4.4 NOISE AND VIBRATION - gsws.com to differentiate the sensitivity to ground-borne vibration: Category 1 includes buildings where vibration would interfere with interior operations

Chapter 4 Affected Environment; Environmental Consequences; and Avoidance, Minimization, and Mitigation Measures 4.4 Noise and Vibration

4.4 NOISE AND VIBRATION This section evaluates potential environmental effects related to noise and vibration as a result of the Proposed Action. This section is based on the noise and vibration technical report prepared for the Proposed Action (Appendix C). 4.4.1 Regulatory Setting Noise Control Act of 1972 (42 U.S.C. 4910) The Noise Control Act of 1972 was the first comprehensive statement of national noise policy. The goal of the Noise Control Act was to promote an environment for all Americans free from noise that jeopardizes their health or welfare. Noise Emission Standards for Transportation Equipment and Rail Carriers (40 CFR 201) The USEPA railroad emission standards establish limits for noise emissions from trains. The provisions of this regulation apply to all rail cars and all locomotives, except steam locomotives, operated or controlled by rail carriers. The regulations apply to the total sound level emitted by rail cars and locomotives. These provisions do not apply to the sound emitted by a warning device, such as a horn, whistle, or bell, when operated for the purpose of safety or to electric railways unless operated as a part of a general railroad system of transportation. Federal Transit Administration Guidelines The FTA has established guidelines for the evaluation of transit noise and vibration for trains that operate at speeds generally less than 90 mph; passenger and freight trains operating within the project limits fall into this category. The guidelines are set forth in FTA’s Transit Noise and Vibration Impact Assessment (FTA 2006) and establish impact criteria for rail noise and vibration, define sensitive receivers, and provide methodology for assessing impacts. Noise Sensitive Land Uses The FTA manual defines three categories of land uses to describe the sensitivity to noise: Category 1 includes uses where quiet is an essential element in their intended purpose,

such as outdoor concert halls or pavilions, recording studios, and some National Historic Landmarks.

Category 2 includes residences and buildings where people sleep (such as hotels,

dormitories, and hospitals). Category 3 includes institutional land uses with primarily daytime and evening use. This

category includes schools, libraries, theaters, and churches. In general, commercial and industrial land uses are not considered noise-sensitive.

San Dieguito River Bridge Replacement, Double Track, and Del Mar Fairgrounds Special Events Platform Environmental Assessment 4.4-1 October 2014


Vibration Sensitive Land Uses Land uses in which ground-borne vibration could potentially interfere with operations or equipment, such as research, manufacturing, hospitals, and university research operations, are considered vibration-sensitive. The degree of sensitivity depends on the specific equipment that would be affected by the ground-borne vibration. As with noise, three categories are typically used to differentiate the sensitivity to ground-borne vibration: Category 1 includes buildings where vibration would interfere with interior operations.

Typical land uses covered by Category 1 are manufacturing, hospitals with vibration-sensitive equipment, and research operations. The degree of sensitivity to vibration depends on the specific equipment that will be affected by the vibration.

Category 2 includes residences and buildings where people sleep (hotels, hospitals, and

dormitories). Category 3 includes institutional land uses with primarily daytime use that do not have

vibration-sensitive equipment (schools, churches, office buildings). In addition to the types of facilities listed above under Categories 1 through 3, there are some building types that can be very sensitive to vibration and noise, but do not fit into any of the described categories (e.g., fragile historic structures, concert halls, television and recording studios, and theaters). Such facilities usually warrant special consideration during assessment of noise and vibration effects. Federal Railroad Administration Guidelines The FRA provides guidance and procedures for the assessment of potential noise and vibration impacts resulting from proposed high speed ground transportation projects, including high speed trains using traditional steel wheel on steel rail technologies. The FRA guidelines are intended for projects with train speeds of 90 to 250 mph. Therefore, the FRA guidelines are not directly applicable to the Proposed Action since train speeds associated with the Proposed Action will be less than 90 mph. 4.4.2 Affected Environment The analysis and conclusions presented in this section are based on the noise and vibration technical report prepared for the Proposed Action (Appendix C). The noise and vibration technical report evaluated noise and vibration effects for the Proposed Action alternatives, as well as the No Action Alternative.



Noise and Vibration Study Area The study area for noise and vibration encompasses the railroad corridor between the northern and southern project limits and extends 200 feet east and west of the railroad ROW. For the purposes of the noise and vibration analysis, the project limits were geographically divided into three segments with a total of six sub-segments; this was done to take into account the varying characteristics related to noise and vibration along the project limits, such as topography and land use designations. Figure 4.4-1, Noise and Vibration Analysis Segments, shows the sub-segment divisions, and Table 4.4-1, Land Uses Along Noise and Vibration Analysis Sub-Segments, describes the land uses present along each sub-segment.

Table 4.4-1 LAND USES ALONG NOISE AND VIBRATION ANALYSIS SUB-SEGMENTS

Segment Number

Sub-Segment Limits

Land Uses

Segment 1 North

Northern project limits to

approximately 800 feet north of Via

de la Valle

East of the railroad tracks, this area is currently fully developed with either residential or office and commercial uses. The residential development is adjacent to the existing tracks with some structures (commercial and residential) within 100 feet of the existing tracks. The existing alignment is below grade throughout this area, and partial shielding from a direct line of sight exists between the land use and the ROW. West of the railroad tracks, this area is currently fully developed with either residential or office and commercial uses. These land uses are at a greater distance from the existing alignment than those east of the tracks; Highway 101 and the Coastal Rail Trail are located between the structures and the below-grade alignment.

Segment 1 South

Approximately 800 feet north of Via de la Valle to Via de

la Valle

Residential and commercial uses occur on both east and west sides of the existing tracks. The existing alignment is below grade throughout this area, and partial shielding from a direct line of sight exists between the land use and the ROW. The nearest residence to the west is located within approximately 200 feet of the existing tracks, and the nearest residence to the east is located within approximately 115 feet of the existing tracks.



Table 4.4-1 (cont.) LAND USES ALONG NOISE AND VIBRATION ANALYSIS SUB-SEGMENTS

Segment Number

Sub-Segment Limits

Land Uses

Segment 2

Via de la Valle to the southern bank of

the San Dieguito River

The northernmost portion of this segment is currently developed with residential uses to the east. The nearest residence is located approximately 135 feet east of the existing track in this area. The Del Mar Fairgrounds are located immediately south of this residence. An undeveloped area, predominantly marshland, is located to the west of the railroad tracks.

Segment 3 North

Southern bank of the San Dieguito River1

to 22nd Street

This area is primarily developed with commercial uses to the east of the railroad track. The nearest commercial use is located within approximately 80 feet of the existing track alignment. Additionally, there are residential uses located to the west of the track in this area, with the nearest residence located within 100 feet of the existing railroad track.

Segment 3 Central

22nd Street to approximately

100 feet north of Camino Del Mar

In this area, commercial development transitions to residential uses southward on the eastern side of the existing track, starting approximately 775 feet north of Camino Del Mar. The nearest commercial use is located in the southern portion of this area, approximately 80 feet to the east of the existing track. West of the existing track, this area is developed with residential land uses, with the closest residence approximately 100 feet from the existing rail track.

Segment 3 South

Approximately 100 feet north of

Camino Del Mar to southern project

limits.

Development transitions to predominantly residential uses in this area. The nearest residence to the west is located approximately 50 feet from the existing tracks; the nearest residence to the east is located approximately 100 feet from the existing rail alignment.

1 The division between Segments 2 and 3 North is the southern bank of the San Dieguito River. Due to the course of the river, land immediately south of the river and west of the tracks is considered Segment 3 North, even though some areas are directly west of Segment 2. Source: HELIX 2014b (Appendix C). Fundamentals of Noise and Vibration The following brief description of noise and vibration fundamentals is based on information in the FTA’s Transit Noise and Vibration Impact Assessment (FTA 2006), as applicable, with more detailed descriptions contained in Appendix C.


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Noise Sound can be described as the mechanical energy of a vibrating object transmitted by pressure waves through a liquid or gaseous medium (e.g., air) to a hearing organ, such as a human ear. Noise is defined as loud, unexpected, or annoying sound. Continuous sound can be described by frequency (pitch) and amplitude (loudness), with a low-frequency sound perceived as low in pitch. Frequency is expressed in terms of cycles per second, or Hertz (Hz). The audible frequency range for humans is generally between 20 Hz and 20,000 Hz (or 20 kilohertz [kHz]). A logarithmic scale is used to describe sound pressure level (SPL) in terms of decibels (dB). To approximate the response of the human ear, sound levels of individual frequency bands are weighted, depending on the human sensitivity to those frequencies. An “A-weighted” sound level (expressed in units of dBA) can then be calculated from this information. Noise levels for transportation noise reports are typically reported in terms of A-weighted decibels or dBA. Table 4.4-2, Typical A-Weighted Noise Levels, describes typical A-weighted noise levels for various noise sources.

Table 4.4-2

TYPICAL A-WEIGHTED NOISE LEVELS

Common Outdoor Activities Noise Level

(dBA) Common Indoor Activities

— 110 — Rock band Jet fly-over at 1000 feet — 100 — Gas lawn mower at 3 feet — 90 — Diesel truck at 50 feet at 50 mph Food blender at 3 feet — 80 — Garbage disposal at 3 feet Noisy urban area, daytime Gas lawn mower, 100 feet — 70 — Vacuum cleaner at 10 feet Commercial area Normal speech at 3 feet Heavy traffic at 300 feet — 60 — Large business office Quiet urban daytime — 50 — Dishwasher next room Quiet urban nighttime — 40 — Theater, large conference room

(background) Quiet suburban nighttime — 30 — Library Quiet rural nighttime Bedroom at night, concert — 20 — Broadcast/recording studio — 10 — Lowest threshold of human hearing — 0 — Lowest threshold of human hearing Source: Caltrans 2009.



Various noise descriptors have been developed to describe time-varying noise levels, with the following noise descriptors most commonly used in transportation noise analysis.

• Equivalent Sound Level (LEQ). LEQ represents an average of the sound energy occurring over a specified period.

• Day-Night Level (LDN). LDN is the energy average of A-weighted sound levels occurring

over a 24-hour period, with a 10-dB penalty applied to A-weighted sound levels occurring during nighttime hours between 10 p.m. and 7 a.m.

In general, a doubling of sound energy results in a 3-dB increase in sound. In typical noisy environments, changes in noise of 1 to 2 dB are generally not perceptible, although it is widely accepted that people are able to begin to detect sound level increases of 3 dB in typical noisy environments. In addition, a 5-dB increase is generally perceived as distinctly noticeable, and a 10-dB increase is generally perceived as a doubling of loudness. Accordingly, a doubling of sound energy that would result in a 3-dB increase in sound would generally be perceived as barely detectable by the human ear. Vibration Ground vibration is an oscillatory motion of the soil particles with respect to the equilibrium position that can be described in terms of displacement, velocity, or acceleration. Additionally, the response of humans, buildings, and equipment to vibration is more accurately described by using velocity or acceleration. The earth can sustain two types of waves: “compression” or “primary” waves (P-waves), and “secondary” or “shear” waves (S-waves). These waves are called “body waves.” The particle motion associated with a P-wave is a push-pull motion parallel to the direction of the wave front, whereas particle motion associated with an S-wave is a transverse displacement normal to the direction of the wave front. A third type of wave, called a Rayleigh wave (R-wave), is a seismic surface wave causing the ground to shake in an elliptical motion, with no transverse, or perpendicular, motion. Rayleigh waves include both longitudinal and transverse motions that decrease exponentially in amplitude as distance from the surface increases. Trains and other surface disturbance primarily create energy in R-waves. Vibration velocity levels are expressed as decibels with the notation VdB. The background vibration velocity level in residential areas is usually 50 VdB or lower; this is well below the level perceptible by humans, which is approximately 65 VdB. Common vibration sources and the human and structural response to ground-borne vibration are identified in Figure 4.4-2, Typical Ground-borne Vibration Levels. Vibration is measured by acceleration relative to the earth’s gravity. Acceleration is measured by comparing acceleration to that of the Earth’s gravity, and this unit is “g.” These units of acceleration or velocity are relative to time in seconds and are noted as in/sec2 for acceleration and in/sec for velocity.


