Friday,

July 18, 2003
Part VI



Environmental

Protection Agency

National Primary Drinking Water
Regulations; Announcement of
Completion of EPA's Review of Existing
Drinking Water Standards; Notice

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Federal  Register/Vol. 68, No. 138/Friday, July 18, 2003/Notices
 ENVIRONMENTAL PROTECTION
 AGENCY

 JFRL-7529-1J

 RIN 2040-AD67

 National Primary Drinking Water
 Regulations; Announcement of
 Completion of EPA's Review of
 Existing Drinking Water Standards

 AGENCY: Environmental Protection
 Agency.
 ACTION: Notice.	

 SUMMARY: The Safe Drinking Water Act
 (SDWA) requires the United States
 Environmental Protection Agency (EPA)
 to conduct a periodic review of existing
 National Primary Drinking Water
 Regulations (NPDWRs). EPA has
 completed its review of 69 NPDWRs
 that were established prior to 1997,
 including 68 chemical NPDWRs and the
 Total Colifonn Rule (TCR). The
 intended purpose of the review was to
 identify those NPDWRs for which
 current health risk assessments, changes
 in technology, and/or other factors,
 provide a health or technological basis
 to support a regulatory revision that will
 maintain or improve public health
 protection.
  EPA published its protocol for the
 review of NPDWRs and its preliminary
 revise/not revise decisions for the 69
 NPDWRs in the April 17, 2002, edition
 of the Federal Register (67 FR 29030
 (USEPA, 2002g)) in order to seek
 comment from the public. Today's
 action briefly describes the major
 comments, other new information, and
 EPA's current revise/not revise
 decisions for the 69 NPDWRs.
 ADDRESSES: The official public docket
 for this action is located at EPA West
 Building, Room B102,1301 Constitution
 Avenue, NW., Washington, DC.
 FOR FURTHER INFORMATION CONTACT:
 Contact: KenRotert, (202) 564-5280,
 e-mail: rotert.kenneth@epa.gov for
 inquiries regarding the TCR.  For all
 other technical inquiries contact: Judy
 Lebowich, (202) 564-4884, e-mail:
 lebowich.judy@epa.gov, or Wynne
 Miller, (202) 564-4887, e-mail:
 miller, wynne@epa.gov. General
 information may also be obtained from
 the EPA Safe Drinking Water Hotline.
 Callers within the United States may
 reach the Hotline at (800) 426-4791.
 The Hotline is open Monday through
 Friday, excluding Federal holidays,
 from 9 a.m. to 5:30 p.m. Eastern Time.
 SUPPLEMENTARY INFORMATION:

Table of Contents
I. General Information
  A. Does this Notice Apply to My Public
   Water System?
                 B. How Can I Get Copies of Related
                   Information?
                 1. Docket
                 2. Electronic Access
               II. Background
                 A. What Is the Statutory Requirement for
                   the Six-Year Review?
                 B. What Has the Agency Done to Address
                   the Statutory Requirement?
               III. EPA's Current Revise/Not Revise
                   Decisions for the 69 Pre-1997 NPDWRs
               IV. Summary of Major Comments and New
                   Information and the Agency's Response
                 A. What Did Commenters Say Regarding
                   the Reasonableness and Appropriateness
                   of EPA's Six-Year Review Approach?
                 1. Overall Approach and Decision Criteria
                 2. Health Effects Technical Review
                 3. Analytical Methods Feasibility
                   Technical Review
                 4. Review of Treatment Technologies and
                   Related Issues
                 5. Review of Implementation-Related
                   Issues
                 6. Review of Occurrence and Exposure
                 7. Consideration of Available Economic
                   Information
                 B. What Comments or New Information
                   Did EPA Receive on Chemical
                   Contaminant-Specific Issues?
                 1. Alachlor
                 2. Antimony
                 3. Atrazine
                 4. Beryllium
                 5. Carbofuran
                 6. Chromium
                 7. 1,1-Dichloroethylene
                 8. Dichloromethane
                 9. Di(2-ethylhexyl)adipate (DEHA)
                 10. Di(2-ethylhexyl)phthalate (DEHP)
                 11. Fluoride
                 12. Glyphosate
                 13. Lead and Copper
                 14. Lindane (y-hexachlorocyclohexane)
                 15. Simazine
                 C. What Comments Did EPA Receive
                   Regarding the Review of
                   Implementation-Related Issues for
                   Chemical NPDWRs?
                 D. What Comments Did EPA Receive on
                   the Total Colifbrm Rule?
                 E. What Comments Did EPA Receive on
                   Research Needs?
               V. References

               List of Tables
               Table HT-1: Current Revise/Not Revise
                   Decisions for the 68 Chemical NPDWRs
                   and the TCR
               Table IV-1:1,1-Dichloroethylene Occurrence
               Table IV-2: Lindane Occurrence

               I. General Information

               A. Does This Notice Apply to My Public
               Water System?

                 This action itself does not impose any
               requirements on anyone. Instead, it
               notifies interested parties of the
               availability of EPA's responses to
               comments received  on EPA's Six-Year
               Review protocol and the Agency's
               current revise/not revise decisions for
               69 NPDWRs.
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-2002-0012. The official public
docket consists of the documents
specifically referenced in this action,
any public comments received, and
other information related to this action.
Although a part of the official docket,
the public docket does not include
Confidential Business Information (CBI)
or other information whose disclosure is
restricted by statute. 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 Ave., NW., Washington,
DC. The EPA Docket Center Public
Reading Room is open from 8:30 a.m. to
4:30 p.m., Monday through Friday,
excluding legal holidays. The telephone
number for the Public Reading Room is
(202) 566-1744, and the telephone
number for the Water Docket is (202}
566-2426.
2. Electronic Access
  You may access this Federal Register
document electronically through the
EPA Internet under  the "Federal
Register" listings at http://
www.epa .gov/fedrgstr/.
  An electronic version of the public
docket is available through EPA's
electronic public docket and comment
system, EPA Dockets. You may use EPA
Dockets at http://www.epa.gov/edocket/
to view public comments, access the
index listing of the contents of the
official public docket, and access those
documents in the public docket that are
available electronically. Although not
all docket materials may be available
electronically, you may still access any
of the publicly available docket
materials through the docket facility
identified in section I.B.1. Once in the
system, select "search," then key in the
appropriate docket identification
number.
Abbreviations and Acronyms Used in
This Action
BAT—best available technology
CBI—confidential business information
CCL—contaminant  candidate list
CFR—Code of Federal Regulations
CMR—Chemical Monitoring Reform
DACT—diaminochlorotriazine
DEA—desethyl atrazine
DEHA—di(2-ethylhexyl)adipate
DEHP—di(2-ethylhexyl)phthalate
DIA—desisopropyl  atrazine
EPA—United States Environmental
  Protection Agency

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                       Federal  Register/Vol. 68, No.  138/Friday, July 18,  2003/Notices
                                                                    42909
EPA/DC—EPA Docket Center
FQPA—Food Quality Protection Act
FR—Federal Register
IOC—inorganic chemical
IRED—interim reregistration eligibility
  decision
IRIS—Integrated Risk Information
  System
LCCA—Lead Contamination Control Act
  of 1988
LCR—Lead and Copper Rule
MCL—maximum contaminant level
MCLG—maximum contaminant level
  goal
MDL—method detection limit
mg/kg/day—milligram(s) per kilogram
  of body weight per day
mg/L—milligram(s) per liter
MYP—multi-year plan
NAS—National Academy of Sciences
NCOD—National Contaminant
  Occurrence Database
NDWAC—National Drinking Water
  Advisory Council
NPDWR—National Primary Drinking
  Water Regulation
NRC—National Research Council
NTP—National Toxicology Program
NTNCWS—non-transient non-
  community water system
Occurrence Methodology Document—
  Occurrence Estimation Methodology
  and Occurrence Findings  Report for
  the Six-Year Review of Existing
  National Primary Drinking Water
  Regulations
Occurrence Summary  Document—
  Occurrence Summary and Use
  Support Document for the Six-Year
  Review of Existing National Primary
  Drinking Water Regulations  *
OPP—Office of Pesticide Programs
OW—Office of Water
PE—performance evaluation
PHS—Public Health Service
PQL—practical quantitation level
Protocol Document—EPA Protocol for
  Review of Existing National Primary
  Drinking Water Regulations
RED—reregistration eligibility decision
RfD—reference dose
ROS—regression on ordered statistics
RSC—relative source contribution
SAB—Science Advisory Board
SAP—Science Advisory Panel
SDWA—Safe Drinking Water Act
SOC—synthetic organic chemical
TCR—Total Coliform Rule
TMDLs—total maximum daily loads
Treatment Feasibility Document—Water
  Treatment Technology Feasibility
  Support Document for Chemical
  Contaminants; In Support of EPA Six-
  Year Review of National Primary
  Drinking Water Regulations
TT—treatment technique
VOC—volatile organic chemical
WQP—water quality parameter
WS—water supply
H. Background

A. What Is the Statutory Requirement
for the Six-Year Review?
  Under the Safe Drinking Water Act
(SDWA), as amended in 1996, EPA must
periodically review existing National
Primary Drinking Water Regulations
(NPDWRs) and, if appropriate, revise
them. Section 1412(b)(9) of SDWA
states:
  The Administrator shall, not less often
than every 6 years, review and revise, as
appropriate, each national primary drinking
water regulation promulgated under this title.
Any revision of a national primary  drinking
water regulation shall be promulgated in
accordance with this section, except that
each revision shall maintain, or provide for
greater, protection of the health of persons.

B. What Has the Agency Done To
Address the Statutory Requirement?
  The Agency developed a systematic
process, or protocol, for the review of
existing NPDWRs in accordance with
the SDWA requirements and applied the
protocol to the review of the NPDWRs
for total coliforms and 68 inorganic and
organic chemicals published prior to the
SDWA 1996 Amendments (i.e., pre-1997
NPDWRs). In the April 17, 2002,
Federal Register, EPA provided:
  • A description of the review
protocol;
  • A detailed discussion of how the
protocol was applied in assessing each
of the 69 pre-1997 NPDWRs;
  • The preliminary results of each of
the technical reviews, and the
preliminary decision for each NPDWR;
and
  • A request for the public to  comment
on any aspect of the Agency's protocol
and preliminary decisions.
  Please refer to the April 17, 2002,
Federal Register for the detailed
discussion of EPA's revise/not revise
decisions for each of the 69 NPDWRs.
Today's action briefly summarizes the
major public comments, other new
information, and EPA's current revise/
not revise decisions for the 69 NPDWRs.
Today's action only discusses in detail
those decisions or rationales that were
affected by public comments or other
new information that has become
available since April 2002.
  In June 2002, EPA consulted  with the
Science Advisory Board (SAB) Drinking
Water Committee and requested their
review and comment on whether the
protocol EPA developed based  on the
National Drinking Water Advisory
Council (NDWAC) recommendations
was consistently applied and
appropriately documented. The SAB
provided verbal feedback regarding the
transparency and clarity of EPA's
decision criteria for making its revise/
not revise decisions under the current
review. EPA has revised this protocol
document to better explain how the
decision criteria were applied and will
also take the SAB comments into
consideration when planning for the
next review cycle,

III. EPA's Current Revise/Not Revise
Decisions for the 69 Pre-1997 NPDWRs
  EPA received comments from 44
commenters on its preliminary  revise/
not revise decisions in the April 17,
2002, Federal Register. The Agency
responded to these comments in the
"Public Comment and Response
Summary for the Six-Year Review of
National Primary Drinking Water
Regulations" (USEPA, 2003e), which is
available in the Water Docket in the
EPA Docket Center and at the EPA
Dockets Web site http://www.epa.gov/
epadocket/. Other technical support
documents * for the decisions discussed
in today's action are also available in
the Water Docket and at the EPA
Dockets Web site http://www.epa.gov/
epadocket/ and the Safewater Web site
http://www.epa.gov/safewater/.
  Based on the Agency's preliminary
review, as well as the public comments
received and other new information,
EPA believes that it is appropriate to
revise the Total Coliform Rule (TCR).
The Agency also believes that it is not
appropriate to revise the 68 chemical
NPDWRs at this time. However, for the
reasons discussed in.sections IV.B.7,
IV.B.13, andIV.B.14 of today's  action,
the Agency has modified the basis of its
not revise findings for 1,1-
dichloroethylene, lead, and lindane,
respectively. Table HI-1 reflects the
Agency's current revise/not revise
decisions for the 69 NPDWRs. As
indicated in Table ffi-l, EPA's  decision
not to revise an NPDWR at this time is
based on one of the following reasons:
  • Health risk assessment is in
process: As of December 31, 2002, the
Agency is currently conducting, or has
scheduled, a detailed review of current
health effects information. Because the
results of the assessment are not yet
available, or were not available in time
for consideration under the 1996-2002
review cycle, the Agency does not
believe it is appropriate to revise the.
NPDWR at this time.  In these cases, EPA
will consider the results of the updated
  1 These include: (1) EPA's overall protocol for the
review of NPDWRs (USEPA, 2003c); (2] health
effects (USEPA, 2003f); (3) analytical methods
feasibility (USEPA, 2003a); (4) treatment technology
(USEPA, 2003g); (5) consideration of other
regulatory revisions (USEPA, 2003b); (6) occurrence
and exposure (USEPA, 2003d; USEPA, 2002f); (7)
and economic considerations (USBPA, 2Q02c).

