Document ID: EPA-HQ-RCRA-2002-0029-0013
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2003-01-29T05:00Z

Peer
Review
Comments
on:

Technical
Background
Document:
Mercury
Wastes
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury
and
Technical
Background
Document:
Mercury
Wastes
Evaluation
of
Treatment
of
Mercury
Surrogate
Waste
July
9,
2002
Submitted
by:

Bill
Batchelor
614
East
29th
Street
Bryan,
Texas
77803
Submitted
to:

Science
Applications
International
Corporation
Engineering
and
Environmental
Management
Group
11251
Roger
Bacon
Drive
Reston,
Virginia
20190
and
U.
S.
Environmental
Protection
Agency
Ariel
Rios
Building
Office
of
Solid
Waste
1200
Pennsylvania
Avenue,
N.
W.
Washington,
D.
C.
20460
EPA
Contract
No.
68­
W0­
1022
Work
Assignment
No.
0­
2
SAIC
Project
No.
06­
0758­
08­
4042­
000
2
Review
of
Mercury
Treatability
Studies
by
Bill
Batchelor
614
East
29th
Street
Bryan,
Texas
77803
July
9,
2002
Review
of
"
Evaluation
of
Mercury
Surrogate
Waste"

1.
Was
the
experimental
design
of
the
study
appropriate?

The
experimental
design
employed
was
appropriate
in
most
regards.
One
problem
with
the
plan
was
the
variability
introduced
by
having
vendors
prepare
the
surrogate
waste.
Data
in
Appendix
C
shows
that
concentrations
of
potassium,
calcium
and
magnesium
were
much
higher
in
the
surrogates
prepared
by
all
vendors
than
the
surrogate
prepared
by
Alter.
Furthermore,
the
concentrations
of
chloride
in
surrogate
waste
prepared
by
Vendors
A,
B,
and
C
were
much
higher
than
concentrations
in
the
surrogate
prepared
by
Alter
and
Vendor
D.
Chloride
concentrations
are
particularly
important
because
of
the
ability
of
chloride
ions
to
form
soluble
complexes
with
mercury,
thereby
enhancing
its
release
during
leaching
tests.
Therefore,
it
is
possible
that
the
surrogate
waste
treated
by
Vendor
D
was
"
easier"
to
treat,
than
that
treated
by
the
other
vendors.
Vendor
C
reported
using
only
about
one
half
of
the
specified
water
in
preparing
its
surrogate
waste.
The
effect
of
reduced
water
content
in
the
surrogate
waste
on
performance
in
leaching
tests
is
not
clear,
but
the
lack
of
consistency
in
surrogate
waste
preparation
is
undesirable.
3
2.
Was
the
study
conducted
properly?

The
conduct
of
the
study
appears
to
have
been
proper.

3.
Were
the
stated
objectives
adequately
met?
(
Please
note
that
we
are
asking
you
to
focus
your
response
son
the
stated
objective
listed
above
and
not
necessarily
on
all
the
objectives
stated
in
the
body
of
each
study
report.)

a)
Effectiveness
of
meeting
goal
of
0.025
mg/
L
in
leaching
tests
i)
TCLP
Test
The
treatment
process
of
Vendor
A
was
able
to
consistently
meet
the
goal
(
0.025
mg/
L)
in
the
TCLP
test
by
substantial
margin
(
concentrations
<
0.01
mg/
L).
There
was
little,
if
any,

difference
between
the
treated
materials
in
crushed
or
pellet
forms.
The
ability
of
this
treated
waste
to
meet
the
goal
was
confirmed
by
its
performance
in
the
constant
pH
leaching
test
(
CPLT),
in
which
concentrations
were
measured
below
the
goal
at
pH
values
near
that
observed
in
the
TCLP.

The
treatment
process
of
Vendor
B
was
not
able
to
meet
the
goal
in
any
samples
submitted.
This
performance
was
confirmed
by
the
CPLT.

