proposed rooftop, HVAC noise levels are predicted to be 38 dba Leq. Appendix D shows the inputs and results of the noise barrier calculation used to estimate the shielding of HVAC equipment. Construction Noise Environment During the construction of the proposed project, including roads, water and sewer lines, and related infrastructure, noise from construction activities would temporarily add to the noise environment in the project vicinity. As shown in Table 5, activities involved in construction would generate maximum noise levels ranging from 76 to 90 db at a distance of 50 feet. TABLE 5: CONSTRUCTION EQUIPMENT NOISE Type of Equipment Maximum Level, dba at 50 feet Auger Drill Rig 84 Backhoe 78 Compactor 83 Compressor (air) 78 Concrete Saw 90 Dozer 82 Dump Truck 76 Excavator 81 Generator 81 Jackhammer 89 Pneumatic Tools 85 Source: Roadway Construction Noise Model User s Guide. Federal Highway Administration. FHWA-HEP January Page 11 of 22

13 Construction Vibration Environment The primary vibration-generating activities associated with the proposed project would occur during construction when activities such as grading, utilities placement, and parking lot construction occur. Table 6 shows the typical vibration levels produced by construction equipment. TABLE 6: VIBRATION LEVELS FOR VARIOUS CONSTRUCTION EQUIPMENT Type of Equipment Peak Particle Velocity at 25 feet (inches/second) Peak Particle Velocity at 50 feet (inches/second) Peak Particle Velocity at 100 feet (inches/second) Large Bulldozer Loaded Trucks Small Bulldozer Auger/drill Rigs Jackhammer Vibratory Hammer Vibratory Compactor/roller Source: Transit Noise and Vibration Impact Assessment Guidelines. Federal Transit Administration. May REGULATORY CONTEXT FEDERAL There are no federal regulations related to noise that apply to the Proposed Project. STATE There are no state regulations related to noise that apply to the Proposed Project. LOCAL City of El Cerrito General Plan The City of El Cerrito General Plan Noise Element establishes goals, policies and criteria for determining land use compatibility with major noise sources within the community. The following provides the applicable goals, policies and criteria for evaluating the feasibility and potential noise impacts associated with the proposed project. Page 12 of 22

14 Goal H3 - New development complies with the noise standards established in the General Plan, all new noise sources are within acceptable standards, and existing objectionable noise sources are reduced or eliminated. Policy H3.1 Noise Levels in New Residential Projects. New residential development projects shall meet acceptable exterior noise level standards. The "normally acceptable" noise standards for new land uses are established in Table 7-1 [Table 7], Land Use Compatibility for Community Exterior Noise Environments, which shall be modified by Policies H3.2 through H3.12, below. Policy H3.2 Outdoor Noise Levels. The goal for maximum outdoor noise levels in residential areas is an Ldn of 60 db. This level is a requirement to guide the design and location of future development and is a goal for the reduction of noise in existing development. However, 60 Ldn is a goal that cannot necessarily be reached in all residential areas within the realm of economic or aesthetic feasibility. This goal will be applied where outdoor use is a major consideration (e.g., backyards in single-family housing developments and recreation areas in multi-family housing projects). The outdoor standard will not normally be applied to the small decks associated with apartments and condominiums but these will be evaluated on a case-by-case basis. Where the city determines that providing an Ldn of 60 db or lower outdoors is not feasible, the outdoor goal may be increased to an Ldn of 65 db at the discretion of the Planning Commission. Policy H3.3 Indoor Noise Levels. The indoor noise level as required by the State of California Noise Insulation Standards must not exceed an Ldn of 45 db in new housing units. Policy H3.4 Indoor Instantaneous Noise Levels. Interior noise levels in new singlefamily and multi-family residential units exposed to an Ldn of 60 db or greater should be limited to a maximum instantaneous noise level in the bedrooms of 50 dba. Maximum instantaneous noise levels in other rooms should not exceed 55 db. The typical repetitive maximum instantaneous noise level at each site would be determined by monitor. Examples would include truck passbys on busy streets, BART passbys and train warning whistles. Policy H3.5 Impacts of BART Noise. If the noise source is BART, then the outdoor noise exposure criterion should be 70 Ldn for future development, recognizing that BART noise is characterized by relatively few loud events. Policy H3.6 New Commercial, Industrial and Office Noise Standards. Appropriate interior noise levels in commercial, industrial, and office buildings are a function of the use of space and shall be evaluated on a case-by-case basis. Interior noise levels in offices generally should be maintained at 45 Leq (hourly average) or less. Policy H3.7 Areas Below Desired Noise Standards. These guidelines are not intended to be applied reciprocally. In other words, if an area currently is below the desired Page 13 of 22

