Friday,

July
18,
2003
Part
V
Environmental
Protection
Agency
Announcement
of
Regulatory
Determinations
for
Priority
Contaminants
on
the
Drinking
Water
Contaminant
Candidate
List;
Notice
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No.
138
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Friday,
July
18,
2003
/
Notices
ENVIRONMENTAL
PROTECTION
AGENCY
[
FRL
 
7529
 
2]

Announcement
of
Regulatory
Determinations
for
Priority
Contaminants
on
the
Drinking
Water
Contaminant
Candidate
List
AGENCY:
Environmental
Protection
Agency.
ACTION:
Notice.

SUMMARY:
The
Safe
Drinking
Water
Act
(
SDWA),
as
amended
in
1996,
directs
the
United
States
Environmental
Protection
Agency
(
EPA)
to
publish
a
list
of
contaminants
(
referred
to
as
the
Contaminant
Candidate
List,
or
CCL)
to
assist
in
priority­
setting
efforts
for
the
Agency's
drinking
water
program.
SDWA
also
directs
the
Agency
to
select
five
or
more
contaminants
every
five
years
from
the
current
CCL
and
determine
whether
or
not
to
regulate
these
contaminants
with
a
National
Primary
Drinking
Water
Regulation
(
NPDWR).
On
June
3,
2002,
EPA
published
preliminary
regulatory
determinations
for
nine
contaminants
together
with
the
determination
process,
rationale,
and
supporting
technical
information
for
each
contaminant
to
seek
comment
from
the
public
(
67
FR
38222).
The
nine
contaminants
include
three
inorganic
compounds
(
IOCs)
(
manganese,
sodium,
and
sulfate);
three
synthetic
organic
compounds
(
SOCs)
(
aldrin,
dieldrin,
and
metribuzin);
two
volatile
organic
compounds
(
VOCs)
(
hexachlorobutadiene
and
naphthalene);
and
one
microbial
contaminant,
Acanthamoeba.
EPA's
preliminary
determination
was
that
no
regulatory
action
was
appropriate
for
any
of
the
nine
contaminants.
EPA
received
15
comments
from
individuals
or
organizations
on
the
preliminary
regulatory
determinations
for
the
nine
contaminants.
The
Agency
has
reviewed
these
comments
and,
after
careful
consideration,
decided
that
no
regulatory
action
is
appropriate,
at
this
time,
for
the
nine
CCL
contaminants
published
in
the
June
2002
notice.
Regulation
of
the
nine
contaminants
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
public
water
systems
(
PWSs).
Today's
action
describes
the
statutory
requirements
for
the
CCL,
the
analysis
EPA
used
to
make
the
regulatory
determinations,
a
summary
of
relevant
public
comments
with
the
Agency's
responses,
a
summary
of
the
nine
CCL
contaminants,
and
the
Agency's
findings
for
each
contaminant.
ADDRESSES:
The
official
public
docket
for
this
action
is
located
at
EPA's
West
Building,
Room
B
 
102,
1301
Constitution
Avenue,
NW.,
Washington,
DC.
FOR
FURTHER
INFORMATION
CONTACT:
For
copies
of,
and
general
information
about
this
document
or
information
about
the
nine
contaminants
discussed
in
this
action,
contact
the
Safe
Drinking
Water
Hotline.
Callers
within
the
United
States
may
reach
the
Hotline
at
(
800)
426
 
4791
or
its
local
number
(
703)
412
 
3330.
The
Hotline
is
open
Monday
through
Friday,
excluding
Federal
holidays,
from
9
a.
m.
to
5:
30
p.
m.,
Eastern
Time.
For
technical
inquiries
contact:
Thomas
Carpenter
(
202)
564
 
4885,
e­
mail:
carpenter.
thomas@
epa.
gov
or
Harriet
Colbert,
(
202)
564
 
4698,
e­
mail:
colbert.
harriet@
epa.
gov.

SUPPLEMENTARY
INFORMATION
I.
General
Information
A.
Does
This
Notice
Apply
to
My
Public
Water
System?
Today's
action
does
not
impose
any
requirements
on
anyone.
Instead,
it
notifies
interested
parties
of
EPA's
responses
to
comments
received
on
EPA's
preliminary
determination
and
of
EPA's
final
determination
not
to
regulate
nine
CCL
contaminants.

B.
How
Can
I
Get
Copies
of
Related
Information?
1.
Docket.
EPA
has
established
an
official
public
docket
for
this
action
under
Docket
ID
No.
OW
 
2002
 
0021.
The
official
public
docket
is
the
collection
of
materials
that
is
available
for
public
viewing
at
the
Water
Docket
in
the
EPA
Docket
Center,
(
EPA/
DC)
EPA
West,
Room
B102,
1301
Constitution
Avenue,
NW.,
Washington,
DC.
The
EPA
Docket
Center
Public
Reading
Room
is
open
from
8:
30
a.
m.
to
4:
30
p.
m.,
Monday
through
Friday,
excluding
legal
holidays.
The
telephone
number
for
the
Public
Reading
Room
is
(
202)
566
 
1744,
and
the
telephone
number
for
the
Water
Docket
is
(
202)
566
 
2426.
2.
Electronic
Access.
You
may
access
this
Federal
Register
document
electronically
through
the
EPA
Internet
under
the
``
Federal
Register''
listings
at
http://
www.
epa.
gov/
fedrgstr/.
An
electronic
version
of
the
public
docket
is
available
through
EPA's
electronic
public
docket
and
comment
system,
EPA
Dockets.
You
may
use
EPA
Dockets
at
http://
www.
epa.
gov/
edocket/
to
view
public
comments,
access
the
index
listing
of
the
contents
of
the
official
public
docket,
and
to
access
those
documents
in
the
public
docket
that
are
available
electronically.
Although
not
all
docket
materials
may
be
available
electronically,
you
may
still
access
any
of
the
publicly
available
docket
materials
through
the
docket
facility
identified
in
section
I.
B.
1.
Once
in
the
system,
select
``
search,''
then
key
in
the
appropriate
docket
identification
number.

Abbreviations
and
Acronyms
Used
in
This
Action
ATSDR
Agency
for
Toxic
Substances
and
Disease
Registry
AWQC
Ambient
Water
Quality
Criteria
CASRN
Chemical
Abstract
Services
Registry
Number
CCL
Contaminant
Candidate
List
CWS
Community
Water
Supply
EPA
U.
S.
Environmental
Protection
Agency
FDA
U.
S.
Food
and
Drug
Administration
FR
Federal
Register
g
gram
HRL
Health
reference
level
IOC
Inorganic
compound
kg
Kilogram
L
Liter
MCL
Maximum
contaminant
level
MCLG
Maximum
contaminant
level
goal
mg
milligram
MTBE
Methyl­
t­
butyl
ether
NDWAC
National
Drinking
Water
Advisory
Council
NIRS
National
Inorganic
and
Radionuclide
Survey
NPDWR
National
Primary
Drinking
Water
Regulation
NRC
National
Research
Council
OPP
Office
of
Pesticides
Program
ORD
Office
of
Research
and
Development
PWS
Public
Water
System
RSC
Relative
Source
Contribution
SAB
Science
Advisory
Board
SDWA
Safe
Drinking
Water
Act
SOC
Synthetic
organic
compound
TRI
Toxic
Release
Inventory
UCM
Unregulated
Contaminant
Monitoring
USEPA
United
States
Environmental
Protection
Agency
USGS
United
States
Geological
Survey
VOC
Volatile
organic
compound
II.
Background
A.
What
Is
the
Statutory
Requirement
for
the
Contaminant
Candidate
List?

SDWA,
as
amended
in
1996,
directs
EPA
to
publish
a
list
of
contaminants
(
referred
to
as
the
Contaminant
Candidate
List,
or
CCL)
to
assist
the
Agency
in
priority­
setting
efforts.
The
CCL
is
a
list
of
contaminants
which
are
not
subject
to
any
proposed
or
promulgated
NPDWRs,
are
known
or
anticipated
to
occur
in
PWSs,
and
may
require
regulation
under
SDWA.