The
treatment
process
of
Vendor
C
was
able
to
meet
the
treatment
goal
in
all
samples
submitted
(
Batch
1,
Batch
2).
The
degree
by
which
the
goal
was
exceeded
was
greater
in
Batch
2
than
Batch
1.
This
behavior
was
confirmed
by
performance
in
the
CPLT,
although
concentrations
were
higher
in
the
CPLT.
4
The
treatment
process
of
Vendor
D
was
able
to
meet
the
treatment
goal
in
one
sample
submitted
(
Batch
1),
but
did
not
meet
the
treatment
goal
in
another
sample
(
Batch
2).
The
average
TCLP
concentration
for
Batch
2
exceeded
the
goal,
although
one
sub­
sample
out
of
three
was
lower
than
the
treatment
goal.
This
performance
was
confirmed
by
performance
of
Batch
#
2
in
the
CPLT.
However,
Batch
#
1
gave
a
very
high
concentration
in
the
CPLT
near
the
pH
of
the
TCLP.
However,
this
point
does
not
follow
the
general
trend
of
the
rest
of
the
data
for
this
treated
waste
or
the
treated
wastes
of
other
vendors,
so
it
appears
to
be
an
outlier.

These
results
support
the
conclusion
that
there
are
existing
stabilization
technologies
that
can
meet
a
TCLP
goal
of
0.025
mg/
L
in
wastes
with
mercury
concentrations
well
in
excess
of
260
mg/
kg.

ii)
Constant
pH
test
Only
a
few
(
pH
2,
8,
12)
CPLT
were
replicated,
so
there
is
limited
data
to
evaluate
the
reproducibility
of
the
test
procedure.
The
average
relative
percentage
difference
(
RPD)
for
all
vendors
was
35%,
but
many
individual
RPD
exceeded
100%.
This
limits
the
confidence
that
can
be
placed
on
individual
test
results,
especially
when
they
approach
the
treatment
goal.

The
treatment
process
of
Vendor
A
was
able
to
meet
the
treatment
goal
at
all
pH
values
except
pH
12.
All
samples
meeting
the
goal
did
so
by
a
substantial
margin
(
concentration
<
0.01
mg/
L),

except
one
of
the
duplicates
at
pH
8.
5
The
treatment
process
of
Vendor
B
was
not
able
to
meet
the
treatment
goal
at
any
pH
values,

except
for
both
duplicates
of
one
sample
(
Phase
II,
pH
12).

The
treatment
process
of
Vendor
C
was
able
to
meet
the
goal
under
some
conditions.
In
general,

the
goal
could
be
met
at
higher
pH
and
in
Batch
#
2.
Both
duplicates
met
the
treatment
goal
in
Batch
#
2
at
pH
8,
but
only
one
met
the
goal
in
Batch
#
1
at
that
pH.
Both
duplicates
met
the
treatment
goal
in
Batch
#
2
at
pH
12,
but
neither
did
in
Batch
#
1
at
that
pH.
The
variability
in
performance
between
batches
shown
by
the
treatment
process
of
Vendor
C
is
not
substantially
different
from
that
shown
by
treatment
processes
of
other
vendors.
However,
the
treated
waste
provided
by
Vendor
C
produced
concentrations
in
the
CPLT
that
were
near
the
treatment
goal,
so
that
there
was
more
variation
in
whether
a
particular
sample
met
the
goal.
The
variability
in
performance
of
all
treated
wastes
indicates
the
problems
of
heterogeneity
of
the
waste
and/
or
variability
in
application
of
the
treatment
process
The
treatment
process
of
Vendor
D
was
not
able
to
meet
the
goal,
except
at
higher
pH.
At
pH
12,
three
samples
met
the
goal
and
one
sample
was
at
the
goal
(
0.025
mg/
L).
However,
none
of
the
samples
at
pH
12
exceeded
the
goal
by
a
substantial
margin
(<
0.01
mg/
L).

b)
Comparison
of
TCLP
to
constant
pH
leach
test
(
CPLT).