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7.2 HUMAN PERCEPTION OF GROUND-BORNE VIBRATION AND NOISE

This section gives some general background on human response to different levels of building vibration,laying the groundwork for the criteria for ground-borne vibration and noise that are presented inChapter 8.

7.2.1 Typical Levels of Ground-Borne Vibration and Noise In contrast to airborne noise, ground-borne vibration is not a phenomenon that most people experience every day. The background vibration velocity level in residential areas is usually 50 VdB or lower, wellbelow the threshold of perception for humans which is around 65 VdB. Most perceptible indoor vibrationis caused by sources within buildings such as operation of mechanical equipment, movement of people or slamming of doors. Typical outdoor sources of perceptible ground-borne vibration are construction equipment, steel-wheeled trains, and traffic on rough roads. If the roadway is smooth, the vibration from traffic is rarely perceptible.

Figure 7-3 illustrates common vibration sources and the human and structural response to ground-bornevibration. The range of interest is from approximately 50 VdB to 100 VdB. Background vibration is usually well below the threshold of human perception and is of concern only when the vibration affects very sensitive manufacturing or research equipment. Electron microscopes and high-resolution lithography equipment are typical of equipment that is highly sensitive to vibration.

Figure 7-3. Typical Levels of Ground-Borne Vibration


Vibration effects can be described by its peak and root mean square (RMS) amplitudes. Building damage is often discussed in terms of peak velocity, or peak particle velocity (PPV). The PPV is defined as the maximum instantaneous positive or negative peak of the vibration signal. The RMS amplitude is useful for assessing human annoyance, while peak vibration is most often used for assessing the potential for damage to buildings and structures (although it has also been used for assessing annoyance). Methodologies and Thresholds Impact Thresholds The impacts from changes in noise and vibration levels attributable to the Proposed Action are based on the guidance provided in FTA’s Transit Noise and Vibration Impact Assessment (FTA 2006). Construction Noise. The FTA guidelines discuss various approaches for analyzing construction noise impacts, varying from brief qualitative assessments to detailed quantitative analyses. The approach for assessing construction noise effects should take into account the existing noise environment, the types of construction activities, the duration of the construction, and the adjacent land use. Qualitative assessments may be appropriate for projects involving a limited amount of construction time (less than a month) or with limited disruption to noise-sensitive land uses. Due to the extent of the construction period for the Proposed Action (approximately three years, including some nighttime activity), the use of construction equipment that would generate substantial amounts of noise (such as vibratory pile driving), and the proximity to residences, a detailed quantitative approach is used in the analysis for the Proposed Action. No standardized criteria have been developed by FTA for assessing construction noise impacts. FTA recommends the following guidelines for detailed assessment criteria of construction noise, as specified in Table 4.4-3, Assessment Criteria for Construction Noise. If these recommended criteria are exceeded, there may be an adverse community reaction.

Table 4.4-3 ASSESSMENT CRITERIA FOR CONSTRUCTION NOISE

Land Use 8-Hour LEQ (dBA) LDN (dBA) Day Night 30-Day Average

Residential 80 70 75 Commercial 85 85 80* Industrial 90 90 85* *24-hour LEQ, not LDN Source: FTA 2006.



Vibration. Construction activity can result in varying degrees of ground vibration, depending on the equipment and methods employed. Similar to construction noise, assessing construction vibration impacts can vary in approach ranging from a very brief assessment to a more detailed approach. Buildings in the vicinity of the construction site may result in impacts from vibration varying from barely perceptible rumbling to structural damage at the highest levels. Older or fragile historic buildings may be more susceptible to damage from vibration. Construction activities that typically generate the most severe vibrations are blasting and impact pile-driving. Human responses to excessive vibration can range from annoyance to interference with vibration-sensitive activities (such as laboratory work). Different thresholds apply to building damage assessment and human annoyance assessment. Due to the extent and type of construction activities associated with the Proposed Action (including vibratory pile driving), a quantitative assessment of construction vibration impacts has been conducted. No vibration-sensitive fragile or historic structures were observed within the study area. Therefore, this analysis uses the human annoyance threshold to assess potential impacts. In evaluating potential annoyance or interference with vibration-sensitive activities due to construction vibration, the same criteria used for operational impacts (see discussion below regarding operational ground-borne vibration and noise) can be used for construction impacts. Normal construction activities are considered infrequent events (refer to Table 4.4-4, Ground-borne Vibration (GBV) and Ground-borne Noise (GBN) Impact Criteria); however, pile driving (specifically, vibratory pile driving for the Proposed Action) is considered a frequent event due to the potential duration of the activity.

Table 4.4-4 GROUND-BORNE VIBRATION (GBV) AND GROUND-BORNE NOISE (GBN)

IMPACT CRITERIA

Land Use Category

GBV Impact Levels (VdB re 1 micro-in/sec)

GBN Impact Levels (dB re 20 mPa)

Frequent Events1

Occasional Events2

Infrequent Events3

Frequent Events1

Occasional Events2

Infrequent Events3

Category 1 65 VdB4 65 VdB4 65 VdB4 N/A5 N/A5 N/A5

Category 2 72 VdB 75 VdB 80 VdB 35 dBA 38 dBA 43 dBA

Category 3 75 VdB 78 VdB 83 VdB 40 dBA 43 dBA 48 dBA 1 Frequent Events is defined as more than 70 vibration events of the same source per day. Most rapid transit projects

fall into this category. 2 Occasional Events is defined as between 30 and 70 vibration events of the same source per day. Most commuter

trunk lines have this many operations. 3 Infrequent Events is defined as fewer than 30 vibration events of the same kind per day. This category includes

most commuter rail branch lines. 4 This criterion limit is based on levels that are acceptable for most moderately sensitive equipment such as optical

microscopes. Vibration-sensitive manufacturing or research will require detailed evaluation to define the acceptable vibration levels. Ensuring lower vibration levels in a building often requires special design of the heating, ventilation, and air conditioning (HVAC) systems and stiffened floors.

5 Vibration-sensitive equipment is generally not sensitive to ground-borne noise. Source: FTA 2006.



Operation Noise. The FTA guidelines describe various methods for assessing noise impacts from transit projects. The approaches include a general screening procedure, a general assessment, and a detailed analysis. If no noise-sensitive receivers are located within the screening distance of a particular type of transit project, no impact is likely to occur and no further analysis is warranted. A general assessment is recommended when an analysis needs to evaluate several alternatives, or when plan specifications are not available. A detailed analysis is typically conducted once project designs are completed so that the effectiveness of mitigation measures can be evaluated on a site-specific basis. For the purposes of this analysis, a general assessment approach has been used to evaluate the differences between the Proposed Action Alternatives, because sensitive receptors are located within close proximity (50 feet) to the rail alignment (the screening distance for a commuter rail mainline is 750 feet). Because the design of the Proposed Action is not completed and still in the preliminary phase, a detailed analysis is not appropriate. The FTA uses different criteria to evaluate noise impacts from rail operations. The basic concept behind the criteria is that as the existing noise levels increase, the allowable noise level increase from a project decreases. The noise criteria used in assessing impacts from transit projects is provided in FTA’s Transit Noise and Vibration Impact Assessment (FTA 2006). These criteria apply to rail projects (e.g., rail rapid transit, light rail transit, commuter rail, and automated guideway transit), as well as fixed facilities such as storage and maintenance yards, passenger stations and terminals, parking facilities, and substations. Pursuant to FTA methodology, estimated noise generated by a new transit project (including heavy rail) is added to the existing ambient noise levels to come up with a new “cumulative” noise level that takes into account all noise sources. However, where proposed projects involve changes to an existing transit system, as opposed to a new transit project in an area previously without transit, the existing noise sources change as a result of the project and do not represent a new noise source, and thus, it is not possible to define project noise separately from existing noise (because the transit noise already contributes to the existing noise). Examples where this condition would apply are projects that include operations of a new type of vehicle, modifications of track alignments within existing transit corridors (which is the case for the Proposed Action), or changes in facilities that dominate existing noise levels. For these types of projects, and thus for the Proposed Action (which proposes to modify existing track alignments), FTA guidance states that the impact assessment must instead apply criteria based on the total increase in noise exposure. Figure 4.4-3, FTA Operational Noise Impact Criteria, shows the noise impact criteria for Category 1 and 2 land uses in terms of the allowable increase in the noise exposure. The horizontal axis represents the existing (baseline) noise exposure and the vertical axis represents the relative increase in noise levels above the baseline that would occur when the Proposed Action is implemented. As shown in Figure 4.4.3, the criterion for a moderate impact allows a noise exposure increase of 10 dBA if the existing noise exposure is 42 dBA or less; additionally, a severe impact would not occur with an exposure increase of less than 15 dBA. When the existing noise exposure is 70 dBA, however, the increase of 1 dBA



would be on the threshold between “No Impact” and “Moderate Impact,” and the increase of 3 dBA would be on the threshold between “Moderate Impact” and “Severe Impact.” For residential land uses, the noise criteria are to be applied outside the building locations at noise-sensitive areas with frequent human use, including outdoor patios, decks, pools, and play areas. If none of these areas is present, the criteria should be applied near building doors and windows. For parks and other outdoor use areas, criteria are to be applied at the property line. Certain building features (window type, building frame type) can provide greater outdoor-to-indoor noise reduction than is provided by typical buildings; for example, an approximately 25 dBA reduction can occur with certain building features and with closed windows. Thus, noise impacts for land uses that involve predominantly indoor activity may be less substantial even if the noise level at the exterior is substantial, due to building features yielding a greater-than-typical outdoor-to-indoor noise reduction. Noise level increases are categorized as no impact, moderate impact, or severe impact. The extent of the impact depends on the magnitude of the noise increase in relation to the baseline noise level. If the increase in noise level due to a project falls within the No Impact range, then a project would not result in an adverse impact. In the Moderate Impact range, the change in the noise level would be noticeable to most people, but may not be sufficient to cause strong, adverse reactions from the community. In this transitional area, other project-specific factors must be considered to determine the magnitude of the impact and the need for mitigation. These factors include the existing noise level, the predicted increase over existing noise levels, the types and numbers of noise-sensitive land uses affected, the noise sensitivity of the affected properties, the effectiveness of possible mitigation measures, community views, and the cost of mitigating the noise. Project-generated noise in the Severe Impact range can be expected to cause a substantial percentage of people to be highly annoyed by the new noise and represents the most compelling need for mitigation. Noise mitigation would normally be specified for severe impact areas unless there are extenuating circumstances which prevent it. Noise–Platform Passenger Noise. The FTA screening distance for a train passenger platform is 200 feet for an adverse noise impact. The FTA guidance indicates that a detailed evaluation of noise impacts from a proposed platform is not required for residences further than 200 feet from the proposed platform. Additional analysis must be conducted for residences within this screening distance to assess potential noise impacts resulting from noise generated by patrons using proposed rail platforms. The FTA guidance states that in order for the platform passenger noise level to be less than adverse, it must be below the threshold of 50 dBA at the noise sensitive receiver, which is the lowest threshold outlined for noise sensitive uses in the guidelines. Ground-borne Vibration and Noise. Similar to noise impacts, FTA includes a screening procedure designed to identify projects that have little possibility of creating an adverse impact. Transit projects that do not involve vehicles do not have potential for vibration impacts unless the track system will be modified. The Proposed Action involves track re-alignment, and therefore the screening distance for a commuter railroad was used for the initial assessment. The screening distance for Category 2 vibration-sensitive uses (residences) is 200 feet, and because residences are located as close as 50 feet to the existing rail tracks, a general assessment was


FTA Operational Noise Impact CriteriaSAN DIEGUITO RIVER BRIDGE, DOUBLE TRACK,

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3-6 Transit Noise and Vibration Impact Assessment

of cumulative noise increase described in Appendix B. To illustrate this point, Figure 3-2 shows the noise impact criteria for Category 1 and 2 land use in terms of the allowable increase in the cumulative noise exposure. The horizontal axis is the existing noise exposure and the vertical axis is the increase in cumulativenoise level due to the transit project. The measure of noise exposure is Ldn for residential areas and Leq for land uses that do not have nighttime noise sensitivity. Since Ldn and Leq are measures of total acoustic energy,any new noise source in a community will cause an increase, even if the new source level is less than the existing level. Referring to Figure 3-2, it can be seen that the criterion for Moderate Impact allows a noise exposure increase of 10 dBA if the existing noise exposure is 42 dBA or less but only a 1 dBA increase whenthe existing noise exposure is 70 dBA

Figure 3-2. Increase in Cumulative Noise Levels Allowed by Criteria (Land Use Cat. 1 &2)

As the existing level of ambient noise increases, the allowable level of transit noise increases, but the total amount that community noise exposure is allowed to increase is reduced. This accounts for the unexpected result that a project noise exposure which is less than the existing noise exposure can still cause impact. Thisis clearer from the examples given in Table 3-3 which indicate the level of transit noise allowed for different existing levels of exposure.


used for ground-borne vibration impacts. Detailed vibration analyses are typically conducted at the final stage of design on a site-specific basis. The criteria for acceptable ground-borne vibration are expressed in terms of RMS velocity levels in decibels and the criteria for acceptable ground-borne noise are expressed in terms of A-weighted sound levels. The impact criteria for general assessment are based on the vibration-sensitive land uses categories (refer to Table 4.4-4). In areas that already experience existing vibration (such as the Proposed Action area) the following approach may be used: Infrequently used rail corridor: Use the vibration criteria from Table 4.4-4 when the

existing rail traffic consists of fewer than five trains per day. Moderately used rail corridor: If the existing traffic consists of 5 to 12 trains per day

with vibration that substantially exceeds the impact criteria, there is no impact as long as the project vibration levels estimated are at least 5 VdB less than the existing vibration.