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Federal Register/Vol. 68, No. 138/Friday, July 18, 2003/Notices
health risk assessment during the 2002-
2008 review cycle. If the results of the
health risk assessment indicate a
compelling reason to reconsider the
maximum contaminant level goal
(MCLG), EPA may decide to accelerate
the review schedule for that
contaminant's NPDWR.
  • NPDWR remains appropriate after
data/information review: The outcome
of the review indicates that the current
regulatory requirements remain
appropriate, and therefore, no regulatory
revisions are warranted. Any new
information available to the Agency
               either supports the current regulatory
               requirements or does not justify a
               revision.
                 • New information, but no revision
               appropriate at this time because:

               —Low priority: hi EPA's judgment, any
                 resulting revisions to the NPDWR
                 would not provide a meaningful
                 opportunity for health risk reduction
                 or result in meaningful cost-savings to
                 public water systems and their
                 customers.  These revisions are a low
                 priority activity for the Agency and,
                 thus, are not appropriate for revision
  at this time because of one or more of
  the following considerations:
  competing workload priorities; the
  administrative costs associated with
  rulemaking; and the burden on States
  and the regulated community to
  implement any regulatory change that
  resulted.
—Information gaps: Although results of
  the review support consideration of a
  possible revision, the available data
  are insufficient to support a definitive
  regulatory decision at this time.
BILLING CODE 6560-50-P

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                      Federal Register/Vol.  68, No.  138/Friday, July 18,  2003/Notices
42911
Table TTT-1 : Current Revise/Not Revise Decisions for the 68 Chemical NPDWRs and the TCR
Not
Appropriate
for Revision
at this Time
Candidate
for Revision
Risk assessment in process ':
chemical currently undergoing
an EPA health risk assessment;
includes the three initiated as a
result of this review
(34 NPDWRs)
NPDWR remains appropriate
after data/information review
(16 NPDWRs)
New
information, •
but no
revision
appropriate
because:
Low priority
(14 NPDWRs)
Information
gaps
(4 NPDWRs)
Based on review of "other
regulatory revisions"
(1 NPDWR)
Acrylamide Diquat
Alachlor Endothall
Antimony Ethylbenzene
Asbestos Ethylene dibromide
Atrazine Glyphosate
Benzojajpyrene " Methoxychlor
Cadmium Pentachlorophenol
Carbofuran Polychlorinated biphenyls
Carbon tetracbloride Simazine
Copper ' Styrene
Cyanide 2,3,7,8-TCDD pioxin)
2,4-D (2,4-Dichlorophenoxyacetic acid) Tetrachloroethylene
1,2-Dichlorobenzene Thallium
1,4-DichIorobenzene Toluene
1 ,2-Dichloroethane 1,1,1 -Trichloroethane
Di(2-cthylhexyl)adipate Trichloroethylene
Di(2-ethy]hexyl)phtbalate Xylenes
Barium Mercury
Dalapon Monochlorobenzene
cis-1 ,2-DIchloroctbyIeae Nitrate
trans- 1,2-DichloroethyIene Nhrite
Dinoseb Selenium
Endrln 2,4,5-TP (Silvex)
Epichlorohydrin 1,2,4-TrichIorobenzene
Hexachlorocyclopentadiene Vinyl chloride
Senzene Heptachlor epoxide
Beryllium " Hexachlorobenzene
Chlordane Lindane
l,2-Dibromo-3-chloropropane OxamyJ
1,1-DichloroethyIene Picloram
1 ,2-Dichloropropane Toxaphene •
Heptachlor 1 , 1 ,2-Trichloroethane
Chromium Fluoride
Dichioromethane Lead
Total Colflbrm Rule (TCR)
1 As of December 3!, 2002, the Agency is currently conducting, or has scheduled, a detailed review of current health effects
information.
                                                    12
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IV. Summary of Major Comments and
New Information and the Agency's
Response
  This section summarizes the major
public comments, including the
Agency's response, and other new
information, and explains any
modifications to EPA's preliminary
revise/not revise decisions. For a more
detailed summary of the comments and
the Agency's response, please refer to
the document: "Public Comment and
Response Summary for the Six-Year
Review of National Primary Drinking
Water Regulation" (USEPA, 2003e).

A. What Did Commenters Say Regarding
the Reasonableness and
Appropriateness of EPA's Six-Year
Review Approach?

1. Overall Approach and Decision
Criteria
  a. Adequacy of the Review.
Commenters generally agreed that EPA
had identified the appropriate key
elements of the review. However, some
commenters stated that the Agency
could have done more in some areas
(e.g., implementation) and a few
commenters expressed the opinion that
the Agency's review process contains
weaknesses, or was not applied
appropriately, because it did not
identify any chemical NPDWRs for
revision at this time.
  EPA Response: The Agency believes
that its basic review protocol and
decision rationale are reasonable and
appropriate. Even though EPA's
application of the protocol did not
identify any chemical NPDWRs for
revision at this time, that is not a reason
to reject or modify the protocol. The
review did result in the initiation of
health risk assessments for three
contaminants and efforts to address data
gaps/research needs for several other
contaminants. Health risk assessments
are underway for approximately half of
the chemical contaminants addressed in
today's action. The Agency expects most
of these assessments to be completed
within the next few years. When
completed, these assessments will
support further analysis  that may result
in different revise/not revise decisions
as part of the ongoing Six-Year Review
process.
  b. Criteria for Deciding that an MCLG/
MCL Revision is Appropriate and
Definition of "Significant" and
"Negligible." While some commenters
agreed, others disagreed with the
Agency's consideration of estimated
changes in occurrence levels and
available economic information
whenever a health or technological basis
exists to revise a standard. For example,
                some commenters felt that EPA should
                revise the MCLG and, as appropriate,
                the maximum contaminant level (MCL),
                whenever a health basis exists,
                regardless of other considerations. A
                few commenters criticized the Agency
                for not defining what it considers
                "significant" and "negligible" gains in
                public health protection and/or cost-
                savings in terms of regulatory revision.
                  EPA Response: Section 1412(b)(9) of
                SDWA, as amended in 1996, provides
                the Administrator with broad discretion
                to determine when a revision to an
                NPDWR is appropriate. As a part of this
                determination, the Agency believes it is
                reasonable to consider whether a
                potential revision is likely to provide a
                meaningful opportunity for health risk
                reduction. This criterion is consistent
                with the statutory provisions governing
                the regulatory determination process
                under section 1412(b)(l)(A) for
                contaminants not currently regulated.
                EPA also believes it is reasonable to
                consider die extent of potential cost-
                savings for public water systems and
                their customers when determining
                whether revisions that potentially
                would result in a relaxed standard  (i.e.,
                where a health basis exists for a less
                stringent standard) or streamlined
                implementation are appropriate. These
                considerations allow the Administrator
                to better prioritize efforts that are most
                likely to result in a meaningful
                opportunity for health risk reduction or
                cost-savings to public water systems and
                their customers. Revisions that do not
                satisfy at least one of these criteria  are
                a low  priority activity for the Agency,
                and thus are not appropriate at this time
                because of one or more of the following
                considerations:
                  •  Competing workload priorities;
                  •  The administrative costs associated
                with rulemaking; and
                  •  The burden on States and the
                regulated community to implement any
                regulatory change that resulted.
                  EPA believes that the determination
                of whether the impact of a potential
                revision is "significant" or "negligible"
                is a matter of judgment that depends on
                a number of variables, not all of which
                are amenable to precise definition.
                However, EPA recognizes that the use of
                "negligible/significant" terminology
                may imply more precision and
                quantitation in the determination than
                is possible. The Agency also
                understands that the use of the term
                "negligible" may imply to some  that the
                Agency is belittling small gains in
                health risk reduction. This is not the
                Agency's intent. Accordingly, in today's
                action, the Agency has explained its
                rationale more clearly in terms of the
                criteria noted in the previous paragraph.
  c. Authority to Relax an Existing
Standard and Deregulation of Low/Non-
Occurring Contaminants. Some
commenters argued that the Agency
should never consider relaxing a
standard because doing so, by
definition, would lessen the level of
public health protection. Other
commenters encouraged the Agency to
actively consider deregulating
contaminants that have low occurrence
or do not appear to be occurring in
finished water or, at a minimum, to
further reduce the frequency of
monitoring for these contaminants.
  EPA Response: EPA disagrees with
those commenters who oppose relaxing
a standard for any reason. The
legislative history of the SDWA
Amendments of 1996 makes clear that
Congress envisioned the possibility that
a relaxed standard might be appropriate
under circumstances that would not
result in a lessening of the level of
public health protection. In its
discussion of potential revisions to an
existing drinking water standard,  Senate
Report Number 104-169 (available
electronically at http://thomas.loc.gov/]
states:
  Amendments made by the bill require that
any future standard issued for a contaminant
already regulated must maintain or provide
for greater protection of the health of persons.
Generally, this will preclude the
promulgation of a revised standard for a
contaminant that is less stringent than the
standard already in place. However, there are
circumstances under which a standard may
be relaxed. The ma-rimnm contaminant level
goal for a contaminant is set at a level at
which there is no adverse effect on the health
of persons with an adequate margin of safety.
New scientific information may cause the
MCLG to be revised and in some cases these
revisions may be to less stringent levels. This
may lead to a revision of the maximum
contaminant level since it need be no more
stringent than the MCLG. New information
may also allow for a smaller margin of safety
because it narrows the range of uncertainty
for estimates of health risks. Finally, some
substances which have been regulated as
carcinogens for ingestion in drinking water
may be reclassified (as asbestos has been in
the most recent revision) or assigned a
threshold for the effect based on new
scientific information. In each of these cases,
EPA may issue a revised standard for a
contaminant that is less stringent than the
one it replaces.
(S. Rep.104-169,104th Cong., 1st Sess.
(1995) at 38)

  However, because section 1412 (b) (9)
of SDWA requires that any revision to
an existing NPDWR maintain or
improve the level of public health
protection, EPA believes that a clear,
technically-based demonstration

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                                                                    42913
regarding the absence of potential risk is
necessary to deregulate a contaminant.
EPA does not believe it is appropriate to
deregulate any currently regulated
contaminant at this time because the
Agency is not able to make a
determination, pursuant to section
1412(b)(9) of SDWA, that there would
be no lessening of public health
protection if the contaminant were
deregulated. The Agency disagrees that
evaluation of finished water data is
sufficient to consider deregulation  of
low or non-occurring contaminants. The
apparent low or non-occurrence of these
contaminants in finished water may be
the result of effective treatment
processes in place rather than the lack
of occurrence in source water.
  EPA believes that the existing waiver
provisions hi the SDWA regulations
give States sufficient flexibility to
reduce or potentially eliminate
monitoring of a chemical contaminant,
where appropriate. States that have
primacy for the drinking water
regulations are responsible for their
waiver programs and can grant waivers
if a particular pesticide or herbicide has
not been previously used,
manufactured, stored, transported, or
disposed in the area, a system's source
water is  not susceptible to
contamination from the chemical, or the
State has determined the system is not
vulnerable. The State can grant waivers
for individual contaminants, a group of
contaminants, or issue an area-wide
waiver (see 40 CFR 141.23  CD) and  (c),
and 141.24 (f)  and (h)). In addition,
States can adopt alternative monitoring
strategies as long as the approach is as
stringent as the Federal requirements
{USEPA, 1997b).
2. Health Effects Technical Review
   a. Contaminants Undergoing Health
Risk Assessments. A few commenters
raised issues with respect to the 36
chemical contaminants for which health
risk assessments were underway when
EPA published its preliminary revise/
not revise decisions in the April 17,
2002, Federal Register. In particular,
these commenters wanted to know the
process that EPA plans to follow to
review each NPDWR once the risk
assessment is completed, including
when that review would occur and
when an accelerated review would be
appropriate.
   EPA Response: Between April and
August 2002, the Agency completed
health risk assessments for 2 of the 36
contaminants: 1,1-dichloroethylene and
lindane. The results of those
assessments and the impact on the
Agency's revise/not revise  decisions are
discussed in sections IV.B.7 and
IV.B.14, respectively, of today's action.
NPDWRs for the remaining
contaminants for which health risk
assessments are in process will be
reviewed as a part of the 2002-2008
review cycle. However, if in the
Agency's judgment, a compelling reason
exists to revisit the "not revise"
decision sooner, EPA may accelerate the
review cycle for that NPDWR. hi
reviewing these regulations, EPA
expects to apply an approach consistent
with the protocol used for the current
review. That is, the Agency will
consider the same key elements and
apply the same basic decision tree for
making a revise/not revise decision. The
key elements of the review include
health effects technical review,
technology review, other regulatory
revisions review, and, if appropriate,
occurrence/exposure analyses and
consideration of available economic
information (see 67 FR19030 at 19038,
April 17, 2002 (USEPA, 2002s)).
  b. Other Issues Related to the Health
Effects Technical Review. One
commenter stated that the Agency risk
assessments underestimate risk because
absorption of chemicals through the
skin, lung,  and nose is not "adequately"
taken into account. Another commenter
encouraged the Agency to evaluate the
literature for potential reproductive and
developmental effects for chemicals
with zero MCLGs since risk
management strategies, such as
monitoring frequency or treatment
requirements, may be affected by such
information.
  EPA Response: EPA disagrees that the
Agency underestimates risk when
deriving MCLGs. The Agency  takes
multiple routes of exposure into account
by including a relative source
contribution (RSC) in its calculation of
an MCLG value. The RSC compares
exposure from air, food, and drinking
water and uses the data in allocating a
portion of the total exposure to drinking
water. When exposure data for the
chemical are not available, EPA assumes
that the RSC from  drinking water is 20
percent of the total exposure. This
allows 80 percent of the total exposure
to come from sources other than
drinking water, such as exposure from
food, inhalation, or dermal contact.
  EPA recognizes the possibility that
some chemicals with zero MCLGs may
also be of reproductive and/or
developmental concern. EPA is
investigating these endpomts and their
potential impact on monitoring
frequency or treatment requirements.
However, the Agency does not believe
the analysis can be completed during
the current review cycle without
significantly delaying the current revise/
not revise decisions. To the extent
possible, EPA will consider the results
of this analysis and any additional
information during subsequent Six-Year
Reviews.
3. Analytical Methods Feasibility
Technical Review
  Commenters generally supported the
Agency's approach of using
Performance Evaluation (PE) Water
Supply (WS) data and the 10 times
method detection limit (MDL)
multiplier to evaluate possible changes
in analytical feasibility for several of the
contaminants under this Six-Year
Review. A few commenters agreed that
the WS data are a valuable source of
information for evaluating
interlaboratory performance and for
developing practical quantitation levels
(PQLs). However, the same commenters
questioned whether the approach of
using PE WS data will be possible for
future reviews since the Agency's
laboratory  certification program that
once collected this information has been
externalized to private providers. These
commenters questioned whether the
externalized or privatized data would be
sufficient for the determination and/or
re-evaluation of PQLs. In addition, at
least one commenter suggested that it
may be appropriate (in the next Six-Year
Review) to re-evaluate the policy of
basing the  PQL on only EPA Regional
and State laboratory results, and
recommended that the Agency include
commercial and large utility laboratory
results. According to the commenter,
these laboratories (commercial and large
utility) have demonstrated "significant
innovation in method development and
improved quantitation."
   EPA Response: EPA agrees that the
WS studies have been a valuable source
of information for determining PQLs. At
this time, the Agency has not
 determined whether the privatized data
will be sufficient for the purposes
mentioned by the commenter. In
 addition, the Agency has not yet
 determined how best to gather data to
 determine and/or reassess PQLs for
 future reviews. The Agency is in the
 process  of evaluating acceptable
 options. The policy for determining the
most appropriate methodology for
 calculating PQLs for drinking water
 contaminants is outside the scope of the
 Six-Year Review.

