RESPONSE
DOCUMENT
Response
to
Public
Comment
on
"
Drinking
Water
Contaminant
Candidate
List
2;
Notice",
April
2,
2004
(
69
FR
17406)

February
2005
U.
S.
Environmental
Protection
Agency
Office
of
Water
Office
of
Ground
Water
and
Drinking
Water
Washington,
D.
C.
20004
1
TABLE
OF
CONTENTS
I.
INTRODUCTION
AND
OVERVIEW
OF
PUBLIC
COMMENTERS
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3
II.
PUBLIC
COMMENTS
AND
EPA
RESPONSES
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5
1.0
General
Comments
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5
2.0
CCL
Background
and
Summary
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7
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
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8
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
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8
3.1.1
Organizing
and
Extracting
the
Data
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9
3.1.1
Organizing
and
Extracting
the
Data
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10
3.1.1.1
Comments
Supporting
EPA's
Approach
for
Evaluating
and
Screening
Available
Chemical
Contaminant
Data
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10
3.1.1
Organizing
and
Extracting
the
Data
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12
3.1.1.2
Comments
Critical
of
EPA's
Approach
for
Evaluating
and
Screening
Available
Chemical
Contaminant
Data
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12
3.1.3
Research
and
Data
Collection
for
Contaminants
on
the
1998
CCL
.
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14
3.1.3.2
Comments
Critical
of
EPA's
Research
on
Health
Effects,
Treatment,
and
Analytical
Methods
and
Data
Collection
on
Occurrence
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14
3.1.4
Development
of
an
Improved
Classification
Process
for
Future
CCLs
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18
3.14.1
Comments
Supporting
EPA's
Approach
for
Developing
an
Improved
Classification
Process
for
Future
CCLs
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18
3.3
Comments
on
EPA's
Draft
CCL
2
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21
3.3.1
Comments
Supporting
EPA's
Draft
CCL
2
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21
3.3.2
Comments
Critical
of
EPA's
Draft
CCL
2
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22
3.4
Other
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24
3.4.1
Update
CCL
2
Research
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25
3.4.2
Regenerate
CCL
1
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27
3.4.3
Add
NDMA
and
enterotoxigenic
Escherichia
coli
(
E.
coli)
to
CCL
.
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28
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
.
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30
4.1
Comments
on
Screening
of
the
Universe
of
Contaminants
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30
4.1.2
Comments
Critical
of
the
NRC's
Approach
for
Screening
the
Universe
of
Contaminants
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30
4.2
Comments
on
the
Approach
for
Compiling
the
Preliminary
CCL
(
PCCL)
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31
4.2.2
Comments
Critical
of
the
NRC's
Approach
for
Compiling
the
PCCL
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31
4.3
Comments
on
the
Approach
for
Contaminant
Selection
from
the
PCCL
to
the
CCL
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32
4.3.2
Comments
Critical
of
the
NRC's
Approach
for
Contaminant
Selection
from
the
PCCL
to
the
CCL
.
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32
4.4
Comments
on
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
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33
4.4.1
Comments
Supporting
the
NRC's
Approach
of
Using
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
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33
2
4.4.2
Comments
Critical
of
the
NRC's
Approach
of
Using
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
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34
4.5
Other
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35
4.5.1
CCL
Transparency
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37
5.0
Implementation
of
NRC's
Recommendations
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40
5.2
Comments
on
the
Ongoing
Analysis
of
the
Classification
Approach
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40
5.2.1
Organizing
and
Extracting
Data
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40
5.2.1.1
Comments
Supporting
EPA's
Approach
for
Organizing
and
Extracting
Data
for
the
CCL
Universe
.
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40
5.2.1.2
Comments
Critical
of
EPA's
Approach
for
Organizing
and
Extracting
Data
for
the
CCL
Universe
.
.
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42
5.2.3
Classifying
Contaminants
from
the
PCCL
to
the
CCL
.
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.
.
44
5.2.3.1
Comments
Supporting
the
Ongoing
Approach
Used
for
Classifying
Contaminants
from
the
PCCL
to
the
CCL
.
.
.
.
.
.
44
5.2.3.2
Comments
Critical
of
the
Ongoing
Approach
Used
for
Classifying
Contaminants
from
the
PCCL
to
the
CCL
.
.
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47
5.2.4
The
VFAR
Concept
and
Classifying
Microorganisms
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48
5.2.4.2
Comments
Critical
of
the
Use
of
the
VFAR
concept
for
Classifying
Microorganisms
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48
5.3
Other
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53
3
I.
INTRODUCTION
AND
OVERVIEW
OF
PUBLIC
COMMENTERS
The
second
Draft
CCL
(
CCL
2)
was
published
in
the
April
2,
2004
edition
of
the
Federal
Register
(
69
FR
17406)
announcing
the
U.
S.
Environmental
Protection
Agency's
(
EPA)
preliminary
decision
to
carry
forward
the
remaining
51
contaminants
on
the
1998
CCL
as
the
Draft
CCL
2,
provide
information
on
EPA's
efforts
to
expand
and
strengthen
the
underlying
CCL
listing
process
to
be
used
for
future
CCL
listings,
and
to
seek
comment
on
the
draft
list
as
well
as
EPA's
efforts
to
improve
the
contaminant
selection
process
for
future
CCLs.
EPA
requested
public
comment
on
the
proposed
list.
Thirteen
comments
were
received
by
the
June
1,
2004
public
comment
deadline.
[
Note:
six
of
the
comments
were
either
cover
letters
or
duplicate
comments.]

The
purpose
of
this
document
is
to
provide
a
comprehensive
summary
of
the
public
comments
on
the
proposed
rule
and
EPA's
responses
to
these
comments.
EPA
has
established
a
docket
for
this
action
under
Docket
ID
No.
OW­
2003­
0028.
All
documents
in
the
docket
are
listed
in
the
EDOCKET
index
at
http://
www.
epa.
gov/
edocket.
Although
listed
in
the
index,
some
information
is
not
publically
available,
i.
e.,
CBI
or
other
information
whose
disclosure
is
restricted
by
statute.
Certain
other
material,
such
as
copyrighted
material,
is
not
placed
on
the
Internet
and
will
be
publically
available
only
in
hard
copy
form.
Publically
available
docket
materials
are
available
either
electronically
in
EDOCKET
or
in
hard
copy
at
the
Water
Docket,
EPA/
DC,
EPA
West,
Room
B102,
1301
Constitution
Avenue,
NW,
Washington,
DC.
The
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.
For
access
to
docket
material,
please
call
(
202)
566­
2426
to
schedule
an
appointment.

EPA
received
comments
from
a
variety
of
organizations,
including
state
drinking
water
agencies
and
related
associations,
public
drinking
water
systems,
national
drinking
water
organizations,
and
academic
institutions.
Table
1
below
provides
the
names
and
affiliations
of
the
major
commenters
and
their
docket
log
identification
number.
Each
comment
is
identified
by
the
Document
ID
numbers
0014
through
0026
that
was
assigned
under
Docket
ID
No.
OW­
2003­
0028.
Comments
ranged
from
an
anonymous
e­
Docket
message
questioning
whether
EPA
is
considering
regulation
of
1,4­
Dioxane
to
documents
with
detailed
explanations
and
comments
on
many
aspects
of
the
Draft
CCL
2.

EPA
received
one
comment
from
an
anonymous
source;
six
comments
from
state
agencies
and
related
associations
(
Texas
Commission
on
Environmental
Quality­
four
comments
[
two
cover
letters,
one
attachment,
and
one
duplicate
paper
copy
of
cover
letter
and
attachment]
and
Association
of
State
Drinking
Water
Administrators
(
ASDWA)­
two
comments
[
cover
letter
and
attachment]);
four
comments
from
public
water
systems
and
related
associations
(
American
Water
Works
Service
Company
(
AWWA)­
two
comments
[
one
duplicate
comment],
Association
of
Metropolitan
Water
Agencies,
and
the
City
of
Austin,
Texas
Water
Utility
),
and
two
from
an
academic
institution
(
Yale
University
School
of
Medicine
[
comments
and
attachments].

The
majority
of
comments
were
supportive
of
the
CCL
process.
The
comments
on
development
of
the
draft
CCL
2
focused
on
two
key
topic
areas:
(
1)
reassembling
the
CCL
taking
new
available
information
into
account,
suggestions
on
information
that
should
be
considered,
and
contaminants
that
should
be
included
or
deleted
from
the
CCL,
and
(
2)
requests
for
information
on
the
status
of
CCL­
related
research.
Comments
on
the
development
of
future
CCLs
focused
on
four
key
topic
areas:
(
1)
expert
judgement
and
transparency,
(
2)
the
role
of
data
quality,
(
3)
a
simplified
approach
with
adaptive
4
management
for
future
CCLs,
and
(
4)
the
role
of
virulence
factor
activity
relationships
(
VFARs).

Table
1.
Commenter
and
Affiliation
by
Docket
Log
I.
D.
Number
Docket
I.
D.
Commenter
Name
Commenter
Affiliation
Other
0014
Anonymous
Unknown
State
Drinking
Water
Agencies
and
Related
Associations
0015
Daniel
Burke
(
cover
letter)
Texas
Commission
on
Environmental
Quality
0016
Glenn
Shankle
(
cover
letter)
Texas
Commission
on
Environmental
Quality
0017
Comments
(
electronic
attachment
for
0015
and
0016)
Texas
Commission
on
Environmental
Quality
0021
Glenn
Shankle
(
paper
copy
duplicate
of
0017)
Texas
Commission
on
Environmental
Quality
0022
Matt
Corson
(
electronic
cover
letter)
Association
of
State
Drinking
Water
Administrators
0023
James
D.
Taft
(
paper
copy
cover
letter
and
comments
of
0022)
Association
of
State
Drinking
Water
Administrators
Public
Water
Systems,
Water
System
Operators,
and/
or
Local
Water
Agencies
0018
Diane
VanDe
Hei
Association
of
Metropolitan
Water
Agencies
0019
Thomas
W.
Curtis
American
Water
Works
Association
0020
Thomas
Curtis
(
Docket
duplicate
of
0019)
American
Water
Works
Association
0024
Chris
Lippe,
P.
E.
City
of
Austin
Water
Utility
(
Texas)

Academic
Institution
0025
Stephen
C.
Edberg,
Ph.
D,
A.
B.
M.
M.
Yale
University
School
of
Medicine
0026
Attachment
for
0025
Yale
University
School
of
Medicine
5
II.
PUBLIC
COMMENTS
AND
EPA
RESPONSES
1.0
General
Comments
1.0
General
Comments
Docket
ID
­
Part
#
Comment:
0014
1
Is
EPA
considering
the
regulation
of
1,4­
Dioxane?

Response:
No,
EPA
is
not
considering
the
regulation
of
1,4­
Dioxane
at
this
time
because
it
is
not
on
the
current
CCL.
The
CCL
is
the
primary
source
of
priority
contaminants
for
evaluation
by
EPA's
drinking
water
program.
Contaminants
on
the
CCL
are
currently
not
subject
to
any
proposed
or
promulgated
national
primary
drinking
water
regulation,
but
are
known
or
anticipated
to
occur
in
public
water
systems,
and
may
require
regulation
under
SDWA.
The
EPA
conducts
research
on
health
effects,
analytical
methods,
contaminant
occurrence,
treatment
technologies,
and
treatment
effectiveness
for
priority
drinking
water
contaminants
on
the
CCL.
The
Agency
also
develops
drinking
water
guidance
and
health
advisories,
and
makes
regulatory
determinations
for
contaminants
on
the
CCL.
This
contaminant
may
be
considered
as
part
of
the
CCL
3
listing
process.

Docket
ID
­
Part
#
Comment:
0018
1
AMWA
supports
the
CCL
process.
The
SDWA
states
that
the
Administrator
shall
regulate
contaminants
that
will
provide
a
"
meaningful
opportunity
for
health
risk
reduction
for
persons
served
by
public
water
systems"
(
Sec.
1412
(
b)(
1)(
A)(
iii)).
With
this
end
goal
in
mind,
the
CCL
process
must
have
a
clear
focus
on
listing
contaminants
on
the
CCL
that
have
an
adverse
effect
on
public
health,
and
are
likely
to
occur
in
drinking
water
(
Sec.
1412
(
b)(
1)(
A)(
i
and
ii)).
Listing
contaminants
on
the
CCL
therefore
provides
EPA
with
the
ability
to
focus
precious
research
dollars
on
those
chemical
and
microbial
contaminants
that
are
a
potential
health
risk
to
drinking
water
consumers.

The
CCL
process
is
a
mechanism
that
has
been
legislated
to
help
the
Agency
effectively
determine
which
contaminants
to
regulate.
AMWA
supports
the
process
and
believes
Congress
intended
it
to
be
the
future
of
determining
drinking
water
regulations.
AMWA
therefore
encourages
EPA
to
work
to
integrate
this
process
into
its
regulatory
and
research
programs
as
it
believes
Congress
intended.

Response:
EPA
agrees
and
has
made
the
CCL
process
central
to
its
drinking
water
research
and
regulating
program.

Docket
ID
­
Part
#
Comment:
0023
4
With
respect
to
future
CCL
development,
states
support
EPA's
efforts
in
which
it
engaged
the
NRC
and
the
National
Drinking
Water
Advisory
Council
(
NDWAC)
to
improve
the
CCL
listing
process.
States
believe
that
the
information
obtained
from
these
two
entities
will
allow
6
EPA
to
develop
a
broader,
more
systematic
approach
for
selecting
contaminants
for
the
CCL.

Response:
EPA
agrees
and
intends
on
using
such
an
approach
for
CCL
3.
7
2.0
CCL
Background
and
Summary
2.0
CCL
Background
and
Summary
Docket
ID
­
Part
#
Comment:
0017
1
We
support
the
EPA
efforts
to
incorporate
sound
science,
occurrence
information
and
healthrisk
based
priority
setting
into
the
regulatory
development
process.

Response:
EPA
believes
that
the
CCL
process
appropriately
prioritizes
SDWA
regulatory
development.

Docket
ID
­
Part
#

Comment:
0019/
20
26
A
web­
based
research
inventory
was
to
be
available
to
the
public
in
2003
(
DRINK).
This
tool
was
unveiled
on
EPA's
web
site
in
May
2004,
during
the
CCL
2
proposal
comment
period.
EPA
does
not
address
it
in
the
CCL
2
proposal.

Response:
EPA
agrees
that
the
status
of
CCL­
related
research
should
be
publically
available.
The
Agency
has
taken
a
number
of
steps
to
provide
this
information
through
its
websites
and
in
documents
it
has
published.
EPA's
Office
of
Ground
Water
and
Drinking
Water
Drinking
Water
Research
Information
Network
(
DRINK),
found
at
http://
www.
epa.
gov/
safewater/
drink/
intro.
html,
is
a
publicly
accessible,
web
based
system
that
tracks
over
1,000
ongoing
research
projects
conducted
by
EPA
and
other
research
partners
from
national,
regional,
and
international
research
agencies
and
organizations.
The
DRINK
system
stores,
manages,
and
delivers
descriptive
summary
data
on
drinking
water­
related
projects,
including
abstracts,
status
of
projects,
uniform
resource
locators
to
datasets
and
reports,
and
contact
information
on
projects.
8
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
Docket
ID
­
Part
#

Comment:
0017
11
The
CCL
2
process
is
not
currently
adequate
to
elevate
certain
health
risks.
For
example,
nitrite
occurrence
can
exceed
the
maximum
contaminant
level
of
1
milligram
per
liter
at
locations
in
chloramination
distribution
systems
that
are
changing
from
free
chloride
to
combined
chlorine
as
a
result
of
the
Stage
1
Disinfection
Byproducts
Rule.
The
suggested
surveillance
and
nomination
process
to
expedite
new
or
emerging
contaminants
through
the
CCL
process
for
future
CCLs
should
be
taken
into
consideration
for
the
CCL
2.

