2.
Response
to
Comments
2.9
Individual
Responses
to
Comments
from
Organizations
concluded
that
potential
school
sites
designated
in
the
DSP,
DSP-V,
CPP,
and
CPP-V
scenarios
would
be
exposed
to
future
with-project
noise
of
normal
to
conditionally
acceptable
levels
(Draft
EIR,
pages.
4.J-19
and
4.J-20).
Noise
Monitoring
location
6
on
Figure
4.J-2
represents
the
location
of
the
proposed
school
under
the
DSP
and
DSP-V
scenarios.
The
noise
level
of
67
CNEL
at
this
location
would
be
in
the
conditionally
acceptable
noise
exposure
category
for
school
land
uses
based
on
the
acceptable
noise
exposures
for
land
use
compatibility
chart
published
by
the
State
of
California
and
presented
in
Figure
4.J-3
of
the
Draft
EIR.
As
stated
on
Draft
EIR
page
prior
to
acquiring
land
for
the
school,
specific
siting
studies
for
the
proposed
school
facility
within
the
Baylands
will
need
to
be
undertaken
to
evaluate
site
remediation
and
noise
conditions.
Thus,
potential
future
school
sites
were
not
overlooked
by
the
EIR
noise
analysis.
Draft
EIR
page
4.J-16
referenced
by
Comment
addresses
the
methodology
used
to
assess
impacts
related
to
temporary
construction
noise.
The
actual
analysis
of
construction
noise
begins
on
Draft
EIR
page
4.J-31
and
identifies
a
significant
impact
with
regard
to
pile
driving
noise
as
well
as
mitigation
of
pile
driving
noise.
Vibration
impacts
related
to
pile
driving
are
assessed
beginning
on
Draft
EIR
page
4.J-22.
The
duration
of
pile
driving
activities
depends
on
a
number
of
factors
including
building
design
and
depth
to
bedrock.
It
can
reasonably
be
expected
that
a
substantial
multi-story
structure
may
require
multiple
weeks
of
pile
driving.
Building
details
and
design
heights
are
not
known
for
purposes
of
this
programmatic
level
of
assessment
of
Project
Site
development,
and
therefore,
noise
impacts
associated
with
the
construction
of
specific
buildings
will
be
analyzed
during
the
environmental
review
of
site-
specific
development
proposals.
The
unique
environment
of
the
City
of
Brisbane
is
not
that
it
amplifies
sound,
but
rather
that
it
is
an
efficient
transmitter
of
sound.
The
slope
of
the
valley
means
that
homes,
like
seats
in
an
amphitheater,
have
a
“good
view”
of
noise
sources.
This
means
that
noise
will
propagate
better
than
in
a
typical
flat
community
because
buildings
are
less
likely
to
intercept
the
line-of-
sight
to
a
noise
source.
The
effect
of
construction
of
buildings
within
the
Baylands
site
area
would
be
to
reduce
noise
contributions
from
distant
sources,
such
as
U.S.
101
and
Caltrain,
by
providing
a
line-of-sight
interruption
which
would
more
than
outweigh
any
contributions
of
building
reflection
5
.
5
The
decibel
scale
(dB)
expresses
the
difference
in
loudness
between
two
sounds.
A
perfect
reflector
is
limited
to
doubling
of
sound
energy,
which
translates
to
a
sound
level
increase
of
3
dB
because
the
decibel
scale
is
a
logarithmic
scale.
Because
of
absorption,
reflected
sound
level
increases
are
always
less
than
3
dB.
Comparatively,
Caltrans
estimates
that
shielding
by
intervening
houses
or
buildings
in
an
urban
environment
can
provide
5
to
10
dBA
of
reduction.
(Caltrans,
2013).
Brisbane
Baylands
Final
EIR
2.9.3-97
May
2015