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EXHIBIT 1-B: SITE PLAN
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2 FUNDAMENTALS Noise is simply defined as "unwanted sound." Sound becomes unwanted when it interferes with normal activities, when it causes actual physical harm or when it has adverse effects on health. Noise is measured on a logarithmic scale of sound pressure level known as a decibel (dB). A-weighted decibels (dBA) approximate the subjective response of the human ear to broad frequency noise source by discriminating against very low and very high frequencies of the audible spectrum. They are adjusted to reflect only those frequencies which are audible to the human ear. Exhibit 2-A presents a summary of the typical noise levels and their subjective loudness and effects that are described in more detail below. EXHIBIT 2-A: TYPICAL NOISE LEVELS Source: Environmental Protection Agency Office of Noise Abatement and Control, Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety (EPA/ONAC 550/9-74-004) March 1974. 2.1 RANGE OF NOISE Since the range of intensities that the human ear can detect is so large, the scale frequently used to measure intensity is a scale based on multiples of 10, the logarithmic scale. The scale for measuring intensity is the decibel scale. Each interval of 10 decibels indicates a sound energy ten times greater than before, which is perceived by the human ear as being roughly twice as loud. (3) The most common sounds vary between 40 dBA (very quiet) to 100 dBA (very loud). Normal conversation at three feet is roughly at 60 dBA, while loud jet engine noises equate to 110 dBA
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at approximately 100 feet, which can cause serious discomfort. (4) Another important aspect of noise is the duration of the sound and the way it is described and distributed in time. 2.2 NOISE DESCRIPTORS Environmental noise descriptors are generally based on averages, rather than instantaneous, noise levels. The most used figure is the equivalent level (Leq). Equivalent sound levels are not measured directly but are calculated from sound pressure levels typically measured in A-weighted decibels (dBA). The equivalent sound level (Leq) represents a steady state sound level containing the same total energy as a time varying signal over a given sample period (typically one hour) and is commonly used to describe the “average” noise levels within the environment. Peak hour or average noise levels, while useful, do not completely describe a given noise environment. Noise levels lower than peak hour may be disturbing if they occur during times when quiet is most desirable, namely evening and nighttime (sleeping) hours. To account for this, the Community Noise Equivalent Level (CNEL), representing a composite 24-hour noise level is utilized. The CNEL is the weighted average of the intensity of a sound, with corrections for time of day, and averaged over 24 hours. The time-of-day corrections require the addition of 5 decibels to dBA Leq sound levels in the evening from 7:00 p.m. to 10:00 p.m., and the addition of 10 decibels to dBA Leq sound levels at night between 10:00 p.m. and 7:00 a.m. These additions are made to account for the noise sensitive time periods during the evening and night hours when sound appears louder. CNEL does not represent the actual sound level heard at any time, but rather represents the total sound exposure. The City of Riverside relies on the 24-hour CNEL level to assess land use compatibility with transportation related noise sources. 2.3 SOUND PROPAGATION When sound propagates over a distance, it changes in level and frequency content. The way noise reduces with distance depends on the following factors. 2.3.1 GEOMETRIC SPREADING Sound from a localized source (i.e., a stationary point source) propagates uniformly outward in a spherical pattern. The sound level attenuates (or decreases) at a rate of 6 dB for each doubling of distance from a point source. Highways consist of several localized noise sources on a defined path and hence can be treated as a line source, which approximates the effect of several point sources. Noise from a line source propagates outward in a cylindrical pattern, often referred to as cylindrical spreading. Sound levels attenuate at a rate of 3 dB for each doubling of distance from a line source. (3) 2.3.2 GROUND ABSORPTION The propagation path of noise from a highway to a receiver is usually very close to the ground. Noise attenuation from ground absorption and reflective wave canceling adds to the attenuation associated with geometric spreading. Traditionally, the excess attenuation has also been expressed in terms of attenuation per doubling of distance. This approximation is usually Dauchy Avenue Noise Impact Analysis
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sufficiently accurate for distances of less than 200 ft. For acoustically hard sites (i.e., sites with a reflective surface between the source and the receiver, such as a parking lot or body of water), no excess ground attenuation is assumed. For acoustically absorptive or soft sites (i.e., those sites with an absorptive ground surface between the source and the receiver such as soft dirt, grass, or scattered bushes and trees), an excess ground attenuation value of 1.5 dB per doubling of distance is normally assumed. When added to the cylindrical spreading, the excess ground attenuation results in an overall drop-off rate of 4.5 dB per doubling of distance from a line source. (2) 2.3.3 ATMOSPHERIC EFFECTS Receivers located downwind from a source can be exposed to increased noise levels relative to calm conditions, whereas locations upwind can have lowered noise levels. Sound levels can be increased at large distances (e.g., more than 500 feet) due to atmospheric temperature inversion (i.e., increasing temperature with elevation). Other factors such as air temperature, humidity, and turbulence can also have significant effects. (3) 2.3.4 SHIELDING A large object or barrier in the path between a noise source and a receiver can substantially attenuate noise levels at the receiver. The amount of attenuation provided by shielding depends on the size of the object and the frequency content of the noise source. Shielding by trees and other such vegetation typically only has an “out of sight, out of mind” effect. That is, the perception of noise impact tends to decrease when vegetation blocks the line-of-sight to nearby residents. However, for vegetation to provide a substantial, or even noticeable, noise reduction, the vegetation area must be at least 15 feet in height, 100 feet wide and dense enough to completely obstruct the line-of sight between the source and the receiver. This size of vegetation may provide up to 5 dBA of noise reduction. The Federal Highway Administration (FHWA) does not consider the planting of vegetation to be a noise abatement measure (2). 2.4 NOISE CONTROL Noise control is the process of obtaining an acceptable noise environment for an observation point or receiver by controlling the noise source, transmission path, receiver, or all three. This concept is known as the source-path-receiver concept. In general, noise control measures can be applied to these three elements. 2.5 NOISE BARRIER ATTENUATION Effective noise barriers can reduce noise levels by up to 10 to 15 dBA, cutting the loudness of traffic noise in half. A noise barrier is most effective when placed close to the noise source or receiver. Noise barriers, however, do have limitations. For a noise barrier to work, it must be high enough and long enough to block the path of the noise source (2).