Heavily used rail corridor: If the existing traffic exceeds 12 trains per day and if the

project will not significantly increase the number of vibration events (less than doubling the number of trains is usually considered not significant), there will not be additional impacts unless the project vibration will be higher than the existing vibration.

Moving existing tracks: Another scenario where existing vibration can be significant is

when a new transit project will use an existing railroad ROW and result in shifting the location of existing railroad tracks. The track relocation and reconstruction can result in lower vibration levels, in which case this aspect of the project represents a benefit, not an adverse impact. If the track relocation will cause higher vibration levels at sensitive receptors, then the projected vibration levels must be compared to the appropriate impact criterion to determine if there will be new impacts. If the impact is judged to have existed prior to moving the tracks, a new impact will be assessed only if the relocation results in more than a 3-VdB increase in vibration level.

The existing frequency of rail operations within the project limits is 50 train trips per weekday. This number is expected to increase to 101 trips in 2030. Therefore, the impact criteria used for this analysis is for frequent events (greater than 70 vibration events per day). However, in areas where the vibration levels currently exceed the threshold, potential impacts from the track relocation are assessed using the criterion of an increase of 3 VdB for vibration over existing conditions. Existing Noise Environment The existing noise environment is comprised of multiple noise sources, including roadways (Highway 101, Camino Del Mar, Jimmy Durante Boulevard, Via de la Valle, and I-5 [a more distant source]), Fairgrounds and racetrack operations, and the existing railroad operations.



Sensitive Receptors Noise Sensitive Land Uses Noise sensitive land uses or receptors are land uses or individuals that may be subject to stress and/or interference from excessive noise. As previously discussed, FTA uses three categories to describe the sensitivity of land uses to noise; these are Category 1 (buildings where quiet is essential, such as concert halls, recording studies and some national historic landmarks), Category 2 (residences and buildings where people normally sleep), and Category 3 (institutional land uses with primarily daytime use) land uses as defined in Section 4.4.1. As mentioned previously, commercial and industrial land uses are generally not considered noise sensitive. Noise-sensitive land uses along the project limits consist of residential (Category 2) uses (refer to Table 4.4-1). Vibration Sensitive Land Uses Land uses in which ground-borne vibration could potentially interfere with operations or equipment, such as research, manufacturing, hospitals, and university research operations are considered vibration sensitive. The degree of sensitivity depends on the specific equipment that would be affected by the ground-borne vibration. As with noise, three categories are typically used to differentiate the sensitivity to ground-borne vibration according to FTA guidelines; these are Category 1 (buildings where vibration would interfere with interior operations), Category 2 (residences and buildings where people normally sleep), and Category 3 (institutional land uses with primarily daytime use) land uses as defined in Section 4.4.1 in more detail. As mentioned previously, some building types can be very sensitive to vibration and noise, but that do not fit into any of the three described categories (e.g., fragile historic structures, concert halls, television and recording studios, and theaters). Such facilities usually warrant special consideration during assessment of noise and vibration effects; however, no such facilities were identified in the vicinity of the Proposed Action. Vibration-sensitive land uses along the project limits consist of residential (Category 2) uses (refer to Table 4.4-1). There are no known Category 1 land uses along the project limits; additionally, while there are commercial and industrial land uses in this area, they are not generally considered vibration sensitive. Noise and Vibration Measurements Noise and vibration measurements were conducted in 2013 at four locations near the existing rail tracks, shown on Figure 4.4-4, Measurement Locations, and described below. ML-1 (noise: passenger and freight): located in Solana Beach at the northwest corner of

the large parking lot at the intersection of South Cedros Avenue and Cofair Avenue. At the ML-1 position along the alignment, the measurement was taken at approximately 70 feet from the closest track.


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ML-2 (vibration: freight): located off of Jimmy Durante Boulevard, east of the railroad tracks and west of the Del Mar Public Works Department yard. At the ML-2 position along the alignment, measurements were taken at approximately 50 feet from the closest track and at approximately 100 feet from the closest track; two measurements were conducted in order to provide more comprehensive data. Note that 100 feet is the approximate distance to the nearest residential property line.

ML-3 (noise: passenger and freight): located west of the tracks and east of the cul-de-sac at 21st Street. At the ML-3 position along the alignment, measurements were taken at approximately 90 feet from the closest track. Note that 90 feet is the approximate distance to the nearest residential property line.

ML-4 (vibration: passenger): located immediately north of the Solana Beach train station (just north of the northern project limits) in the small landscaped area associated with the Solana Beach Visitors Center. At the ML-4 position along the alignment, measurements were taken at approximately 75 feet and 90 feet east of the existing tracks.

The measurement locations were chosen based on different topographic conditions along the rail alignment or at the approximate distance to the nearest receptor. Locations ML-1 and ML-3 were chosen for noise measurements because they represented different acoustic conditions located north and south of Via de la Valle (depressed rail track at ML-1 and at-grade rail track at ML-3). Locations ML-2 and ML-4 represent different soil conditions that would affect vibration levels. Locations were also dependent on site accessibility; for example, ML-4, though located north of the project limits, represented vibration conditions that were similar to those south of Lomas Santa Fe Drive and was more accessible for a measurement. The long-term noise and vibration measurements were recorded by meters that were unattended after the initial set-up. However, trains were observed during daytime site reconnaissance to note the general configuration of trains that were passing by. Train pass-bys included Amtrak Surfliners and NCTD COASTER passenger trains. The trains were traveling both northbound and southbound, and were oriented in both pulling and pushing (locomotive was located in the front of the other train cars, or locomotive located behind the cars, respectively) configurations. The trains viewed during the measurements were mostly comprised of four cars with a single locomotive, but some trains with up to six cars and two locomotives were noted. Long-term noise measurements (two measurements at each site that were 24 hours in duration) were taken at location ML-1 (70 feet from railroad tracks) and at ML-3, as described above (90 feet from nearest track). The long-term measurements captured both passenger (daytime) and freight (nighttime) train pass-by events. Typical hourly average maximum noise levels at ML-1 were in the approximate range of 58 dBA to 59 dBA. The 24-hour average noise levels at ML-1 were 54.0 LDN and 52.7 LDN for the two long-term measurements at this site. Noise levels at this location take into account the acoustic shielding that occurs because the rail tracks are located below grade (trench).



Typical hourly average maximum noise levels at the ML-3 measurement location were approximately 65 dBA to 66 dBA. The 24-hour average noise levels at this measurement location were 64.0 LDN and 65.3 LDN for the two long-term measurements at this site. Freight train vibration measurements were taken at ML-2 at distances of 50 feet and 100 feet east of the existing railroad tracks. The measured vibration levels were 95.1 VdB at 50 feet and 90.4 Vdb at 100 feet. The vibration measurements were substantially higher than would typically be expected at a similarly configured railroad; this is potentially due to saturation of the sand with salt water within 15 feet of the surface, which amplifies vibration. Passenger train vibration measurements were taken at ML-4 near the Solana Beach Visitors Center (just north of the Solana Beach train station). The two vibration meters were located at 75 feet and 90 feet east of the existing railroad track. The maximum one-second vibration levels were 68.2 VdB and 62.9 VdB. Noise and Vibration Models Construction noise estimates were modeled using the FHWA Roadway Construction Noise Model, as it is the recommended model discussed in the FTA guidelines. With regard to construction vibration, calculations were based on standard procedures and estimates for construction equipment and operations provided by SANDAG. Existing and future operational rail noise estimates are based on the FRA CREATE Rail Noise Model (spreadsheet by Harris Miller Miller and Hanson, Inc. 2006) and the Computer-Aided Noise Abatement (CADNA) model, Version 3.5. The CREATE railroad noise model allows input of up to eight different types of noise sources, the activity of these noise sources, and noise-sensitive receptor data to calculate hourly-equivalent (LEQ) or day-night (LDN) noise levels. The model is based on the FTA General Transit Noise Assessment spreadsheet including moving and stationary railroad and highway noise sources. The CADNA model predicts noise impacts in a wide variety of conditions. It allows for consideration of effects from a variety of variables (including noise source, intervening structures, and topography) in estimating sound levels at a particular location. The modeled noise levels for these analyses are closely correlated with the measured noise levels, with a variance of approximately 1 dBA LEQ, which shows that the models provide good estimates of real noise levels. Analysis for the Proposed Action was based on the modeled levels for reasonable worst-case assessment. Construction vibration calculations are based on standard procedures and estimates for construction equipment and operations provided in the FTA guidelines. Noise & Vibration Work (NWWin), Software for Acoustic & Vibration, Measurement and Reports software was used to analyze vibration impacts for rail operation. Construction Modeling Assumptions Construction assumptions used for the noise and vibration analysis are based on the phasing and activities described in Section 3 of this EA. The worst-case construction noise analysis for rail improvements assumed the simultaneous use of an excavator, loader, and a dump truck. Due to



the noise shielding provided by the edge of slope (the trench segment is approximately 20-25 feet below grade) for Segment 1, a 5-decibel noise reduction was assumed for construction activities occurring in the trench. Modeling for construction activities for the rail improvements was based on a worst-case distance of 60 feet to the nearest residence in Segment 1, 70 feet to the nearest residence in Segment 2, and 50 feet to the nearest residence in Segment 3 South. These distances are based on approximate distance between the location of construction equipment and/or staging area and the nearest residences. The distances will vary as construction equipment moves along the corridor. The excavator (the loudest source) was assumed as the closest piece of equipment, and an additional distance of 20 feet to the loader and dump truck was incorporated into the analysis. To provide a conservative analysis, it is assumed the equipment is running continuously for eight hours. During the bridge and platform construction, the loudest pieces of equipment would be the vibratory pile driver. These operations typically include a large crane and a mobile crane (or loader used as a crane), as well as a generator to run the vibratory pile driver and truck for the piling delivery. The closest location for these operations is approximately 190 feet east of the nearest residence. Nighttime construction analysis assumes two cranes and an idling locomotive engine during the installation of the precast girders. It includes the noise from a slow speed pass-by of the bridge delivery train shuttling to a siding to allow normal freight train passage. The closest residence to this activity would be 435 feet. Construction of the Stevens Creek culvert would be similar to other portions of the construction including the use of excavators, cranes, loaders, materials import and export. It would include the use of vibratory piling installation of H-beams to support the culvert structure. The closest receptor to proposed areas of construction of the culvert is at a distance of approximately 290 feet. The highest levels of construction-related vibration during construction of the rail improvements would be associated with a vibratory roller. The closest receptor distance to the vibratory roller is assumed to be 65 feet, based on the anticipated construction footprint. The highest levels of vibration from the platform construction would be from the vibratory pile driving equipment, the closest of which would be located 190 feet from the nearest residence. Operational Modeling Assumptions Where appropriate, the existing topography and the segment-specific rail alignment grade were incorporated into the noise modeling. Assumptions included for existing and future train modeling include the following: All passenger train modeling is based on a single (in operation) locomotive and five cars

traveling at 70 mph.