 4. Review  of Treatment Technologies
 and Related Issues
   Commenters suggested that, while
 EPA's review of existing NPDWRs was
 generally consistent with the NDWAC
 recommendations to EPA (NDWAC,
 2000), the  Agency's review of treatment

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technologies which support the
regulations should be expanded.
Specifically, commenters recommended
that EPA review all treatment technique
{TT} requirements and allow for
changing or expanding these TT
requirements where new information
warrants such a change.
  EPA Response: EPA continues to
believe its approach to reviewing TT
requirements is appropriate. The "EPA
Protocol for the Review of Existing
NPDWRs" (Protocol Document)
discusses when it is appropriate for the
Agency to consider revisions to TT-type
regulations (see sections n.C and ni.B of
the Protocol documents) (USEPA,
2002d; USEPA, 2003c). The Agency
discussed the review of the four
chemical treatment technique NPDWRs
(i.e., acrylamide, copper,
epichlorohydrin, and lead)  in both the
draft and final  "Water Treatment
Technology Feasibility Support
Document for Chemical Contaminants;
hi Support of EPA Six-Year Review of
National Primary Drinking Water
Regulations" (Treatment Feasibility
Documents)  (USEPA, 2002b; USEPA,
2003g). The Agency has no specific
information that provides a basis for
revisions to TT requirements at this
time. However, EPA believes that
research data in a number of treatment-
related areas may be useful in future
reviews of NPDWRs. The Agency is
committed to working with stakeholders
to identify and prioritize treatment-
related research needs, and to work with
EPA's research partners to address the
highest priority needs.
5. Review of Implementation-Related
Issues
   While several commenters felt overall
that EPA's Six-Year Review protocol
was reasonable and appropriate, they
encouraged EPA to consider
implementation-related modifications
(i.e., "other regulatory revisions") as a
reason to revise a rule, even if there
were no basis to revise the MCLG and/
or MCL/TT requirements.
   EPA Response: Implementation-
related issues are the primary reason for
the Agency's decision to revise the TCR
at this time (67 FR19030 at 19085, April
17, 2002 (USEPA, 2002gJ), so it is clear
that EPA considered implemented-
related issues in its review. The Protocol
Document (USEPA, 2002d; USEPA,
2003c) identifies the conditions under
which the Agency will consider
implementation-related revisions. EPA
continues to believe these criteria are
appropriate. During the current review,
none of the identified potential
implementation-related revisions
pertaining to the chemical NPDWRs, in
               EPA's judgment, met the stated criteria
               for reasons documented in EPA's final
               document, "Consideration of Other
               Regulatory Revisions for Chemical
               Contaminants in Support of the Six-
               Year Review of National Primary
               Drinking Water Regulations" (USEPA,
               2003b).
               6. Review of Occurrence and Exposure
                  a. Occurrence Database Concerns. A
               few commenters asked for information
               regarding next steps for the National
               Contaminant Occurrence Database
               (NCOD). Another commenter pointed
               out that States have been willing to
               assist EPA by providing occurrence data
               beyond what is required of them.
               However, the commenter raised
               concerns that he/she felt EPA needs to
               address to facilitate further data sharing.
                  Some commenters expressed concern
               about the completeness and
               representativeness of the 16-State data
               set used for the Six-Year Review. One
               commenter suggested that the Agency
               should have issued an Information
               Collection Request to obtain more
               complete data for the Six-Year Review
               analysis.
                  EPA Response: The Agency is
               updating the NCOD to provide sample
               data that have been quality checked and
               used in various EPA analyses. This
               update to NCOD includes unregulated
               occurrence data collected prior to 1999
               as well as the latest Unregulated
               Contaminant Monitoring Rule data (64
               FR 50556, September 17,1999 (USEPA,
               1999b)) reported by laboratories for
               public water systems required to report
               results. It also includes tile data used for
               the Six-Year Review of regulated
               contaminants. EPA appreciates that
               some States are willing to share their
               full compliance monitoring records with
               the Agency, even though it is not
               required. The Agency and the States are
               continuing to work together to establish
               a protocol for data sharing, including
               safeguards to prevent misuse and
               misinterpretation of data.
                  The  16-State cross-section data set
               compiled for occurrence analyses for the
               Six-Year Review is the largest
               compliance monitoring data set for
               drinking water assembled by EPA to
               date. The design and construction of the
               16-State cross-section data set was based
               on the feet that contaminant occurrence
               varies spatially (geographically) due to
               differing patterns of population, land
               use, chemical use, geology, hydrology,
               and climate. The detailed description of
               the "pollution-potential" and
               geographic diversity considerations, and
               the derived balanced cross-section of
               States (that was developed to be
               collectively indicative of national
occurrence) is included in the
"Occurrence Estimation Methodology
and Occurrence Findings Report for the
Six-Year Review of Existing National
Primary Drinking Water Regulations"
(Occurrence Methodology Document)
(USEPA, 2003d). EPA selected its 16-
State cross-section to be as
representative as possible of national
contaminant occurrence. In EPA's
judgment, these States provide a
reasonable cross-section of agricultural
and industrial pollution potential, as
described in the Occurrence
Methodology Document, and also
provide geographic coverage of the
United States. Therefore, EPA believes
that the data assembled from these
States is the most representative data
currently available of national
contaminant occurrence.
  The Agency did receive occurrence
data from States other than those in its
16-State cross-section. However, many
State data sets contained incomplete
records (e.g., no water type or
population records specified) or had
other quality problems. Therefore, they
were not included in the analyzed data
set
  b. Occurrence Analysis Methodology.
One commenter noted that while the
occurrence estimation methodology has
several strengths, it also has a number
of flaws. The commenter was concerned
about the large proportion of non-
detected observations in the occurrence
data, and the difficulty of verifying the
assumptions made by the Agency. The
commenter agreed that EPA's
occurrence analysis  may represent a
"decent" estimate given the limitations
of the data. The commenter also noted
that the occurrence estimation
methodology is premised on "subjective
decisions or qualitative observations
* *  * rather than documented,
statistically-based quantitative ones"
and would like to have seen alternate
approaches used to provide
confirmation of the estimates. In
addition, the commenter questioned
why the Agency used "modeled data
sets to test the model rather than a
standard statistical strategy of basing the
model on a portion of the data set and
using the remainder to test the model."
  One commenter stated that the Stage
2 analysis (Bayesian analysis) was
poorly described and that this conflicts
with the transparency requirements of
the 1996 SDWA Amendments. In
addition, the commenter asked EPA to
clarify how the occurrence data from
other survey efforts, which are
summarized in "Occurrence Summary
and Use Support Document for the Six-
Year Review of Existing National
Primary Drinking Water Regulations"

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                                                                   42915
(Occurrence Summary Document)
(USEPA, 2002f), were used to inform the
modeling effort.
  EPA Response: EPA's occurrence
model development work was
significantly revised to reflect peer
review comments prior to the March
2002 Occurrence Methodology
Document (USEPA, 2002e) and the
April 17, 2002, Federal Register. The
additional work involved the
development of a detailed simulation
study to evaluate the Bayesian model.
EPA evaluated the performance of the
Bayesian estimator and an alternative
occurrence estimation approach, the
Regression on Ordered Statistics (ROS)
method, against synthetic data (i.e.,  data
developed with known national
contaminant occurrence distributions).
This simulation study also enabled an
explicit evaluation of the validity of the
assumption of a log-normal distribution
of the data.
  The simulation study was conducted
using varying conditions of a correctly
and incorrectly specified model, and
synthetic data sets developed with high
and low amounts of non-detected data.
The study findings indicated that the
Bayesian estimator performed well at
estimating the distributions of
contaminant concentration means
(especially in the upper tails),
performed better than the alternate
approach (i.e., the ROS method), and
accurately estimated the uncertainty of
the distributional estimates. The Agency
believes that this analysis supports the
validity of EPA's analytical approach.
The Bayesian model was tested against
the ROS approach because the ROS
method is an accepted drinking water
contaminant occurrence estimation
approach and was used to estimate
occurrence for the recent arsenic rule.
These findings were all included and
described in the Six-Year Review's
Occurrence Methodology Document.
  EPA has attempted to make its
occurrence analysis as clear as possible.
In response to the concerns raised by
the peer reviewers, a less technical
description of the occurrence estimation
methodology, aimed at the general
reader, was added to the main body of
the document. A detailed description of
the analysis, intended for readers with
technical expertise, including the
complete computer code used for model
analysis, was incorporated into an .
appendix of the document. EPA agrees
that its estimation methodology is
complex, but also believes that it is as
transparent as possible while still
providing a technically accurate
description of the Agency's analysis.
The use of simple national  occurrence
(statistical) assessments is not possible
at this time because there is no national
database with a complete collection of
regulated contaminant occurrence data.
Thus, there is no ideal basis for
comparison of national occurrence
studies (i.e.,.the true system
contaminant means and national
distributions of contaminant occurrence
are not, and cannot, be known). The
validation approach suggested by the
commenter (i.e., basing the model on a
portion of the data set and using the
remainder to test the model) is intended
for a regression-type of model using
observed system means to develop a
model for system-specific predictions.
This approach is not possible for the
six-year occurrence assessments, since,
to the best of EPA's knowledge, data on
the true individual system contaminant
mean concentrations and national
distributions are not available.
  Regarding the other survey studies
included in the Occurrence Summary
Document, few, if any, provide the
quantitative analytical results and
national, representative coverage that
would enable direct comparison to, or
inclusion in, the Six-Year Review
estimation analyses conducted with the
16-State cross-section occurrence data.
  c.  Other Issues Related to the
Occurrence Technical Review. One
commenter stated that the Agency's
current approach to  estimate
occurrence, employing a conservative
methodology and making conservative
simplifying assumptions in the absence
of definitive data, was appropriate. On
the other hand, the commenter argued
that  it was not appropriate for the
Agency to conduct as massive a data
collection and analysis project as was
undertaken without clear quantitative
objectives for the analysis identified a
priori. The commenter noted that it was
not apparent from either the April 17,
2002, Federal Register or the
Occurrence Methodology Document
(USEPA, 2002e) that the Agency
undertook an effort to set performance
objectives for the occurrence estimation.
  The commenter felt that the
Occurrence Methodology Document
does not allow the reader to determine
if the data are well apportioned among
the categories for which results are
reported. They also noted that they were
unable to find indications in the support
document that such an analysis was
undertaken in preparation for
constructing the Bayesian model. The
commenter stated that the support
document does not include actual
numeric counts or ranges of detected
values and suggested that it would be
useful to have this information by
contaminant, State, system size
category, and water type, as well as an
explicit count of non-detects by this
same matrix.
  EPA Response: There are several
general approaches when undertaking
and designing studies that require large
amounts of data. As the commenter
states, a priori data quality objectives
are part of one research approach where
study objectives (including technical
statistical performance measures) are
set, determinations are made on how to
meet those objectives, and then the
study is designed and implemented
accordingly. This ideal was not practical
for the national occurrence study
conducted for the Six-Year Review
because EPA did not have the resources
to generate original data, and was thus
dependent on the data that could be
obtained from the States. The approach
taken by the Six-Year Review was to
gather a large amount of data that, in
aggregate, was expected to be indicative
of national contaminant occurrence,
develop an occurrence estimation model
that built upon what has been learned
from recent regulatory development
work, and then evaluate how good the
resulting model estimates are.
  As  discussed in section IV.A.6.b of
today's action, the true national
distributions of contaminant occurrence
cannot be known. The 16-State national
cross-section data set.used for the Six-
Year Review is the largest compliance
monitoring database for drinking water
compiled by EPA to date. The database
represents approximately 37 percent of
the total number of public water
systems and 43 percent of the total
population served by public water
systems in the United States. External
peer reviews assessed the approach for
developing the national cross-section
and its "representativeness" separately
under the Chemical Monitoring Reform
(GMR) project (in 1998/1999) (USEPA,
1999c) and the Six-Year Review project
(USEPA, 2002e), and provided generally
favorable comments.
  The data management and cross-
section development have been
described in detail in the support
documents for the GMR and the Six-
Year Review. Further tabulations of the
data have been generated and presented,
as the commenter requested, in the final
Occurrence Methodology Document
(USEPA, 2003d). This information
includes the numbers and percentages
of analytical detections and non-
detections for each contaminant in each
of the system size and source water type
categories. Generally, because of the
large amount of data and the manner in
which the Bayesian model handles data,
the distribution of observations across
the various categories does not
significantly affect EPA's estimates. The

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number of analytical records differed by
contaminant. EPA evaluated 27,648 to
93,062 analytical records for the
individual inorganic chemicals, 32,606
to 121,327 records for the synthetic
organic chemicals, and 123,229 to
201,235 records for the volatile organic
chemicals. Most importantly, the Stage
2 occurrence model also quantifies the
uncertainty of the estimates in the
different categories of system size and
source water type. Hence, the statistical
significance of differences in occurrence
between the categories can be easily
assessed. However, the Agency believes
it is more appropriate to consider the
universe of potentially affected systems
within the 16-State cross-section, rather
than individual system categories, when
making its revise/not revise decisions as
part of the Six-Year Review process.

7. Consideration of Available Economic
Information
  Some commenters stated that, while
the Agency's review of NPDWRs was
generally consistent with NDWAC
recommendations to EPA (NDWAC,
2000), it is not clear how the Agency
took economic factors into account.
  EPA Response: An EPA
memorandum, dated March 18, 2002,
describes the Agency's qualitative
evaluation of economic factors (USEPA,
2002 c). This memorandum was cited in
the April 17, 2002, Federal Register and
is available in the docket for the Six-
Year Review (Docket No. OW-2002-
0012). It notes that detailed economic
analyses were not deemed by the
Agency to be necessary to support its
decisions of whether or not to revise a
particular NPDWR. Rather, a qualitative
assessment, based on the extent of
occurrence of a contaminant at the MCL,
as well as at alternative levels, was
undertaken to inform the Agency's
judgment about whether possible
changes to an MCL offered a meaningful
opportunity for health risk reduction
and/or cost-savings to public water
systems and then- customers. EPA has
conducted this assessment for 15 of the
chemical NPDWRs for which the
Agency had determined that a potential
health or technological basis may exist
for considering a revision to the MCLG/
MCL.2 EPA compared the estimated
occurrence and exposure values at the
current MCL and at potentially revised
regulatory level(s). For 14 of these
chemical NPDWRs, the Agency's
                assessment showed that the differences
                were small. In EPA's judgment, these
                differences are unlikely to provide a
                meaningful opportunity for health risk
                reduction or cost-savings to public
                water systems and then: customers.
                After consideration of these factors, EPA
                decided that any revision would be a
                low priority activity for the Agency,
                and, thus, not appropriate to revise at
                this time because of: Competing
                workload priorities; the administrative
                costs associated with rule making; and
                the burden on States and the regulated
                community to implement any regulatory
                change that resulted. In the case of
                dichloromethane, the Agency did not
                have sufficient data to recalculate the
                PQL to support any potential regulatory
                revision and thus placed it in the data
                gaps category.3
                B. What Comments or Ne\v Information
                Did EPA Receive on Chemical
                Contaminant-Specific Issues?

                1. Aiachlor
                  One commenter stated that the Office
                of Pesticide Programs (OPP) found that
                the chloroacetanilide pesticides
                (acetochlor, alachlor, and butachlor)
                should be considered as a group of
                chemicals having a common mechanism
                of toxicity  due to then1 ability to cause
                nasal turbinate tumors. The commenter
                believes EPA therefore should adopt a
                strong total chloroacetanilide pesticide
                standard that would strengthen the
                current standards.
                 EPA Response: Butachlor and
                acetochlor do not presently have an
                NPDWR and thus, are not included in
                the Six-Year Review. However,
                acetochlor is  included on the
                Contaminant Candidate List (CCL) and
                may in the future be considered as a
                candidate for regulation.  Alachlor is a
                regulated drinking water contaminant
                and is included in the Six-Year Review.
                It is currently undergoing a risk
                assessment and, therefore, the Agency
                believes that revision of the NPDWR is
                not appropriate at this time.
                 If the Agency decides to regulate
                either acetochlor or butachlor in the
                future, EPA may consider regulating
                them as a group, including alachlor,
                following a cumulative risk assessment
                process for pesticides that have a
  1 These 15 chemical NPDWRs are: Benzene;
beryllium; chlordane; l,2-dibtomo-3-
chloroproppane dichloromethane; 1,1-
dichloroethylene; 1,2-dichloropropane; heptachlor;
heptachJor, epoxide; hexachlorobenzene; lindane;
oxamyl; picloiam; toxaphene; and 1,1,2-
trichloroethane.
                 a The other three NPDWRs in the data gaps
               category, chromium, fluorida. and lead, were placed
               there for reasons other than occurrence and
               economic considerations. Chrominum is in the data
               gaps category because of the studies being
               conducted by the National Toxicology Program
               studies. Fluoride is in the data gaps category
               pending a National Academy of Sciences update of
               the health risk assessment and review of the RSC
               assumptions. Lead is in the data gaps category
               based on consideration of public comments (see
               section IV.B.13 of today's action).
common mechanism of toxicity. It
would be premature to propose a total
chloroacetanilide pesticide standard
until a cumulative risk assessment is
completed because this analysis could
impact the Agency's evaluation of
specific members of this group, or the
group as a whole.