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2.6 LAND USE COMPATIBILITY WITH NOISE Some land uses are more tolerant of noise than others. For example, schools, hospitals, churches, and residences are more sensitive to noise intrusion than are commercial or industrial developments and related activities. As ambient noise levels affect the perceived amenity or livability of a development, so too can the mismanagement of noise impacts impair the economic health and growth potential of a community by reducing the area’s desirability as a place to live, shop and work. For this reason, land use compatibility with the noise environment is an important consideration in the planning and design process. The FHWA encourages State and Local government to regulate land development in such a way that noise-sensitive land uses are either prohibited from being located adjacent to a highway, or that the developments are planned, designed, and constructed in such a way that noise impacts are minimized (5). 2.7 COMMUNITY RESPONSE TO NOISE Community responses to noise may range from registering a complaint by telephone or letter, to initiating court action, depending upon everyone’s susceptibility to noise and personal attitudes about noise. Several factors are related to the level of community annoyance including: • Fear associated with noise producing activities; • Socio-economic status and educational level; • Perception that those affected are being unfairly treated; • Attitudes regarding the usefulness of the noise-producing activity; • Belief that the noise source can be controlled. Approximately ten percent of the population has a very low tolerance for noise and will object to any noise not of their making. Consequently, even in the quietest environment, some complaints will occur. Twenty-five percent of the population will not complain even in very severe noise environments. Thus, a variety of reactions can be expected from people exposed to any given noise environment. (6) Surveys have shown that about ten percent of the people exposed to traffic noise of 60 dBA will report being highly annoyed with the noise, and each increase of one dBA is associated with approximately two percent more people being highly annoyed. When traffic noise exceeds 60 dBA or aircraft noise exceeds 55 dBA, people may begin to complain. (6) Despite this variability in behavior on an individual level, the population can be expected to exhibit the following responses to changes in noise levels as shown on Exhibit 2-B. A change of 3 dBA is considered barely perceptible, and changes of 5 dBA are considered readily perceptible. (2) Dauchy Avenue Noise Impact Analysis
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EXHIBIT 2-B: NOISE LEVEL INCREASE PERCEPTION
2.8 VIBRATION Per the Federal Transit Administration (FTA) Transit Noise and Vibration Impact Assessment Manual (7), vibration is the periodic oscillation of a medium or object. Vibration is the periodic oscillation of a medium or object. The rumbling sound caused by the vibration of room surfaces is called structure-borne noise. Sources of ground-borne vibrations include natural phenomena (e.g., earthquakes, volcanic eruptions, sea waves, landslides) or human-made causes (e.g., explosions, machinery, traffic, trains, construction equipment). Vibration sources may be continuous, such as factory machinery, or transient, such as explosions. As is the case with airborne sound, ground-borne vibrations may be described by amplitude and frequency. There are several different methods that are used to quantify vibration. The peak particle velocity (PPV) is defined as the maximum instantaneous peak of the vibration signal. The PPV is most frequently used to describe vibration impacts to buildings but is not always suitable for evaluating human response (annoyance) because it takes some time for the human body to respond to vibration signals. Instead, the human body responds to average vibration amplitude often described as the root mean square (RMS). The RMS amplitude is defined as the average of the squared amplitude of the signal and is most frequently used to describe the effect of vibration on the human body. However, the RMS amplitude and PPV are related mathematically, and the RMS amplitude can be calculated from the PPV. The RMS amplitude is approximately 70% of the PPV (8). Typically, ground-borne vibration generated by man-made activities attenuates rapidly with distance from the source of the vibration. Sensitive receivers for vibration include structures (especially older masonry structures), people (especially residents, the elderly, and sick), and vibration-sensitive equipment and/or activities. While not universally accepted, vibration decibel notation (VdB) is used by the FTA in their guidance manual to describe vibration levels and provide a background of common vibration levels (9). As stated in the FTA guidance manual, the background vibration-velocity level in residential areas is generally 50 VdB. Ground-borne vibration is normally perceptible to humans at approximately 65 VdB. For most people, a vibration-velocity level of 75 VdB is the approximate dividing line between barely perceptible and distinctly perceptible levels. Typical outdoor sources of perceptible ground-borne vibration are construction equipment, steel-wheeled trains, and traffic on rough roads. If a roadway is smooth, the ground-borne vibration is rarely perceptible. The range of interest is from approximately 50 VdB, which is the typical background 012345678910Just PerceptibleBarely PerceptibleReadily PerceptibleTwice as Loud Noise…
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vibration-velocity level, to 100 VdB, which is the general threshold where minor damage can occur in fragile buildings. Exhibit 2-C illustrates common vibration sources and the human and structural response to ground-borne vibration. EXHIBIT 2-C: TYPICAL LEVELS OF GROUND-BORNE VIBRATION Source: Federal Transit Administration (FTA) Transit Noise Impact and Vibration Assessment Manual
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3 REGULATORY SETTING To limit population exposure to physically and/or psychologically damaging as well as intrusive noise levels, the federal government, the State of California, various county governments, and most municipalities in the state have established standards and ordinances to control noise. In most areas, automobile and truck traffic is the major source of environmental noise. Traffic activity generally produces an average sound level that remains constant with time. Air and rail traffic, and commercial and industrial activities are also major sources of noise in some areas. Federal, state, and local agencies regulate different aspects of environmental noise. Federal and state agencies generally set noise standards for mobile sources such as aircraft and motor vehicles, while regulation of stationary sources is left to local agencies. 3.1 STATE OF CALIFORNIA NOISE REQUIREMENTS The State of California regulates freeway noise, sets standards for sound transmission, provides occupational noise control criteria, identifies noise standards, and provides guidance for local land use compatibility. State law requires that each county and city adopt a General Plan that includes a Noise Element which is to be prepared per guidelines adopted by the Governor’s Office of Planning and Research. (8) The purpose of the Noise Element is to limit the exposure of the community to excessive noise levels. In addition, the California Environmental Quality Act (CEQA) requires that all known environmental effects of a project be analyzed, including environmental noise impacts. The State of California’s noise insulation standards for all residential units are codified in the California Code of Regulations (CCR), Title 24, Building Standards Administrative Code, Chapter 12, Section 1206. These noise standards are applied to new construction that contains dwelling units or sleeping units, such as residential and hotel or motel uses, in California for controlling interior noise levels resulting from exterior noise sources. For new buildings, the acceptable interior noise limit is 45 dBA CNEL in habitable rooms (11). 3.2 CITY OF RIVERSID GENERAL PLAN The City of Riverside has adopted a Noise Element of the General Plan to control and abate environmental noise, and to protect the citizens of the City of Riverside from excessive exposure to noise. In addition, the Noise Element identifies several polices to minimize the impacts of excessive noise levels throughout the community and establishes noise level compatibility criteria for different land uses. The Noise/Land Use Noise Compatibility Criteria (Figure N-10) in the City of Riverside General Plan Noise Element provides guidelines to evaluate the land use compatibility as shown on Exhibit 3-A. Figure N-10 provides the City with a planning tool to gauge the compatibility of land uses relative to existing and future exterior noise levels (9). The Noise/Land Use Noise Compatibility Criteria describes categories of compatibility and not specific noise standards. According to the noise/land use categories of compatibility, single-family residential uses are considered normally acceptable with unmitigated exterior noise levels below 60 dBA CNEL, conditionally acceptable Dauchy Avenue Noise Impact Analysis
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with noise levels below 65 dBA CNEL, normally unacceptable with noise levels below 70 dBA CNEL, and conditionally unacceptable with noise levels above 70 dBA CNEL (9). EXHIBIT 3-A: NOISE/LAND USE NOISE COMPATIBILITY CRITERIA
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3.3 CITY OF RIVERSIDE MUNICIPAL CODE As shown in Table 5.11-E, Riverside Municipal Code- Title 7 Interior and Exterior Noise Standards, the City of Riverside’s Noise Code (Title 7- Ord.6273. 1) sets internal and external noise standards for specific land uses/zoning (Sections 7.25.010 and 7.30.015). TABLE 3-1: RIVERSIDE MUNICIPAL CODE- TITLE 7 INTERIOR AND EXTERIOR NOISE STANDARDS Land Use Time Period Noise Standards (dBA) Exterior Interior Residential 7 a.m. – 10 p.m. 55 45 10 p.m. – 7 a.m. 45 35 Schools 7 a.m. – 10 p.m. -- 45 Hospitals Anytime -- 45 Office/Commercial Anytime 65 -- Industrial Anytime 70 -- Community Support Anytime 60 -- Public Recreation Facility Anytime 65 -- Non-Urban Anytime 70 -- Section 7.25.010 (A) indicates that it is unlawful for any person to cause or allow the creation of any noise which exceeds the following: 1. The exterior noise standard of the applicable land use category up to 5 dBA for a cumulative period of 30 minutes in any hour (L50); or 2. The exterior noise standard of the applicable land use category, plus 5 dBA, for a cumulative period of more than 15 minutes in any hour (L₂₅); or 3. The exterior noise standard of the applicable land use category, plus 10 dBA, for a cumulative period of more than 5 minutes in any hour (L8); or 4. The exterior noise standard of the applicable land use category, plus 15 dBA, for a cumulative period of more than 1 minute in any hour (L2). 5. The exterior noise standard for the applicable land use category, plus twenty decibels or the maximum measured ambient noise level, for any period of time (Lmax). In addition, Section 7.25.010 (B) indicates that if the existing ambient noise level already exceeds any of the exterior noise level limit categories, then the standard shall be increased in five decibel increments in each category as appropriate to encompass the ambient noise level. According to Section 7.25.010 (C), if possible, the ambient noise level shall be measured at the same location along the property line with the alleged offending noise source inoperative. If for any reason the alleged offending noise source cannot be shut down, then the ambient noise must be estimated by performing a measurement in the same general area of the source but at a sufficient distance that the offending noise is inaudible. If the measurement location is on the boundary between two different districts, the noise shall be the arithmetic mean of the two districts.
