USEPA
2002c
Page
1
of
4
Screening
History
for
the
Part
503
Round
One
and
Two
Proposals
I.
A
Preliminary
Hazard
Identification
Study
was
conducted
to
identify
a
pollutant
candidate
list
for
the
Round
Two
proposal.
An
initial
set
of
candidates
were
composed
of
the
411
pollutants
analyzed
in
the
1988
National
Sewage
Sludge
Survey
(
NSSS).
This
included
every
organic
pollutant
including
pesticides,
dibenzofuran,
dioxin,
and
PCB
analytes
for
which
EPA
had
gas
chromatography
and
mass
spectrometry
standards
(
58
FR
9268­
9269).

Most
of
the
original
411
pollutants
were
eliminated
for
consideration
in
the
Round
Two
rulemaking
due
to
the
following:

°
Ten
pollutants
were
eliminated
because
they
were
regulated
in
the
Round
One
rule
(
i.
e.,
metals).

°
Total
residue
was
eliminated
because
it
is
the
inert
material
left
after
all
the
pollutants
have
been
extracted
from
the
sewage
sludge.

°
Total
kjeldahl
nitrogen
(
i.
e.,
the
sum
of
the
concentrations
of
ammonia
and
organic
nitrogen
compounds)
was
eliminated
because
the
concentrations
of
the
individual
compounds
cannot
be
discerned
and
because
nitrogen
is
already
controlled
through
management
practices
in
Part
503.

°
Dinoseb
(
a
herbicide)
was
eliminated
because
all
U.
S.
uses
have
been
cancelled,
and
the
analysis
of
this
compound
could
not
be
conducted
in
the
1988
NSSS.

(
398
pollutants
remaining)

°
Two
classes
of
pollutants
were
formed
by
aggregating
individual
pollutants.


Seven
PCB
Aroclor
mixtures
were
combined
into
one
category
(
6
pollutants
eliminated).


Twenty­
five
dioxins/
dibenzofurans
were
combined
by
multiplying
each
congener's
concentration
by
its
corresponding
toxicity
equivalency
factor
and
adding
the
resultant
values
over
all
congeners
(
24
pollutants
eliminated).

(
368
pollutants
remaining)

°
254
pollutants
were
eliminated
from
further
consideration
because
they
had
a
frequency
detection
of
less
than
one
percent
in
sewage
sludge
sampled
in
the
1988
NSSS.

(
114
pollutants
remaining)
USEPA
2002c
Page
2
of
4
°
Of
the
remaining
114
pollutants,
69
were
eliminated
from
further
consideration
because
they
were
detected
less
than
ten
percent
of
the
time
and
the
results
of
a
toxicity
analysis
indicated
that
the
pollutants
did
not
have
the
potential
to
adversely
affect
human
health
or
the
environment.


Either
an
oral
risk
reference
dose
(
RfD)
or
an
oral
cancer
potency
value
(
Q*)
was
needed
to
calculate
risk
to
human
health,
and
a
risk
quotient
(
RQ)
was
needed
to
calculate
ecological
risk.
Of
the
69
pollutants
eliminated,
49
had
at
least
one
of
these
estimates
of
toxicity.
The
remaining
20
pollutants
were
excluded
because
there
was
not
enough
information
currently
available
to
conduct
a
toxicity
assessment.
As
a
result,
they
were
added
to
Table
1
below.


Six
of
49
pollutants
(
i.
e.,
aldrin,
dieldrin,
DDT,
DDE,
trichloroethene,
and
benzo(
a)
pyrene)
had
already
been
assessed
in
the
Round
One
rule
and
were
eliminated
from
further
consideration.
As
a
result,
EPA
estimated
risk
for
43
of
the
69
pollutants
eliminated
in
this
screening
phase.


For
all
but
one
of
the
43
pollutants,
the
ratio
of
exposure
to
RfD
was
below
one;
the
cancer
risk
was
below
one
in
10,000;
and
the
RQ
was
below
one.
The
ratio
of
exposure
to
RfD
was
five
for
2­
picoline.
However,
EPA
chose
not
to
evaluate
it
further
because
it
was
only
detected
one
percent
of
the
time
in
the
1988
NSSS.
Because
the
RfD
for
2­
picoline
was
greater
than
one,
it
was
added
to
Table
1
below.

