2.
Response
to
Comments
2.9
Individual
Responses
to
Comments
from
Organizations
by
either
the
RWQCB
or
DTSC.
Such
approvals
will
not
occur
until
after
the
City
of
Brisbane
approves
land
uses
for
the
Baylands,
updated
human
health
risk
assessments
are
completed
based
on
those
land
uses,
and
risk-based
cleanup
goals
are
established
by
the
RWQCB
and
DTSC.
The
Draft
EIR
text
referenced
in
this
comment
notes
that
estimates
of
21-26
feet
of
settlement
within
the
former
landfill
determined
by
Geosyntec
(2008)
assumed
use
of
wick
drains
to
facilitate
primary
settlement
in
Young
and
Old
Bay
Mud
and
secondary
settlement
of
municipal
waste
after
use
of
deep
dynamic
compaction.
Thus,
use
of
wick
drains
was
used
for
estimation
purposes
only.
Wick
drains
are
not
specifically
proposed,
nor
has
the
RWQCB
approved
any
specific
technologies
for
Title
27
closure
of
the
former
landfill.
Deep
dynamic
compaction
consists
of
the
use
of
heavy
equipment
to
systematically
and
repeatedly
drop
a
large
weight
onto
the
ground
in
order
to
condense
the
underlying
materials
to
a
density
suitable
for
the
proposed
structure.
Prior
to
commencement
of
any
deep
dynamic
compaction
activities
that
may
be
proposed,
a
site
specific
geotechnical
investigation
as
required
by
Draft
EIR
Mitigation
Measure
4.E-2a
would
be
undertaken
to
provide
a
detailed
understanding
of
the
underlying
materials
and
recommendations
for
site
preparation
methods.
These
recommendations
would
be
in
accordance
with
industry
standard
practices
and
building
code
standards
that
are
subject
to
review
by
the
City
Engineer,
and
would
be
required
to
be
implemented
as
part
of
site
preparation
and
grading.
Deep
dynamic
compaction
is
not
the
only
option
available
for
building
foundation
design
and
would
only
be
employed
where
appropriate
as
determined
by
site-specific
data
following
review
and
approval
by
the
City
building
official.
Part
of
the
consideration
for
employing
this
strategy
is
the
potential
effects
on
neighboring
sites
such
that
the
process
does
not
cause
instability
of
the
Bay
Mud
or
adjoining
exposed
slopes,
for
example.
Deep
dynamic
compaction
and
other
methods
of
site
preparations
such
as
surcharging
with
stockpiled
soils
have
been
used
successfully
at
numerous
sites
with
similar
underlying
Bay
Mud
deposits
to
provide
adequate
building
sites
without
causing
underlying
Bay
Mud
soils
to
fail.
To
clarify
its
intent,
Mitigation
Measure
4.E-2a
is
revised
to
read
as
follows:
Mitigation
Measure
4.E-2a:
Prior
to
the
issuance
of
a
grading
permit,
applicants
for
all
site-specific
development
and
infrastructure
projects
within
the
Project
Site,
including
structures,
utilities,
and
roadways
shall
submit
to
the
City
Engineer
a
final
design-level
geotechnical
report
prepared
by
a
licensed
geotechnical
or
soil
engineer
experienced
in
construction
methods
on
fill
materials
in
an
active
seismic
area.
The
report
shall
provide
site-specific
construction
methods
and
recommendations
regarding
grading
activities,
fill
placement,
soil
corrosivity/expansion/erosion
potential,
compaction,
foundation
Brisbane
Baylands
Final
EIR
2.9.1-26
May
2015