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To assess the interior noise levels for noise sensitive residential properties, Table 7.30.015 identifies interior noise standards for the daytime (7:00 a.m. to 10:00 p.m.) hours of 45 dBA L8 and 35 dBA L8 during the nighttime (10:00 p.m. to 7:00 a.m.) hours as shown on Table 3-2. TABLE 3-2: INTERIOR SOUND LEVEL LIMITS Land Use Time Period Interior Noise Level Standards (dBA)1 L8 (5 mins) L2 (1 min) Lmax (0 min) Residential Daytime 45 50 55 Nighttime 35 40 45 School While in Session 45 50 55 Hospital Anytime 45 50 55 1 The percent noise level is the level exceeded "n" percent of the time during the measurement period. L50 is the noise level exceeded 50% of the time. 2 City of Riverside Municipal Code, Title 7 Noise Control, Section 7.30.015 (A) (Appendix 3.1). "Daytime" = 7:00 a.m. to 10:00 p.m.; "Nighttime" = 10:00 p.m. to 7:00 a.m.
Section 7.30.015 (A) indicates that no person shall operate or cause to be operated, any source of sound indoors which causes the noise level, when measured inside another dwelling unit, school or hospital, to exceed: 1. The interior noise standard for the applicable land category area, up to five decibels, for a cumulative period of more than five minutes in any (L8); or 2. The interior noise standard for the applicable land use category, plus five decibels, for a cumulative period of more than one minute in any hour; (L₂); or 3. The interior noise standard for the applicable land use category, plus ten decibels or the maximum measured ambient noise level, for any period of time (Lmax). The City of Riverside Municipal Code Title 7 Noise Control section is included in Appendix 3.1. 3.5 CONSTRUCTION NOISE STANDARDS To control noise impacts associated with the construction of the proposed Project, the City of RiversideCity of Riverside has established limits to the hours of operation. Section 7.35.020 (G) of the General Noise Regulations indicates that noise sources associated with construction, repair, remodeling, or grading of any real property; provided a permit has been obtained from the City as required; and provided said activities do not take place between the hours of 7:00 p.m. and 7:00 a.m. on weekdays, between the hours of 5:00 p.m. and 8:00 a.m. on Saturdays, or at any time on Sunday or a federal holiday. Therefore, Project construction noise levels are considered exempt from municipal regulation if activities occur within the hours specified Section 7.35.020 (G); provided a permit has been obtained from the City, as required. However, neither the City of Riverside General Plan nor Municipal Code establish numeric maximum acceptable construction source noise levels at potentially affected receivers. Therefore, a numerical construction threshold based on Federal Transit Administration (FTA) Dauchy Avenue Noise Impact Analysis
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Transit Noise and Vibration Impact Assessment Manual is used for analysis of daytime construction impacts. According to the FTA, local noise ordinances are typically not very useful in evaluating construction noise. They usually relate to nuisance and hours of allowed activity, and sometimes specify limits in terms of maximum levels, but are generally not practical for assessing the impact of a construction project. Project construction noise criteria should account for the existing noise environment, the absolute noise levels during construction activities, the duration of the construction, and the adjacent land use. Due to the lack of standardized construction noise thresholds, the FTA provides guidelines that can be considered reasonable criteria for construction noise assessment. The FTA considers a daytime exterior construction noise level of 80 dBA Leq as a reasonable threshold for noise sensitive residential land use. (7 p. 179) 3.5 CONSTRUCTION VIBRATION CRITERIA Construction activity can result in varying degrees of ground-borne vibration, depending on the equipment and methods used, distance to the affected structures and soil type. Construction vibration is generally associated with pile driving and rock blasting. Other construction equipment such as air compressors, light trucks, hydraulic loaders, etc., generates little or no ground vibration. (7) To analyze vibration impacts originating from the operation and construction of the Project Dauchy Avenue, vibration-generating activities are appropriately evaluated against standards established under a City’s Municipal Code, if such standards exist. However, the City of Riverside does not identify specific vibration level limits. Therefore, for analysis purposes, the Caltrans Transportation and Construction Vibration Guidance Manual, (10 p. 38) Table 19, vibration damage are used in this noise study to assess potential temporary construction-related impacts at adjacent building locations. The construction vibration damage potential criteria include consideration of the building conditions. (4 p. 182) Table 3-2 describes the maximum acceptable transient and continuous vibration building damage potential levels by structure type and condition. The existing buildings adjacent to the Project site can best be described as “older residential structures” with a maximum acceptable continuous vibration threshold of 0.3 PPV (in/sec). TABLE 3-2: BUILDING DAMAGE VIBRATION CRITERIA Structure and Condition Maximum Transient Vibration Levels PPV (in/sec) Maximum Continuous Vibration Levels PPV (in/sec) Extremely fragile historic buildings 0.12 0.08 Fragile buildings 0.2 0.1 Historic and some old buildings 0.5 0.25 Older residential structures 0.5 0.3 New residential structures 1.0 0.5 Modern industrial/commercial buildings 2.0 0.5 Dauchy Avenue Noise Impact Analysis
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Caltrans Transportation and Construction Vibration Guidance Manual, April 2020, Tables 19, p. 38.
3.6 MARCH AIR RESERVE BASE/INLAND PORT AIRPORT LAND USE COMPATIBILITY The March Air Reserve Base/Inland Port Airport (MARB/IPA) is located approximately 3.6-miles east of the Project site. The March Air Reserve Base/Inland Port Airport Land Use Compatibility Plan (MARB/IPA LUCP) includes the policies for determining the land use compatibility of the Project. The MARB/IPA, Map MA-1, indicates that the Project site is located within Compatibility Zone D, which Table MA-1 Compatibility Zone Factors indicates is considered to have a moderate to low noise impact. (11) Further, the Project site is located outside of the 60 dBA CNEL noise level contour boundary. The MARB/IPA LUCP does not identify specific noise compatibility standards, and therefore, the City of Riverside Land Use Compatibility for Community Noise Exposure matrix, previously discussed in Section 3.3, is used to assess potential aircraft-related noise levels at the Project site. The City of Riverside guidelines indicate that residential uses, such as the Project, are considered normally acceptable with exterior noise levels of up to 60 dBA CNEL. (9) The noise contour boundaries of MARB/IPA are presented on Exhibit 3-B of this report and show that the Project is considered normally acceptable land use since it is located outside of the 60 dBA CNEL contour boundary.
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EXHIBIT 3-B: AIRPORT NOISE LEVEL CONTOURS
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4 SIGNIFICANCE CRITERIA The following significance criteria are based on guidance provided by Appendix G of the California Environmental Quality Act (CEQA) Guidelines. For the purposes of this report, impacts would be potentially significant if the Project results in or causes: 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 ground-borne vibration or ground-borne 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? 4.1 CEQA GUIDELINES NOT FURTHER ANALYZED In Section 3.6, the noise contour boundaries of MARB/IPA are presented on Exhibit 3-B of this report and show that the Project is considered normally acceptable land use since it is located outside of the 60 dBA CNEL contour. Therefore, impacts are considered less than significant, and no further noise analysis is provided under Guideline C. 4.2 SIGNIFICANCE CRITERIA SUMMARY Noise impacts shall be considered significant if any of the following occur as a direct result of the proposed development. Table 4-1 shows the significance criteria summary matrix.
