815Z03003
Friday,

July 18, 2003
Part V



Environmental

Protection Agency

Announcement of Regulatory
Determinations for Priority Contaminants
on the Drinking Water Contaminant
Candidate List; Notice

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   ENVIRONMENTAL PROTECTION
   AGENCY
   [FRL-7529-2]

   Announcement of Regulatory
   Determinations for Priority
   Contaminants on the Drinking Water
   Contaminant Candidate List

   AGENCY: Environmental Protection
   Agency.
   ACTION: Notice.

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

               I. General Information

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

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

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

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                                                                   42899
  The first CCL was developed with
considerable input from the scientific
community and stakeholders. EPA
published a draft CCL requesting public
comment on October  6,1997 (62 FR
52193, USEPA 1997). The first final CCL
was published on March 2,1998 (63 FR
10273, USEPA 1998). The SDWA
requires that a new CCL be published
every five years. EPA is currently
preparing the next CCL. The March
1998 CCL contained 60 contaminants,
including 50 chemicals or chemical
groups and 10 microbiological
contaminants or microbial groups. Many
of these contaminants lacked some of
the information necessary to support a
regulatory determination and were
identified in the March 1998 CCL notice
(USEPA 1998) as having data needs. The
60 CCL contaminants were divided into
categories to represent research and data
needs associated with each
contaminant. The categories were: (1)
Regulatory determination priorities; (2)
health effects research priorities; (3)
treatment research priorities; (4)
analytical methods research priorities;
and (5) occurrence priorities.
  In 1998, 20 of the 60 contaminants
were classified as regulatory
determination priorities because EPA
believed that, at that time, there was
sufficient data for these contaminants to
evaluate both exposure and risk to
public health and to support a
determination of whether or not to
proceed to promulgation of a NPDWR.
Since the March 1998 CCL, EPA found
that there was insufficient information,
in the Agency's judgement, to support a
regulatory determination for 12 of the 20
priority contaminants. In addition, the
CCL-contaminant, sodium, was
reclassified and added to the list of
regulatory determination priorities as a
means of reassessing the current
guidance level for sodium. Thus, EPA is
now presenting regulatory
determinations for nine priority
contaminants that have sufficient
information to support a regulatory
determination at this  time.
  The Agency however, continues to
conduct research and/or to collect
occurrence information on the
remaining 51 CCL contaminants. EPA
has been aggressively conducting
research to fill in the data gaps and
recognizes that stakeholders may have a
particular interest in the timing of future
regulatory determinations for other
contaminants on the CCL. Stakeholders
may be concerned that regulatory
determinations for such contaminants
should not necessarily wait until the
end of the next regulatory determination
cycle. In this regard, it is important to
recognize that the Agency is not
precluded from monitoring, conducting
research, developing guidance, or
regulating contaminants not included
on the CCL as necessary and appropriate
(see SDWA sections 1412(b)(l)(B)(ii)(III)
and 1412(b)(l)(F)), or from taking action
on CCL contaminants when information
becomes available. Thus, some
regulatory determinations may be made
before the end of the next regulatory
determination cycle (i.e., August 2006).

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

HI. What Analyses Did EPA Use To
Make the Regulatory Determinations?
  The precepts for guiding EPA in
making  regulatory determinations for a
drinking water contaminant are
included in Section 1412(b)(l)(A) of
SDWA.  This section of SDWA requires
EPA to consider the following three
evaluation criteria prior to making a
regulatory decision: (1) Potential
adverse health effects from the
contaminant; (2) occurrence of the
contaminant in PWSs with a frequency
and at levels of public health concern;
and (3) whether regulation of the
contaminant would present a
meaningful opportunity for health risk
reduction for persons served by PWSs.
  EPA developed a comprehensive
approach for making regulatory
determinations with significant expert
input and recommendations suggested
by the National Research Council (NRG),
National Drinking Water Advisory
Council (NDWAC), and stakeholders.
The regulatory determination approach
is largely based on the NDWAC
recommendations. For each of the nine
contaminants, EPA evaluated the best
available peer reviewed data on health
effects, and approximately seven
million analytical data points on
contaminant occurrence. For those
contaminants with adequate monitoring
methods, as well as health effects and
occurrence data, EPA applied an
approach in making regulatory
determinations that followed the
NDWAC recommendations and
complies with the SDWA requirements
under Section 1412(b)(l)(A). In June
2002, EPA consulted with the Science
Advisory Board (SAB) Drinking Water
Committee and requested its review and
comment on whether the protocol EPA
developed, based on the NDWAC
recommendations, was consistently
applied and appropriately documented.
The SAB provided verbal feedback
regarding the use of the NRC and
NDWAC recommendations in EPA's
decision criteria for making its
regulatory determinations, as well as its
interest in remaining involved in future
regulatory determinations. SAB
recommended that the Agency provide
a transparent and clear explanation of
the process for making regulatory
determinations. In today's
announcement and in the
documentation supporting this
announcement, the Agency has taken
the SAB recommendation into
consideration in explaining the
evaluation process used to make today's
regulatory determinations.
  EPA characterized the human health
effects that may result from exposure to
a contaminant found in drinking water.
Based on this characterization, EPA
estimated a health reference level (HRL)
or benchmark value for each
contaminant. EPA has prepared Health
Effects Support Documents or Drinking
Water Advisories (USEPA 2002c and
2003a-g) for each contaminant, which
are available at the EPA Water Docket
and on-line at http://www.epa.gov/
edocket/. The support documents
address the following: Exposure from
drinking water and other media;
toxicokinetics; hazard identification;
dose-response assessment; and an
overall characterization of risk from
drinking water.
  Using the Agency's Unregulated
Contaminant Monitoring (UCM)
program data and National Inorganic
and Radionuclide Survey (NIRS) data,
EPA estimated the number of PWSs and
the population served by the PWSs at
the benchmark values, and the

