National Primary Drinking Water Regulations; Radionuclides; Final Rule

[Federal Register: December 7, 2000 (Volume 65, Number 236)]
[Rules and Regulations]
[Page 76707-76753]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07de00-10]
[[Page 76708]]

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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 9, 141, and 142
[FRL-6909-3]
RIN 2040-AC98

AGENCY: Environmental Protection Agency.
ACTION: Final rule.

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SUMMARY: Today, EPA is finalizing maximum contaminant level goals
(MCLGs), maximum contaminant levels (MCLs), and monitoring, reporting,
and public notification requirements for radionuclides. Today's rule is
only applicable to community water systems. Today's rule includes
requirements for uranium, which is not currently regulated, and
revisions to the monitoring requirements for combined radium-226 and
radium-228, gross alpha particle radioactivity, and beta particle and
photon radioactivity. Based on an improved understanding of the risks
associated with radionuclides in drinking water, the current MCL for
combined radium-226/-228 and the current MCL for gross alpha particle
radioactivity will be retained. Based on the need for further
evaluation of the various risk management issues associated with the
MCL for beta particle and photon radioactivity and the flexibility to
review and modify standards under the Safe Drinking Water Act (SDWA),
the current MCL for beta particle and photon radioactivity will be
retained in this final rule, but will be further reviewed in the near
future.
Some parts of EPA's 1991 proposal, including the addition of MCLGs
and the National Primary Drinking Water Regulation (NPDWR) for uranium,
are required under the SDWA. Other portions were intended to make the
radionuclides NPDWRs more consistent with other NPDWRs, e.g., revisions
to monitoring frequencies and the point of compliance. Lastly, some
portions were contingent upon 1991 risk analyses, e.g., MCL revisions
to the 1976 MCLs for combined radium-226 and -228, gross alpha particle
radioactivity, and beta particle and photon radioactivity. The portions
required under SDWA and the portions intended to make the radionuclides
NPDWRs more consistent with other NPDWRs are being finalized today. The
portions contingent upon the outdated risk analyses supporting the 1991
proposal are not being finalized today, in part based on updated risk
analyses.

DATES: This regulation is effective December 8, 2003. The incorporation
by reference of the publications listed in today's rule is approved by
the Director of the Federal Register as of December 8, 2003. For
judicial review purposes, this final rule is promulgated as of 1 p.m.
Eastern Time on December 7, 2000.

ADDRESSES: The record for this regulation has been established under
the docket name: National Primary Drinking Water Regulations for
Radionuclides (W-00-12). The record includes public comments,
applicable Federal Register notices, other major supporting documents,
and a copy of the index to the public docket. The record is available
for inspection from 9 a.m. to 4 p.m., Eastern Standard Time, Monday
through Friday, excluding Federal holidays, at the Water Docket, 401 M
Street SW, East Tower Basement (Room EB 57), Washington, DC 20460. For
access to the Docket materials, please call (202) 260-3027 to schedule
an appointment.

FOR FURTHER INFORMATION CONTACT: For technical inquiries, contact David
Huber, Standards and Risk Management Division, Office of Ground Water
and Drinking Water, EPA (MC-4607), 1200 Pennsylvania Avenue, NW.,
Washington, DC 20460; telephone (202) 260-9566. For general inquiries,
the Safe Drinking Water Hotline is open Monday through Friday,
excluding Federal holidays, from 9:00 a.m. to 5:30 p.m. Eastern
Standard Time. The Safe Drinking Water Hotline toll free number is
(800) 426-4791.

SUPPLEMENTARY INFORMATION:

Regulated Entities

Entities potentially regulated by this rule are public water
systems that are classified as community water systems (CWSs).
Community water systems provide water for human consumption through
pipes or other constructed conveyances to at least 15 service
connections or serve an average of at least 25 people year-round.
Regulated categories and entities include:

------------------------------------------------------------------------
Examples of regulated
Category entities
------------------------------------------------------------------------
Industry.................................. Privately-owned community
water systems.
State, Tribal, Local, and Federal Publicly-owned community
Governments. water systems.
------------------------------------------------------------------------

This table is not intended to be exhaustive, but rather, provides a
guide for readers regarding entities likely to be regulated by this
action. Other types of entities not listed in the table could also be
regulated. To determine whether your facility is regulated by this
action, you should carefully examine the applicability criteria in
Secs. 141.26(a)(1)(i), 141.26(a)(1)(ii), 141.26(b)(1), and 141.26(b)(2)
of this rule. If you have questions regarding the applicability of this
action to a particular entity, consult the person listed in the
preceding FOR FURTHER INFORMATION CONTACT section.

Abbreviations and Acronyms Used in This Document

ASTM: American Society for Testing and Materials
AWWA: American Water Works Association
BAT: Best available treatment
BEIR: Biological effects of ionizing radiation
CFR: Code of Federal Regulations
CWS: Community water systems
EDE: Effective dose equivalent
EML: Environmental Measurements Laboratory
FR: Federal Register
ICRP: International Commission on Radiological Protection
IE: Ion exchange
kg: Kilogram
L/day: Liter per day
LET: Low energy transfer
LOAEL: Lowest observed adverse effect level
MCL: Maximum contaminant level
MCLG: Maximum contaminant level goal
mg/L: Milligram per liter
µg/L: Microgram per liter
mGy: MilliGray
mrem: Millirem
mrem/yr: Millirem per year
NBS: National Bureau of Standards
NDWAC: National Drinking Water Advisory Committee
NIRS: National Inorganic and Radionuclide Survey
NIST: National Institute of Standards and Technology
NODA: Notice of Data Availability
NPDWRs: National Primary Drinking Water Regulations
NRC: National Research Council
NTIS: National Technical Information Service
NTNC: Non-transient, non-community
NTNCWS: Non-transient, non-community water systems
pCi: Picocurie
pCi/L: Picocurie per liter
PE: Performance evaluation
PNR: Public Notification Rule
POE: Point-of-entry
POU: Point-of-use
PQL: Practical quantitation level
PT: Performance testing
RADRISK: A computer code for radiation risk estimation
RfD: Reference dose
RO: Reverse osmosis
SM: Standard methods
SMF: Standardized monitoring framework
SSCTL: ``Small Systems Compliance Technology List''
SWTR: Surface Water Treatment Rule
TAW: Technical Advisory Workgroup
UCMR: Unregulated Contaminant Monitoring Rule

