1
Fact
Sheet:
Announcement
of
Preliminary
Regulatory
Determinations
for
Priority
Contaminants
on
the
Drinking
Water
Contaminant
Candidate
List
1.
What
is
the
Contaminant
Candidate
List?

The
Safe
Drinking
Water
Act
(
SDWA),
as
amended
in
1996,
requires
EPA
to
publish
a
list
of
contaminants
(
referred
to
as
the
Contaminant
Candidate
List,
or
CCL)
to
assist
in
prioritysetting
efforts.
SDWA
also
requires
the
Agency
to
select
five
or
more
contaminants
from
the
current
CCL
and
determine,
by
August
2001,
whether
or
not
to
regulate
these
contaminants
with
a
National
Primary
Drinking
Water
Regulation
(
NPDWR).

The
CCL
was
developed
with
considerable
input
from
the
scientific
community
and
stakeholders.
A
draft
CCL
requesting
public
comment
was
published
in
October
of
1997
and
a
final
in
March
of
1998.
The
CCL
contains
60
contaminants
(
50
chemicals
and
10
microbes)
that
are
not
subject
to
any
current
or
proposed
NPDWRs.

2.
What
contaminants
are
EPA
considering
for
regulation?

In
1998,
20
of
the
60
contaminants
were
classified
as
priorities
for
regulatory
determination
because
it
was
believed
at
that
time
that
there
were
sufficient
data
to
evaluate
both
exposure
and
risk
to
public
health,
and
to
support
a
determination
of
whether
or
not
to
proceed
to
promulgation
of
an
NPDWR.

Since
then,
12
of
the
20
priority
contaminants
were
found
to
have
insufficient
information
to
support
a
regulatory
determination.
In
addition,
sodium
was
added
to
the
list
of
regulatory
determination
priorities.

Below
are
the
9
contaminants
that
have
sufficient
data
and
information
to
consider
for
a
determination
of
whether
or
not
to
regulate.
Please
see
the
appendix
for
summary
information
on
each
contaminant.
°
Acanthamoeba
 
microscopic
amoeba
commonly
found
in
the
environment
°
Aldrin
 
banned
insecticides,
used
primarily
on
corn
and
cotton
°
Dieldrin
 
banned
insecticides,
used
primarily
on
corn
and
cotton
°
Hexachlorobutadiene
 
used
primarily
to
make
rubber
compounds
°
Manganese
 
essential
nutrient,
occurs
naturally,
and
has
a
variety
of
uses
°
Metribuzin
 
herbicide
used
primarily
on
soybeans,
potatoes,
and
alfalfa
°
Naphthalene
 
intermediary
manufacturing
product
and
moth
repellent
°
Sodium
 
essential
nutrient,
naturally
occurring
element
°
Sulfate
 
present
in
the
diet,
naturally
occurring
element
2
3.
What
did
EPA
decide
and
what
happens
next?

Our
preliminary
determination
is
that
regulatory
action
is
not
appropriate
or
necessary
for
any
of
the
nine
contaminants.
After
a
60
day
comment
period
and
stakeholders
meeting,
EPA
will
publish
the
final
determinations
in
late
2002.
Should
the
Agency
determine
that
regulations
are
necessary,
they
must
be
proposed
in
late
2004,
and
promulgated
by
the
summer
of
2005.

4.
What
analyses
did
EPA
undertake
to
make
this
decision?

When
making
a
determination
to
regulate,
SDWA
requires
consideration
of
three
areas:
projected
adverse
health
effects,
extent
of
contaminant
occurrence,
and
whether
regulation
would
present
a
meaningful
opportunity
for
health
risk
reduction
(
see
SDWA
§
1412(
b)(
1)(
A)).

EPA
developed
the
evaluation
approach
based
on
recommendations
from
National
Research
Council
(
NRC)
and
the
National
Drinking
Water
Advisory
Council
(
NDWAC,
one
of
the
formal
means
that
we
work
with
stakeholders
on
drinking
water
issues).
For
each
of
the
nine
contaminants,
EPA
evaluated
the
sufficiency
of
current
analytical
and
treatment
methods;
the
best
available
peer
reviewed
data
on
health
effects;
and
up
to
approximately
seven
million
analytical
records
on
contaminant
occurrence.
For
those
contaminants
with
adequate
methods,
as
well
as
health
effects
and
occurrence
data,
EPA
employed
an
approach
to
assist
in
making
preliminary
regulatory
determinations
that
follows
the
themes
recommended
by
the
NRC
and
NDWAC
to
satisfy
the
three
SDWA
requirements
under
section
1412(
b)(
1)(
A)(
i)­(
iii).
The
process
was
independent
of
many
of
the
more
detailed
and
comprehensive
risk
management
factors
that
will
influence
the
ultimate
regulatory
decision
making
process.
Thus,
a
decision
to
regulate
is
the
beginning
of
the
Agency
regulatory
development
process,
not
the
end.