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18,
2003
/
Notices
The
first
CCL
was
developed
with
considerable
input
from
the
scientific
community
and
stakeholders.
EPA
published
a
draft
CCL
requesting
public
comment
on
October
6,
1997
(
62
FR
52193,
USEPA
1997).
The
first
final
CCL
was
published
on
March
2,
1998
(
63
FR
10273,
USEPA
1998).
The
SDWA
requires
that
a
new
CCL
be
published
every
five
years.
EPA
is
currently
preparing
the
next
CCL.
The
March
1998
CCL
contained
60
contaminants,
including
50
chemicals
or
chemical
groups
and
10
microbiological
contaminants
or
microbial
groups.
Many
of
these
contaminants
lacked
some
of
the
information
necessary
to
support
a
regulatory
determination
and
were
identified
in
the
March
1998
CCL
notice
(
USEPA
1998)
as
having
data
needs.
The
60
CCL
contaminants
were
divided
into
categories
to
represent
research
and
data
needs
associated
with
each
contaminant.
The
categories
were:
(
1)
Regulatory
determination
priorities;
(
2)
health
effects
research
priorities;
(
3)
treatment
research
priorities;
(
4)
analytical
methods
research
priorities;
and
(
5)
occurrence
priorities.
In
1998,
20
of
the
60
contaminants
were
classified
as
regulatory
determination
priorities
because
EPA
believed
that,
at
that
time,
there
was
sufficient
data
for
these
contaminants
to
evaluate
both
exposure
and
risk
to
public
health
and
to
support
a
determination
of
whether
or
not
to
proceed
to
promulgation
of
a
NPDWR.
Since
the
March
1998
CCL,
EPA
found
that
there
was
insufficient
information,
in
the
Agency's
judgement,
to
support
a
regulatory
determination
for
12
of
the
20
priority
contaminants.
In
addition,
the
CCL­
contaminant,
sodium,
was
reclassified
and
added
to
the
list
of
regulatory
determination
priorities
as
a
means
of
reassessing
the
current
guidance
level
for
sodium.
Thus,
EPA
is
now
presenting
regulatory
determinations
for
nine
priority
contaminants
that
have
sufficient
information
to
support
a
regulatory
determination
at
this
time.
The
Agency
however,
continues
to
conduct
research
and/
or
to
collect
occurrence
information
on
the
remaining
51
CCL
contaminants.
EPA
has
been
aggressively
conducting
research
to
fill
in
the
data
gaps
and
recognizes
that
stakeholders
may
have
a
particular
interest
in
the
timing
of
future
regulatory
determinations
for
other
contaminants
on
the
CCL.
Stakeholders
may
be
concerned
that
regulatory
determinations
for
such
contaminants
should
not
necessarily
wait
until
the
end
of
the
next
regulatory
determination
cycle.
In
this
regard,
it
is
important
to
recognize
that
the
Agency
is
not
precluded
from
monitoring,
conducting
research,
developing
guidance,
or
regulating
contaminants
not
included
on
the
CCL
as
necessary
and
appropriate
(
see
SDWA
sections
1412(
b)(
1)(
B)(
ii)(
III)
and
1412(
b)(
1)(
F)),
or
from
taking
action
on
CCL
contaminants
when
information
becomes
available.
Thus,
some
regulatory
determinations
may
be
made
before
the
end
of
the
next
regulatory
determination
cycle
(
i.
e.,
August
2006).

B.
What
Contaminants
Did
EPA
Consider
for
Regulation?
EPA
published
preliminary
regulatory
determinations
in
the
June
3,
2002,
edition
of
the
Federal
Register
(
67
FR
38222,
USEPA
2002a)
for
nine
priority
contaminants
that
have
sufficient
information
to
support
a
regulatory
determination
at
this
time.
The
nine
contaminants
include
three
IOCs
(
manganese,
sodium,
and
sulfate);
three
SOCs
(
aldrin,
dieldrin,
and
metribuzin);
two
VOCs
(
hexachlorobutadiene
and
naphthalene);
and
one
microbial
contaminant,
Acanthamoeba.
Information
for
each
of
the
nine
CCL
contaminants
is
available
in
the
EPA
Fact
Sheet
(
USEPA
2002b),
in
the
Health
Effects
Support
Documents
or
Drinking
Water
Advisories
for
each
of
the
nine
CCL
contaminants
(
2003a
 
h),
and
in
the
regulatory
determination
support
documents
(
USEPA
2001a
 
g).
This
information
is
available
at
the
Water
Docket
(
No.
OW
 
2002
 
021)
and
is
also
available
on
EPA's
Safe
Drinking
Water
Regulatory
Determination
website
at
http://
www.
epa.
gov/
safewater/
ccl/
cclregdetermine.
html.
Brief
descriptions
of
each
of
the
nine
CCL
contaminants
considered
for
regulatory
determinations
are
included
in
section
V
of
this
notice.

III.
What
Analyses
Did
EPA
Use
To
Make
the
Regulatory
Determinations?
The
precepts
for
guiding
EPA
in
making
regulatory
determinations
for
a
drinking
water
contaminant
are
included
in
Section
1412(
b)(
1)(
A)
of
SDWA.
This
section
of
SDWA
requires
EPA
to
consider
the
following
three
evaluation
criteria
prior
to
making
a
regulatory
decision:
(
1)
Potential
adverse
health
effects
from
the
contaminant;
(
2)
occurrence
of
the
contaminant
in
PWSs
with
a
frequency
and
at
levels
of
public
health
concern;
and
(
3)
whether
regulation
of
the
contaminant
would
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
EPA
developed
a
comprehensive
approach
for
making
regulatory
determinations
with
significant
expert
input
and
recommendations
suggested
by
the
National
Research
Council
(
NRC),
National
Drinking
Water
Advisory
Council
(
NDWAC),
and
stakeholders.
The
regulatory
determination
approach
is
largely
based
on
the
NDWAC
recommendations.
For
each
of
the
nine
contaminants,
EPA
evaluated
the
best
available
peer
reviewed
data
on
health
effects,
and
approximately
seven
million
analytical
data
points
on
contaminant
occurrence.
For
those
contaminants
with
adequate
monitoring
methods,
as
well
as
health
effects
and
occurrence
data,
EPA
applied
an
approach
in
making
regulatory
determinations
that
followed
the
NDWAC
recommendations
and
complies
with
the
SDWA
requirements
under
Section
1412(
b)(
1)(
A).
In
June
2002,
EPA
consulted
with
the
Science
Advisory
Board
(
SAB)
Drinking
Water
Committee
and
requested
its
review
and
comment
on
whether
the
protocol
EPA
developed,
based
on
the
NDWAC
recommendations,
was
consistently
applied
and
appropriately
documented.
The
SAB
provided
verbal
feedback
regarding
the
use
of
the
NRC
and
NDWAC
recommendations
in
EPA's
decision
criteria
for
making
its
regulatory
determinations,
as
well
as
its
interest
in
remaining
involved
in
future
regulatory
determinations.
SAB
recommended
that
the
Agency
provide
a
transparent
and
clear
explanation
of
the
process
for
making
regulatory
determinations.
In
today's
announcement
and
in
the
documentation
supporting
this
announcement,
the
Agency
has
taken
the
SAB
recommendation
into
consideration
in
explaining
the
evaluation
process
used
to
make
today's
regulatory
determinations.
EPA
characterized
the
human
health
effects
that
may
result
from
exposure
to
a
contaminant
found
in
drinking
water.
Based
on
this
characterization,
EPA
estimated
a
health
reference
level
(
HRL)
or
benchmark
value
for
each
contaminant.
EPA
has
prepared
Health
Effects
Support
Documents
or
Drinking
Water
Advisories
(
USEPA
2002c
and
2003a
 