Response:
EPA
recognizes
that
it
is
important
to
ensure
timely
identification
of
new
and
emerging
drinking
water
contaminants.
Toward
that
end,
EPA
has
considerable
ongoing
surveillance
activity,
ranging
from
ongoing
literature
reviews,
to
attendance
at
professional
meetings,
sponsorship
of
special
meetings
and
special
sessions
at
meetings
dealing
with
drinking
water
issues,
communications
with
researchers
in
the
field,
and
liaisons
with
foreign
institutions.
EPA's
Office
of
Water
maintains
linkage
among
Offices
within
EPA
(
e.
g.,
Office
of
Pesticide
Programs)
and
with
other
agencies
and
organizations
that
play
a
key
role
in
the
surveillance
process
(
e.
g.,
Centers
for
Disease
Control
and
Prevention,
US
Geological
Survey).
Many
offices
within
EPA
are
also
being
called
upon
to
conduct
surveillance
activities.

It
is
important
to
note
the
SDWA
does
not
restrict
the
EPA
from
adding
contaminants
to
the
CCL
at
any
time
and
that
EPA
may
make
regulatory
determinations
for
any
unregulated
contaminant
not
on
today's
CCL
(
see
SDWA
section
1412(
b)(
1)(
B)(
ii)(
III)).
Thus,
the
Agency
has
the
authority
to
act
as
necessary
to
protect
public
health
as
new
information
becomes
available.
9
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
3.1.1
Organizing
and
Extracting
the
Data
Docket
ID
­
Part
#

Comment:
0017
2
Use
of
Surrogates:
When
using
surrogate
data
to
characterize
the
relative
likelihood
of
occurrence,
we
recommend
that
EPA
focus
not
only
on
the
release
of
a
contaminant,
but
also
on
existing
data
showing
the
impact
of
that
release.
As
a
specific
example,
the
TCEQ
has
included
the
contaminants
on
the
CCL
in
the
source
water
assessments,
with
the
exception
of
some
of
the
specific
pathogens.
We
are
continuing
to
develop
relationships
between
potential
sources
and
the
contaminants
on
the
CCL.
We
would
encourage
EPA
to
pursue
further
development
of
contaminant­
to­
source
relationships
in
order
to
better
determine
the
relative
susceptibility
of
public
water
systems
to
these
contaminants.
The
CCL
2
process
is
not
currently
adequate
to
elevate
certain
health
risks.

Response:
This
kind
of
information
will
be
used
in
CCL
3.
10
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
3.1.1
Organizing
and
Extracting
the
Data
3.1.1.1
Comments
Supporting
EPA's
Approach
for
Evaluating
and
Screening
Available
Chemical
Contaminant
Data
Docket
ID
­
Part
#

Comment:
0024
1
Based
on
the
information
provided
in
the
Federal
Register
notice,
it
appears
that
the
EPA
has
an
adequate
methodology
for
screening
the
broad
universe
of
contaminants
and
identifying
those
that
might
belong
on
a
draft
CCL.
Implementing
the
National
Research
Council's
recommendations
will
further
strengthen
the
screening
process.
The
draft
CCL
however
is
overly
broad
and
might
prevent
the
EPA,
with
its
limited
resources,
from
developing
the
necessary
scientific
data
on
which
to
make
regulatory
decisions.

Response:
EPA
disagrees
with
your
statement
that
states
the
CCL
is
overly
broad
and
may
prevent
the
Agency
from
developing
the
necessary
scientific
data
to
base
regulatory
determinations.
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
note,
that
under
the
SDWA,
the
EPA
may
make
regulatory
determinations
for
any
unregulated
contaminant
not
on
today's
CCL
(
see
SDWA
section
1412(
b)(
1)(
B)(
ii)(
III)).
Thus,
the
Agency
has
the
authority
to
act
as
necessary
to
protect
public
health
as
new
information
becomes
available.

Docket
ID
­
Part
#

Comment:
0019/
20
25
AWWA
strongly
supports
the
agency's
efforts
toward
improving
methodologies
for
identifying
and
prioritizing
drinking
water
contaminants
that
merit
regulatory
consideration.
However,
it
is
critical
that
this
new
focus
not
eclipse
longstanding
demands
for
research
in
the
areas
of
analytical
method
development,
occurrence,
health
effects,
and
treatment.
The
magnitude
of
the
challenge
EPA
faces
in
obtaining
and
allocating
resources
to
meet
all
these
research
needs
is
indeed
daunting.
In
its
multi­
year
plan,
the
agency
appropriately
highlights
the
importance
of
research
partnerships
as
a
forum
for
coordinating
research
and
for
leveraging
funding
and
expertise.
Moreover,
effective
outreach
and
transfer
of
scientific
and
technical
information
and
communication
of
research
plans
are
cited
as
important
aspects
of
EPA's
CCL
research
program.
AWWA
encourages
the
agency
to
engage
in
effective
outreach
to
its
current
research
partners
(
i.
e.,
AwwaRF),
other
federal
agencies
(
i.
e.,
Department
of
Homeland
Security,
National
Institutes
of
Health,
etc.),
states,
and
utilities.
AWWA
believes
that
the
extent
to
which
outside
entities,
including
AWWA
and
its
member
utilities,
might
contribute
to
this
overall
effort
will
be
directly
related
to
how
effective
EPA
is
in
communicating
the
progress
and
status
of
current
research
needs.

Response:
EPA
acknowledges
that
entities
outside
of
EPA
contribute
to
the
overall
effort
of
advancing
11
progress
in
CCL­
related
research
and
understands
the
importance
of
communicating
the
status
of
existing
research
needs
and
priorities
to
the
public.
Because
of
this,
EPA
has
made
CCL­
research
related
information
publically
available
through
its
websites,
public
meetings,
and
documents.
12
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
3.1.1
Organizing
and
Extracting
the
Data
3.1.1.2
Comments
Critical
of
EPA's
Approach
for
Evaluating
and
Screening
Available
Chemical
Contaminant
Data
Docket
ID
­
Part
#

Comment:
0019/
20
23
The
proposal
provides
virtually
no
discussion
or
information
about
the
status
of
previously
identified
research
needs
for
the
listed
contaminants.
AWWA
finds
this
to
be
a
serious
omission
in
the
proposal.
EPA
should
clearly
communicate
the
results
of
CCL
contaminant
related
research
to
the
interested
public
and
use
the
available
information
to
inform
the
list
/
do­
not­
list
decision.
Effective
outreach
and
transfer
of
scientific
and
technical
information
and
communication
of
research
plans
are
cited
as
important
aspects
of
EPA's
CCL
research
program.

Response:
EPA
agrees
that
the
status
of
CCL­
related
research
should
be
publically
available.
The
Agency
has
taken
a
number
of
steps
to
provide
this
information
through
its
websites
and
in
documents
it
has
published.

EPA
websites
addressing
CCL­
related
research
information
include
the
following:

°
EPA's
Office
of
Ground
Water
and
Drinking
Water
Drinking
Water
Research
Information
Network
(
DRINK),
found
at
http://
www.
epa.
gov/
safewater/
drink/
intro.
html,
is
a
publicly
accessible,
web
based
system
that
tracks
over
1,000
ongoing
research
projects
conducted
by
EPA
and
other
research
partners
from
national,
regional,
and
international
research
agencies
and
organizations.
The
DRINK
system
stores,
manages,
and
delivers
descriptive
summary
data
on
drinking
water­
related
projects,
including
abstracts,
status
of
projects,
uniform
resource
locators
to
datasets
and
reports,
and
contact
information
on
projects.

°
EPA's
Office
of
Ground
Water
and
Drinking
Water
website
at
http://
www.
epa.
gov/
safewater/
ccl/
cclfs.
html
has
information
on
the
NDWAC
(
e.
g.,
reports,
meeting
announcements,
and
meeting
summaries
which
includes
meetings
of
the
NDWAC
CCL
Work
Group),
monitoring
of
unregulated
contaminants
from
public
water
systems,
the
National
Contaminant
Occurrence
Database,
analytical
methods
for
compliance
monitoring,
and
treatment
technologies.

°
EPA's
Office
of
Research
and
Development
(
ORD)
environmental
information
management
system
website
at
http://
www.
epa.
gov/
eims/
maintains
information
on
EPA
research
projects,
including
project
title,
abstract,
start
and
end
dates,
principal
investigator,
funding,
results
and
publications,
and
related
technical
documents.

°
EPA's
Office
of
Science
and
Technologies
website
at
http://
www.
epa.
gov/
waterscience/
humanhealth/
has
information
on
EPA's
drinking
water
standards,
health
and
consumer
advisories,
criteria
documents,
and
related
technical
documents.
13
A
key
document
addressing
CCL­
related
research
and
information
is
EPA's
Draft
Multi­
Year
Plan
(
MYP)
for
the
drinking
water
research
program.
The
Draft
MYP
describes
the
Agency's
drinking
water
research
program
activities
and
plans
for
fiscal
years
2003
­
2010
(
see
http://
www.
epa.
gov/
osp/
myp/
dw.
pdf).
As
a
tool
for
planning
and
communication,
the
MYP
provides:
(
1)
a
context
for
annual
planning
decisions
and
a
basis
for
describing
the
impacts
of
these
decisions,
(
2)
a
framework
for
integrating
research
on
common
issues
across
the
EPA's
ORD
laboratories
and
centers,
as
well
as
across
the
various
Agency
Goals
established
under
the
Government
Performance
and
Results
Act,
and
(
3)
a
resource
for
communicating
research
plans
and
products
within
ORD
and
with
EPA
programs,
the
regions
and
interested
parties
outside
of
EPA.
MYPs
are
updated
on
a
biennial
basis
to
provide
opportunities
for
making
the
necessary
adjustments
to
the
research
program.

Docket
ID
­
Part
#

Comment:
0019/
20
24
AWWA
believes
that
if
EPA
evaluates
the
data
currently
available,
at
least
some
contaminants
currently
included
in
CCL1
would
not
be
listed
on
CCL
2.
EPA
should
clearly
communicate
the
results
of
CCL
contaminant­
related
research
to
the
interested
public
and
use
the
available
information
to
inform
the
list/
do­
not­
list
decision.

Response:
EPA
believes
that
the
current
CCL
contains
priority
drinking
water
contaminants
and
is
an
appropriate
list
to
maintain
while
work
on
CCL
3
continues.
Where
there
is
adequate
information
about
a
particular
contaminant,
EPA
plans
to
make
a
regulatory
determination
which
will
either
remove
that
contaminant
from
the
CCL
or
start
a
national
rule
making
process
to
set
a
national
primary
drinking
water
regulation.
Additionally,
see
the
response
to
the
comment
0019/
20
part
23,
under
section
3.1.1.2.
14
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
3.1.3
Research
and
Data
Collection
for
Contaminants
on
the
1998
CCL
3.1.3.2
Comments
Critical
of
EPA's
Research
on
Health
Effects,
Treatment,
and
Analytical
Methods
and
Data
Collection
on
Occurrence
Docket
ID
­
Part
#

Comment:
0019/
20
26
In
finalizing
CCL
2
AWWA
believes
it
is
time
for
the
EPA
to
update
stakeholders
on
the
following
specific
activities
that
were
discussed
during
CCL1
development,
explaining
their
current
relevance
(
or
irrelevance
if
that
is
the
case),
current
plans,
and
resource
commitments
if
applicable:

1.
The
National
Contaminant
Occurrence
Database
(
NCOD)
was
slated
to
be
established
by
August
1999
and
was
to
be
considered
for
future
CCLs.
2.
Work
on
21
suspected
endocrine
disruptors
were
deferred
pending
an
imminent
NAS
review,
research
being
conducted
under
OPPTS,
an
imminent
EDSTAC
report
to
be
reviewed
by
EPA
and
FIFRA
SABs,
and
other
activities
coordinated
with
the
EU,
OECD,
and
UNEP.
3.
Work
on
35
pesticides
identified
by
the
OPP
as
having
high
potential
risk
for
leaching
into
groundwater
was
deferred
pending
further
evaluation
of
their
occurrence
potential.
An
occurrence
model,
expected
to
be
ready
for
use
at
the
end
of
1997,
was
to
be
used
by
the
Agency
to
reevaluate
the
pesticides
for
CCL
inclusion.
Note
that
13
of
these
pesticides
are
on
the
draft
CCL
2.
4.
Pending
reassessments
of
pesticide
tolerances
for
raw
and
processed
food
were
cited
as
further
rationale
for
deferring
these
contaminants.
According
to
the
reassessment
schedule
66%
of
applicable
tolerances
and
exemptions
were
to
be
completed
by
August
2002
under
the
FQPA
(
FR
62:
42019).
5.
The
need
for
a
literature
search
on
Pseudomonas
aeruginosa.
6.
ILSI
project
to
evaluate
microbiological
indicators.
7.
EPA
revision
of
risk
assessment
procedures
for
essential
elements,
including
consideration
of
WHO's
pending
document.
8.
Occurrence
data
were
not
available
for
22
chemical
contaminants
monitored
under
the
1993­
1995
UCMR
round.
Eight
of
these
contaminants
still
remain
on
the
proposed
CCL
2
list
without
discussion
of
monitoring
results.

Response:
EPA
agrees
that
the
status
of
CCL­
related
research
should
be
publically
available.
The
Agency's
approach
throughout
the
CCL
process
has
been
and
continues
to
be
to
encourage
a
strong
partnership
with
stakeholders.
The
Agency
has
taken
a
number
of
steps
to
provide
this
information
through
its
websites
and
in
documents
it
has
published.
See
the
response
to
the
comment
0019/
0020
part
23,
under
section
3.1.1.2
above.

Docket
ID
­
Part
#

Comment:
0019/
20
28
The
April
2004
Federal
Register
notice
for
the
CCL
2
proposal
does
not
describe
CCL
related
data
collection
and
research
that
has
been
undertaken
since
CCL1.
The
drinking
water
research
program's
multi­
year
plan
was
mentioned,
but
no
reference
to
this
document
or
to
15
any
other
source
of
information
about
research
project
status
was
provided,
including
DRINK.
The
agency
should
describe
what
has
been
learned
from
research
conducted
through
EPA­
sponsored
projects,
in­
house
EPA
activities,
and
externally­
funded
projects,
and
explain
how
these
results
were
used
to
justify
the
decision
to
carry
over
contaminants
to
CCL
2.
Table
2
in
the
CCL1
Federal
Register
notice
provided
a
very
informative
categorization
of
contaminants
according
to
major
research
needs
(
USEPA
1998).
Stakeholders
are
eager
to
know
how
these
groupings
have
changed
since
1998.
The
agency
should
prepare
an
updated
version
of
Table
2
for
the
final
CCL
2
rule
and
provide
descriptions
or
references
to
specific
information
used
in
making
any
changes
in
categorization
(
i.
e.,
occurrence,
health
effect,
analytical
method,
and
treatment
information
needs).
Additionally,
EPA
should
outline
the
status
and
timetables
for
all
identified
research
needs.

Response:
EPA
agrees
that
the
status
of
CCL­
related
research
should
be
publically
available.
The
Agency
has
taken
a
number
of
steps
to
provide
this
information
through
its
websites
and
in
documents
it
has
published.
See
the
response
to
the
comment
0019/
0020
part
23,
under
section
3.1.1.2
above.

Docket
ID
­
Part
#

Comment:
0019/
20
29
As
a
specific
example,
health
effects,
treatment,
and
analytical
methods
development
were
named
as
research
needs
for
Microsporidia
in
1998.
Since
then,
in
addition
to
in­
house
research
EPA
has
expended
nearly
$
1
million
to
fund
three
Microsporidia
method
development
projects
through
the
EPA
STAR
program.
These
three
projects
have
been
completed
and
results
were
presented
in
Cincinnati
in
2003
(
Research
of
Microorganisms
in
Drinking
Water
Workshop).
Additionally,
in­
house
and
collaborative
research
projects
on
treatment
technologies
for
Microsporidia
have
been
conducted
and
the
results
published
(
Marshall,
2003;
Johnson,
2003;
Hoffman,
2002).
EPA
does
not
cite
or
describe
any
of
this
work
in
the
CCL
2
proposal.
More
generally,
EPA's
2003
Drinking
Water
Research
Program
Multi­
Year
Plan
lists
12
Annual
Performance
Measures
(
APMs)
for
fiscal
year
2003
related
to
CCL
microbes
and
seven
APMs
related
to
CCL
chemical
contaminants.
EPA
should
discuss
the
results
and/
or
status
of
research
related
to
these
APMs,
explain
specifically
how
summary
reports
can
be
located,
and
describe
how
further
progress
can
be
tracked
by
stakeholders
during
the
time
between
CCL
2
and
future
listings.