[[Page 76709]]

UNSCEAR: United Nations Scientific Committee on the Effects of
Atomic Radiation
USDOE: United States Department of Energy
USEPA: United States Environmental Protection Agency
USGS: United States Geological Survey

Table of Contents

I. Background and Summary of the Final Rule
A. What did EPA propose in 1991?
B. Why did EPA propose changes to the radionuclides drinking
water regulations in 1991?
C. What new information has become available since 1991?
Overview of the 2000 Notice of Data Availability (NODA).
D. What are the rationales for the regulatory decisions being
promulgated today?
1. Retaining the Combined Radium-226 and Radium-228 MCL
a. Major Comments Regarding Retention of the Combined Radium-226
and Radium-228 MCL
2. The Final Uranium MCL
a. What is the final MCL for uranium and the rationale for that
regulatory level?
b. MCLG and Feasible Level for Uranium
c. Basis for 1991 Proposed MCL and Cancer Risk from Uranium
d. Uranium Health Effects: Kidney Toxicity
e. New Kidney Toxicity Analyses Announced in the NODA
f. Costs and Benefits from Regulating Uranium in Drinking Water
g. Administrator's Decision to Promulgate MCL Higher than Feasible Level
h. California Drinking Water Regulation
i. Summary of Major Comments on the Uranium Options
(1) Costs and Benefits of Uranium MCLs of 20, 40, and 80 g/L or pCi/L
(2) The Calculation of the Safe Level for Uranium in Water
(3) Compliance Options for Small Systems for an MCL of 20 g/L or pCi/L
(4) The Use of a Dual Standard for Uranium
3. Retaining Beta Particle and Photon Radioactivity MCL
a. Summary of Major Comments Regarding the Decision to Retain
the Current Beta Particle and Photon Radioactivity MCL
4. Retaining the Current Gross Alpha Particle Activity MCL
a. Summary of Major Comments Regarding the Decision to Retain
the Current Definition of the (Adjusted) Gross Alpha Particle Activity MCL
5. Further Study of Radium-224
a. Summary of Major Comments on Radium-224
(1) The Use of a Short Gross Alpha Particle Activity Sample
Holding Time to Measure Radium-224
(2) The Need to Regulate Radium-224
6. Entry Point Monitoring and the Standardized Monitoring Framework
7. Separate Monitoring for Radium-228 and Change to Systems
Required to Monitor for Beta Particle and Photon Radioactivity
8. Future Actions Regarding the Regulation of Radionuclides at
Non-Transient Non-Community Water Systems
a. Summary of Major Comments on NTNCWSs and EPA Responses
E. What are the health effects that may result from exposure to
radionuclides in drinking water?
1. Major Comments
a. Linear Non-threshold Model
b. Radium Carcinogenicity Threshold
c. ``Beneficial Effects'' of Radiation
F. Does this regulation apply to my water system?
G. What are the final drinking water regulatory standards for
radionuclides (Maximum Contaminant Level Goals and Maximum
Contaminant Levels)?
H. What are the best available technologies (BATs) for removing
radionuclides from drinking water?
I. What analytical methods are approved for compliance
monitoring of radionuclides?
1. Major Comments
a. Request for ICP-MS Method for Uranium
b. Detection Limit for Uranium
J. Where and how often must a water system test for radionuclides?
1. Monitoring frequency for gross alpha, radium 226, radium 228,
and uranium:
2. Monitoring frequency for beta particle and photon radioactivity:
3. Sampling points and data grandfathering
4. Does the rule allow compositing of samples?
5. Interpretation of Analytical Results
K. Can my water system use point-of-use (POU), point-of-entry
(POE), or bottled water to comply with this regulation?
L. What do I need to tell my customers?
1. Consumer Confidence Reports
2. Public Notification
M. Can my water system get a variance or an exemption from an
MCL under today's rule?
N. How were stakeholders involved in the development of this rule?
O. What financial assistance is available for complying with
this rule?
P. How are the radionuclides MCLs used under the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA)?
Q. What is the effective date and compliance date for the rule?
R. Has EPA considered laboratory approval/certification and
laboratory capacity?
1. Laboratory Approval/Certification
2. Laboratory Capacity: Laboratory Certification and PT Studies
3. Summary of Major Comments Regarding Laboratory Capacity and
EPA Responses
a. Laboratory Certification, Availability of PT Samples and
Costs of PT Samples:
b. Laboratory Capacity:
II. Statutory Authority and Regulatory Background
A. What is the legal authority for setting National Primary
Drinking Water Regulations (NPDWRs)?
B. Is EPA required to finalize the 1991 radionuclides proposal?
III. Rule Implementation
A. What are the requirements for primacy?
B. What are the special primacy requirements?
C. What are the requirements for record keeping?
D. What are the requirements for reporting?
E. When does a State have to apply for primacy?
F. What are Tribes required to do under this regulation?
IV. Economic Analyses
A. Estimates of Costs and Benefits for Community Water Systems
B. Background
1. Overview of the 1991 Economic Analysis
2. Summary of the Current Estimates of Risk Reductions,
Benefits, and Costs
3. Uncertainties in the Estimates of Benefits and Cost
a. Uncertainties in Risk Reduction and Benefits Estimates
b. Uncertainty in Compliance Cost Estimates
4. Major Comments
a. Retention of radium-226/-228 MCL of 5 pCi/L
b. Cost/Benefit Analysis Requirements
c. Cumulative Affordability
d. Disposal costs
e. Discounting of Costs and Benefits
f. Use of MCLs for Ground Water Protection Needs to be Evaluated
as Part of this Rulemaking
V. Other Required Analyses and Consultations
A. Regulatory Flexibility Act (RFA)
B. Paperwork Reduction Act
C. Unfunded Mandates Reform Act
1. Summary of UMRA Requirements
D. National Technology Transfer and Advancement Act
E. Executive Order 12866: Regulatory Planning and Review
F. Executive Order 12898: Environmental Justice
G. Executive Order 13045: Protection of Children from
Environmental Health Risks and Safety Risks
H. Executive Order 13084: Consultation and Coordination with
Indian Tribal Governments
I. Executive Order 13132
J. Consultation with the Science Advisory Board and the National
Drinking Water Advisory Council
K. Congressional Review Act