15 noise standards, an increase in noise up to the maximum should not necessarily be allowed. The impact of a proposed project on an existing land use should be evaluated in terms of the increase in existing noise levels and potential for adverse community impact, regardless [sic] Policy H3.8 Non-Transportation Related Noise Sources. For non-transportation related noise sources, noise levels outdoors should not exceed the limits in the table above. Interior noise levels shall be 15 decibels lower than those shown in the table Policy H3.9 Noise Environment in Existing Residential Areas. Protect the noise environment in existing residential areas. In general, the City will require the evaluation of mitigation measures for projects under the following circumstances: 1. The project would cause the Ldn to increase 3 db(a) or more. 2. Any increase would result in an Ldn greater than 60 db(a). 3. The Ldn already exceeds 60 db(a). 4. The project has the potential to generate significant adverse community response. Policy H3.10 Mitigating the Effects of Noise on Adjacent Properties. Require proposals to reduce noise impacts on adjacent properties by incorporating appropriate measures into the project. Policy H3.11 Commercial or Industrial Source Noise. Noise created by commercial or industrial sources associated with new projects or developments shall be controlled so as not to exceed the noise level standards set forth in the table below (Maximum Allowable Noise Exposure for Stationary Noise Sources), as measured at any affected residential land use. Policy H3.12 New Noise Reducing Technologies. Support and employ new noise reducing technologies in the development and maintenance of local and regional infrastructure. Page 14 of 22

16 TABLE 7: (TABLE 7-1 OF THE CITY OF EL CERRITO GENERAL PLAN NOISE ELEMENT) MAXIMUM ALLOWABLE NOISE EXPOSURE TRANSPORTATION NOISE SOURCES Page 15 of 22

17 TABLE 8: MAXIMUM ALLOWABLE NOISE EXPOSURE FOR STATIONARY NOISE SOURCES IN THE CITY OF EL CERRITO 1 Noise Level Descriptor Daytime 5 (7 am - 10 pm) Nighttime 2,5 (10 pm - 7 am) Hourly Leq, db Maximum Level, db Maximum Level, db Impulsive Noise As determined at the property line of the receiving land use. When determining the effectiveness of noise mitigation measures, the standards may be applied on the receptor side of noise barriers or other property line noise mitigation measures. 2. Applies only where the receiving land use operates or is occupied during nighttime hours. 3. Sound level measurements shall be made with "slow" meter response. 4. Sound level measurements shall be made with "fast" meter response. 5. Allowable levels shall be raised to the ambient noise levels where the ambient levels exceed the allowable levels. Allowable levels shall be reduced 5 db if the ambient hourly Leq is at [sic] Source: City of El Cerrito General Plan, 1999 Criteria for Acceptable Vibration Vibration is like noise in that it involves a source, a transmission path, and a receiver. While vibration is related to noise, it differs in that in that noise is generally considered to be pressure waves transmitted through air, whereas vibration usually consists of the excitation of a structure or surface. As with noise, vibration consists of an amplitude and frequency. A person s perception to the vibration will depend on their individual sensitivity to vibration, as well as the amplitude and frequency of the source and the response of the system which is vibrating. Vibration can be measured in terms of acceleration, velocity, or displacement. A common practice is to monitor vibration measures in terms of peak particle velocities in inches per second. Standards pertaining to perception as well as damage to structures have been developed for vibration levels defined in terms of peak particle velocities. Human and structural response to different vibration levels is influenced by a number of factors, including ground type, distance between source and receptor, duration, and the number of perceived vibration events. Table 9, which was developed by Caltrans, shows the vibration levels which would normally be required to result in damage to structures. The vibration levels are presented in terms of peak particle velocity in inches per second. Table 9 indicates that the threshold for architectural damage to structures is 0.20 in/sec p.p.v. and continuous vibrations of 0.10 in/sec p.p.v., or greater, would likely cause annoyance to sensitive receptors. Page 16 of 22