2. Antimony
  a. Health Effects. A number of
commenters have suggested that the
current MCLG and MCL of 0.006
milligrams per liter (mg/L) for antimony
need to be revised. Some of the reasons
given were:
  • The study used to derive the
current MCLG (Schroeder et o/.,1970) is
not consistent with current good
laboratory practice guidelines and there
are several newer studies of antimony
toxicity that should be considered in
deriving a new reference dose (RfD).
  • Animals used in the Schroeder et
al., 1970 study had a viral infection. To
compensate for this infection,
adjustments were made to the size of the
animal groups in an attempt to salvage
the data.
  • The antimony compound used in
the Schroeder et al., 1970 study was
potassium antimony tartrate, the most
water soluble and toxic form of
antimony. Antimony found in drinking
water is likely to be in the form of less
toxic trivalent and pentavalent
antimony species. Therefore, basing the
MCLG on the most toxic species of
antimony (potassium antimony tartrate)
is likely to overestimate the risk posed
by antimony in drinking water.
  EPA Response: EPA agrees that the
MCLG and MCL for antimony may need
to be re-evaluated. EPA is in the process
of developing a new health risk
assessment for antimony, taking into
consideration new studies  that have
become available on the toxicity of
antimony. EPA expects to complete the
health risk assessment for antimony in
the 2003-2004 time frame (68 FR 5870,
February 5, 2003 [USEPA,  2003h)). As a
result of the ongoing health risk
assessment, a revision to the antimony
standard is not appropriate at this time,
and antimony will be re-evaluated as
part of the next Six-Year Review
process.
  b. Treatment and Implementation
Issues. Several commenters questioned
the appropriateness of the antimony
MCL, and the effectiveness of using the
EPA-designated best available
technologies (BATs) to meet the
antimony MCL. A few small systems in
Utah have levels of antimony in water
at or above the MCL value of 0.006 mg/
L. These systems were granted

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                                                                    42917
exemptions contingent upon testing and
installation of treatment by March 2004.
  These systems are investigating
treatment options for the removal of
antimony from their source water.
Commenters submitted supporting data
documenting the results of their testing
and cost analyses. According to
conunenters, on-site testing indicated
that the designated BATs (i.e., reverse
osmosis and coagulation/filtration) and
most of the other tested treatments were
ineffective and/or prohibitively
expensive due to: raw water quality
concerns; water conservation needs;
current costs for water production; and
other concerns, such as waste water
management. However, commenters did
identify treatment options that may be
feasible, but these may require further
investigation prior to full scale use.
  EPA Response: As discussed in the
April 17, 2002, Federal Register and as
noted in the previous response in
section IV.B.2.a, EPA does not believe it
is appropriate to consider revisions to
the NPDWR for antimony at this time
because of the ongoing health risk
assessment (67 FR 19030 at 19051
(USEPA, 2002g)).
  When EPA initially promulgated the
antimony NPDWR in 1992, the Agency
estimated that 200 public water systems
would be affected (USEPA, 1992). EPA
recognizes that implementation of this
standard may present challenges for a
few localities. Although the use of the
designated BATs for antimony may not
be appropriate in some cases, as long as
systems comply with the MCL, they are
not limited to these technologies.
  EPA believes that the treatment data
generated by the commenters may be
valuable and may provide insight into
potential alternative treatment
technologies. The Agency has revised
the document, "Water Treatment
Technology Feasibility Support
Document for Chemical Contaminants;
In support of EPA Six-Year Review of
National Primary Drinking Water
Regulations" (Treatment Feasibility
Document) (USEPA, 2003g) to refer to
these preliminary test data as they may
be applicable to the development of
potential new treatment technologies for
the removal of antimony and other
contaminants.

3. Atrazine
  a. Health Effects. Several commenters
addressed the EPA decision not to
consider revision of the MCL for
atrazine at this time. Some of these
commenters stated that EPA should use
the risk assessment, released by OPP hi
May 2002, as a basis for reconsidering
the atrazine NPDWR. One of the
commenters noted that the 2002 risk
assessment is based on reproductive and
developmental endpoints which
represents a change from the toxicity
endpoint that formed the basis of the
current MCLG. Two commenters stated
that the MCL for atrazine should be
revised upward because of the results of
the 2002 OPP risk assessment in which
the RfD increased and the cancer
classification changed from  "possible
human carcinogen" to "not  likely to be
a human carcinogen." The commenters
stated that the change in the cancer
assessment implies elimination of the
additional 10-fold risk management
factor used in 1991 to derive the MCLG/
MCL for atrazine. Another commenter
stated that atrazine should be regulated
using a non-linear approach which
recognizes that there is  a level at which
no known health effects occur and that
these findings must be part  of the new
MCL.
   Conversely, another commenter stated
that there is substantial new evidence
from epidemiological and occupational
studies that atrazine poses a serious
cancer risk, and that it is an endocrine
disrupter at low levels. The commenter
believes EPA should adopt  a revised
atrazine and total triazine standard
lower than (i.e., more stringent than) the
current 0.003 mg/L standard for
atrazine.
   A commenter also urged the Agency
to:
   * Provide a definitive timetable for.
review of the standard;
   • Outline a preliminary scope for its
review of the standard; and
   • State the underlying premise for the
scope of the review.
   Other commenters stated that the
existing NPDWR only regulates the
parent compound atrazine,  and that a
revised NPDWR should include the
chloro-metabolite degradants (i.e.,
diaminochlorotriazine  (DACT), desethyl
atrazine (DEA), and desisopropyl
atrazine (DIA)). These commenters
believe that inclusion of the chloro-
metabolites would strengthen
compliance monitoring programs for
public water systems under SDWA and
thereby strengthen public health
protection. They stated that a regulation
for atrazine and the chloro-metabolites
should be developed and promulgated
within the next 12 to 18 months.
Another commenter stated  that since the
Agency has found that atrazine,
simazine, propazine, and the degradants
DACT, DEA, and DIA have  a common
mechanism of toxicity, these should be
regulated in a total triazine  regulation.
   EPA Response: EPA does not believe
it is appropriate to consider revisions to
the NPDWR for atrazine at this time
because the revised risk assessment has
not been finalized. For purposes of the
Six-Year Review protocol, EPA
considers a risk assessment final when
an Interim Reregistration Eligibility
Decision (IRED), Reregistration
Eligibility Decision (RED), and/or IRIS
assessments are complete.4 Even though
an IRED for atrazine was signed on
January 31, 2003, an amended IRED is
scheduled to be released hi October
2003 which will include a Scientific
Advisory Panel (SAP) peer review of
new data related to health effects. Based
upon the outcome of the SAP review,
the October 2003 IRED may include
additional information that could
impact a revise/not revise decision.
Therefore, EPA does not believe it is
appropriate to consider possible
revisions to the NPDWR at this time.
  In reviewing the atrazine regulation,
EPA will apply an approach consistent
with the protocol used for the current
review. The Agency will consider the
same key elements (i.e., health effects
review, technology review, other
regulatory revisions review, and, if
appropriate, occurrence/exposure
analyses and consideration of available
economic information) and apply the
same basic decision tree for making a
revise/not revise decision.
  To address the issue of regulating the
triazines as a group, the Agency is
evaluating the unregulated triazines as
part of the CCL process. When the risk
assessment is completed for atrazine,
the Agency will consider whether or not
there are compelling reasons for
considering a revision to the atrazine
regulation or to wait until the risk
assessment for the triazines, which
considers issues of cumulative risk, is
finalized. EPA will use the CCL
regulatory determination process in
deciding whether the triazines should
be regulated as a group.
   b. Costs  of Treatment. Commenters
stated that the costs associated with not
revising the MCL are great. These
commenters are concerned that State
agencies will be required to develop
total maximum daily loads (TMDLs)
based on 303(d)5 listings resulting from
  4 The IRED is an intermediate decision for an
 individual pesticide that does not take into account
 cumulative risk issues for pesticides with a
 common mode of action. The RED does include
 cumulative risk. If an IRIS assessment is also in
 process when the IRED or BED is signed, EPA will
 make a case-by-case decision cm whether to wait for
 the IRIS assessment before considering possible
 revisions to the NPDWR.
  * Section 303(d) of the Clean Water Act and the
 implementing regulations (40 CFR 130.7) require
 States to develop TMDLs for waters where required
 point and nonpoint source pollution controls are
 not stringent enough to attain or maintain
 compliance with State water quality standards after
 the application of technology-based and other
                               Continued

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Federal Register/VoI. 68, No.  138/Friday,  July 18,  2003/Notices
an outdated MCL which creates a
burden on State and local government,
its citizens, and diverts limited
resources away from programs that
provide real benefits. Some commenters
also stated that the treatment costs to
hundreds of community water systems
are considerable. One commenter also
stated that these are real dollars that
would otherwise be available for
emergency services, education, nutrition
programs, and other vital programs that
are the responsibilities of local and State
agencies.
  EPA Response: As stated in the
previous response in section IV.B.S.a,
EPA does not believe it is appropriate to
revise the NPDWR for atrazine at this
tune because the risk assessment is not
yet final. If EPA decides to revise the
NPDWR for atrazine, economic factors,
including feasibility and an assessment
of costs and benefits, will be taken into
consideration for the drinking water
program.
4. Beryllium
  Two commenters believed that the
current drinking water standard for
beryllium is more stringent than
necessary for the protection of public
health and felt that EPA should adopt a
higher value for the beryllium standard.
These commenters disagreed with EPA
on the use of an uncertainty factor of
300 in deriving the 1998 RfD. The
commenters stated the use of
uncertainty factors of 3 for database
uncertainty, 10 for extrapolating data
from a dog study to humans, and 10 for
intraspecies variation is inappropriate.
The commenters stated that EPA has the
authority to raise the current drinking
water standards for beryllium based on
new information that allows for a
smaller margin of safety than the one
used by EPA. The commenter felt that
the current standard for beryllium is
"lower than necessary to protect the
public from beryllium toxicity and
results hi clean-up standards that are
lower than naturally occurring level of
beryllium hi water sources and soils."
This commenter also expressed concern
that the local application of the Federal
drinking water standard to private wells
in some cases caused undue concerns
among users of those wells.
  EPA Response: One of the purposes of
the Six-Year Review is to determine if
the MCL of a chemical should be
changed based on a revised RfD or
cancer classification. Analytical
methods and treatment technologies are
required controls. A TMDL establishes the
maximum amount of a pollutant that may be
introduced into a waterbody while still ensuring
attainment and maintenance of water quality
standards.
                considered, as well as occurrence in
                public water systems. The RfD for
                beryllium was revised in 1998 based on
                extensive Agency internal and external
                reviews, and is unlikely to be revised in
                the absence of new data. The 1998
                assessment also provided separate
                cancer classification for inhalation and
                oral exposures (USEPA, 1998). hi the
                revised assessment, the carcinogenicity
                of beryllium by the inhalation route was
                described as "likely," while that by the
                oral route of exposure "cannot be
                determined." As discussed hi the April
                17, 2002, Federal Register, the Agency
                considered the occurrence of beryllium
                at both potentially higher and lower
                regulatory levels. EPA concluded that a
                revision to the NPDWR would not result
                in a meaningful opportunity for health
                risk reduction or cost-savings to public
                water systems and then: customers. As
                a result, revision of this NPDWR is a
                low priority action for the Agency and
                is not appropriate at this time.
                 The goal of drinking water standards
                is to protect public health. Therefore, it
                does not matter whether the source of
                contamination is naturally-occurring or
                man-made. While EPA appreciates the
                information on private wells, the SDWA
                requirements do not apply to private
                wells (i.e., wells that are not part of a
                "public water system"). The costs and
                benefits of a drinking water standard are
                assessed only with regard to the impacts
                on public water systems and then-
                customers.
                5. Carbofuran
                 Some commenters mentioned that the
                Agency concluded that N-methyl
                carbamates, including carbofuran,
                should be considered  as a class because
                they have a common mechanism of
                toxicity. Therefore, they believe EPA
                should issue a stronger standard for
                total N-methyl carbamates, including
                carbofuran, which would be more
                stringent than the current carbofuran
                standard of 0.04 mg/L.
                 EPA Response: EPA is re-evaluating
                the toxicity of carbofuran. However, a
                final assessment has not been issued by
                EPA. The Agency considers N-methyl
                carbamate pesticides as a group of
                chemicals having a common mechanism
                of toxicity due to their ability to inhibit
                acetylcholinesterase. However, it is not
                appropriate to revise the NPDWR for
                carbofuran at this time because the
                Agency has not yet completed the final
                health risk assessment for carbofuran or
                the other N-methyl carbamates.

                6. Chromium
                 One commenter requested that EPA
                move quickly in making a revise/not
                revise determination once the new data
on chromium become available from the
National Toxicology Program (NTP)
studies of the health effects of
chromium VI.        	
  EPA Response: The NTP studies that
the commenter refers to should be
available before the end of the next Six-
Year Review cycle. Meanwhile, EPA is
continuing to follow the progress of
NTP in conducting subchronic and
chronic studies of chromium VI.6 NTP
made the data from the subchronic
portion of the study available to the
public in June 2002 (NTP, 2002). A peer
review meeting was held at NTP on July
24, 2002. EPA will examine the peer
review report covering the subchronic
data once it becomes available. Once the
subchronic and chronic studies are
completed, the health effects data will
be evaluated with regard to then: impact
on the present RfD and cancer
assessment, and integrated with the
occurrence and analytical method data
before making a new revise/not revise
decision.
7.1,1-Dichloroethylene
  In the April 17,  2002, Federal
Register, the Agency preliminarily
placed 1,1-dichloroethylene in the no
revision category because a health risk
assessment was pending at the time of
publication. Since the publication of the
April 17, 2002, Federal Register, the
Agency has finalized the risk
assessment for 1,1-dichloroethylene.
The remaining paragraphs in this
section include a brief background
discussion about the original
promulgation of the 1,1-
dichloroethylene NPDWR, the results of
the appropriate six-year technical
reviews and the Agency's revise/not
revise decision.
  a. Background. EPA published the
current NPDWR for 1,1-
dichloroethylene on July 8,1987 (52 FR
25690 (USEPA, 1987)). The NPDWR
established an MCLG and an MCL of
0.007 mg/L. The Agency based the
MCLG on an RfD of 0.009 milligram per
kilogram of body weight per day (mg/
kg/day) and a cancer classification of C,
possible human carcinogen.
  b.  Technical Reviews. EPA updated
the risk assessment for 1,1-
dichloroethylene on August 13, 2002
(USEPA, 2002i). The new risk
assessment established an RfD of 0.046
mg/kg/day, based  on the same
toxicologies! study as that of the MCLG,
but using an uncertainty factor of 100
  0 Since NTP is posting its progress on its internet
site http-J/ntp-serverjuehsJiih.gov/htdocs/Studies/
HexChromium/hexehromiiunpg.html, EPA and the
public will be able to evaluate the new data relative
to the existing EPA assessment for chromium VI as
it is released.