I. Background and Summary of the Final Rule

A. What Did EPA Propose in 1991?

In 1991, EPA proposed a number of changes and additions to the
radionuclides NPDWRs. Among other things, EPA proposed to:
Set a maximum contaminant level goal (MCLG) of zero for
all radionuclides.
Set a maximum contaminant level (MCL) of 20 g/L
or 30 pCi/L for uranium (with options of 5 pCi/L to 80 g/L).
Change the radium standard from a combined limit for
radium-226 and 228 of 5 pCi/L to separate standards at 20 pCi/L.
Remove radium-226 from the radionuclides included in the definition

[[Page 76710]]

of gross alpha, while keeping the gross alpha MCL at 15 pCi/L, since
the proposed radium-226 MCL was greater than the gross alpha MCL.
Change dose limit from critical organ dose (millirems) to
``weighted whole body dose'' (millirems-effective dose equivalent).
Require community water systems which are determined by
the State to be vulnerable or contaminated to monitor for beta particle
and photon radioactivity, rather than at all surface water systems
serving a population over 100,000 people (as under the current 1976 rule).
Establish a monitoring framework more in line with the
standardized monitoring framework used for other contaminants.
Exclude compositing for beta particle and photon emitters.
Include non-transient, non-community water systems
(NTNCWSs) in the regulation.
Require that each entry point to the distribution system
be monitored to ensure that each household in the system received water
protective at the MCL.

B. Why Did EPA Propose Changes to the Radionuclides Drinking Water
Regulations in 1991?

In 1976, National Interim Primary Drinking Water Regulations were
promulgated for radium-226 and -228, gross alpha particle radioactivity
and beta particle and photon radioactivity. The health risk basis for
the 1976 radionuclides MCLs was described in the recent radionuclides
Notice of Data Availability (NODA), (65 FR 21575, April 21, 2000). The
1986 reauthorization of the Safe Drinking Water Act (SDWA) required EPA
to promulgate MCLGs and National Primary Drinking Water Regulations
(NPDWRs) for the above radionuclides, radon and uranium. Also in 1986,
EPA published an Advance Notice of Proposed Rulemaking for the
radionuclides NPDWRs (EPA 1986), which stated EPA's intent to
accomplish this goal. In 1991, EPA proposed changes to the current
radionuclides standards and new standards for radon and uranium. EPA
determined that both combined radium-226 and -228 and uranium could be
analytically quantified and treated to 5 pCi/L. However, EPA concluded
that, given the much greater cost-effectiveness of reducing risk
through radon water treatment relative to radium and uranium, the
feasible levels were 20 pCi/L each for radium-226 and -228 and 20
g/L (or 30 pCi/L) for uranium. Between 1986 and 1991, EPA made
risk estimates based on then-current models and information, as
described in the NODA (EPA 2000e) and its Technical Support Document
(USEPA 2000h). The 1991 risk estimates \1\ indicated that the proposed
MCL changes would result in lifetime cancer risks within the risk range
of 10-6 and 10-4 (one in one million to one in
ten thousand) that EPA considers in establishing NPDWRs. The 1991
proposed uranium MCL was based on both kidney toxicity risk and cancer
risk. All MCLGs for radionuclides were proposed as zero pCi/L, based on
a linear no-threshold cancer risk model for ionizing radiation. A
summary of the difference between the 1976 rule and the 1991 proposal
are presented in Table I-1. The detailed differences between the 1976
rule and the 1991 proposal can be found in the record for this
rulemaking (EPA 1976; 1986; 1991; 2000a).
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\1\ The 1991 cancer risk estimates were based on the now-
outdated RADRISK model (see the NODA and its Technical Support
Document, USEPA 2000e and h).

Table I-1.--Comparison of the 1976 Rule, 1991 Proposal, and 2000 Final Rule
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Provision 1976 rule (current rule) 1991 proposal 2000 final rule
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Affected Systems................. CWS...................... CWS + NTNC.............. CSW.
MCLG for all radionuclides....... No MCLG.................. MCLG of zero............ MCLG of zero.
Radium MCL....................... Combined Ra-226 + Ra-228 Ra-226 MCL of 20 pCi/L.. Maintain current MCL
MCL of 5pCi/L. Ra-228 MCL of 20 pCi/L.. based on the newly
estimated risk level
associated with the
1991 proposed MCL.
Beta/Photon Radioactivity MCL.... 4 4 mrem/y Maintain current MCL
mrem/y to the total body effective dose based on the newly
or any given internal equivalent (ede) estimated risk level
organ Re-derived associated with the
Except for H-3 radionuclide-specific 1991 proposed MCL. This
and Sr-90, derived activity concentrations MCL will be reviewed
radionucide-specific yielding 4 mrem/y ede within 2 to 3 years
activity concentrations based on EPA RADRISK based on a need for
yielding 4 mrem/y based code and 2 L/d. further re-evaluation
on NSB Handbood 69 and Total dose from of risk management
2L/d. co-occurring beta/ issues.
H-3 = 20,000 pCi/ photon emitters must be
L; Sr-90 = 8 pCi/L. 4 mrem/y ede.
Total dose from
co-occurring beta/photon
emitters must be 4 mrem/y to the
total body of any
internal organ.
Gross alpha MCL.................. 15 pCi/L excluding U and ``Adjusted'' gross aplha Maintain current MCL
Rn, but including Ra-226. MCL of 15 pCi/L, based on the newly
excluding Ra-226, estimated risk level
radon, and uranium. associated with the
1991 proposed MCL.
Polonium-210..................... Included in gross alpha.. Included in gross alpha. Included under gross
alpha, as in current
rule. Monitoring
required under the UCMR
rule. Further action
may be proposed at a
later date.
Lead-210......................... Not Regulated............ Included in beta No changes to current
particle and photon rule. Monitoring
radioactivity; required under the UCMR
concentration limit rule. Further action
proposed at 1 pCi/L. may be proposed at a
later date.
Uranium MCL...................... Not Regulated............ 20 g/L or 30 pCi/L w/ 30 /L.
option for 5 pCi/L-80 g/
L.