18 Peak Particle Velocity mm/second TABLE 9: Effects of Vibration on People and Buildings in/second Human Reaction Threshold of perception; possibility of intrusion Vibrations readily perceptible Level at which continuous vibrations begin to annoy people Vibrations annoying to people in buildings (this agrees with the levels established for people standing on bridges and subjected to relative short periods of vibrations) Vibrations considered unpleasant by people subjected to continuous vibrations and unacceptable to some people walking on bridges Effect on Buildings Vibrations unlikely to cause damage of any type Recommended upper level of the vibration to which ruins and ancient monuments should be subjected Virtually no risk of architectural damage to normal buildings Threshold at which there is a risk of architectural damage to normal dwelling - houses with plastered walls and ceilings. Special types of finish such as lining of walls, flexible ceiling treatment, etc., would minimize architectural damage Vibrations at a greater level than normally expected from traffic, but would cause architectural damage and possibly minor structural damage Source: Transportation Related Earthborne Vibrations. Caltrans. TAV R9601. February 20, Page 17 of 22

19 EVALUATION OF POJECT NOISE/VIBRATION IMPACTS IMPACT 1: WOULD THE PROJECT RESULT IN EXPOSURE OF PERSONS TO OR GENERATION OF NOISE LEVELS IN EXCESS OF STANDARDS ESTABLISHED IN THE LOCAL GENERAL PLAN OR NOISE ORDINANCE, OR APPLICABLE STANDARDS OF OTHER AGENCIES? As shown in Table 3, traffic from the proposed project is not predicted to cause exterior noise levels to exceed the City s 60 dba L dn exterior noise level standard at any existing residential areas where no-project noise levels are less than 60 dba L dn. Operation of the project is predicted to generate exterior HVAC noise levels of 38 dba L eq, or less, at the nearest sensitive receptors. These noise levels would comply with the City of El Cerrito 45 dba L eq nighttime exterior noise level standard. As shown in Table 4, traffic from San Pablo Avenue is predicted to be 71 dba L dn at the building façade of the proposed project. Based upon a typical 25 db exterior-to-interior noise level reduction achieved by modern building construction, an interior noise level of 46 dba L dn would be expected. This would exceed the City s 45 db L dn interior noise level standard. Additionally, the City applies an interior maximum noise level standard of 50 dba L max to bedrooms and 55 dba L max to other occupied rooms. Based upon a typical 25 db noise level reduction and the predicted exterior noise level range of dba L max, maximum interior noise levels are predicted to range between dba L max. Therefore, interior noise control measures would be required to achieve compliance with the City s interior noise level standards. Interior noise control measures are outlined below. The complete inputs and results of the interior noise control calculations are provided in Appendix E. Noise Control Measure for Impact 1: Noise Control Measure 1: The following interior noise reduction measures should be included for all west facing (facing San Pablo Avenue) units: Interior Noise Control Measures: o o o Living room and bedroom windows shall have a sound transmission class (STC) rating of 38. Exterior finish shall be three-coat stucco or system with equivalent weight per square foot; Interior gypsum at exterior walls shall be 5/8 Type X or Type C hung on resilient channel (RC); o Ceiling gypsum shall be 5/8 type X or Type C; Page 18 of 22

20 o Mechanical ventilation shall be installed in all residential uses to allow residents to keep doors and windows closed, as desired for acoustical isolation. As an alternative to the above-listed interior noise control measures, the applicant may provide a detailed analysis of interior noise control measures once building plans become available. The analysis should be prepared by a qualified noise control engineer and shall outline the specific measures required to meet the City s 45 db L dn and dba L max, interior noise level standards. IMPACT 2: WOULD THE PROJECT RESULT IN EXPOSURE OF PERSONS TO OR GENERATION OF EXCESSIVE GROUNDBORNE VIBRATION OR GROUNDBORNE NOISE LEVELS? Construction vibration impacts include human annoyance and building structural damage. Human annoyance occurs when construction vibration rises significantly above the threshold of perception. Building damage can take the form of cosmetic or structural. The Table 6 data indicate that construction vibration levels anticipated for the project are less than the 0.2 in/sec p.p.v. threshold of damage to buildings and less than the 0.1 in/sec threshold of annoyance criteria at distances of 50 feet. Sensitive receptors which could be impacted by construction related vibrations, especially vibratory compactors/rollers, are located approximately 50 feet, or further, from typical construction activities. At these distances construction vibrations are not predicted to exceed acceptable levels. Additionally, construction activities would be temporary in nature and would likely occur during normal daytime working hours. Therefore, no additional vibration control measures would be required. Page 19 of 22