All freight train modeling is based on 5 locomotives and 80 cars traveling at 50 mph.



The average length for locomotives is 69 feet; the average length for passenger rail cars is 85 feet and 60 feet for freight rail cars.

Although some passenger trains have two locomotives; only one locomotive is assumed to be providing power.

All rails will be welded (one piece) on new cement ties. Rail Operations Assumptions Existing and future passenger and freight train operations incorporated into the noise and vibration models are listed in Table 4.4-5, Existing and Future Passenger and Freight Train Operations, below. Under the No Action Alternative, train operations would not exceed 2020 levels due to the limited capacity of the existing track.

Table 4.4-5 EXISTING AND FUTURE PASSENGER AND FREIGHT TRAIN OPERATIONS

Time of Day Existing 2020 2025 2030

Passenger Freight Passenger Freight Passenger Freight Passenger Freight Day 35 0 44 0 54 0 71 0 Night 9 6 12 11 14 11 19 11

TOTAL 50 67 79 101 Source: HELIX 2014b (Appendix C). During the horse racing season and potentially during the San Diego County Fair, Amtrak would run one 10-car special events train each day (i.e., two train trips). Modeling assumed that the train would depart from Union Station in Los Angeles, drop off passengers at the proposed Del Mar Fairgrounds platform, and then head to Santa Fe Depot downtown where it would be staged until that evening’s return trip to Los Angeles. This daily special events train was included in the modeling for the Action Alternatives. Additionally, although the number of daily train meets1 is expected to increase under future conditions, trains were analyzed in the worst-case condition, without consideration of slower speeds due to train meets. Rail Alignment Assumptions. The closest homes to the existing rail along Segments 1, 2, and 3 South are located between 50 and 100 feet from the rail track. The rail track in Segment 1 is below grade (20 to 25 feet) compared to the ground level of the residences, and as a result, these residences experience some natural shielding. The rail tracks within Segment 2 and Segments 3 Central and South are considered to be at the same ground level as the surrounding land uses. The proposed alignment for Segment 3 North may be higher than the existing rail by up to eight feet; however, this change in elevation is not expected to measurably affect train noise

1 Train meets are instances where a northbound and southbound train pass by each other in opposite directions.



levels because the existing track in this area presently lies above grade compared to surrounding structures and has an unobstructed line of sight to the nearest residences. Under each of the action alternatives, Segments 1, 2, and 3 South would construct new tracks at a lower vertical grade relative to the existing condition (one to two feet lower). The new eastern track would be constructed close to the proposed retaining wall. The modifications in the grade and proximity to the wall are expected to provide two to four dBA of noise shielding as compared to an at-grade track with no retaining wall; estimates are based on two dBA of shielding for conservative analysis. In addition to the aforementioned vertical grade differences, the existing and proposed rail alignment shifts slightly to the east or west throughout the corridor, and the separation distance between the existing and proposed east and west tracks is not uniform. Therefore, within Segments 1 and 3 estimated noise levels are provided for sub-segments to account for the variation in track separation, and variation in proximity of the closest track (whether east or west side) to a sensitive noise receptor. Rail Platform Noise Assumptions. There are essentially three potential noise sources associated with the platform: (1) trains (including train braking, idling locomotive engines, and accelerating locomotive engines), (2) human speech/communications on the platform, and (3) public address systems. The special events platform would not typically result in the use of train horns, so the potential for horn noise is not considered to be a potential noise source. It is assumed that the proposed platform would only be used when there are special events at the Del Mar Fairgrounds. Two methods of assessment were used to evaluate potential estimation of future noise from the special events platform that would be constructed in the three action alternatives. The initial screening is based on the procedure provided by FTA in Chapter 4 of the Transit Noise and Vibration Impact Assessment (FTA 2006). Data used in the screening assumptions are based on operations of a given type of project listed in Table 4-1 in the FTA guidelines and use a noise level of 50 dBA LDN to establish the screening distance. If no noise-sensitive land uses are located within the screening distance, then no further analysis is needed. In utilizing the screening table, the project category listed in Table 4-1 that was most analogous in use to the proposed platform was the rail rapid transit station. A more detailed analysis based on individual noise sources was also conducted. This analysis is based on noise measurements of two separate engines idling at the Solana Beach station. To ensure the measured levels were representative of a worst-case noise level, these measurements were taken above the engines, along the side of the station, with a clear and direct view of the engine exhaust. The average of the measured noise levels for idling trains was 66 dBA at 50 feet. Noise measurements were also taken when the same engines pulled out of the station. The average of the measured noise levels for trains pulling out of the station was 72.5 dBA (maximum) at 50 feet over a three second interval. Both of these noise levels would be at least 4 dBA lower at distances of 100 feet. The noise generated by the train pulling out of the station (the louder of the two sources mentioned) from a distance of 100 feet would be very similar to the maximum pass-by



noise level measured for a single train; the duration of the noise event would also be similar to that of a train pass-by noise event, as both would last only a few seconds. To determine a worst-case noise level caused by the idling trains, five trains were assumed to be idling for five minutes each in the span of one hour. With regard to brake squeal, few occurrences of brake squeal were noted while measurements were conducted at the Solana Beach station; when brake squeal did occur, the duration of the event was short (a few seconds). Therefore, brake squeal would not measurably contribute to overall noise impacts associated with the special events platform. With regard to crowd noise, the noise level generated by human speech ranges from 55 dBA to 65 dBA at a distance of 5 feet. Assuming the number of people on the special events platform at a given time would be equivalent to a fully loaded 10-car passenger train (with each car carrying up to 90 passengers), the maximum number of people expected to be on a train platform at a given time would be approximately 900 individuals. A reasonable assumption is that at any given time, approximately 30 percent of these individuals (300 people) are talking in a moderate to loud voice with an approximate noise level of 65 dBA at 3 feet. A loud public address system speaker could create a noise level of approximately 85 dBA at 25 feet. Assuming that the public address system at the special events platform announced five departing trains in the span of an hour (assuming a worst-case of one minute for each announcement), this would lead to an hourly noise level of 74.2 dBA LEQ at 25 feet. 4.4.3 Environmental Consequences The following analysis evaluates potential noise and vibration impacts resulting from construction and operation of the Action Alternatives and the No Action Alternative of the Proposed Action. The construction analysis addresses installation of the new double-track bridge structures, track improvements including addition of double track, construction of the special events platform, and other rail improvements and modifications. The operational analysis addresses the changes in noise and vibration levels that would be expected from re-alignment of the track, installation of the double track, and other improvements along the rail corridor. Operational impacts also address potential noise resulting from the proposed rail platform, as well as the addition of special event train noise. The analysis includes existing (year 2013), year 2020, year 2025, and 2030 conditions with the Action Alternatives, as well as the No Action Alternative. It is important to note that the future No Action assumes that train operations will increase per Table 4.4-5, up to the year 2020, where operations will be constrained by the rail capacity and would no longer increase. Up to the year 2020, the primary difference affecting noise levels between the Action Alternatives and the No Action Alternative is due to the reconfiguration of the track, the installation of retaining walls, and the special events train and platform.



East Side-Loading Alternative Construction Impacts Construction for Segment 1 (North and South), Segment 2 and Segment 3 South would take place closer to residences than would construction in Segment 3 North and Segment 3 Central. Accordingly, the construction noise and vibration analyses conducted for Segments 1 (North and South), 2, and 3 South are representative of the worst-case construction noise and vibration condition for all rail segments. Segments 1 (North and South), 2, and 3 South would involve the same rail improvements and rail configuration, and would also lead to the same potential noise and vibration effects associated with operation for any of the Action Alternatives. Noise – Double Track Rail Construction The noise levels from construction equipment would vary greatly depending on factors such as the type of equipment (mobile versus stationary), the specific equipment model, the operation being performed, and the condition of the equipment. The noise level also depends on the duration of time that the equipment is used. Construction equipment noise comes from a variety of sources including the engine casing radiation noise, engine exhaust, and cooling fan as well as the equipment operational noise which may include track squeal, backup alarms, and ground engaging tool noise as well as other sources such as bucket shakeouts. The dominant construction noise in Segments 1, 2, and 3 South (which, as noted above, represent the worst-case construction noise and vibration condition because receptors are located in closest proximity compared to the other segments where double track would be installed) is expected to come from general excavation of soils required for the track installation in these areas and from construction of a retaining wall (Segment 1 only). As previously noted, the worst-case construction noise analysis assumed the simultaneous use of an excavator, loader, and dump truck to the east of the tracks (which is the closest location to residential uses). Due to the noise shielding provided by the edge of slope (20 to 25 feet) for Segment 1, a 5-dBA noise reduction was assumed in the analysis. The closest residence to proposed areas of construction is located at a distance of 60 feet in Segment 1, 70 feet in Segment 2, and 50 feet in Segment 3 South. The excavator (the loudest source) was assumed to be the closest piece of equipment to the receptor, and an additional distance of 20 feet from the excavator was assumed for the loader and dump truck. The estimated worst-case construction-noise levels resulting from the proposed rail improvements are based on the aforementioned equipment in simultaneous operation (running continuously for an eight-hour period); the estimated noise level at the nearest residence is 76 dBA LEQ for Segment 1 (at 60 feet), 72 dBA LEQ for Segment 2 (at 70 feet), and 79 dBA LEQ for Segment 3 (at 50 feet). These levels do not exceed the daytime impact criterion of 80 dBA LEQ (8h), as identified in Table 4.4-3. Therefore, the noise impacts related to construction of the rail improvements during daytime hours are not expected to be adverse.



Nighttime construction would be similar to daytime construction with the potential similar construction noise impacts, with noise levels ranging from 79 dBA at 50 feet to 72 dBA at 70 feet. All of these noise levels exceed the nighttime criterion of 70 dBA LEQ (8-hour). Therefore, the nighttime noise impacts related to rail alignment construction are expected to be adverse. Noise – Bridge and Platform Construction The loudest bridge and platform construction noise would occur during the vibratory pile driving. These operations typically include a large crane and a mobile crane (or loader used as a crane), as well as a generator to run the vibratory pile driver and truck for the piling delivery. The closest location for these operations is approximately 190 feet east of the nearest residence. The expected noise from the vibratory pile driver at this distance is 82 dBA LEQ (8-hour; assuming that the equipment is running continuously for an 8-hour period). Other construction equipment would be expected to contribute to a lesser extent than the pile driver at noise levels of approximately 70 dBA LEQ (8-hour) of noise, leading to a total expected noise level from all operating equipment of 82 dBA LEQ (8-hour). This would exceed the 80 dBA LEQ (8-hour) impact criterion at residential areas during daytime hours (refer to Table 4.4-3), and thus, would be expected to result in an adverse construction noise impact to nearby residents. Refer to Figures 4.4-5a and 4.4-5b, Areas with Potential Noise and Vibration Impacts, for locations that would be expected to have potentially adverse construction noise and vibration impacts. As indicated on these figures, approximately 13 single-family residences between 26th and 28th Streets, a multi-family building north of 28th Street, along with a single-family residence located east of the tracks and immediately south of Via de la Valle would experience these potentially adverse construction noise levels. Nighttime construction analysis assumes two cranes and an idling locomotive engine during the installation of the precast girders. It includes the noise from a slow speed pass-by of the bridge delivery train shuttling to a siding to allow normal freight train passage. The closest residence to this activity would be 435 feet. The crane noise would be approximately 57 dBA LEQ (8-hour) at the closest residence and the single freight train pass-by at 10 mph would be 45 dBA LEQ (8-hour) with a total 57 dBA LEQ (8-hour) at the closest residence. These levels do not exceed the impact criterion of 70 dBA LEQ (8-hour). Therefore, the noise impacts are not expected to be adverse for the nighttime construction installation of prefabricated beams at the bridge and station platform. Noise – Stevens Creek Culvert The Stevens Creek Culvert would be similar to other portions of the construction including the use of excavators, cranes, loaders, materials import and export. It would include the use of vibratory piling installation of H-beams to support the culvert structure. The closest receptor to proposed areas of construction is located at a distance of approximately 290 feet. The excavator (the loudest source) was assumed to be the closest piece of equipment to the receptor, and an additional distance of 20 feet from the excavator was assumed for the loader and