Response:
EPA
agrees
that
the
status
of
CCL­
related
research
should
be
publically
available.
The
Agency
has
taken
a
number
of
steps
to
provide
this
information
through
its
websites
and
in
documents
it
has
published.
See
the
response
to
the
comment
0019/
0020
part
23,
under
section
3.1.1.2
above.

Docket
ID
­
Part
#

Comment:
0019/
20
30
In
finalizing
CCL
2,
EPA
should
inform
the
interested
public
about
the
agency's
progress
to
date
and
intended
future
path
for
integrating
both
FIFRA
and
endocrine
disruptor
screening
information
into
the
CCL
process.

Response:
16
As
discussed
in
the
draft
CCL
2
notice
(
69
FR
17406),
EPA
plans
to
consider
the
deferred
pesticides
in
the
context
of
an
improved
approach
for
selecting
contaminants
for
future
CCLs
(
CCL
3).
This
will
enable
the
Agency
to
consider
these
contaminants
in
a
consistent,
reproducible
manner
with
a
wide
range
of
other
contaminants.
In
this
regard,
it
is
important
to
note
that
EPA
may
conduct
research,
and
make
regulatory
determinations
for
any
unregulated
contaminant
not
on
today's
CCL
(
see
SDWA
section
1412(
b)(
1)(
B)(
ii)(
III)).
Thus,
the
Agency
has
the
authority
to
act
as
necessary
to
protect
public
health
as
new
information
becomes
available.

As
with
pesticides,
EPA
believes
that
suspected
endocrine
disruptors
should
be
considered
when
the
next
CCL
is
developed.
This
enables
the
Agency
to
use
a
more
refined
and
improved
approach
in
evaluating
these
contaminants.

Docket
ID
­
Part
#

Comment:
0019/
20
34
As
noted
above,
an
important
feature
of
CCL1
was
the
inclusion
of
a
matrix
or
research
needs
(
i.
e.,
Table
2).
It
is
particularly
critical
that
the
agency
clearly
communicate
priorities
for
analytical
method
research,
as
being
able
to
detect
contaminants
at
concentrations
in
the
region
of
interest
is
essential
to
both
occurrence
and
health
effects
research.

Response:
See
response
to
comment
0019/
0020
part
23,
under
section
3.1.1.2.

Docket
ID
­
Part
#

Comment:
0019/
20
35
The
agency
recognized
the
role
of
the
National
Contaminants
Occurrence
Database
(
NCOD)
in
determining
the
CCL
in
its
1997
CCL1
notice
(
Figure
2,
62
Federal
Register
52215).
While
the
NCOD
is
not
the
only
source
of
data
available
to
the
agency,
Congress
clearly
intended
for
the
agency
to
maintain
a
repository
of
occurrence
data
that
could
be
used
to
support
the
CCL
process.
EPA
currently
maintains
the
NCOD
(
http://
www.
epa.
gov/
safewater/
data/
ncod.
html)
and
should
consider
how
NCOD
could
better
serve
the
agency
as
the
CCL
process
evolves.

Response:
The
National
Contaminants
Occurrence
Database
(
NCOD)
is
currently
being
populated
with
compliance
monitoring
occurrence
data,
as
well
as
data
now
being
received
as
part
of
the
UCMR.
For
the
CCL
occurrence
analysis,
EPA
used
the
Round
1
and
Round
2
data
available
in
the
NCOD
at
the
time.
Because
NCOD
is
not
a
quality­
controlled
data
set,
EPA
selected
a
large
subset
of
the
Round
1
and
Round
2
data
by,
for
example,
removing
data
with
obvious
unit
errors
and
data
from
States
that
did
not
report
non­
detects.

The
Agency
is
committed
to
continuing
to
conduct
research
to
fill
identified
data
gaps
and/
or
to
collect
occurrence
information
on
the
remaining
CCL
contaminants
and
will
take
appropriate
action
when
information
becomes
available.

Docket
ID
­
Part
#
17
Comment:
0023
2
However,
states
continue
to
urge
EPA
to
complete
necessary
research
in
order
to
make
regulatory
determinations
on
high
priority
contaminants
such
as
MTBE
and
perchlorate.

Response:
The
Agency
continues
to
conduct
research
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
(
e.
g.,
perchlorate
and
methyl
t­
butyl
ether
(
MTBE)).
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
note,
that
under
the
SDWA,
the
EPA
may
make
regulatory
determinations
for
any
unregulated
contaminant
not
on
today's
CCL
(
see
SDWA
section
1412(
b)(
1)(
B)(
ii)(
III)).
Thus,
the
Agency
has
the
authority
to
act
as
necessary
to
protect
public
health
as
new
information
becomes
available.

Docket
ID
­
Part
#

Comment:
0024
4
30­
Contaminant
Monitoring
Limit.
On
Page
17410
of
the
Federal
Register
notice,
there
is
mention
of
a
30­
contaminant
monitoring
limit
in
each
five­
year
monitoring
cycle
under
the
SDWA's
Unregulated
Contaminant
Monitoring
Rule.
We
feel
that
the
EPA
uses
an
overly
stringent
interpretation
of
this
section
of
the
SDWA
(
Section
1445(
a)(
2)(
B)(
i)).
A
broader
interpretation
would
support
a
limit
on
monitoring
of
30
contaminants
per
public
water
system
rather
than
a
total
of
30
contaminants.
With
a
broader
interpretation
of
the
limit
and
by
applying
statistical
principals
to
sampling
plans
under
the
Unregulated
Contaminant
Monitoring
Rule,
the
EPA
could
gather
occurrence
data
on
60,
90,
or
perhaps
even
120
contaminants
in
a
five­
year
monitoring
cycle.
Considering
that
there
may
be
as
many
as
10,000
potential
contaminants
to
screen
in
preparing
a
CCL,
a
dramatic
increase
in
monitoring
is
justifiable.
The
EPA
should
reconsider
its
interpretation
of
the
30­
contaminant
monitoring
limit
to
support
its
regulatory
program,
especially
since
it
provides
valuable
information
and
adds
little
or
no
additional
costs
to
the
regulated
community.

Response:
The
comment
is
not
germane
to
CCL
2.
EPA
anticipates
publishing
a
preliminary
UCMR
2
in
the
summer
of
2005
and
will
consider
the
comment
at
that
time.
18
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.1
Comments
on
Approach
and
Rationale
for
the
Draft
CCL
2
3.1.4
Development
of
an
Improved
Classification
Process
for
Future
CCLs
3.14.1
Comments
Supporting
EPA's
Approach
for
Developing
an
Improved
Classification
Process
for
Future
CCLs
Docket
ID
­
Part
#

Comment:
0019/
20
1
Evaluations
of
the
CCL
process
by
NRC
and
the
NDWAC
CCL
Workgroup
have
identified
a
number
of
complexities
and
challenges
that
will
be
encountered
in
developing
a
valid
CCL.
AWWA
recommends
that
EPA
continue
diligent
pursuit
both
of
a
short­
term
process
for
developing
the
next
CCL
and
a
long­
term
evolution
of
the
CCL
process.

Response:
The
Agency
agrees
with
the
commenter
that
EPA
will
need
to
continue
to
identify
key
components
for
the
next
CCL
and
that
future
CCLs
will
be
developed
with
the
knowledge
gathered
during
the
initial
development
process.
The
National
Drinking
Water
Advisory
Council
report
(
2004)
provides
a
series
of
recommendations
for
the
Agency
to
consider
as
it
develops
the
CCL
process
for
the
next
and
future
CCLs.
The
National
Drinking
Water
Advisory
Council
recommendations
encourage
the
Agency
to
identify
which
components
can
be
used
for
the
next
CCL
and
how
to
address
challenges
to
improve
the
process
for
future
CCL.
As
the
Agency
evaluates
the
National
Drinking
Water
Advisory
Council
recommendations,
it
will
consider
the
comments
to
move
to
a
more
simplified
approach
for
the
next
CCL.

Docket
ID
­
Part
#

Comment:
0019/
20
2
The
purpose
of
the
CCL
is
to
identify
contaminants
whose
regulation
will
increase
public
health
protection.
The
CCL
also
should
identify
those
contaminants
that
need
to
be
prioritized
for
research.
The
entire
process
that
is
applied
to
contaminants
on
the
CCL
should
focus
on
identifying
those
contaminants
that
are
likely
to
be
found
in
drinking
water
and
are
likely
to
pose
health
risks
to
the
public.
Targeted
research
that
improves
understanding
of
contaminants
and
results
in
appropriate
regulation
will
improve
protection
of
public
health
and
maintain
public
confidence
in
the
CCL
process.

Response:
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
will
take
appropriate
action
when
information
becomes
available.
The
Agency
has
taken
a
number
of
steps
to
provide
this
information
through
its
websites
and
in
documents
it
has
published.
See
the
response
to
the
comment
0019/
0020
part
23,
under
section
3.1.1.2
above.

Docket
ID
­
Part
#

Comment:
0019/
20
3
The
CCL
should
be
a
list
that
prioritizes
research
and
furthers
investigations
into
the
19
occurrence
and
health
effects
of
contaminants.

Response:
EPA
agrees
and
believes
that
the
current
CCL
serves
this
purpose.

Docket
ID
­
Part
#

Comment:
0019/
20
4/
5/
6
AWWA
strongly
encourages
EPA
to
develop
a
CCL
process
not
from
a
theoretical
and
esoteric
perspective,
but
rather
from
a
very
pragmatic
perspective.
Specifically,
the
process
must
have
detailed
protocols
prescribed
that
address
the
following
questions:

1.
How
will
contaminants
to
be
evaluated
be
identified?
2.
What
types
and
quality
of
data
are
required
in
order
to
evaluate
these
contaminants?
3.
Do
the
required
data
exist?
4.
Are
they
accessible?
5.
What
attributes
can
be
applied
that
will
enable
the
evaluators
to
prioritize
contaminants
for
consideration
and
for
further
research?

The
approach
developed
must
be
transparent,
but
it
also
needs
to
be
logistically
possible.
The
approach
adopted
should
be
as
simple
as
possible
and
it
should
be
repeatable.
Although
AWWA
recognizes
that
the
overall
CCL
process
will
evolve
over
time,
there
are
immediate
requirements
for
CCL
3
development
and
for
long­
term
processes
for
future
CCLs.

Response:
The
Agency
agrees
with
the
commenter
that
it
is
important
to
define
components
and
CCL
Process
steps
in
future
CCLs.
The
components
identified
by
the
commenter
are
also
addressed
in
the
National
Drinking
Water
Advisory
Council
report
on
the
CCL
classification
process.
As
the
Agency
evaluates
the
National
Drinking
Water
Advisory
Council
report
recommendations
to
develop
CCL
3
and
future
CCLs
it
will
take
these
comments
under
consideration
as
well.
The
commenters'
recognition
that
the
"
CCL
process
will
evolve
over
time"
is
similar
to
the
National
Drinking
Water
Advisory
Council
recommendation
to
use
an
adaptive
management
approach
to
develop
the
CCL
process.
The
Agency
agrees
with
the
commenter
that
EPA
will
need
to
identify
key
components
for
the
next
CCL
and
future
CCLs.
The
National
Drinking
Water
Advisory
Council
report
also
provides
a
series
of
recommendations
and
considerations
for
the
Agency
to
evaluate
to
develop
the
CCL
process.
These
steps
incorporate
the
commenters'
suggestion
to
consider
the
evaluation
of
information
and
data
quality
considerations,
and
the
components
required
to
develop
the
CCL
Classification
approach.
As
the
Agency
evaluates
the
National
Drinking
Water
Advisory
Council
recommendations,
it
will
also
consider
the
comments
to
move
to
a
more
simplified
approach
for
the
next
CCL.
For
additional
discussion
on
developing
the
CCL
Process
see
response
to
comment
0019/
0020
part
1,
under
section
3.1.4.1.

Docket
ID
­
Part
#

Comment:
0019/
20
7/
8
AWWA
does
not
believe
that
the
agency
will
be
successful
in
advancing
the
CCL
process
unless
it
abides
by
two
fundamental
principles:
20
1.
The
CCL
process
should
be
an
expert
decision­
making
process
assisted
by
decision
support
tools,
not,
as
is
frequently
discussed,
an
automated
algorithm
that
is
periodically
checked
by
experts
for
its
performance.

2.
The
CCL
process
must
evolve
over
time
based
on
sound
principles
and
well­
tested
approaches.
The
agency
must
be
prepared
to
allocate
the
substantial
resources
required
to
adequately
test
and
verify
the
performance
of
such
approaches.

These
two
principles
lead
AWWA
to
believe
that
simpler,
streamlined
approaches,
which
use
only
the
attributes
of
occurrence
and
health
effects,
might
result
in
a
CCL
list
that
will
be
more
effective
in
the
near
term.
This
approach
will
provide
a
logical
and
logistically
possible
platform
from
which
to
develop
more
sophisticated
expert
support
systems.
The
NRC
approach
can
serve
as
a
useful
guidance
for
the
agency's
long­
term
CCL
development
effort.
However,
many
details
and
logistical
issues
would
have
to
be
overcome
to
employ
it
in
CCL
3.

Response:
The
Agency
agrees
that
expert
input
to
a
CCL
process
based
on
sound
principles
are
important
for
the
success
of
the
CCL
program.
The
National
Drinking
Water
Advisory
Council
recommendations
also
note
that
the
process
should
evolve
over
time
and
the
knowledge
gained
in
successive
CCLs.
The
Agency
will
consider
these
comments
as
it
develops
the
CCL
process.

Docket
ID
­
Part
#

Comment:
0019/
20
10
AWWA
believes
that
convening
a
series
of
expert
workshops
on
the
above
topics
is
the
most
practical
approach
to
resolving
many
of
the
issues
facing
EPA.
AWWA
believes
that
for
the
workshops
to
be
effective
there
needs
to
be
extensive
preparation
in
advance
and
the
participants
need
to
be
chosen
for
hands­
on,
in­
depth
review
of
the
subjects.

Response:
The
Agency
agrees
with
the
commenter
that
expert
involvement
in
the
development
of
the
CCL
process
is
an
important
component.
The
Agency
will
consider
the
recommendation
to
use
expert
workshops
as
one
approach
in
developing
the
CCL
process.
The
Agency
will
also
consider
other
approaches
to
include
expert
input
and
inform
stakeholders
and
the
public
on
the
progress
the
Agency
makes
in
developing
the
CCL
process.
21
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.3
Comments
on
EPA's
Draft
CCL
2
3.3.1
Comments
Supporting
EPA's
Draft
CCL
2
Docket
ID
­
Part
#

Comment:
0023
1
With
respect
to
the
contaminants
that
should
be
included
on
the
next
CCL,
states
support
EPA's
preliminary
decision
to
carry
over
the
remaining
51
contaminants
on
the
1998
CCL.

Response:
EPA
agrees
and
has
adopted
this
approach
in
the
final
CCL
2
list.
22
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.3
Comments
on
EPA's
Draft
CCL
2
3.3.2
Comments
Critical
of
EPA's
Draft
CCL
2
Docket
ID
­
Part
#

Comment:
0017
6
With
respect
to
the
microbiological
contaminant
candidates
listed
under
Table
III­
2­
Draft
Drinking
Water
CCL
2,
the
reference
to
"
other
freshwater
algae",
although
carried
over
from
CCL1,
appears
to
be
too
general
to
be
useful.
We
would
encourage
EPA
to
target
specific
constituents
of
concern
(
i.
e.­
specific
algae
or
their
metabolites
that
have
a
known
or
predicted
adverse
impact
on
drinking
water)
for
future
CCL
lists,
not
broad
groups.
Those
algae
that
are
benign
should
not
be
considered
contaminants.