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TABLE 4-1: SIGNIFICANCE CRITERIA SUMMARY Analysis Condition(s) Significance Criteria Daytime Nighttime On-Site Exterior Noise Compatibility1 See Exhibit 3-A State Interior Noise Level Standard2 45 dBA CNEL City Interior Noise Level Standard3 45 dBA Leq 35 dBA Leq Operational See Table 3-13 Construction Exempt from the exterior noise level standards between the hours of 7:00 p.m. and 7:00 a.m. on weekdays, between the hours of 5:00 p.m. and 8:00 a.m. on Saturdays, or at any time on Sunday or a federal holiday.3 Noise Level Threshold4 80 dBA Leq n/a Vibration Level Threshold5 0.3 PPV (in/sec) n/a 1 City of Riverside General Plan Noise Element, Figure N-10 2 State of California Building Code standards (Section 3.2) 3 City of Riverside Municipal Code Title 7` 4 Federal Transit Authority, 2018. 5 Caltrans Transportation and Construction Vibration Manual, April 2020 Table 19. "Daytime" = 7:00 a.m. - 10:00 p.m.; "Nighttime" = 10:00 p.m. - 7:00 a.m.; "PPV" = Peak Particle Velocity This page intentionally left blank Dauchy Avenue Noise Impact Analysis
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5 EXISTING NOISE LEVEL MEASUREMENTS To assess the existing noise level environment, 24-hour noise level measurements were taken at nine locations in the Project study area. The receiver locations were selected to describe and document the existing noise environment within the Project study area. Exhibit 5-A provides the boundaries of the Project study area and the noise level measurement locations. To fully describe the existing noise conditions, noise level measurements were collected by Urban Crossroads, Inc. on Wednesday, November 18, 2020. Appendix 5.1 includes study area photos. 5.1 MEASUREMENT PROCEDURE AND CRITERIA To describe the existing noise environment, the hourly noise levels were measured during typical weekday conditions over a 24-hour period. By collecting individual hourly noise level measurements, it is possible to describe the daytime and nighttime hourly noise levels and calculate the 24-hour CNEL. The long-term noise readings were recorded using Piccolo Type 2 integrating sound level meter and dataloggers. The Piccolo sound level meters were calibrated using a Larson-Davis calibrator, Model CAL 150. All noise meters were programmed in "slow" mode to record noise levels in "A" weighted form. The sound level meters and microphones were equipped with a windscreen during all measurements. All noise level measurement equipment satisfies the American National Standards Institute (ANSI) standard specifications for sound level meters ANSI S1.4-2014/IEC 61672-1:2013. (12) 5.2 NOISE MEASUREMENT LOCATIONS The noise level meters were positioned as close to the nearest sensitive receiver locations as possible to assess the existing ambient hourly noise levels surrounding the Project site. Both Caltrans and the FTA recognize that it is not reasonable to collect noise level measurements that can fully represent every part of a private yard, patio, deck, or balcony normally used for human activity when estimating impacts for new development projects. This is demonstrated in the Caltrans general site location guidelines which indicate that, sites must be free of noise contamination by sources other than sources of interest. Avoid sites located near sources such as barking dogs, lawnmowers, pool pumps, and air conditioners unless it is the express intent of the analyst to measure these sources. (3) Further, FTA guidance states, that it is not necessary nor recommended that existing noise exposure be determined by measuring at every noise-sensitive location in the project area. Rather, the recommended approach is to characterize the noise environment for clusters of sites based on measurements or estimates at representative locations in the community. (7) Based on recommendations of Caltrans and the FTA, it is not necessary to collect measurements at each individual building or residence, because each receiver measurement represents a group of buildings that share acoustical equivalence. (7) Collecting reference ambient noise level measurements at the nearby sensitive receiver locations allows for a comparison of the before and after Project noise levels and is necessary to assess potential noise impacts due to the Project’s contribution to the ambient noise levels.
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EXHIBIT 5-A: NOISE MEASUREMENT LOCATIONS
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5.3 NOISE MEASUREMENT RESULTS The noise measurements presented below focus on the average or equivalent sound levels (Leq). The equivalent sound level (Leq) represents a steady state sound level containing the same total energy as a time varying signal over a given sample period. Table 5-1 identifies the hourly daytime (7:00 a.m. to 10:00 p.m.) and nighttime (10:00 p.m. to 7:00 a.m.) noise levels at each noise level measurement location. TABLE 5-1: 24-HOUR AMBIENT NOISE LEVEL MEASUREMENTS Location1 Description Energy Average Noise Level (dBA Leq)2 Daytime Nighttime L1 Located north of the Project site on Ferrari Drive near existing single-family residential home at 18351 Ferrari Drive. 49.4 46.6 L2 Located north near the northern Project site boundary. 47.1 36.5 L3 Located north of the Project site on Cactus Street near existing single-family residential home at 18386 Cactus Avenue. 63.2 56.2 L4 Located east near the eastern Project site boundary. 49.6 42.9 L5 Located east of the Project site on Dauchy Avenue near existing single family residential homes on Viento Court. 64.7 58.2 L6 Located southeast near the eastern Project site boundary. 45.9 40.8 L7 Located southeast of the Project site on Dauchy Avenue near existing single-family residential home at 14855 Dauchy Avenue. 61.5 54.0 L8 Located south of the Project site on Louis Pasteur Drive near existing single-family residential home at 14855 Louis Pasteur Drive. 49.0 41.5 L9 Located within the Project site. 47.2 36.6
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1 See Exhibit 5-A for the noise level measurement locations. 2 Energy (logarithmic) average levels. The long-term 24-hour measurement worksheets are included in Appendix 5.2. "Daytime" = 7:00 a.m. to 10:00 p.m.; "Nighttime" = 10:00 p.m. to 7:00 a.m.
Table 5-1 provides the (energy average) noise levels used to describe the daytime and nighttime ambient conditions. These daytime and nighttime energy average noise levels represent the average of all hourly noise levels observed during these time periods expressed as a single number. Appendix 5.2 provides summary worksheets of the noise levels for each hour as well as the minimum, maximum, L1, L2, L5, L8, L25, L50, L90, L95, and L99 percentile noise levels observed during the daytime and nighttime periods.
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6 METHODS AND PROCEDURES The following section outlines the methods and procedures used to model and analyze the on-site traffic noise levels as well as the Project-related construction noise and vibration levels. 6.1 TRAFFIC NOISE PREDICTION MODEL INPUTS The expected roadway noise levels from vehicular traffic were calculated by Urban Crossroads, Inc. using the Federal Highway Administration (FHWA) Traffic Noise Model (TNM) protocol in CadnaA. To predict the future on-site noise environment at the Project site, parameters including the number of lanes and daily volume thresholds were obtained from the City of Riverside General Plan Transportation Element. (13) According to Figure CCM-4 of the Circulation Element, Ferrari Drive and Dauchy Avenue are considered two-lane collector roadways with estimated average daily traffic volume of 12,500 and vehicle speeds of 40 miles per hour as shown on Table 6-1. The traffic volumes shown on Table 6-1 reflect long-range traffic conditions needed to assess the future on-site traffic noise environment and to identify potential mitigation measures (if any) that address the worst-case future conditions. TABLE 6-1: ROADWAY PARAMETERS Roadway Segment Classification1 Future ADT Volume1 Speed (mph) Ferrari Dr. Collector 12,500 40 Dauchy Av. Collector 12,500 40 1 Roadway classification provided in the City of Riverside General Plan Circulation Element (Figure CCM-4). Table 6-2 presents the time-of-day vehicle distribution representing the total daily percentages of traffic for the daytime, evening, and nighttime periods for input into the CadnaA noise prediction model. The analysis assumes that medium trucks represent two percent of the vehicle mix and that heavy trucks represent one percent of the vehicle mix. TABLE 6-2: TIME OF DAY VEHICLE DISTRIBUTION Roadway Classification1 Time of Day Vehicle Distribution2 Daytime Evening Nighttime Total Collector 74.85% 13.68% 11.47% 100.00% 1 County of Riverside Office of Industrial Hygiene, 2017. 2 "Daytime" = 7:00 a.m. to 7:00 p.m.; "Evening" = 7:00 p.m. to 10:00 p.m.; "Nighttime" = 10:00 p.m. to 7:00 a.m.
The Project site plan is used to identify the relationship between the roadway centerline elevation, the pad elevation and the centerline distance to any intervening noise barriers, and the building façade. To assess the on-site traffic noise levels, exterior receivers were placed on selected lots facing Ferrari Drive and Dauchy Avenue as shown on Exhibit 6-A five feet above the pad elevation at the proposed building façade for first floor.
