3.0 – Environmental Resources, Impacts and Mitigation Pacific Surfliner Sorrento to Miramar Phase 2 Double-Track Project 3.10-1 July 2016 Final EA 3.10 Noise and Vibration The information provided in this section is summarized from the Noise Analysis Report for the Pacific Surfliner Sorrento to Miramar Phase 2 Double-Track Project prepared by Entech Consulting Group (Entech, 2013b). The Noise Analysis Report is provided as Appendix K of this EA. 3.10.1 Regulatory Setting FTA provides guidelines for the assessment of noise and vibration impacts. There are also state and local guidelines related to potential noise impacts associated with rail projects at sensitive receiving properties. Federal Federal Transit Administration Noise Criteria The FRA relies upon FTA guidelines to assess noise impacts from passenger rail and freight trains. The FTA has identified various noise impact criteria for mass transit projects involving rail or bus facilities. These guidelines vary as a function of receiving land use, ambient noise level and project noise exposure. Federal Transit Administration Operational Vibration Criteria FTA operational vibration criteria are based in part on the frequency of events and related groundborne vibration that can cause human annoyance or interference with the use of vibration-sensitive equipment. Vibration-sensitive receptors include single- and multi-family residences, hotels, schools, and parks. 3.10.2 Affected Environment The primary noise sources adjacent to the project site include aircraft operations from MCAS Miramar, vehicular traffic along I-805, Sorrento Valley Road and Miramar Road, and passenger and freight train operations along the San Diego Northern Railroad. Noise is also generated by existing commercial and light industrial uses adjacent to the proposed project site, as well as vehicular traffic noise along the adjacent industrial park roads. The noise at the industrial parks is primarily associated with heavy truck traffic and loading dock activities, which generate intermittent noise in the vicinity of the industrial parks. Under Existing Conditions (Year 2013), there are approximately 50 passenger and freight trains that travel through the corridor. Passenger trains generally consist of one engine and three to five cars. Amtrak trains generally consist of one engine and five to ten cars. The majority of the Coaster and Amtrak trains operate between the hours of 7 a.m. to 10 p.m. Freight trains are not on a set time schedule. It was assumed that the freight trains operate between the hours of 12 a.m. to 5 a.m. under existing conditions (year 2013) in addition to 7 a.m. to 10 p.m.. For Future No Project conditions (year 2020), it is estimated the approximately 67 trains will travel through the corridor.
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3.10 Noise and Vibration - gsws.com · The FTA Transit Noise and Vibration Impact Assessment (FTA, 2006) guidance manual has grouped noise sensitive land uses into three categories:
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3.0 – Environmental Resources, Impacts and Mitigation
Pacific Surfliner Sorrento to Miramar Phase 2 Double-Track Project 3.10-1 July 2016 Final EA
3.10 Noise and Vibration The information provided in this section is summarized from the Noise Analysis Report for the Pacific Surfliner
Sorrento to Miramar Phase 2 Double-Track Project prepared by Entech Consulting Group (Entech, 2013b).
The Noise Analysis Report is provided as Appendix K of this EA.
3.10.1 Regulatory Setting FTA provides guidelines for the assessment of noise and vibration impacts. There are also state and local
guidelines related to potential noise impacts associated with rail projects at sensitive receiving properties.
Federal
Federal Transit Administration Noise Criteria
The FRA relies upon FTA guidelines to assess noise impacts from passenger rail and freight trains. The FTA has
identified various noise impact criteria for mass transit projects involving rail or bus facilities. These guidelines
vary as a function of receiving land use, ambient noise level and project noise exposure.
Federal Transit Administration Operational Vibration Criteria
FTA operational vibration criteria are based in part on the frequency of events and related groundborne
vibration that can cause human annoyance or interference with the use of vibration-sensitive equipment.
Vibration-sensitive receptors include single- and multi-family residences, hotels, schools, and parks.
3.10.2 Affected Environment The primary noise sources adjacent to the project site include aircraft operations from MCAS Miramar,
vehicular traffic along I-805, Sorrento Valley Road and Miramar Road, and passenger and freight train
operations along the San Diego Northern Railroad. Noise is also generated by existing commercial and
light industrial uses adjacent to the proposed project site, as well as vehicular traffic noise along the
adjacent industrial park roads.
The noise at the industrial parks is primarily associated with heavy truck traffic and loading dock activities,
which generate intermittent noise in the vicinity of the industrial parks. Under Existing Conditions (Year
2013), there are approximately 50 passenger and freight trains that travel through the corridor. Passenger
trains generally consist of one engine and three to five cars. Amtrak trains generally consist of one engine
and five to ten cars. The majority of the Coaster and Amtrak trains operate between the hours of 7 a.m. to
10 p.m. Freight trains are not on a set time schedule. It was assumed that the freight trains operate
between the hours of 12 a.m. to 5 a.m. under existing conditions (year 2013) in addition to 7 a.m. to 10
p.m.. For Future No Project conditions (year 2020), it is estimated the approximately 67 trains will travel
through the corridor.
3.0 – Environmental Resources, Impacts and Mitigation
Pacific Surfliner Sorrento to Miramar Phase 2 Double-Track Project 3.10-2 July 2016 Final EA
3.10.2.1 Surrounding Land Use Sensitive Receptors A field reconnaissance of the proposed project area was performed to identify FTA noise criteria land uses.