Response:
EPA
will
consider
targeting
specific
constituents
of
concern
(
as
opposed
to
broad
groups)
as
we
develop
an
expanded
comprehensive
system
for
evaluating
a
wider
range
of
existing
information,
identifying
new
data,
and
applying
revised
screening
criteria
for
future
CCL
lists.

Docket
ID
­
Part
#

Comment:
0019/
20
36
The
proposed
CCL
2
clearly
does
not
reflect
any
progress
in
making
the
CCL
process
a
core
program
element,
despite
five
years
in
which
to
make
substantive
progress.
AWWA
realizes
that
the
agency
has
invested
in
two
NRC
reports
and
the
ongoing
NDWAC
Workgroup
process.
Consequently,
AWWA
believes
that
the
agency
must
make
a
serious
commitment
to
advancing
a
pragmatic
process
for
CCL
3.

Response:
EPA
disagrees
that
the
CCL
2
does
not
reflect
any
progress
in
making
the
CCL
process
a
core
program
element.
After
the
1998
CCL
was
published,
the
Agency
asked
the
National
Research
Council
(
NRC),
the
operating
arm
of
the
National
Academy
of
Sciences,
to
review
the
1998
CCL
selection
process
and
provide
recommendations
on
how
the
process
could
be
improved.
These
recommendations
were
developed
over
several
years
and
provided
to
the
Agency
in
late
2001.
The
NRC
recommendations
provided
a
framework
for
evaluating
a
larger
number
of
contaminants
and
making
decisions
about
contaminants,
for
which
data
are
limited,
through
the
use
of
innovative
technologies
and
expert
advice.
The
EPA
requested
the
assistance
of
the
National
Drinking
Water
Advisory
Council
(
NDWAC)
to
evaluate
and
provide
advice
on
implementing
the
NRC's
recommended
classification
process.
A
NDWAC
working
group
met
10
times
from
September
of
2002
to
March
of
2004.
The
NDWAC
presented
the
final
report
to
the
Administrator
on
May
19,
2004.
The
report,
entitled
National
Drinking
Water
Advisory
Council
Report
on
the
CCL
Classification
Process
to
the
U.
S.
Environmental
Protection
Agency
provides
a
detailed
summary
of
the
questions
considered
by
the
NDWAC,
the
analyses
conducted
to
explore
the
questions,
key
points
discussed,
and
the
NDWAC's
recommendations
and
rationale
for
the
recommendations.
The
report
is
available
at
http://
www.
epa.
gov/
safewater/
ndwac/
council.
html.

Additionally,
after
publication
of
the
final
1998
CCL,
EPA
began
collecting
occurrence
data
and
conducting
research
on
the
CCL
contaminants.
Data
collection
efforts
include
assessing
23
the
occurrence
of
contaminants
in
public
water
systems
through
the
Unregulated
Contaminant
Monitoring
Regulation
(
64
FR
50556),
as
well
as
evaluating
occurrence
data
from
national
surveys
and
considering
State­
level
contaminant
occurrence
information.
Research
efforts
focused
on
obtaining
the
information
needed
to
characterize
the
adverse
health
effects
of
contaminants,
drinking
water
treatment
options,
and
the
development
of
analytical
methods
to
detect
contaminants
in
drinking
water.

On
July
18,
2003,
EPA
announced
its
final
determinations
for
a
subset
of
contaminants
on
the
1998
CCL
(
68
FR
42898),
which
concluded
that
sufficient
data
and
information
were
available
to
make
the
determination
that
a
regulation
was
not
appropriate
for
nine
contaminants.
The
Agency
is
preparing
to
make
the
second
round
of
regulatory
determinations
in
the
2006
time­
frame
using
the
data
collected
from
these
activities.

Docket
ID
­
Part
#

Comment:
0025
1
Inadequate
attention
to
host
factors
in
the
generation
of
microbial
disease
by
the
notice.

Response:
The
Agency
agrees
that
the
consideration
of
host
factors
in
microbial
disease
as
an
area
that
should
receive
more
attention.
The
National
Drinking
Water
Advisory
Council
report
also
provides
some
discussion
on
this
topic.
As
the
Agency
develops
the
CCL
process
for
microbial
contaminants
we
will
evaluate
approaches
to
account
for
host
factors
and
the
generation
of
microbial
disease.

Docket
ID
­
Part
#

Comment:
0025
2
Inadequate
attention
to
disease
sequelae.
Nowhere
in
the
regulation
is
disease
sequelae
mentioned.
It
is
not
adequate
to
perform
risk
assessment
solely
on
gastroenteritis
as
the
disease
entity.
.
.
As
part
of
the
an
information
collection
rule
or
by
contact,
the
EPA
should
enhance
its
knowledge
of
disease
sequelae
of
gastrointestinal
pathogens.

Response:
The
Agency
agrees
that
the
consideration
of
disease
sequelae
in
the
selection
of
microbial
contaminants
as
an
area
that
should
receive
more
attention.
The
National
Drinking
Water
Advisory
Council
report
also
provides
some
discussion
on
this
topic,
particularly
in
the
evaluation
of
microbial
contaminants
as
they
move
from
a
preliminary
CCL
to
the
CCL.
As
the
Agency
develops
the
CCL
process
for
microbial
contaminants
we
will
evaluate
approaches
to
account
for
disease
sequelae
of
pathogens.
24
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.4
Other
Docket
ID
­
Part
#

Comment:
0023
3
States
believe
that
a
consistent
national
approach
would
be
more
appropriate
and
encourage
EPA
to
make
regulatory
determinations
on
these
contaminants
as
soon
as
the
necessary
information
becomes
available,
regardless
of
the
timing
of
the
next
round
of
CCL
regulatory
determinations.

Response:
SDWA
does
not
limit
EPA
to
issuing
regulatory
determinations
every
five
years;
EPA
intends
to
make
early
regulatory
determinations
where
necessary
and
appropriate.
25
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.4
Other
3.4.1
Update
CCL
2
Research
Docket
ID
­
Part
#

Comment:
0017
3
Carryover
of
CCL
Contaminants:
EPA
specifically
requested
comment
on
carrying
over
the
51
contaminants
presented
in
the
1998
initial
CCL
to
the
CCL
2.
We
recommend
that
all
occurrence
and
health
risk
data
be
considered
when
making
the
determination
of
whether
to
carry
over
a
contaminant
from
the
previous
CCL.

Response:
EPA
does
not
believe
that
it
is
appropriate
to
create
a
new
CCL,
or
remove
any
contaminants
from
the
CCL,
at
this
time.
Where
there
is
adequate
information
about
a
particular
contaminant,
EPA
plans
to
make
a
regulatory
determination
which
will
either
remove
that
contaminant
from
the
CCL
or
start
a
national
rule
making
process
to
set
a
national
primary
drinking
water
regulation.

Also,
see
the
response
to
the
comment
0019/
20
part
23,
and
0019/
20
part
24
under
section
3.1.1.2.

Docket
ID
­
Part
#

Comment:
0018
6
4.
AMWA
suggests
EPA
include
the
status
of
research
on
CCL
contaminants
that
have
been
on
the
list
since
1997
in
the
final
CCL
2
and
future
list
proposals.
EPA
should
use
the
proposed
CCL
and
future
proposals
as
an
opportunity
to
clearly
communicate
the
progress
and
results
of
research
on
CCL
contaminants.

Response:
See
the
responses
to
the
comments
0019/
20
part
23,
under
section
3.1.1.2.
and
0017
part
3,
under
section
3.4.1.

Docket
ID
­
Part
#

Comment:
0018
7
In
addition,
EPA
should
inform
the
public
about
its
progress
in
considering
information
about
pesticides
under
the
Federal
Insecticide
Fungicide
and
Rodenticide
Act
(
FIFRA).
In
developing
the
first
CCL,
EPA
indicated
that
it
was
deferring
information
under
FIFRA
(
63
Federal
Register
10284,
but
did
not
mention
the
status
of
this
information
in
this
notice
or
in
the
development
of
the
CCL
2.

Response:
As
discussed
in
the
draft
CCL
2
notice
(
69
FR
17406),
EPA
plans
to
consider
the
deferred
pesticides
in
the
context
of
an
improved
approach
for
selecting
contaminants
for
future
CCLs
(
CCL
3).
This
will
enable
the
Agency
to
consider
these
contaminants
in
a
consistent,
reproducible
manner
with
a
wide
range
of
other
contaminants.
In
this
regard,
it
is
important
26
to
note
that
EPA
may
conduct
research,
and
make
regulatory
determinations
for
any
unregulated
contaminant
not
on
today's
CCL
(
see
SDWA
section
1412(
b)(
1)(
B)(
ii)(
III)).
Thus,
the
Agency
has
the
authority
to
act
as
necessary
to
protect
public
health
as
new
information
becomes
available.

Docket
ID
­
Part
#

Comment:
0024
3
It
would
be
appropriate
for
the
EPA
to
update
the
public
on
the
status
of
its
regulatory
efforts
on
these
contaminants
on
a
contaminant­
by­
contaminant
basis.

Response:
See
the
responses
see
to
the
comments
0019/
20
part
23,
under
section
3.1.1.2.
and
0017
part
3,
under
section
3.4.1.
27
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.4
Other
3.4.2
Regenerate
CCL
1
Docket
ID
­
Part
#

Comment:
0017
4
If
updated
health
and
occurrence
information
does
not
support
concerns
for
contaminants
on
previous
CCL
lists,
then
we
recommend
that
previous
CCL
lists
be
reentered
into
the
CCL
process
at
the
CCL
"
Universe"
stage
to
determine
if
further
screening
to
the
future
CCL
lists
would
be
warranted.

Response:
EPA
does
not
believe
that
it
is
appropriate
to
create
a
new
CCL,
or
remove
any
contaminants
from
the
CCL,
at
this
time.
Where
there
is
adequate
information
about
a
particular
contaminant,
EPA
plans
to
make
a
regulatory
determination
which
will
either
remove
that
contaminant
from
the
CCL
or
start
a
national
rule
making
process
to
set
a
national
primary
drinking
water
regulation.
Also
see
response
to
comment
0019/
20
part
24
under
3.1.1.2.

Docket
ID
­
Part
#

Comment:
0019/
20
22
EPA
explicitly
requested
comment
on
the
agency's
decision
to
carry
over
the
remaining
51
contaminants
from
the
1998
CCL1
to
CCL
2.
AWWA
believes
each
CCL
should
be
considered
anew.
It
should
be
regenerated
and,
if
existing
contaminants
warrant
inclusion,
they
will
emerge
thorough
the
selection
process
rather
than
by
default.
Existing
contaminants
that
do
not
make
it
on
to
the
list
could
be
incorporated
by
nomination
if
warranted.
AWWA
is
very
concerned
that
the
lack
of
a
robust
CCL
process
has
resulted
in
the
promulgation
of
a
placeholder
CCL
and,
in
doing
so,
the
agency
has
set
an
unacceptable
precedent,
of
rolling
over
contaminants
from
a
previous
CCL.
AWWA
recommends
EPA
evaluate
whether
available
information
actually
suggests
that
inclusion
of
all
the
remaining
CCL1
contaminants
on
CCL
2
targets
drinking
water
contaminants
that
pose
the
most
significant
potential
public
health
concerns.
AWWA
expects
that
if
EPA
were
to
evaluate
the
data
currently
available,
at
least
some
contaminants
currently
included
in
CCL1
would
not
be
listed
on
CCL
2.
The
agency's
current
approach
may
result
in
misdirection
of
scarce
research
funds
for
the
next
six
years,
not
only
by
the
agency
but
also
by
others
that
look
to
the
agency
for
guidance
on
research
priorities.
This
approach
may
also
mislead
drinking
water
utilities
as
they
conduct
monitoring,
select
treatment
processes,
and
make
other
capital
investments
and
operational
decisions
that
affect
water
quality.

Response:
See
the
response
to
the
comment
0017
part
4,
under
section
3.4.2
above.
28
3.0
Comments
on
Development
of
the
Draft
Drinking
Water
CCL
2
3.4
Other
3.4.3
Add
NDMA
and
enterotoxigenic
Escherichia
coli
(
E.
coli)
to
CCL
Docket
ID
­
Part
#

Comment:
0017
5
For
example,
we
recommend
that
five
of
the
chemicals
(
1,1,2,2­
tetrachloroethane,
1,1­
dichloropropene,
1,3­
dichloropropane,
1,3­
dichloropropene,
and
2,2,
dichloropropane)
that
were
carried
over
from
the
initial
CCL
to
the
CCL
2
be
reconsidered.
These
chemicals
were
monitored
as
part
of
the
Unregulated
Contaminant
Monitoring
Rule
(
UCMR)
monitoring
during
2001
through
2003.
In
the
state
of
Texas,
the
TCEQ
has
had
a
total
of
54,363
monitoring
results
for
these
organic
chemicals,
and
none
were
ever
detected.

Response:
See
the
response
to
the
comment
0017
part
4,
under
section
3.4.2
above.

Docket
ID
­
Part
#

Comment:
0018
5
3.
AMWA
suggests
EPA
add
N­
nitrosodimethylamine
(
NDMA)
to
the
CCL.
Research
has
shown
NDMA
is
a
disinfection
by­
product
of
chloramination.
As
more
systems
turn
to
chloramination
in
anticipation
of
the
Stage
2
Microbial
and
Disinfection
Byproducts
(
M/
DBP)
Rules,
understanding
more
about
this
"
new"
DBP
is
critical,
since
its
occurrence
in
drinking
water
may
increase.
Additionally,
EPA
classifies
NDMA
as
a
probable
human
carcinogen.

Therefore,
listing
NDMA
on
the
CCL
would
fit
the
SDWA's
criteria
of
being
a
contaminant
that
has
an
adverse
effect
on
public
health,
and
is
likely
to
occur
in
drinking
water.
Having
NDMA
on
the
CCL
will
enable
EPA
to
then
justify
further
research
on
this
contaminant.

Response:
There
is
already
a
substantive
body
of
health
effects
research
that
the
Agency
has
relied
upon
to
classify
NDMA
as
a
"
probable
human
carcinogen"
(
USEPA,
1993).
The
key
information
gap
for
this
contaminant
relates
to
occurrence
in
public
water
system
distribution
systems.
Some
initial
research
has
been
conducted
in
this
area
and
the
Agency
plans
to
collect
more
comprehensive
occurrence
information
as
part
of
the
upcoming
national
survey
of
key
unregulated
contaminants
under
section
1445(
a)(
2).
EPA
will
consider
NDMA
for
listing
as
part
of
the
CCL
3
process,
which
will
be
a
comprehensive
reevaluation
of
the
contaminants
considered
for
the
CCL.

Docket
ID
­
Part
#

Comment:
0019/
20
31
AWWA
recommends
that
the
chemical
contaminant
N­
nitrosodimethylamine
(
NDMA)
and
the
microbial
contaminant
enterotoxigenic
E.
coli
be
included
on
CCL
2.
Both
contaminants
were
considered
in
developing
CCL1,
but
were
not
listed.
Substantial
NDMA
research
has
been
conducted
since
1998
and
evidence
exists
for
its
occurrence
in
U.
S.
drinking
waters
at
29
levels
of
health
concern.
NDMA
is
certainly
an
emerging
issue
and
is
precisely
the
type
of
contaminant
the
CCL
process
was
intended
to
capture.
Indeed,
EPA
has
already
allocated
substantial
resources
to
NDMA
analytical
methods
development
under
the
aegis
of
the
CCL
(
EIMS
entry
#'
s
18339,
62563).
Similarly,
listing
of
enterotoxigenic
E.
coli
is
appropriate
at
this
time
and
would
be
consistent
with
the
NDWAC
Work
Group's
recommendation
that
microbes
known
to
have
caused
waterborne
disease
outbreaks
receive
serious
consideration
for
placement
on
the
CCL.