g)
for
each
contaminant,
which
are
available
at
the
EPA
Water
Docket
and
on­
line
at
http://
www.
epa.
gov/
edocket/.
The
support
documents
address
the
following:
Exposure
from
drinking
water
and
other
media;
toxicokinetics;
hazard
identification;
dose­
response
assessment;
and
an
overall
characterization
of
risk
from
drinking
water.
Using
the
Agency's
Unregulated
Contaminant
Monitoring
(
UCM)
program
data
and
National
Inorganic
and
Radionuclide
Survey
(
NIRS)
data,
EPA
estimated
the
number
of
PWSs
and
the
population
served
by
the
PWSs
at
the
benchmark
values,
and
the
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18,
2003
/
Notices
geographic
distribution,
using
a
large
amount
of
State
occurrence
data
that
are
generally
indicative
of
national
occurrence.
The
UCM
data
form
part
of
the
Agency's
basis
for
its
estimates
of
national
occurrence
since
these
data
provide
occurrence
information
for
several
unregulated
contaminants.
The
NIRS
data
provide
a
statistically
representative
sample
of
the
national
occurrence
of
many
other
unregulated
and
regulated
inorganic
contaminants
in
ground
water
community
water
supplies
(
CWSs).
EPA
also
employed
other
State
drinking
water
data,
use
and
environmental
release
information
(
e.
g.,
EPA's
Toxic
Release
Inventory
(
TRI),
academic
and
private
sector
publications),
as
well
as
ambient
water
quality
data
(
i.
e.,
source
water
existing
in
surface
waters
and
aquifers
before
extraction
and
treatment
as
drinking
water),
to
augment
the
UCM
drinking
water
data
and
to
evaluate
the
likelihood
of
contaminant
occurrence.
EPA
included,
when
available,
data
from
the
U.
S.
Geological
Survey's
(
USGS)
National
Water
Quality
Assessment
program.
A
detailed
discussion
of
the
data
collected
and
analyses
for
each
contaminant
can
be
found
in
the
respective
regulatory
determination
support
document.
The
regulatory
determination
support
documents
(
USEPA
2001a
 
g)
are
available
in
the
EPA
Water
Docket.
The
underlying
data
and
analysis
supporting
the
findings
used
by
the
Agency
to
make
the
regulatory
determinations
are
summarized
in
the
June
2002
notice
(
USEPA
2002a).

IV.
Summary
of
Public
Comments
and
the
Agency's
Responses
on
the
CCL
Regulatory
Determination
Process
The
comment
period
on
the
June
3,
2002,
notice
ended
on
August
2,
2002.
EPA
received
15
comments
on
the
preliminary
regulatory
determinations
for
the
nine
CCL
contaminants
published
by
EPA
in
the
June
2002
notice
(
USEPA
2002a).
Four
comments
were
received
from
water
systems
and
related
associations,
seven
from
industry
groups,
two
from
environmental
advocacy
groups,
one
from
a
State
agency
and
one
from
a
State­
related
association.
Although
most
commenters
generally
approved
of
EPA's
determination
not
to
regulate
any
new
contaminants
at
this
time,
some
commenters
expressed
concerns
about
the
process
associated
with
EPA's
regulatory
determinations
for
these
nine
contaminants,
as
well
as
with
CCL
activities
not
specifically
related
to
the
preliminary
determinations.
A
majority
of
the
comments
were
focused
on
five
over­
arching
topic
areas:
1.
Some
commenters
expressed
concern
over
the
transparency
of
the
CCL
decision­
making
process.
2.
Several
industry
groups
expressed
a
concern
that
the
health
effects
assessments
were
too
conservative.
3.
Several
commenters
expressed
concern
with
EPA's
progress
in
filling
research
gaps
related
to
the
CCL
and
encouraged
EPA
to
publicly
track
research
needs
and
progress
on
remaining
CCL
contaminants.
4.
The
majority
of
commenters
generally
approved
of
EPA's
determination
not
to
regulate
any
new
contaminants
at
this
time.
However,
one
commenter
questioned
the
appropriateness
of
EPA's
decisions
not
to
regulate
any
of
the
nine
priority
contaminants.
5.
Several
comments
were
received
regarding
contaminants
on
the
CCL
for
which
draft
regulatory
determinations
were
not
included
in
the
June
2002
notice,
including
perchlorate
and
methyl­
t­
butyl
ether
(
MTBE).
A
complete
copy
of
the
public
comments
and
the
Agency's
responses
are
included
in
the
Docket
for
today's
action.
The
remainder
of
this
section
discusses
the
five
key
topic
areas
identified
by
commenters
in
response
to
the
June
2002
CCL
regulatory
determination
notice
(
USEPA
2002a).

1.
Lack
of
Transparency
of
Regulatory
Determination
Approach
Comment
Summary:
Several
commenters
expressed
a
concern
about
the
``
lack
of
transparency''
in
the
regulatory
determination
approach
used
by
the
Agency
for
the
June
2002
notice.
Most
of
those
commenters
suggested
that
EPA
did
not
provide
an
adequate
explanation
for
the
reduction
in
the
number
of
the
priority
contaminants
from
twenty
to
nine
since
the
publication
of
the
first
CCL
in
March
1998
(
USEPA
1998).
These
commenters
suggested
that
the
Agency
needs
to
provide
better
justification
regarding
the
reasons
for
excluding
the
twelve
contaminants
listed
in
the
March
1998
CCL
from
the
regulatory
determination
process.
Several
commenters
suggested
that
this
regulatory
determination
process
approach
does
not
provide
for
enough
participation
from
outside
groups
for
the
development
of
non­
regulatory
strategies.
These
commenters
suggested
that
the
Agency
should
allow
for
more
meaningful
public
involvement
in
the
regulatory
determination
process.
One
commenter
stated
that,
given
the
Agency's
analysis
of
occurrence
and
health
effects
data
over
several
years,
the
60­
day
comment
period
was
not
adequate
to
allow
``
detailed
analysis
by
interested
stakeholders.''
Other
commenters,
however,
observed
that
the
CCL
regulatory
determination
approach
taken
by
EPA
was
``
reliably
consistent''
with
the
basic
charge
of
the
SDWA
and
the
NDWAC
workgroup
recommendations.
Several
commenters
noted
that,
by
EPA
following
the
protocol
recommended
by
the
NDWAC
Work
Group,
stakeholders
were
assured
that
the
Agency
used
the
``
bestavailable
peer­
reviewed
science''
in
these
determinations.
Agency
Response:
EPA
developed
a
consistent
regulatory
determination
approach
for
evaluating
CCL
contaminants
that
followed
NDWAC's
recommended
protocol
for
health
effects
and
occurrence
analysis.
The
regulatory
determination
approach
for
each
contaminant
on
the
list
included
an
evaluation
of
the
adequacy
of
current
analytical
and
treatment
methods,
the
best
available
peer­
reviewed
data
on
health
effects,
and
an
occurrence
data
set
of
about
seven
million
contaminant
occurrence
data
points.
By
using
this
approach,
EPA
determined
that,
at
the
time
of
the
June
2002
notice
(
USEPA
2002a)
of
preliminary
regulatory
determinations
there
was
not
sufficient
information
to
support
a
regulatory
determination
on
twelve
of
the
twenty
priority
contaminants.
As
noted
previously,
the
CCL­
contaminant,
sodium,
was
moved
to
the
list
of
regulatory
determination
priorities
to
allow
an
update
of
the
Agency's
position
on
the
issue
of
sodium
in
drinking
water.
The
NDWAC,
which
is
comprised
of
representatives
from
the
general
public,
State
and
local
agencies,
and
private
groups
concerned
with
drinking
water
safety,
was
convened
to
provide
input
during
the
regulatory
determination
process.
Throughout
the
regulatory
determination
process,
EPA's
approach
has
been
to
maintain
a
strong
partnership
with
stakeholders
and
involve
them
to
the
maximum
extent
possible,
thereby
helping
to
ensure
that
stakeholders
understand
the
regulatory
determination
process
and
provide
valuable
input.
The
Agency
agrees
that
a
meaningful
opportunity
for
discussions
with
stakeholders
is
an
important
component
of
the
CCL
Regulatory
Determination
process.
The
Agency
utilized
a
variety
of
mechanisms
to
involve
stakeholders
in
the
process.
These
included
two
broad­
based
stakeholder
meetings,
one
in
November
1999
and
one
in
July
2002.
Members
of
the
public
also
were
invited
to
attend
the
three
sessions
of
the
NDWAC
Work
Group
in
the
Spring/

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Summer
of
2000,
which
focused
on
protocol
recommendations
to
the
Agency.
In
addition,
EPA
representatives
delivered
presentations
at
a
variety
of
meetings
held
by
other
organizations.
Moreover,
EPA
did
ask
for
and
considered
comments
made
on
the
sodium
and
sulfate
Drinking
Water
Advisories
during
the
comment
period
on
the
June
2002
notice
(
USEPA
2002a).
The
Agency
believes
the
60­
day
public
comment
period
for
the
June
2002
notice
(
USEPA
2002a)
was
sufficient.
The
Agency
took
steps
to
facilitate
public
review
of
its
preliminary
decisions,
as
well
as
supporting
documentation.
In
addition
to
the
July
2002
stakeholder
meeting,
these
steps
included
making
key
materials
available
on
the
Agency's
website
and
providing
hard
copies
of
materials
upon
request.