The
CPLT
is
similar
to
the
TCLP,
but
it
does
not
duplicate
all
conditions
of
the
TCLP.
In
addition
to
operating
at
different
pH,
the
CPLT
has
a
longer
leaching
time
(
14
days
compared
to
18
hours),
different
L/
S
ratio
(
20
L/
kg
dry
mass
compared
to
20
L/
kg
total
mass)
and
uses
a
different
leaching
solution
(
mixture
of
nitric
acid
and/
or
sodium
hydroxide
compared
to
acetic
6
acid
and
possibly
sodium
hydroxide).
These
differences
can
lead
to
observing
higher
or
lower
concentrations
in
the
CPLT
compared
to
those
measured
in
the
TCLP,
even
when
the
CPLT
is
at
the
pH
observed
in
the
TCLP.
Using
a
L/
S
ratio
defined
in
terms
of
dry
mass
rather
than
total
mass
will
result
in
a
greater
amount
of
waste
being
used
in
the
CPLT
per
unit
volume
of
leachate
compared
to
the
TCLP.
This
would
tend
to
lead
to
higher
concentrations
being
measured
in
the
CPLT.
A
longer
leaching
time
in
the
CPLT
would
tend
to
result
in
the
leaching
solution
approaching
more
closely
to
equilibrium
conditions
with
the
solids.
This
could
result
in
higher
or
lower
concentrations
being
observed,
because
concentrations
in
the
TCLP
test
can
be
increasing
or
decreasing
as
the
end
of
the
leaching
period
approaches.
Concentrations
would
tend
to
continuously
increase
for
components
whose
solubility
is
not
strongly
affected
by
pH
or
when
the
pH
of
the
leaching
fluid
does
not
change
appreciably.
However,
concentrations
of
compounds
that
are
strongly
affected
by
pH
would
tend
to
increase
initially
when
pH
is
low
and
then
decrease
as
pH
rises
in
the
leaching
fluid.
The
presence
of
nitrate
rather
than
acetic
acid/
acetate
could
affect
leaching
results
when
one
or
the
other
of
these
compounds
forms
stronger
complexes
with
a
metal
being
extracted.

The
treated
waste
provided
by
Vendor
A
showed
concentrations
in
the
TCLP
to
be
similar,
but
lower
than
concentrations
in
the
CPLT
when
interpolated
to
the
pH
of
the
TCLP.
However,
the
constant
pH
test
resulted
in
some
concentrations
at
other
pH
values
that
were
much
higher
than
observed
for
the
TCLP
at
pH
values
different
from
that
observed
in
the
TCLP.

The
treated
waste
provided
by
Vendor
B
showed
good
agreement
in
concentrations
measured
in
the
TCLP
and
in
the
CPLT,
when
concentrations
in
the
CPLT
are
interpolated
to
the
pH
of
the
7
TCLP.
However,
the
CPLT
resulted
in
some
concentrations
that
were
higher
and
lower
than
those
measured
in
the
TCLP,
when
measured
at
pH
values
different
from
those
observed
in
the
TCLP.

The
treated
waste
provided
by
Vendor
C
showed
similar
concentrations
measured
in
the
TCLP
and
in
the
CPLT,
when
concentrations
in
the
CPLT
are
interpolated
to
the
pH
of
the
TCLP.

However,
the
interpolated
concentrations
of
the
CPLT
tended
to
be
higher
than
those
in
the
TCLP.
However,
the
CPLT
resulted
in
some
concentrations
that
were
much
higher
than
those
observed
for
the
TCLP
at
pH
values
different
from
those
observed
in
the
TCLP.

The
treated
waste
provided
by
Vendor
D
showed
similar
concentrations
in
both
leach
tests,
when
compared
at
the
same
pH
and
when
the
result
in
the
CPLT
at
pH
10
for
Batch
#
1
is
considered
an
outlier.
This
point
should
be
considered
an
outlier
because
it
is
much
higher
than
the
general
trend
at
other
pH
values
for
Batch
#
1
and
very
different
from
that
observed
for
Batch
#
2
at
pH
10.
The
CPLT
resulted
in
some
concentrations
that
were
much
higher
than
those
observed
for
the
TCLP
at
pH
values
different
from
those
observed
in
the
TCLP.

In
general,
the
two
test
procedures
provided
similar
results
when
compared
at
the
same
pH.
In
some
cases,
the
concentrations
measured
in
the
TCLP
tended
to
be
a
little
lower
than
those
observed
by
interpolating
concentrations
measured
in
the
CPLT
to
the
pH
of
the
TCLP.
This
could
be
due
to
the
fact
that
the
TCLP
has
a
higher
effective
L/
S
and
shorter
leaching
time
than
the
CPLT.
The
CPLT
also
produced
concentrations
at
other
pH
values
that
could
be
much
higher
than
those
measured
in
the
TCLP.
8
Review
of
"
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury"

1.
Was
the
experimental
design
of
the
study
appropriate?

The
experimental
design
was
generally
appropriate.
One
exception
was
the
failure
to
confirm
that
waste
loadings
(
elemental
mercury
loadings)
were
as
reported
by
the
vendors.
The
report
does
not
present
any
data
supporting
the
reported
waste
loadings.
The
experimental
plan
calls
for
mercury
concentrations
in
the
waste
forms
to
be
determined,
but
these
data
are
not
presented.