Via De La Valle

Camino Del Mar

Solar Circle Drive

City of Del Mar

City ofSolana Beach

Del Mar Fairgrounds

S t e v e n s C r e e k



Figure 4.4-5a

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Areas with Potentially Adverse DaytimeConstruction Noise and VibrationImpacts for All Action AlternativesAreas with Potential Impactsfor East Side-Loading andEast Center-Loading AlternativesAreas with Potential Impactsfor West Side-Loading AlternativeAreas with Potential Impactsfor All Action AlternativesSegment 3 NorthSegment 3 CentralSegment 3 South

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dump truck. The estimated worst-case construction-noise levels resulting from the proposed rail improvements are based on the aforementioned equipment in simultaneous operation (running continuously for an eight-hour period); the estimated noise level is 62 dBA LEQ for the Stevens Creek Culvert. These levels do not exceed the daytime impact criterion of 80 dBA LEQ (8-hour). Therefore, the noise impacts related to alignment construction are not expected to be adverse for the Stevens Creek Culvert. Vibration – Double Track Rail Construction The highest levels of construction-related vibration in these areas would be associated with a vibratory roller, which creates a vibration level of 94 VdB at 25 feet. At a distance of 165 feet, which is the approximate closest distance to a residence, this level would be expected to reduce to 69 VdB. Vibratory rollers operate at slow speeds and do not pass by the same location more than a few times a day; therefore the threshold used for vibratory rollers is for infrequent events. The impact level used for Category 2 land uses (residences) as listed in Table 4.4-4 is 80 VdB for infrequent events. Therefore, construction vibration impacts related to double track alignment construction would not exceed the impact criterion, and no associated adverse impacts would occur. Vibration – Bridge and Platform Construction The greatest construction vibration effects associated with bridge and platform construction would be caused by a vibratory pile driver, which has a maximum vibration level of 105 VdB (maximum) at 25 feet. At a distance of 190 feet, the maximum vibration level at the nearest residence would be 79 VdB. Due to the nature of a vibratory pile driver, this activity is assumed to have many events in a given period, therefore the criteria used is for frequent events. Given this range, it is reasonable to expect that vibration from bridge and platform construction would exceed the impact criterion (72 VdB for frequent events), depending on the frequency and power of the driver. As noted previously, exceeding 72 VdB (for frequent events) at residential areas is likely to cause an adverse community reaction. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. As noted above, approximately 13 single-family residences and a multi-family building would experience these potentially adverse construction noise and vibration levels. Vibration - Stevens Creek Culvert Supports for the Stevens Creek culvert would be installed using a vibratory pile driver. The closest distance to a residence is 290 feet. At this distance, the vibratory pile driver would result in a maximum level of 73 VdB, which would exceed the threshold of 72 VdB for frequent events. An adverse construction impact would occur. Operational Impacts Segment 1 North, Segment 1 South, Segment 2, and Segment 3 South would have the same alignment under each of the Action Alternatives. The noise and vibration analysis for Segment 1 North, Segment 1 South, Segment 2, and Segment 3 South is, consequently, the same for all



Action Alternatives. Thus, the analysis for these segments is grouped together. Additionally, the proposed alignment for Segment 3 North and Segment 3 Central differs with each Action Alternative; consequently, the analysis for these segments is also grouped together. Noise – Rail Noise Segments 1 (North and South), Segment 2, and Segment 3 South. Table 4.4-6, Modifications of Rail Track Centerline From Existing Alignment - Segments 1 (North and South), Segment 2, and Segment 3 South, identifies the offset distance for the proposed realignment of the eastern or western railroad tracks from the existing track for Segments 1 (North and South), Segment 2, and Segment 3 South. As mentioned above, Segment 1 North, Segment 1 South, Segment 2, and Segment 3 South would have the same alignment under each of the Action Alternatives, and thus, the corresponding offsets would be the same. As the noise and vibration analysis for Segment 1 North, Segment 1 South, Segment 2, and Segment 3 South is the same for all Action Alternatives, the analysis for these segments will be fully discussed in this section (for the East Side-Loading Alternative), but will not be discussed in detail for the other Action Alternatives. The discussion of impacts to these segments for the other action alternatives will refer back to the discussion in this section because the impacts would be the same.

Table 4.4-6 MODIFICATIONS OF RAIL TRACK CENTERLINE FROM EXISTING

ALIGNMENT - SEGMENTS 1 (NORTH AND SOUTH), SEGMENT 2, AND SEGMENT 3 SOUTH

All Action Alternatives

Segment West Track East Track Segment 1 North 9 feet west 9 feet east Segment 1 South 19 feet west 2.5 feet east Segment 2 (North and South) 26 feet west no change Segment 3 South 3 feet west 17 feet east Source: HELIX 2014b. (Appendix C).

The closest residences to the existing rail in Segments 1 (North and South) and 2 are located between 75 and 100 feet from the rail track. Segment 3 South includes residences at distances of approximately 50 feet from the existing track. Along Segment 1 North, noise modeling results project that noise levels would decrease by approximately 1 dBA when comparing this alternative to the future No Action (baseline) scenario under all existing and future scenarios (years 2020, 2025, and 2030); this would apply to the residences on the eastern side of the tracks at distances between 75 feet and 100 feet. As a result, no operational noise impacts would occur within Segment 1 North under the East Side-Loading Alternative.



Along Segment 1 South, noise levels are projected to decrease between 1 to 2 dBA at distances of 75 feet and 100 feet on the eastern side of the tracks, with implementation of this alternative under all future scenarios (years 2020, 2025, and 2030) compared to No Action Alternative. This is due to the shifting of the western track 19 feet to the west, and to the change in height of the eastern track (lowering the grade). Additionally, the eastern track would be located close to a proposed retaining wall, which would provide additional shielding. As a result, no operational noise impacts would occur within Segment 1 South under the East Side-Loading Alternative. Similarly, rail noise levels at residences along the eastern side of Segment 2 would decrease by approximately 1 dBA because of the shifting of the track 26 feet to the west. As a result, no operational noise impacts would occur within Segment 2 under the East Side-Loading Alternative. For the Segment 3 South rail section on the western side of the tracks, there would be no discernible change in the estimated noise levels. However, for the residences located along the eastern side of the tracks, estimated noise levels would increase by 1 dBA in all future scenarios (years 2020, 2025, and 2030) with this alternative compared to the No Action Alternative at 75 feet and 100 feet. More specifically, this increase would occur at up to approximately one dozen single-family residences and one multi-family building along Grand Avenue, east of the tracks and south of the Camino Del Mar overcrossing. The increase is primarily due to the eastern track shifting 17 feet further to the east (closer to the residences). According to FTA criteria (refer to Figure 4.4-3), because the baseline is above 70 decibels, the increase of one decibel would be considered a “Moderate Impact.” Table 4.4-7, Summary of Moderate Operational Noise Impacts, on the following page provides a summary of expected moderate operational noise impacts.



Table 4.4-7

SUMMARY OF MODERATE OPERATIONAL NOISE IMPACTS

Segment 3 South – All Action Alternatives East of Railroad

Distance from Rail

Tracks (ft)

Existing (LDN) 2020 (LDN) 2025 (LDN) 2030 (LDN)

Existing Proposed Action

Change Impact No

Action Proposed

Action Change Impact

No Action

Proposed Action

Change Impact No

Action Proposed


75 73 73 0 N 75 76 1 M 75 76 1 M 75 76 1 M 100 71 71 0 N 73 74 1 M 73 74 1 M 73 74 1 M

Segment 3 Central – East Side-Loading Alternative East of Railroad

Distance from Rail

Tracks (ft)



Change Impact No

Action Proposed


No Action

Proposed Action

Change Impact No

Action Proposed


150 70 71 1 N 71 72 1 M 71 72 1 M 71 72 1 M Segment 3 Central – East Center-Loading Alternative

East of Railroad Distance

from Rail

Tracks (ft)



Change Impact No

Action Proposed


No Action

Proposed Action

Change Impact No

Action Proposed


150 70 71 1 N 71 72 1 M 71 72 1 M 71 72 1 M



Table 4.4-7 (cont.)

SUMMARY OF MODERATE OPERATIONAL NOISE IMPACTS

Segment 3 North – West Side-Loading Alternative West of Railroad

Distance from Rail

Tracks (ft)



Change Impact No

Action Proposed


No Action

Proposed Action

Change Impact No

Action Proposed


75 74 76 2 M 75 77 2 M 75 77 2 M 75 77 2 M 100 73 74 1 M 73 75 2 M 73 75 2 M 73 75 2 M 125 71 72 1 M 72 73 1 M 72 73 1 M 72 73 1 M 150 70 71 1 N 71 72 1 M 71 72 1 M 71 72 1 M

Segment 3 Central – West Side-Loading Alternative West of Railroad

Distance from Rail

Tracks (ft)



Change Impact No

Action Proposed


No Action

Proposed Action

Change Impact No

Action Proposed


75 74 76 2 M 75 77 2 M 75 77 2 M 75 77 2 M 100 73 74 1 M 73 74 1 M 73 74 1 M 73 75 2 M 125 71 72 1 M 72 73 1 M 72 73 1 M 72 73 1 M 150 70 70 0 N 71 71 0 N 71 72 1 M 71 72 1 M

N = No Impact, S = Severe Impact, M = Moderate Impact Source: HELIX 2014b (Appendix C).



Segment 3 North and Central. These noise and vibration analysis segments would not have the same alignment under each of the Action Alternatives, and thus, the offsets differ for each analyzed action alternative. Table 4.4-8, Modifications of Rail Track Centerline From Existing Alignment - Segments 3 North and Central, shows the offset distances for the relocation of the eastern and western railroad tracks in relation to the existing track for Segment 3 North and Central with implementation of the East Side-Loading Alternative.

Table 4.4-8 MODIFICATIONS OF RAIL TRACK CENTERLINE

FROM EXISTING ALIGNMENT – SEGMENTS 3 NORTH AND CENTRAL

East Side-Loading Alternative

Segment West Track East Track Segment 3 North 29 feet east 50 feet east Segment 3 Central 14 feet east 30 feet east Source: HELIX 2014b (Appendix C).

Under the East Side-Loading Alternative, residential noise exposure from rail operations would decrease by 1 to 3 dBA along the western side of Segment 3 North compared to the No Action Alternative in the years 2020, 2025, and 2030. No operational noise impacts would occur within Segment 3 North. Along Segment 3 Central on the eastern side of the tracks, the nearest residences are located at distances between 150 feet and 200 feet. At these distances, the increase for this alternative compared to the future baseline in 2020, 2025, and 2030 would be 1 dBA. Based on FTA noise impact criteria, this increase is considered a moderate impact. Along Segment 3 Central on the western side of the tracks, noise levels would decrease by approximately 1 dBA. Based on the FTA noise impact criteria (refer to Figure 4.4-3), no operational noise impacts would occur to residents on the west side of the tracks along this segment under the East Side-Loading Alternative. Noise – Platform Passenger Noise The FTA screening distance for a train passenger platform is 200 feet for an adverse noise impact, and the closest residences to the proposed Del Mar Fairgrounds Special Events Platform would be approximately 435 feet away (south of the platform, across the San Dieguito River). Accordingly, the FTA guidance indicates that a detailed evaluation of noise impacts from the proposed platform is not required for these residences; however, because the issue of platform-related noise has been raised as a community concern, additional analysis was conducted to assess potential noise impacts resulting from noise generated by patrons using the proposed rail platforms.