2.
Health
Effects
Assessments
Comment
Summary:
Some
commenters
suggested
that
EPA's
analysis
of
adverse
health
effects
and
calculation
of
the
HRLs
were
too
conservative.
On
the
other
hand,
one
commenter
questioned
how
the
Agency's
analysis
underlying
the
regulatory
determination
approach
incorporated
appropriate
safety
factors
and
exposure
assessments
relative
to
children's
health
concerns.
Commenters
recommended
that
EPA
use
the
revised
Office
of
Water
methodology
for
deriving
ambient
water
quality
criteria
(
AWQC),
(
USEPA
2000),
in
an
effort
to
protect
human
health
in
the
final
health
effects
support
documents.
According
to
the
comments,
this
revised
methodology
establishes
five
different
consumption
rates
and
body
weight
classifications
as
a
means
to
make
the
human
health
exposure
assessments.
One
commenter
specified
that
EPA
needs
to
use
more
accurate
consumption
data
for
sodium
rather
than
simply
incorporating
U.
S.
Food
and
Drug
Administration
(
FDA)
assertions.
Agency
Response:
EPA
believes
it
is
appropriate
to
use
a
conservative
approach
to
assessing
the
health
effects
of
an
unregulated
contaminant
in
the
context
of
a
determination
of
whether
it
should
be
considered
for
NPDWR
regulation.
In
order
to
determine
whether
to
propose
an
NPDWR
for
an
unregulated
contaminant,
SDWA
requires
EPA
to
determine
whether
the
contaminant
``
may
have
an
adverse
effect
on
the
health
of
the
persons,''
Section
1412(
b)(
1)(
A)(
i),
which
is
a
very
broad
criterion.
As
a
result,
EPA
believes
that
a
conservative
health
effects
analysis
is
appropriate.
The
HRL
used
by
EPA
in
these
determinations
is
a
conservative
healthbased
value
and
is
different
depending
on
whether
a
contaminant
is
considered
a
carcinogen
or
a
noncarcinogen.
For
carcinogens,
a
10
 
6
risk
was
chosen
as
the
HRL
since
the
maximum
contaminant
level
goal
(
MCLG)
for
such
contaminants
will
generally
be
zero.
For
noncarcinogens,
the
reference
dose
and
a
20
percent
relative
source
contribution
(
RSC)
factor
was
used
in
conjunction
with
a
70
kilogram
(
kg)
adult
body
weight
and
a
2
liter
(
L)
water
intake
for
the
HRL
calculation.
EPA
uses
these
standard
regulatory
assumptions
for
determining
the
MCLG
of
a
noncarcinogen
that
lacks
specific
data
on
the
RSC.
EPA
used
best
available
peer
reviewed
data
and
analyses
in
evaluating
adverse
health
effects.
Accordingly,
EPA
disagrees
with
those
commenters
that
felt
that
EPA
was
too
conservative
in
establishing
the
HRL.
EPA
followed
practices
and
policies
that
are
similar
to
those
used
to
establish
an
NPDWR
and
that
are
consistent
with
the
SDWA
section
1412(
b)(
1)(
A)(
i)
criterion.
If
such
a
conservative
approach
does
not
result
in
EPA
deciding
to
initiate
a
regulatory
process
for
a
contaminant,
the
Agency
may
decide
to
use
a
nonregulatory
approach
in
addressing
the
issue,
such
as
issuing
a
Drinking
Water
Advisory.
Children's
health
issues
were
considered
in
making
regulatory
determinations
for
each
of
the
nine
contaminants
included
in
this
final
notice.
The
details
of
the
individual
assessments
are
included
in
the
Health
Effects
Support
Documents
or
Drinking
Water
Advisories
for
each
contaminant.
These
documents
are
available
for
review
at
the
EPA
Water
Docket
and
online
at
http://
www.
epa.
gov/
edocket/.
The
AWQC
(
USEPA
2000)
methodology
continues
to
recommend
the
use
of
70
kg
for
adult
body
weight
and
2
liters
per
day
for
water
intake
for
risk
calculations.
These
are
the
same
parameters
used
by
EPA
to
derive
an
MCLG.
EPA
believes
that
its
current
methodology,
based
on
adult
exposures,
for
the
derivation
of
MCLGs,
and
for
making
regulatory
determinations
under
SDWA
section
1412,
remains
generally
appropriate.
EPA
has
not
yet
determined
a
protocol
for
making
a
regulatory
determination
for
a
chemical
for
which
an
infant's
or
a
particular
childhood
age
grouping's
body
weight
and
drinking
water
intake
would
be
the
basis
of
a
regulatory
action.
A
decision
for
such
a
contaminant
would
be
made
on
the
basis
of
the
toxicity
and
exposure
data,
and
could
utilize
the
age
groupings
and
body
weight
information
from
the
AWQC
human
health
methodology
if
it
were
appropriate.
EPA
did
not
use
FDA's
sodium
consumption
data
of
4
to
6
grams/
day
(
g/
day)
in
establishing
a
benchmark
value
for
sodium.
EPA
decided
to
use
a
benchmark
value
for
sodium
instead
of
an
HRL
because
sodium
lacks
suitable
dose­
response
data
and
there
is
considerable
controversy
regarding
the
role
of
sodium
in
the
etiology
of
hypertension.
EPA
derived
the
benchmark
value
for
sodium
of
120
mg/
L
in
drinking
water
from
the
National
Institutes
of
Health,
National
Academy
of
Sciences,
American
Heart
Association,
and
the
U.
S.
Department
of
Agriculture
recommended
daily
dietary
intake
of
2.4
g/
day.

3.
EPA
Research
Agenda
Comment
Summary:
Several
commenters
expressed
concern
that,
in
their
view,
there
is
a
lack
of
progress
by
EPA
in
filling
research
gaps
related
to
the
CCL.
In
particular,
commenters
focused
on
high
visibility
contaminants,
such
as
the
microbiological
contaminants,
MTBE,
and
other
``
emerging
contaminants.''
Commenters
also
stressed
the
need
to
establish
a
vehicle
for
publicly
tracking
research
needs
and
progress
made
in
research
areas.
Agency
Response:
Before
EPA
can
determine
whether
to
regulate
contaminants,
additional
data
on
health,
treatment
technologies,
and
analytical
methods,
are
needed
for
contaminants
on
the
Research
Priorities
portion
of
the
CCL,
and
occurrence
data
is
needed
for
contaminants
on
the
Occurrence
Data
Needs
portion
of
the
CCL.
The
remaining
51
CCL
contaminants
for
which
decisions
are
not
being
made
today
do
not
have
sufficient
data
to
support
a
regulatory
determination.
The
Agency
considers
obtaining
this
data
to
be
the
priority
of
its
research
and
occurrence
monitoring
programs.
The
Agency
continues
to
actively
conduct
research
and/
or
to
collect
occurrence
information
on
these
51
CCL
contaminants
and
other
emerging
contaminants.
Because
these
research
issues
are
broader
than
those
that
EPA
can
address
alone,
it
is
anticipated
that
other
entities
will
be
involved
in
conducting
much
of
the
needed
research
to
support
this
process.
For
example,
EPA
already
is
jointly
undertaking
research
efforts,
and
encourages
stakeholders,
through
close
and
regular
consultation,
to
be
partners
in
filling
many
of
the
research
gaps.
The
EPA
continues
to
identify
and
develop
new
collaborations
to
conduct
research
and
gather
the
additional
data
to
characterize
occurrence
and
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health
effects
to
support
future
regulatory
determinations
of
CCL
contaminants.
EPA
is
also
engaged
with
our
stakeholders
in
a
NDWAC
work
group
to
refine
the
CCL
listing
process
to
address
emerging
contaminants
for
future
efforts.
EPA
agrees
with
the
comment
concerning
the
importance
of
establishing
a
vehicle
that
will
allow
stakeholders
to
track
the
status
of
drinking
water
research
projects.
EPA
is
committed
to
providing
a
means
for
stakeholders
to
track
research
needs
and
progress
made
in
research
areas,
and
is
developing
a
web­
based
research
inventory
that
is
expected
to
be
available
to
the
public
in
2003.
This
website
will
serve
as
a
repository
of
information
on
drinking
water
research
projects
currently
funded
or
performed
by
the
EPA.

