Document ID: EPA-HQ-RCRA-2006-0097-0085
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-05-25T04:00Z

Review
of:
Report
on
Potential
Risks
Associated
with
the
Use
of
Chat
from
Tri­
State
Area
in
Transportation
Projects
Response
to
Charge
Questions:

1.
Are
you
aware
of
any
other
data/
studies
that
are
relevant,
particularly
with
respect
to
air
emissions
from
either
transportation,
construction
projects,
or
demolition
that
could
be
included
in
the
evaluation?

Overall,
the
report
does
a
good
job
compiling
and
summarizing
the
available
relevant
information
as
well
as
identifying
shortcomings
and
gaps
in
knowledge.
With
respect
to
emissions
specifically
related
to
transportation,
construction
projects
or
demolition,
I
have
seen
none
that
are
specifically
related
to
the
Tar
Creek
area.

Several
other
documents
may
be
of
use
with
respect
to
the
raw
chat
material:

K.
D.
Drake,
1999.
Leachability
of
Size­
Fractionated
Mine
Tailings
from
the
Kansas
portion
of
the
Tri­
State
Mining
Area.
M.
S.
thesis,
University
of
Missouri­
Kansas
City.

This
thesis
presents
total
metal
concentrations
and
TCLP
results
for
size­
fractionated
raw
chat.
There
are
also
some
results
regarding
the
mineralogy
of
Zn
in
the
chat
using
x­
ray
diffraction.

S.
Magoo
and
S.
L.
Yarbrough.
1996.
Draft
 
Final
Site
Evaluation
Findings
Report,
Tar
Creek
NPL
Site,
Oklahoma
City
Field
Area.

This
report
contains
analyses
of
size­
fractionated
raw
chat,
including
total
metal
concentrations
and
the
results
of
SPLP
(
synthetic
precipitation
leaching
protocol)
tests.
The
report
also
presents
size­
fractionated
Pb
concentrations
and
mineralogical
analyses
in
yard
soils.

The
following
report
contains
an
assessment
of
metals
in
runoff
from
chat
piles:

OWRB.
1983.
Water
Quality
Characteristics
of
Seepage
and
Runoff
at
Two
Tailings
Piles
in
the
Picher
Field,
Ottawa
County,
Oklahoma.
Tar
Creek
Field
Investigation,
Task
1.2.

This
report
presents
total
metal
concentrations
in
the
runoff
from
two
chat
piles,
all
of
which
are
highly
elevated
compared
to
background
concentrations,
and
thus
provides
a
sense
of
in­
field
mobility
of
metals
in
raw
chat.

There
are
also
two
journal
articles
that
assess
the
major
routes
of
exposure
to
metals
by
children
in
the
Picher
area:
2
Lynch,
RA,
LH
Malcoe,
VJ
Skaggs
and
MC
Kegler.
2000.
The
relationship
between
residential
lead
exposures
and
elevated
blood
lead
levels
in
a
rural
mining
community.
Journal
of
Environmental
Health.
63(
3):
9­
15.

Malcoe,
LH,
RA
Lynch,
MC
Kegler
and
VJ
Skaggs.
2002.
Lead
sources,
behaviors,
and
socioeconomic
factors
in
relation
to
blood
lead
of
Native
American
and
white
children:
A
community­
based
assessment
of
a
former
mining
area.
Environmental
Health
Perspectives.
110(
Suppl.
2):
221­
231.

In
addition,
there
are
two
academic
research
groups
conducting
experiments
applicable
to
this
review.
Dr.
Bob
Nairn
at
the
University
of
Oklahoma
has
been
conducting
experiments
on
the
use
of
chat
in
asphalt,
including
experiments
of
leaching
rates
into
road­
side
soils.
The
results
of
his
studies
would
be
particularly
applicable
for
this
document.
At
the
Harvard
School
of
Public
Health,
Dr.
Jim
Shine
has
an
ongoing
study
on
metal
speciation,
transport,
and
fate
of
metals
in
the
Tar
Creek
area.
Some
of
their
data
on
total
metal
concentrations
down
into
the
respirable
particle
size
range
(
i.
e.,
down
to
PM10
and
PM2.5
sizes),
as
well
as
on
the
speciation
of
metals
in
chat
and
differences
with
changes
in
particle
size,
would
have
been
helpful
in
this
analysis.
Unfortunately,
data
from
both
groups
have
not
been
published
at
this
time,
although
I
have
seen
them
presented
at
national
meetings.