Response:
See
the
responses
to
comments
0018
part
5,
under
section
3.4.3
and
0019/
20
part
32,
under
section
3.4.3.

Docket
ID
­
Part
#

Comment:
0019/
20
32
AWWA
recommended
that
enterotoxigenic
Escherichia
coli
(
E.
coli)
be
considered
for
CCL
2.
If
the
agency
rejects
inclusion
of
enterotoxigenic
E.
coli
it
will
repeat
the
inconsistent
decision
logic
underlying
CCL1
(
i.
e.,
some
contaminants
were
excluded
from
CCL
based
on
susceptibility
to
drinking
water
treatment
while
others
were
not)
identified
in
AWWA's
comments
on
the
CCL1
proposal.

Response:
EPA
will
be
considering
this
microbe
as
part
of
the
revised
and
expanded
CCL
3
review
process.
The
Agency
believes
that
this
will
be
a
more
appropriate
and
effective
approach
for
evaluating
this
bacteria
in
comparison
to
a
wide
range
of
other
microbes
that
will
be
considered
under
the
broader
analytical
approach
recommended
by
the
NRC
and
NDWAC.

Docket
ID
­
Part
#

Comment:
0019/
20
33
The
available
information
suggest
that
we
have
some
indication
of
health
effects
and
that
we
know
that
E.
coli
survives
in
water
and
that
there
has
been
an
outbreak
that
is
likely
to
be
caused
by
ingesting
drinking
water.
Therefore
enterotoxigenic
E.
coli
should
be
added
to
the
CCL.
AWWA
requests
that
the
agency
clearly
articulate
why
enterotoxigenic
E.
coli
is
not
added
to
CCL
2
if
the
CCL
2
list
is
finalized
without
its
inclusion.

Response:
See
the
response
to
the
comment
0019/
0020
part
32,
under
section
3.4.3
above.
30
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.1
Comments
on
Screening
of
the
Universe
of
Contaminants
4.1.2
Comments
Critical
of
the
NRC's
Approach
for
Screening
the
Universe
of
Contaminants
Docket
ID
­
Part
#

Comment:
0018
8
EPA
should
maintain
a
clear
focus
on
contaminants
that
are
likely
to
occur
in
drinking
water
and
likely
to
cause
a
public
health
concern.
For
this
reason,
AMWA
believes
it
is
counterproductive
to
consider
the
entire
universe
of
existing
chemicals.
Because
of
tight
budgets
and
limited
research
dollars,
EPA
should
focus
research
on
substances
where
information
is
available
and
quality
of
data
is
high.

Response:
EPA
agrees
that
the
CCL
process,
as
specified
by
the
SDWA,
should
consider
those
contaminants
with
the
potential
to
occur
in
drinking
water
and
those
with
the
potential
to
cause
adverse
health
effects.
EPA
is
currently
evaluating
data
sources
to
identify
contaminants
for
consideration
in
the
next
CCL.
As
the
Agency
develops
the
next
CCL
and
evaluates
the
approaches
recommended
by
the
National
Academy
of
Sciences
and
the
National
Drinking
Water
Advisory
Council
it
will
also
consider
the
availability
of
information
and
the
quality
of
that
information.

Docket
ID
­
Part
#

Comment:
0019/
20
60/
61
How
contaminants
are
evaluated
and
chosen
to
move
from
one
category
to
another
(
e.
g.,
Universe
to
PCCL)
is
very
complicated.
The
approaches
taken
are
critical
since
the
contaminants
that
are
chosen
for
the
PCCL
and
therefore,
the
CCL,
will
be
strongly
influenced
by
the
algorithms
and
methods
chosen.
So
while
the
NRC
approach
is
attractive
and
well
thought
out,
it
is
still
a
theoretical
approach
that
is
not
ready
for
application
without
a
substantial
investment
of
time
and
resources.
Moreover,
given
the
agency's
limited
resources
and
compressed
time
frame,
it
is
reasonable
to
question
the
value­
added
nature
of
the
PCCL
concept
in
near­
term
iterations
of
the
CCL
process.

The
NRC
paradigm
should
be
established
as
an
ultimate
objective
for
the
evolution
of
the
CCL
process.
EPA
should
include
the
NRC's
three
steps
(
i.
e.,
universe
to
PCCL
to
CCL),
but
the
agency
should
better
define
the
process
to
describe
all
the
interim
steps,
which
will
be
required
to
actually
implement
the
CCL
process.

Response:
EPA
is
evaluating
and
testing
the
National
Research
Council's
approach,
as
refined
in
the
National
Drinking
Water
Advisory
Council
recommendations
(
2204).
The
Agency
will
consider
this
comment
during
those
evaluations.
Many
EPA
programs
rely
on
screening
techniques
to
identify
priorities.
EPA
is
currently
evaluating
alternative
approaches
for
screening
criteria
in
addition
to
those
recommended
by
the
National
Drinking
Water
Advisory
Council
and
will
seek
external
input
on
these
evaluations.

EPA
is
currently
in
the
process
of
identifying
and
describing
the
interim
steps
to
develop
the
CCL.
As
described
in
the
National
Drinking
Water
Advisory
Council
recommendations
31
these
steps
may
include
evaluating
alternatives,
seeking
expert
input
and
review,
and
documenting
each
step
of
the
CCL
selection
process.
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.2
Comments
on
the
Approach
for
Compiling
the
Preliminary
CCL
(
PCCL)
4.2.2
Comments
Critical
of
the
NRC's
Approach
for
Compiling
the
PCCL
Docket
ID
­
Part
#

Comment:
0019/
20
44
AWWA
does
not
believe
that
the
NRC
recommendation
of
going
from
a
universe
to
a
PCCL
is
of
any
particular
use
at
this
time.
NRC
recommends
this
winnowing
to
the
PCCL
no
matter
how
the
CCL
is
developed.

Response:
See
the
response
to
the
comment
0019/
20
part
60
and
61,
under
section
4.1.2.
32
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.3
Comments
on
the
Approach
for
Contaminant
Selection
from
the
PCCL
to
the
CCL
4.3.2
Comments
Critical
of
the
NRC's
Approach
for
Contaminant
Selection
from
the
PCCL
to
the
CCL
Docket
ID
­
Part
#

Comment:
0024
2
Now
that
the
EPA
has
experience
with
the
first
CCL
and
monitoring
data
from
the
Unregulated
Contaminant
Monitoring
Rule,
we
recommend
that
the
EPA
perform
a
sensitivity
analysis
to
refine
its
occurrence
screens
(
found
in
a
water
system
serving
a
population
of
100,000
or
more,
found
in
at
least
10
small
public
water
systems,
TRI
release
estimates,
production
volume,
etc.)
to
eliminate
potential
contaminants
that
are
not
"
known
or
anticipated
to
occur
in
public
water
systems
at
a
level
of
public
health
concern."

Response:
In
addition
to
evaluating
the
National
Academy
of
Sciences
and
National
Drinking
Water
Advisory
Council
recommendations
the
Agency
will
perform
sensitivity
analyses
in
addition
to
other
analytical
tools
to
refine
occurrence
screens
for
the
CCL
selection
process.
33
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.4
Comments
on
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
4.4.1
Comments
Supporting
the
NRC's
Approach
of
Using
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
Docket
ID
­
Part
#

Comment:
0017
7
The
virulence
factor
activity
relationship
(
VFAR)
appears
to
be
a
potentially
useful
tool
for
future
CCLs.

Response:
EPA
agrees
and
is
evaluating
this
tool
for
future
CCL
development.
34
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.4
Comments
on
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
4.4.2
Comments
Critical
of
the
NRC's
Approach
of
Using
the
Virulence
Factor
Activity
Relationships
(
VFARs)
for
Assessing
Emerging
Waterborne
Pathogens
Docket
ID
­
Part
#

Comment:
0017
8/
9
However,
while
gene
mapping
is
scientifically
sound,
it
may
not
offer
practical
solutions
to
immediate
concerns
regarding
waterborne
disease.
In
addition,
it
is
widely
recognized
that
this
particular
tool,
while
promising,
still
needs
further
development
and
testing
before
incorporation
into
the
CCL
process.

We
recommend
that
the
EPA
consider
practical
methods
for
improving
the
correct,
timely
identification
of
actual
waterborne
illness.

Response:
EPA
agrees
that
gene
mapping
and
the
virulence
factor
activity
relationship
concepts
will
require
further
development
and
testing
before
it
can
be
incorporated
into
the
CCL
process.
The
National
Drinking
Water
Advisory
Council,
which
noted
that
these
technologies
may
not
be
available
for
the
next
CCL,
provided
recommendations
that
use
currently
available
data
to
select
microbial
contaminants
for
the
CCL.
The
Agency
has
met
with
experts
in
microbial
disease
and
genomics
in
workshops
and
at
drinking
water
conferences
to
discuss
how
to
include
genomics
data
in
the
future
CCLs.
The
Agency
has
also
formed
intra­
agency
workgroups
to
develop
guidelines
on
the
use
of
genomic
data
in
the
future.
35
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.5
Other
Docket
ID
­
Part
#

Comment:
0018
9
EPA
has
also
obtained
data
about
potential
drinking
water
exposure
to
pesticides
regulated
under
the
Food
Quality
Protection
Act
(
FQPA).
This
information
could
be
used
in
an
initial
screening
of
substances
for
the
CCL.

Response:
EPA's
Office
of
Ground
Water
and
Drinking
Water
is
seeking
the
input
of
other
offices
within
EPA
to
ensure
that
sources
of
available
data
on
drinking
water
occurrence
are
used
in
the
CCL
selection
process.

Docket
ID
­
Part
#

Comment:
0018
10
OGWDW
should
work
with
OPPT
to
ensure
that
the
screening
protocol
includes
a
drinking
water
exposure
component
and
use
this
information
to
inform
future
CCLs.

Response:
EPA's
Office
of
Ground
Water
and
Drinking
Water
is
seeking
the
input
of
other
offices
within
EPA
to
ensure
that
sources
of
available
data
on
drinking
water
occurrence
are
used
in
the
CCL
selection
process.

Docket
ID
­
Part
#

Comment:
0018
11
On
the
microbial
side,
EPA
should
focus
on
microbial
agents
implicated
in
disease
by
consulting
with
CDC
and
public
health
agencies
that
have
public
health
surveillance
programs
for
waterborne
disease.

Response:
EPA
anticipates
working
with
agencies,
like
the
CDC,
to
collect
public
health
and
surveillance
information
to
identify
pathogens
associated
with
water
borne
disease
for
consideration
in
the
CCL
process.

Docket
ID
­
Part
#

Comment:
0018
12
Because
contaminants
on
the
CCL
are
placed
there
to
help
inform
research
and
to
be
considered
for
regulatory
determination
under
the
SDWA,
EPA
has
at
least
two
options
on
how
to
address
this
issue:

1)
Obtain
the
missing
data
so
that
the
contaminants
can
be
screened
for
inclusion
on
the
CCL.
(
This,
however,
may
not
be
the
best
use
of
limited
resources).
36
2)
Defer
the
decision
on
the
contaminant
until
such
data
is
available
from
other
sources,
unless
there
is
a
strong
indication
from
the
known
parameters
about
the
contaminant
that
is
likely
to
pose
a
health
concern
in
drinking
water.

Response:
EPA
plans
to
explore
alternative
approaches
for
addressing
contaminants
with
missing
data
in
selecting
future
CCL
candidates.
37
4.0
Comments
on
the
NRC's
Recommended
Approach
for
Developing
Future
CCLs
4.5
Other
4.5.1
CCL
Transparency
Docket
ID
­
Part
#

Comment:
0018
2
2.
AMWA
supports
the
need
for
a
transparent
process.
AMWA
agrees
that
the
CCL
classification
process
should
be
transparent
so
that
both
the
regulated
community
and
the
public
can
understand
it.

Response:
The
Agency
agrees
with
the
commenter
that
the
CCL
process
should
be
understandable
to
the
regulated
community
and
interested
stakeholders.
The
Agency
anticipates
developing
approaches
to
clearly
communicate
the
how
the
CCL
process
selects
contaminants.

Docket
ID
­
Part
#

Comment:
0018
3/
4
AMWA
believes
expert
judgement
is
as
critical
to
the
listing
process
as
it
is
to
its
transparency.

AMWA
also
supports
the
NDWAC
work
group's
recommendations
that
external
experts
should
be
involved
in
evaluating
the
CCL
classification
process
in
several
key
areas
including:

°
The
identification
of
screening
criteria;
°
The
assessment
of
an
algorithm's
training
data
set;
°
The
evaluation
of
a
prioritized
list
of
contaminants;
°
The
data
quality
review;
and
°
The
review
of
the
proposed
CCL,
prior
to
its
publication
in
the
Federal
Register.

Response:
EPA
agrees
that
expert
judgment
is
important
component
to
the
CCL
selection
process
and
is
evaluating
approaches
to
incorporate
and
document
expert
input
and
review
in
developing
the
CCL
process.
We
will
consider
these
ideas
as
we
develop
the
CCL
process.

Docket
ID
­
Part
#

Comment:
0019/
20
11
Transparency
is
a
critical
aspect
of
the
CCL
process
and
maintaining
transparency
is
of
paramount
concern
for
those
involved
in
putting
forth
recommendations
for
improving
the
process.
However,
the
agency
perspective
on
the
NRC
report
appears
to
be
based
on
an
underlying
assumption
that
decisions
based
on
expert
judgment
are
not
transparent.
This
assumption
has
driven
the
CCL
process
toward
automation
and
use
of
sophisticated
tools
that
are
not
necessarily
valid.
AWWA
believes
that
the
automation
and
use
of
sophisticated
computer
models,
programs,
etc.,
does
not
change
the
fact
that
underlying
the
entire
process
is
expert
judgement.
In
fact,
AWWA
believes
that
the
utility
of
the
process
proposed
by
NRC
is
as
a
means
of
applying
data
processing
tools
to
screen
a
large
number
of
contaminants
and
38
not
in
imparting
transparency.

All
work
done
on
the
evaluation
of
methods
for
creating
the
CCL
reach
the
conclusion
that
expert
judgment
will
be
a
critical
part
of
any
CCL
development
(
e.
g.,
NRC
2001,
NDWAC
2004).
AWWA
believes
that
the
CCL
process
should
be
characterized
as
an
expert
process.
Expert
judgment
does
not
preclude
transparency.
In
fact,
an
expert
process,
especially
one
supported
by
good
documentation
and
decision
support
systems,
can
be
more
transparent
than
an
algorithm
approach
where
considerable
expert
judgment
is
buried
deep
within.

To
maintain
transparency,
the
role
of
expert
judgment
in
the
process
needs
to
be
explicitly
defined
both
relative
to
where
and
when
the
experts
will
intervene
and
in
which
processes.
Explicit
protocols
and
rules
for
the
expert
selection,
deliberations,
and
decision­
making
need
to
be
clearly
documented.
The
transparency
of
any
expert
judgement
process
is
only
as
clear
as
the
quality
of
the
documentation
supplied
regarding
the
underlying
expert
judgements
and
the
way
the
algorithms
have
been
developed
to
support
that
expert
judgement.
Rules
for
the
experts
will
help
in
transparency
and
in
improving
the
reproducibility
of
the
process.

Response:
EPA
agrees
that
transparency
and
expert
judgment
are
critical
components
of
the
CCL
selection
process.
Any
process
implemented
for
selecting
the
CCL
will
incorporate
both
at
each
step.
The
process
will
be
documented,
and
the
documentation
available
for
public
scrutiny.