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geographic distribution, using a large
amount of State occurrence data that are
generally indicative of national
occurrence. The UCM data form part of
the Agency's basis for its estimates of
national occurrence since these data
provide occurrence information for
several unregulated contaminants. The
NIRS data provide a statistically
representative sample of the national
occurrence of many other unregulated
and regulated inorganic contaminants in
ground water community water supplies
(CWSs).
  EPA also employed other State
drinking water data, use and
environmental release information (e.g.,
EPA's Toxic Release Inventory (TRI),
academic and private sector
publications), as well as ambient water
quality data (i.e., source water existing
in surface waters and aquifers before
extraction and treatment as drinking
water), to augment the UCM drinking
water data and to evaluate the
likelihood of contaminant occurrence.
EPA included, when available, data
from the U.S. Geological Survey's
(USGS) National Water Quality
Assessment program.
  A detailea discussion of the data
collected and analyses for each
contaminant can be found in the
respective regulatory determination
support document. The regulatory
determination support documents
(USEPA 2001a-g) are available in the
EPA Water Docket.
  The underlying data and analysis
supporting the findings used by the
Agency to make the regulatory
determinations are summarized in the
June 2002 notice (USEPA  2002a).
IV. Summary of Public Comments and
the Agency's Responses on the CCL
Regulatory Determination Process
  The comment period on the June 3,
2002, notice ended on August 2, 2002.
EPA received 15 comments on the
preliminary regulatory determinations
for the nine CCL contaminants
published by EPA in the June 2002
notice (USEPA 2002a). Four comments
were received from water  systems and
related associations, seven from
industry groups, two from
environmental advocacy groups, one
from a State agency and one from a
State-related association. Although most
commenters generally approved of
EPA's determination not to regulate any
new contaminants at this time, some
commenters expressed concerns about
the process associated with EPA's
regulatory determinations for these nine
contaminants, as well as with CCL
activities not specifically related to the
preliminary determinations.
                 A majority of the comments were
               focused on five over-arching topic areas:
                 1. Some commenters expressed
               concern over the transparency of the
               CCL decision-making process.
                 2. Several industry groups expressed
               a concern that the health effects
               assessments were too conservative.
                 3. Several commenters expressed
               concern with EPA's progress in filling
               research gaps related to the CCL and
               encouraged EPA to publicly track
               research needs and progress on
               remaining CCL contaminants.
                 4. The majority of commenters
               generally approved of EPA's
               determination not to regulate any new
               contaminants at this time. However, one
               commenter questioned the
               appropriateness of EPA's decisions not
               to regulate any of the nine priority
               contaminants.
                 5. Several comments were received
               regarding contaminants on the CCL for
               which draft regulatory determinations
               were not included in the June 2002
               notice, including perchlorate and
               methyl-t-butyl ether (MTBE).
                 A complete copy of the public
               comments and the Agency's responses
               are included in the Docket for today's
               action. The remainder of this section
               discusses the five key topic areas
               identified by commenters in response to
               the June 2002 CCL regulatory
               determination notice (USEPA 2002a).
               1. Lack of Transparency of Regulatory
               Determination Approach
                 Comment Summary: Several
               commenters expressed a concern about
               the "lack of transparency" in the
               regulatory determination approach used
               by the Agency for the June 2002 notice.
               Most of those commenters suggested
               that EPA did not provide an adequate
               explanation  for the reduction in the
               number of the priority contaminants
               from twenty to nine since the
               publication of the first CCL in March
               1998 (USEPA 1998). These commenters
               suggested that the Agency needs to
               provide better justification regarding the
               reasons for excluding the twelve
               contaminants listed in the March 1998
               CCL from the regulatory determination
               process.
                 Several commenters suggested that
               this regulatory determination process
               approach does not provide for enough
               participation from outside groups for
               the development of non-regulatory
               strategies. These commenters suggested
               that the Agency should allow for more
               meaningful public involvement in the
               regulatory determination process. One
               commenter stated that, given the
               Agency's analysis of occurrence and
               health effects data over several years,
the 60-day comment period was not
adequate to allow "detailed analysis by
interested stakeholders."
  Other commenters, however, observed
that the CCL regulatory determination
approach taken by EPA was "reliably
consistent" with the basic charge of the
SDWA and the NDWAC workgroup
recommendations. Several commenters
noted that, by EPA following the
protocol recommended by the NDWAC
Work Group, stakeholders were assured
that the Agency used the "best-
available, peer-reviewed science" in
these determinations.
  Agency Response: EPA developed a
consistent regulatory determination
approach for evaluating CCL
contaminants that followed NDWAC's
recommended protocol for health effects
and occurrence analysis. The regulatory
determination approach for each
contaminant on the list included an
evaluation of the adequacy of current
analytical and treatment methods, the
best available peer-reviewed data on
health effects, and an occurrence data
set of about seven million contaminant
occurrence data points.
  By using this approach, EPA
determined that, at the time of the June
2002 notice (USEPA 2002a) of
preliminary regulatory determinations
there was not sufficient information to
support a regulatory determination on
twelve of the twenty priority
contaminants. As noted previously, the
CCL-contaminant, sodium, was moved
to the list of regulatory determination
priorities to allow an update of the
Agency's position on the issue of
sodium in drinking water.
  The NDWAC, which is comprised of
representatives from the general public,
State and local agencies, and  private
groups concerned with  drinking water
safety, was convened to provide input
during the regulatory determination
process. Throughout the regulatory
determination process, EPA's approach
has been to maintain a strong
partnership with stakeholders and
involve them to the maximum extent
possible, thereby helping to ensure that
stakeholders understand the regulatory
determination process and provide
valuable input.
  The Agency agrees that a meaningful
opportunity for discussions with
stakeholders is an important component
of the CCL Regulatory Determination
process. The Agency utilized a variety
of mechanisms to involve stakeholders
in the process. These included two
broad-based stakeholder meetings, one
in November 1999 and one in July 2002.
Members of the public also were invited
to attend the three sessions of the
NDWAC Work Group in the Spring/