The Project Alternatives are located within a canyon, just south of Nancy Ridge Drive. Located on the
northern and southern ridges overlooking the canyon are office, commercial and light industrial land uses,
which have a direct line of sight of the Project Alternatives area. However, commercial and light industrial
land uses are not included in the FTA noise land use categories. Approximately 1,500 ft north of the
Alternative 2 alignment limits is the Sorrento Canyon Golf Center, which is considered an outdoor
recreational use area. However, 1,200 ft is FTA’s screening distance for noise impacts to sensitive receptors.
As such, there are no known sensitive land use receptors within 1,200 ft of the railroad.
3.10.2.2 Sensitive Habitats Near Transit Noise Noise levels in exceedance of 60 dBA can potentially interrupt ongoing activities within the habitat of
sensitive species. Disruption caused by noise near these sensitive habitats can greatly alter the behavior of
the sensitive species mating habits, migration patterns and other behavioral characteristics.
3.10.2.3 Existing Noise Levels Sound is a physical phenomenon consisting of minute vibrations that travel through a medium, such as air,
and are sensed by the human ear. Sound is generally characterized by several variables, including
frequency and intensity. Frequency describes the sound’s pitch and is measured in cycles per second, or
hertz (Hz), whereas intensity describes the sound’s loudness and is measured in decibels (dB). Decibels are
measured using a logarithmic scale. The A-weighted sound pressure level (abbreviated as dBA) is the
sound level with the “A-weighting” frequency correction. Because community noise fluctuates over time, a
single measure called the Equivalent Sound Level (Leq) is used to describe the time-varying character of
community noise. The Leq is the energy-averaged A-weighted sound level during a measured time interval.
It is equal to the level of continuous steady sound containing the same total acoustical energy over the
averaging time period as the actual time-varying sound. Additionally, it is often desirable to know the
acoustic range of the noise source being measured. This is accomplished through the Lmax and Lmin
indicators, which represent the root-mean-square maximum and minimum noise levels obtained during the
measurement interval. The Lmin value obtained for a particular monitoring location is often called the
“acoustic floor” for that location.
Table 3.10-1 shows the typical measured maximum noise levels for the passenger and freight trains, the
typical SEL value for various passbys along the site and the average CNEL value found along the railroad
alignment.
Existing noise levels were determined at two separate locations along the proposed alignments using the
FTA recommended distance of 50 ft from the railroad tracks. It was assumed that the highest noise levels
would occur at this distance. One long-term (24-hour) measurement and seven short-term measurements
were taken at monitoring location #1, shown in Figure 3.10-1. In addition, six short-term measurements were
taken at monitoring location #2, shown in Figure 3.10-2. The two monitoring locations represent the
variations in the grade of the existing track, which may influence the speed of passenger and freight trains.
The current maximum speeds for this segment are 25 mph for passenger trains and 20 mph for freight trains.
3.0 – Environmental Resources, Impacts and Mitigation
Pacific Surfliner Sorrento to Miramar Phase 2 Double-Track Project 3.10-3 July 2016 Final EA
Table 3.10-1 Existing Passenger and Freight Noise Levels
From Miramar Road to Carroll Creek
Train Type Passby Speed Approximate
Maximum Sound Level (dBA)
Approximate Sound Exposure
Level (dBA) CNEL (dBA)
Coaster 30 89 94 -- Amtrak 30 97 95 -- Freight 20 107 112 -- All Passenger and Freight Trains1 73 Note: CNEL based on Coaster: 24 trains; Amtrak: 22 trains; Freight: 8 trains. Source: Entech, 2013.
Long-Term Measurements
One long-term measurement was taken at location #1, which started on Tuesday, March 30, 2010 at 10:00
a.m. and ended on Wednesday, March 31, 2010 at 10:00 a.m. The peak hour noise level was found to be
79 dBA Leq between the hours of 7:00 a.m. and 8:00 a.m. The average hourly Leq was found to range from
45 to 79 dBA Leq. The cumulative average CNEL was determined to be approximately 73 dBA at a
reference distance of 50 ft to the track. A summary of the long-term results is presented in Figure 8 of the
Noise Analysis Report.
Short-Term Measurements
Short-term measurements for location #1 were taken for three Coaster trains and four Amtrak trains. At
location #2, short-term measurements were taken for three Coaster trains and three Amtrak trains. Coaster
sound levels ranged from 73 to 78 dBA Leq and Amtrak sound levels ranged from 73 to 85 dBA Leq. A
summary of short-term results can be found in Table 4-1 of the Noise Analysis Report.
The maximum sound level and sound exposure level (SEL) for several train events were measured to identify
any instantaneous sound levels generated from existing train operations. At a reference distance of 50 ft to
the middle of the track, the measured maximum noise level varied from 83 to 90 dBA Leq for the Coaster
trains and 84 to 97 dBA for the Amtrak trains. The maximum noise level for freight trains was approximately
98 to 107 dBA Leq. The sound level produced by each train passby is immediate and lasts no longer than 30
seconds. Between the hours of 6:00 a.m. and 10:00 p.m., which are the approximate hours of Coaster and
Amtrak operation, the long-term and short-term measurements average hourly Leq sound levels range from
53 to 79 dBA Leq. Nighttime sound levels were found to range from 45 to 49 dBA Leq when there is an
absence in train passbys. However, when freight trains passby, sound levels range from 51 to 61 dBA Leq
between the hours of 12:00 a.m. to 2:00 a.m. The existing 24-hour average of 71 dBA Leq and the
cumulative CNEL of 73 dBA is representative of all train types and passby events that have an influence on
contributing to the existing noise environment at a reference distance of 50 ft.