Santa Clara Valley Transportation Authority
5. NEPA Environmental Assessment
FTA has developed guidelines for assessing construction noise and vibration impacts. These
guidelines, along with applicable local ordinances, are used to assess construction noise
effects. Operation of the Project would result in an adverse effect if noise levels from the bus
rapid transit vehicles would exceed the noise impact criteria found in FTA’s Transit Noise
and Vibration Assessment guidance manual.
5.11.1.2
No Build Alternative (No adverse effect)
Under the No Build Alternative, existing roadway and transit services in the Project corridor
would remain unchanged, except that VTA would replace the existing Rapid 522 buses with
low-floor BRT-style buses in 2015. At the same time, VTA would decrease headways for
Rapid 522 and increase headways for Local 22. There would be no construction activities
associated with the No Build Alternative. As a result, No adverse effects related to noise or
vibration would occur under the No Build Alternative.
5.11.1.3
Build Alternatives (No adverse effect after mitigation)
Construction
As described in Section 4.11, Noise and Vibration, construction of any of the Build
Alternatives would periodically result in increases in ambient noise levels at residences and
other noise-sensitive land uses. While construction of the entire Project is scheduled to take
up to 2 years to complete, construction at a given location would be intermittent and shortterm. Construction would primarily occur during daytime hours. However, construction may
occur before 8:00 a.m. or after 5:30 p.m. on weekdays. Actual noise levels at a given receiver
location would vary considerably based on the location of equipment and the phase of the
Project. Construction noise levels could be up to 88 dBA Leq (8-hour) (see Section 4.11 for a
full discussion of noise measurements) at a distance of 50 feet from the noise source during
the loudest phase of Project construction (paving), resulting in a temporary increase in
ambient sound levels of more than 6 dBA in some locations.
This effect would be adverse. However, this adverse effect would be mitigated by
implementation of MM NOI-A: Employ noise-reducing practices during construction
and MM NOI-B: Prior to construction, initiate a complaint/response tracking program,
ensuring construction noise levels do not exceed FTA criteria.
As described in Section 4.11, Noise and Vibration, groundborne vibration from construction
of the Project may periodically result in perceptible vibration levels within nearby residences,
lodging facilities, and schools located within 110 feet of construction areas.
This effect would be an adverse effect. However, this adverse effect would be mitigated by
implementation of MM NOI-C: Employ vibration-reducing practices during
construction which would reduce the effect by ensuring vibration from construction is
minimized.
El Camino Real Bus Rapid Transit Project
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Environmental Assessment
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Santa Clara Valley Transportation Authority
5. NEPA Environmental Assessment
With incorporation of mitigation measures MM NOI-A, MM NOI-B, and MM NOI-C, no
adverse effects related to noise or vibration would occur under any of the Build Alternatives.
Operation
In addition, noise levels would increase by 1 dB or less due to operation of mixed-flow and
dedicated lane scenarios. On an hourly average basis, this increase would not result in a
discernible change from existing ambient noise conditions. Under FTA criteria, noise levels
at all receiver locations would be below Moderate Impact thresholds. This effect would not
be adverse.
5.11.2
5.11.2.1
Measures to Minimize Harm
No Build Alternative
No adverse noise or vibration effects would occur under the No Build Alternative; therefore,
no mitigation measures are required.
5.11.2.2
Build Alternatives
In order to ensure that adverse noise and vibration effects related to construction are
minimized, the following mitigation measures are recommended (complete text of mitigation
measures are provided in Section 4.11, Noise and Vibration):
MM NOI-A: Employ noise-reducing practices during construction
MM NOI-B: Prior to construction, initiate a complaint/response tracking program
MM NOI-C: Employ vibration-reducing practices during construction
5.11.3
Cumulative Impacts
Refer to Section 4.11, Noise and Vibration, for a comprehensive discussion of cumulative
impacts pursuant to NEPA. No cumulatively adverse noise and vibration effects are
anticipated to occur.
5.12
Transportation and Traffic
For a comprehensive discussion of the Project’s affected environment and cumulative
impacts as it relates to transportation and traffic, refer to Section 4.12, Transportation and
Traffic and the Traffic Operations Analysis Report in Appendix H.
5.12.1
Methods
This section examines whether the Project would have an adverse effect on transportation
and traffic. NEPA does not have specific requirements related to impacts on this resource.
NEPA analyzes impacts in terms of context and intensity. CEQA Guidelines are used to
El Camino Real Bus Rapid Transit Project
Draft Environmental Impact Report/
Environmental Assessment
5-44
October 2014
ICF 00710.12