Specifically,
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
related
bench­
mark
level
for
each
contaminant.
Then,
for
a
given
contaminant
EPA
estimated
the
number
of
public
water
systems
and
population
served
by
those
systems
above
these
bench­
mark
values,
and
the
geographic
distribution
using
a
large
number
of
state
occurrence
data
that
broadly
reflect
national
coverage.
Use
and
environmental
release
information,
and
ambient
water
quality
data,
were
used
to
augment
the
State
data
and
evaluate
the
likelihood
of
contaminant
occurrence.

The
findings
from
these
evaluations
were
used
to
make
a
preliminary
determination
on
whether
to
regulate
a
contaminant
based
on
the
three
SDWA
statutory
requirements.
The
findings
of
these
evaluations
are
summarized
in
the
appendix.

In
addition,
EPA
has
asked
the
Science
Advisory
Board
to
review
the
supporting
data
and
analysis,
the
approach
used
for
making
regulatory
determinations,
and
the
preliminary
regulatory
determinations.
3
5.
Additional
Considerations
EPA
is
only
making
regulatory
determinations
on
CCL
contaminants
that
have
sufficient
information
to
support
a
regulatory
determination
at
this
time.
The
Agency
continues
to
conduct
research
and/
or
to
collect
occurrence
information
on
the
remaining
CCL
contaminants.
EPA
has
been
aggressively
conducting
research
to
fill
identified
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
to
address
an
urgent
threat
to
public
health
(
see
SDWA
section
1412(
b)(
1)(
D));
or
taking
action
on
CCL
contaminants
when
information
becomes
available.
The
Agency
continues
to
conduct
research
and/
or
to
collect
occurrence
information
for
contaminants
on
the
CCL
(
except
the
nine
for
which
preliminary
determinations
are
being
made)
and
may
proceed
with
regulatory
determination
prior
to
the
end
of
the
next
regulatory
determination
cycle.

We
are
soliciting
comment
on
which
of
the
remaining
CCL
contaminants
stakeholders
believe
should
have
the
highest
priority
for
future
regulatory
determinations
and
their
reasons
in
support
of
such
comments.

6.
Where
can
I
find
more
information
about
this
notice
and
the
CCL?

For
general
information
on
the
CCL,
please
visit
the
EPA
Safewater
Web
site
at
http://
www.
epa.
gov/
safewater
or
contact
the
Safe
Drinking
Water
Hotline
at
1­
800­
426­
4791.
The
Safe
Drinking
Water
Hotline
is
open
Monday
through
Friday,
excluding
Federal
holidays,
from
9:
00
a.
m.
to
5:
30
p.
m.
Eastern
Time.
In
addition
to
this
fact
sheet,
the
following
documents
are
electronically
available
to
the
public
at
EPA's
web
site
on
the
CCL:

(
A)
The
Federal
Register
announcing
the
preliminary
regulatory
determinations
for
priority
contaminants
on
the
CCL;
and
(
B)
The
technical
support
documents
for
the
CCL
Regulatory
Determinations
Federal
Register:

<
Analysis
of
National
Occurrence
of
the
1998
Contaminant
Candidate
List
(
CCL)
Regulatory
Determination
Priority
Contaminants
in
Public
Water
Systems.
<
Health
Effects
Support
Document
for
Acanthamoeba
<
Health
Effect
Support
Document
for
Aldrin
and
Dieldrin
<
Regulatory
Determination
Support
Document
for
Aldrin
and
Dieldrin
<
Health
Effects
Support
Document
for
Hexachlorobutadiene
4
<
Regulatory
Determination
Support
Document
for
Hexachlorobutadiene
<
Health
Effects
Support
Document
for
Manganese
<
Regulatory
Determination
Support
Document
for
Manganese
<
Health
Effect
Support
Document
for
Metribuzin
<
Regulatory
Determination
Support
Document
for
Metribuzin
<
Health
Effect
Support
Document
for
Naphthalene
<
Regulatory
Determination
Support
Document
for
Naphthalene
<
Draft
Drinking
Water
Advisory:
Consumer
Acceptability
Advice
and
Health
Effects
Analysis
on
Sodium
<
Regulatory
Determination
Support
Document
for
Sodium
<
Draft
Drinking
Water
Advisory:
Consumer
Acceptability
Advice
and
Health
Effects
Analysis
on
Sulfate
<
Regulatory
Determination
Support
Document
for
Sulfate
For
a
hard
copy
of
this
fact
sheet
(
EPA
815­
F­
02­
003),
the
Federal
Register
notice,
and/
or
any
of
the
supporting
documents
for
the
CCL
Regulatory
Determinations
notice,
please
contact
EPA's
Water
Resource
Center
at
1­
800­
832­
7828.
Appendix
1
CCL
Regulatory
Determination
Information
Sheet
Acanthamoeba
Background
<
Acanthamoeba
are
microscopic
amoeba
commonly
found
in
the
environment.