2.
Does
the
report
present
the
available
data,
assumptions,
and
evaluation
in
a
complete
and
unbiased
manner?

Overall,
the
presentation
of
the
material
was
fairly
complete
and
presented
in
an
unbiased
manner.
The
authors
seemed
to
be
upfront
with
the
limitations
of
their
approach
and
were
clear
about
their
assumptions.

3.
Are
the
conclusions
concerning
environmental
release
and
potential
environmental
and
public
health
impacts,
including
the
limitations
and
uncertainties,
supported
by
the
available
data?
In
particular,
while
the
report
findings
relied
on
several
studies
that
followed
specific
data
quality
objectives
and
methodologies,
are
the
laboratory
and
field
data
of
sufficient
power
to
support
the
findings?

The
authors
discuss
in
depth
the
results
of
TCLP
tests
of
raw
chat
and
asphalt
materials.
While
the
TCLP
tests
do
provide
useful
information
and
a
starting
point
to
consider
metal
mobility
from
chat­
containing
materials,
additional
consideration
should
be
given
to
predicting
the
fate
of
these
materials
in
the
field.
I
have
several
concerns
with
solely
using
TCLP
data.

Short
duration
of
experiments.
TCLP
tests
only
last
18
hours
and
are
conducted
in
a
laboratory.
What
happens
over
months
and
years,
as
the
asphalt
material
chemically
and
physically
breaks
down,
and
at
potentially
higher
temperatures,
that
could
accelerate
weathering
reactions?
I
realize
that
no
data
are
readily
available
on
these
issues,
but
could
the
authors
speculate
about
3
how
these
results
might
extrapolate
to
the
field?
I
believe,
however,
that
the
group
at
the
University
of
Oklahoma
are
currently
conducting
these
types
of
experiments.

Long­
term
fate
of
metals.
The
TCLP
results
suggest
that
the
concentration
of
metals
in
leachate
from
the
asphalt
will
not
be
harmful.
But
where
do
these
metals
end
up
over
time?
If
year
after
year,
runoff
from
roads
passes
over
the
soils
along
the
sides
of
the
roads,
is
there
the
potential
to
accumulate
high
metal
concentrations
in
the
surface
of
soils?
Again,
these
data
probably
are
not
available,
but
can
a
worst­
case
scenario
of
accumulation
of
mobilized
metals
be
provided?
Alternatively,
can
one
examine
the
results
from
the
U
of
OK
group?

Other
pathways
of
metal
mobility.
Leaching
of
metals
into
water
may
not
be
the
only
mechanism
through
which
particles
are
released
to
the
environment.
Factors
such
as
physical
abrasion
by
road
traffic
may
also
be
important.

In
the
discussion
and
the
conceptual
model,
the
authors
seem
to
downplay
the
importance
of
inhalation
of
respirable
chat
particles
during
the
processing
(
e.
g.,
dry
sieving)
of
the
chat.
In
the
first
paragraph
of
section
3.1,
the
authors
assert
that
"
raw
chat
particle
sizes
are
generally
not
considered
in
the
respirable
range,"
but
the
work
of
ODEQ
(
2002)
shows
the
significant
enhancement
of
metal
concentrations
in
the
smallest
particles,
which
are
most
likely
the
ones
to
be
mobilized
offsite.
According
to
their
graphs,
around
3­
9%
of
chat
passed
through
the
#
200
sieve
(<
74
µ
m).
These
particles
are
small
enough
to
be
transported
by
wind
(
total
suspended
particles
are
defined
as
100
µ
m
or
smaller).
A
subset
of
these
particles
will
be
in
the
respirable
range
(<
10
µ
m).