4.
Criticism
of
Regulatory
Decisions
Made
Comment
Summary:
One
commenter
expressed
concern
that
EPA's
decision
not
to
regulate
any
of
the
nine
priority
contaminants
was
not
appropriate.
A
comment
submitted
and
co­
signed
by
22
environmental
organizations
disagreed
with
the
regulatory
determinations
for
four
contaminants,
hexachlorobutadiene,
manganese,
sodium
and
sulfate.
The
commenters
believe
that
EPA's
monitoring
data
presented
in
the
June
2002
notice
shows
that
over
22,000
people
were
exposed
to
hexachlorobutadiene
at
concentrations
above
the
HRL.
The
commenters
assert
that
although
EPA
says
manganese
has
low
toxicity,
EPA
finds
that
nearly
3%
of
the
population
exceeded
EPA's
HRL.
The
commenters
also
disagreed
with
the
Agency
determination
that
regulation
is
not
warranted
because
food
sources
of
sodium
are
a
more
significant
contribution
to
sodium
in
the
diet
than
drinking
water.
The
commenters
also
assert
that
EPA
should
regulate
sulfate
because
EPA's
monitoring
data
shows
that
millions
of
Americans
are
likely
to
have
sulfate
levels
above
the
HRL
in
their
drinking
water,
which
puts
infants
and
other
subpopulations
at
risk.
Agency
Response:
The
preliminary
regulatory
determinations
on
whether
or
not
to
regulate
the
nine
priority
contaminants
were
based
on
the
three
SDWA
statutory
requirements,
and
the
contaminants
were
evaluated
in
terms
of
national
significance.
EPA's
assessment
of
the
health
effects
and
national
occurrence
were
discussed
in
detail
in
the
June
2002
notice.
EPA
disagrees
that
each
of
the
contaminants
identified
by
the
commenters
should
be
regulated.
The
rationale
supporting
the
regulatory
determination
is
provided
below.
EPA
found
that
hexachlorobutadiene
occurs
in
systems,
but
not
at
a
frequency
or
level
of
public
health
concern.
The
commenter
has
misinterpreted
the
monitoring
data
presented
in
the
June
2002
notice.
The
number
22,736
in
the
notice
refers
to
the
number
of
reporting
PWSs
in
the
monitoring
data
set
and
does
not
reflect
the
number
of
people
exposed
to
hexachlorobutadiene
concentrations
above
the
HRL.
The
June
2002
notice
states
that
0.02%
(
4
out
of
22,736)
reporting
systems
detected
hexachlorobutadiene
above
the
HRL
affecting
0.005%
(
3,350
out
of
the
67
million)
of
the
population
served
by
these
systems
(
67
FR
38235).
Because
of
this
low
frequency,
EPA
believes
it
is
most
appropriate
at
this
time
to
address
occurrence
of
hexachlorobutadiene
at
the
State
level
rather
than
at
the
national
level.
EPA
disagrees
with
the
commenter's
criticism
of
the
decision
not
to
regulate
manganese.
Manganese
is
an
essential
trace
element
needed
for
the
normal
healthy
growth
and
function
of
animals
as
well
as
human
beings.
Therefore,
the
decision
whether
or
not
to
regulate
manganese
needs
to
balance
the
concern
for
the
potential
toxic
effects
from
high
oral
exposure
with
the
concern
for
adverse
effects
from
manganese
deficiency.
In
2001,
the
Institute
of
Medicine
(
IOM)
set
an
adequate
level
for
manganese
at
2.3
mg/
day
for
men
and
1.8
mg/
day
for
woman.
Furthermore,
in
2001,
the
IOM
set
a
tolerable
upper
intake
level
for
manganese
at
11
mg/
day.
While
3%
of
the
population
may
be
exposed
to
manganese
at
levels
above
the
0.30
mg/
L
HRL
for
drinking
water,
this
level
is
well
below
the
IOM
tolerable
level.
For
example,
assuming
a
daily
intake
of
2
liters
of
drinking
water
with
manganese
at
the
HRL
of
0.30
mg/
L,
the
daily
intake
of
manganese
from
drinking
water
at
the
HRL
would
only
expose
a
person
to
0.6
mg/
day.
This
value
is
well
below
IOM's
11
mg/
L
adequate
level
for
manganese
and
represents
only
5.5%
of
IOM's
upper
limit
for
manganese.
Public
drinking
water
accounts
for
a
relatively
small
proportion
of
a
person's
manganese
intake,
even
at
the
HRL.
Therefore,
the
Agency
concludes
that
regulation
of
drinking
water
for
manganese
does
not
provide
a
meaningful
opportunity
to
reduce
the
risk
of
adverse
health
effects.
The
commenter
is
referred
to
the
CCL
Preliminary
Regulatory
Determination
Support
Document
for
Manganese
(
EPA
815
 
R
 
01
 
013)
for
a
more
detailed
discussion
of
this
issue.
EPA
disagrees
with
the
commenter's
criticism
of
the
decision
not
to
regulate
sodium.
Because
sodium
in
drinking
water
is
a
very
small
contributor
to
daily
dietary
intake
and
because
the
levels
at
which
sodium
intake
can
contribute
to
increasing
the
blood
pressure
of
individuals
with
normal
blood
pressures
is
not
clearly
established,
EPA
does
not
believe
that
a
NPDWR
for
sodium
presents
a
meaningful
opportunity
for
public
health
protection
at
this
time.
EPA
disagrees
with
the
commenter's
criticism
of
the
decision
not
to
regulate
sulfate.
EPA
used
current
data
(
Round
2
of
the
UCM
program)
that
indicate
that
about
1.8%
of
the
reporting
systems
serving
approximately
2
million
people
from
a
20­
state
cross
section
of
the
unregulated
contaminant
monitoring
study
exceeded
500
mg/
L.
Although
additional
data
from
six
states
had
very
similar
results,
EPA
found
that
the
weight
of
evidence
suggests
that
the
adverse
health
effect
is
generally
mild,
of
short
duration,
and
generally
occurs
at
concentrations
considerably
greater
than
500
mg/
L,
except
in
very
limited
circumstances
when
contaminants
that
exacerbate
the
effects
of
sulfate
are
also
present
in
the
water.
Therefore,
EPA
has
made
the
determination
not
to
regulate
sulfate
with
a
NPDWR
at
this
time
because
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
public
drinking
water
systems.
However,
EPA
prepared
a
Drinking
Water
Advisory
to
provide
guidance
to
communities
that
may
be
exposed
to
drinking
water
with
high
sulfate
concentrations.
This
advisory
contains
information
of
use
to
sensitive
sub­
populations,
such
as
infants
and
travelers.