[[Page 76711]]

Ra-224........................... Part of gross alpha, but Part of gross alpha, but No changes to current
sample holding time too sample holding time too gross alpha rule. Will
long to capture Ra-224. long to capture Ra-224. collect national
occurrence information;
further action may be
proposed at a later
date.
Radium monitoring................ Ra-226 linked to Ra-228; Measure Ra-226 and -228 Measure Ra-226 and -228
measure Ra-228 if Ra-226 separately. separately.
> 3 pCi/L and sum.
Monitoring baseline.............. 4 quarterly measurements. Annual samples for 3 Implement Std Monitoring
Monitoring reduction years; Std Monitoring Framework as proposed
based on results: > 50% Framework: > 50% of MCL in 1991. Four initial
of MCL required 4 required 1 sample every consecutive quarterly
samples every 4 yrs; 3 years; 50% of MCL samples in first cycle.
50% of MCL reguired 1 enabled system to apply If initial average
sample every 4 yrs. for waiver to 1 sample level > 50% of MCL: 1
every 9 years. sample every 3 years;
50% of MCL: 1 sample
every 6 years; Non-
detect: 1 sample every
9 years. (beta particle
and photon
radioactivity has a
unique schedule--see
section III, part--K)
States will have
discretion in data
grandfathering for
establishing initial
monitoring baseline.
Beta particle and photon emitters Surface water systems > Ground and surface water CWSs determined to be
monitoring. 100,000 population systems within 15 miles vulnerable by the State
Screen at 50 pCi/L/; of source screen at 30 screen at 50 pCi/L.
vulnerable systems or 50 pCi/K.
screen at 15 pCi/L.
Gross alpha monitoring........... Analyze up to one year Six month holding time As proposed in 1991.
later. for gross alpha
samples; Annual
compositing of samples
allowed.
Analytical Methods............... Provide methods.......... Method updates proposed Current methods with
in 1991; Current clarifications.
methods were updated in
1997.
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C. What New Information Has Become Available Since 1991? Overview of
the 2000 Notice of Data Availability (NODA)

EPA published a Notice of Data Availability (NODA) on April 21,
2000. This NODA described the new information that has become available
since the 1991 proposal and the basis for today's final regulatory
decisions. The most significant source of new information is Federal
Guidance Report-13 (FGR-13) (USEPA 1999b), ``Cancer Risk Coefficients
for Environmental Exposure to Radionuclides,'' which provides the
numerical factors used in estimating cancer risks from low-level
exposures to radionuclides. The risk coefficients in FGR-13 are based
on state-of-the-art methods and models and are a significant
improvement over the risk coefficients that supported the 1991
radionuclides proposal. FGR-13 is the latest report in a series of
Federal guidance documents that are intended to provide Federal and
State agencies technical information to assist their implementation of
radiation protection programs. FGR-13 was formally reviewed by EPA's
Science Advisory Board and was peer-reviewed by academic and government
radiation experts. An interim version of the report was published for
public comment in January of 1998. Comments were provided by Federal
Agencies, including the Nuclear Regulatory Commission and the
Department of Energy, State Agencies, and the public. The final version
(September 1999) reflects consideration of all of these comments. The
risk analyses supporting today's regulatory decisions are described in
detail in the NODA (EPA 2000e) and its Technical Support Document
(USEPA 2000h).
The NODA also reported the results from a June 1998 USEPA workshop
held to discuss non-cancer toxicity issues associated with exposure to
uranium from drinking water. At this workshop, a panel of experts
reviewed and evaluated new information regarding kidney toxicity was
examined. The findings from this workshop can be found in the NODA's
Technical Support Document (USEPA 2000h).
Other important new information includes the results from a 1998
U.S. Geological Survey study which targeted the occurrence of radium-
224 and beta particle/photon radioactivity (USEPA 2000e and h).
Previously, it was assumed that the alpha-emitting radium-224 isotope
rarely occurred in drinking water. If present in drinking water,
because of its short half-life (3.6 days) and estimated low occurrence,
it was thought that sufficient time would elapse to allow the isotope
to decay to low levels before entry into the distribution system.
Hence, radium-224 was not thought to appreciably occur in drinking
water. This new information indicates that radium-224 significantly
(positively) correlates with both radium-228 (correlation coefficient
of 0.82) and radium-226 (correlation coefficient of 0.69), suggesting
that radium-224 should be evaluated as a potential drinking water
contaminant of national concern (USEPA 2000h). The impact of this and
other information on decisions regarding radium-224 is discussed in
part D of this section. In addition to the radium-224 occurrence
information, the USGS study also determined that the majority of the
beta particle/photon radioactivity in the samples collected was due to
the presence of radium-228 and potassium-40, both naturally occurring
contaminants. Since radium-228 is regulated under the combined radium-
226/-228 standard and potassium-40 is not regulated, this suggests that
most situations in which the beta/photon screening level is exceeded
will not result in MCL violations. Of more concern, minor contributions
from naturally occurring lead-210 were also reported. Lead-210
occurrence will be studied under the Unregulated Contaminant Monitoring
Rule (UCMR).
In addition to this new technical information, the NODA also
described the 1996 changes to the statutory framework for setting
drinking water NPDWRs. The SDWA, as amended in 1996, requires EPA to
review and revise,

[[Page 76712]]

as appropriate, each national drinking water regulation at least once
every six years. The Act also requires that any revision to an NPDWR
``maintain, or provide for greater, protection of the health of
persons'' (section 1412(b)(9)).
Regarding the setting of new NPDWRs, the SDWA as amended in 1996
gives EPA the flexibility to set an MCL at a level less stringent than
the feasible level, if the Administrator determines that the benefits
do not justify the costs at the feasible level. If the Administrator
makes this finding, the Act directs EPA to set the MCL at a level that
``maximizes health risk reduction benefits at a cost that is justified
by the benefits'' (section 1412(b)(6)). This provision applies to
uranium only, since it is the only contaminant for which a new MCL is
being established by today's regulatory action.