Adverse
health
effects
<
Several
species
have
been
found
to
infect
humans.
The
two
major
disease
conditions
are
keratitis
and
granulomatous
amoebic
encephalitis
(
GAE).
­
Acanthamoeba
keratitis.
Keratitis,
or
corneal
infection,
occurs
when
amoebas
enter
the
eye
via
contact
lenses
or
through
a
cut
in
the
cornea.
Infection
occurs
predominantly
in
individuals
who
wear
soft
contact
lenses
and
is
thought
to
be
a
consequence
of
improper
storage,
handling,
and
disinfection
of
the
lenses
or
lense
case;
wearing
lenses
in
hot
tubs
and
during
swimming;
and
the
formation
of
bacterial
biofilms
on
contact
lenses
and
lens
storage
cases.
Acanthamoeba
keratitis
is
not
known
to
be
produced
by
ingestion
of
drinking
water,
inhalation
during
showering,
or
other
standard
uses
of
drinking
water.
­
GAE.
Occurs
mostly
in
chronically
ill
individuals
with
compromised
immune
systems.
Routes
of
entry
are
the
respiratory
tract
and
skin
lesions.

Occurrence
and
exposure
<
Acanthamoeba
are
found
worldwide
in
a
wide
range
of
environmental
media,
it
is
assumed
that
finished
drinking
water
may
be
source
of
exposure,
however,
PWSs
do
not
monitor
for
Acanthamoeba.
<
Between
1973
and
1996
an
estimated
700
Acanthamoeba
keratitis
cases
occurred
in
the
U.
S.
There
appears
to
be
an
increased
incidence
in
keratitis
over
the
past
decade
that
may
be
attributed
to
the
increase
in
the
number
of
contact
lens
wearers.
<
GAE
is
not
a
reportable
disease
in
the
U.
S.;
however,
about
110
cases
of
GAE
have
been
reported
world­
wide;
64
cases
have
been
reported
in
the
U.
S.,
of
which
30
cases
were
diagnosed
in
AIDS
patients.
Reports
indicate
that
the
possible
routes
of
entry
of
Acanthamoeba
in
individuals
are
through
the
respiratory
tract
and
from
skin
lesions.
Thus,
it
is
unlikely
that
any
of
the
cases
were
associated
with
ingestion
of
Acanthamoeba
in
drinking
water.

Preliminary
regulatory
determination
<
The
Agency
has
made
the
preliminary
determination
not
to
regulate
Acanthamoeba
with
a
NPDWR
since
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
for
the
people
served
by
public
drinking
water
systems.
Several
species
of
Acanthamoeba
infect
humans
and
can
be
found
worldwide
in
a
range
of
environmental
media
(
e.
g.,
soil,
dust,
and
fresh
water).
Because
of
this,
it
is
assumed
that
finished
drinking
water
may
be
source
of
exposure.
However,
Acanthamoeba
keratitis
is
not
known
to
be
produced
by
ingestion
of
drinking
water,
inhalation
Appendix
2
during
showering,
or
other
standard
uses
of
drinking
water.
Rather,
keratitis
is
associated
with
poor
hygiene
practices
among
contact
lens
wearers.
GAE
has
been
reported
in
a
very
small
number
of
individuals
known
to
be
at
risk
for
developing
this
disease;
there
have
been
a
total
of
64
U.
S.
cases
which
is
a
low
incidence
even
considering
the
possible
vulnerability
of
an
estimated
number
of
immunocompromised
and
diabetic
individuals
of
10
million.
It
is
unlikely
that
any
of
the
cases
were
associated
with
ingestion
of
Acanthamoeba
in
drinking
water.
<
An
effective
means
to
protect
public
health
is
to
identify
those
groups
of
individuals
who
may
be
at
risk
or
more
sensitive
than
the
general
population
to
the
harmful
effects
of
Acanthamoeba
in
drinking
water
and
target
them
with
protective
measures
(
e.
g.,
encourage
contact
lens
wearers
to
follow
manufacturers'
or
health
care
practitioners'
instructions
for
cleaning
and
rinsing
their
contact
lens).
EPA
intends
to
release
a
guidance
document
addressing
the
risks
of
Acanthamoeba
infection.
Appendix
3
CCL
Regulatory
Determination
Information
Sheet
Aldrin
and
Dieldrin
Background
<
Aldrin
and
dieldrin
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.
<
Popular
pesticides
for
corn
and
cotton
from
1950­
1970.
<
Banned
in
1974
except
to
control
termites,
banned
for
all
uses
in
1987.
<
EPA
issued
health
advisories
in
1992
(
aldrin)
and
1988
(
dieldrin).

Adverse
health
effects
<
Both
are
classified
as,
"
likely
to
be
carcinogenic
to
humans."
<
EPA
used
only
the
best
available
peer
reviewed
data
and
analyses
to
characterize
health
effects.
Based
on
this
characterization,
the
Agency
estimated
a
health­
related
benchmark,
or
Health
Reference
Level1
(
HRL
=
0.002
Fg/
L
for
both
aldrin
and
dieldrin),
against
which
to
evaluate
the
occurrence
data.