21 IMPACT 3: Traffic Noise Increases WOULD THE PROJECT RESULT IN A SUBSTANTIAL PERMANENT INCREASE IN AMBIENT NOISE LEVELS IN THE PROJECT VICINITY ABOVE LEVELS EXISTING WITHOUT THE PROJECT? As shown in Table 3, the proposed project is not predicted to increase traffic noise levels on San Pablo Avenue more than 0.1 dba. Therefore, no additional noise control measures would be required. Non-Transportation Noise Increases The proposed project is predicted to generate non-transportation noise of 38 dba L eq at the nearest residential receptors. Ambient noise measurements indicate that existing nighttime noise levels are approximately 56 dba L eq. Therefore, operation of the proposed project is not predicted to generate noise levels exceeding existing ambient noise levels and no additional noise control measures would be required. IMPACT 4: WOULD THE PROJECT RESULT IN ASUBSTANTIAL TEMPORARY OR PERIODIC INCREASE IN AMBIENT NOISE LEVELS IN THE PROJECT VICINITY ABOVE LEVELS EXISTING WITHOUT THE PROJECT? The new development and infrastructure improvements associated with the project will require construction activities. These activities include the use of heavy equipment and impact tools. Table 5 provides a list of the types of equipment which may be associated with construction activities and the associated noise levels. Activities involved in project construction would typically generate maximum noise levels ranging from 76 to 90 db at a distance of 50 feet. The nearest residential receptors would be located 50 feet, or further, from typical construction activities. It should be noted that construction noise was noted to be a significant unavoidable impact in the San Pablo Avenue Specific Plan. The following are mitigation measures outlined in the Specific Plan: Mitigation Construction equipment shall be well-maintained and used judiciously to be as quiet as practical. The following measures, when applicable, are recommended to reduce noise from construction activities: Equip all internal combustion engine-driven equipment with mufflers that are in good condition and appropriate for the equipment. Utilize quiet models of air compressors and other stationary noise sources where technology exists. Page 20 of 22

22 Locate stationary noise-generating equipment as far as feasible from sensitive receptors when sensitive receptors adjoin or are near a construction area. Prohibit unnecessary idling of internal combustion engines. Pre-drill foundation pile holes to minimize the number of impacts required to seat the pile. Construct solid plywood fences around construction sites adjacent to operational business, residences, or noise-sensitive land uses. A temporary noise control blanket barrier could be erected, if necessary, along building facades facing construction sites. This mitigation would only be necessary if conflicts occurred which were irresolvable by proper scheduling. Noise control blanket barriers can be rented and quickly erected. Route construction-related traffic along major roadways and as far as feasible from sensitive receptors. Ensure that construction activities (including the loading and unloading of materials and truck movements) are limited to the hours of 7:00 AM to 7:00 PM on weekdays and between the hours of 9:00 AM and 8:00 PM on weekends and holidays. Ensure that excavating, grading, and filling activities (including warming of equipment motors) are limited to between the hours of 7:00 AM to 7:00 PM on weekdays and between the hours of 9:00 AM and 8:00 PM on weekends and holidays. Businesses, residences, or noise-sensitive land uses adjacent to construction sites shall be notified of the construction schedule in writing. Designate a construction liaison who would be responsible for responding to any local complaints about construction noise. The liaison would determine the cause of the noise complaints (e.g., starting too early, bad muffler, etc.) and institute reasonable measures to correct the problem. Conspicuously post a telephone number for the liaison at the construction site. The proposed project would not be expected to generate construction noise greater than that anticipated under the San Pablo Avenue Specific Plan EIR. Therefore, no additional noise control measures are required. Page 21 of 22

23 IMPACT 5: FOR A PROJECT LOCATED WITHIN 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? There are no public airports in the project vicinity. Therefore, this impact is not applicable to the proposed project. IMPACT 6: FOR A PROJECT WITHIN THE VICINITY OF A PRIVATE AIRSTRIP, WOULD THE PROJECT EXPOSE PEOPLE RESIDING OR WORKING IN THE PROJECT AREA TO EXCESSIVE NOISE LEVELS? There are no private airstrips in the project vicinity. Therefore, this impact is not applicable to the proposed project. Page 22 of 22