Docket
ID
­
Part
#

Comment:
0019/
20
37
It
is
important
that
the
agency
realize
that
expert
processes
can
be
very
transparent,
and
the
perception
that
the
CCL1
process
was
not
transparent
is
not
a
failing
of
expert
processes,
but
may
have
been
a
failing
of
the
CCL1
process
as
implemented.
The
NRC
report
on
which
the
NDWAC
Work
Group
CCL
process
recommendation
is
based
appears
to
AWWA
to
reflect
an
over­
reaction
to
the
perceived
lack
of
transparency
in
the
CCL1
process.

Response:
EPA
believes
that
the
NRC
and
NDWAC
recommended
processes
are
indeed
expert
processes,
but
are
structured
to
allow
broader
consideration
of
potential
drinking
water
contaminants.
Any
process
for
CCL
selection
will
include
experts,
and
will
be
made
transparent.

Docket
ID
­
Part
#

Comment:
0019/
20
38/
39
The
CCL
process
should
include
multiple
mechanisms
to
actively
engage
interested
parties
and
experts
with
information
needed
in
the
CCL
process.

Some
mechanisms
include:

A.
Maintaining
an
active
CCL
process
that
is
a
routine
component
of
Office
of
Water
activity,
rather
than
a
periodic
(
i.
e.,
once
every
5
years)
burst
of
activity.
B.
Active
surveillance
of
the
peer­
reviewed
literature.
As
part
of
its
on­
going
work,
EPA
OGWDW
should
undertake
regular
surveillance
of
appropriate
literature
to
monitor
new
39
contaminants,
new
methods,
and
new
health
effects
data.
C.
Involvement
in
ongoing
symposia
and
profession
meeting
series
on
relevant
topics.

Response:
EPA
agrees
that
the
CCL
process
should
involve
interested
parties
and
experts.
The
Agency
considers
the
CCL
process
an
integral
component
of
its
activities
and
actively
performs
literature
reviews,
sponsors
and
participates
in
forums
on
relevant
topics,
and
monitors
the
development
of
new
data
and
information.
While
the
result
appears
only
every
5
years,
activity
relating
to
CCL
development
and
analysis
is
part
of
EPA's
drinking
water
program
on
an
ongoing
basis.
EPA
is
evaluating
approaches
to
include
interested
parties
in
the
CCL
process.
The
formation
and
support
of
the
National
Drinking
Water
Advisory
Council
CCL
Classification
Process
Work
Group
is
one
example
of
EPA's
commitment
to
engaging
interested
parties
in
developing
the
CCL
process.
The
Agency
held
a
public
meeting
on
September
15,
2004
to
present
the
status
of
the
Regulatory
Determination
2
and
efforts
to
refine
the
CCL
selection
process.
The
Agency
anticipates
informing
and
seeking
the
input
of
interested
parties
as
the
development
of
the
CCL
process
progresses.
As
the
Agency
evaluates
the
National
Drinking
Water
Advisory
Council
Report
recommendations,
which
are
similar
to
the
commenters
concerns,
we
will
consider
approaches
to
improve
actively
engage
interested
parties.
40
5.0
Implementation
of
NRC's
Recommendations
5.2
Comments
on
the
Ongoing
Analysis
of
the
Classification
Approach
5.2.1
Organizing
and
Extracting
Data
5.2.1.1
Comments
Supporting
EPA's
Approach
for
Organizing
and
Extracting
Data
for
the
CCL
Universe
Docket
ID
­
Part
#

Comment:
0019/
20
55/
56
In
principle,
AWWA
agrees
with
the
workgroup's
perspective
as
excerpted.
AWWA
believes
that
the
data
quality
criteria
for
each
step
in
the
CCL
process
should
be
directed
by
the
objectives
of
the
process
overall
and
by
that
specific
step
in
the
CCL
process.

An
expert
workshop
would
be
one
way
to
explore
the
above
questions
in
a
timely
manner.
AWWA
is
interested
in
participating
in
ongoing
development
and
application
of
a
quality
system
for
the
CCL
process
that
will
not
eliminate
the
usefulness
of
all
available
data
but
will
still
insist
on
data
of
appropriate
quality
for
each
step
in
the
CCL
process.

Response:
The
Agency
agrees
that
the
types
of
information
and
data
need
to
be
described
and
documented
so
that
interested
parties
can
understand
how
they
are
used
in
the
CCL
process.
The
Agency
looks
forward
to
AWWA's
continued
interest
in
developing
the
CCL
process
and
more
specific
comments
on
data
of
appropriate
quality.
See
response
to
comment
0019/
20
part
10
under
section
3.1.4.1.

Docket
ID
­
Part
#

Comment:
0019/
20
57
EPA
should
identify
compilations
of
information
on
potential
contaminants.
These
compilations
should
be
evaluated
and
characterized.
If
they
contain
relevant
information
and
the
data
are
of
adequate
quality,
then
they
could
be
used
to
compile
the
CCL
universe
and
develop
data
needed
to
determine
contaminant
attributes.
EPA
initiated
such
an
effort
in
support
of
the
NDWAC
CCL
Work
Group
process.

Response:
EPA
continues
to
identify
and
evaluate
compilations
of
data
on
potential
contaminants
from
the
initial
efforts
conducted
during
the
National
Drinking
Water
Advisory
Council
CCL
CP
Work
Group
process.

Docket
ID
­
Part
#

Comment:
0019/
20
58
Some
potential
activities
EPA
could
pursue
that
could
be
effective
in
identifying
emerging
contaminants
include:

1.
Regular
review
of
toxic
release
data
to
identify
contaminants
not
previously
observed
or
being
released
in
large
quantities.
2.
Regular
review
of
chemical
production
data
bases
coupled
with
QSARs.
3.
Repeating
EPA's
1997
query
of
commercial
and
state
laboratories
that
conduct
environmental
monitoring
for
the
unregulated
contaminants
that
are
appearing
in
the
41
samples
they
process.
4.
Developing
a
network
of
academics
(
such
as
those
that
research
analytical
methods
development)
in
order
to
detect
new
contaminants
in
the
environment.
5.
Developing
a
process
for
regular
review
and
evaluation
of
clinical
data
perhaps
in
conjunction
with
CDC.

Response:
EPA
is
currently
evaluating
how
to
use
chemical
production
and
toxic
release
data
in
the
CCL
process.
The
additional
recommended
activities
are
also
being
assessed
as
on­
going
surveillance
activities
to
identify
contaminants
for
consideration
in
the
CCL
process.
As
surveillance
activities
are
developed
for
the
CCL
process
these
activities
will
be
considered
with
other
options
for
identifying
potential
contaminants.
42
5.0
Implementation
of
NRC's
Recommendations
5.2
Comments
on
the
Ongoing
Analysis
of
the
Classification
Approach
5.2.1
Organizing
and
Extracting
Data
5.2.1.2
Comments
Critical
of
EPA's
Approach
for
Organizing
and
Extracting
Data
for
the
CCL
Universe
Docket
ID
­
Part
#

Comment:
0017
10
In
addition,
we
believe
that
EPA
should
consider
existing
or
developing
risks,
rather
than
be
restricted
to
historical
lists
developed
in
the
initial
rule.

Response:
EPA
recognizes
that
it
is
important
to
identify
new
and
emerging
contaminants
as
part
of
the
CCL
selection
process.
The
Agency
is
evaluating
a
process
that
will
incorporate
the
nomination
of
contaminants
and
will
undertake
activities
to
enhance
surveillance
of
contaminants
for
future
CCLs.

Docket
ID
­
Part
#

Comment:
0019/
20
52
The
CCL
effort
should
access
existing
information
systems
from
EPA
and
from
other
federal
agencies.
Lists
of
recommended
data
sources
are
presented
below
relating
to
the
key
issue:
the
appropriate
data
to
be
used.
Data
is
the
foundation
of
the
process
and
existing
EPA
information
systems
do
not
currently
meet
the
needs
of
the
CCL
process.

This
following
list
contains
information
sources
that
could
be
extracted
in
an
automated
manner
(
The
list
is
in
alphabetical
order.).

°
ATSDR
CERCLA
Priority
List
°
ATSDR
Internet
HazDat
­
Site
Contaminant
Query
°
Carcinogenic
Potency
Project
°
ChemIDplus
­
Chemical
Identification
Plus
°
EAFUS
Database
­
Everything
Added
to
Food
in
the
United
States
°
EDPSD
­
Endocrine
Disruptor
Priority
Setting
Database
°
GRAS
­
Generally
Regarded
As
Safe
Substance
List
°
HPV
­
High
Production
Volume
Chemical
List
°
IARC
­
International
Agency
for
Research
on
Cancer
Monographs
°
ITER
Database
­
International
Toxicity
Estimates
for
Risk
°
JMPR
(
Joint
Meeting
On
Pesticide
Residues
­
Inventory
through
2002)
­
WHO,
FAO
°
Master
Summary
Table
for
HPV
Chemical
Hazard
Data
Availability
Study
°
National
Reconnaissance
of
Emerging
Contaminants
­
USGS
Toxic
Substances
°
Hydrology
Program
(
NREC)
°
National
Stream
Quality
Accounting
Network
(
NASQAN)
°
NCOD
­
National
Drinking
Water
Contaminant
Occurrence
Database
Unregulated
Contaminant
Monitoring
Rule
UCMR
°
Pesticides
Pilot
Monitoring
Program
­
USGS/
EPA
°
Risk
Assessment
Information
System
(
RAIS)
­
Department
of
Energy
°
Toxicity
Criteria
Database
­
California
Office
of
Environmental
Health
Hazard
Assessment
°
UCMR
­
Round
2
(
SDWIS/
FED)
­
Unregulated
Contaminant
Monitoring
43
Response:
EPA
is
in
the
process
of
evaluating
data
sources
for
possible
inclusion
in
the
CCL
process
but
disagrees
with
the
commenter
that
EPA
information
sources
do
not
meet
the
needs
of
the
CCL.
The
sources
AWWA
identified
will
be
considered
as
part
of
this
evaluation.

Docket
ID
­
Part
#

Comment:
0019/
20
59
The
exclusion
of
these
data
or
the
demotion
of
these
data
to
a
secondary
source
will
result
in
a
loss
of
a
great
deal
of
useful
important
information.
EPA
needs
to
address
how
the
text
data
and
information
will
be
monitored
and
incorporated
into
the
process.

Response:
EPA
is
currently
evaluating
options
for
including
text
data
and
information
into
the
CCL
process
and
will
consider
these
comments
in
developing
future
CCLs.
44
5.0
Implementation
of
NRC's
Recommendations
5.2
Comments
on
the
Ongoing
Analysis
of
the
Classification
Approach
5.2.3
Classifying
Contaminants
from
the
PCCL
to
the
CCL
5.2.3.1
Comments
Supporting
the
Ongoing
Approach
Used
for
Classifying
Contaminants
from
the
PCCL
to
the
CCL
Docket
ID
­
Part
#

Comment:
0019/
20
45
Experts
need
to
be
involved
in
developing
the
training
data
set,
and
then,
once
the
training
set
is
chosen,
experts
need
to
be
involved
in
scoring
the
attributes
for
the
training
data
set.

Response:
EPA
recognizes
the
need
to
involve
experts
in
the
CCL
process.
The
Agency
will
consider
approaches
to
incorporate
expert
input
during
the
selection
of
contaminants
for
the
CCL
from
the
preliminary
PCCL
as
noted
by
the
commenter.

Docket
ID
­
Part
#

Comment:
0019/
20
46
In
developing
the
algorithm,
it
should
reflect
and
document
the
same
logical
process
experts
would
use
if
an
expert
process
were
employed.
To
achieve
this
objective,
development
of
the
algorithm
will
need
to
reflect
an
ongoing
effort
to
capture
and
mirror
the
decision­
making
logic
of
an
expert
process.

Once
an
algorithm
is
given
parameters
and
initial
runs
appear
adequate
to
the
technicians
working
on
this
portion
of
the
analysis,
experts
should
be
involved
in
evaluating
the
classification
abilities
of
the
algorithm.

Response:
The
Agency
will
consider
this
comment
as
it
evaluates
the
National
Drinking
Water
Advisory
Council
recommendations
on
how
to
move
from
a
preliminary
CCL
and
select
contaminants
for
the
CCL.
As
the
Agency
develops
the
CCL
process
there
will
be
a
need
for
expert
involvement.
EPA
is
considering
approaches
such
as
public
meetings
and
expert
workshops
to
facilitate
expert
input.

Docket
ID
­
Part
#

Comment:
0019/
20
48
AWWA
recommends
using
a
Delphi­
like
process
and
then
comparing
the
expert
decision
for
each
test
contaminant
with
the
decision
from
the
algorithm.

Response:
EPA
will
consider
this
approach
as
it
develops
the
CCL
process,
particularly
in
the
selection
of
CCL
contaminants
from
a
preliminary
CCL.

Docket
ID
­
Part
#
45
Comment:
0019/
20
49
Once
the
process
and
algorithms
are
validated,
experts
still
need
to
be
involved
in
evaluation
of
the
draft
list
emerging
from
the
CCL
classification
algorithm.

Response:
EPA
agrees
that
expert
involvement
is
a
necessary
component
of
any
proposed
CCL
process,
and
plans
to
involve
experts
at
key
milestones
in
the
CCL
development
process.

Docket
ID
­
Part
#

Comment:
0019/
20
51
The
NDWAC
CCL
Workgroup
included
a
process
for
microbial
contaminants
that
is
a
very
pragmatic
approach
to
filtering
and
identifying
pathogens
for
the
CCL.
It
involves
specific
expert
judgments
that
are
applied
in
a
systematic
manner.
This
approach
emerged
from
a
careful
review
of
the
objectives
and
realities
of
the
available
data.
AWWA
believes
this
is
an
appropriate
direction
and
a
parallel
approach
for
chemical
contaminants
could
be
developed
and
would,
if
properly
developed,
provide
the
necessary
framework
for
developing
future
iterations
of
the
CCL
chemical
contaminant
selection
process.

Response:
EPA
agrees
that
the
microbial
approach
to
identify
CCL
microorganisms
recommended
by
the
National
Drinking
water
Advisory
Council
Differs
from
the
National
Academy
of
Sciences
recommendations.
As
the
Agency
evaluates
the
CCL
process
it
will
consider
how
a
parallel
approach
for
chemical
contaminants
might
be
developed.
One
area
of
divergence,
however,
is
that
the
nature
and
volume
of
the
available
information
for
chemical
and
microbial
contaminants
are
vastly
different.
For
microbes,
there
are
few
compilations
of
data
that
identify
the
occurrence
and
effects
of
microbes,
while
for
chemicals
there
are
numerous
sources.
While
the
National
Drinking
Water
Advisory
Council
recommended
that
the
approach
for
microbes
be
based
on
the
nature
and
type
of
data
available
it
made
a
similar
recommendation
for
chemical
contaminants
and
recognized
that
those
differences
would
allow
a
process
to
select
chemical
contaminants
that
more
closely
follows
the
National
Academy
of
Sciences
recommendations.

Docket
ID
­
Part
#

Comment:
0019/
20
64
Once
the
attribute
is
scored,
it
is
difficult
to
factor
in
the
effects
of
using
different
underlying
data
elements.
Therefore,
EPA
needs
to
establish
an
understanding
of
the
attributes,
their
data
elements
and
the
methods
for
scoring
the
attributes.
This
clarification
should
also
evaluate
the
effects
of
using
different
data
elements
to
score
the
attributes.

Response:
EPA
agrees
that
evaluation
of
input
data
and
approaches
for
attribute
scoring
are
an
important
components
of
the
CCL
classification
process
recommendations.
The
Agency
will
consider
a
range
of
analyses
with
available
data
to
evaluate
attribute
scoring
approaches
as
well
as
alternative
approaches
to
characterize
and
evaluate
contaminants.

Docket
ID
­
Part
#
46
Comment:
0019/
20
65
In
developing
the
CCL
process
it
is
essential
that
EPA
identify
what
critical
information
is
necessary
to
adequately
characterize
occurrence
and
health
effects
for
any
contaminant.
What
this
critical
information
is
should
be
determined
through
expert
processes,
and
reflect
(
1)
information
required
by
experts
evaluating
contaminants
for
inclusion
on
the
CCL
and
(
2)
appropriate
for
the
specific
analytical
tools
the
agency
uses
to
produce
the
CCL
(
i.
e.,
the
screening
and
classification
algorithms).