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EXHIBIT 6-A: ON-SITE LOT LOCATIONS
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6.2 CADNAA NOISE PREDICTION MODEL To fully describe the on-site traffic noise levels at the Project site, Urban Crossroads, Inc. developed a noise prediction model using the CadnaA (Computer Aided Noise Abatement) computer program. CadnaA can analyze multiple types of noise sources using the spatially accurate Project site plan, topography, buildings, and barriers in its calculations to predict exterior noise levels. Using the ISO 9613 and the TNM protocols, CadnaA will calculate the distance from each noise source to the noise receiver locations, using the ground absorption, distance, and barrier/building attenuation inputs to provide a summary of noise level at each receiver and the partial noise level contributions by noise source. Consistent with the ISO 9613 protocol, the CadnaA noise prediction model relies on the reference sound power level (Lw) to describe individual noise sources. While sound pressure levels (e.g. Leq) quantify in decibels the intensity of given sound sources at a reference distance, sound power levels (Lw) are connected to the sound source and are independent of distance. Sound pressure levels vary substantially with distance from the source and diminish from intervening obstacles and barriers, air absorption, wind, and other factors. Sound power is the acoustical energy emitted by the sound source and is an absolute value that is not affected by the environment. The noise level calculations provided in this noise study account for the distance attenuation provided due to geometric spreading. A default ground attenuation factor of 0.0 was used in the CadnaA noise analysis to account for hard site conditions. 6.3 CONSTRUCTION NOISE SOURCES Noise generated by the Project construction equipment will include a combination of trucks, power tools, concrete mixers, and portable generators operating simultaneously that when combined can reach high levels. The Project is construction noise sources are expected to include a combination of loaders, cranes, welders, drill rigs, diesel generators, concrete pumps, and mixture of other construction equipment. The Project will not require blasting. 6.4 REFERENCE CONSTRUCTION NOISE LEVELS The FTA Transit Noise and Vibration Impact Assessment Manual recognizes that construction projects are accomplished in several different stages. Each stage has a specific equipment mix, depending on the work to be completed during that stage. As a result of the equipment mix, each stage has its own noise characteristics; some stages have higher continuous noise levels than others, and some have higher impact noise levels than others. The Project construction activities are expected to occur in the following stages: • Site Preparation • Grading • Building Construction • Paving • Architectural Coating Dauchy Avenue Noise Impact Analysis
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This construction noise analysis was prepared using reference noise level measurements taken by Urban Crossroads, Inc. to describe the typical construction activity noise levels for each stage of Project construction. The construction reference noise level measurements represent a list of typical construction activity noise levels. 6.5 TYPICAL CONSTRUCTION REFERENCE NOISE LEVELS To describe the Project typical construction noise levels, measurements were collected for similar activities at several construction sites. Table 6-3 provides a summary of the construction reference noise level measurements. Since the reference noise levels were collected at varying distances, all construction noise level measurements presented on Table 6-3 have been adjusted for consistency to describe a uniform reference distance of 50 feet. Construction noise generated from concrete crushing activities and nighttime concrete pours are addressed separately, below. TABLE 6-3: CONSTRUCTION REFERENCE NOISE LEVELS Construction Stage Reference Construction Activity1 Reference Noise Level @ 50 Feet (dBA Leq) Highest Reference Noise Level (dBA Leq) Site Preparation Scraper, Water Truck, & Dozer Activity 75.3 75.3 Backhoe 64.2 Water Truck Pass-By & Backup Alarm 71.9 Grading Rough Grading Activities 73.5 73.5 Water Truck Pass-By & Backup Alarm 71.9 Construction Vehicle Maintenance Activities 67.5 Building Construction Foundation Trenching 68.2 71.6 Framing 62.3 Concrete Mixer Backup Alarms & Air Brakes 71.6 Paving Concrete Mixer Truck Movements 71.2 71.2 Concrete Paver Activities 65.6 Concrete Mixer Pour & Paving Activities 65.9 Architectural Coating Air Compressors 65.2 65.2 Generator 64.9 Crane 62.3 1 Reference construction noise level measurements taken by Urban Crossroads, Inc.
6.6 TYPICAL CONSTRUCTION REFERENCE VIBRATION LEVELS Construction activity can result in varying degrees of ground vibration, depending on the equipment and methods employed. Operation of construction equipment causes ground vibrations that spread through the ground and diminish in strength with distance. Ground vibration levels associated with various types of construction equipment are summarized on Table 6-4. Based on the representative vibration levels presented for various construction Dauchy Avenue Noise Impact Analysis
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equipment types, it is possible to estimate the potential for human response (annoyance) and building damage using the following vibration assessment methods defined by the FTA. To describe the vibration impacts the FTA provides the following equation: PPVequip = PPVref x (25/D)1.5 TABLE 6-4: VIBRATION SOURCE LEVELS FOR CONSTRUCTION EQUIPMENT Equipment PPV (in/sec) at 25 feet Small bulldozer 0.003 Jackhammer 0.035 Loaded Trucks 0.076 Large bulldozer 0.089 Federal Transit Administration, Transit Noise and Vibration Impact Assessment Manual Dauchy Avenue Noise Impact Analysis
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7 ON-SITE TRAFFIC NOISE Using FHWA’s TNM protocol in CadnaA, and the parameters outlined in Tables 6-1 and 6-2, the expected future exterior noise levels for selected lots were calculated. 7.1 EXTERIOR NOISE/LAND USE COMPATIBILITY The Noise/Land Use Noise Compatibility Criteria (Figure N-10) in the City of Riverside General Plan Noise Element provides guidelines to evaluate the land use compatibility as shown on Exhibit 3-A. A summary of exterior noise/land use compatibility for the single-family residential project use shown on Table 7-1 shows that the unmitigated exterior noise levels will range from 49.1 to 64.1 dBA CNEL. On-Site Receiver locations and walls included in the Project design are shown in Exhibit 7-A. The detailed CadnaA noise prediction model inputs and the exterior noise level calculations are included in Appendix 7.1. TABLE 7-1: EXTERIOR NOISE/LAND USE COMPATIBILITY Lot 24-Hr Exterior Noise Levels (dBA CNEL)2 Land Use Compatibility3 R01 63.2 Conditionally Acceptable R02 60.5 Conditionally Acceptable R03 58.9 Normally Acceptable R04 57.6 Normally Acceptable R05 55.9 Normally Acceptable R06 54.2 Normally Acceptable R07 58.5 Normally Acceptable R08 59.1 Normally Acceptable R09 59.0 Normally Acceptable R10 59.7 Normally Acceptable R11 60.3 Conditionally Acceptable R12 60.9 Conditionally Acceptable R13 60.8 Conditionally Acceptable R14 61.2 Conditionally Acceptable R15 59.4 Normally Acceptable R16 57.7 Normally Acceptable R17 56.4 Normally Acceptable R18 55.5 Normally Acceptable R19 54.8 Normally Acceptable R20 54.2 Normally Acceptable R21 55.2 Normally Acceptable Dauchy Avenue Noise Impact Analysis
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TABLE 7-1: EXTERIOR NOISE/LAND USE COMPATIBILITY
Lot 24-Hr Exterior Noise Levels (dBA CNEL)2 Land Use Compatibility3 R22 51.7 Normally Acceptable R23 55.2 Normally Acceptable R24 55.0 Normally Acceptable R25 55.9 Normally Acceptable R26 56.8 Normally Acceptable R27 58.1 Normally Acceptable R28 59.4 Normally Acceptable R29 59.0 Normally Acceptable R30 57.0 Normally Acceptable R31 55.4 Normally Acceptable R32 54.6 Normally Acceptable R33 54.4 Normally Acceptable R34 54.1 Normally Acceptable R35 51.5 Normally Acceptable R36 51.9 Normally Acceptable R37 51.3 Normally Acceptable R38 51.2 Normally Acceptable R39 50.9 Normally Acceptable R40 50.8 Normally Acceptable R41 49.5 Normally Acceptable R42 49.2 Normally Acceptable R43 49.7 Normally Acceptable R44 50.1 Normally Acceptable R45 50.4 Normally Acceptable R46 50.7 Normally Acceptable R47 50.6 Normally Acceptable R48 51.7 Normally Acceptable R49 53.2 Normally Acceptable R50 55.3 Normally Acceptable R51 56.8 Normally Acceptable R52 59.0 Normally Acceptable R53 61.9 Conditionally Acceptable 1 See Exhibit 7-A for the on-site lot locations. 2 CadnaA noise model inputs and calculations are included in Appendix 7.1. 3 Figure N-10 of the City of Riverside General Plan Noise Element (Single Family Residential).