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                                                                    42901
Summer of 2000, which focused on
protocol recommendations to the
Agency. In addition, EPA
representatives delivered presentations
at a variety of meetings held by other
organizations. Moreover, EPA did ask
for and considered comments made on
the sodium and sulfate Drinking Water
Advisories during the comment period
on the June 2002 notice (USEPA 2002a).
  The Agency believes the 60-day
public comment period for the June
2002 notice (USEPA 2002a) was
sufficient. The Agency took steps to
facilitate public review of its
preliminary decisions, as well as
supporting documentation. In addition
to the July 2002 stakeholder meeting,
these steps included making key
materials available on the Agency's
website and providing hard copies of
materials upon request.

2. Health Effects Assessments
  Comment Summary: Some
commenters suggested that EPA's
analysis of adverse health effects and
calculation of the HRLs were too
conservative. On the other hand, one
commenter questioned how the
Agency's analysis underlying the
regulatory determination approach
incorporated appropriate safety factors
and exposure assessments relative to
children's health concerns.
  Commenters recommended that EPA
use the revised Office of Water
methodology for deriving ambient water
quality criteria (AWQC), (USEPA 2000),
in an effort to protect human health in
the final health effects  support
documents. According to the comments,
this revised methodology establishes
five different consumption rates and
body weight classifications as a means
to make the human health exposure
assessments. One commenter specified
that EPA needs to use more accurate
consumption data for sodium rather
than simply incorporating U.S. Food
and Drug Administration (FDA)
assertions.
  Agency Response: EPA believes it is
appropriate to use a conservative
approach to assessing the health effects
of an unregulated contaminant in the
context of a determination of whether it
should be considered for NPDWR
regulation. In order to determine
whether to propose an  NPDWR for an
unregulated contaminant, SDWA
requires EPA to determine whether the
contaminant "may have an adverse
effect on the health of the persons,"
Section  1412(b)(l)(A)(i), which is a very
broad criterion. As a result, EPA
believes that a conservative health
effects analysis is appropriate.
  The HRL used by EPA in these
determinations is a conservative health-
based value and is different depending
on whether a contaminant is considered
a carcinogen or a noncarcinogen. For
carcinogens, a 10-6 risk was chosen as
the HRL since the maximum
contaminant level goal (MCLG) for such
contaminants will generally be zero. For
noncarcinogens, the reference dose and
a 20 percent relative source contribution
(RSC) factor was used in conjunction
with a 70 kilogram (kg) adult body
weight and a 2 liter (L) water intake for
the HRL calculation. EPA uses these
standard regulatory assumptions for
determining the MCLG of a
noncarcinogen that lacks specific data
on the RSC. EPA used best available
peer reviewed data and analyses in
evaluating adverse health effects.
Accordingly, EPA disagrees with those
commenters that felt that EPA was too
conservative in establishing the HRL.
EPA followed practices and policies that
are similar to those used to establish an
NPDWR and that are consistent with the
SDWA section 1412(b)(l)(A)(i) criterion.
If such a conservative approach does not
result in EPA deciding to initiate a
regulatory process for a contaminant,
the Agency may decide to use a non-
regulatory approach in addressing the
issue, such as issuing a Drinking Water
Advisory.
  Children's health issues were
considered in making regulatory
determinations for each of the nine
contaminants included in this final
notice. The details of the individual
assessments  are included in the Health
Effects Support Documents or Drinking
Water Advisories for each contaminant.
These documents are available for
review at the EPA Water Docket and on-
line at http://www.epa.gov/edocket/.
  The AWQC (USEPA 2000)
methodology continues to recommend
the use of 70 kg for adult body weight
and 2 liters per day for water intake for
risk calculations. These are the same
parameters used by EPA to derive an
MCLG. EPA believes that its current
methodology, based on adult exposures,
for the derivation of MCLGs, and for
making regulatory determinations under
SDWA section 1412, remains generally
appropriate.  EPA has not yet
determined a protocol for making a
regulatory determination for a chemical
for which an infant's or a particular
childhood age grouping's body weight
and drinking water intake would be the
basis of a regulatory action. A  decision
for such a contaminant would be made
on the basis of the toxicity and exposure
data, and could utilize the age groupings
and body weight information from the
AWQC human health methodology if it
were appropriate.
  EPA did not use FDA's sodium
consumption data of 4 to 6 grams/day
(g/day) in establishing a benchmark
value for sodium. EPA decided to use a
benchmark value for sodium instead of
an HRL because sodium lacks suitable
dose-response data and there is
considerable controversy regarding the
role of sodium in the etiology of
hypertension. EPA derived the
benchmark value for sodium of 120 mg/
L in drinking water from the National
Institutes of Health, National Academy
of Sciences, American Heart
Association, and the U.S. Department of
Agriculture recommended daily dietary
intake of 2.4 g/day.
3. EPA Besearch Agenda
  Comment Summary: Several
commenters  expressed concern that, in
their view, there is a lack of progress by
EPA in filling research gaps  related to
the CCL. In particular, commenters
focused on high visibility contaminants,
such as the microbiological
contaminants, MTBE, and other
"emerging contaminants." Commenters
also stressed the need to establish a
vehicle for publicly tracking research
needs and progress made in research
areas.
  Agency Response: Before EPA can
determine whether to regulate
contaminants, additional data on health,
treatment technologies, and  analytical
methods, are needed for contaminants
on the Research Priorities portion of the
CCL, and occurrence data is needed for
contaminants on the Occurrence Data
Needs portion of the CCL. The
remaining 51 CCL contaminants for
which decisions are not being made
today do not have sufficient data to
support a regulatory determination. The
Agency considers obtaining  this data to
be the priority of its research and
occurrence monitoring programs. The
Agency continues to actively conduct
research and/or to collect occurrence
information on these 51 CCL
contaminants and other emerging
contaminants. Because these research
issues are broader than those that EPA
can address alone, it is anticipated that
other entities will be involved in
conducting much of the needed research
to support this process. For example,
EPA already is jointly undertaking
research efforts, and encourages
stakeholders, through close and regular
consultation, to be partners in filling
many of the research gaps. The EPA
continues to identify and develop new
collaborations to conduct research and
gather the additional data to
characterize  occurrence and adverse