24 Appendix A Acoustical Terminology Acoustics Ambient Noise Attenuation A-Weighting Decibel or db CNEL Frequency Ldn Leq Lmax L(n) Loudness Noise NRC Peak Noise RT60 Sabin SEL STC Threshold of Hearing Threshold of Pain Impulsive Simple Tone The science of sound. The distinctive acoustical characteristics of a given space consisting of all noise sources audible at that location. In many cases, the term ambient is used to describe an existing or pre-project condition such as the setting in an environmental noise study. The reduction of an acoustic signal. A frequency-response adjustment of a sound level meter that conditions the output signal to approximate human response. Fundamental unit of sound, A Bell is defined as the logarithm of the ratio of the sound pressure squared over the reference pressure squared. A Decibel is one-tenth of a Bell. Community Noise Equivalent Level. Defined as the 24-hour average noise level with noise occurring during evening hours (7-10 p.m.) weighted by a factor of three and nighttime hours weighted by a factor of 10 prior to averaging. The measure of the rapidity of alterations of a periodic signal, expressed in cycles per second or hertz (Hz). Day/Night Average Sound Level. Similar to CNEL but with no evening weighting. Equivalent or energy-averaged sound level. The highest root-mean-square (RMS) sound level measured over a given period of time. The sound level exceeded a described percentile over a measurement period. For instance, an hourly L50 is the sound level exceeded 50% of the time during the one hour period. A subjective term for the sensation of the magnitude of sound. Unwanted sound. Noise Reduction Coefficient. NRC is a single-number rating of the sound-absorption of a material equal to the arithmetic mean of the sound-absorption coefficients in the 250, 500, 1000, and 2,000 Hz octave frequency bands rounded to the nearest multiple of It is a representation of the amount of sound energy absorbed upon striking a particular surface. An NRC of 0 indicates perfect reflection; an NRC of 1 indicates perfect absorption. The level corresponding to the highest (not RMS) sound pressure measured over a given period of time. This term is often confused with the AMaximum@ level, which is the highest RMS level. The time it takes reverberant sound to decay by 60 db once the source has been removed. The unit of sound absorption. One square foot of material absorbing 100% of incident sound has an absorption of 1 Sabin. Sound Exposure Level. SEL is s rating, in decibels, of a discrete event, such as an aircraft flyover or train passby, that compresses the total sound energy into a one-second event. Sound Transmission Class. STC is an integer rating of how well a building partition attenuates airborne sound. It is widely used to rate interior partitions, ceilings/floors, doors, windows and exterior wall configurations. The lowest sound that can be perceived by the human auditory system, generally considered to be 0 db for persons with perfect hearing. Approximately 120 db above the threshold of hearing. Sound of short duration, usually less than one second, with an abrupt onset and rapid decay. Any sound which can be judged as audible as a single pitch or set of single pitches.

25 Appendix B San Pablo Ave 24hr Continuous Noise Monitoring - Site A January 5th - 6th, 2017 Hour Leq Lmax L50 L90 Statistical Summary 12:00: Daytime (7 a.m p.m.) Nighttime (10 p.m. - 7 a.m.) 13:00: High Low Average High Low Average 14:00: Leq (Average) :00: Lmax (Maximum) :00: L50 (Median) :00: L90 (Background) :00: :00: Computed Ldn, db 64 20:00: % Daytime Energy 90% 21:00: % Nighttime Energy 10% 22:00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00:

26 Appendix B San Pablo Ave 24hr Continuous Noise Monitoring - Site A January 5th - 6th, Sound Level, db PM 4 PM 8 PM 12 AM 4 AM 8 AM Hour of Day Ldn = 64 db Leq Lmax L50 L90

27 Appendix C FHWA-RD Highway Traffic Noise Prediction Model Data Input Sheet Project #: Description: Ldn/CNEL: Traffic Conditions Ldn Hard/Soft: Hard % Med. % Hvy. Segment Roadway Name Segment Description ADT Day % Eve % Night % Trucks Trucks Speed Distance (db) Existing San Pablo Avenue Central to Stockton 19, Existing + Project San Pablo Avenue Central to Stockton 19, Future 2040 San Pablo Avenue Central to Stockton 24, Future Project San Pablo Avenue Central to Stockton 24,