Occurrence
and
exposure
<
For
the
most
part,
exposure
occurs
when
people
eat
contaminated
foods.
<
Aldrin
and
dieldrin
were
monitored
under
the
Agency's
Unregulated
Contaminant
Monitoring
program2
from
1993­
1999.
<
EPA
estimated
the
number
of
PWSs
with
detections
>
½
HRL
and
>
HRL;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Aldrin
detections
>
½
HRL
and
>
HRL.
0.02%
of
the
reporting
PWSs
(
2
out
of
12,165)
experienced
detections
of
aldrin
at
>
½
HRL,
and
>
HRL
affecting
0.02%
of
the
population
served
(
8,600
out
of
47.8
million
people).
­
Dieldrin
detections
>
½
HRL
and
>
HRL.
0.09%
of
the
reporting
PWSs
(
11
out
of
11,788)
have
detections
of
dieldrin
at
>
½
HRL,
and
>
HRL
0.07%
of
the
population
served
(
32,000
out
of
45.8
million).

Preliminary
regulatory
determination
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
aldrin
or
dieldrin
with
a
NPDWR
since
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
for
the
people
served
by
public
drinking
water
systems.
EPA
recognizes
that
aldrin
and
dieldrin
are
probable
human
carcinogens,
but
the
chemicals
have
been
banned
for
most
uses
since
1974,
and
have
relatively
low
levels
of
occurrence
in
drinking
water
supplies.
It
is
likely
that
there
will
be
so
few
people
exposed
to
aldrin
and
dieldrin
in
their
drinking
water
that
a
national
regulation
to
Appendix
4
control
these
two
pesticides
may
not
be
significant
in
reducing
cancer
risk.
Appendix
5
CCL
Regulatory
Determination
Information
Sheet
Hexachlorobutadiene
Background
°
Used
to
make
rubber
compounds,
also
used
as
a
solvent.

Adverse
health
effects
°
Classified
as,
"
likely
to
be
a
carcinogen
to
humans."
°
EPA
used
only
the
best
available
peer
reviewed
data
and
analyses
to
characterize
health
effects.
Based
on
this
characterization,
the
Agency
estimated
a
health­
related
benchmark,
or
Health
Reference
Level1
(
HRL
=
1
Fg/
L),
against
which
to
evaluate
the
occurrence
data.

Occurrence
and
exposure
°
Most
exposure
to
hexachlorobutadiene
comes
from
breathing
it
in
workplace
air.
People
living
near
hazardous
waste
sites
containing
hexachlorobutadiene
may
be
exposed
to
it
by
breathing
air
or
by
drinking
contaminated
water.
°
Hexachlorobutadiene
was
monitored
under
the
Agency's
Unregulated
Contaminant
Monitoring
program2
from
1988­
1992
("
Round
1")
and
1993­
1999
("
Round
2").
°
EPA
estimated
the
number
of
PWSs
with
detections
>
½
HRL
and
>
HRL;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Round
1
detections
>
½
HRL
and
>
HRL.
0.16%
of
the
reporting
PWSs
(
20
out
of
12,284)
had
detections
>
½
HRL,
affecting
0.57%
of
the
population
served
(
407,000
out
of
71.6
million).
The
percentage
of
reporting
PWSs
with
detections
>
HRL
is
0.11%
(
14
out
of
12,284),
affecting
0.37%
of
the
population
served
(
263,000
out
of
71.6
million).
­
Round
2
detections
>
½
HRL
and
>
HRL.
0.08%
of
the
reporting
PWSs
>
½
HRL
(
18
out
of
22,736),
affecting
2.3%
of
the
population
served
(
1.6
out
of
67
million).
The
percentage
of
the
reporting
PWSs
with
detections
>
HRL
is
0.02%
(
4
out
of
22,736),
affecting
0.005%
of
the
population
served
(
3,350
out
of
67
million).
°
Qualifying
statement
­
Round
1
monitoring
results
are
influenced
by
the
State
of
Florida,
which
may
have
incomplete
and
problematic
data
that
may
inflate
the
occurrence
estimate.
­
Although
the
two
rounds
differ
somewhat
(
for
population­
exposed
to
concentrations
greater
than
the
HRL),
the
differences
are
relatively
small
(
approximately
a
quarter
million),
and
the
maximum
estimate
still
shows
a
very
low
occurrence.
The
lower
of
the
two
rounds
represents
the
more
recent
data.

Preliminary
regulatory
determination
Appendix
6
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
hexachlorobutadiene
with
an
NPDWR
because
the
contaminant
does
not
occur
with
a
frequency,
or
at
levels,
of
public
health
concern.
Monitoring
data
indicate
that
hexachlorobutadiene
is
infrequently
detected
in
public
water
supplies.
In
addition
to
the
fact
that
these
detections
are
low,
it
is
important
to
note
that
when
hexachlorobutadiene
is
detected,
it
very
rarely
exceeds
the
HRL
or
a
value
of
one­
half
the
HRL.
Appendix
7
CCL
Regulatory
Determination
Information
Sheet
Manganese
Background
°
Essential
nutrient,
occurs
naturally
at
low
levels
in
soil,
water,
and
food
°
Variety
of
uses:
production
of
steel,
batteries,
matches,
animal
feed,
ceramics
and
nutritional
supplements.