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health effects to support future
regulatory determinations of CCL
contaminants. EPA is also engaged with
our stakeholders in a NDWAC work
group to refine the CCL listing process
to address emerging contaminants for
future efforts.
  EPA agrees with the comment
concerning the importance of
establishing a vehicle that will allow
stakeholders to track the status of
drinking water research projects. EPA is
committed to providing a means for
stakeholders to track research needs and
progress made in research areas, and is
developing a web-based research
inventory that is expected to be
available to the public in 2003. This
website will serve as a repository of
information on drinking water research
projects currently funded or performed
by the EPA.

4. Criticism of Regulatory Decisions
Made
  Comment Summary: One commenter
expressed concern that EPA's decision
not to regulate any of the nine priority
contaminants was not appropriate. A
comment submitted and co-signed by 22
environmental organizations disagreed
with the regulatory determinations for
four contaminants,
hexachlorobutadiene, manganese,
sodium and sulfate. The commenters
believe that EPA's monitoring  data
presented in the June 2002 notice shows
that over 22,000 people were exposed to
hexachlorobutadiene at concentrations
above the HRL. The commenters assert
that although EPA says manganese has
low toxicity, EPA finds that nearly 3%
of the population exceeded EPA's HRL.
The commenters also disagreed with the
Agency determination that regulation is
not warranted because food sources of
sodium  are a more significant
contribution to sodium in the diet than
drinking water. The commenters also
assert that EPA should regulate sulfate
because EPA's monitoring data shows
that millions of Americans are likely to
have sulfate levels above the HRL in
their drinking water, which puts infants
and other subpopulations at risk.
  Agency Response: The preliminary
regulatory determinations on whether or
not to regulate the nine priority
contaminants were based on the three
SDWA statutory requirements, and the
contaminants were evaluated in terms of
national significance. EPA's assessment
of the health effects and national
occurrence were discussed in detail in
the June 2002 notice. EPA disagrees that
each of the contaminants identified by
the commenters should be regulated.
The rationale supporting the regulatory
determination is provided below.
                 EPA found that hexachlorobutadiene
               occurs in systems, but not at a frequency
               or level of public health concern. The
               commenter has misinterpreted the
               monitoring data presented in the June
               2002 notice. The number 22,736 in the
               notice refers to the number of reporting
               PWSs in the monitoring data set and
               does not reflect the number of people
               exposed to hexachlorobutadiene
               concentrations above the HRL. The June
               2002 notice states that 0.02% (4 out of
               22,736) reporting systems detected
               hexachlorobutadiene above the HRL
               affecting 0.005% (3,350 out of the 67
               million) of the population served by
               these systems (67 FR 38235). Because of
               this low frequency, EPA believes it is
               most appropriate at this time to address
               occurrence of hexachlorobutadiene at
               the State level rather than at the
               national level.
                 EPA disagrees with the commenter's
               criticism of the decision not to regulate
               manganese. Manganese is an essential
               trace element needed for the normal
               healthy growth and function of animals
               as well as human beings.  Therefore, the
               decision whether or not to regulate
               manganese needs to balance the concern
               for the potential toxic effects from high
               oral exposure with the concern for
               adverse effects from manganese
               deficiency. In 2001, the Institute of
               Medicine (IOM) set an adequate level
               for manganese at 2.3 mg/day for men
               and 1.8 mg/day for woman.
                 Furthermore, in 2001, the IOM set a
               tolerable upper intake level for
               manganese at 11 mg/day. While 3% of
               the population may be exposed to
               manganese at levels above the 0.30 mg/
               L HRL for drinking water, this level is
               well below the IOM tolerable level. For
               example, assuming a daily intake of 2
               liters of drinking water with manganese
               at the HRL of 0.30 mg/L, the daily intake
               of manganese from drinking water at the
               HRL would only expose a person to 0.6
               mg/day. This value is well below lOM's
               11 mg/L adequate level for manganese
               and represents only 5.5% of lOM's
               upper limit for manganese. Public
               drinking water accounts for a relatively
               small proportion of a person's