5.
Stakeholder's
Highest
Priority
for
Future
Regulatory
Determinations
Comment
Summary:
Commenters
encouraged
EPA
to
be
aggressive
and
consider
an
expedited
regulatory
determination
for
several
CCL
contaminants
including
MTBE
and
perchlorate.
Agency
Response:
For
this
regulatory
determination,
EPA
developed
a
comprehensive
evaluation
approach
based
on
the
recommendations
from
NRC
and
NDWAC.
As
explained
in
the
June
2002
notice
(
USEPA
2002a),
this
evaluation
satisfies
the
three
SDWA
requirements
under
section
1412(
b)(
1)(
A)(
i)
 
(
iii).
For
each
of
the
contaminants,
the
Agency
evaluated
the
adequacy
of
current
analytical
and
treatment
methods,
the
best
available
peer­
reviewed
data
on
health
effects,
and
an
occurrence
data
set
of
approximately
seven
million
analytical
data
points.
At
this
time,
EPA
does
not
believe
adequate
data
exists
in
these
key
areas
to
make
a
regulatory
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Notices
determination
either
for
perchlorate
or
MTBE.
EPA
is
gathering
information
to
fill
the
data
gaps
for
these
contaminants.
With
respect
to
perchlorate,
EPA
is
gathering
national
occurrence
data
on
perchlorate
in
drinking
water
through
the
Unregulated
Contaminant
Monitoring
(
UCM)
Rule.
The
Agency
is
also
completing
a
rigorous
peer
review
of
health
effects
studies
and
is
developing
a
final
toxicity
review
and
risk
characterization.
As
part
of
this
effort,
EPA
has
asked
the
National
Academy
of
Sciences
to
review
science
issues
related
to
the
2002
draft
EPA
risk
assessment
for
perchlorate.
In
addition,
the
Agency
is
funding
research
studies
on
treatability
of
perchlorate
for
PWSs.
Some
of
the
technology
currently
in
use
at
hazardous
waste
sites
is
being
evaluated
for
the
feasibility
of
using
it
in
water
treatment
at
community
water
systems.
At
the
same
time,
EPA
is
seeking
to
improve
the
analytical
method
sensitivity
that
would
allow
concentrations
of
perchlorate
to
be
quantified
at
lower
levels
than
are
presently
possible.
The
Agency
is
moving
concurrently
in
each
of
these
areas
to
meet
data
and
research
needs
as
quickly
as
possible.
When
the
necessary
information
is
collected,
we
plan
to
move
forward
with
a
regulatory
determination.
In
this
regard,
it
should
be
emphasized
that
where
EPA
determines
there
is
sufficient
information
on
this
or
any
other
unregulated
contaminant,
the
Agency
is
prepared
to
act
in
advance
of
the
next
five
year
regulatory
determination
cycle.
Regarding
MTBE,
on­
going
activities
will
provide
the
Agency
with
improved
health
effects
and
occurrence
data.
At
this
time,
EPA
is
preparing
its
revised
risk
assessment
for
MTBE
for
peer
review.
The
Agency
established
the
1997
Drinking
Water
Advisory
for
MTBE
at
20
 
40
micrograms
per
liter
(
µ
g/
L,
or
parts
per
billion,
ppb)
to
avoid
unacceptable
taste
and
odor
and
provide
a
protective
margin
of
exposure
for
adverse
health
effects.
The
20
 
40
ppb
level
was
not
based
on
the
possible
cancer
risks.
As
a
result
of
the
UCM
Rule,
data
from
PWSs
required
to
monitor
for
MTBE
will
be
available
in
the
middle
of
2004.

V.
Summary
of
the
Agency's
Findings
on
the
Nine
CCL
Contaminants
A.
Acanthamoeba
Description:
Acanthamoeba
is
a
freeliving
protozoa
commonly
found
in
water,
soil,
and
air.
Species
of
this
microbe
have
been
isolated
worldwide
from
brackish
and
sea
water,
tap
water,
bottled
water,
airborne
dust,
swimming
pools,
hot
springs,
thermal
effluents
of
power
plants,
ocean
sediments,
vegetables,
and
hot
tubs.
Acanthamoeba
species
have
been
associated
with
human
infections
affecting
the
eye,
lung,
brain,
and
skin.
Acanthamoeba
has
been
recovered
from
the
nose
and
throat
of
humans
with
impaired
respiratory
function
and
from
apparently
healthy
persons,
suggesting
that
the
amoeba
is
commonly
inhaled.
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
Acanthamoeba
with
a
NPDWR
at
this
time,
because
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
the
people
served
by
public
drinking
water
systems
(
PWSs).
As
noted
in
the
June
2002
notice
(
USEPA
2002a),
EPA
has
no
national
monitoring
data
to
indicate
occurrence
of
Acanthamoeba
cysts
in
drinking
water,
and
filtration
practices
commonly
used
to
treat
drinking
water
remove
Acanthamoeba
cysts.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
Acanthamoeba
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
and
in
the
health
effects
support
document
for
Acanthamoeba
(
USEPA
2003h).
EPA
intends
to
release
a
guidance
document
for
Acanthamoeba
that
will
be
directed
mainly
to
contact
lens
wearers
and
will
address
the
risks
of
Acanthamoeba
eye
infection
associated
with
improper
care
of
contact
lenses.

B.
Aldrin
and
Dieldrin
Description:
Aldrin
and
dieldrin
(
Chemical
Abstract
Services
Registry
Number
(
CASRN)
309
 
00
 
2
and
60
 
57
 
1,
respectively)
are
the
common
names
of
two
structurally
similar
insecticides.
They
are
discussed
together
because
aldrin
readily
changes
to
dieldrin
in
the
body
and
in
the
environment,
and
they
cause
similar
adverse
health
effects.
From
1950
 
1970,
aldrin
and
dieldrin
were
popular
pesticides
used
for
crops,
such
as
corn
and
cotton.
Because
of
concerns
about
damage
to
the
environment
and
the
potential
harm
to
human
health,
EPA
banned
most
uses
of
aldrin
and
dieldrin
in
1974,
except
for
the
control
of
termites,
and
banned
all
uses
outright
since
1987.
According
to
the
Agency
for
Toxic
Substances
and
Disease
Registry
(
ATSDR),
aldrin
and
dieldrin
have
not
been
produced
in
the
United
States
since
1974
(
ATSDR
1993).
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
aldrin
or
dieldrin
with
a
NPDWR
at
this
time,
because
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
the
people
served
by
PWSs.
EPA
recognizes
that
aldrin
and
dieldrin
are
probable
human
carcinogens,
but
the
chemicals
have
been
banned
for
most
uses
since
1974,
and
have
a
low
frequency
and
low
level
of
occurrence
in
drinking
water
supplies.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
aldrin
and
dieldrin
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
and
in
the
regulatory
determination
(
USEPA
2001a)
and
health
effects
(
USEPA
2003a)
support
documents
for
aldrin
and
dieldrin.

C.
Hexachlorobutadiene
Description:
Hexachlorobutadiene
(
CASRN
87
 
68
 
3)
is
a
VOC
that
is
relatively
insoluble
in
water
(
solubility
of
2
 
2.55
mg/
L).
Hexachlorobutadiene
is
mainly
used
to
make
rubber
compounds.
It
is
also
used
in
gyroscopes,
as
a
heat
transfer
liquid,
as
a
hydraulic
fluid,
as
a
solvent,
and
to
make
lubricants.
It
has
never
been
manufactured
as
a
commercial
product
in
the
United
States,
however,
it
is
imported
and
significant
quantities
of
the
chemical
are
generated
in
the
United
States
as
a
waste
by­
product
from
the
chlorination
of
hydrocarbons.
Most
exposure
to
hexachlorobutadiene
comes
from
breathing
contaminated
air
in
the
workplace
environment.
People
living
near
hazardous
waste
sites
containing
hexachlorobutadiene
may
be
exposed
to
it
by
breathing
air
or
by
drinking
contaminated
water.
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
hexachlorobutadiene
with
a
NPDWR
at
this
time,
because
it
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Hexachlorobutadiene
occurs
in
PWSs,
but
not
at
a
frequency
or
level
of
public
health
concern.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
hexachlorobutadiene
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
and
in
the
regulatory
determination
(
USEPA
2001b)
and
health
effects
(
USEPA
2003b)
support
documents
for
hexachlorobutadiene.

D.
Manganese
Description:
Manganese
(
CASRN
7439
 
96
 
5)
is
a
naturally
occurring
element
found
at
low
levels
in
soil,
water,
and
food.
It
is
an
essential
trace
element
for
humans
and
all
animal
species.
It
constitutes
approximately
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percent
of
the
earth's
crust,
however,
it
does
not
occur
in
the
environment
in
its
pure
metal
form,
but
is
ubiquitous
as
a
component
of
more
than
100
minerals
including
many
silicates,
carbonates,
sulfides,
oxides,
phosphates,
and
borates
(
ATSDR
2000).
Manganese
is
generally
considered
to
have
low
toxicity
when
ingested
orally.
The
major
source
of
manganese
intake
in
humans
(
with
the
exception
of
possible
occupational
exposure)
is
dietary
ingestion;
manganese
is
a
nutrient
and
is
not
considered
to
be
very
toxic
when
ingested
with
food.
Reports
of
adverse
effects
following
oral
exposure
are
rare.
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
manganese
with
a
NPDWR
at
this
time,
because
it
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Manganese
is
generally
not
considered
to
be
very
toxic
when
ingested
with
the
diet
and
drinking
water
accounts
for
a
relatively
small
proportion
of
manganese
intake.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
manganese
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
and
in
the
regulatory
determination
(
USEPA
2001c)
and
health
effects
(
USEPA
2003c)
support
documents
for
manganese.
EPA
is
developing
a
Drinking
Water
Advisory
for
manganese
to
provide
guidance
to
communities
that
might
be
exposed
to
elevated
concentrations
of
manganese
in
their
drinking
water.