These
concentrations
would
be
a
check
on
the
reported
waste
loadings
and
should
be
reported.

Identifying
the
concentrations
of
mercury
in
the
waste
forms
among
the
raw
data
in
Appendix
B
is
difficult.
However,
an
attempt
was
made
to
identify
these
concentrations
and
it
appears
that
the
mercury
contents
of
treated
solids
from
some
vendors
were
much
lower
than
expected
from
reported
waste
loadings.
The
highest
concentration
reported
for
a
solid
from
vendor
A
(
samples
01
to
10,
p
B­
98)
is
16,400
mg/
kg,
compared
to
a
concentration
of
330,000
mg/
kg
expected
from
the
reported
waste
loading
of
33%.
The
highest
concentration
found
for
a
solid
treated
by
Vendor
B
(
samples
34
to
43
on
p
B­
154,
B­
155)
is
285,000
mg/
kg
compared
to
concentrations
of
550,000
mg/
kg
and
440,000
mg/
kg
expected
for
waste
loadings
of
55%
(
Phase
I)
and
44%

(
Phase
II).
Other
concentrations
are
reported
in
this
group
that
are
much
lower.
The
highest
concentration
found
for
a
solid
treated
by
Vendor
C
is
10,700
mg/
kg
(
samples
9
to
13,
p.
B­
67)

compared
to
a
concentration
of
201,000
mg/
kg
expected
for
a
waste
loading
of
20.1%.

Recoveries
of
metals
from
treated
wastes
are
often
less
than
expected.
Low
recoveries
can
be
the
result
of
inadequate
analytical
procedures
for
measuring
metals
in
solids
that
have
been
9
treated
with
the
intent
to
reduce
the
availability
of
the
metal.
No
information
was
given
concerning
the
dissolution
procedures
used
on
the
treated
wastes
to
solubilize
mercury
prior
to
analysis.
The
only
procedure
specified
(
SW
846
Method
7470A)
is
a
method
for
analyzing
mercury
in
aqueous
solutions.
Therefore,
there
is
no
way
to
determine
if
the
dissolution
procedure
could
be
expected
to
reliably
recover
mercury.
Regardless
of
the
reason
for
the
low
recoveries
for
treated
wastes
submitted
by
Vendors
A
and
C,
they
are
so
low
that
they
cast
doubt
on
the
meaningfulness
of
the
results
of
leaching
tests.

2.
Was
the
study
conducted
properly?

The
study
was
conducted
properly,
with
the
exception
of
assuring
that
waste
loadings
were
as
reported
by
the
vendors.

3.
Were
the
stated
objectives
adequately
met?
(
Please
note
that
we
are
asking
you
to
focus
your
response
son
the
stated
objective
listed
above
and
not
necessarily
on
all
the
objectives
stated
in
the
body
of
each
study
report.)

a)
Effectiveness
of
meeting
goal
of
0.025
mg/
L
in
leaching
tests
i)
TCLP
Test
The
treated
material
prepared
by
Vendor
A
did
not
generally
meet
the
goal
of
0.025
mg/
L
mercury
in
the
TCLP
test,
although
one
sample
of
the
palletized
material
met
the
goal
by
a
small
margin.
This
behavior
was
generally
confirmed
by
the
CPLT,
which
showed
similar,
but
generally
higher,
concentrations
interpolated
to
the
pH
values
measured
in
the
TCLP.
10
The
treated
material
prepared
by
Vendor
B
did
meet
the
treatment
goal
and
it
did
so
by
a
substantial
margin
(
all
concentrations
below
0.01
mg/
L).
The
total
mercury
analysis
for
the
material
supplied
by
this
vendor
may
have
been
high
enough
to
support
the
reported
waste
loading
(
see
response
to
question
1,
above).
The
behavior
in
the
TCLP
was
supported
by
similar
behavior
in
the
CPLT
near
the
pH
of
the
TCLP
test.