               manganese intake, even at the HRL.
               Therefore, the Agency concludes that
               regulation of drinking water for
               manganese does not provide a
               meaningful opportunity to reduce the
               risk of adverse health effects. The
               commenter is referred to the CCL
               Preliminary Regulatory Determination
               Support Document for Manganese (EPA
               815-R-01-013) for a more detailed
               discussion of this issue.
                 EPA disagrees with the commenter's
               criticism of the decision not to regulate
               sodium. Because sodium  in drinking
water is a very small contributor to daily
dietary intake and because the levels at
which sodium intake can contribute to
increasing the blood pressure of
individuals with normal blood
pressures is not clearly established, EPA
does not believe that a NPDWR for
sodium presents a meaningful
opportunity for public health protection
at this time.
  EPA disagrees with the commenter's
criticism of the decision not to regulate
sulfate. EPA used current data (Round 2
of the UCM program) that indicate that
about 1.8% of the reporting systems
serving approximately 2 million people
from a 20-state cross section of the
unregulated contaminant monitoring
study exceeded 500 mg/L. Although
additional data from six states had very
similar results, EPA found  that the
weight of evidence suggests that the
adverse health effect is generally mild,
of short duration, and generally occurs
at concentrations considerably greater
than 500 mg/L, except in very limited
circumstances when contaminants that
exacerbate the effects of sulfate are also
present in the water. Therefore, EPA has
made the determination not to regulate
sulfate with a NPDWR at this time
because regulation would not present a
meaningful opportunity for health risk
reduction for persons served by public
drinking water systems. However, EPA
prepared a Drinking Water Advisory to
provide guidance to communities that
may be exposed to drinking water with
high sulfate concentrations. This
advisory contains information of use to
sensitive sub-populations,  such as
infants and travelers.
5. Stakeholder's Highest Priority for
Future Regulatory Determinations
  Comment Summary: Commenters
encouraged EPA to be aggressive and
consider an expedited regulatory
determination for several CCL
contaminants including MTBE and
perchlorate.
  Agency Response: For this regulatory
determination, EPA developed a
comprehensive evaluation  approach
based on the recommendations from
NRC and NDWAC. As explained in the
June 2002 notice (USEPA 2002a), this
evaluation satisfies the three SDWA
requirements under section
1412(b)(l)(A)(iH"i)- For each of the
contaminants, the Agency evaluated the
adequacy of current analytical and
treatment methods, the best available
peer-reviewed data on health effects,
and an occurrence data set of
approximately seven million analytical
data points. At this time, EPA does not
believe adequate data exists in these key
areas to make a regulatory

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                                                                    42903
determination either for perchlorate or
MTBE. EPA is, gathering information to
fill the data gaps for these contaminants.
  With respect to perchlorate, EPA is
gathering national occurrence data on
perchlorate in drinking water through
the Unregulated Contaminant
Monitoring (UCM) Rule. The Agency is
also completing a rigorous peer review
of health effects studies and is
developing a final toxicity review and
risk characterization. As part of this
effort, EPA has asked the National
Academy of Sciences to review science
issues related to the 2002 draft EPA risk
assessment for perchlorate. In addition,
the Agency is funding research studies
on treatability of perchlorate for PWSs.
Some of the technology currently in use
at hazardous waste sites is being
evaluated for the feasibility of using it
in water treatment at community water
systems. At the  same time, EPA is
seeking to improve the analytical
method sensitivity that would allow
concentrations of perchlorate to be
quantified at lower levels than are
presently possible. The Agency is
moving concurrently in each of these
areas to meet data and research needs as
quickly as possible. When the necessary
information is collected, we plan to
move forward with a regulatory
determination. In this regard, it should
be emphasized that where EPA
determines there is sufficient
information on this or any other
unregulated contaminant, the Agency is
prepared to act in advance of the next
five year regulatory determination cycle.
  Regarding MTBE, on-going activities
will provide the Agency with improved
health effects and occurrence data. At
this time, EPA is preparing its revised
risk assessment for MTBE for peer
review. The Agency established the
1997 Drinking Water Advisory for
MTBE at 20-40  micrograms per liter
(ug/L, or parts per billion, ppb) to avoid
unacceptable taste and odor and provide
a protective margin of exposure for
adverse health effects. The 20-40 ppb
level was not based on the possible
cancer risks. As a result of the UCM
Rule, data from  PWSs required to
monitor for MTBE will be available in
the middle of 2004.