28 Appendix C FHWA-RD Highway Traffic Noise Prediction Model Predicted Levels Project #: Description: Traffic Conditions Ldn/CNEL: Ldn Hard/Soft: Hard Segment Roadway Name Segment Description Autos Medium Trucks Heavy Trucks Total Existing San Pablo Avenue Central to Stockton Existing + Project San Pablo Avenue Central to Stockton Future 2040 San Pablo Avenue Central to Stockton Future Project San Pablo Avenue Central to Stockton

29 Appendix D Barrier Insertion Loss Calculation Project Information: Job Number: Project Name: San Pable Avenue Residential Location(s): Nearest Residential to East Noise Level Data: Site Geometry: Source Description: Rooftop HVAC Source Noise Level, dba: 53 Source Frequency (Hz): 1000 Source Height (ft): 47 Receiver Description: Nearest Backyard Source to Barrier Distance (C 1 ): 12 Barrier to Receiver Distance (C 2 ): 58 Pad/Ground Elevation at Receiver: 0 Receiver Elevation 1 : 5 Base of Barrier Elevation: 49.5 Starting Barrier Height 0 Barrier Effectiveness: Top of Barrier Elevation (ft) Barrier Height (ft) Insertion Loss, db Noise Level, db Barrier Breaks Line of Site to Source? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Notes: 1.Standard receiver elevation is five feet above grade/pad elevations at the receiver location(s)

30 Appendix E Building Facade Noise Reduction Worksheet San Pablo Residential Plans Dated: October 14, 2016 Analysis Date: 2/7/2017 0:00 Room Description: Living Room Parallel Panel Size, ft 2 : 220 Perpendicular Panel Size, ft 2 : 120 Parallel Exterior level, db: 85 Perpendicular Exterior level, db: 85 Correction Factor, db: 5 Noise Source Information: Arterial Traffic - Tice Blvd. Contra Costa Parallel, db Arterial Traffic - Tice Blvd. Contra Costa Perpendicular, db One-Third Octave Band Center Frequency (Hz) Material Area(ft 2 ) K 1.25K 1.6K 2K 2.5K 3.15K 4K Gyp Board Glass Linoleum, rubber, or asphalt tile on concrete Soft Furnishings Absorption Parallel, db: Absorption Perpendicular, db: Wall - Stucco wall with RC Window - Quiet Home STC Wall - Stucco wall with RC Window - Quiet Home STC Composite TL - Parallel, db: Composite TL - Perpendicular, db: Absorption Parallel, db: Absorption Perpendicular, db: Safety Factor, db: Interior Level - Parallel, db: Interior Level - Perpendicular, db: Sound Absorption Data: Transmission Loss Information: Parallel Façade Transmission Loss Information: Perpendicular Façade Summary Parallel Outside Level, db: 85 Perpendicular Outside Level, db: 85 Noise Reduction, db: 31 Parallel Interior Level, db: 51 Perpendicular Interior Level, db: 51 Total Interior Noise Level, db: 54

31 Appendix E Building Facade Noise Reduction Worksheet San Pablo Residential Plans Dated: October 14, 2016 Analysis Date: 2/7/2017 0:00 Room Description: Bedroom Parallel Panel Size, ft 2 : 110 Perpendicular Panel Size, ft 2 : 120 Parallel Exterior level, db: 85 Perpendicular Exterior level, db: 85 Correction Factor, db: 5 Noise Source Information: Arterial Traffic - Tice Blvd. Contra Costa Parallel, db Arterial Traffic - Tice Blvd. Contra Costa Perpendicular, db One-Third Octave Band Center Frequency (Hz) Material Area(ft 2 ) K 1.25K 1.6K 2K 2.5K 3.15K 4K Sound Absorption Data: Gyp Board Glass Carpet, latex backing on foam pad Soft Furnishings Absorption Parallel, db: Absorption Perpendicular, db: Wall - Stucco wall with RC Window - Quiet Home STC Wall - Stucco wall with RC Composite TL - Parallel, db: Composite TL - Perpendicular, db: Absorption Parallel, db: Absorption Perpendicular, db: Safety Factor, db: Interior Level - Parallel, db: Interior Level - Perpendicular, db: Transmission Loss Information: Parallel Façade Transmission Loss Information: Perpendicular Façade Summary Parallel Outside Level, db: 85 Perpendicular Outside Level, db: 85 Noise Reduction, db: 36 Parallel Interior Level, db: 49 Perpendicular Interior Level, db: 37 Total Interior Noise Level, db: 49