D. What Are the Rationales for the Regulatory Decisions Being
Promulgated Today?

As previously discussed, EPA is retaining the current MCLs for
combined radium-226 and 228, gross alpha particle radioactivity, and
beta particle and photon radioactivity and is promulgating a new
standard for uranium. The following is a discussion of the rationales
supporting these decisions. In addition to the responses to major
comments in the following section, responses to each individual comment
are in the comment response document which is available for review in
the docket for this final rule.
1. Retaining the Combined Radium-226 and Radium-228 MCL
The 1991 proposed changes to the MCLs for combined radium-226 and
radium-228 were premised on a cost-effectiveness trade-off between
radium mitigation and radon mitigation (a radon standard was also
included in the 1991 proposal). This cost-effectiveness argument was
used to support a proposal to raise the combined radium-226/-228 MCL of
5 pCi/L to individual MCLs of 20 pCi/L for each isotope. At the time,
it was thought that the risks associated with 20 pCi/L of radium-226
and radium-228 were within the 10-6 to 10-4 risk
range. However, current risk analyses based on Federal Guidance Report-
13 (see Part C of this section) indicate that these higher MCLs have
associated risks that are well above the 10-6 to
10-4 risk range. For details on the basis and findings of
this risk analysis, see the NODA (USEPA 2000e) and its Technical
Support Document (USEPA 2000h). Since this proposed change would
introduce higher risks than envisioned in the original 1976 rule,
approaching lifetime cancer risks of one in one thousand
(10-3) for occurrence at or near the 1991 proposed MCLs, EPA
believes that its decision to retain the current combined radium-226/-
228 MCL of 5 pCi/L is justified. Under the 1996 Amendments to the Safe
Drinking Water Act, EPA is required to ensure that any revision to a
drinking water regulation maintains or provides for greater protection
of the health of persons (section 1412(b)(9)).
a. Major Comments Regarding Retention of the Combined Radium-226 and
Radium-228 MCL
The major comments and responses concerning the retention of the
combined radium-226 and radium-228 MCL are summarized in part E of this
section (``What are the health effects that may result from exposure to
radionuclides in drinking water?'').
2. The Final Uranium MCL
a. What Is the Final MCL for Uranium and the Rationale for That
Regulatory Level?
With today's rule, EPA is promulgating a uranium MCL of 30
g/L. The SDWA generally requires that EPA set the MCL for each
contaminant as close as feasible to the MCLG, based on available
technology and taking costs to large systems into account. The 1996
amendments to the SDWA added the requirement that the Administrator
determine whether or not the quantifiable and non-quantifiable benefits
of an MCL justify the quantifiable and non-quantifiable costs based on
the Health Risk Reduction and Cost Analysis (HRRCA) required under
section 1412(b)(3)(C). The 1996 SDWA amendments also provided new
discretionary authority for the Administrator to set an MCL that is
less stringent than the feasible level if the benefits of an MCL set at
the feasible level would not justify the costs (section 1412(b)(6)).
This final rule establishing an MCL for uranium of 30 g/L is
the first time EPA has invoked this new authority.
In conducting this analysis, EPA considered all available
scientific information concerning the health effects of uranium,
including various uncertainties in the interpretation of the results,
as well as all costs and benefits, both quantifiable and non-
quantifiable. As discussed in more detail below, all health endpoints
of concern were considered in this analysis. For some of these, the
risk can currently be quantified (i.e., expressed in numerical terms);
and for some, it cannot. Similarly, there are a variety of health and
other benefits attributable to reductions in levels of uranium in
drinking water, some of which can be monetized (i.e., expressed in
monetary terms) and others that cannot yet be monetized. All were
considered in this analysis. A detailed discussion of each of the
principal factors considered follows.
b. MCLG and Feasible Level for Uranium
Since uranium is radioactive and EPA uses a non-threshold linear
risk model for ionizing radiation, today's rule sets the MCLG (non-
enforceable health-based goal) for this contaminant at zero. The Safe
Drinking Water Act requires EPA to set the MCL as close to the MCLG as
is feasible, where this is defined as ``feasible with the use of the
best technology, treatment techniques and other means which the
Administrator finds, after examination for efficacy under field
conditions and not solely under laboratory conditions, are available
(taking cost into consideration) * * * '' [section 1412(b)(4)(D)]. EPA
proposed a feasible level of 20 g/L in its 1991 proposal. In
doing so, EPA determined that uranium may be treatable and quantifiable
at levels below 20 g/L, however, levels below 20 g/L
were not considered feasible under the Safe Drinking Water Act. EPA
believes the feasible level is still 20 g/L.
c. Basis for 1991 Proposed MCL and Cancer Risk from Uranium
EPA is required by the Safe Drinking Water Act (section 1412(b)(2))
to regulate uranium in drinking water. In 1991, EPA proposed a uranium
MCL of 20 g/L (``mass concentration'') based on health effects
endpoints of kidney toxicity and carcinogenicity. In the proposal, EPA
estimated that 20 g/L would typically \2\ correspond to 30
pCi/L (``activity''), based on an assumed mass:activity ratio of 1.5
pCi/g. While such values are known to occur in ground water,
this conversion factor does not reflect our ``best estimate'' today.
The best estimate of a geometric average mass:activity ratio is 0.9
pCi/g for values near the MCL, based on data from the National
Inorganics and Radionuclides Survey (see USEPA 2000h). Given the
closeness of this

[[Page 76713]]

value to unity (1 pCi/g), the available data suggests that, to
a first approximation \3\, the mass:activity ratio is 1:1 for typical
systems. The 1991 proposed MCL of 20 g/L was determined, at
that time, to correspond to a ``drinking water equivalent level'' (DWEL
\4\) with respect to kidney toxicity for a lifetime exposure. The
corresponding 30 pCi/L level (based on the 1991 mass to activity
conversion) was estimated to have a lifetime cancer risk of slightly
below the 10-\4\ level.
---------------------------------------------------------------------------

\2\ The actual relationship between mass concentration
(g/L) and activity (pCi/L) varies somewhat in drinking
water sources, since the relative amounts of the radioactive
isotopes that make up naturally occurring uranium (U-238, U-235, and
U-234) vary between drinking water sources. The typical conversion
factors that are observed in drinking water range from 0.67 up to 1.5 pCi/g.
\3\ This is mentioned since, for the sake of simplicity, the
reader may thus easily convert between g/L and pCi/L.
However, in current calculations, we use the geometric mean from the
NIRS data, which is 0.9 pCi/g. We reiterate that conversion
factors ranging from 0.67 up to 1.5 pCi/g do occur in
drinking water sources.
\4\ The drinking water equivalent level (DWEL) (g/L) is
the best estimate of the drinking water concentration that results
in the Reference Dose (g/kg/day), assuming a water
ingestion rate of 2 L/day and a body mass of 70 kg.
---------------------------------------------------------------------------