Adverse
health
effects
°
Manganese
is
needed
for
normal
growth
and
function;
however,
several
diseases
are
associated
with
both
deficiencies
and
excess
intake
of
manganese.
°
Major
source
of
manganese
intake
in
humans
(
with
the
exception
of
possible
occupational
exposure)
is
dietary
ingestion;
however,
manganese
is
not
considered
to
be
very
toxic
when
ingested
with
food,
and
reports
of
adverse
effects
are
rare.
°
Several
reports
of
toxicity
to
humans
exposed
to
manganese
by
inhalation
which
can
lead
to
neurological
symptoms
(
e.
g.,
tremor,
gait
disorders,
etc.).
Much
less
is
known
about
oral
intake
of
manganese.
°
EPA
used
only
the
best
available
peer
reviewed
data
and
analyses
to
characterize
health
effects.
Based
on
this
characterization,
the
Agency
estimated
a
health­
related
benchmark,
or
Health
Reference
Level1
(
HRL
=
300
Fg/
L),
against
which
to
evaluate
the
occurrence
data.

Occurrence
and
exposure
°
Monitored
under
the
NIRS
study3.
°
EPA
estimated
the
number
of
PWSs
with
detections
>
½
HRL
and
>
HRL;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Detections
>
½
HRL.
6.1%
of
the
reporting
ground
water
PWSs
had
detections
>
½
HRL
(
60
out
of
989),
affecting
about
4.6%
of
the
population
served
(
68,200
out
of
1.5
million).
­
Detections
>
HRL.
3.2%
of
the
reporting
ground
water
PWSs
with
detections
>
HRL
(
32
out
of
989)
affecting
2.6%
of
the
population
served
(
39,000
out
of
1.5
million).

Preliminary
regulatory
determination
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
manganese
with
a
NPDWR
because
it
is
generally
not
considered
to
be
very
toxic
when
ingested
with
the
diet
and
since
drinking
water
accounts
for
a
relatively
small
proportion
of
manganese
intake.
Thus,
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Appendix
8
CCL
Regulatory
Determination
Information
Sheet
Metribuzin
Background
°
Herbicide,
applications
primarily
targeted
to
soybeans,
potatoes,
alfalfa,
and
sugar
cane.
°
Geographic
distribution
of
use
reflects
the
distribution
of
these
crops
across
the
U.
S.

Adverse
health
effects
°
Evidence
is
inadequate
to
classify
as
a
human
carcinogen.
°
For
non­
carcinogenic
effects,
the
thyroid
and
liver
are
the
most
sensitive
organs
(
impacting
organ
weight,
serum
levels,
and
enzyme
activity).
°
EPA
used
only
the
best
available
peer
reviewed
data
and
analyses
to
characterize
health
effects.
Based
on
this
characterization,
the
Agency
estimated
a
health­
related
benchmark,
or
Health
Reference
Level1
(
HRL
=
91
Fg/
L),
against
which
to
evaluate
the
occurrence
data.

Occurrence
and
Exposure
°
Monitored
under
the
Agency's
Unregulated
Contaminant
Monitoring
program2
from
1993­
1999.
°
EPA
estimated
the
number
of
PWSs
with
detections
>
½
HRL
and
>
HRL;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Detections
>
½
HRL
or
>
HRL.
No
PWSs
had
a
detections
>
½
HRL
or
>
HRL.

Preliminary
regulatory
determination
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
metribuzin
with
a
NPDWR
because
it
does
not
occur
with
a
frequency,
or
at
levels,
of
public
health
concern.
Appendix
9
CCL
Regulatory
Determination
Information
Sheet
Naphthalene
Background
°
Naturally
present
in
fossil
fuels
and
is
formed
when
wood
or
tobacco
are
burned.
°
Used
in
the
manufacture
of
plastics,
dyes,
solvents,
and
other
chemicals.
°
Crystalline
naphthalene
is
used
as
a
moth
repellent
and
as
a
solid
block
deodorizer
for
diaper
pails
and
toilets.

Adverse
health
effects
°
Classified
as
a
possible
human
carcinogen,
via
inhalation.
°
Effects
on
the
liver
and
eye
(
cataracts)
after
chronic
exposure.
°
High
doses
cause
break
down
of
the
red
blood
cells.
°
EPA
used
only
the
best
available
peer
reviewed
data
and
analyses
to
characterize
health
effects.
Based
on
this
characterization,
the
Agency
estimated
a
health­
related
benchmark,
or
Health
Reference
Level1
(
HRL
=
140
Fg/
L),
against
which
to
evaluate
the
occurrence
data.