The FTA guidance states that in order for the platform passenger noise level to be less than adverse, it must be below the threshold of 50 dBA at the noise sensitive receiver, which is the lowest threshold outlined for noise sensitive uses in the guidelines. There are essentially three potential noise sources associated with the platform: (1) trains (including train braking, idling locomotive engines, and accelerating locomotive engines), (2) human speech/communications on the platform, and (3) public address (PA) systems. Although a public address system is not currently proposed for regular use at the special events platform, it is possible that one would be provided for safety reasons; thus, this analysis conservatively assumes that a PA system would be in use. As noted under the Existing Noise Environment subheading of Section 4.4.2 of this EA, noise levels of two separate engines idling at the Solana Beach Station, as well as pulling out of the station, were measured to determine the contribution of train-related noise sources to overall platform-related noise effect. The average of the measured noise levels for idling trains was 66 dBA at 50 feet. The average of the measured noise levels for trains pulling out of the station was 72.5 dBA (maximum) at 50 feet over a 3-second interval. Noise levels would be at least 4 dBA lower at distances of 100 feet. Noise levels at the closest residence from the proposed platform would be expected to be approximately 40.1 dBA LEQ. The noise level at the closest residence from the acceleration of these trains leaving the proposed platform would be 43.1 dBA LEQ. Crowds on the platform would generate a noise level at the closest residence of approximately 37.6 dBA. If this noise level was generated by platform crowd noise for 15 minutes per hour, the hourly average would be 31.6 dBA LEQ at the nearest residence. A PA system could create a noise level of approximately 85 dBA at 25 feet. If there were two PA speakers at this level, this would equate to an approximate hourly noise level of 40.8 dBA LEQ at the nearest residence. When all of these noise sources are considered together, the modeled noise level at the nearest residence is 47 dBA LEQ. This noise level would not be considered an impact pursuant to FTA guidance, as it would not be above the threshold of 50 dBA (which is the lowest threshold outlined for noise sensitive uses in the guidelines); thus, it is within the outdoor noise level range considered acceptable for residential areas. Vibration Segment 1 (North and South), Segment 2, and Segment 3 South. Table 4.4-9, Changes in Operational Vibration Levels for a Single Pass-by Event (All Future Scenarios) - Segments 1 (North and South), Segment 2, and Segment 3 South, below presents the changes in the vibration level of a single train pass-by under any future scenario for the Segments 1 (North and South), Segment 2, and Segment 3 South with the East Side-Loading Alternative. For these segments, the proposed alignment is comparable for all of the potential Action Alternatives proposed. These changes would be due to the alignment modifications involved with the Proposed Action. Vibration levels for a single pass-by event within Segments 3 North and South use the same vibration assumptions. The actual soil conditions, however, are slightly different and vibration



levels in Segment 3 North are expected to be lower. As shown in Table 4.4-9, the East Side-Loading Alternative would result in increases in ground-borne vibration. However, the resulting vibration levels would remain below the FTA’s ground-borne vibration impact criterion for Category 2 land uses (72 VdB for frequent events). Therefore, operational vibration impacts within Segment 1 (North and South), Segment 2, and Segment 3 South would not be considered adverse.

Table 4.4-9 CHANGES IN OPERATIONAL VIBRATION LEVELS FOR A

SINGLE PASS-BY EVENT (ALL FUTURE SCENARIOS) – SEGMENTS 1 (NORTH AND SOUTH), SEGMENT 2, AND

SEGMENT 3 SOUTH

All Action Alternatives Vibration in VdB re 10 -6 ips

Location Land Use Existing Proposed


Segment 1 North East Residential 62.9 68.2 5.3 N

Segment 1 South East Residential 62.9 68.2 5.3 N

Segment 2 East Residential 88.6 88.6 0.0 N

Segment 3 South East Residential 90.3 91.5 1.3 N West Residential 94.5 94.9 0.4 N

N= No Impact ips = inches per second Source: HELIX 2014b (Appendix C).

Segments 3 North and Central. The proposed railroad track would be on a new raised bed to connect to the future elevated bridge structure in most of Segments 3 North and 3 Central. Actual vibration impacts are expected to be slightly lower than those predicted in this analysis due to the new elevation (which would provide some barrier shielding effect from the vibration), and due to the slight additional distance that vibration must travel because of this elevation change. The benefits related to vibration reduction taper to the south, as the railroad track elevation decreases to the original grade. This analysis does not include any attenuation effects due to this grade modification in order to provide a worst-case assessment. Table 4.4-10, Changes in Vibration Levels – Segment 3 North and Segment 3 Central, presents the existing vibration level for a single pass-by event along with the change of vibration levels of a single pass-by event for the closest potentially affected structures along Segment 3 North and Segment 3 Central for the East Side-Loading Alternative (all future scenarios). This alternative would not exceed the threshold criterion for vibration impacts (an increase of 3 VdB for areas



that already exceed the impact levels) in Segment 3 North or Segment 3 Central. Therefore, operational vibration impacts within Segment 3 North or Segment 3 Central would not be considered adverse.

Table 4.4-10 CHANGES IN VIBRATION LEVELS –

SEGMENT 3 NORTH AND SEGMENT 3 CENTRAL

East Side-Loading Alternative Vibration in VdB re 10 -6 ips

Location Land Use Existing Project Change Impact

Segment 3 North West Residential 86.2 87.4 1.2 N

Segment 3 Central East Residential 86.2 87.4 1.2 N West Residential 90.4 89.5 -0.9 N

N= No Impact ips = inches per second Note: Commercial uses in this section would increase approximately 3.1 to 3.5 VdB; however, these uses are not vibration sensitive. Source: HELIX 2014b (Appendix C).

Summary of East Side-Loading Alternative Noise and Vibration Impacts Construction of the East Side-Loading Alternative would generate noise and vibration at or above levels established by the FTA as being likely to cause an adverse community reaction (i.e., at some points during the approximately three-year construction period, construction noise levels would be annoyingly loud, and vibration annoyingly noticeable, to some residents near the tracks). More specifically, residents located west of the railroad tracks to the south of the San Dieguito River would likely experience an adverse reaction during construction of the new bridges over the San Dieguito River, especially during the pile-driving stage of construction. Similarly, residences east of the tracks just south of Via de la Valle would experience an adverse reaction during pile driving associated with the realignment of Stevens Creek under the railroad embankment in that area. Additionally, nighttime construction activities associated construction of double track could result in adverse impacts to residences along the project limits. These adverse impacts are not assessed as being substantial under NEPA because of the limited number of residences affected, the temporary duration of the loudest generator of noise impacts (i.e., pile driving), and the limited amount of nighttime construction that would occur. Although not required to avoid a substantial impact, Section 4.4.4 describes avoidance, minimization, and mitigation measures that could be used to reduce construction noise. Following the completion of construction, the continuing increase in train operation levels, coupled with the new alignment of the railroad tracks, would generate noise level increases at some residences along the railroad tracks of approximately 1 dBA. More specifically, south of



the Camino Del Mar overcrossing and east of the tracks along Grand Avenue, this 1-dBA increase would affect approximately a dozen single-family homes and one multi-family building. Noise levels would also increase by 1 dBA at two single-family homes on the east side of the tracks, north of the Camino Del Mar overcrossing and east of Jimmy Durante Boulevard. A 1-dBA increase at residences compared to the No Action Alternative is near the FTA’s threshold between “No Impact” and “Moderate Impact” (see Figure 4.4-3). This approximately 1-dBA increase would not constitute a substantial impact under NEPA because of the relatively low number of residences affected and because a 1-dBA increase, which is barely perceptible to the average person, is at the lowest end of the range for a “Moderate Impact.” West Side-Loading Alternative Construction Impacts Noise – Double Track Rail Construction Noise impacts related to the double track construction for both daytime and nighttime work under the West Side-Loading Alternative would be the same as those identified above for the East Side-Loading Alternative. The estimated worst-case noise levels for construction equipment in simultaneous operation (running continuously for an 8-hour period) is 76 dBA LEQ for Segment 1, 72 dBA LEQ for Segment 2, and 79 dBA LEQ for Segment 3. These levels do not exceed the impact criterion of 80 dBA LEQ (8-hour), as identified in Table 4.4-3. Therefore, construction noise impacts related to the double track alignment during daytime hours construction are not expected to be adverse in Segments 1, 2, and 3 South. Nighttime noise impacts related to rail alignment construction, however, would be expected to be adverse. Noise – Bridge and Platform Construction Noise sources related to the bridge and platform construction for both the daytime and nighttime work would be the same as those described for the East Side-Loading Alternative. Daytime construction activities would exceed the impact criterion of 80 dBA LEQ (8-hour). Therefore, the noise impacts related to construction of the bridge and platform are expected to be adverse. Noise impacts are not expected to be adverse for the nighttime construction installation of prefabricated beams at the bridge and platform. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise impacts. Vibration – Double Track Rail Construction

Vibration impacts related to double track rail construction would be the same as those identified for the East Side-Loading Alternative. The highest levels of construction-related vibration would be associated with a vibratory roller, and would be expected to be approximately 69 VdB at the nearest residence. The impact level used for Category 2 land uses (residences) as listed in Table 4.4-4 is 80 VdB for infrequent events; as most construction actions occur fewer than 30 times per day in close proximity to a specific residential use, the infrequent events impact category for ground-borne vibration levels can be appropriately used here. Therefore, construction vibration impacts related to double track alignment construction would not exceed the impact criterion, and no associated adverse impacts would occur.



Vibration – Bridge and Platform Construction The greatest construction vibration effects associated with bridge and platform construction would be caused by a vibratory pile driver, which has a vibration level of 93 VdB (typical) to 105 VdB (maximum) at 25 feet. At a distance of 100 feet, the vibration level at the nearest residence would be expected to 87 VdB (maximum). Given this range, it is reasonable to expect that vibration from bridge and platform construction would exceed the impact criterion of 72 VdB for frequent events (refer to Table 4.4-4), depending on the frequency and power of the driver. As noted previously, exceeding 72 VdB (for frequent events) at residential areas would result in adverse construction vibration impacts. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. Operational Impacts Noise – Rail Noise Segment 1, Segment 2, and Segment 3 South. Operational noise impacts for Segment 1 (North and South), Segment 2, and Segment 3 South would be the same as identified for the East Side-Loading Alternative. No operational noise impacts would occur within Segment 1 North, Segment 1 South, or Segment 2. Operational noise impacts within Segment 3 South would be considered moderate under future conditions, however. As stated in the discussion for the East Side-Loading Alternative, estimated noise levels at the residences located along the eastern side of the tracks would increase by 1 dBA in all future scenarios (years 2020, 2025, and 2030). Future baseline (No Action) noise levels would increase from 73 dBA to 74 dBA at a distance of 75 feet, and from 71 dBA to 72 dBA at 100 feet. The increase is primarily due to the eastern track shifting 17 feet further to the east (closer to the residences). According to FTA criteria (refer to Figure 4.4-3), because the baseline is above 70 decibels, the increase of one decibel would be considered a “Moderate Impact.” Segments 3 North and Central. Table 4.4-11, Modifications of Rail Track Centerline From Existing Alignment - Segments 3 North and Central, shows the offset distances that the eastern and western railroad tracks would be relocated in relation to the existing track for Segments 3 North and Central under the West Side-Loading Alternative.

Table 4.4-11 MODIFICATIONS OF RAIL TRACK CENTERLINE FROM

EXISTING ALIGNMENT - SEGMENTS 3 NORTH AND CENTRAL

West Side-Loading Alternative

West Track East Track

Segment 3 North 29 feet West 8 feet West Segment 3 Central 20 feet West No Change Source: HELIX 2014b (Appendix C).