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EXHIBIT 7-A: ON-SITE RECEIVERS AND BARRIER LOCATIONS
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According to Noise/Land Use Noise Compatibility Criteria for single-family residential land use, the Dauchy Avenue Project will experience unmitigated exterior noise levels that are considered conditionally acceptable at Lots 1, 2, 11 through 14, and 53, represented by receivers 1, 2, 11 through 14, and 53. For conditionally acceptable noise/land use compatibility, Figure N-10 indicates that new construction or development should be undertaken only after a detailed analysis of noise reduction requirements is made and needed noise insulation features included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning will normally suffice. As shown in Table 7-1, the remainder of the lots will experience unmitigated exterior noise levels that are considered normally acceptable. For normally acceptable noise/land use compatibility, Figure N-10 indicates that specific land use is satisfactory, based on the assumption that any building is of normal construction without any special noise insulation requirements. Based on the future unmitigated exterior noise levels at the Project site, additional interior noise analysis is required to satisfy the General Plan Noise Element Figure N-10 noise/land use compatibility requirements for the single-family residential use (Lots 1, 2, 11 through 14, and 53) of the Project site. (9) 7.2 INTERIOR NOISE ANALYSIS The interior noise level is the difference between the predicted exterior noise level at the building facade and the Noise Reduction (NR) of the structure. Typical building construction will provide a NR of approximately 12 dBA with "windows open" and a minimum 25 dBA noise reduction with "windows closed." (14) However, sound leaks, cracks and openings within the window assembly can greatly diminish its effectiveness in reducing noise. Several methods are used to improve interior noise reduction, including: (1) weather-stripped solid core exterior doors; (2) upgraded dual glazed windows; (3) mechanical ventilation/air conditioning; and (4) exterior wall/roof assembles free of cut outs or openings. Table 7-2 shows the future exterior first floor daytime noise levels at the building façades are expected to range from 48.1 to 63.5 dBA Leq requiring an interior noise level reduction ranging from 3.1 to 18.5 dBA Leq. Table 7-3 shows the future exterior first floor nighttime noise levels at the building façades are expected to range from 40.8 to 56.2 dBA Leq requiring an interior noise level reduction ranging from 5.8 to 21.2 dBA Leq. Table 7-3 shows the future exterior first floor daytime noise levels at the building façades are expected to range from 49.2 to 62.8 dBA Leq requiring an interior noise level reduction ranging from 4.2 to 17.8 dBA Leq. Table 7-4 shows the future exterior first floor nighttime noise levels at the building façades are expected to range from 41.9 to 55.5 dBA Leq requiring an interior noise level reduction ranging from 6.9 to 20.5 dBA Leq. Therefore, a windows-closed condition requiring a means of mechanical ventilation (e.g. air conditioning) is required for all lots. The interior noise level analysis shows that the City of Riverside 45 dBA Leq daytime and 35 dBA Leq nighttime interior noise standards can be satisfied using mechanical ventilation and standard windows with a minimum STC rating of 27. The recommended interior noise abatement measures are outlined in the Executive Summary.
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TABLE 7-2: FIRST FLOOR DAYTIME INTERIOR NOISE LEVELS
Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R01 62.2 17.2 25.0 No 37.2 45 No R02 63.5 18.5 25.0 No 38.5 45 No R03 59.5 14.5 25.0 No 34.5 45 No R04 60.8 15.8 25.0 No 35.8 45 No R05 58.3 13.3 25.0 No 33.3 45 No R06 57.6 12.6 25.0 No 32.6 45 No R07 57.1 12.1 25.0 No 32.1 45 No R08 58.1 13.1 25.0 No 33.1 45 No R09 58.0 13.0 25.0 No 33.0 45 No R10 58.7 13.7 25.0 No 33.7 45 No R11 59.3 14.3 25.0 No 34.3 45 No R12 59.9 14.9 25.0 No 34.9 45 No R13 59.7 14.7 25.0 No 34.7 45 No R14 60.1 15.1 25.0 No 35.1 45 No R15 58.4 13.4 25.0 No 33.4 45 No R16 56.6 11.6 25.0 No 31.6 45 No R17 55.3 10.3 25.0 No 30.3 45 No R18 54.4 9.4 25.0 No 29.4 45 No R19 53.8 8.8 25.0 No 28.8 45 No R20 53.1 8.1 25.0 No 28.1 45 No R21 54.2 9.2 25.0 No 29.2 45 No R22 50.6 5.6 25.0 No 25.6 45 No R23 54.2 9.2 25.0 No 29.2 45 No R24 54.0 9.0 25.0 No 29.0 45 No R25 54.9 9.9 25.0 No 29.9 45 No R26 55.7 10.7 25.0 No 30.7 45 No R27 57.1 12.1 25.0 No 32.1 45 No R28 58.4 13.4 25.0 No 33.4 45 No R29 58.0 13.0 25.0 No 33.0 45 No R30 56.0 11.0 25.0 No 31.0 45 No R31 54.4 9.4 25.0 No 29.4 45 No R32 53.6 8.6 25.0 No 28.6 45 No R33 53.4 8.4 25.0 No 28.4 45 No R34 53.0 8.0 25.0 No 28.0 45 No R35 50.5 5.5 25.0 No 25.5 45 No R36 50.8 5.8 25.0 No 25.8 45 No Dauchy Avenue Noise Impact Analysis
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TABLE 7-2: FIRST FLOOR DAYTIME INTERIOR NOISE LEVELS
Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R37 50.3 5.3 25.0 No 25.3 45 No R38 50.2 5.2 25.0 No 25.2 45 No R39 49.9 4.9 25.0 No 24.9 45 No R40 49.7 4.7 25.0 No 24.7 45 No R41 48.5 3.5 25.0 No 23.5 45 No R42 48.2 3.2 25.0 No 23.2 45 No R43 48.7 3.7 25.0 No 23.7 45 No R44 49.1 4.1 25.0 No 24.1 45 No R45 49.4 4.4 25.0 No 24.4 45 No R46 49.7 4.7 25.0 No 24.7 45 No R47 49.5 4.5 25.0 No 24.5 45 No R48 50.7 5.7 25.0 No 25.7 45 No R49 52.2 7.2 25.0 No 27.2 45 No R50 54.3 9.3 25.0 No 29.3 45 No R51 55.7 10.7 25.0 No 30.7 45 No R52 57.9 12.9 25.0 No 32.9 45 No R53 60.9 15.9 25.0 No 35.9 45 No 1 Exterior noise level at the facade with a windows closed condition requiring a means of mechanical ventilation (e.g. air conditioning). 2 Noise reduction required to satisfy the 45 dBA CNEL interior noise standard. 3 Estimated minimum interior noise reduction. 4 Does the required interior noise reduction trigger upgraded windows with a minimum STC rating of greater than 27? 5 Estimated interior noise level with minimum STC rating for all windows. 6 City of Riverside, Municipal Code Section 7.30.015. "NR" = Noise Reduction