The
treated
material
prepared
by
Vendor
C
did
meet
the
TCLP
goal,
but
not
by
a
substantial
margin.
Concentrations
measured
in
all
samples
were
below
0.025
mg/
L,
but
above
0.010
mg/
L.

However,
the
reproducibility
was
very
good,
with
a
coefficient
of
determination
of
9%.
The
behavior
in
the
TCLP
was
partially
confirmed
by
the
CPLT.
The
concentration
at
the
TCLP
pH
(
pH
6.7)
interpolated
from
data
from
the
CPLT
was
similar,
but
somewhat
higher.
The
interpolated
concentration
in
the
CPLT
was
strongly
influenced
by
the
CPLT
data
point
at
pH
6,

which
was
somewhat
lower
than
those
measured
at
pH
4
and
pH
8.
The
ability
of
this
treated
material
to
reliably
pass
the
TCLP
goal
is
also
brought
into
question
by
indications
that
concentrations
of
total
mercury
may
have
been
measured
in
the
treated
material
that
are
much
lower
than
what
would
be
expected
from
the
reported
waste
loading
(
see
response
to
question
1,

above).

ii)
Constant
pH
test
The
treated
material
prepared
by
Vendor
A
did
not
meet
the
goal
of
0.025
mg/
L
in
the
CPLT
except
at
pH
2
(
pellets
and
crushed
samples)
and
pH
11
(
pellets).
The
behavior
in
the
CPLT
was
generally
confirmed
by
that
in
the
TCLP
when
concentrations
are
compared
near
the
pH
of
the
11
TCLP.
However,
interpolated
concentrations
in
the
CPLT
tended
to
be
generally
higher
than
those
measured
in
the
TCLP.

The
treated
material
prepared
by
Vendor
B
did
meet
the
goal
in
the
CPLT,
except
at
pH
12.
The
behavior
in
the
CPLT
was
generally
confirmed
by
that
in
the
TCLP
when
compared
by
interpolating
CPLT
data
to
the
pH
of
the
TCLP.

The
treated
material
prepared
by
Vendor
C
generally
did
not
meet
the
goal
in
the
CPLT.
Two
samples
at
pH
12
had
concentrations
(
0.0251
mg/
L
and
0.0249
mg/
L)
that
were
substantially
the
same
as
the
treatment
goal.
The
concentrations
measured
in
the
TCLP
at
pH
6.7
were
similar
to
that
measured
in
the
CPLT
at
pH
6,
but
substantially
lower
than
that
measured
at
pH
8.

General
Comments
1.
Are
you
aware
of
any
other
data/
studies
that
are
relevant
to
the
assessment
of
stabilized
mercury­
bearing
wastes
and
the
behavior
of
these
wastes
in
the
environment?

The
following
articles
are
relevant
to
this
topic.