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                       Federal Register/Vol. 68, No.  138/Friday, July 18, 2003/Notices
                                                                    42919
instead of 1,000, and using benchmark
dose modeling for the dose-response
analysis. Under the 1986 cancer
guidelines (51 FR 33992, September 24,
1986 (USEPA, 1986)), 1,1-
dichloroethylene was assigned to Group
C, possible human carcinogen. Under
the draft revised "Guidelines for
Carcinogen Risk Assessment" (USEPA,
1999a), the data for 1,1-dichloroethylene
were considered inadequate for an
assessment of human carcinogenic
potential by the oral route.
  Based on the change in RfD for 1,1-
dichloroethylene, using a 20 percent
RSC and a 10-fold risk management
factor for possible carcinogenicity, EPA
used 0.03 mg/L as a level for evaluating
the occurrence data. Without the use of
the 10-fold risk management factor, EPA
also used 0.3 mg/L as a level for
evaluating the occurrence data.
  Analytical or treatment feasibility do
not pose any limitations for the current
MCL and would not be a limiting factor
at the 0.03 mg/L or the 0.3 mg/L level
(USEPA, 2002a; USEPA, 2003g). The
Agency's review of possible "other
regulatory revisions" did not identify
any issues that are specific to 1,1-
dichloroethylene (USEPA, 2003b).
  EPA evaluated the results of the
occurrence and exposure analyses for
1,1-dichloroethylene to determine
whether possible changes to the
standard would be likely to result in a
meaningful opportunity for cost-savings
to public water systems and their
customers (USEPA, 2003d). Table IV-1
shows the results of the detailed
occurrence and exposure analysis based
on the 16-State cross-section for the
current MCL (0.007 mg/L), and for two
higher levels (0.03  mg/L and 0.3 mg/L).
Based on the detailed analysis, it
appears that 1,1-dichloroethylene is
unlikely to occur at concentrations
above 0.007 mg/L in the States used for
the cross-section.
BILLING CODE 6560-SO-P

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Federal Register/Vol.  68, No. 138/Friday, July 18, 2003/Notices
Table IV-1: 14-Dichloroetbylene Occurrence1
Systems1
Level
(inmg/IO
Upper Level
Evaluated (without
10-fold risk 0.3
management
factor)'
Lower Level
Evaluated (with
10-fold risk 0.03
management
factor)3
Current MCL 0.007
16-State Cross-
Section -Total
Systems with Data
19,101
19,101
19,101
Estimated # of Systems
> Level Evaluated
(credible intervals)1-*
0 (0-0)
0 (0-0)
3 (1-6)
Estimated % of Systems
> Level Evaluated
(credible intervals)3
0.000% (0.000% - 0.000%)
0.000% (0.000% - 0.000%)
0.0144% (0.0051 8% - 0.03 1 1%)
Population Served by Systems1
Level
(in rag/L)
Upper Level
Evaluated (without
10-fold risk 03
management
factor)4
Lower Level
Evaluated (with
10-fold risk 0.03
management
factor)1
Current MCL 0.007
16-State Cross-
Section - Total
Population Served
by Systems with
Data
106,607,600
106,607,600
106,607,600
Estimated Population
Served by Systems
> Level Evaluated
(credible intervals)3
0 (0-0)
0 (0-0)
14,400 (0-136,900)
Estimated % of Population
Served by Systems
> Level Evaluated
(credible intervals)3
0.000% (0.000% - 0.000%)
0.000% (0.000%- 0.000%)
0.0135% (0.0000328% - 0.128%)
Notes:
1 Results are based on the number and percent of systems (and die corresponding population served by those systems) with estimated
mean concentrations above the specified level of evaluation.
1 All percentages are shown to three significant figures. All system values are rounded to the nearest whole system. All population
values are rounded to the nearest hundred.
1 "Credible intervals" are generated to quantify the uncertainty around each estimated probability in the Bayesian analysis of the
occurrence data. For further explanation of credible intervals and the Bayesian analysis, please see "Occurrence Estimation
•fclhodology and Occurrence Findings Report for the Six-Year Review of Existing National Primary Drinking Water Regulations"
USEPA, 2003d).
4 Based on the change in the RfD and a 20 percent RSC.
J Based on the change in the RfD, a 20 percent RSC, and a risk management factor of 10,
6 This value does not necessarily reflect the number of systems out of compliance' wilt the current MCL, because these data were
collected over the 1993-1997 time period, and because the value represents the estimated mean value over that time period, not the
running quarterly average on which compliance is based.
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                                                                   42921
  The results of the detailed occurrence
and exposure analysis indicate that less
than 0.02 percent of the 19,101 systems
sampled in the 16-State cross-section,
and less than 0.02 percent of the
population served by those 19,101
systems might be affected if EPA were
to consider levels as high as 0.03 mg/L
to 0.3 mg/L. The current BATs and
small system compliance technology for
1,1-dichloroethylene have other
beneficial effects [e.g., reduction of
other co-occurring contaminants, or
other common impurities) in addition to
1,1-dichloroethylene removal.
Therefore, if EPA were to consider any
of these higher levels, the Agency does
not know how many of these public
water systems that are currently treating
to comply with the current MCL of
0.007 mg/L would be likely to
discontinue treatment that is already in
place (USEPA, 2002c; USEPA, 2003g).
  c. Current Decision. Although there
are new health effects data that might
support calculation of a less stringent
standard for 1,1-dichloroethylene, EPA
does not believe a revision to the
NPDWR for 1,1-dichloroethylene is
appropriate at this time. In making this
decision, the Agency considered
whether any potential revision to the
1,1-dichloroethylene NPDWR is likely
to provide a meaningful opportunity for
cost-savings to public water systems and
then1 customers. After consideration of
this factor, EPA has decided that any
revision to 1,1-dichloroethylene would
be a low priority activity for the Agency,
and, thus, is not appropriate to revise at
this time because of:
  • Competing workload priorities;
  • The administrative costs associated
with ruiemaking; and
  * The burden on States and the
regulated community to implement any
regulatory change that resulted.
8. Dichloromethane
  One commenter stated that it may be
difficult to lower the PQL for
dichloromethane below the range of
0.001 to 0.002 mg/L since it is required
in a number of EPA methods and
therefore is a common laboratory
contaminant. Because it is a common
laboratory contaminant, the commenter
stated that using the MDL for 524.2 and
502.2 does not constitute a reasonable
basis for assuming that the PQL can be
lower. The commenter stated that none
of the existing WS studies had spike
samples this low and, in addition, the
occurrence data may have been
compromised due to laboratory
contamination.
  EPA Response: The basis for EPA
indicating that  a lower PQL "may exist"
was due to the fact that laboratories had
greater than 95 percent laboratory
passing rates using a +/—40 percent
acceptance window at "known" spike
concentrations close to current MCL of
0.005 mg/L. If laboratory contamination
due to dichloromethane were a problem,
such high passing rates at this value
would not be expected. The MDLs for
524.2 and 502.2 were only used with the
10 times MDL multiplier to estimate
what the lower value could be.
However, EPA does agree that, at this
time, the Agency does not have
sufficient data to recalculate the PQL for
dichloromethane and for this reason, the
Agency placed it in the data gap
category.
  Regarding the occurrence issue, EPA
has no data to suggest that high
occurrence values were due to false
positives from laboratory contamination
and the Agency is proceeding on the
assumption that State data are accurate
unless there is information to the
contrary.  If laboratory contamination
due to dichloromethane does exist,
laboratories should be able to identify
and discern a contamination issue if
they are running laboratory blanks.

9. Di[2-ethylhexyl)adipate (DEHA)
  One commenter submitted  detailed
comments regarding di(2-
ethylhexyl)adipate (DEHA). The
commenter believed that EPA should
consider removing the regulation for
DEHA and provided the following
reasons:
  • The regulation of DEHA in drinking
water does not provide any meaningful
reduction in the health risk to humans
because it is unlikely to cause adverse
effects to humans, including
reproductive effects, except at very high
doses which cannot be attained in
drinking water, due to the low water
solubility of DEHA.
  • The weight of evidence indicates
that the peroxisome proliferation
mechanism of DEHA rodent
carcinogenicity is not relevant to
humans. Thus, the MCLG for DEHA
should not include an additional 10-fold
risk management factor for possible
carcinogenicity.
  • The legislative history of the 1996
SDWA indicates that Congress
envisioned circumstances where
relaxation of an MCL would provide the
same level of health protection as the
existing regulation. Accordingly, if
DEHA cannot be deregulated, the
commenter believes the MCLG and MCL
should be increased.
  EPA Response: DEHA was regulated
in 1992. Since that time, new studies
have become available on the toxicity of
DEHA and its metabolites. For this
reason, EPA decided to initiate a new
health risk assessment of DEHA (67 FR
1212, January 9, 2002 (USEPA, 2002a)).
The assessment will include
examination of the studies on which the
current NPDWR is based, as well as an
evaluation of the data provided by this
commenter and new studies that have
become available since DEHA was
regulated. This health risk assessment is
planned for completion in the 2003-
2004 time frame (68 FR 5870, February
5, 2003 (USEPA, 2003h)) and is
expected to include development of an
RfD for non-cancer health effects, as
well as an assessment of potential
carcinogenicity from oral exposure. At
this time, it is premature to predict the
outcome of the Agency's assessment.
Thus, as discussed in section IV.A.2.a of
today's action, the Agency believes that
revision to the NPDWR for DEHA is not
appropriate at this time. EPA'will
determine in the future if revision of the
MCLG/MCL is warranted. Any revision
to the MCLG/MCL will also take into
consideration all the new information,
including the water solubility of DEHA
under various environmental
conditions.
  As stated by the commenter, the
legislative history of the 1996 SDWA
Amendments supports EPA's
interpretation that the Agency could
increase an MCLG and MCL as long as
the relaxed standard does not lessen the
level of public health protection.
However, EPA does not believe, at the
present time, that it can demonstrate
that deregulating DEHA would maintain
the current level of public health
protection (see section IV.A.1.C of
today's action).

10. Di(2-ethylhexyl)phthalate (DEHP)
  The same commenter who submitted
comments on DEHA also submitted
detailed comments regarding di(2-
ethylhexyljphthalate [DEHP). The
commenter felt that EPA should
consider removing the regulation for
DEHP for a variety of reasons, including
the following:
  • The regulation of DEHP in drinking
water does not provide any meaningful
reduction in the health risk to humans.
  • The weight of the evidence
indicates that the mode of action
through which DEHP causes cancer in
rodents is not relevant to humans and,
thus, the MCLG for DEHP should not be
zero. Any MCLG for DEHP should be
based on a threshold endpoint and not
on cancer. The commenter cited the
February 2000 International Agency for
Research on Cancer reclassification of
DEHP from Group 2B (possibly
carcinogenic to humans) to Group 3 (not
classifiable  as to its carcinogenicity to
humans) as justification for
recommending that EPA also reconsider
its cancer classification.

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Federal Register/Vol.  68,  No. 138/Friday,  July 18,  2003/Notices
  • The solubility of DEHP in drinking
water is well below any concentrations
that would pose a risk to humans.
  • If DEHP were to be considered for
regulation under the statutory
requirements of the 1996 SDWA, it
would not be regulated.
  • The legislative history of the 1996
SDWA indicates that Congress
envisioned circumstances where
relaxation of an MCL would provide the
same level of health protection as the
existing regulation. Accordingly, the
commenter believes consideration
should be given to increasing the MCLG
for DEHP based on the new health
effects data.
  • Reproductive effects from DEHP as
observed in rodents do not appear to be
relevant for primates and the doses that
are associated with effects in animals
are well above those that would be
experienced for humans exposed
through drinking water because of
solubility limitations. The commenter
also highlighted the findings of the NTP
Center for the Evaluation of Risk to
Human Reproduction that there was
"minimal concern for reproductive or
developmental toxicity for the general
population, based on estimates of total
exposure to DEHP."
  EPA Response: Revision of the
NPDWR for DEHP is not appropriate at
this time because an Agency health risk
assessment is currently in process. The
assessment is anticipated to be
completed in the 2003-2004 time frame
(68 FR 5870, February 5, 2003 (USEPA,
2003h)). Advances in understanding
differences between the primate and
rodent response to DEHP and the body
of toxicological data that have become
available in the past decade motivated
the Agency's re-examination of DEHP
and will be fully considered in the
reassessment.
  Once the Agency assessment is
completed, EPA will consider the
findings and will determine if there is
a compelling reason to review the DEHP
NPDWR prior to the next Six-Year
Review cycle. As discussed in sections
IV.A.l.b and IV.A.2.a of today's action,
"revise" versus "not revise" decisions
under the Six-Year Review take into
consideration occurrence, advances in
analytical methods, treatment
technologies, available economic
information, and other factors.
  As stated by the commenter, the
legislative history of the 1996 SDWA
Amendments supports EPA's
interpretation that the Agency could
increase an MCLG and MCL as long as
the relaxed standard does not lessen the
level of public health protection.
However, EPA does not believe, at the
present time, that it can demonstrate
               that deregulating DEHP would maintain
               the current level of public health
               protection (see section IV.A.l.c of
               today's action).
               11. Fluoride
                 EPA received three comments on the
               Agency's decision to place fluoride in
               the data gap category while the National
               Academy of Sciences (NAS) examines
               the toxicological and RSC data
               published over the last decade. Two of
               the commenters supported EPA's
               decision. One of these requested that the
               NAS concentrate its review on all of the
               data on the toxicology of fluoride and
               not just data on the critical skeletal
               effects. A third commenter requested
               that EPA not lower the MCL for fluoride
               from 4 mg/L to 2 mg/L and supported
               the 1986 EPA decision that dental
               fluorosis is a cosmetic effect rather than
               an adverse health effect. The commenter
               stated that the Public Health Service
               (PHS) recommended fluoridation level
               to be used at schools is 3 mg/L. The
               commenter also stated that if EPA were
               to lower the MCL, then schools that are
               currently fluoridating might have a
               conflict with the PHS recommendations
               and the EPA MCL.
                 EPA Response: The National Research
               Council (NRG) of the NAS has agreed to
               review the toxicological data on fluoride
               that have been published since it
               completed the 1993 study of "Health
               Effects of Ingested Fluoride" (NRC,
               1993), and to examine the data on
               relative fluoride exposure from drinking
               water compared to fluoride exposure
               from the diet and fluoride-containing
               dental products. Although the Agency
               indicated in the April 17, 2002, Federal
               Register that new data on bone effects
               were  a reason for initiating the data
               review (because bone effects were the
               basis  of the present MCLG), the NAS
               review will look at the new
               toxicological data for all endpoints. It is
               anticipated that the NAS review will
               take about two years to complete.
               Because of this pending review, revision
               of the NPDWR for fluoride is not
               appropriate at this time.
                 It is therefore premature to make any
               judgment regarding the NAS findings
               and whether or not they may lead to a
               consideration of a change in the MCL.
               However, PHS recommendations for
               school fluoridation programs are
               designed to provide the benefits of
               fiuoridation without increasing the risk
               for dental fluorosis. The PHS
               recommends school water fluoridation
               only if:
                 • The school has its own source of
               water;
                 • The school is not connected to a
               community water system;
  • More than 25 percent of students
are not served by a public water system
that provides water at levels adequate to
protect against dental caries; and
  • The students served are
kindergarten age or greater.