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TABLE 7-3: FIRST FLOOR NIGHTTIME INTERIOR NOISE LEVELS Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R01 54.9 19.9 25.0 No 29.9 35 No R02 56.2 21.2 25.0 No 31.2 35 No R03 52.2 17.2 25.0 No 27.2 35 No R04 53.5 18.5 25.0 No 28.5 35 No R05 51.0 16.0 25.0 No 26.0 35 No R06 50.2 15.2 25.0 No 25.2 35 No R07 49.7 14.7 25.0 No 24.7 35 No R08 50.8 15.8 25.0 No 25.8 35 No R09 50.7 15.7 25.0 No 25.7 35 No R10 51.4 16.4 25.0 No 26.4 35 No R11 51.9 16.9 25.0 No 26.9 35 No R12 52.6 17.6 25.0 No 27.6 35 No R13 52.4 17.4 25.0 No 27.4 35 No R14 52.8 17.8 25.0 No 27.8 35 No R15 51.1 16.1 25.0 No 26.1 35 No R16 49.3 14.3 25.0 No 24.3 35 No R17 48.0 13.0 25.0 No 23.0 35 No R18 47.1 12.1 25.0 No 22.1 35 No R19 46.5 11.5 25.0 No 21.5 35 No R20 45.8 10.8 25.0 No 20.8 35 No R21 46.9 11.9 25.0 No 21.9 35 No R22 43.3 8.3 25.0 No 18.3 35 No R23 46.9 11.9 25.0 No 21.9 35 No R24 46.7 11.7 25.0 No 21.7 35 No R25 47.5 12.5 25.0 No 22.5 35 No R26 48.4 13.4 25.0 No 23.4 35 No R27 49.8 14.8 25.0 No 24.8 35 No R28 51.1 16.1 25.0 No 26.1 35 No R29 50.6 15.6 25.0 No 25.6 35 No R30 48.7 13.7 25.0 No 23.7 35 No R31 47.1 12.1 25.0 No 22.1 35 No R32 46.3 11.3 25.0 No 21.3 35 No R33 46.1 11.1 25.0 No 21.1 35 No R34 45.7 10.7 25.0 No 20.7 35 No R35 43.2 8.2 25.0 No 18.2 35 No R36 43.5 8.5 25.0 No 18.5 35 No Dauchy Avenue Noise Impact Analysis
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TABLE 7-3: FIRST FLOOR NIGHTTIME INTERIOR NOISE LEVELS Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R37 43.0 8.0 25.0 No 18.0 35 No R38 42.8 7.8 25.0 No 17.8 35 No R39 42.6 7.6 25.0 No 17.6 35 No R40 42.4 7.4 25.0 No 17.4 35 No R41 41.2 6.2 25.0 No 16.2 35 No R42 40.9 5.9 25.0 No 15.9 35 No R43 41.3 6.3 25.0 No 16.3 35 No R44 41.8 6.8 25.0 No 16.8 35 No R45 42.1 7.1 25.0 No 17.1 35 No R46 42.4 7.4 25.0 No 17.4 35 No R47 42.2 7.2 25.0 No 17.2 35 No R48 43.4 8.4 25.0 No 18.4 35 No R49 44.9 9.9 25.0 No 19.9 35 No R50 47.0 12.0 25.0 No 22.0 35 No R51 48.4 13.4 25.0 No 23.4 35 No R52 50.6 15.6 25.0 No 25.6 35 No R53 53.6 18.6 25.0 No 28.6 35 No 1 Exterior noise level at the facade with a windows closed condition requiring a means of mechanical ventilation (e.g. air conditioning). 2 Noise reduction required to satisfy the 45 dBA CNEL interior noise standard. 3 Estimated minimum interior noise reduction. 4 Does the required interior noise reduction trigger upgraded windows with a minimum STC rating of greater than 27? 5 Estimated interior noise level with minimum STC rating for all windows. 6 City of Riverside, Municipal Code Section 7.30.015. "NR" = Noise Reduction
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TABLE 7-3: SECOND FLOOR DAYTIME INTERIOR NOISE LEVELS
Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R01 62.8 17.8 25.0 No 37.8 45 No R02 59.9 14.9 25.0 No 34.9 45 No R03 58.0 13.0 25.0 No 33.0 45 No R04 57.0 12.0 25.0 No 32.0 45 No R05 56.1 11.1 25.0 No 31.1 45 No R06 55.7 10.7 25.0 No 30.7 45 No R07 57.5 12.5 25.0 No 32.5 45 No R08 58.3 13.3 25.0 No 33.3 45 No R09 59.0 14.0 25.0 No 34.0 45 No R10 59.5 14.5 25.0 No 34.5 45 No R11 59.4 14.4 25.0 No 34.4 45 No R12 59.6 14.6 25.0 No 34.6 45 No R13 59.9 14.9 25.0 No 34.9 45 No R14 60.4 15.4 25.0 No 35.4 45 No R15 57.8 12.8 25.0 No 32.8 45 No R16 56.6 11.6 25.0 No 31.6 45 No R17 55.8 10.8 25.0 No 30.8 45 No R18 55.2 10.2 25.0 No 30.2 45 No R19 54.7 9.7 25.0 No 29.7 45 No R20 54.3 9.3 25.0 No 29.3 45 No R21 54.4 9.4 25.0 No 29.4 45 No R22 53.2 8.2 25.0 No 28.2 45 No R23 54.2 9.2 25.0 No 29.2 45 No R24 54.7 9.7 25.0 No 29.7 45 No R25 55.3 10.3 25.0 No 30.3 45 No R26 55.9 10.9 25.0 No 30.9 45 No R27 56.8 11.8 25.0 No 31.8 45 No R28 57.7 12.7 25.0 No 32.7 45 No R29 58.2 13.2 25.0 No 33.2 45 No R30 57.1 12.1 25.0 No 32.1 45 No R31 55.9 10.9 25.0 No 30.9 45 No R32 55.3 10.3 25.0 No 30.3 45 No R33 54.7 9.7 25.0 No 29.7 45 No R34 54.0 9.0 25.0 No 29.0 45 No R35 53.3 8.3 25.0 No 28.3 45 No R36 52.6 7.6 25.0 No 27.6 45 No Dauchy Avenue Noise Impact Analysis
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TABLE 7-3: SECOND FLOOR DAYTIME INTERIOR NOISE LEVELS
Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R37 52.0 7.0 25.0 No 27.0 45 No R38 51.5 6.5 25.0 No 26.5 45 No R39 51.7 6.7 25.0 No 26.7 45 No R40 N/A N/A N/A N/A N/A N/A N/A R41 N/A N/A N/A N/A N/A N/A N/A R42 N/A N/A N/A N/A N/A N/A N/A R43 49.8 4.8 25.0 No 24.8 45 No R44 50.3 5.3 25.0 No 25.3 45 No R45 50.9 5.9 25.0 No 25.9 45 No R46 51.5 6.5 25.0 No 26.5 45 No R47 51.2 6.2 25.0 No 26.2 45 No R48 51.9 6.9 25.0 No 26.9 45 No R49 53.3 8.3 25.0 No 28.3 45 No R50 54.9 9.9 25.0 No 29.9 45 No R51 55.7 10.7 25.0 No 30.7 45 No R52 57.7 12.7 25.0 No 32.7 45 No R53 61.0 16.0 25.0 No 36.0 45 No 1 Exterior noise level at the facade with a windows closed condition requiring a means of mechanical ventilation (e.g. air conditioning). 2 Noise reduction required to satisfy the 45 dBA CNEL interior noise standard. 3 Estimated minimum interior noise reduction. 4 Does the required interior noise reduction trigger upgraded windows with a minimum STC rating of greater than 27? 5 Estimated interior noise level with minimum STC rating for all windows. "NR" = Noise Reduction; N/A = Not applicable to lots due to zoning restrictions.
