2.
Response
to
Comments
2.9
Individual
Responses
to
Comments
from
Organizations
predictions
in
the
Draft
EIR
do
not
take
into
account
any
acoustical
shielding
by
intervening
buildings,
they
therefore
are
appropriate
for
the
analysis
at
elevated
receivers,
given
Brisbane’s
terrain.
Similar
noise
predictions
would
tend
to
be
more
conservative
for
more
low-lying
areas
of
the
community,
which
would
experience
shielding
by
intervening
buildings.
Soil
and
subsurface
conditions
are
known
to
have
an
influence
on
the
levels
of
ground-borne
vibration.
Experience
with
ground-borne
vibration
is
that
vibration
propagation
is
more
efficient
in
stiff
clay
soils,
which
are
not
present
within
the
existing
landfill.
The
reference
vibration
levels
inventoried
by
U.S.
DOT
were
developed
to
include
a
reasonable
estimate
for
a
wide
range
of
soil
conditions
(FTA,
2006).
Noise
levels
propagate
through
air
and
would
be
unaffected
by
soil
conditions,
although
hard
surfaces
such
as
pavement
can
result
in
an
added
reflective
contribution
of
one
to
two
decibels.
The
discussion
on
page
4.J-6
accurately
states
that
the
Baylands
Project
site
does
not
“immediately
border”
residential
areas,
but
that
the
nearest
existing
residential
uses
are
within
0.25
miles
of
the
Baylands
Project
Site.
The
only
residential
uses
that
would
be
adjacent
to
Baylands
construction
activities
would
be
the
residential
uses
proposed
in
the
DSP
and
DSP-V
scenarios.
The
Roundhouse
is
considered
with
respect
to
structural
damage
from
construction-related
vibration
in
Impact
4.J-2
of
the
Draft
EIR.
Because
it
is
not
currently
occupied,
the
Roundhouse
is
not
a
sensitive
receptor
with
respect
to
noise.
[See
page
for
the
original
comment]
Ambient
noise
was
monitored
at
eight
locations
all
of
which
are
within
the
City
of
Brisbane,
six
of
which
were
on
the
flatlands
and
two
of
which
were
off-site
at
elevations
of
75
and
225
feet
above
mean
sea
level,
respectively.
Noise
monitoring
locations
at
off-site
receptors
were
selected
based
on
proximity
to
the
Baylands
Project
site
in
order
to
establish
the
existing
noise
levels
at
the
closest
sensitive
receptors
that
would
be
most
impacted
by
construction
activities
or
operations
on
the
Baylands
site.
More
distant
receptors
would
be
affected
to
a
lesser
degree
due
to
the
attenuation
of
sound
with
distance.
The
off-site
noise
monitoring
locations
shown
in
Draft
EIR
Figure
4.J-2
represent
those
locations
that
are
nearest
to
the
Baylands
site
area
and,
therefore,
would
be
the
most
highly
impacted.
Other
more
distant
receptors
of
the
Northeast
Ridge
would
be
impacted
to
a
lesser
degree
due
to
the
attenuation
of
noise
with
distance.
Draft
EIR
Section
4.J,
Noise
and
Vibration
,
analyzed
operational
noise
from
proposed
Baylands
development,
and
Brisbane
Baylands
Final
EIR
2.9.3-96
May
2015