12. Glyphosate
  Two commenters made the statement
that, despite continued use of
glyphosate in pesticide applications,
available data and the Agency's
occurrence analysis, which includes a
prediction of frequency of occurrence at
levels below detection, indicate that
glyphosate is not observed in
compliance monitoring. One of these
commenters stated that the occurrence
appeared to be rare (less than 0.1
percent) at concentrations 1,000 times
lower than the MCL. Li addition,
according to the commenters, the cost of
analyzing for glyphosate is  expensive,
since it is a single analyte analysis.
Accordingly, the commenters wanted
EPA to reconsider the glyphosate
standard taking costs and benefits into
account. The commenters felt that the
data may indicate that a glyphosate
standard is inappropriate and does not
result in any additional public health
protection. Therefore, the commenters
recommended EPA pursue data gaps
that the Agency would need to fill in
order to demonstrate that eliminating
the glyphosate standard would not
lower public health protection.
  EPA Response: EPA is conducting an
Agency risk assessment for glyphosate
that will update the 1993 OPP
assessment. As a part of this process,
EPA is considering all the data that have
been published or submitted to EPA
since the completion of the RED in 1993
(USEPA, 1993). Accordingly, revision of
the glyphosate NPDWR is not
appropriate at this time due to the
pending Agency assessment.
  EPA recognizes that some utilities feel
that the analysis of glyphosate in
Hi-inking water is expensive and that
this should be taken into consideration
with respect to cost and benefits. This
will be considered when EPA evaluates
glyphosate in the next review cycle
(unless there is a compelling reason to
evaluate glyphosate on an accelerated
schedule). For the reasons stated in
section IV.A.1.C of today's action, EPA
does not believe it is appropriate to
consider deregulation of glyphosate at
this time.

13. Lead and Copper
   a. Research Needs. Three commenters
acknowledged the Agency's January
2000 revisions to the Lead  and Copper
Rule (LCR) but stated that the Agency
should continue to consider how to

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                                                                   42923
make the LCR easier to implement. In
particular, they recommended that the
following three LCR-related research
areas be incorporated into EPA's overall
research strategy:
  1. How well LCR monitoring results
correlate to actual exposure and the
effectiveness of the rule in protecting
public health.
  2. Whether there is a correlation
between water quality at indoor and
outdoor taps.
  3. What effect the ban on lead in
fixtures has had on lead levels and
whether changes need to be made based
on this ban.
  The commenters explained then-
rationale for recommending that the
Agency determine if a correlation could
be established between indoor and
outdoor water quality. They stated that
a major weakness of the LCR  is that
sample integrity may be compromised
by allowing customers to collect water
samples. If the Agency could establish
such a correlation, the LCR could be
revised to allow water system operators
to collect samples from outdoor taps;
thereby removing the need for customer-
collected sampling.
  EPA Response: EPA recognizes that
the LCR is a challenging rule that
requires difficult solutions to
implement, but continues to believe that
the public health objective addressed by
the rule is as important and essential
today as it was when the rule was first
promulgated. Since the Agency
promulgated the revisions to  the LCR in
January 2000 (65 FR1950, January 12,
2000 (USEPA, 2000)), the Agency has
received no significant new information
that would support a revision. However,
the Agency recognizes that more
research would be useful to obtain
additional information that could be
utilized to address some of the issues
associated with the implementation of
this rule. For this reason, EPA has
revised its rationale for not revising the
NPDWR for lead and placed it in the
data gaps category. Although the
Agency continues to believe that the
NPDWR for copper belongs in the risk
assessment in process category at the
present time, EPA will also consider
copper-related risk management and
implementation issues as a part of any
LCR-related research plans. The Agency
is committed to working with
stakeholders to support and coordinate
identification and prioritization of LCR-
related research needs. Until  this
research is completed, EPA believes it is
premature to consider revisions to the
LCR; as a result, revision of the LCR is
not appropriate at this time.
  The Agency believes that
understanding the possible correlation
between monitoring results and actual
rates of exposure and public health
protection is a valid issue. However,
EPA recognized during the initial
regulatory development of the LCR that
a significant effort would be necessary
to provide a statistically valid number
and frequency of samples for an
exposure assessment. The Agency thus
adopted an alternative approach which
specified a monitoring scheme that
sought to"* *  * assure that systems are
performing 'optimal corrosion control'
in part by requiring systems to conduct
comprehensive tap sampling at homes
specifically targeted for their potential
to contain elevated levels of lead and
copper" (56 FR 26460 at 26514, June 7,
1991 (USEPA, 1991b}). One issue in
assessing exposure reduction resulting
from the LGR is a determination of an
exposure baseline. EPA does not have a
lot of data against  which to measure
changes in exposure that have occurred
as a result of rule implementation. For
these reasons, EPA believes that there is
still insufficient information to change
the basic monitoring approach adopted
in the original rule, but recognizes that
additional research may be useful.
  Research on whether a correlation
exists between the water quality at
indoor taps and water quality at outdoor
taps is a very complex issue. Several
variables potentially affect whether a
reliable correlation exists between
indoor and outdoor taps. These
variables include: standing time within
the system; contact tune with the
building plumbing; and the content of
the interior plumbing. These variables,
coupled with the fact that lead levels
from building-to-building can be highly
site-specific, make a correlation between
indoor and outdoor taps difficult to
establish. EPA continues to believe that
focusing on the point of delivery to the
customer most closely links the data
collected to the water quality consumed
by the customer.
  EPA recognizes the commenter's
concerns regarding the integrity of
samples collected by drinking water
customers. To date, however, the
Agency has not been able to identify an
acceptable alternative to monitoring at
the consumer's tap that can produce
results equivalent to those obtained at
the point of consumption in terms of
ensuring adequate public health
protection.
  Regarding the commenter's third
recommendation,  EPA will consider this
research need as part of the Agency's
overall drinking water research
planning process.
  b. Relaxing the Monitoring
Requirements. Three commenters
recommended that water systems be
allowed to conduct water quality
parameter [WQP) monitoring in lieu of
continued lead and copper tap
monitoring. One of these commenters
added that this should be allowed once
the system has demonstrated that it does
not have a lead problem. This
commenter also stated that the new
requirements to use lead-free solder and
plumbing fixtures should preclude
problems with lead. Two commenters
noted the difficulty that water systems
are having maintaining their current
sampling pool because homeowners no
longer want to participate hi the LCR
monitoring program. One of these
conunenters recommended using WQP
results to ensure corrosion control
treatment is being adequately
maintained and to stop lead and copper
monitoring after three to five years. The
commenter added that once the system
ceases  lead and copper monitoring, it
can use public education to supplement
continuing corrosion control, and can
use coupons to demonstrate that
corrosion rates meet accepted standards.
  EPA Response: While EPA is sensitive
to the difficulties associated with the
monitoring requirements of the LCR, the
Agency is also concerned about the
implications of reduced or discontinued
monitoring.  Significant treatment
changes or water chemistry disturbances
(such as new water sources, major pH/
coagulation changes, disinfectant
changes, or seasonal water/treatment
changes) can influence the effectiveness
of corrosion control, which in turn will
require appropriate adjustments of
treatment. Current regulations require
water systems to continue monitoring
lead and copper levels to assure that
water quality changes adversely
affecting the presence of these
contaminants in the drinking water are
detected and to assure that appropriate
adjustments to maintain optimal
corrosion control are made. Proper
process control, including water quality
and corrosion inhibitor residual
concentration monitoring in the
distribution system, is the key to making
any corrosion control or other treatment
work, and assure the continuation of
proper water quality. However, EPA
recognizes that some changes might be
justified in the future based on new,
scientifically valid, information and/or
research. EPA is considering aspects
such as the implications of
simultaneous treatment modifications
on water quality, including lead and
copper control, in its research planning.
EPA is not yet able to determine
whether the outcome of such research
will provide a basis for modifications to
the LCR treatment or monitoring

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requirements. As stated in the response
in section IV.B.13.a. of today's action,
EPA has placed the LCR in the data gaps
category pending the completion of
future research.
  c. Corrosion Control Treatment
Strategy. Two commenters noted
concerns regarding the lead and copper
corrosion control strategy. One
commenter indicated that the LCR
should be revised to allow systems to
change corrosion control strategies. The
commenter stated that considerable
development of the corrosion control
market has occurred since systems made
their initial assessments and
implemented corrosion control
programs. The commenter felt that
currently, the "LCR locks utilities into
a given control strategy," when in some
instances limited pilot work and
ongoing WQP monitoring would allow a
system to re-assesses its treatment and
implement an alternative corrosion
control inhibitor.
  The second commenter indicated that
the current corrosion control strategies
are marginally effective at preventing
particulate lead and copper from
entering the water supply. The
commenter recommended that EPA
consider methods for mitigating the
release of insoluble components from
plumbing fixtures.
  EPA Response: The Agency disagrees
that the LCR locks utilities into a given
control strategy, but feels it is necessary
to demonstrate a sound basis for re-
assessing and implementing an
alternative treatment strategy in the
context of the existing regulation. EPA
notes that the current regulation
provides some flexibility to both States
and water systems in the choice of a
corrosion control strategy. For example,
in response to its own initiative, a
request by a water system or other
interested party, a State may modify its
determination of the optimal corrosion
control treatment, among those listed in
the Federal regulation, or may modify
optimal WQPs if the State determines
such changes are necessary to ensure
that the system continues to optimize
corrosion control treatment (40 CFR
141.82(h)).
  The Agency believes that the existing
requirements to notify the State when
changing a corrosion control strategy
remain necessary and appropriate. After
they have optimized corrosion control,
water systems must notify the State of
any treatment changes 7 within 60 days
of the change (40 CFR 141.90(a)(3)). The
  7 Treatment changes are categorized as changes to
 any water quality treatment process, including (but
 not restricted to) diseniection, disinfection by-
 product removal, and corrosion control.
               Agency encourages water systems to
               notify the State prior to making any
               changes thus allowing the Primacy
               Agency to review the changes to reduce
               the potential for detrimental side-
               effects. In the Agency's experience,
               changes in treatment, such as (but not
               restricted to) replacement of high pH
               treatment with corrosion inhibitor,
               changes in coagulant and coagulation
               conditions, changes in disinfection,
               installation of membrane processes, or
               introduction of chemically different
               waters into the distribution system
               provide potential for detrimental side-
               effects. Water treatment changes,
               therefore, should only be done with the
               greatest care and pilot investigations.
               While changes to treatment can be made
               under the existing regulation, systems
               should conduct additional monitoring
               (e.g., of lead, copper, and WQPs) until
               the new treatment is fully implemented
               and stabilized.
                  EPA also recognizes that the current
               LCR may limit flexibility to some extent,
               particularly in the adoption of new or
               emerging technologies. The original rule
               attempted to balance this concern with
               the need to provide strong public health
               protection by ensuring that only control
               strategies of proven effectiveness are
               adopted. The Agency does not have an
               adequate basis to revise the treatment
               requirements at this time but will
               continue to monitor new developments,
               including emerging technology. The
               Agency may consider revisions to the
               LCR prior to the end of the next Six-
               Year Review cycle if the Agency
               receives new,  scientifically-valid,
               information that provides a basis for
               achieving significant improvement in
               public health protection or significant
               cost-savings to utilities and their
               customers while maintaining current
               public health protection.
                  EPA has always recognized that the
               release of insoluble particulate material
               containing lead and copper can be an
               issue in some water systems. While
               more research may be of interest to
               improve optimization of corrosion
               control approaches with respect to this
               source, EPA expects that evaluations
               and pilot studies by water systems
               should include testing and
               consideration of the relative
               effectiveness of different treatments
               towards particulate release in systems
               for which it is important.
                  d. Lead Levels m  School Drinking
                Water. One commenter was concerned
               that the data on lead levels that was
               analyzed under the Six-Year Review of
               NPDWR standards may not indicate
               actual lead contamination of drinking
               water sources. As an example, the
               commenter noted that even though
Baltimore City is in compliance for lead
levels, Vs of Baltimore schools are using
alternative sources of drinking water
due to lead contamination. The
commenter expressed concern that since
data obtained from schools, such as the
data from Baltimore, was not considered
in the evaluation of lead contamination
in Hi-inking water, the most vulnerable
population may not be protected from
exposure to lead. The commenter stated
that it is time for the Agency to reassess
how lead levels are evaluated.
  EPA Response: The LCR is designed
to address system-wide problems with
lead and copper contamination. The
rule does not specifically target
particular structures, such as schools,
but rather contains a monitoring
protocol designed to ensure that the
overall levels of lead and copper
system-wide are minimized. Once
optimal treatment is implemented, any
remaining problems with elevated lead
levels in schools may be due to
plumbing, coolers, or other materials in
the building. These potential sources of
lead in schools are of concern and for
this reason are explicitly addressed
under the provisions of the Lead
Contamination Control Act of 1988
(LCCA) (sections 1461 to 1465 of
SDWAJ. The LCCA directed EPA to
publish a guidance manual and testing
protocol to assist States and schools in
identifying sources and determining the
extent of lead contamination in school
drinking water and, if necessary, in
remedying such contamination.  In
January 1989, the Agency published and
distributed the guidance manual, "Lead
in School's Drinking Water," to States
and schools (USEPA, 1989). hi 1994, the
Agency updated and revised the
guidance manual entitled "Lead in
Drinking Water hi Schools and Non-
residential Buildings" (USEPA,  1994). A
copy of this manual may be obtained
from the Safewater website http://
www.epa.gov/safewater/consumer/
leadinschools.html. In addition, the
LCCA imposed a ban on the
manufacture and sale of water coolers
that are not lead free. The LCCA
requirements are independent of the
NPDWRs and therefore are not
addressed under the Six-Year Review
process. However, the Agency is
continuing to work with schools and
States to address problems dealing with
lead in school drinking water.
14. Lindane (y-hexachlorocyclohexane)
  In the April 17, 2002, Federal
Register, the Agency preliminarily
placed lindane in the no revision
category because a health risk
assessment was pending at the time of
publication. One commenter stated that