Because the kidney toxicity health effects and the corresponding
non-quantifiable kidney toxicity benefits are a very important
consideration in setting the MCL, we first provide background on these
effects before discussing the rationale for setting the uranium MCL.
d. Uranium Health Effects: Kidney Toxicity
Each kidney consists of over a million nephrons, the filtration
functional units of the kidney. The nephron consists of glomeruli,
which filter the blood, and renal tubules (proximal, distal, collecting
duct, etc.), which collect the fluid that passes through the glomeruli
(the ``filtrate''). After the filtrate flows into renal tubules,
glucose, proteins, sodium, water, amino acids, and other essential
substances are reabsorbed, while wastes and some fraction of
electrolytes are left behind for later excretion. The efficiency of
this process can be monitored by analyzing urine (``urinalysis''),
which reveals the concentrations of the various constituents making up
the urine. For example, protein or albumin in the urine (proteinuria or
albuminuria) indicates reabsorption deficiency or leakage of albumin, a
class of proteins found in blood and which are responsible for
maintaining fluid balance between blood and body cells. In the case of
uranium toxicity, it is not clear whether long-term exposure may lead
to marked albumin loss.
The level of proteinuria in urine is an indication of the degree of
kidney toxicity: levels are divided into ``trace'', ``mild'',
``moderate'', or ``marked'', which are defined by increasing levels of
proteinuria. Increased excretion of protein in the urine could be the
result of tubular damage, inflammation, or increased glomerular
permeability. It should be noted that a gradual loss of nephrons is
asymptomatic until the loss is well advanced; the kidneys normally have
the ability to compensate for nephron-loss. For example, chronic renal
failure occurs when there is around 60% nephron loss. During the
gradual loss of functioning nephrons, the remaining nephrons appear to
adapt, increasing their capacity for filtration, reabsorption, and
excretion.
Uranium has been identified as a nephrotoxic metal (kidney
toxicant), exerting its toxic effects by chemical action mostly in the
proximal tubules in humans and animals. However, uranium is a less
potent nephrotoxin than the classical nephrotoxic metals such as
cadmium, lead, and mercury. Uranium has an affinity for renal proximal
tubular cells and interferes with reabsorption of proteins, as
previously described. Specifically, uranium-induced renal tubular
dysfunction in humans is marked by mild proteinuria, due to reduced
reabsorption in the proximal renal tubules. Furthermore, the
pathogenesis of the kidney damage in short-term animal studies
indicates that regeneration of the tubular cells may occur upon
discontinuation of exposure to uranium. We do not know if uranium-
induced proteinuria is an indicator of the beginning of an adverse
effect or whether it is a reversible effect that does not typically
result in kidney disease. Based on the uncertainty involved in the
ultimate effects, the scientists at our experts workshop (discussed
next) treated this effect as an indicator of an incipient change in
kidney function that may lead ultimately to frank adverse effects such
as breakdown of kidney tubular function. For general information on
proteinuria, kidney function, and kidney disease, see the fact sheets
at ``http://www.niddk.nih.gov/health/kidney/pubs/ proteinuria/
proteinuria.htm'', ``http://www.niddk.nih.gov/health/kidney/pubs/
yourkids/index.htm'', and ``http://www.niddk.nih.gov/health/kidney/
kidney.htm'' (NIH 2000a, NIH 2000b, and NIH 2000c).
e. New Kidney Toxicity Analyses Announced in the NODA
Since the 1991 radionuclides proposal, EPA has re-evaluated the
available kidney toxicity data and, based on the results of an experts
workshop (see the NODA, USEPA 2000e, for details), has estimated the
DWEL to be 20 g/L. The DWEL is derived from the Reference Dose
(RfD), which is an estimate of a daily ingestion exposure to the
population, including sensitive subgroups, that is likely to be without
an appreciable risk of deleterious effects during a lifetime. The RfD
(in g of uranium per kg of body mass per day; g/kg/
day) for uranium was calculated from the Lowest Observed Adverse
Effects Level (``LOAEL''), which is the lowest level at which adverse
effects were observed to occur. The LOAEL is taken directly from health
effects data. The RfD is calculated by dividing the LOAEL by a
numerical uncertainty factor which accounts for areas of variability in
human populations because of uncertainty in the uranium health
database. EPA followed the recommended methodology of the National
Academy of Sciences in estimating the uncertainty factor.
As described in the NODA, we reported that our best-estimate of the
LOAEL is 60 g/kg/day, based on rat data. In support of this
estimate of the DWEL, EPA has some human data which demonstrates that
mild proteinuria has been observed at drinking water levels between 20
and 100 g/L. In estimating the RfD, we have used an
uncertainty factor of 100 (rounded from the product of 3 for intra-
species variability, 10 for inter-species variability, and 3 for the
use of a LOAEL). Using this uncertainty factor, the RfD is calculated
to be 0.6 g/kg/day. The estimated uncertainty in the RfD spans
an order of magnitude (a factor of ten). The 20 g/L DWEL is
calculated by using this RfD and assuming that an adult with a body
mass of 70 kilograms drinks 2 liters of water per day \5\ and that 80%
of exposure to uranium is from water. These calculations are described
in more detail in the NODA's Technical Support Document (USEPA 2000h).
---------------------------------------------------------------------------

\5\ The standard assumptions for the DWEL are conservative,
since the ingestion rate is at the 90th percentile, while the body
mass is more typical. Conservative assumptions are used to ensure
that the resulting exposure level is protective of individuals that
consume significantly more water than typical and children (low body
masses).
---------------------------------------------------------------------------

The Agency believes that 30 g/L is protective against
kidney toxicity. While 20 g/L is the Agency's best estimate of
the DWEL, there are several reasons, in the Agency's judgment, that
demonstrate that there is not a predictable difference in health
effects due to exposure between the DWEL of 20 g/L and a level
of 30 g/L. For instance, variability in the normal range for
proteinuria in humans is very large and there is additional variability
in proteinuria levels observed at uranium