V. Summary of the Agency's Findings
on the Nine CCL Contaminants

A. Acanthamoeba
  Description: Acanthamoeba is a free-
living protozoa commonly found in
water, soil, and  air. Species of this
microbe have been isolated worldwide
from brackish and sea water, tap water,
bottled water, airborne dust, swimming
pools, hot springs, thermal effluents of
power plants, ocean sediments,
vegetables, and hot tubs. Acanthamoeba
species have been associated with
human infections affecting the eye,
lung, brain, and skin. Acanthamoeba
has been recovered from the nose and
throat of humans with impaired
respiratory function and from
apparently healthy persons, suggesting
that the amoeba is commonly inhaled.
  Agency Findings: After reviewing the
best available public health and
occurrence information, EPA has made
the determination not to regulate
Acanthamoeba with a NPDWR at this
time, because regulation would not
present a meaningful opportunity for
health risk reduction for the people
served by public drinking water systems
(PWSs). As noted in the June 2002
notice (USEPA 2002a), EPA has no
national monitoring data to indicate
occurrence of Acanthamoeba cysts in
drinking water, and filtration practices
commonly used to treat drinking water
remove Acanthamoeba cysts.
  A complete review of EPA's analysis
of the health effects, occurrence, and
exposure for Acanthamoeba were
presented in the June 2002 notice
(USEPA 2002a) and in the health effects
support document for Acanthamoeba
(USEPA 2003h). EPA intends to release
a guidance document for Acanthamoeba
that will be directed mainly to contact
lens wearers and will address the risks
of Acanthamoeba eye infection
associated with improper  care of contact
lenses.
B. Aldrin and Dieldrin
  Description: Aldrin and dieldrin
(Chemical Abstract Services Registry
Number (CASRN) 309-00-2 and 60-57-
1, respectively) are the common names
of two structurally similar insecticides.
They are discussed together because
aldrin readily changes to dieldrin in the
body and in the environment, and they
cause similar adverse health effects.
From 1950-1970, aldrin and dieldrin
were popular pesticides used for crops,
such as corn and cotton. Because of
concerns about damage to the
environment and the potential harm to
human health, EPA banned most uses of
aldrin and dieldrin in 1974, except for
the control of termites, and banned all
uses outright since 1987. According to
the Agency for Toxic Substances and
Disease Registry (ATSDR), aldrin and
dieldrin have not been produced in the
United States since 1974 (ATSDR 1993).
  Agency Findings: After reviewing the
best available public health and
occurrence information, EPA has made
the determination not to regulate aldrin
or dieldrin with a NPDWR at this time,
because regulation would  not present a
meaningful opportunity for health risk
reduction for the people served by
PWSs. EPA recognizes that aldrin and
dieldrin are probable human
carcinogens, but the chemicals have
been banned for most uses since 1974,
and have a low frequency and low level
of occurrence in drinking water
supplies.
  A complete review of EPA's analysis
of the health effects, occurrence, and
exposure for aldrin and dieldrin were
presented in the June 2002 notice
(USEPA 2002a)  and in the regulatory
determination (USEPA 2001a) and
health effects (USEPA 2003a) support
documents for aldrin and dieldrin.
C. Hexachlorobutadiene
  Description: Hexachlorobutadiene
(CASRN 87-68-3) is a VOC that  is
relatively insoluble in water (solubility
of 2-2.55 mg/L). Hexachlorobutadiene is
mainly used to make rubber
compounds. It is also used in
gyroscopes, as a heat transfer liquid, as
a hydraulic fluid, as a solvent, and to
make lubricants. It has never been
manufactured as a commercial product
in the United States, however, it is
imported and significant quantities of
the chemical are generated in the United
States as a waste by-product from the
chlorination of hydrocarbons.
  Most exposure to
hexachlorobutadiene comes from
breathing contaminated air in the
workplace environment.  People  living
near hazardous  waste sites containing
hexachlorobutadiene may be exposed to
it by breathing air or by drinking
contaminated water.
  Agency Findings: After reviewing the
best available public health and
occurrence information, EPA has made
the determination not to  regulate
hexachlorobutadiene with a NPDWR at
this time, because it would not present
a meaningful opportunity for health risk
reduction for persons served by PWSs.
Hexachlorobutadiene occurs in PWSs,
but not at a frequency or level of public
health concern.
  A complete review of EPA's analysis
of the health effects, occurrence, and
exposure for hexachlorobutadiene were
presented in the June 2002 notice
(USEPA 2002a)  and in the regulatory
determination (USEPA 2001b) and
health effects (USEPA 2003b) support
documents for hexachlorobutadiene.
D. Manganese
  Description: Manganese (CASRN
7439-96-5) is a naturally occurring
element found at low levels in soil,
water, and food. It is an essential trace
element for humans and  all animal
species. It constitutes approximately 0.1