E.
Metribuzin
Description:
Metribuzin
(
CASRN
21087
 
64
 
9)
is
a
pesticide
that
does
not
volatilize
readily,
yet
is
relatively
soluble
in
water.
It
is
relatively
persistent
in
the
environment
and
degrades
primarily
through
exposure
to
sunlight.
Metribuzin
is
used
as
an
herbicide
on
soybeans,
potatoes,
alfalfa,
sugar
cane,
lentils,
asparagus,
tomatoes,
carrots,
peas,
barley,
wheat,
range
grasses,
and
Christmas
trees.
Metribuzin
has
limited
non­
agricultural
utility.
Metribuzin
is
not
classifiable
as
a
human
carcinogen,
but
there
may
be
effects
on
the
liver
and
body
weight
from
chronic
exposure
to
high
doses.
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
metribuzin
with
a
NPDWR
at
this
time,
because
it
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Metribuzin
is
not
known
to
occur
in
PWSs
at
levels
of
public
health
concern.
National
monitoring
data
indicate
that
metribuzin
is
infrequently
detected
in
public
water
supplies.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
metribuzin
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
and
in
the
regulatory
determination
(
USEPA
2001d)
and
health
effects
(
USEPA
2003d)
support
documents
for
metribuzin.

F.
Naphthalene
Description:
Naphthalene
(
CASRN
91
 
20
 
3)
is
a
VOC
that
is
naturally
present
in
fossil
fuels,
such
as
petroleum
and
coal,
and
is
formed
when
wood
or
tobacco
are
burned.
Naphthalene
is
produced
in
commercial
quantities
from
either
coal
tar
or
petroleum.
Most
naphthalene
use
(
60%)
is
as
an
intermediary
in
the
production
of
phthalate
plasticizers,
resins,
phthaleins,
dyes,
pharmaceuticals,
and
insect
repellents.
Crystalline
naphthalene
is
used
as
a
moth
repellent
and
as
a
solid
block
deodorizer
for
diaper
pails
and
toilets.
The
major
source
of
human
exposure
to
naphthalene
is
through
the
use
of
moth­
balls
containing
naphthalene.
This
exposure
can
be
from
breathing
the
vapors
or
handling
the
mothballs.
People
also
may
be
exposed
by
breathing
tobacco
smoke
and
air
near
industries
that
use
or
produce
naphthalene.
Usually
naphthalene
is
not
found
in
water
because
it
evaporates
or
biodegrades
quickly.
When
it
is
found
in
water,
it
is
usually
at
levels
lower
than
0.01
mg/
L
(
ATSDR
1995).
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
naphthalene
with
a
NPDWR
at
this
time,
because
it
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Naphthalene
is
not
known
to
occur
in
PWSs
at
levels
of
public
health
concern.
National
monitoring
data
indicate
that
naphthalene
is
infrequently
detected
in
public
water
supplies.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
naphthalene
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
and
in
the
regulatory
determination
(
USEPA
2001e)
and
health
effects
(
USEPA
2003e)
support
documents
for
naphthalene.

G.
Sodium
Description:
Sodium
(
CASRN
7440
 
23
 
5)
is
the
sixth
most
abundant
element
on
earth
and
is
widely
distributed
in
soils,
plants,
water,
and
foods.
Ground
water
typically
contains
higher
concentrations
of
minerals
including
sodium
salts
than
do
surface
waters.
In
addition
to
naturally
occurring
sources
of
sodium,
sodium
compounds
are
used
in
deicing
roads,
as
water
treatment
chemicals,
and
in
domestic
water
softeners.
Sewage
effluents
can
also
contribute
significant
quantities
of
sodium
to
water.
Sodium
is
an
essential
trace
element,
and
adequate
levels
of
sodium
are
required
for
good
health.
Food
is
the
main
source
of
daily
human
exposure
to
sodium,
primarily
in
the
form
of
sodium
chloride
(
table
salt).
Most
of
the
sodium
in
our
diet
is
added
during
food
processing
and
preparation.
Agency
Findings:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
sodium
with
a
NPDWR
at
this
time,
because
it
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
The
contribution
of
drinking
water
to
daily
sodium
intake
is
very
small
when
compared
to
the
total
dietary
intake.
Short­
term
excursions
beyond
the
benchmark
values
pose
no
adverse
health
risk
for
most
individuals,
including
the
majority
of
persons
with
hypertension.
Sodium
in
drinking
water
is
a
very
small
contributor
to
daily
dietary
intake
and
the
levels
at
which
sodium
intake
can
contribute
to
increasing
the
blood
pressure
of
individuals
with
normal
blood
pressures
are
not
clearly
established.
The
Agency
currently
does,
however,
require
monitoring
for
sodium
at
the
entry
point
to
the
distribution
system
and
that
results
be
reported
annually
to
public
health
officials
for
surface
water
systems,
and
every
three
years
for
ground
water
systems
(
as
defined
in
40
CFR
141.41).
The
water
supplier
must
report
sodium
test
results
to
local
and
State
public
health
officials,
unless
this
responsibility
is
assumed
by
the
State.
This
requirement
is
intended
to
provide
the
public
health
community
with
information
on
sodium
levels
in
drinking
water
to
be
used
in
counseling
patients
and
is
the
most
direct
route
for
gaining
the
attention
of
the
affected
population.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
sodium
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
as
well
as
in
the
regulatory
determination
(
USEPA
2001f)
support
document
for
sodium.
EPA
is
issuing
a
final
Drinking
Water
Advisory
for
sodium
concurrent
with
today's
action
(
USEPA
2003f).
The
sodium
advisory
provides
guidance
to
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communities
that
might
be
exposed
to
elevated
concentrations
of
sodium
chloride
or
other
sodium
salts
in
their
drinking
water.
This
sodium
advisory
also
provides
appropriate
cautions
for
individuals
on
low­
sodium
or
sodiumrestricted
diets.

H.
Sulfate
Description:
Sulfate
(
SO4
¥
2,
CASRN
14808
 
79
 
8)
exists
in
a
variety
of
inorganic
salts.
Sulfate
salts
such
as
sodium,
potassium,
and
magnesium
are
very
water
soluble
and
are
often
found
in
natural
waters.
Sulfate
salts
of
metals
such
as
barium,
iron,
or
lead
have
very
low
water
solubility.
Sulfate
is
found
in
soil,
sediments,
and
rocks
and
occurs
in
the
environment
as
a
result
of
both
natural
processes
and
human
activities.
Sulfate
compounds
are
used
for
a
variety
of
commercial
and
industrial
purposes.
Sulfate
may
enter
surface
or
ground
water
as
a
result
of
discharge
or
disposal
of
sulfate­
containing
wastes.
In
addition,
sulfur
oxides
produced
during
the
combustion
of
fossil
fuels
are
transformed
to
sulfuric
acid
in
the
atmosphere.
Through
precipitation
(
acid
rain),
sulfuric
acid
can
enter
surface
waters,
lowering
the
pH
and
raising
sulfate
levels.
Sulfate
is
present
in
the
diet.
A
number
of
food
additives
are
sulfate
salts
and
most
(
such
as
copper
sulfate
and
zinc
sulfate)
are
approved
for
use
as
nutritional
supplements.
Sulfate
may
have
adverse
health
affects
on
persons,
primarily
through
its
laxative
effect
following
high­
level,
acute
exposures.
The
adverse
health
effect
from
ingesting
high
levels
of
sulfate
is
increased
water
in
the
fecal
matter
(
diarrhea),
possibly
contributing
to
dehydration.
Because
local
populations
usually
acclimate
to
high
sulfate
levels,
the
impact
is
primarily
on
infants,
transient
populations
(
e.
g.,
business
travelers,
visitors,
and
vacationers),
and
new
residents.
Agency
Finding:
After
reviewing
the
best
available
public
health
and
occurrence
information,
EPA
has
made
the
determination
not
to
regulate
sulfate
with
a
NPDWR
at
this
time,
because
it
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Although
sulfate
occurs
in
many
PWSs
nationally,
the
weight
of
evidence
suggests
that
the
adverse
health
effect
is
generally
mild,
of
short
duration,
and
generally
occurs
at
concentrations
considerably
greater
than
500
mg/
L,
except
in
very
limited
circumstances
when
sulfate
co­
occurs
with
magnesium
and
high
total
dissolved
solids,
which
exacerbate
its
laxative
effects.
EPA
is
issuing
a
final
Drinking
Water
Advisory
to
provide
guidance
to
communities
that
may
be
exposed
to
drinking
water
with
high
sulfate
concentrations.
A
complete
review
of
EPA's
analysis
of
the
health
effects,
occurrence,
and
exposure
for
sulfate
were
presented
in
the
June
2002
notice
(
USEPA
2002a)
as
well
as
in
the
regulatory
determination
(
USEPA
2001g)
support
document
for
sulfate.
EPA
will
issue
a
final
Drinking
Water
Advisory
for
sulfate
concurrent
with
today's
action
(
USEPA
2003g).
The
advisory
for
sulfate
provides
guidance
to
communities
that
may
be
exposed
to
drinking
water
contaminated
with
high
sulfate
concentrations.
This
advisory
contains
information
of
use
to
sensitive
sub­
populations,
such
as
infants
and
travelers.