Noise exposure from rail operations on the western side of the rail tracks within Segment 3 North would increase by 2 dBA at a distance of 75 and by 1 dBA at distances between 100 and 125 feet under the future (2020, 2025, and 2030) scenarios. Because future baseline noise levels at these distances would range from 75 dBA at 75 feet to 71 dBA at 150 feet, increases of 1 dBA to 2 dBA would be considered a moderate impact per FTA criteria. This moderate increase in noise levels would affect up to approximately 25 single-family residences and one multi-family building located east of the tracks, south of the San Dieguito River, and north of 22nd Street. The nearest residences along Segment 3 Central are located at distances between 75 feet and 125 feet on the east side of the tracks. At these distances, noise levels for this alternative compared to the future baseline would remain unchanged or decrease by 1 dBA. However, on the western side of the rail tracks along the northernmost portion of Segment 3 Central, noise levels would increase at up to approximately four single-family residences between 21st and 22nd Streets. At a distance of 75 feet, the increase would be 2 dBA under this alternative in all scenarios compared to the No Action Alternative. These increases would be considered a moderate impact per FTA criteria. Refer to Table 4.4-7 for a summary of moderate operational noise impacts under this alternative. Noise – Rail Platform Noise Potential noise impacts related to the proposed rail platforms for this alternative would be the same as identified for the East Side-Loading Alternative. When considered together, the three potential noise sources associated with the platform noted above (including trains [braking, idling locomotive engines, and accelerating locomotive engines], human speech/communications on the platform, and potential PA systems) were modeled to have a noise level at the nearest residence of 47 dBA LEQ. This noise level would not be considered an impact pursuant to FTA guidance, as it would not be above the threshold of 50 dBA (which is the lowest threshold outlined for noise sensitive uses in the guidelines); thus, it is within the outdoor noise level range considered acceptable for residential areas. Vibration Segment 1 (North and South), Segment 2, and Segment 3 South. Operational vibration impacts for Segment 1 (North and South), Segment 2, and Segment 3 South would be to the same as identified for the East Side-Loading Alternative. Changes in vibration levels from single pass-by events would be due to the alignment modifications involved with the Proposed Action. Vibration level estimations for a single pass-by event within Segments 3 North and South all use the same vibration assumptions. The actual soil conditions, however, are slightly different and vibration levels in Segment 3 North are expected to be lower. As shown in Table 4.4-9, the Proposed Action would result in increases in ground-borne vibration. However, the resulting vibration levels would remain below the FTA’s ground-borne vibration impact criterion for Category 2 land uses (72 VdB for frequent events). Therefore, operational vibration impacts within Segment 1 (North and South), Segment 2, and Segment 3 South would not be considered adverse.



Segments 3 North and 3 Central. Table 4.4-12, Changes in Vibration Levels - Segment 3 North and Segment 3 Central, below presents the existing vibration level along with the change of vibration levels for the closest potentially affected structures along Segment 3 North and Segment 3 Central for the West Side-Loading Alternative. This alternative would not exceed the threshold criterion (an increase of 3 VdB for areas that already exceed the FTA threshold levels) for vibration impacts in Segment 3 North or Segment 3 Central. Therefore no adverse operational vibration impacts would occur within Segments 3 North and Central under the West Side-Loading Alternative.

Table 4.4-12 CHANGES IN VIBRATION LEVELS ‒


West Side-Loading Alternative Vibration in VdB re 10-6 ips

Location Land Use Existing Project Change Impact Segment 3 North

West Residential 88.9 90.7 1.8 N Segment 3 Central

East Residential 86.2 86.2 0.0 N West Residential 90.4 90.0 1.5 N

N= No Impact ips = inches per second Source: HELIX 2014b (Appendix C).

Summary of West Side-Loading Alternative Noise and Vibration Impacts Construction of the West Side-Loading Alternative would generate noise and vibration at or above levels established by the FTA as being likely to cause an adverse community reaction. More specifically, residents located west of the railroad tracks to the south of the San Dieguito River would likely experience and adverse reaction during construction of the new bridges over the San Dieguito River, especially during the pile-driving stage of construction. (Unlike the East Side-Loading Alternative, this alternative would not entail realignment of Stevens Creek; accordingly, the West Side-Loading Alternative would not require pile driving near the residences east of the tracks just south of Via de la Valle). Additionally, nighttime construction activities associated construction of double track could result in adverse impacts to residences along the project limits. These adverse impacts associated with bridge construction are not assessed as being substantial under NEPA because of the limited number of residences affected, the temporary duration of the loudest generator of noise impacts (i.e., pile driving), and the relative infrequency of nighttime construction. Although not required to avoid a substantial impact, Section 4.4.4 describes avoidance, minimization, and mitigation measures that could be used to reduce construction noise. Following the completion of construction, the continuing increase in train operation levels, coupled with the new alignment of the railroad tracks, would generate noise level increases at



some residences along the railroad tracks of approximately 1 dBA to 2 dBA. More specifically, south of the San Dieguito River and west of the tracks between 21st Street and the River, up to approximately 30 single-family residences and one multi-family building would experience increases of 1 dBA (between 21st and 22nd Streets) to 2 dBA (between 22nd Street and the San Dieguito River). These increases would constitute a moderate impact per the FTA criteria illustrated on Figure 4.4-3. This approximately 1- to 2-dBA increase would not constitute a substantial impact under NEPA because of the moderate number of residences affected and because a 1- to 2-dBA increase would not be noticeably perceptible to the average person. Moderate noise impacts to residents east of the tracks along Grand Avenue would not be substantial under NEPA for the reasons described for the East Side-Loading Alternative. East Center-Loading Alternative Construction Impacts Noise – Double Track Rail Construction Noise impacts related to double track rail construction would be the same as identified for the East Side-Loading Alternative. The estimated worst-case noise levels for construction equipment in simultaneous operation (running continuously for an 8-hour period) is 76 dBA LEQ for Segment 1, 72 dBA LEQ for Segment 2, and 79 dBA LEQ for Segment 3. These levels do not exceed the daytime impact criterion of 80 dBA LEQ (8-hour), as identified in Table 4.4-3. Therefore, construction noise impacts related to the double track alignment construction during daytime hours are not expected to be adverse in Segments 1, 2, and 3 South. Nighttime noise impacts related to rail alignment construction, however, are expected to be adverse. Noise – Bridge and Platform Construction Daytime and nighttime noise impacts related to bridge and platform construction would be to the same as described for the East Side-Loading Alternative. Daytime construction activities would exceed the impact criterion of 80 dBA LEQ (8-hour). Therefore, the noise impacts related to construction of the bridge and platform would be expected to be adverse. Noise impacts are not expected to be adverse for the nighttime construction installation of prefabricated beams at the bridge and platform. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. Noise – Steven’s Creek Culvert Noise impacts related to construction of the Steven’s Creek culvert would be the same as those described for the East Side-Loading Alternative. Construction noise levels would not exceed the daytime impact criterion of 80 dBA LEQ (8-hour). Therefore, the noise impacts related to alignment construction are not expected to be adverse for the Stevens Creek Culvert.



Vibration – Double Track Rail Construction Vibration impacts related to double track rail construction would be to the same as identified for the East Side-Loading Alternative. The highest levels of construction-related vibration would be associated with a vibratory roller, and would be expected to be approximately 69 VdB at the nearest residence. The impact level used for Category 2 land uses (residences) as listed in Table 4.4-4 is 80 VdB for infrequent events; as most construction actions occur fewer than 30 times per day in close proximity to a specific residential use, the infrequent events impact category for ground-borne vibration levels can be appropriately used here. Therefore, construction vibration impacts related to double track alignment construction would not exceed the impact criterion, and no associated adverse impacts would occur. Vibration – Bridge and Platform Construction Vibration impacts related to bridge and platform construction would be to the same as identified for the East Side-Loading Alternative. The greatest construction vibration effects associated with bridge and platform construction would be caused by a vibratory pile driver, which has a maximum vibration level of 105 VdB (maximum) at 25 feet. At a distance of 190 feet, the maximum vibration level at the nearest residence would be 79 VdB. Due to the nature of a vibratory pile driver, this activity is assumed to have many events in a given period, therefore the criteria used is for frequent events. Given this range, it is reasonable to expect that vibration from bridge and platform construction would exceed the impact criterion (72 VdB for frequent events), depending on the frequency and power of the driver. As noted previously, exceeding 72 VdB (for frequent events) at residential areas is likely to cause an adverse community reaction. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. Approximately 13 single-family residences and a multi-family building would experience these potentially adverse construction noise and vibration levels. Vibration - Stevens Creek Culvert Supports for the Stevens Creek culvert would be installed using a vibratory pile driver. The closest distance to a residence is 290 feet. At this distance, the vibratory pile driver would result in a maximum level of 73 VdB, which would exceed the threshold of 72 VdB for frequent events. An adverse construction impact would occur. Operational Impacts Noise – Rail Noise Segment 1, Segment 2, and Segment 3 South. Operational noise impacts for Segments 1 (North and South), Segment 2, and Segment 3 South would be the same as identified for the East Side-Loading Alternative. No operational noise impacts would occur within Segment 1 North, Segment 1 South, or Segment 2. Operational noise impacts within Segment 3 South would be considered moderate per FTA criteria under future conditions, however. As stated in the discussion for the East Side-Loading Alternative, estimated noise levels at the residences located



along the eastern side of the tracks would increase by 1 dBA in all future scenarios (years 2020, 2025, and 2030). Future baseline (No Action) noise levels would increase from 75 dBA to 76 dBA at a distance of 75 feet, and from 73 dBA to 74 dBA at 100 feet. The increase is primarily due to the eastern track shifting 17 feet further to the east (closer to the residences). According to FTA criteria (refer to Figure 4.4-3), because the baseline is above 70 decibels, the increase of 1 dBA would be considered a “Moderate Impact” (refer to Table 4.4-7). Segments 3 North and Central. Table 4.4-13, Modifications of Rail Track Centerline from Existing Alignment - Segments 3 North and Central, below shows the offset distances for the eastern and western railroad tracks from the existing track for Segment 3 North and Central with implementation of the East Center-Loading Alternative.

Table 4.4-13 MODIFICATIONS OF RAIL TRACK CENTERLINE FROM

EXISTING ALIGNMENT - SEGMENTS 3 NORTH AND CENTRAL

East Center-Loading Alternative

West Track East Track

Segment 3 North 12 feet East 57 feet East Segment 3 Central 6 feet East 34 feet East Source: HELIX 2014b (Appendix C).

Noise levels from rail operations on the western side of the tracks would decrease by 1 dBA to 2 dBA along Segment 3 North. No operational noise impacts would occur. The nearest residences along Segment 3 Central are located east of the tracks at distances between 150 feet and 20 feet. Along the eastern side of the tracks within Segment 3 Central, estimated noise levels under the future years (2020, 2025, and 2030) would range from 69 dBA at 200 feet to 71 dBA at 150 feet. Under this alternative, noise levels on the eastern side of the rail would increase by approximately 1 dBA. This increase would exceed the FTA impact criteria. As a result, a moderate operational noise impact to residents east of the tracks would occur within Segment 3 Central under the East Center-Loading Alternative. Rail noise levels would decrease by approximately 1 dBA on the western side of Segment 3 Central in all future scenarios at distances between 75 feet and 200 feet. No adverse operational noise impacts to these residences would occur. Noise – Platform Passenger Noise Potential noise impacts related to the proposed rail platforms for this alternative would be the same as identified for the East Side-Loading Alternative. When considered together, the three potential noise sources associated with the platform noted above (including trains [braking, idling locomotive engines, and accelerating locomotive engines], human speech/communications



on the platform, and potential PA systems) were modeled to have a noise level at the nearest residence of 47 dBA LEQ. This noise level would not be considered an impact pursuant to FTA guidance, as it would not be above the threshold of 50 dBA (which is the lowest threshold outlined for noise sensitive uses in the guidelines); thus, it is within the outdoor noise level range considered acceptable for residential areas. Vibration Segment 1 (North and South), Segment 2, and Segment 3 South. Operational vibration impacts for Segment 1 (North and South), Segment 2, and Segment 3 South would be the same as identified for the East Side-Loading Alternative. Changes in vibration levels from single pass-by events would be due to the alignment modifications involved with the Proposed Action. Vibration level estimations for a single pass-by event within Segments 3 North and South all use the same vibration assumptions. The actual soil conditions, however, are slightly different and vibration levels in Segment 3 North are expected to be lower. As shown in Table 4.4-9, the Proposed Action would result in increases in ground-borne vibration. However, the resulting vibration levels would remain below the FTA’s ground-borne vibration impact criterion for Category 2 land uses (72 VdB for frequent events). Therefore, operational vibration impacts within Segment 1 (North and South), Segment 2, and Segment 3 South would not be considered adverse. Segments 3 North and Segment 3 Central. Table 4.4-14, Changes in Vibration Levels - Segments 3 North and Central, below presents the existing vibration level along with the change of vibration levels for the closest potentially affected structures along Segment 3 North and Segment 3 Central for the East Center-Loading Alternative. This alternative would not exceed the threshold criterion for vibration impacts in Segments 3 Central or North. Therefore, no adverse operational vibration impacts would occur within Segments 3 North and Central under the East Center-Loading Alternative.