Occurrence
and
exposure
°
The
major
source
of
human
exposure
to
naphthalene
is
through
moth­
balls
through
either
breathing
the
vapors
or
handling.
°
People
also
may
be
exposed
by
breathing
tobacco
smoke
and
air
near
industries
that
produce
naphthalene.
°
Usually
naphthalene
is
not
found
in
water
because
it
evaporates
or
biodegrades
quickly.
°
Monitored
under
the
Agency's
Unregulated
Contaminant
Monitoring
program2
from
1988­
1992
("
Round
1")
and
1993­
1999
("
Round
2").
°
EPA
estimated
the
number
of
PWSs
with
detections
>
½
HRL
and
>
HRL;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Round
1
detections
>
½
HRL
and
>
HRL.
0.01%
of
the
reporting
PWSs
(
1
out
of
13,452)
had
detections
at
both
>
½
HRL
and
>
HRL,
affecting
0.007%
of
the
population
served
(
5,400
out
of
77.2
million).
­
Round
2
detections
>
½
HRL
and
>
HRL.
0.01%
of
the
reporting
PWSs
had
detections
>
½
HRL
(
2
out
of
22,923),
affecting
0.002%
of
the
population
served
(
1,300
out
of
67.5
million).
No
PWSs
had
detections
>
HRL.

Preliminary
regulatory
determination
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
naphthalene
with
an
NPDWR
because
it
is
not
known
to
occur
in
public
water
systems
at
levels
of
public
health
Appendix
10
concern.
Monitoring
data
indicate
that
naphthalene
is
infrequently
detected
in
public
water
supplies.
When
naphthalene
is
detected,
it
very
rarely
exceeds
the
HRL
or
a
value
of
one­
half
of
the
HRL.
Appendix
11
CCL
Regulatory
Determination
Information
Sheet
Sodium
Background
°
Essential
nutrient,
naturally
occurring
element
°
Used
in
de­
icing
roads,
water
treatment
chemicals,
domestic
water
softeners
Adverse
health
effects
°
A
large
body
of
evidence
suggests
that
excessive
sodium
intake
may
contribute
to
age­
related
increases
in
blood
pressure
(
hypertension).
High
blood
pressure
is
a
multi­
factorial
disorder
with
dietary
sodium
as
one
of
a
number
of
factors
influencing
its
incidence.
°
EPA
used
only
the
best
available
peer
reviewed
data
and
analyses
to
characterize
health
effects.
Based
on
this
characterization,
the
Agency
estimated
a
health­
related
benchmark
value
based
on
dietary
intake
because
of
the
lack
of
suitable
dose­
response
data.
A
benchmark
value
of
120,000
Fg/
L
was
used
to
evaluate
the
occurrence
data.

Occurrence
and
exposure
°
Food
is
the
main
source
of
exposure,
primarily
in
the
form
of
sodium
chloride
(
table
salt).
°
Discretionary
sodium
intake
is
variable
and
can
be
quite
large.
The
FDA
has
found
that
most
American
adults
tend
to
eat
between
4,000
and
6,000
mg/
day.
°
Sodium­
restricted
diets
range
from
below
1,000
to
3,000
mg/
day.
°
Monitored
under
the
NIRS
study3.
°
EPA
estimated
the
number
of
PWSs
with
detections
>
½
benchamrk
value
and
>
benchmark;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Detections
>
½
benchmark.
22.6%
of
the
reporting
ground
water
PWSs
have
detections
>
½
benchmark
value
(
224
out
of
989)
affecting
approximately
18.5%
of
the
population
served
(
274,000
out
of
1.5
million
people).
­
Detections
>
benchmark.
13.2%
of
the
reporting
ground
water
PWSs
with
detections
>
benchmark
vaule
(
131
out
of
989)
affecting
approximately
8.3%
of
the
population
served
(
123,000
out
of
1.5
million
people).

Preliminary
regulatory
determination
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
sodium
with
an
NPDWR
since
the
amount
of
sodium
in
drinking
water
is
not
projected
to
cause
adverse
health
effects
and
since
drinking
water
accounts
for
a
relatively
small
proportion
of
sodium
intake.
Thus,
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
PWSs.
Appendix
12
°
This
preliminary
decision
is
based
on
the
minor
impact
of
the
sodium
in
drinking
water
when
compared
to
the
sodium
in
foods.
°
There
are
inconsistencies
and
uncertainties
in
the
data
on
the
relationship
between
sodium
intake
and
cardiovascular
disease
for
populations
with
normal
or
subnormal
blood
pressures.
Blood
pressure
is
greatly
influenced
by
nutrients
in
the
diet,
lifestyle,
and
behavioral
patterns
rather
than
sodium
itself.
°
EPA
intends
to
issue
an
advisory
to
provide
guidance
to
communities
that
may
be
exposed
to
elevated
concentrations
of
sodium
chloride
or
other
sodium
salts
in
their
drinking
water.
The
advisory
will
provide
appropriate
cautions
for
individuals
on
low­
sodium
or
sodium­
restricted
diets.
Appendix
13
CCL
Regulatory
Determination
Information
Sheet
Sulfate
Background
°
Present
in
the
diet,
naturally
occurring
element
°
Used
for
a
variety
of
commercial
purposes
°
SDWA
requires
the
following:
­
That
EPA
make
a
determination
whether
to
regulate
sulfate;
and
­
EPA
and
the
CDC
to
conduct
a
study
to
establish
a
dose­
response
relationship
for
adverse
effects
of
sulfate,
including
the
health
effects
that
may
be
experienced
by
sensitive
subpopulations
(
i.
e.,
infants
and
travelers).