VI.
How
Will
EPA
Address
the
Data
Needs
of
the
Remaining
51
CCL
Contaminants?
The
Agency
continues
to
conduct
research
and/
or
to
collect
occurrence
information
on
the
remaining
CCL
contaminants.
EPA
has
been
conducting
research
to
fill
identified
data
gaps.
The
Agency
will
take
action
as
appropriate
when
information
becomes
available
and
will
not
necessarily
wait
until
the
end
of
the
next
regulatory
determination
cycle
before
making
other
regulatory
determinations.
To
support
decisions
on
CCL
contaminants,
the
Agency
is
required
to
evaluate
when
and
where
these
contaminants
occur,
the
extent
of
exposure,
and
their
risk
to
public
health.
EPA
must
also
determine
if
regulating
the
contaminant
presents
a
meaningful
opportunity
for
reducing
public
health
risk.
Contaminants
deemed
ready
for
regulatory
determination,
which
include
those
that
are
the
subject
of
today's
decisions,
are
determined
to
have
sufficient
data
to
support
a
decision
as
to
whether
or
not
to
regulate
based
on
evaluation
of
both
exposure
and
risk
to
public
health.
The
remaining
51
CCL
contaminants
for
which
decisions
are
not
being
made
today
do
not
have
sufficient
data
to
support
regulatory
decisions.
The
Agency
continues
to
conduct
research
and/
or
collect
occurrence
information
on
these
remaining
contaminants.
The
research
issues
are
broader
than
those
that
EPA
can
address
alone.
It
is
anticipated
that
other
entities
will
be
involved
in
conducting
much
of
the
needed
research
to
support
this
process.
EPA
continues
to
identify
and
develop
new
collaborations
to
conduct
research
and
gather
the
additional
data
to
characterize
occurrence
and
adverse
health
effects
to
support
future
regulatory
determinations
of
CCL
contaminants.
EPA
is
also
engaged
with
our
stakeholders
in
a
NDWAC
work
group
to
refine
the
CCL
listing
process
to
address
emerging
contaminants
for
future
efforts
EPA
is
committed
to
providing
a
means
for
our
stakeholders
to
track
progress
of
research
on
remaining
CCL
contaminants.
The
Agency
is
currently
developing
a
web­
based
system
that
will
be
available
to
the
public
in
2003.
This
website
will
serve
as
a
repository
of
information
on
drinking
water
research
projects
currently
funded
or
performed
by
EPA.

VII.
References
ATSDR,
1993.
Toxicological
Profile
for
Aldrin/
Dieldrin
(
Update).
Atlanta,
Georgia.
U.
S.
Department
of
Health
and
Human
Services,
Public
Health
Service.
184
pp.
ATSDR,
1995.
Toxicological
Profile
for
Naphthalene
(
Update).
Atlanta,
Georgia.
U.
S.
Department
of
Health
and
Human
Services,
Public
Health
Service.
200
pp.
ATSDR,
2000.
Toxicological
Profile
for
Manganese
(
Update).
Atlanta,
Georgia.
U.
S.
Department
of
Health
and
Human
Services,
Public
Health
Service.
466
pp.
and
Appendices.
USEPA,
1997.
Announcement
of
the
Draft
Drinking
Water
Contaminant
Candidate
List;
Notice.
Federal
Register.
Vol.
62,
No.
193,
p.
52193,
October
6,
1997.
USEPA,
1998.
Announcement
of
the
Draft
Drinking
Water
Contaminant
Candidate
List;
Notice.
Federal
Register.
Vol.
63,
No.
40,
p.
10273,
March
2,
1998.
USEPA,
2000.
Methodology
for
Deriving
Ambient
Water
Quality
Criteria
for
the
Protection
of
Human
Health
(
2000).
EPA
 
822
 
B
 
00
 
004.
October
2000.
USEPA,
2001a.
Regulatory
Determination
Support
Document
for
Aldrin
and
Dieldrin.
EPA
815
R
 
01
 
011.
USEPA,
2001b.
Regulatory
Determination
Support
Document
for
Hexachlorobutadiene.
EPA
815
R
 
01
 
009.
USEPA,
2001c.
Regulatory
Determination
Support
Document
for
Manganese.
EPA
815
R
 
01
 
013.
USEPA,
2001d.
Regulatory
Determination
Support
Document
for
Metribuzin.
EPA
815
R
 
01
 
010.
USEPA,
2001e.
Regulatory
Determination
Support
Document
for
Naphthalene.
EPA
815
R
 
01
 
008.
USEPA,
2001f.
Regulatory
Determination
Support
Document
for
Sodium.
EPA
815
R
 
01
 
014.
USEPA,
2001g.
Regulatory
Determination
Support
Document
for
Sulfate.
EPA
815
R
 
01
 
015.
USEPA,
2002a.
Announcement
of
Preliminary
Regulatory
Determinations
for
Priority
Contaminants
on
the
Drinking
Water
Contaminant
Candidate
List.
Federal
Register.
Vol.
67,
No.
106,
p.
38222,
June
3,
2002.
USEPA,
2002b.
Fact
Sheet:
Announcement
of
Preliminary
Regulatory
Determinations
for
Priority
Contaminants
on
the
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Register
/
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68,
No.
138
/
Friday,
July
18,
2003
/
Notices
Drinking
Water
Contaminant
Candidate
List.
EPA
815
 
F
 
02
 
003.
USEPA,
2003a.
Health
Effects
Support
Document
for
Aldrin
and
Dieldrin.
EPA
822
R
 
03
 
001.
USEPA,
2003b.
Health
Effects
Support
Document
for
Hexachlorobutadiene.
EPA
822
R
 
03
 
002.
USEPA,
2003c.
Health
Effects
Support
Document
for
Manganese.
EPA
822
R
 
03
 
003.
USEPA,
2003d.
Health
Effects
Support
Document
for
Metribuzin.
EPA
822
R
 
03
 
004.
USEPA,
2003e.
Health
Effects
Support
Document
for
Naphthalene.
EPA
822
R
 
03
 
005.
USEPA,
2003f.
Drinking
Water
Advisory:
Consumer
Acceptability
Advice
and
Health
Effects
Analysis
on
Sodium.
EPA
822
R
 
03
 
006.
USEPA,
2003g.
Drinking
Water
Advisory:
Consumer
Acceptability
Advice
and
Health
Effects
Analysis
on
Sulfate.
EPA
822
R
 
03
 
007.
USEPA,
2003h.
Health
Effects
Support
Document
for
Acanthamoeba.
EPA
822
R
 
03
 
012.

Dated:
July
11,
2003.

Linda
J.
Fisher,

Acting
Administrator.
[
FR
Doc.
03
 
18151
Filed
7
 
17
 
03;
8:
45
am]

BILLING
CODE
6560
 
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