[[Page 76714]]

exposures large enough to induce the effect. In the existing few
epidemiology studies, each of which are based on small study
populations, there were some persons exposed to over five times the
DWEL of 20 g/L without the observation of effects more serious
than mild proteinuria (within the high end of the normal range). An MCL
of 30 g/L represents a relatively small increase over the DWEL
compared to the over-all uncertainty in the RfD and the uncertainty in
the importance of the mild proteinuria observed for uranium exposures
from high drinking water levels (keeping in mind that, as discussed
previously, the DWEL is based on the RfD and is an estimate of a no
effect level for a population). While it is assumed that risk of an
effect (here a mild effect) increases as exposure increases over the
RfD, it is not known at what exposure an effect is likely. Given that
the uncertainty factor of 100 provides a relatively wide margin of
safety, the likelihood of any significant effect in the population at
30 g/L is very small. EPA, thus, believes that the difference
in kidney toxicity risk for exposures at 20 g/L versus 30 g/L is
insignificant.
f. Costs and Benefits From Regulating Uranium in Drinking Water
As discussed in the NODA, EPA has estimated the risk reductions,
monetized benefits, and costs associated with compliance with an MCL of
20 g/L, 40 g/L, and 80 g/L. In the NODA, EPA
solicited comment on using its statutory authority provided in section
1412(b)(6) of the Safe Drinking Water Act to set the uranium MCL at a
level higher than the proposed level of 20 g/L, based on its
analysis of costs and benefits.
The monetized costs and benefits associated with various MCL
options are discussed further in section IV of today's notice and in
more detail in the economic analysis support document (USEPA 2000g).
Table I-2 shows incremental annual cancer risk reductions, total
national annual compliance costs and monetized benefits (excluding
kidney toxicity benefits), and the numbers of community water systems
predicted to have MCL violations for MCLs of 80, 30, and 20 g/
L (assuming the 0.9 pCi/g conversion factor for estimating
cancer risk reductions and benefits). Keeping in mind that the
monetized benefits and risk reductions exclude kidney toxicity
benefits, several things can be noted from the analysis. Focusing on
the MCL change from 30 g/L to 20 g/L (see lower part
of table I-2), one can see that the incremental benefits for
implementing an MCL of 30 g/L are three times greater than the
incremental benefits for a lower MCL of 20 g/L, while the
incremental annual costs are much closer in magnitude ($54 million vs.
$39 million). In terms of incremental cancer cases avoided, the
estimated number of cancer cases avoided for an MCL of 30 g/L
is 0.8 annually, while lowering the MCL to 20 g/L would result
in an additional 0.2 cases avoided annually (25% reduction) at an
additional cost of $39 million annually (75% increase). Approximately
37% of systems predicted to have MCL violations occur between 30
g/L and 20 g/L, resulting in significant increases in
annual compliance costs (42% of national compliance costs occur between
30 g/L and 20 g/L), while the number of cancer cases
avoided increases much less significantly (only 20% of cancer risk
reduction occurs between 30 g/L and 20 g/L).
Since the kidney benefits are not quantified, this is an incomplete
picture, but EPA believes that the uncertainties in the analysis of
health effects are such that it is not known whether the risk of mild
proteinuria are appreciably different between 20 g/L and 30
g/L. Assuming that there is a risk increase, it would be
expected to be negligible compared to the risk increase that occurs
between the highest uranium levels that occur in drinking water (i.e.,
approximately 200 g/L) and an MCL of 30 g/L.
Considering only cancer risk reduction benefits, the annual net
benefits \6\ for a uranium MCL of 20 g/L are negative $90
million \7\ and for an MCL of 30 g/L are negative $50 million.
Since the cancer risk reduction net benefits are higher at 30
g/L than at 20 g/L and the non-quantified kidney
toxicity benefits are expected to be substantially the same at 20
g/L and 30 g/L, EPA believes an MCL of 30 g/
L maximizes the benefits at a cost justified by the benefits. EPA does
not believe that uranium levels above 30 g/L are protective of
kidney toxicity with an acceptable margin of safety. (EPA believes that
the margin of safety associated with a 30 g/L are comparable
with those at 20 g/L.) Further, EPA believes that the net
kidney toxicity benefits of an MCL greater than 30 g/L would
be less than those at 30 g/L. Finally, EPA believes that 30
g/L is protective of the general population, including children and the
elderly.
---------------------------------------------------------------------------

\6\ Not incremental net benefits, but net benefits: ``Benefits
for an MCL in isolation''--``Cost of an MCL in isolation''.
\7\ Annual net benefits for an MCL of 20 g/L = $4
million--$93 million, which rounds to negative $90 million; annual
net benefits for an MCL of 30 g/L = $3 million--$54
million, which rounds to negative $50 million. See Table IV-1,
``Summary of Costs and Benefits for Community Water Systems
Predicted to Be Impacted by the Regulatory Options Being Considered
for Finalization'', in today's notice and the supporting Economic
Analysis (USEPA 2000g) for more details.

Table I-2.--Incremental Costs and Benefits for Uranium MCLs of 80 g/L, 30 g/L, and 20 g/L
--------------------------------------------------------------------------------------------------------------------------------------------------------
Incremental
Incremental annual monetized Incremental
Incremental annual cancer benefits number of
Uranium MCL Exposure change annual cancer compliance (kidney benefits community water
cases avoided costs (in not monetized) systems
millions) (in millions) impacted
--------------------------------------------------------------------------------------------------------------------------------------------------------
80 g/L............................ -80 g/L 0.5 $16 $2 100
30 g/L............................ 80-30 g/L 0.4 38 1 400
20 g/L............................ 30-20 g/L 0.2 39 1 290
--------------------------------------------------------------------------------------------------------------------------------------------------------
Incremental Costs and Benefits for Uranium MCLs of 30 g/L (g/L) and 20 g/L only
--------------------------------------------------------------------------------------------------------------------------------------------------------
30 g/L............................ -30 g/L 0.8 54 3 500
20 g/L............................ 30-20 g/L 0.2 39 1 290
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Numbers are rounded, so numbers resulting from addition and subtraction of the numbers shown may appear to yield incongruous results. However, the
numbers shown are calculated using more significant figures and rounded after, which is the appropriate approach for numbers with large uncertainties.