Adverse
health
effects
°
Laxative
effect
following
high
acute
exposures
(>
500
mg/
L)
°
Sulfate
Study
­
In
January
of
1999,
EPA
and
the
CDC
completed
the
study
required
by
SDWA.
­
Investigators
were
unable
to
study
infants
because
they
could
not
identify
enough
exposed
individuals
from
which
to
draw
a
study
population.
­
In
experimental
trials
with
adult
volunteers
representing
a
transient
population,
the
investigators
did
not
find
an
association
between
acute
exposure
to
sodium
sulfate
in
tap
water
and
reports
of
diarrhea.
°
Sulfate
Workshop
­
As
a
supplement
to
the
Sulfate
Study,
the
CDC,
in
coordination
with
EPA,
convened
an
expert
workshop,
open
to
the
public,
in
September
of
1998.
­
Expert
scientists
reviewed
the
literature
and
the
Sulfate
Study
results
and
favored
a
health
advisory
for
sulfate­
containing
drinking
water
levels
greater
than
500
mg/
L.
­
The
most
sensitive
endpoint
was
considered
to
be
diarrhea.
°
EPA
adopted
the
recommendation
by
experts
at
the
Sulfate
Workshop
of
500
mg/
L
as
a
healthrelated
benchmark,
or
Health
Reference
Level1
(
HRL),
against
which
to
evaluate
the
occurrence
data.

Occurrence
and
exposure
°
Monitored
under
the
Agency's
Unregulated
Contaminant
Monitoring
program2
from
1993­
1999.
°
EPA
estimated
the
number
of
PWSs
with
detections
>
½
HRL
and
>
HRL;
the
population
served
at
these
bench­
mark
values;
and
the
geographic
distribution
using
a
large
number
of
State
occurrence
data
that
broadly
reflect
national
coverage.
­
Detections
>
½
HRL.
5%
of
the
reporting
PWSs
had
detections
>
½
HRL
(
820
out
of
16,495
PWSs),
affecting
about
10.2%
of
the
population
served
(
5.1
million
out
of
50.4
Appendix
14
million
people).
­
Detections
>
HRL.
1.8%
of
the
reporting
PWSs
had
detections
>
HRL
(
300
out
of
16,495
PWSs),
affecting
about
0.9%
of
the
population
served
(
448,300
out
of
50.4
million
people).

Preliminary
Regulatory
Determination
°
The
Agency
has
made
the
preliminary
determination
not
to
regulate
sulfate
with
an
NPDWR
since
regulation
would
not
present
a
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
public
drinking
water
systems.
°
This
preliminary
decision
is
based
on
the
weight
of
evidence
suggesting
that
the
risk
of
adverse
health
effects
to
the
general
population
is
limited
and
acute
(
a
short
duration
laxative­
related
response)
and
occurs
at
high
drinking
water
concentrations
(>
500
mg/
L,
and
in
many
cases
>
1,000
mg/
L).
°
In
addition,
either
people
develop
a
tolerance
for
high
concentrations
of
sulfate
in
drinking
water,
or
they
decrease
the
amount
of
the
water
they
drink
at
one
time,
most
likely
because
of
the
taste
of
the
water
(
the
taste
threshold
is
250
mg/
L).
°
EPA
intends
to
issue
an
advisory
to
provide
guidance
to
communities
that
may
be
exposed
to
drinking
water
contaminated
with
high
sulfate
concentrations.
Appendix
15
Foot
notes
1For
hexachlorobutadiene,
manganese,
metribuzin
and
naphthalene
EPA
derived
a
health­
related
benchmark,
or
"
HRL",
against
which
to
evaluate
the
occurrence
data
using
the
RfD
approach
as
follows:
HRL
=
(
RfD
x
BW)/
DW
x
RSC.
Where:
RfD
=
Reference
Dose
BW
=
Body
weight
for
and
adult,
assumed
to
be
70
kg
DW
=
Drinking
water
consumption,
assumed
to
be
2
L/
day
RSC
=
The
relative
source
contribution,
or
the
level
of
exposure
believed
to
result
from
drinking
water
when
compared
to
other
sources
(
e.
g.,
air),
and
is
assumed
to
be
20%
for
the
HRL
unless
noted
otherwise.
The
HRL's
for
sulfate
and
sodium
are
unique
to
each
contaminant.
The
available
data
do
not
support
the
derivation
of
an
RfD
for
sulfate.
However,
500
mg/
L
is
a
concentration
at
which
adverse
effects
did
not
occur
in
any
of
the
reported
studies.
This
value
was
used
as
the
HRL.
The
value
used
to
evaluate
the
occurrence
data
is
not
designated
as
an
HRL
because
of
the
lack
of
suitable
dose­
response
data
and
the
considerable
controversy
regarding
the
role
of
sodium
in
the
etiology
of
hypertension.
Instead
a
benchmark
value
is
used.
The
benchmark
for
sodium
was
derived
from
the
recommended
daily
dietary
intake
(
2.4
g/
day)
as
dissolved
in
2
liters
of
water
(
1.2
g/
L).
It
is
important
to
note
that
the
recommended
intake
is
not
related
directly
to
dose­
response
information
and
is
lower
than
most
estimates
of
the
present
average
daily
intake
of
the
U.
S.
population.
A
RSC
of
10%
was
applied
in
recognition
that
foods
and
discretional
use
of
table
salt
are
the
major
source
of
sodium
exposure.
This
results
in
a
benchmark
value
of
120
mg/
L,
assuming
2
liters
of
water
per
day
(
i.
e.,
2,400
mg/
day/
2L
x
10%
=
120
mg/
L).