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TABLE 7-4: SECOND FLOOR NIGHTTIME INTERIOR NOISE LEVELS Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R01 55.5 20.5 25.0 No 30.5 35 No R02 52.6 17.6 25.0 No 27.6 35 No R03 50.7 15.7 25.0 No 25.7 35 No R04 49.7 14.7 25.0 No 24.7 35 No R05 48.8 13.8 25.0 No 23.8 35 No R06 48.4 13.4 25.0 No 23.4 35 No R07 50.2 15.2 25.0 No 25.2 35 No R08 51.0 16.0 25.0 No 26.0 35 No R09 51.7 16.7 25.0 No 26.7 35 No R10 52.1 17.1 25.0 No 27.1 35 No R11 52.0 17.0 25.0 No 27.0 35 No R12 52.3 17.3 25.0 No 27.3 35 No R13 52.6 17.6 25.0 No 27.6 35 No R14 53.1 18.1 25.0 No 28.1 35 No R15 50.5 15.5 25.0 No 25.5 35 No R16 49.2 14.2 25.0 No 24.2 35 No R17 48.5 13.5 25.0 No 23.5 35 No R18 47.9 12.9 25.0 No 22.9 35 No R19 47.4 12.4 25.0 No 22.4 35 No R20 47.0 12.0 25.0 No 22.0 35 No R21 47.1 12.1 25.0 No 22.1 35 No R22 45.9 10.9 25.0 No 20.9 35 No R23 46.9 11.9 25.0 No 21.9 35 No R24 47.3 12.3 25.0 No 22.3 35 No R25 48.0 13.0 25.0 No 23.0 35 No R26 48.5 13.5 25.0 No 23.5 35 No R27 49.4 14.4 25.0 No 24.4 35 No R28 50.4 15.4 25.0 No 25.4 35 No R29 50.9 15.9 25.0 No 25.9 35 No R30 49.8 14.8 25.0 No 24.8 35 No R31 48.6 13.6 25.0 No 23.6 35 No R32 48.0 13.0 25.0 No 23.0 35 No R33 47.4 12.4 25.0 No 22.4 35 No R34 46.7 11.7 25.0 No 21.7 35 No R35 46.0 11.0 25.0 No 21.0 35 No R36 45.3 10.3 25.0 No 20.3 35 No Dauchy Avenue Noise Impact Analysis
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TABLE 7-4: SECOND FLOOR NIGHTTIME INTERIOR NOISE LEVELS Lot Noise Level at Façade1 Required Interior NR2 Estimated Interior NR3 Upgraded Windows4 Interior Noise Level5 Threshold6 Threshold Exceeded? R37 44.7 9.7 25.0 No 19.7 35 No R38 44.2 9.2 25.0 No 19.2 35 No R39 44.4 9.4 25.0 No 19.4 35 No R40 N/A N/A N/A N/A N/A N/A N/A R41 N/A N/A N/A N/A N/A N/A N/A R42 N/A N/A N/A N/A N/A N/A N/A R43 42.5 7.5 25.0 No 17.5 35 No R44 43.0 8.0 25.0 No 18.0 35 No R45 43.6 8.6 25.0 No 18.6 35 No R46 44.2 9.2 25.0 No 19.2 35 No R47 43.9 8.9 25.0 No 18.9 35 No R48 44.5 9.5 25.0 No 19.5 35 No R49 46.0 11.0 25.0 No 21.0 35 No R50 47.6 12.6 25.0 No 22.6 35 No R51 48.3 13.3 25.0 No 23.3 35 No R52 50.4 15.4 25.0 No 25.4 35 No R53 53.6 18.6 25.0 No 28.6 35 No 1 Exterior noise level at the facade with a windows closed condition requiring a means of mechanical ventilation (e.g. air conditioning). 2 Noise reduction required to satisfy the 45 dBA CNEL interior noise standard. 3 Estimated minimum interior noise reduction. 4 Does the required interior noise reduction trigger upgraded windows with a minimum STC rating of greater than 27? 5 Estimated interior noise level with minimum STC rating for all windows. "NR" = Noise Reduction; N/A = Not applicable to lots due to zoning restrictions.
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8 OFF-SITE TRAFFIC NOISE Traffic generated by the operation of the proposed Project is not expected to meaningfully influence the traffic noise levels in surrounding off-site areas. The expected Project traffic represents an incremental increase to the existing roadway volumes, which is not expected to generate a barely perceptible noise level increase of 3 dBA CNEL at nearby sensitive land uses adjacent to study area roadways, since a doubling of the existing traffic volumes would be required to generate a 3 dBA CNEL increase. (2) Due to the low traffic volumes generated by the Project, the off-site traffic noise levels generated by the Project are considered less than significant and no further analysis is required.
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9 OFF-SITE SENSITIVE RECEIVER LOCATIONS To assess the potential for off-site operational and short-term construction noise impacts, the following receiver locations, as shown on Exhibit 9-A, were identified as representative locations for analysis. Sensitive receiver locations are generally defined as “[a]n area where noise interferes with normal activities associated with its use. Normally, noise sensitive areas include residential, educational, health, and religious structures and sites, and parks, recreational areas, areas with wilderness characteristics, wildlife refuges, and cultural and historical sites (15).” Moderately noise-sensitive land uses typically include multi-family dwellings, hotels, motels, dormitories, out-patient clinics, cemeteries, golf courses, country clubs, athletic/tennis clubs, and equestrian clubs. Land uses that are considered relatively insensitive to noise include business, commercial, and professional developments. Land uses that are typically not affected by noise include: industrial, manufacturing, utilities, agriculture, undeveloped land, parking lots, warehousing, liquid and solid waste facilities, salvage yards, and transit terminals. To describe the potential off-site Project noise levels, nine receiver locations in the vicinity of the Project site were identified. All distances are measured from the Project site boundary to the outdoor living areas (e.g., private backyards) or at the building façade, whichever is closer to the Project site. Other sensitive land uses in the Project study area that are located at greater distances than those identified in this noise study will experience lower noise levels than those presented in this report due to the additional attenuation from distance and the shielding of intervening structures. Distance is measured in a straight line from the project boundary to each receiver location. R1: Location R1 represents the property line of the existing residence at 18351 Ferrari Drive, approximately 35 feet northwest of the Project site. A 24-hour noise measurement was taken near this location, L1, to describe the existing ambient noise environment. Location R1 represents a non-residential land use. R2: Location R2 represents the northern Project site property line. A 24-hour noise measurement was taken near this location, L2, to describe the existing ambient noise environment. R3: Location R3 represents the property line of the existing noise sensitive residence 18386 Cactus Avenue, approximately 753 feet north of the Project site. A 24-hour noise measurement was taken near this location, L3, to describe the existing ambient noise environment. R4: Location R4 represents the eastern Project site property line. A 24-hour noise measurement was taken near this location, L4, to describe the existing ambient noise environment. R5: Location R5 represents the property line of the existing noise sensitive residence on Viento Court, approximately 261 feet east of the Project site. A 24-hour noise measurement was taken near this location, L5, to describe the existing ambient noise environment. R6: Location R6 represents the southeastern Project site property line. A 24-hour noise measurement was taken near this location, L6, to describe the existing ambient noise environment.
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R7: Location R7 represents the property line of the existing noise sensitive residence at 14855 Dauchy Avenue, approximately 451 feet southeast of the Project site. A 24-hour noise measurement was taken near this location, L7, to describe the existing ambient noise environment. R8: Location R8 represents the property line of the existing noise sensitive residence at 14855 Louis Pasteur Drive, approximately 84 feet southwest of the Project site. A 24-hour noise measurement was taken near this location, L8, to describe the existing ambient noise environment. R9: Location R9 represents the existing noise within the Project site. A 24-hour noise measurement was taken near this location, L9, to describe the existing ambient noise environment.
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EXHIBIT 9-A: RECEIVER LOCATIONS
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10 OPERATIONAL NOISE ANALYSIS This section analyzes the potential stationary-source operational noise impacts at the nearest receiver locations, identified in Section 8, and on-site locations shown on Exhibit 7-A, resulting from the operation of the proposed Dauchy Avenue Project. Exhibit 10-A identifies the representative noise source locations used to assess the operational noise levels. 10.1 OPERATIONAL NOISE SOURCES This operational noise analysis is intended to describe noise level impacts associated with the expected typical of daytime and nighttime activities at the Project site. To present the potential worst-case noise conditions, this analysis assumes the Project would be operational 24 hours per day, seven days per week. Consistent with similar residential land uses, the primary noise source would be ground mounted air conditioner condensers. 10.2 REFERENCE NOISE LEVELS To assess the noise levels created by the ground-mounted air conditioning units, reference noise levels from a Lennox model XC13N used as representative of the air conditioning units that could be used on the Project and have a range of capacity from 1.5 tons to 5 tons. Based on the proposed square footage of each residence, it is estimated each residence would require between 3 to 5 tons of air conditioning. According to the product data sheet a Lennox model XC13N with a capacity ranging from 3 to 5 tons produces a maximum sound power level of 76 dBA, see Appendix 10.1. While operating at full power air conditioners operate in multiple short cycles up to 30 minutes during the nighttime as compared to the daytime where the units typically operate can operate continuously up to 45 minutes in multiple cycles, depending on the ambient temperature. For purposes of this analysis, it was assumed the air conditioners would operate 45 minutes out of an hour during the daytime (7:00 a.m. to 10:00 p.m.) and 30 minutes out of an hour at nighttime (10:00 p.m. to 7:00 a.m.). The acoustic center of each unit will be located three feet above ground elevation.