Table 4.4-14 CHANGES IN VIBRATION LEVELS


East Center-Loading Alternative Vibration in VdB re 10-6 ips

Location Land Use Existing Project Change Impact North

West Residential 86.2 87.6 1.4 N Central

East Residential 86.2 87.6 1.4 N West Residential 88.9 88.2 -0.6 N

Note: Commercial uses in this section would increase approximately 3.4 to 3.7 VdB; however, these uses are not vibration sensitive. ips = inches per second Source: HELIX 2014b (Appendix C).



Summary of East Center-Loading Alternative Noise and Vibration Impacts The noise and vibration impacts associated with this alternative would be similar to those described for the East Side-Loading Alternative and would not be substantial under NEPA for the reasons described for that alternative. No Action Alternative Construction Impacts Noise and Vibration The No Action Alternative would not result in construction noise or vibration impacts because no construction activities would occur. Operational Impacts Noise – Rail Noise Segment 1 (North and South), Segment 2, and Segment 3 South. Changes in noise levels when comparing existing noise levels to future (2020, 2025, and 2030) noise levels with the No Action Alternative are primarily due to the anticipated increase in train operations associated with future demand along the rail line. Rail capacity would be constrained by the limits of the existing rail configuration in 2020, and rail trips would not increase beyond 2020 levels. Within Segment 1 (North and South), Segment 2, and Segment 3 South, the increases in noise levels follow a similar pattern. From existing conditions to 2020, noise levels would increase by 2 dBA to 3 dBA. After 2020, noise levels would no longer increase, and would remain at a constant level. This would result in moderate impacts at receptor locations in some areas (Segment 2 South [eastern side of tracks], Segment 3 South [eastern and western sides of tracks]). Segment 3 North and Central. Within Segment 3 Central and North, noise levels associated with the No Action Alternative would increase by up to 1 dBA. This increase in noise levels would not exceed FTA criteria. As a result, no adverse operational noise impacts would occur within Segment 3 North and Central under the No Action Alternative. Noise – Rail Platform Noise The No Action Alternative would not construct a special events rail platform adjacent to the Fairgrounds; therefore, no operational noise impacts would occur. Vibration With the No Action Alternative, vibration levels would be similar to what would be expected with the Action Alternatives. The only exception would be Segment 3 Central, where the raised



railroad bed that would be constructed under the East Side-Loading Alternative would dampen vibration impacts. Vibration impacts under the No Action Alternative would not exceed federal criteria. No adverse operational vibration impacts would occur under the No Action Alternative. Summary of No Action Alternative Noise and Vibration Impacts There would be no construction, and therefore no construction-related noise and vibration impacts, under the No Action Alternative. The moderate increase in train operation-related noise would not constitute a substantial impact under NEPA because these increases represent a future baseline against which the Proposed Action alternatives should be considered and would not be the result of any action (funding or project approval) taken by the FRA. Impact Summary Table 4.4-15, Noise and Vibration Impact Summary, below summarizes the noise and vibration impacts, related to both construction and operation, associated with the proposed Action Alternatives, along with the No Action Alternative.

Table 4.4-15 NOISE AND VIBRATION IMPACT SUMMARY

Rail Facility or Segment

East Side-Loading Alternative

West Side-Loading Alternative

East Center-Loading

Alternative

No Action Alternative

Construction Impacts

Daytime Nighttime Daytime Nighttime Daytime Nighttime Daytime Nighttime

Double Track Rail No

impacts N

No impacts

N No

impacts N

No impacts

N

Bridge/Platform N/V No

impacts N/V

No impact

N/V No

impacts No

impacts No

impacts Steven’s Creek

Culvert V -- -- -- V --

No impacts

No impacts

Operational Impacts

Segment 1 North -- -- -- --

Segment 1 South -- -- -- N

Segment 2 -- -- -- N

Segment 3 North -- N (west of rail) -- --

Segment 3 Central N (east of rail) N (west of rail) N (east of rail) --

Segment 3 South N (east of rail) N (east of rail) N (east of rail) N N = Noise impact likely to cause an adverse community reaction (during construction) or assessed as “Moderate” per FTA criteria

(resulting from train operations) V = Vibration level assessed as likely to cause an adverse community reaction (during construction)



4.4.4 Avoidance, Minimization, and Mitigation Measures FRA does not have standardized criteria for construction noise impacts; however, mitigation is recommended if construction noise exceeds the noise levels listed in Table 4.4-3. Mitigation guidelines for rail operation impacts for the three categories identified by FRA are as follows: No Impact: No mitigation required. Moderate Impact: Mitigation is not required, but may be considered depending on

considerations including but not limited to: the number of noise-sensitive receptors affected, the increase over existing noise levels, the noise sensitivity of affected land uses, the effectiveness of proposed mitigation, and community views.

Severe Impact: Consideration of feasible and effective mitigation is required if impacts

cannot be avoided. East Side-Loading Alternative Construction Measures Under all Action Alternatives, adverse construction noise and vibration impacts would occur due to bridge and platform construction. Adverse vibration impacts due to construction of the Stevens Creek culvert would also occur under this alternative. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. Noise During construction, temporary noise impacts would occur in active construction zones and could affect noise-sensitive uses along the project limits. Construction noise sources would be localized and would migrate along the alignment as construction proceeds. Potential general noise reduction strategies for construction noise impacts include the following measures: Construct noise barriers, such as temporary walls or berms, between noisy activities and

residences.

Combine noisy operations so they occur in the same time period. The total noise level produced would not be substantially greater than if the operations were performed separately.

Avoid nighttime construction when feasible. If nighttime work is necessary, either use smart back-up alarms, which automatically adjust the alarm level based on the background noise level, or switch off back-up alarms and replace with spotters.

Implement noise-deadening measures for truck loading and operations.



Monitor and maintain equipment to meet noise limits.

Minimize the use of generators to power equipment. Vibration A vibratory pile driver may create vibration impacts at nearby residential locations within 325 feet of residences under any action alternative. Vibration monitoring could be provided at the nearby residential locations when a pile driver is used within this distance (325 feet) of a residence. If the vibration levels exceed a level of 72 VdB, the power level of the pile driver could be reduced, or vibration shielding provided via a trench or alternative method, to reduce vibration impacts. Operational Measures Noise Segments 1 North and South. No adverse operational noise impacts associated would occur within Segments 1 North and South under this alternative; therefore, no noise reduction measures are necessary. Segment 2. No adverse operational noise impacts associated would occur within Segment 2 under this alternative; therefore, no noise reduction measures are necessary. Segments 3 North. No adverse operational noise impacts associated would occur within Segment 3 North under this alternative; therefore, no noise reduction measures are necessary. Segment 3 Central (east of rail) and Segment 3 South (east of rail). The East Side-Loading Alternative would result in moderate operational noise impacts associated with rail operations to sensitive receivers (i.e., residences) on the east side of the railroad, including approximately two single-family homes north of Camino Del Mar and east of Jimmy Durante Boulevard and up to approximately 12 single-family residences and 1 multi-family building south of Camino Del Mar along Grand Avenue, and to (refer to Figures 4.4-5a and 4.4-5b). The moderate impacts that would occur under this alternative would affect residences that are already exposed to noise levels that exceed typically acceptable levels for these uses. As previously discussed, this moderate impact would not constitute a substantial impact under NEPA because of the relatively low number of residences affected and because a 1-dBA increase, which is barely perceptible to the average person, is at the lowest end of the range for a “Moderate Impact.” No noise reduction measures are required. Vibration No adverse operational vibration impacts would occur within any segments under this alternative; therefore, no noise reduction measures are necessary.



West Side-Loading Alternative Construction Measures Under all Action Alternatives, adverse construction noise and vibration impacts would occur due to bridge and platform construction. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. Noise Construction noise measures for the West Side-Loading Alternative would be the same as those identified above for East Side-Loading Alternative. Vibration Construction vibration measures for the West Side-Loading Alternative would be the same as those identified above for the East Side-Loading Alternative. Operational Measures Segments 1 North and South. No adverse operational noise impacts associated would occur within Segments 1 North and South under this alternative; therefore, no noise reduction measures are necessary. Segment 2. No adverse operational noise impacts associated would occur within Segment 2 under this alternative; therefore, no noise reduction measures are necessary. Segments 3 North (west of rail) and Central (west of rail). The West Side-Loading Alternative would result in moderate operational noise impacts associated with rail operations to sensitive receivers (i.e., residences) west of the rail alignment within Segment 3 North, along with the very northern portion of Segment 3 Central, including up to approximately 30 single-family residences and one multi-family building south of the San Dieguito River and west of the tracks between 21st Street and the San Dieguito River (refer to Figures 4.4-5a and 4.4-5b). The moderate impacts that would occur under this alternative would affect residences that are already exposed to noise levels that exceed typically acceptable levels for these uses. As previously discussed, this moderate impact would not constitute a substantial impact under NEPA because of the moderate number of residences affected and because a 1- to 2-dBA increase would not be noticeably perceptible to the average person. No noise reduction measures are required. Segment 3 South (east of rail). The West Side-Loading Alternative would result in moderate operational noise impacts associated with rail operations to sensitive receivers (i.e., residences) on the east side of the tracks, including up to approximately 12 single-family residences and one multi-family building south of Camino Del Mar along Grand Avenue, and to (refer to Figures 4.4-5a and 4.4-5b). The moderate impacts that would occur under this alternative would affect residences that are already exposed to noise levels that exceed typically acceptable levels for these uses. As previously discussed, this moderate impact would not constitute a substantial



impact under NEPA because of the relatively low number of residences affected and because a 1-dBA increase, which is barely perceptible to the average person, is at the lowest end of the range for a “Moderate Impact.” No noise reduction measures are required. East Center-Loading Alternative Construction Measures As with the other two Action Alternatives, adverse construction noise and vibration impacts would occur due to bridge and platform construction under the East center-Loading Alternative. Adverse vibration impacts due to construction of the Stevens Creek culvert would also occur under this alternative. Refer to Figures 4.4-5a and 4.4-5b for locations that would be expected to have potentially adverse construction noise and vibration impacts. Noise Construction noise measures for the East Center-Loading Alternative would be the same as those identified for the East Side-Loading Alternative. Vibration Construction vibration measures for the East Center-Loading Alternative would be the same as those identified for the East Side-Loading Alternative. Operational Measures Segments 1 North and South. No adverse operational noise impacts associated would occur within Segments 1 North and South under this alternative; therefore, no noise reduction measures are necessary. Segment 2. No adverse operational noise impacts associated would occur within Segment 2 under this alternative; therefore, no noise reduction measures are necessary. Segment 3 North. No adverse operational noise impacts associated would occur within Segment 3 North under this alternative; therefore, no noise reduction measures are necessary. Segment 3 Central (east of rail) and Segment 3 South (east of rail). The East Center-Loading Alternative would result in moderate operational noise impacts associated with rail operations to sensitive receivers (i.e., residences) on the east side of the tracks, including approximately 2 single-family homes north of Camino Del Mar and east of Jimmy Durante Boulevard and up to approximately 12 single-family residences and 1 multi-family building south of Camino Del Mar along Grand Avenue, and to (refer to Figures 4.4-5a and 4.4-5b). The moderate impacts that would occur under this alternative would affect residences that are already exposed to noise levels that exceed typically acceptable levels for these uses. As previously discussed, this moderate impact would not constitute a substantial impact under NEPA because of the relatively low number of residences affected and because a 1-dBA increase, which is barely perceptible to



the average person, is at the lowest end of the range for a “Moderate Impact.” No noise reduction measures are required. No Action Alternative Although increases in operational noise impacts would occur under the No Action Alternative, no avoidance, minimization, or mitigation measures would be required for the No Action Alternative because no action is proposed under this alternative.


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4.4 NOISE AND VIBRATION - gsws.com to differentiate the sensitivity to ground-borne vibration: Category 1 includes buildings where vibration would interfere with interior operations