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percent of the earth's crust, however, it
does not occur in the environment in its
pure metal form, but is ubiquitous as a
component of more than 100 minerals
including many silicates, carbonates,
sulfides, oxides, phosphates, and
borates (ATSDR 2000).
  Manganese is generally considered to
have low toxicity when ingested orally.
The major source of manganese intake
in humans (with the exception of
possible occupational  exposure) is
dietary ingestion; manganese is a
nutrient and is not considered to be very
toxic when ingested with food. Reports
of adverse effects following oral
exposure are rare.
  Agency Findings: After reviewing the
best available public health and
occurrence information, EPA has made
the determination not  to regulate
manganese with a NPDWR at this time,
because it would not present a
meaningful opportunity for health risk
reduction for persons served by PWSs.
Manganese is generally not considered
to be very toxic when ingested with the
diet and drinking water accounts for a
relatively small proportion of
manganese intake.
  A complete review of EPA's analysis
of the health effects, occurrence, and
exposure for manganese were presented
in the June 2002 notice (USEPA 2002a)
and in the regulatory determination
(USEPA 2001c) and health effects
(USEPA 2003c) support documents for
manganese. EPA is developing a
Drinking Water Advisory for manganese
to provide guidance to communities that
might be exposed to elevated
concentrations of manganese in their
drinking water.
E. Metribuzin
  Description: Metribuzin (CASRN
21087-64-9) is a pesticide that does not
volatilize readily, yet is relatively
soluble in water. It is relatively
persistent in the environment and
degrades primarily through exposure to
sunlight. Metribuzin is used as an
herbicide on soybeans, potatoes, alfalfa,
sugar cane, lentils, asparagus, tomatoes,
carrots, peas, barley, wheat, range
grasses, and Christmas trees. Metribuzin
has limited non-agricultural utility.
Metribuzin is not classifiable as  a
human carcinogen, but there may be
effects on the liver and body weight
from chronic exposure to high doses.
  Agency Findings: After reviewing the
best available public health and
occurrence information, EPA has made
the determination not  to regulate
metribuzin with a NPDWR at this time,
because it would not present a
meaningful opportunity for health risk
reduction for persons served by PWSs.
               Metribuzin is not known to occur in
               PWSs at levels of public health concern.
               National monitoring data indicate that
               metribuzin is infrequently detected in
               public water supplies.
                 A complete review of EPA's analysis
               of the health effects, occurrence, and
               exposure for metribuzin were presented
               in the June 2002 notice (USEPA 2002a)
               and in the regulatory determination
               (USEPA 2001d) and health effects
               {USEPA 2003d) support documents for
               metribuzin.

               F. Naphthalene
                 Description: Naphthalene (CASRN
               91-20-3) is a VOC that is naturally
               present in fossil fuels, such as
               petroleum and coal, and is formed when
               wood or tobacco are burned.
               Naphthalene is produced in commercial
               quantities from either coal tar or
               petroleum. Most naphthalene use (60%)
               is as an intermediary in the production
               of phthalate plasticizers, resins,
               phthaleins,  dyes, pharmaceuticals, and
               insect repellents. Crystalline
               naphthalene is used as a moth repellent
               and as a solid block deodorizer for
               diaper pails and toilets.
                 The major source of human exposure
               to naphthalene is through the use of
               moth-balls containing naphthalene. This
               exposure can be from breathing the
               vapors or handling the mothballs.
               People also may be  exposed by
               breathing tobacco smoke and air near
               industries that use or produce
               naphthalene. Usually naphthalene is not
               found in water because it evaporates or
               biodegrades quickly. When it is found
               in water, it is usually at levels lower
               than 0.01 mg/L (ATSDR 1995).
                 Agency Findings: After reviewing the
               best available public health and
               occurrence information, EPA has made
               the determination not to regulate
               naphthalene with a NPDWR at this time,
               because it would not present a
               meaningful opportunity for health risk
               reduction for persons served by PWSs.
               Naphthalene is not known to occur in
               PWSs at levels of public health concern.
               National monitoring data indicate that
               naphthalene is infrequently detected in
               public water supplies.
                 A complete review of EPA's analysis
               of the health effects, occurrence, and
               exposure for naphthalene were
               presented in the June 2002 notice
               (USEPA 2002a) and in the regulatory
               determination (USEPA 2001e) and
               health effects (USEPA 2003e) support
               documents  for naphthalene.
               G.  Sodium
                 Description: Sodium (CASRN 7440-
               23-5) is the sixth most abundant
               element on earth and is widely
distributed in soils, plants, water, and
foods. Ground water typically contains
higher concentrations of minerals
including sodium salts than do surface
waters. In addition to naturally
occurring sources of sodium, sodium
compounds are used in deicing roads, as
water treatment chemicals, and in
domestic water softeners. Sewage
effluents can also contribute significant
quantities of sodium to water.
  Sodium is an essential trace element,
and adequate levels of sodium are
required for good health. Food is the
main source of daily human exposure to
sodium, primarily in the form of sodium
chloride (table salt). Most of the sodium
in our diet is added during food
processing and preparation.
  Agency Findings: After reviewing the
best available public health and
occurrence information, EPA has made
the determination not to regulate
sodium with a NPDWR at this time,
because it would not present a
meaningful opportunity for health risk
reduction for persons served by PWSs.
The contribution of drinking water to
daily sodium intake is very small when
compared to the total dietary intake.
Short-term excursions beyond the
benchmark values pose no adverse
health risk for most individuals,
including the majority of persons with
hypertension. Sodium in  drinking water
is a very small contributor to daily
dietary intake and the levels at which
sodium intake can contribute to
increasing the blood pressure of
individuals with normal blood
pressures are not clearly established.
The Agency currently does, however,
require monitoring for sodium at the
entry point to the distribution system
and that results be reported annually to
public health officials for surface water
systems, and every three years for
ground water systems (as defined in 40
CFR 141.41). The water supplier must
report sodium test results to local and
State public health officials, unless this
responsibility is assumed by the State.
This requirement is intended to provide
the public health community with
information on sodium levels in
drinking water to be used in counseling
patients and is the most direct route for
gaining the attention of the affected
population.
  A complete review of EPA's analysis
of the health effects, occurrence, and
exposure for sodium were presented in
the June 2002 notice (USEPA 2002a) as
well as in the regulatory determination
(USEPA 2001f) support document for
sodium. EPA is issuing a  final Drinking
Water Advisory  for sodium concurrent
with today's action (USEPA 2003f). The
sodium advisory provides guidance to