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                                                                    42925
the RED risk assessment for lindane,
issued after publication of the April 17,
2002, Federal Register, should be
considered in the Agency's review of
the NPDWR and expressed concerns
regarding the existing regulation. The
commenter stated that the current
NPDWR is based on an RfD developed
in 1988 on the basis of adverse kidney
effects and should be revised (USEPA,
1988). The kidney effects were
determined to occur through a pathway
that is not relevant to human health risk
assessment. The commenter stated that
the new OPP toxicological assessment
has resulted in a significant change to
the quantitative dose-response
assessment for lindane and that there
are no data gaps or uncertainties which
would prevent a revision of the NPDWR
for lindane at this time.
  EPA Response: Since the publication
of the April 17, 2002, Federal Register
and receipt of the comment regarding
lindane, the Agency has finalized the
risk assessment for lindane and signed
the RED on July 31, 2002. The
remaining paragraphs in this section
include a brief background discussion
about the original promulgation of the
lindane NPDWR, the results of the
appropriate six-year technical reviews
and the Agency's revise/not revise
decision.
  a. Background. EPA published the
current NPDWR for lindane on January
30,1991 [56 FR 3526 (USEPA, 1991a)).
The NPDWR established an MCLG and
an MCL of 0.0002 mg/L. The Agency
based the MCLG on an RfD of 0.0003
mg/kg/day and a cancer classification of
C, possible human carcinogen.
  b. Technical Reviews. EPA updated
the risk assessment on July 31, 2002
(USEPA, 2002h). The new risk
assessment established an RfD of 0.0047
mg/kg/day. The Food Quality Protection
Act (FQPA) of 1996 provides for an
additional safety factor of up to 10-fold,
if necessary, in assessing the risks to
infants and children to take into account
the potential for pre- and post-natal
toxicity, and the completeness of the
toxicity and exposure databases. This is
referred to as the FQPA safety factor.
The Agency concluded that an FQPA
safety factor of three was required for
lindane since there is evidence for
increased susceptibility of the young
demonstrated in a developmental
neurotoxiciry and two-generation
reproductive toxicity study in rats. The
rationale for using an FQPA safety factor
of three is detailed in the RED.
  In accordance with the 1999 EPA
Draft "Guidelines for Carcinogen Risk
Assessment" (USEPA, 1999a), the
Agency classified lindane as "suggestive
evidence of carcinogenicity, but not
sufficient to assess human carcinogenic
potential." Based on the RfD for lindane
of 0.0047 mg/kg/day, the application of
the additional FQPA safety factor of
three to this RfD, a 20 percent RSC, and
a 10-fold risk management factor of
suggested evidence of carcinogenicity,
EPA used 0.001 mg/L as a level for
evaluating the occurrence data.
  Analytical or treatment feasibility do
not pose any limitations for the current
MCL and would not be a limiting factor
at the 0.001 mg/L level (USEPA, 2003a;
USEPA 2003g). The Agency's review of
possible "other regulatory revisions"
did not identify any issues that are
specific to lindane {USEPA, 2003b).
  EPA evaluated the results of the
occurrence and exposure analyses for
lindane to determine whether possible
changes to the standard would be likely
to result in a meaningful opportunity for
cost-savings to public water systems and
their customers (USEPA,  2003d). Table
IV-2 shows the results of the detailed
occurrence and exposure analysis based
on the 16-State cross-section for
concentrations of 0.0002 mg/L (the
current MCL), and for 0.001 mg/L.
Based on the  detailed analysis,  it
appears that lindane is unlikely to occur
at concentrations above 0.0002  mg/L in
the States used for the cross-section.
BILLING CODE 6560-50-P

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Table IV-2: Lindane Occurrence1
Systems1
Level
(in mg/L)
Level Evaluated 0.001
Current MCL 0.0002
16-State Cross-
Section - Total
Systems with Data
16,098
1 6,098
Estimated ft of Systems
> Level Evaluated
(credible intervals)*1*
0 (0-0)
0 (0-0)
Estimated % of Systems
> Level Evaluated
(credible intervals)3
0.000% (0.000% - 0.000%)
0.000% (0.000% - 0.000%)
Population Served by Systems1
Level
(in mg/L)
Level Evaluated 0.001
Current MCL 0.0002
16-State Cross-
Section - Total
Population Served
by Systems with
Data
99,942,600
99,942,600
Estimated Population
Served by Systems
> Level Evaluated
(credible intervals)3
0 (0-0)
0 (0-0)
Estimated % of Population
Served by Systems
> Level Evaluated
(credible intervals)3
0.000% (0.000% - 0.000%)
0.000% (0-000% - 0.000%)
Notes:
1 Results are based on the number and percent of systems (and the corresponding population served by those systems) with estimated
mean concentrations above the specified level of evaluation.
2 All percentages are shown to three significant figures. All system values are rounded to the nearest whole system. All population
values are rounded to the nearest hundred.
3 "Credible intervals" are generated to quantify the uncertainty around each estimated probability in the Bayesian analysis of the
occurrence data. For further explanation of credible intervals and the Bayesian analysis, please see "Occurrence Estimation
Methodology and Occurrence Findings Report for the Six-Year Review of Existing National Primary Drinking Water Regulations"
(USEPA, 2003d).
4 This value does not necessarily reflect the number of systems out of compliance with the current MCL, because these data were
collected over the 1993-1997 time period, and because the value represents the estimated mean value over that time period, not the
running quarterfv average on which compliance is based.

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                                                                   42927
  The results of the detailed occurrence
and exposure analysis indicate that few,
if any, of the 16,098 systems sampled in
the 16-State cross-section might be
affected if EPA were to consider levels
as high as 0.001 mg/L. The current
BATs and small system compliance
technology for lindane have other
beneficial effects (e.g., reduction of
other co-occurring contaminants, or
other common impurities) in addition to
lindane removal. Therefore, if EPA were
to consider a higher level, the Agency
does not know how many of these
public water systems that are currently
treating to comply with the current MCL
of 0.0002 mg/L would be likely to
discontinue any treatment that is
already in place (USEPA, 2002c;
USEPA, 2003g).
  c. Current Decision. Although there
are new health effects data that might
support calculation of a less stringent
standard for lindane, EPA does not
believe a revision to the NPDWR for
lindane is appropriate at this time. In
making this decision, the Agency
considered whether any potential
revision to the lindane NPDWR is likely
to provide a meaningful opportunity for
cost-savings to public water systems and
their customers. After consideration of
this factor, EPA has decided that any
revision to lindane would be a low
priority activity for the Agency, and,
thus, is not appropriate to revise  at this
time because of:
  • Competing workload priorities;
  • The administrative costs associated
with rulemaking; and
  • The burden on States and the
regulated community to implement any
regulatory change that resulted.

15. Simazine
  One commenter agreed that simazine
should be addressed after the risk
assessment is completed in 2003  or
2004. The commenter requested that the
Office of Water (OW) work  closely widi
the OPP on the risk assessment at that
time. The commenter also
recommended that OW address the
revision of the existing simazine
NPDWR before the next review cycle
year, scheduled for 2008. The
commenter believes the extensive
mammalian toxicology database,
submitted as part of the Triazine  Special
Review, can be used in this process.
  EPA Response: OW has been
coordinating with OPP for the revision
of the atrazine and simazine risk
assessments. Once the simazine risk
assessment is completed, EPA will
determine whether a compelling  reason
exists to consider review of the simazine
NPDWR on an accelerated schedule.
C. What Comments Did EPA Receive
Regarding the Review of
Implementation-Related Issues for
Chemical NPDWRs?
  Several commenters recommended
that EPA ensure consistent application
of rules by making rules more consistent
with respect to monitoring frequency,
triggers for increased monitoring,
criteria for returning to routine
monitoring, and criteria for reducing
sample requirements. In addition,
commenters suggested that the Agency
review possible ways for reducing the
reporting burden on States, which could
free up State resources currently used to
implement rules.
  One commenter was concerned about
monitoring and reporting issues in
conjunction with CMR. The commenter
felt that EPA should not miss an
opportunity to relieve some of the
unnecessary confusion that the
monitoring requirements of Phase n and
V have created. This confusion includes
issues such as, what a detection is and
what the monitoring requirements are
for systems in States without a waiver
program. EPA was encouraged to
provide this consistency as much as
possible, including using the standard
monitoring framework to allow States
and water systems to more easily
understand rule requirements and
reduce the need for States to update
their data management systems.
  One commenter said EPA should
ensure consistent application of rules by
determining whether or not chronic
contaminants should be regulated at
non-transient non-community water
systems (NTNCWSs), and review
existing NPDWRs to ensure that rules
are applied consistently. Another
commenter recommended that the
compliance language for the synthetic
organic chemicals (SOCs) and volatile
organic chemicals (VOCs) in the Final
Arsenic Rule  (66 FR 6975, January 22,
2001 (USEPA, 2001)) be adopted for the
inorganic chemicals (lOCs), and that
systems not be considered hi violation
of the MCL until it has completed one
year of quarterly samples.
  EPA Response: The Agency agrees
that consistency across regulations is
desirable to the extent that it does not
jeopardize public health protection or
the environment.
  As part of the Advanced Notice of
Proposed Rulemaking for CMR (62 FR
36100, July 3,1997 (USEPA, 1997a)),
EPA considered some of the issues
raised by the commenters. However,
during the comment period for the
CMR, stakeholders generally indicated
that the existing monitoring framework
was sufficient. Most State commenters
indicated that it would be too
burdensome to adopt CMR. As a result,
the Agency decided to take no further
action on the CMR. However, the
Agency established a standardized
monitoring framework which applies to
all of the regulated chemical and
radiological contaminants (except lead
and copper). The new chemical and
radiological rules that EPA has
promulgated (e.g., arsenic and
radionuclides) are coordinated with the
standardized monitoring framework.
The Agency made special efforts to
ensure that the reduced monitoring
periods are in line with the 3-year
compliance periods in the standardized
monitoring framework.
  To assist States with understanding
rule requirements, the Agency
conducted a series of Phase D7V training
in 2001. The training provided
information to help States make
informed decisions about reducing
quarterly monitoring requirements.
With respect to reduced monitoring,
States currently have the flexibility to
reduce the frequency of monitoring and/
or to waive sampling requirements for
any given contaminant after minimum
criteria are met to demonstrate that the
system is reliably and consistently
below the MCL and/or not vulnerable to
contamination.
  NTNCWSs are traditionally regulated
for chronic contaminants. However,
through an alternative mechanism, the
Agency is currently evaluating risk and
exposure as they pertain to NTNCWS
monitoring requirements. This review
will not be completed in time for this
Six-Year Review process. Until all the
issues have been identified and specific
options have been formulated, it will
not be clear if a revision to regulations
is indicated.
  EPA intends to consistently
implement compliance determination
provisions for lOCs, SOCs, and VOCs for
all NTNCWSs and community water
systems, as described in the preamble to
the Final Arsenic Rule (66  FR 6975 at
6990, January 22, 2001 (USEPA, 2001)).
The rule makes compliance
determinations based on a running
annual average. The clarifications to
compliance determinations for SOCs,
lOCs, and VOCs are based  on the
average of the initial MCL exceedance
and any subsequent State-required
confirmation samples. States have the
flexibility to require confirmation
samples and more frequent monitoring,
in addition to required quarterly
samples. The average of the exceedance
and confirmation sample constitutes the
first quarterly sample. Compliance with
the MCL is based on the average of the
first quarterly sample and three

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additional samples over a period of one
year, unless any one quarterly sample
would cause the running annual average
to exceed the MCL. Then the system is
out of compliance immediately.
D. What Comments Did EPA Receive on
the Total Coliform Rule?
  Several commenters addressed the
TCR. Several commenters raised several
issues relating to monitoring.  Some
contended that routine monitoring
should be focused on critical locations
in the distribution system, rather than
on the current requirement to monitor
all parts of the distribution system. They
also urged EPA to allow the use of
dedicated sampling taps. Some
commenters argued for allowing a
finished water storage reservoir as a
routine monitoring site. Two
commenters urged EPA to focus on E.
coli as the measure of water quality in
the distribution system, rather than on
total colifbrms. hi addition to routine
monitoring, a few commenters
addressed the topic of repeat samples
after a total coliform-positive  sample.
One commenter, for example, urged
EPA to eliminate the requirement to
take upstream and downstream repeat
samples after a total coliform-positive
sample. Environmental groups urged
EPA to strengthen the TCR and other
rules that protect against pathogens, and
exhorted EPA not to ease the TCR
burden such that public health is
compromised.
  EPA Response: EPA's announcement
in the April 17, 2002, Federal Register
was only intended to discuss  the
Agency's intent to begin the process for
revising the TCR. EPA will consider the
commenters' suggestions as part of the
revision process.  As stated in the April
17, 2002, Federal Register, the Agency
plans to consider revisions to the TCR
with new requirements for ensuring the
integrity of distribution systems. The
Agency remains committed to obtaining
input from stakeholders as part of the
rule development process. EPA agrees
with the comment that public health
should not be compromised, and will
consider only those revisions that will
assure public health protection.
E. What Comments Did EPA Receive on
Research Needs?
  Commenters found that EPA's
information on potential research
resulting from the review of NPDWRs
would be better represented by a
summary of research needs that were
identified by the Agency. Commenters
felt that this summary is important to
inform future regulatory decisions.
Commenters also suggested additional
research needs that had not been
                identified by EPA in its preliminary
                review.
                  EPA Response: EPA agrees that the
                identification of research needs is an
                important component of the review of
                NPDWRs. Research findings may
                support future reviews and/or revisions
                to NPDWRs.
                  The Agency is considering research
                needs that it identified as part of the
                review as well as those suggested by
                commenters. EPA will continue to
                identify areas where data are lacking.
                Dialogue with industry and other
                groups, including those that sponsor or
                conduct research on priority areas,
                would be beneficial to the drinking
                water program. Collaboration in
                sponsoring studies can provide multiple
                benefits.
                  There are two research needs
                associated wife the Six-Year Review
                that are being addressed through
                mechanisms external to EPA. The
                National Research Council of the
                National Academy of Sciences is
                conducting an assessment of recent data
                on fluoride health effects. In addition,
                the National Toxicology Program is
                conducting a study on chromium VI
                toxicity. Both of these research efforts
                are discussed in the April 17, 2002,
                Federal Register announcement of
                EPA's preliminary revise/not revise
                decisions. The current review identified
                several general and specific areas of
                potential research related to treatment.
                The treatment-related research areas are
                briefly discussed in the Treatment
                Feasibility Document (USEPA, 2003g).
                  EPA is currently in the process of
                examining whether specific research
                needs exist within each of the  Six-Year
                Review areas of regulatory consideration
                (i.e., health effects, analytical methods,
                treatment, implementation, and
                occurrence/exposure). Some of the
                research needs identified during the
                Six-Year Review effort will be  discussed
                in the context of the Multi-Year Plan
                (MYP) for drinking water. The MYP
                describes the EPA Office of Research
                and Development's fiscal year  2003 to
                2010 research program to support the
                regulatory  development activities of the
                EPA Office of Water. EPA plans to make
                this document available to the public in
                2003.