In
general,
the
potential
pathway
of
inhaled
fine
particles
to
residents
should
be
considered
for
chat
processing
as
well
as
the
transportation
and
storage
phases.
Figure
2
maps
out
many
of
the
potential
pathways
associated
with
the
lifetime
of
chat­
containing
asphalt.
Missing
from
this
diagram
are
the
effects
on
residents
living
adjacent
to
piles
undergoing
reworking.
From
the
"
Dry
sieving,
washing,
recycling"
box,
there
should
be
a
box
that
goes
directly
to
particle
emission,
follows
an
inhalation
pathway,
and
ends
up
at
a
resident
receptor.
In
addition,
for
particle
emission
from
embankment
or
fill,
these
particles
also
may
follow
an
inhalation
pathway
to
a
resident
receptor.
The
piles
are
collocated
in
residential
areas,
so
activities
such
as
dry
sieving
are
likely
to
mobilize
fine
particles,
and
small
respirable
particles
remain
in
the
atmosphere
long
enough
to
be
transported
to
homes.
Size
fractionated
data
that
I
have
seen
from
the
Harvard
group
show
concentrations
in
the
fine
fractions
can
be
as
high
as
30%
for
Zn
(
300,000
ppm)
and
2%
for
Pb.
Even
though
these
particles
represent
a
small
fraction
of
the
overall
mass
of
the
chat,
they
can
be
mobilized
off­
site
by
windborne
transport.
Given
their
high
metal
concentrations,
even
low
exposures
to
either
airborne
particles
or
soil
onto
which
the
particles
have
landed
may
lead
to
high
metal
exposures.

Another
factor
that
wasn't
considered
is
the
generation
of
fine­
particle
wastes.
If
for
certain
applications
only
a
coarser
chat
fraction
is
required,
a
separation
step
(
washing
or
physical
sieving)
will
generate
fine
chat
as
a
waste
product
to
dispose.
Given
the
relatively
high
concentrations
(
and
potentially
very
different
leachability
relative
to
large
particles),
this
may
4
create
a
larger
problem
to
the
local
environment.
The
human
and
ecological
health
implications
of
fine
chat
disposal
were
not
examined
in
this
assessment.

4.
As
with
any
risk
assessment,
there
are
various
sources
of
uncertainty
associated
with
data
limitations
that
we
believe
are
identified
in
the
report.
Other
than
conducting
model
simulations
or
performing
additional
sampling,
can
you
recommend
alternate
approaches
or
changes
to
our
methodology
that
could
provide
a
more
thorough
characterization
of
those
uncertainties?

Suggested
changes
to
the
methodology
have
been
provided
in
response
to
question
3.
The
site
conceptual
model
should
be
altered
to
include
other
pathways
of
exposure.
Furthermore,
the
uncertainties
of
extrapolating
from
short­
term
laboratory­
based
TCLP
experiments
to
long­
term
fate
should
be
considered.

5.
The
Agency
was
directed
to
establish
criteria
for
the
safe
and
environmentally
protective
use
of
chat
for
cement
or
concrete
projects
and
transportation
construction
projects.
There
were
significant
data
limitations
as
well
as
resource
and
time
constraints
placed
on
the
evaluation.
Does
this
type
of
analysis
lend
technical
support
to
the
nature
of
the
decision
to
establish
criteria
for
the
use
of
chat?
Can
you
propose
alternative
approaches
that
can
be
used
to
support
this
type
of
decision
in
situations
where
there
are
significant
data
or
time
limitations?

Overall,
the
approach
used
in
the
report
seems
reasonable,
given
the
constraints
of
available
data.
However,
there
are
several
areas
where
additional
estimates
or
interpretation
would
be
useful.

Estimating
health
risks
from
particle
inhalation.
In
the
health
screening
criteria,
only
soil
screening
levels
are
included
in
Table
20
as
a
guideline
for
residential
exposure.
Is
there
a
way
that
exposure
from
direct
inhalation
by
residents
of
particles
mobilized
during
chat
reworking
can
be
estimated?
This
type
of
estimate
would
require
total
metal
concentrations
in
small
respirable
particles,
as
well
as
estimated
concentrations
of
respirable
particles
in
the
ambient
air
resulting
from
chat
reworking.
While
the
metal
concentrations
in
wind­
mobilizable
and
respirable
particles
are
available
from
the
work
of
ODEQ
(
2002)
and
from
the
Harvard
group,
the
actual
concentration
of
metals
on
windborne
particles
in
the
air
is
less
straightforward.
Can
realistic
concentrations
be
obtained
from
the
literature
of
other
sites
where
material
is
transported
and
sieved?
Ambient
concentrations
of
metals
in
the
air
during
the
reworking
of
chat
can
be
used
to
estimate
a
dose
of
inhaled
metal
compared
to
acceptable
daily
doses.

