2.
Response
to
Comments
2.9
Individual
Responses
to
Comments
from
Organizations
The
geology
underneath
the
railyard
west
of
the
landfill
is
not
uniform.
The
variability
exists
in
both
the
fill
and
the
native
composition
of
the
earth.
This
is
not
unexpected
due
to
depositional
effects
of
the
San
Francisco
Bay
and
the
resulting
geologic
upheavals
from
earthquakes.
Thus,
effects
on
the
lower
aquitard
outside
of
the
landfill
area
may
be
different
than
at
the
landfill
itself.
Draft
EIR
Table
4.E-1
identifies
the
age
of
“Young
Bay
Mud”
as
dating
to
the
Holocene
age
(less
than
11,000
years
old).
Artificial
fill,
including
rubble
from
the
1906
earthquake,
was
placed
on
Young
Bay
Mud
to
create
the
Baylands.
This
comment
quotes
a
portion
of
a
sentence
on
Draft
EIR
4.G-
18,
which
states
in
full
“Although
the
maximum
concentration
of
chromium
in
the
San
Mateo
County
is
below
the
regional
screening
level
for
total
chromium,
testing
for
hexavalent
chromium
had
not
been
conducted
at
this
location.”
Typically
hexavalent
chromium
is
analyzed
only
when
the
prior
use
of
the
site
is
metal
plating,
which
it
was
not.
However,
even
though
hexavalent
chromium
has
not
been
analyzed,
it
will
still
be
assessed
in
the
required
human
health
risk
assessment
pursuant
to
DTSC
standards.
This
comment
refers
to
previously
proposed
risk-based
cleanup
levels
proposed
by
MACTEC
for
in
2009,
but
never
adopted.
See
for
discussion
of
the
remediation
review
process.
Based
on
the
land
uses
approved
by
the
City
of
Brisbane,
updated
human
health
risk
assessments
will
be
prepared.
These
human
health
risk
assessments
will
then
be
used
by
the
RWQCB
and
DTSC
to
set
site-specific
risk-
based
cleanup
goals
for
the
Baylands.
The
complete
sentence
on
Draft
EIR
page
4.G-
18
that
is
referred
to
in
this
comment
states
“The
January
2009
cleanup
levels
recommended
by
MACTEC
for
the
constituents
of
concern
in
soil
at
are
presented
below.”
It
is
important
to
note
that
these
cleanup
levels
were
a
proposed
forwarded
by
the
landowner,
and
were
not
adopted
by
the
regulatory
agency.
See
for
discussion
regarding
the
remediation
review
and
approval
process
for
the
Baylands.
Based
on
the
land
uses
approved
by
the
City
of
Brisbane,
updated
human
health
risk
assessments
will
be
prepared.
These
human
health
risk
assessments
will
then
be
used
by
the
RWQCB
and
DTSC
to
set
site-specific
risk-based
cleanup
goals
for
the
Baylands.
There
is
no
factual
basis
provided
is
this
comment
to
support
its
assertion.
The
Draft
EIR
text
to
which
this
comment
Brisbane
Baylands
Final
EIR
2.9.1-35
May
2015