2Occurrence
data
for
most
of
the
regulatory
determination
priority
contaminants
(
aldrin,
dieldrin,
hexachlorobutadiene,
metribuzin,
naphthalene,
and
sulfate)
are
from
the
monitoring
results
(
State
finished
drinking
water
occurrence
data)
under
the
Agency's
Unregulated
Contaminant
Monitoring
(
UCM)
program.
These
data
form
part
of
the
Agency's
basis
for
its
estimates
of
national
occurrence.
The
UCM
program
was
initiated
in
1987
to
fulfill
a
SDWA
requirement
of
the
1986
amendments
that
PWSs
[
all
non­
purchased
community
water
systems
(
CWSs)
and
non­
purchased
non­
transient
non­
community
water
systems
(
NTNCWS)]
monitor
for
specified
"
unregulated"
contaminants
to
gather
scientific
information
on
their
occurrence
for
future
regulatory
decision
making
purposes.
The
UCM
program
was
implemented
in
two
phases,
or
"
rounds."
The
first
round
of
UCM
monitoring
began
in
1987,
and
the
second
in
1993.
EPA
reviewed,
edited
and
filtered
the
data
to
meet
various
data
quality
objectives
for
the
purposes
of
this
analysis.
Only
data
meeting
the
quality
objectives
described
below
were
used.
Round
1
consists
of
data
from
24
States
with
approximately
3.3
million
analytical
records
from
approximately
22,000
PWSs.
Round
2
of
data
from
20
States
with
approximately
3.7
million
records
from
slightly
more
than
27,000
PWSs.
The
actual
number
of
systems
and
records
varies
for
each
contaminant
according
to
the
number
of
reported
records
for
a
particular
contaminant.
An
additional
EPA
study
conducted
in
the
mid­
1980s,
the
National
Inorganic
and
Radionuclide
Survey
(
NIRS),
provides
a
statistically
representative
sample
of
the
national
occurrence
of
many
regulated
and
unregulated
inorganic
contaminants
in
ground
water
CWSs.
Appendix
United
States
Environmental
Protection
Agency
April
2002
Office
of
Water
(
4607M)
EPA
815­
F­
02­
003
www.
epa.
gov/
water
16
3An
additional
EPA
study
conducted
in
the
mid­
1980s,
the
National
Inorganic
and
Radionuclide
Survey
(
NIRS),
provides
a
statistically
representative
sample
of
the
national
occurrence
of
many
regulated
and
unregulated
inorganic
contaminants
in
ground
water
CWSs.
The
NIRS
database
includes
manganese
and
sodium
and
provides
contaminant
occurrence
data
from
989
community
water
systems
served
by
ground
water.
The
NIRS
does
not
include
surface
water
systems.
The
selection
of
CWSs
included
in
NIRS
was
designed
so
that
the
contaminant
occurrence
results
are
statistically
representative
of
national
occurrence
at
CWSs
using
ground
water
sources
(
the
survey
was
focused
on
ground
water
systems,
in
part,
because
ground
water
has
a
higher
occurrence
and
concentrations
of
naturally
occurring
IOCs).
Most
of
the
NIRS
data
are
from
smaller
systems
(
based
on
population
served)
and
each
of
the
989
statistically
randomly
selected
CWSs
was
sampled
at
a
single
time
between
1984
and
1986.
The
NIRS
data
were
collected
from
ground
water
CWSs
in
49
States.
Data
were
not
available
for
the
State
of
Hawaii.
NIRS
data
were
designed
to
be
stratified
based
on
system
size
(
population
served
by
the
system),
and
uniform
analytical
detection
limits
were
employed.