Worker
exposure.
The
authors
assert
in
the
Summary
that
the
EPA
determined
that
worker
health
is
sufficiently
protected
by
the
States
and
by
OSHA.
Do
the
authors
feel
their
results
support
the
EPA's
conclusion?
Given
the
recommendation
to
avoid
unencapsulated
chat
uses,
it
seems
special
workplace
precautions
should
be
in
place.
5
Appropriate
uses
of
flowable
fill.
The
report
makes
a
strong
case
that
unencapsulated
uses
of
raw
chat
should
be
avoided,
while
encapsulated
uses
were
found
to
pose
acceptably
low
risk.
While
avoiding
the
use
of
unencapsulated
chat
seems
well­
justified
in
light
of
the
available
data,
there
is
potential
concern
over
the
use
of
chat
in
flowable
fill,
which
is
an
encapsulated
use
and
generally
contains
particles
<
75
µ
m
(
Section
3.2.3).
Given
that
particles
in
this
size
range
were
shown
to
have
up
to
9
times
higher
Pb
concentrations
than
raw
bulk
chat
(
ODEQ
2002),
there
seems
to
be
the
potential
for
much
greater
metal
leaching
from
this
material
than
from
chatbased
asphalt
that
uses
larger
sized
particles.
Furthermore,
data
that
I
have
seen
from
the
Harvard
group
suggest
that
the
metals
contained
in
smaller
sized
particles
have
greater
lability
and
potential
environmental
mobility.
Consequently,
the
results
of
leaching
experiments
on
bulk
particles
may
not
be
representative
of
the
mobility
of
particles
in
smaller
size
fractions.
Before
the
use
of
flowable
fill
that
contains
chat
can
be
deemed
acceptable,
there
should
be
additional
research
to
directly
assess
leaching
of
metals
from
flowable
fill.
In
the
absence
of
such
data,
perhaps
greater
caution
is
warranted.
The
authors
were
not
clear
in
the
conclusions
as
to
whether
the
use
of
flowable
fill
is
an
acceptable
encapsulated
use.

Provisions
for
chain
of
information.
The
authors
describe
the
milling
of
spent
asphalt
and
mention
"
the
recycling
process
involves
removal
and
subsequent
milling
operations
intended
to
produce
the
gradation
properties
of
virgin
materials.
We
assume
that
these
activities
are
subject
to
environmental
standards
for
air
emissions
that
greatly
reduce
or
eliminate
offsite
contamination."
Is
there
any
way
to
notify
workers
before
they
dig
up
a
road
to
recycle
the
asphalt
that
the
asphalt
contains
chat?
Presumably,
precautions
are
always
taken
to
minimize
exposure
during
any
road
rebuilding
operation,
but
perhaps
special
precautions,
especially
to
protect
the
health
of
nearby
residents,
should
be
taken
when
chat­
containing
asphalt
is
to
be
replaced.

Additional
data
for
household
exposure
to
encapsulated
chat
uses.
Another
alternate
approach
to
study
this
issue
is
to
examine
cases
where
chat
has
already
been
used
in
encapsulated
purposes.
There
are
a
number
of
homes
in
the
Tar
Creek
area
that
have
used
chat
in
the
construction
of
their
home
foundation.
Are
there
any
data
on
household
measures
of
Zn,
Pb,
and
Cd
at
these
homes
that
will
inform
us
as
to
the
long
term
integrity
of
metals
in
encapsulated
uses?
Again,
this
type
of
study
would
go
beyond
the
reliance
on
TCLP
tests,
which
represent
only
one
pathway
through
which
metals
in
chat
may
come
off
of
encapsulated
material.