                V. References

                National Drinking Water Advisory Council
                    (NDWAC). 2000. Recommended
                    Guidance for Review of Existing National
                    Primary Drinking Water Regulations.
                    November 2000. Available on the
                    Internet at:
                    http://www.epa.gov/safewater/ndwac/
                    gaidfnl.pdf.
                National Research Council (NRC). 1993.
    Health Effects of Ingested Fluoride.
    National Academy Press, Washington,
    DC. August 1993. Available on the
    Internet at: http-Jfbooks.nap.Bdu/books/
    03090497SX/html/Rl.html.
National Toxicology Program (NTP). 2002.
    NTP study of the hexavalent chromium
    compound sodium dichromate
    dihydrate. Available on the Internet at:
    http://ntp-server.niehs.nih.gov/htdocs/
    Studies/HexChromium/
    hexchromiumpgJttml.
Schroeder, H.A., Mitchener, M. and Nason,
    A.P. 1970. Zirconium, niobium,
    antimony, vanadium and lead in rats: life
    term studies. Journal of Nutrition. 100:
    59-68.
Senate Report. 1995. Committee of
    Environment and Public Works, Safe
    Drinking Water Act Amendments of
    1995, S. Doc. No. 169,104th Cong., 1st
    Sess. 38 (1995).
USEPA. 1986. EPA  Guidelines for Carcinogen
    Risk Assessment Federal Register. Vol.
    51, No. 185. p.  33992, September 24,
    1986.
USEPA. 1987. National Primary Drinking
    Water Regulations—Synthetic Organic
    Chemicals; Monitoring for Unregulated
    Contaminants;  Final Rule. Federal
    Register. Vol. 52, No. 330. p. 25690, July
    8,1987.
USEPA. 1988. Integrated Risk Information
    System, gamma-Hexachlorocyciohexane.
    Available on the Internet at: http://
    www. epa .gov/iris/subst/0065Jitm.
USEPA. 1989. Lead in School Drinking
    Water. EPA 570/9-89-001. January 1989.
USEPA. 1991a- National Primary Drinking
    Water Regulations—Synthetic Organic
    Chemicals and Inorganic Chemicals;
    Monitoring for Unregulated
    Contaminants;  National Primary
    Drinking Water Regulations
    Implementation; National Secondary
    Drinking Water Regulations; Final Rule.
    Federal Register. Vol. 56, No. 30. p.
    3526, January 30,1991.
USEPA.  199lb. Maximum Contaminant Level
    Goals and National Primary Drinking
    Water Regulations for Lead and Copper;
    Final Rule. Federal Register. Vol. 56, No.
    110. p. 26460, June 7,1991.
USEPA.  1992. Final Regulatory Impact
    Analysis National Primary Drinking
    Water Regulations: Phase V Synthetic
    Organic and Inorganic Chemicals.
    February 1992.
USEPA.  1993. Reregjstration Eligibility
    Decision (RED)—Glyphosate. EPA Report
    738-JI-93-014. Washington, DC: Office
    of Prevention, Pesticides, and Toxic
    Substances. September 1993. Available
    on the Internet at: http://www.epa.gov/
    oppsrnn/REDs/old^reds/glyphosate.pdf.
USEPA. 1994. Lead in Drinking Water in
    Schools and Non-Residential Buildings.
    EPA 812-B-94-002. Office of Water.
    April 1994.
USEPA. 1997a. National Primary Drinking
    Water Regulations—Advance Notice of
    Proposed Rulemaking. Federal Register.
    Vol. 62, No. 156. p. 36100, July 3,1997.
USEPA. 1997b. Alternative Monitoring
    Guidelines. EPA 816-R-97-011. August
    1997. Available on the Internet at http:/

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                         Federal Register/Vol.  68, No.  138/Friday,  July 18, 2003/Notices
                                                                         42929
    /www.epa.gov/safewater/regs/
    pmrfin-html.
USEPA. 1998. IRIS, Beryllium and
    Compounds. Available on the Internet at:
    http://www.epa.gov/iris/subst/0012.htm.
USEPA. 1999a. Guidelines for Carcinogen
    Risk Assessment. NCEA-F-0644 Review
    Draft. Environmental Protection Agency
    Risk Assessment Forum. Washington,
    DC. July 1999.
USEPA. 1999b. Revisions to the Unregulated
    Contaminant Monitoring Regulations for
    Public Water Systems; Final Rule.
    Federal Register. Vol. 64, No. 180. p.
    50556, September 17,1999.
USEPA. 1999c. A Review of Contaminant
    Occurrence in Public Water Systems.
    EPA 81&-R-99-006. 78 pp. November
    1999.
USEPA. 2000. National Primary Drinking
    Water Regulations for Lead and Copper;
    Final Rule. Federal Register. Vol. 65, No.
    8. p. 1950, January 12, 2000.
USEPA. 2001. National Primary Drinking
    Water Regulation: Arsenic and
    Clarifications to Compliance and New
    Source Contaminants Monitoring; Final
    Rule. Federal Register. Vol. 66. No. 14.
    p. 6975, January 22, 2001.
USEPA. 2002a. Integrated Risk Information
    System (IRIS); Announcement of 2002
    Program; Request for Information;
    Notice. Federal Register. Vol. 67, No. 6.
    p. 1212, January 9, 2002.
USEPA. 2002b. Water Treatment Technology
    Feasibility Support Document for
    Chemical Contaminants; In support of
    EPA Six-Year Review of National
    Primary Drinking Water Regulations.
    EPA 815-D-02-001. Draft. February
    2002.
USEPA. 2002c. An Evaluation of Available
    Economic Information in Support of the
    Six-Year Review of Existing National
    Primary Drinking Water Regulations.
    Memo from Marc Parrotta, Targeting and
    Analysis Branch, Office of Ground Water
    and Drinking Water. March 2002.
USEPA. 2002d. EPA Protocol for Review of
    Existing National Primary Drinking
    Water Regulations. EPA 815-D-02-O04.
    Draft. March 2002.
USEPA. 2002e. Occurrence Estimation
    Methodology and Occurrence Findings
    Report for the Six-Year Review of
    Existing National Primary Drinking
    Water Regulations. EPA 815-D-02-005.
    Draft. March 2002.
USEPA. 2002f. Occurrence Summary and
    Use Support Document for the Six-Year
    Review of Existing National Primary
    Drinking Water Regulations. EPA 815-
    D-02-006. Draft. March 2002.
USEPA. 2002g. National Primary Drinking
    Water Regulations—Announcement of
    the Results of EPA's Review of Existing
    Drinking Water Standards and Request
    for Public Comment; Proposed Rule.
    Federal Register. Vol. 67, No. 74. p.
    19030, April 17, 2002.
USEPA. 2002h. Reregistration Eligibility
    Decision (RED)—Lindane. EPA 73&-R-
    02-012. Office of Prevention, Pesticides,
    and Toxic Substances. July 2002.
    Available on the Internet at: http://
    www.epa.gov/oppsrrdl/REDs/
    lindane_red.pdf.
USEPA. 2002i. Integrated Risk Information
    System (IRIS), 1,1-Dichloroethylene.
    August 2002. Available on the Internet
    at:
    http://www.epa.gov/iris/subst/0039.htm.
USEPA. 2O03a. Analytical Feasibility
    Support Document for the Six-Year
    Review of Existing National Primary
    Drinking Water Regulations
    (Reassessment of Feasibility for
    Chemical Contaminants). EPA 815-R-
    03-003. Final. March 2003.
USEPA. 2003b. Consideration of Other
    Regulatory Revisions for Chemical
    Contaminants in Support of the Six-Year
    Review of National Primary Drinking
    Water Regulations. EPA 815-R-03-005.
    Final. June 2003.
USEPA. 2003c. EPA Protocol for Review of
    Existing National Primary Drinking
    Water Regulations. EPA 815-R-03-O02.
    Final. June 2003.
USEPA. 2003d. Occurrence Estimation
    Methodology and Occurrence Findings
    Report for the Six-Year Review of
    Existing National Primary Drinking
    Water Regulations. EPA 815-R-03-006.
    Final. June 2003.
USEPA. 2003e. Public Comment and
    Response Summary for the Six-Year
    Review of National Primary Drinking
    Water Regulations. EPA 815-R-03-001.
    Final. June 2003.
USEPA. 2003f. Six-Year Review—Chemical
    Contaminants—Health Effects Technical
    Support Document. EPA 822-R-03-008.
    Final. June 2003.
USEPA. 2003g. Water Treatment Technology
    Feasibility Support Document for
    Chemical Contaminants; In Support of
    EPA Six-Year Review of National
    Primary Drinking Water Regulations.
    EPA 815-R-03-004. Final. June 2003.
USEPA. 2003h. Integrated Risk Information
    System (IRIS); Announcement of 2003
    Program; Request for Information and
    Announcement of Workshop; Notice.
    Federal Register. Vol. 68, No. 24. p.
    5870, February 5, 2003.

  Dated:  July 11, 2003.
Linda J. Fisher,
Acting Administrator.
 [FRDoc. 03-18152 Filed 7-17-03; 8:45 am]
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                  United States
                  Environmental Protection
                  Agency
Office of Enforcement and Compliance Assuranci
                          EPA300-F-03-001
(2201 A)
lay 2003
            U. S.  EPA Small  Business  Resources
   If you own a small business, the United States Environmental Protection Agency (EPA) offers
   a variety of compliance assistance and toots to assist you in complying with federal and state
environmental laws. These resources can help you understand your environmental obligations, improve
compliance and find cost-effective ways to comply through the use of pollution prevention and other
innovative technologies.
Hotlines, Helplines and
Clearinghouses
EPA sponsors approximately 89 free hotlines and clearing-
houses that provide convenient assistance regarding
environmental requirements.

The National Environmental Compliance Assistance
Clearinghouse provides quick access to compliance
assistance tools, contacts, and planned activities from the
U.S. EPA, states, and other compliance assistance
providers: http://www.epa.gov/ciearinghouse

Pollution Prevention Clearinghouse
http://www.epa.gov/opptintr/library/ppicindex.htm

EPA's Small Business Ombudsman Hotline can
provide a list of all the hot lines and assist in deter-
mining the hotline best meeting your needs:
(800) 368-5888

Emergency Planning and Community Right-To-Know Act
(800) 424-9346

National Response Center (to report oil and hazardous
substance spills)
(800)424-8802

Toxics Substances and Asbestos Information
(202)554-1404

Safe Drinking Water
(800)42^4791

Stratospheric Ozone and Refrigerants Information
(800)296-1996

Clean Air Technology Center
(919)541-0800

Wetlands Helpline
(800)832-7828
   EPA Websites
   EPA has several Internet sites that provide useful compli-
   ance assistance information and materials for small
   businesses. If you don't have access to the Internet at
   your business, many public libraries provide access to the
   Internet at minimal or no cost.

   EPA's Home Page
   http://www.epa.gov

   Small Business Assistance Program
   http ://www. epa.gov/ttn/sbap

   Office of Enforcement and Compliance Assurance
   http://www.epa.gov/compliance

   Compliance Assistance Home Page
   http://www.epa.gov/compliance/assistance

   Office of Regulatory Enforcement
   http://www.epa.gov/compliance/civif/index.html

   Office of Site Remediation Enforcement
   http://www.epa.gov/compliance/cleanup

   Innovative Programs for Environmental Performance
   http://www.epa.gov/partners

   Small Business Ombudsman
   www.sba.gov/ombudsman
             Office of Enforcement and Compliance Assurance: http://www.epa.gov/compliance
 Recycled/Recyclable
 Printed with Soy/Canola Ink on paper that contains at least 30% post consumer fiber

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                     U.S.  EPA SMALL  BUSINESS RESOURCES
Compliance Assistance Centers
In partnership with industry, universities, and other federal
and state agencies, EPA has established national Compli-
ance Assistance Centers that provide Internet and "faxback"
assistance services for several industries with many small
businesses. The following Compliance Assistance Centers
can be accessed through the Center's gateway at http://
www.assistancecenters.net or by calling the phone numbers
below and at their respective websites:

Metal Finishing
(1 -800-AT-NMFRC or www.nmfrc.org)

Printing
(1 -888-USPNEAC or www.pneac.org)

Automotive Service and Repair
(1-888-GRN-LINKor www.ccar-greenlink.org)

Agriculture
(1-888-663-2155orwww.epa.gov/agriculture)

Printed Wiring Board Manufacturing
(1-734-995-4911 orwww.pwbrc.org)

The Chemical Industry
(1 -800-672-6048 or www.chemalliance.org)

The Transportation Industry
(1-888-459-0656orwww.transource.org)

The Paints and Coatings Center
(1 -800-286-6372 orwww.paintcenter.org)

Three new centers are under development for the auto
salvage sector, the construction industry, and U.S. Mexi-
can border waste issues.
State Agencies
Many state agencies have established compliance assis-
tance programs that provide on-site and other types of
assistance. Contact your local state environmental agency
for more information. For assistance in reaching state
agencies, call EPA's Small Business Ombudsman at
(800)-368-5888 or visit the Small Business Environmental
Homepage at http://www.smallbiz-enviroweb.org/state.html.

Compliance Incentives
EPA provides incentives for environmental compliance. By
participating  in compliance assistance programs or
voluntarily disclosing and promptly correcting violations,
businesses may be eligible for penalty waivers or reduc-
tions. EPA has two policies that potentially apply to small
businesses: The Audit Policy (http://www.epa.gov/compli-
ance/incentives/auditing) and the Small Business Policy
(http://www.epa.gov/compliance/incentives/smallbusiness).
These do not apply if an enforcement action has already
been initiated.

Commenting on Federal  Enforcement
Actions and Compliance Activities
The Small Business Regulatory Enforcement Fairness Act
(SBREFA) established an ombudsman ("SBREFAOmbuds-
man") and 10 Regional Fairness Boards to receive comments
from small businesses about federal agency enforcement
actions. The SBREFA Ombudsman will annually rate each
agency's responsiveness to small businesses. If you believe
that you fall within the Small Business Administration's
definition of a small business (based on your North American
Industry Classification System (NAICS) designation, number
of employees or annual receipts, defined at 13 C.F.R.
121.201; in most cases, this means a business with 500 or
fewer employees), and wish to comment on federal enforce-
ment and compliance activities, call the SBREFA
Ombudsman's toll-free number at 1-888-REG-FAIR (1-888-
734-3247).

Every small business that is the subject of an enforcement
or compliance action is entitled to comment on the
Agency's actions without fear of retaliation.  EPA
employees are prohibited from using enforcement or any
other means of retaliation against any member of the
regulated community because the regulated community
previously commented on its activities.
Your Duty to Comply
If you receive compliance assistance or submit comments
to the SBREFA Ombudsman or Regional Fairness Boards,
you still have the duty to comply with the law, including
providing timely responses to EPA information requests,
administrative or civil complaints, other enforcement
actions or communications. The assistance information
and comment processes do not give you any new rights or
defenses in any enforcement action. These processes
also do not affect EPA's obligation to protect public health
or the environment under any of the environmental statutes
it enforces, including the right to take emergency remedial
or emergency response actions when appropriate. Those
decisions will be based on the facts in each situation. The
SBREFA Ombudsman and Fairness Boards do not
participate in resolving EPA's enforcement actions. Also,
remember that to preserve your rights, you need to comply
with all rules governing the enforcement process.
    EPA is  disseminating  this information to you
    without making a determination that your business
    or organization is a small business as defined by
    Section 222 of the Small Business Regulatory
    Enforcement Fairness Act (SBREFA) or related
    provisions.

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