"
Stabilization/
solidification
(
S/
S)
of
mercury­
containing
wastes
using
reactivated
carbon
and
Portland
cement",
Zhang,
Jian;
Bishop,
Paul
L.
Journal
of
Hazardous
Materials
(
2002),
92(
2),
199­
212.
"
Sulfide­
induced
stabilization
and
leachability
studies
of
mercury
containing
wastes",
Piao,
Haishan;
Bishop,
Paul,
Abstracts
of
Papers,
223rd
ACS
National
Meeting,
Orlando,
FL,
United
States,
April
7­
11,
2002
(
2002),
ENVR­
207.
"
Phosphate­
induced
mercury
stabilization",
Zhang,
Jian;
Bishop,
Paul
L.,
Preprints
of
Extended
Abstracts
presented
at
the
ACS
National
Meeting,
American
Chemical
Society,
Division
of
Environmental
Chemistry
(
2001),
41(
1),
422­
424.
"
Sulfide­
induced
mercury
stabilization",
Piao,
Haishan;
Bishop,
Paul
L.,
Preprints
of
Extended
Abstracts
presented
at
the
ACS
National
Meeting,
American
Chemical
Society,
Division
of
Environmental
Chemistry
(
2001),
41(
1),
428­
431.
"
Stabilization
of
radioactively
contaminated
elemental
mercury
wastes",
Stewart,
Robin;
Broderick,
Tom;
Litz,
John;
Brown,
Cliff;
Faucette,
Andrea.,
Proceedings
of
the
12
International
Conference
on
Decommissioning
and
Decontamination
and
on
Nuclear
and
Hazardous
Waste
Management,
Denver,
Sept.
13­
18,
1998
(
1998),
3
33­
36.
"
Mercury
stabilization
in
chemically
bonded
phosphate
ceramics",
Wagh,
Arun
S.;
Jeong,
Seung­
Young;
Singh,
Dileep,
Ceramic
Transactions
(
1998),
87(
Environmental
Issues
and
Waste
Management
Technologies
in
the
Ceramic
and
Nuclear
Industries
III),
63­
73.
"
A
Framework
for
Risk
Assessment
of
Disposal
of
Wastes
Treated
by
Solidification/
Stabilization",
Batchelor,
B.,
Environmental
Engineering
Science,
14(
1):
3­
13,
1997.
"
A
study
of
immobilization
of
four
heavy
metals
by
solidification/
stabilizatioin
with
Portland
cement",
Susan
A.
Trussell,
Ph.
D.
Dissertation,
Texas
A&
M
Univeristy,
College
Station,
Texas,
1994.
"
Immobilization
of
chromium
and
mercury
from
industrial
wastes",
Wasay,
S.
A.;
Das,
H.
A.
,
J.
Environ.
Sci.
Health,
Part
A
(
1993),
A28(
2),
285­
97.
Chemical
Fixation
and
Solidification
of
Hazardous
Wastes,
Jesse
R.
Conner,
Van
Nostrand
Reinhold,
New
York,
1990.
"
An
investigation
of
mercury
solidification
and
stabilization
in
portland
cement
using
x­
ray
photoelectron
spectroscopy
and
energy
dispersive
spectroscopy",
McWhinney,
Hylton
G.;
Cocke,
David
L.;
Balke,
Karl;
Ortego,
J.
Dale.,
Cem.
Concr.
Res.
(
1990),
20(
1),
79­
91.
"
Studies
of
zinc,
cadmium
and
mercury
stabilization
in
OPC/
PFA
mixtures",
Poon,
C.
S.;
Perry,
R.,
Mater.
Res.
Soc.
Symp.
Proc.
(
1987),
86(
Fly
Ash
Coal
Convers.
By­
Prod.),
67­
76.
"
Permeability
study
on
the
cement
based
solidification
process
for
the
disposal
of
hazardous
wastes",
Poon,
C.
S.;
Clark,
A.
I.;
Perry,
R.;
Barker,
A.
P.;
Barnes,
P.,
Cem.
Concr.
Res.
(
1986),
16(
2),
161­
72.
"
Mechanisms
of
metal
fixation
and
leaching
by
cement
based
fixation
processes",
Poon,
C.
S.;
Clark,
A.
I.;
Peters,
C.
J.;
Perry,
R.,
Waste
Manage.
Res.
(
1985),
3(
2),
127­
42.
"
Mechanisms
of
metal
stabilization
by
cement
based
fixation
processes",
Poon,
C.
S.;
Peters,
C.
J.;
Perry,
R.;
Barnes,
P.;
Barker,
A.
P.,
Sci.
Total
Environ.
(
1985),
41(
1),
55­
71.

Additionally,
a
database
is
being
prepared
that
will
contain
information
on
many
characteristics
of
wastes.
This
will
include
those
containing
mercury.
The
final
report
has
not
been
prepared
but
information
is
available
at
http://
www.
concrete.
cv.
ic.
ac.
uk/
iscowaa/
nnapics/
intro.
html
2.
With
regard
to
the
disposal
of
treated
mercury
wastes,
are
additional
studies
warranted
for
other
factors
that
impact
solubility
(
e.
g.,
liquid/
solid
ratio,
redox
conditions,
leachate
composition)
or
affect
ability
to
leach,
such
as
use
of
macroencapsulation?
If
you
believe
that
additional
studies
are
needed
,
please
explain
why.
13
These
studies
have
adequately
demonstrated
that
a
goal
of
0.025
mg/
L
in
the
TCLP
can
be
met
by
existing
stabilization
technologies,
both
for
a
surrogate
waste
containing
various
forms
of
mercury
at
a
total
concentration
of
5,000
mg/
kg
and
for
elemental
mercury.
However,
meeting
this
goal
does
not
insure
that
adequate
protection
of
human
health
and
the
enviornment
is
assured
for
all
conditions
of
waste
disposal.
However,
this
statement
is
not
limited
to
mercury
wastes,
but
is
a
limitation
of
the
TCLP
for
all
hazardous
constituents.
Therefore,
additional
studies
are
not
warranted
to
determine
if
existing
technologies
can
meet
a
TCLP
goal
of
0.025
mg/
L
for
wastes
that
contain
mercury
at
concentrations
above
260
mg/
kg.
However,
additional
studies
are
warranted
to
develop
characterization
methods
and
analytical
techniques
that
will
insure
safe
disposal
of
hazardous
wastes
containing
toxic
materials
including
mercury
under
a
range
of
site­
specific
disposal
conditions.