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                                                                      42905
 communities that might be exposed to
 elevated concentrations of sodium
 chloride or other sodium salts in their
 drinking water. This sodium advisory
 also provides appropriate cautions for
 individuals on low-sodium or sodium-
 restricted diets.

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

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

VII. References

ATSDR, 1993. Toxicological Profile for
    Aldrin/Dieldrin (Update). Atlanta,
    Georgia. U.S. Department of Health and
    Human Services, Public Health Service.
    184 pp.
ATSDR, 1995. Toxicological Profile for
    Naphthalene (Update). Atlanta, Georgia.
    U.S. Department of Health and Human
    Services, Public Health Service. 200 pp.
ATSDR, 2000. Toxicological Profile for
    Manganese (Update). Atlanta, Georgia.
    U.S. Department of Health and Human
    Services, Public Health Service. 466 pp.
    and Appendices.
USEPA, 1997. Announcement of the Draft
    Drinking Water Contaminant Candidate
    List; Notice. Federal Register. Vol. 62,
    No. 193, p. 52193, October 6,1997.
USEPA, 1998. Announcement of the Draft
    Drinking Water Contaminant Candidate
    List; Notice. Federal Register. Vol. 63,
    No. 40, p. 10273, March 2,1998.
USEPA, 2000. Methodology for Deriving
    Ambient Wafer Quality Criteria for the
    Protection of Human Health (2000).
    EPA-822-B-00-004. October 2000.
USEPA, 2001a. Regulatory Determination
    Support Document for Aldrin and
    Dieldrin. EPA 815 R-01-011.
USEPA, 2001b. Regulatory Determination
    Support Document for
    Hexachlorobutadiene. EPA 815 R-01-
    009.
USEPA, 2001c. Regulatory Determination
    Support Document for Manganese. EPA
    815 R-01-013.
USEPA, 2001d. Regulatory Determination
    Support Document for Metribuzin. EPA
    815 R-01-010.
USEPA, 2001e. Regulatory Determination
    Support Document for Naphthalene.
    EPA 815 R-01-008.
USEPA, 2001f. Regulatory Determination
    Support Document for Sodium. EPA 815
    R-01-014.
USEPA, 2001g. Regulatory Determination
    Support Document for Sulfate. EPA 815
    R-01-O15.
USEPA, 2002a. Announcement of
    Preliminary Regulatory Determinations
    for Priority Contaminants on the
    Drinking Water Contaminant Candidate
    List. Federal Register. Vol. 67. No. 106,
    p. 38222, June 3, 200Z.
USEPA, 2002b. Fact Sheet: Announcement of
    Preliminary Regulatory Determinations
   for Priority Contaminants on the

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    Drinking Water Contaminant Candidate
    List. EPA 815-F-02-003.
USEPA, 2003a. Health Effects Support
    Document for Aldrin and Dieldrin. EPA
    822 R-03-001.
USEPA, 2003b. Health Effects Support
    Document for Hexachlorobutadiene.
    EPA 822 R-03-002.
USEPA, 2003c. Health Effects Support
    Document for Manganese. EPA 822 R-
    03-003.
USEPA, 2003d. Health Effects Support
                    Document for Metribuzin. EPA 822 R-
                    03-004.
                USEPA, 2003e. Health Effects Support
                    Document for Naphthalene. EPA 822 R-
                    03-005.
                USEPA, 2003f. Drinking Water Advisory:
                    Consumer Acceptability Advice and
                    Health Effects Analysis on Sodium. EPA
                    822 R-03-006.
                USEPA, 2003g. Drinking Water Advisory:
                    Consumer Acceptability Advice and
                    Health Effects Analysis on Sulfate. EPA
    822 R-03-007.
USEPA, 2003h. Health Effects Support
    Document for Acanthamoeba. EPA 822
    R-0 3-012.

  Dated: July 11, 2003.
Linda J. Fisher,
Acting Administrator.
[FR Doc. 03-18151 Filed 7-17-03; 8:45 am]
BILLING CODE 6560-5

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