(
45
pollutants
remaining)

°
Of
the
45
pollutants,
15
had
no
human
or
ecological
toxicity
data
available.
As
a
result,
they
were
added
to
Table
1
below.

(
30
pollutants
remaining)

°
Asbestos
was
raised
as
a
possible
candidate
during
the
public
comment
period
for
the
Round
One
rule.
Even
though
asbestos
was
not
one
of
the
411
pollutants
analyzed
in
the
1988
NSSS,
it
is
known
to
be
present
in
sewage
sludge.
As
a
result,
asbestos
was
included
as
a
potential
Round
Two
pollutant
candidate.

(
31
pollutants
remaining)

Summary:
In
May
1993,
as
a
result
of
the
Preliminary
Hazard
Identification
Study,
EPA
reported
to
the
Court
that
it
would
include
31
pollutants
on
its
preliminary
candidate
list
for
potential
regulation
in
Round
Two.

II.
A
Comprehensive
Hazard
Identification
Study
was
conducted
on
the
31
pollutant
USEPA
2002c
Page
3
of
4
candidates
identified
in
the
preliminary
study
to
determine
the
final
list
for
Round
Two.

°
Based
on
the
results
of
the
assessment,
12
of
the
31
pollutant
candidates
had
critical
pathways
for
land
application,
and
5
of
the
12
pollutant
candidates
also
had
critical
pathways
for
surface
disposal.
There
were
no
pollutants
that
had
critical
pathways
for
incineration.
The
remaining
19
pollutants
did
not
have
critical
pathways
for
land
application,
surface
disposal,
or
incineration
and,
as
a
result,
were
eliminated
from
further
consideration.

(
12
pollutants
remaining)

°
It
was
concluded
that
10
inorganic
pollutants
with
critical
pathways
for
land
application
and
surface
disposal
should
not
be
included
on
the
final
list
of
pollutants
for
Round
Two.
The
justifications
were
made
on
a
pollutant
by
pollutant
basis.
Of
these
10
inorganic
pollutants,
eight
were
eliminated
due
to
a
lack
of
data
and
were
added
to
Table
1
below.

(
2
pollutants
remaining)

Summary:
In
November
1995,
as
a
result
of
the
Comprehensive
Hazard
Identification
Study,
EPA
reported
to
the
Court
that
it
would
consider
proposing
Round
Two
regulation
for
two
pollutants:
dioxins/
dibenzofurans
and
coplanar
PCBs.
USEPA
2002c
Page
4
of
4
Table
1.
44
Candidate
Pollutants
Identified
for
Further
Research
2­
Picoline
Cobalt
Docosane,
n
­
*
Octadecane,
n
­
*
Benzo(
B)
fluoranthene
Cymene,
p
­
*
BHC,
beta
­
Benzo(
K)
fluoranthene
Chrysene
Hexanone,
2
­
*
Benz(
A)
anthracene
Nitrofen
(
TOK)
BHC,
alpha
­
Diepoxybutane,
1,2:
3,4
­
*
Pentanone,
4­
methyl­
2­
*
Phenanthrene
Phosphoric
acid,
tri­
o­
tolyl
ester
*
Terpineol,
alpha
­
*
Tetraethylpyrophosphate
*
Dibenzofuran
*
Methylnaphthalene,
2
­
Calcium
*
Decane,
n
­
1
*
Dodecane,
n
­
*
Eicosane,
n
­
*
Hexacosane,
n
­
*
Hexadecane,
n
­
*
Hexanoic
acid
*
Iron
Magnesium
*
Octacosane,
n
­
*
Sodium
*
Tetracosane,
n
­
*
Tetradecane,
n
­
*
Triacontane,
n
­
*
Yttrium
Aluminum
Antimony
Barium
Boron
Fluoride
Manganese
Tin
Titanium

Note:
Subsequently,
23
of
the
44
candidate
pollutants
identified
for
further
research
are
considered
to
be
non­
toxic
or
non­
persistent
in
the
terrestrial
environment
at
the
concentrations
found
in
sewage
sludge
and
are,
therefore,
being
eliminated
from
further
consideration
for
potential
addition
to
the
Part
503
rule.
The
remaining
21
candidate
pollutants
are
being
considered
for
further
research.