Response:
EPA
will
consider
this
recommendation
as
it
evaluates
and
refines
the
CCL
process.
The
Agency
is
evaluating
the
nature
and
types
of
information
available
to
characterize
occurrence
and
health
effects.
As
the
evaluations
proceed
the
Agency
will
seek
expert
input
on
the
evaluations
and
the
information
identified
by
those
evaluations.

Docket
ID
­
Part
#

Comment:
0019/
20
66
EPA
can
still
focus
resources
on
generating
the
data
missing
for
any
contaminants.
It
can
then
evaluate
them
in
future
CCL
efforts
or
nominated
them
for
immediate
consideration.

Response:
EPA
is
considering
options
for
addressing
missing
data
for
potential
drinking
water
contaminants.
47
5.0
Implementation
of
NRC's
Recommendations
5.2
Comments
on
the
Ongoing
Analysis
of
the
Classification
Approach
5.2.3
Classifying
Contaminants
from
the
PCCL
to
the
CCL
5.2.3.2
Comments
Critical
of
the
Ongoing
Approach
Used
for
Classifying
Contaminants
from
the
PCCL
to
the
CCL
Docket
ID
­
Part
#

Comment:
0019/
20
63
AWWA
proposes
a
simplified
approach
that
will
eliminate
some
of
the
major
complications
associated
with
the
NRC
three­
step
(
i.
e.,
Universe
to
PCCL
to
CCL),
five­
attribute
CCL
process.
For
each
contaminant
that
is
included
in
the
PCCL,
the
existing
attributes
should
be
combined
along
two
simple
axises:
health
effects
and
occurrence
(
or
exposure).

Response:
EPA
is
evaluating
the
feasibility
of
implementing
the
National
Drinking
Water
Advisory
Council
recommendations
on
the
National
Academy
of
Sciences'
three­
step
approach.
It
is
important
to
note
that
the
National
Drinking
Water
Advisory
Council
also
recommended
that
EPA
consider
approaches
that
may
be
appropriate
for
the
next
CCL
and
modify
or
refine
the
process
for
future
CCLs
as
information
is
garnered
in
successive
CCLs.
As
the
Agency
develops
the
CCL
process
for
the
next
publication
it
will
consider
the
commenters
proposal.
48
5.0
Implementation
of
NRC's
Recommendations
5.2
Comments
on
the
Ongoing
Analysis
of
the
Classification
Approach
5.2.4
The
VFAR
Concept
and
Classifying
Microorganisms
5.2.4.2
Comments
Critical
of
the
Use
of
the
VFAR
concept
for
Classifying
Microorganisms
Docket
ID
­
Part
#

Comment:
0019/
20
12/
13/
14
Virulence
factor
activity
relationships
(
VFARs)
are
proposed
as
an
alternative
to
identifying
and
characterizing
microbiological
contaminants
for
which
there
is
little
information.
Molecular
tools
including
genomics,
microarray
technologies,
and
VFARs
are
certainly
powerful
tools
that
should
be
developed
with
the
CCL
in
mind.
However,
although
these
are
advanced
technologies,
their
application
to
environmental
samples
is
not
sufficiently
advanced
to
have
an
immediate
impact
on
the
CCL
process.
The
disproportionate
emphasis
on
VFARs
in
the
proposal
is
a
cause
for
concern
and
suggests
that
the
agency
is
pinning
its
hopes
on
the
latest
novel
technology.
The
rapidly
evolving
nature
of
this
technical
field
and
the
apparent
high
importance
placed
on
the
VFAR
approach
by
the
EPA
warrants
a
somewhat
detailed
and
technical
response.
The
use
of
phrases
such
as
"
sophisticated
computer
software
program"
and
lack
of
details
explaining
exactly
how
technologies
will
be
applied
suggests
that
the
agency
may
have
unrealistic
expectations
of
what
can
be
achieved
with
emerging
technologies.

Despite
the
extensive
discussion
of
VFAR
in
the
Federal
Register
notice,
the
actual
mechanisms
by
which
VFARs,
microarrays,
and
genomic
technologies
will
be
applied
to
the
CCL
process
are
not
clear.
The
agency
recognizes
that
the
use
of
the
VFAR
approach
to
identify
potential
waterborne
pathogens
"
would
require
a
multi­
year
commitment
and
significant
cooperation
and
collaboration
by
EPA
and
other
participating
organizations."
However,
by
placing
such
a
prominent
focus
on
this
technology
in
the
current
notice,
the
agency
will
precipitate
a
wholesale
dive
into
the
technology
by
researchers
looking
for
the
next
novelty.
This
will
result
in
a
series
of
reports
and
papers
that
demonstrate
the
utility
of
microarrays
to
detect
a
few
select
pathogens,
or
to
discriminate
between
strains
of
a
particular
pathogen
in
the
laboratory,
but
with
no
clear
application
to
the
CCL
process.
As
with
PCR,
the
industry
may
be
presented
with
a
wonderful
detection
technology
with
great
sensitivity,
specificity,
high
throughput,
etc,
but
no
consistent
way
to
apply
it
to
environmental
samples.
PCR
is
still
not
in
widespread
use
for
environmental
samples
because
no
effort
has
been
expended
to
overcome
problems
of
inhibition,
sample
matrix
effects,
very
low
concentrations
of
genomic
material
in
very
large
sample
volumes,
techniques
for
sample­
size
reduction,
applicable
extraction
methods,
etc.

Many
of
the
problems
that
have
plagued
the
application
of
PCR
to
drinking
water
will
also
have
a
significant
negative
impact
on
the
use
of
VFARs
and
microarrays.
There
needs
to
be
a
greater
effort
on
developing
methods
to
overcome
sample
processing
problems
for
the
application
of
molecular
methods
to
environmental
samples,
particularly
water
samples.
For
example,
recently
completed
Water
Environment
Research
Foundation
(
WERF)­
funded
projects
addressed
sample
processing
but
did
not
overcome
all
problems
(
Higgins,
DiGiovanni,
and
Harwood,
2002).
Molecular
tools
have
proved
very
useful
in
the
clinical
and
food
industries
where
the
challenge
is
to
detect
relatively
large
numbers
of
pathogens
in
relatively
small
sample
volumes
of
tissue,
fluid,
or
food
product.
However,
the
application
of
such
tools
within
the
drinking
water
field
presents
the
converse
situation
­­
typically
very
low
concentrations
of
target
organisms
in
very
large
sample
volumes
(
10
 
1,000
L
or
greater).
49
Response:
EPA's
agrees
with
the
commenter
that
molecular
and
genomic
tools
are
powerful
and
that
approach
may
offer
significant
opportunities
for
identifying
emerging
microbial
contaminants
in
the
future.
However,
it
may
not
be
sufficiently
developed
in
time
for
the
next
CCL.
The
discussion
of
the
process
of
bioinformatics
research
was
to
inform
the
public
of
the
steps
in
that
process,
not
to
suggest
that
the
agency
plans
to
focus
solely
on
virulence
factor
activity
relationships
research
to
the
exclusion
of
alternative
microbial
contaminant
approaches
that
can
be
implemented
in
the
short
term.
Preliminary
research
on
virulence
factor
activity
relationships
conducted
during
the
National
Drinking
Water
Advisory
Council
Contaminants
Candidate
List
Classification
Process
Workgroup
suggested
there
may
be
complexities
in
developing
virulence
factor
activity
relationships
that
were
not
considered
by
the
National
Academy
of
Sciences
in
their
recommendations.
EPA
will
consider
the
commenters
suggestions
as
the
new
information
on
genomic
and
molecular
techniques
becomes
available
for
future
application
to
microbial
drinking
water
contaminant
identification,
but
recognizes
they
may
be
well
enough
developed
for
the
short
term.

Docket
ID
­
Part
#

Comment:
0019/
20
15
As
stated
above,
there
is
a
disproportionate
emphasis
on
VFAR
technology
within
this
notice,
but
what
happens
if
the
VFAR
approach
does
not
bear
fruit?
What
parallel
approaches
will
be
pursued
along
with
VFARs?
In
the
next
to
last
paragraph
of
the
proposal,
EPA
states
that
it
will
explore
alternatives
such
as
"
an
approach
that
would
construct
a
microbiological
universe,
define
microbiological
attributes,
and
score
the
attributes."
This
does
not
give
any
indication
at
all
of
what
this
alternative
approach
might
actually
be
and
does
not
inspire
confidence
that
the
agency
has
actually
thought
through
alternatives
to
VFARs.

Response:
EPA
has
been
working
toward
an
alternative
approach
for
selecting
microbial
contaminants
for
the
next
CCL
based
on
the
National
Drinking
Water
Advisory
Council
recommendations.
Their
recommendation
parallels
the
process
for
selecting
chemical
contaminants.
The
process
may
include
identification
of
organisms
and
defining
a
microbial
CCL
universe
of
pathogens,
criteria
for
screening
the
microbial
universe
to
a
PCCL
based
on
the
organism
ability
to
transmit
disease
via
water,
and
prioritizing
PCCL
contaminants
for
consideration
for
the
next
CCL
based
on
the
occurrence
and
adverse
health
effects.
As
the
Agency
continues
to
evaluate
this
approach
it
will
consider
the
commenters
suggestions
and
questions.

Docket
ID
­
Part
#

Comment:
0019/
20
16
The
NRC
also
recommended
the
exploration
of
microarray­
based
technologies
and
these
technologies
should
play
a
pivotal
role
in
any
future
VFAR
approach.
Consequently,
the
agency
should
strive
for
accurate
descriptions
of
technologies
in
public
documents.
Microarrays
do
not
involve
placing
"
tiny
cells"
on
glass
wafers.
A
more
appropriate
description
may
be
that
microarrays
comprise
a
large
number
of
nucleic
acid
probes
attached
to
small
glass
or
nylon
wafers
(
slides),
and
that
these
microarrays
can
range
in
capacity
from
a
few
hundred
probes
per
array
to
many
thousands
per
array.
There
are
some
examples
of
the
use
of
microarrays
for
environmental
and
water­
related
applications
(
Straub
et
al.,
2002;
Call
et
al.,
2003).
Some
biotechnology
companies
claim
their
microarrays
can
detect
and
identify
50
thousands
of
pathogens
in
a
single
reaction
(
www.
tekes.
fi),
but
the
actual
utility
for
the
detection
of
pathogens
in
water
has
not
been
demonstrated.

Response:
See
response
to
0019/
20
part
15
in
section
5.2.4.2.

Docket
ID
­
Part
#

Comment:
0019/
20
17
It
is
not
clear
how
the
agency
is
proposing
to
use
VFAR
technology.
An
interpretation
of
the
various
sections
in
the
notice
leads
to
two
possible
applications:

1.
Comparing
the
genetic
sequence
of
a
defined
organism
with
unknown
properties
against
the
GenBank
database
to
determine
whether
the
organism
possesses
virulence
genes;
and
2.
Using
a
microarray
containing
probes
specific
for
a
variety
of
virulence
factors
to
screen
nucleic
acids
extracted
from
environmental
water
samples.

Response:
EPA
remains
cautiously
optimistic
about
the
future
application
of
VFAR
to
microbial
drinking
water
contaminant
identification.
Until
further
evaluation,
it
is
not
appropriate
to
speculate
on
exactly
how
VFAR
would
be
used,
rather,
these
two
potential
applications
reflect
possible
future
uses
of
VFARs
for
microbial
contaminant
identification.

Docket
ID
­
Part
#

Comment:
0019/
20
18
The
notice
states
"
The
VFAR
principle
can
be
described
as
comparing
the
gene
structure
of
newly
identified
waterborne
pathogens
to
pathogens
with
known
genetic
structures
which
have
been
associated
with
human
disease."
If
we
already
know
they
are
waterborne
pathogens,
why
do
we
need
to
do
a
VFAR
analysis?
What
else
is
VFAR
going
to
tell
us
about
these
organisms?

Response:
The
virulence
factor
activity
relationship
concept
would
identify
potential
waterborne
pathogens
by
comparing
an
uncharacterized
organism's
genetic
sequence
to
a
known
sequence
that
is
associated
with
human
disease.
In
addition,
characterizing
a
newly
identified
pathogen
and
the
number
of
factors
that
could
lead
to
human
disease
may
also
assist
in
prioritization
among
similarly
identified
organisms.
It
may
also
identify
similarities
within
the
gene
structure
of
waterborne
pathogens
to
genetic
elements
of
pathogens
associated
with
human
disease,
that
have
not
been
identified
as
waterborne.
This
could
indicate
the
need
to
consider
these
organisms
for
future
CCLs.
Also
see
the
response
to
comment
19/
20
part
12,
13,
and
14
in
section
5.2.4.2
on
the
use
of
virulence
factor
activity
relationships.

Docket
ID
­
Part
#
51
Comment:
0019/
20
19
The
notice
also
states
that
EPA
searched
for
genetic
sequences
associated
with
virulence
using
the
NCBI
GenBank
database,
but
"
the
data
were
in
a
form
that
proved
difficult
to
use
for
this
purpose."
The
information
provided
in
GenBank
is
raw
nucleic
acid
sequences
so
it
is
not
clear
why
this
would
be
unsuitable.
What
else
would
be
needed
other
than
nucleic
acid
sequences
and
what
was
the
agency
expecting
to
get
from
this
piece
of
work?

Response:
GenBank
contains
an
immense
amount
of
genetic
sequence
data
on
virulence­
related
genes.
GenBank
is
a
very
rich
data
source,
but
the
overwhelming
amount
of
data
makes
its
interpretation
very
difficult.
There
is
currently
little
standardization
of
gene
identification
or
use
of
keywords,
and
there
is
significant
overlap
of
genetic
sequences.
The
specificity
of
keyword
searches
is
problematic
because
of
the
uncertain
relationship
of
sequences
identified
by
keyword
searches
to
expressed
virulence
of
the
pathogen
in
the
host,
and
the
function
of
shared
sequences
in
different
organisms.
The
genetic
sequence
similarity
search
results
were
often
of
little
use
in
finding
virulence
genes
in
other
organisms.
Similarities
were
often
found
between
partial
sequences
from
the
same
gene
in
the
same
species
in
the
database,
or
similarities
were
found
with
small
areas
of
human
or
fruit
fly
genes.
In
many
cases
results
included
ribosomal
or
other
structural
genes
which
are
unlikely
to
confer
virulence.
The
lack
of
convincing
identification
of
genes
for
bacteria
and
the
complete
lack
of
identification
of
viral
gene
function
in
GenBank
makes
interpretation
of
data
difficult.
When
homologous
sequences
are
identified
some
means
of
recognizing
the
significance
of
sequence
matches
is
needed,
particularly
when
the
percentage
of
homology
between
two
or
more
sequences
is
low,
or
only
a
portion
of
a
gene
aligns.
The
search
for
virulence
genes
using
keywords
proved
to
be
very
difficult
on
the
GenBank
database
which
is
really
a
warehouse
of
mostly
raw
data.
Many
sequences
are
the
result
of
different
laboratories
working
to
sequence
the
same
gene,
and
some
of
these
may
overlap
while
others
can
be
in
different
regions
of
the
gene.
The
identification
of
the
gene
and
its
function
is
often
based
on
genetic
similarities
to
genes
of
known
function
in
a
family,
but
this
does
not
guarantee
the
same
function.
This
means
that
many
genes
that
occur
in
GenBank
entries
are
for
hypothetical
proteins
or
that
they
code
for
proteins
with
a
putative
function.
This
makes
interpretation
very
difficult.
Another
difficulty
with
keyword
searches
on
GenBank
is
that
they
return
positive
results
not
only
when
the
keyword
is
a
descriptor
for
a
gene,
but
also
when
it
appears
in
the
title
of
the
source
paper
or
anywhere
else
in
the
text
of
the
page
that
contains
the
data.
Other
databases
of
genomic
information,
for
example
The
Institute
for
Genomic
Research
Comprehensive
Microbial
Resource
(
TIGR),
are
much
smaller
than
GenBank,
but
are
more
organized
and
easier
to
search.