3.
Do
you
agree
that
the
following
statements
are
supported
by
the
research
results?

a.
Site
specific
disposal
conditions
must
be
considered
along
with
appropriate
treatment
technology
as
decisions
are
made
about
disposal
of
mercury
wastes.

These
research
results
do
support
this
statement,
because
they
demonstrate
that
pH
can
have
an
important
impact
on
the
amount
of
mercury
leached
from
treated
wastes.
The
pH
of
a
leaching
fluid
can
be
very
different
under
different
disposal
conditions.
However,
the
research
results
do
not
prove
the
statement,
because
there
could
be
conditions
under
which
a
waste
could
be
characterized
so
that
site­
specific
disposal
conditions
would
not
be
required
to
insure
a
reasonable
degree
of
confidence
in
protection
of
human
health
and
the
environment.
14
b.
The
presence
of
chloride
ions
in
a
given
disposal
environment
may
significantly
impact
the
release
from
a
treated
waste
form
(
mercury
selenide).

This
statement
is
supported
by
the
research
results,
because
a
leaching
solution
with
500
mg/
L
chloride
did
result
in
higher
concentrations
of
mercury
being
leached
at
pH
7
and
10.
However,

the
data
reported
is
not
sufficient
to
conclude
that
chloride
will
(
rather
than
may)
significantly
impact
release
of
mercury
under
a
range
of
disposal
conditions.
Sufficient
data
exists
on
formation
of
mercury­
chloride
soluble
complexes
to
strongly
suggest
that
chloride
will
tend
to
increase
mercury
release,
but
specific
conclusions
on
the
impact
of
particular
levels
of
chloride
in
different
disposal
scenarios
would
require
additional
research.

4.
Any
additional
comments?

The
following
corrections
should
be
made
to
the
reports.

a)
"
Evaluation
of
Mercury
Surrogate
Waste"
(
various
places)
The
relationship
of
ALTER
and
the
University
of
Cincinnati
should
be
clarified.
It
appears
that
the
two
are
used
interchangeably.
This
comment
also
applies
to
"
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury".
(
p.
2­
5,
bullet
3)
should
be
"<
260
ppm"
(
p.
3­
4,
line
5
from
bottom
and
elsewhere)
Provide
units
for
liquid/
solid
ratio.
This
comment
also
applies
to
"
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury".
(
p.
5­
1,
Table
5­
1
and
others)
Percentages
should
be
reported
with
no
more
significant
digits
than
the
measurements
upon
which
they
are
based.
This
comment
also
applies
to
"
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury".
(
p.
5­
1,
Table
5­
1
and
others)
The
leaching
fluid
used
in
the
TCLP
tests
should
be
specified.
This
comment
also
applies
to
"
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury".
(
p.
5­
5,
Table
5­
4,
columns
2,3,6,7)
Replace
"
3/
4"
with
blank
or
other
indication
that
presenting
the
percent
leached
is
not
appropriate
for
a
blank.

b)
"
Evaluation
of
Treatment
of
Bulk
Elemental
Mercury"
(
p.
3­
2)
It
would
be
helpful
to
the
reader
to
make
more
clear
here
that
the
"
waste"
being
treated
is
elemental
mercury.
(
p.
5­
4,
Table
5­
3)
Standard
deviation
of
TCLP
results
for
Phase
II
should
be
0.00160.
(
p.
5­
6,
Figure
5­
3)
TCLP
data
are
missing
from
this
figure.