Docket
ID
­
Part
#

Comment:
0019/
20
20
In
addition,
the
notice
states
that
the
agency
is
working
with
the
NDWAC
CCL
Work
Group
to
evaluate
bioinformatics
for
extracting
relevant
information
from
databases
and
literature
sources.
The
information
"
could
provide
the
gene
sequences
needed
to
demonstrate
the
potential
use
of
gene
chip
technology
in
performing
VFAR
analysis."
It
is
not
at
all
clear
how
such
an
effort
will
provide
gene
sequences.

Response:
The
results
of
bioinformatics
searches
conducted
in
support
of
the
national
Drinking
Water
52
Advisory
Councils's
Work
Group
may
identify
virulence
gene
sequences
in
the
available
literature
and
data
sources.
By
identifying
gene
sequences
from
previous
and
on­
going
scientific
sequences
could
be
identified
and
one­
day
used
with
gene
chip
technology
to
look
for
their
presence
in
drinking
water
samples
in
outbreak
situations.
This
type
of
evaluation
across
research
efforts
could
provide
additional
information
in
feasibility
of
molecular
and
genomic
techniques
for
future
efforts.

Docket
ID
­
Part
#

Comment:
0019/
20
21
The
take­
home
lesson
is
simply
that
just
because
an
organism
has
the
genes
for
a
given
cellular
product
does
not
mean
it
can
use
them
for
the
predicted
function.

Molecular
detection
tools
applied
to
environmental
samples
do
not
necessarily
correlate
with
presence
of
either
actual
organisms
or
viable
organisms.
Nucleic
acids
can
persist
inside
dead
organisms,
exist
free
in
the
environment
for
considerable
periods
of
time
(
depending
on
the
particular
characteristics
of
the
sample
matrix),
and
will
be
detected
by
many
molecular
methods.
An
approach
to
avoid
this
limitation
is
to
target
RNA
instead
of
DNA,
but
this
presents
even
more
sample­
processing
problems
than
targeting
DNA.

Finally,
a
question
that
the
agency
should
ask
and
answer
is,
"
What
is
the
benefit
of
spending
money
to
pursue
the
VFAR
approach
that
provides
a
probability
that
a
pathogen
may
cause
adverse
health
effects,
rather
than
getting
a
better
handle
on
what
is
actually
making
people
sick
through
increased
public
health
surveillance?"

Response:
We
will
consider
these
ideas
as
we
develop
the
CCL
process.
It
is
also
important
to
note
that
the
virulence
factor
activity
relationship
is
one
tool
in
a
tool
box
to
identify
evaluate
pathogens
for
the
CCL.
The
National
Drinking
Water
Advisory
Council
specifically
recommends
that
EPA
works
with
other
Agencies
involved
in
public
health
surveillance,
consider
methods
to
identify
waterborne
disease
and
outbreak
information,
and
confer
with
experts
to
identify
new
water­
related
disease
agents.
As
the
Agency
evaluates
these
recommendation
it
will
also
consider
the
commenters
concerns.
53
5.0
Implementation
of
NRC's
Recommendations
5.3
Other
Docket
ID
­
Part
#

Comment:
0019/
20
9
Given
the
current
short
time
line
and
limited
resource
base
for
developing
CCL
3,
AWWA
has
identified
the
following
tasks
as
critical
path
issues
that
must
be
addressed
in
order
for
the
agency
to
actually
begin
to
prepare
CCL
3.
Each
of
these
issues
must
be
addressed
in
the
next
6­
12
months:

°
Determine
how
to
involve
experts
in
the
CCL
process.
Identify
the
specific
roles,
tools,
and
points
in
the
process
in
which
the
experts
should
have
input.
Identify
specific
points
in
the
CCL
process
at
which
EPA
will
convene
the
experts
and
precisely
what
they
will
review,
what
decisions
they
will
make,
and
how
their
input
will
be
documented
and
communicated.

°
Incorporate
data
quality.
This
means
in­
depth
discussion
and
evaluation
of
options
for
incorporating
data
quality
into
the
CCL
process.
Options
should
be
tested
and
evaluated.
The
process
should
lead
to
reporting
on
challenges,
limitations,
and
specific
recommendations
for
the
incorporation
of
data
quality
into
the
CCL
process.

°
Continuous
evaluation
of
data
sources.
EPA
has
begun
this
effort.
Proposed
information
sources
need
to
be
reviewed
in
depth
and
documentation
developed
for
availability
of
relevant
data
for
the
CCL
process.

°
Select
and
characterize
contaminant
attributes.
Develop
recommendations
for
research
that
needs
to
be
done
so
that
the
attributes
and
the
data
elements
are
better
understood.
These
may
include
the
development
of
scales
and
scoring
protocols
for
the
attributes
and
the
effects
of
using
different
data
elements
to
score
the
same
attribute.
Identify
different
ways
of
combining
different
data
elements
to
score
each
attribute.

°
Address
process
performance
and
protocols
for
algorithm
applications.
Examine
in
detail
the
performance
of
alternative
CCL
development
processes,
including
the
different
statistical
approaches
proposed.
Assess
the
pragmatic
requirements
and
features
of
each
of
the
alternative
CCL
processes.
Review
complete
CCL
classification
algorithm
runs
for
a
few
alternatives.
Assess
points
of
failure,
ease
of
execution,
knowledge
base
requirements,
and
likelihood
of
success
for
each
method.

°
Develop
required
training
data
sets.
Develop
specific
principles
for
the
development
of
the
training
data
set
and
then
apply
the
principles
to
evaluating
and
listing
contaminants
on
the
training
set.

°
Determine
if
contaminant
short­
listing
is
necessary.
Determine
the
need
for
creating
and
managing
a
PCCL
versus
a
single
step
process
that
goes
from
the
universe
to
a
draft
CCL.

Response:
Your
comments
will
be
considered
as
EPA
works
toward
a
CCL
Classification
Process.
54
Docket
ID
­
Part
#

Comment:
0019/
20
40
Microbial
contaminants
should
be
given
the
same
consideration
as
the
chemical
contaminants.
For
example,
if
chemicals
and
microbes
are
evaluated
(
i.
e.,
attributes
weighed,
contaminants
scored)
through
different
processes
in
developing
the
CCL,
contaminants
of
similar
potential
public
health
concern
should
have
the
same
chance
of
placement
on
the
CCL
whether
the
contaminants
are
chemicals
or
microbes.
The
NDWAC
CCL
Workgroup
also
stressed
this
recommendation.

Response:
The
Agency
thanks
the
commenter
for
their
suggestion
and
refers
the
reader
to
the
response
to
comments
0019/
20
parts
15
and
51,
under
sections
5.2.4.2
and
5.2.3.1.

Docket
ID
­
Part
#

Comment:
0019/
20
41
The
current
research
program
is
inadequate
for
CCL1,
as
the
agency
has
made
little
progress
in
moving
these
contaminants
further
through
the
regulatory
process.
EPA
must
align
drinking
water
research
funding
with
the
CCL
process.

Response:
See
the
response
to
the
comment
0019/
20
part
23,
under
section
3.1.1.2
above.

Docket
ID
­
Part
#

Comment:
0019/
20
42
Developing
a
CCL
process
that
includes
some
practical
consideration
based
on
likely
costs
and
benefits
would
be
consistent
with
both
CCL1
and
regulatory
determinations
made
to
date.

Response:
The
Safe
Drinking
Water
Acts
in
sections
1412(
b)(
1)
paragraphs
(
B)
and
(
C)
provide
the
principles
and
considerations
for
developing
the
CCL
considerations
to
select
contaminants.

Docket
ID
­
Part
#

Comment:
0019/
20
43
It
is
not
clear
from
either
the
NRC
or
NDWAC
CCL
Workgroup
report
what
the
actual
role
of
experts
will
be,
or
equally
important,
how
the
experts'
input
will
be
captured,
tested,
or
employed.

Response:
EPA
agrees
that
expert
judgment
and
involvement
is
important
component
to
the
CCL
selection
process,
and
is
evaluating
approaches
to
incorporate
and
document
expert
input
and
review
in
developing
the
CCL
process.
The
Agency
is
considering
recommendations
to
use
expert
workshops
as
one
approach
in
developing
the
CCL
process.
Additional
approaches
to
55
incorporate
expert
participation
in
developing
the
CCL
are
interim
product
reviews
and
public
stakeholder
meetings.
The
agency
will
also
consider
other
approaches
to
include
expert
input
and
inform
stakeholders
and
the
public
on
the
progress
the
Agency
makes
in
developing
the
CCL
process.
EPA
intends
to
incorporate
transparency
and
expert
involvement
as
key
aspects
of
the
CCL.
Also
see
response
to
comment
0019/
20
part
10
under
section
3.1.4.1.

Docket
ID
­
Part
#

Comment:
0019/
20
50
Since
expert
judgment
will
be
an
integral
part
of
the
CCL
selection
process,
it
would
be
useful
to
understand
how
experts
are
chosen
and
by
whom.
It
is
likely
that
experts
with
different
affiliations
will
come
up
with
dramatically
different
training
sets,
decisions,
and
proposed
contaminants
for
the
CCL.
Assuming
that
the
expert
panels
convened
will
include
experts
with
divergent
perspectives,
the
EPA
should
specify
the
logistics
and
rules
of
the
expert
panels.
This
needs
to
include
methods
for
resolving
disagreements
and
reaching
final
agreement
on
the
critical
elements
of
the
process.

Response:
The
Agency
will
consider
this
input
as
it
develops
the
logistics,
charge
to
experts,
and
how
best
to
conduct
reviews,
workshops,
and
meetings
to
support
the
development
of
the
CCL
process
in
a
transparent
manner.
See
the
response
to
comment
0019/
20
part
43,
under
section
5.3.

Docket
ID
­
Part
#

Comment:
0019/
20
53
The
intent
of
Section
1412(
b)
and
1445(
g)
are
further
re­
enforced
by
Section
1412(
b)((
3)(
A)
which
reads
as
follows:

"
Use
of
Science
in
Decision­
making.
 
In
carrying
out
this
section,
and,
to
the
degree
that
an
Agency
action
is
based
on
science,
the
Administrator
shall
use
 
i.
the
best
available,
peer­
reviewed
science
and
supporting
studies
conducted
in
accordance
with
sound
and
objective
scientific
practices;
and
ii.
data
collected
by
accepted
methods
or
best
available
methods
(
if
the
reliability
of
the
method
and
the
nature
of
the
decision
justifies
use
of
the
data).
[
emphasis
added]

All
of
the
above
provisions
in
Section
1412
clearly
apply
to
the
CCL.
Consequently,
the
agency
has
a
legal
responsibility
to
employ
data
developed
using
sound
and
objective
scientific
practice
and
to
use
reliable
observations,
such
as
health
effects
or
occurrence
values.

Response:
To
the
extent
that
the
commenters
interpretation
is
that
Section
1412(
b)((
3)(
A)
supercedes
the
consideration
of
data
and
information
that
indicate
anticipated
occurrence
in
public
water
systems,
EPA
disagrees.
Section
1412(
b)(
1)
paragraphs
(
B)(
i)
and
(
C)
address
the
statutory
requirements
to
list
contaminants
for
consideration.
These
sections
identify
the
organizations
that
shall
be
consulted
and
the
data
and
information
that
must
considering
in
listing
contaminants.
The
section
further
directs
the
Agency
to
publish
a
list
of
contaminants
"
that
56
at
the
time
of
publication
are
not
subject
to
any
proposed
or
promulgated
national
primary
drinking
water
regulation,
which
are
known
or
anticipated
to
occur
in
public
water
systems,
and
which
may
require
regulation
under
this
title."
It
is
important
to
note
that
the
Administrator
is
directed
to
evaluate
anticipated
occurrence.

Section
1412(
b)((
3)(
A)
directs
the
Administrator
to
use
"
i.
the
best
available,
peer­
reviewed
science
and
supporting
studies
conducted
in
accordance
with
sound
and
objective
scientific
practices;
and
ii.
data
collected
by
accepted
methods
or
best
available
methods
(
if
the
reliability
of
the
method
and
the
nature
of
the
decision
justifies
use
of
the
data).

Therefore,
in
developing
the
CCL,
EPA
will
use
the
best
available
data
in
accordance
with
sound
and
objective
scientific
practices
but
does
not
agree
that
the
CCL
should
be
limited
solely
to
the
use
of
occurrence
values
cited
by
the
commenter.

Docket
ID
­
Part
#

Comment:
0019/
20
54
From
the
regulatory
perspective,
EPA
and
the
drinking
water
community
are
accustomed
to
data
with
substantial
and
well­
defined
quality
assurance
measures.
Typically
data
are
collected
under
strict
methodological
and
quality
control
constraints.
As
the
EPA
explores
emerging
and/
or
previously
unregulated
contaminants,
the
available
data
are
likely
to
be
scarce
and
have
been
obtained
using
non­
standard
and/
or
poorly
defined
methodologies.
Consequently,
EPA
faces
a
very
challenging
environment
in
which
to
meet
the
SDWA
requirements
outlined
above.

Response:
EPA
believes
that
its
approach
to
CCL
development
will
meet
the
Congressional
objectives
set
out
in
both
1412(
b)(
1)(
B)
and
1412
(
B)(
3)(
A).

Docket
ID
­
Part
#

Comment:
0019/
20
67
AWWA
asks
that
the
agency
address
this
issue
in
finalizing
CCL
2
by
answering
the
following
questions:
1.
Will
contaminants
only
be
placed
on
the
CCL
as
individual
contaminants
and
not
in
groups
(
i.
e.,
Such
groups
would
be
a
product
of
the
regulatory
determination
or
rulemaking
phase
of
contaminant
evaluation)?
2.
Will
selection
of
groups
of
contaminants
for
placement
on
the
CCL
take
place
in
the
"
evaluation
and
expert
review"
stage
of
preparing
the
proposed
CCL
or
will
groups
of
contaminants
be
generated
prior
to
consideration
by
the
classification
algorithm?
Understanding
the
agency's
perspective
on
these
issues
will
assist
other
stakeholders
determining
how
to
best
structure
data
development
efforts.

Response:
The
Agency
is
evaluating
recommendations
and
comments
to
develop
the
next
CCL
and
refine
the
process
for
selecting
contaminants
or
groups
of
contaminants
for
future
CCLs.
As
the
Agency
identifies
and
evaluates
contaminants
for
consideration
some
of
these
contaminants
will
have
similar
modes
of
toxicologic
action,
similarities
in
occurrence,
and
57
closely
related
biology
that
provide
an
economy
of
scale
to
be
considered
as
a
group
rather
than
individual
contaminants.
The
Agency
will
consider
the
available
data
for
occurrence
and
health
effects,
input
from
experts,
and
the
commenters
request
as
it
identifies
contaminants
or
groups
of
contaminants
for
the
next
and
future
CCLs.

Docket
ID
­
Part
#

Comment:
0025
4
"
While
virulence
factor
analysis
shows
great
promise,
VFAR
is
even
further
removed
from
practical
utility
should
be
treated
with
extreme
caution.
Too
many
unknown
variables
not
exist
to
go
directly
to
VFAR
and
bypass
a
diligent
acquisition
of
knowledge
of
virulence
factors
and
expression."

Response:
The
potential
to
identify
emerging
pathogens
remains
an
important
goal
for
the
Agency,
but
our
current
evaluation
suggests
the
data
do
not
exist
to
support
a
virulence
factor
activity
relationship
implementation
for
the
next
CCL.
Important
research
steps
can
be
taken
at
this
time
to
advance
the
field
of
virulence
factor
identification.
See
the
response
to
the
comment
0019/
0020
part
12,
under
section
5.2.4.2
above.