[[Page 76715]]

g. Administrator's Decision To Promulgate MCL Higher Than Feasible Level
Based on the relatively modest annual cancer risk reductions and
the expected modest kidney toxicity risk reductions between 30
g/L and 20 g/L (see Table I-2) and the high annual
compliance costs for an MCL of 20 g/L, the Administrator has
determined that the benefits do not justify the costs at the feasible
level. Furthermore, as previously described, the Administrator has
determined that an MCL of 30 g/L maximizes the health risk
reduction benefits at a cost justified by the benefits. In summary,
this finding is based on the fact that potential uranium MCLs lower
than 30 g/L have substantially higher associated compliance
costs and only modest additional cancer risk reduction and kidney
toxicity benefits. EPA has not selected a higher MCL for several
reasons. Higher uranium MCLs would still incur implementation and
monitoring costs, with benefits greatly diminished because uranium does
not occur significantly at levels much higher than 30 g/L.
Additionally, EPA believes that a uranium MCL of 30 g/L is
appropriate since it is protective of kidney toxicity and cancer with
an adequate margin of safety. We do not believe that MCL options higher
than 30 g/L afford a sufficient measure of protection against
kidney toxicity.
Assuming a conversion factor of 0.9 pCi/g, an MCL of 30
g/L will typically correspond to 27 pCi/L, which has a
lifetime radiogenic cancer risk of slightly less than one in ten
thousand, within the Agency's target risk range of one in one million
to one in ten thousand. EPA is aware that circumstances may exist in
which more extreme conversion factors (> 1.5 pCi/g) apply. EPA
does not have extensive data on these ratios at local levels, but
believes these higher ratios to be rare. In these rare circumstances,
uranium activities in drinking water may exceed 40 pCi/L. Although
these concentrations are still within EPA's target risk ceiling of
1 x 10-4, EPA recommends that drinking water systems subject
to extreme pCi/g conversion factors mitigate uranium levels to
30 pCi/L or less, to provide greater assurance that adequate protection
from cancer health effects is being afforded.
In today's final rule, the Administrator is exercising her
authority to set an MCL at a level higher than feasible (section
1412(b)(6)), based on the finding that benefits do not justify the
costs at the feasible level (20 g/L) and that the net benefits
are maximized at a level (30 g/L) that is still protective of
kidney toxicity and carcinogenicity with an adequate margin of safety.
EPA believes that there are considerable non-quantifiable benefits
associated with ensuring that kidney toxicity risks are minimized and
has weighed these non-quantifiable benefits in its decision to exercise
its discretionary authority under SDWA section 1412(b)(6).
In invoking the discretionary authority of section 1412(b)(6) to
set an MCL level higher than feasible, the Agency is in compliance with
the provisions of section 1412(b)(6)(B). This provision provides that
the judgment with respect to when benefits of the regulation would
justify the costs under subparagraph (6)(A) is to be made based on
assessment of costs and benefits experienced by persons served by large
systems and those other systems unlikely to receive small system
variances (e.g. systems serving up to 10,000 persons). In effect, the
costs to systems likely to receive a small system variance are not to
be considered in judging the point at which benefits justify costs.
Subparagraph (6)(B) also provides, however, that this adjusted
assessment does not apply in the case of a contaminant found ``almost
exclusively'' in ``small systems eligible'' for a small system
variance. Because the contaminants addressed in today's rule are found
almost exclusively in small systems and because the Agency has
identified affordable treatment technologies for small systems that
would need to comply with today's rule (i.e., we do not contemplate
granting small system variances), the Agency has not adjusted the
proposed MCL pursuant to subparagraph (B).
h. California Drinking Water Regulation
Approximately one-third of the community water systems that are
expected to be impacted by the uranium MCL are located in California.
Thus, current and likely future practices of these systems is of
particular interest. The State of California currently has a drinking
water standard for uranium of 20 pCi/L (enforced as 35 g/L),
which it adopted in 1989. EPA has used comments and information from
the State of California in considering its MCL for uranium. The
California standard is based on the California Department of Health
Services' 1989 estimate of the DWEL for kidney toxicity, 35 g/
L. While California has recently proposed revising its non-enforceable
public health goal for uranium in drinking water, it is not currently
known what the final estimate will be. In response to the NODA,
representatives of the California Department of Health Services
commented that at uranium levels of 35 g/L, most of its small
water systems were able to use alternate sources of water (new wells)
as a means of complying with the standard, but that 20 g/L
would lead to many of these small systems having to install treatment,
which, because of waste disposal issues (i.e., inability to safely
dispose of hazardous radioactive wastes), could lead to a significant
number of small systems being unable to come into compliance through
treatment. EPA believes that these comments lend support to the choice
of an MCL of 30 g/L as being both protective of kidney
toxicity and a standard that allows for significant use of non-
treatment options by small systems, reducing the need for dealing with
radioactive waste handling and disposal.
i. Summary of Major Comments on the Uranium Options
(1) Costs and Benefits of Uranium MCLs of 20, 40, and 80
g/L or pCi/L: Most commenters stated that the benefits of an
MCL of 20 g/L or pCi/L did not justify the costs and suggested
that EPA should exercise its authority under SDWA section 1412(b)(6) to
set an MCL higher than the feasible level. As discussed previously in
this section, EPA agrees that the benefits of an MCL at 20 g/L
do not justify the costs and has exercised its SDWA authority by
setting the uranium MCL at a level of 30 g/L, a level at which
EPA believes the benefits do justify the costs.
(2) The Calculation of the Safe Level for Uranium in Water: One
commenter suggested that the use of 70 kg as the reference body mass
with a ``90th percentile ingestion rate'' of 2 L/day will lead to a
kidney toxicity DWEL that is more protective than the 90th percentile.
EPA agrees that it is possible that 20 g/L is more protective
than the 90th percentile value for the general population. EPA has
performed a preliminary Monte Carlo analysis of the safe level that
replaces point estimates for consumption rate and body mass with
distributions based on the available data. Based on this analysis the
90th percentile (for the general population) equivalent level could be
as high as 30 g/L.
(3) Compliance Options for Small Systems for an MCL of 20
g/L or pCi/L: Several commenters stated that an MCL of 20
g/L or pCi/L would force small systems to install water
treatment, rather than allowing other compliance options like
installing new wells or blending water. The commenters

[[Page 76716]]

suggested that an MCL of 20 g/L or pCi/L would pose a
significant hardship on small systems with little benefit, including
significant costs and technical problems associated with waste
disposal. Commenters also suggested that a higher MCL would allow a
larger fraction of small systems to use compliance options other than
treatment, most notably, new well installation. EPA agrees that a lower
MCL does decrease the probability that some non-treatment options could
be used, including new well installation and blending. EPA agrees that
the benefits of the MCL of 20 g/L or pCi/L do not justify the
costs and thus has chosen a higher MCL. EPA also believes that an MCL
of 30 g/L should allow a greater fraction of small systems to
use non-treatment options for compliance, avoiding waste disposal
issues and excessive treatment costs.
(4) The Use of a Dual Standard for Uranium: Commenters suggested
that the use of a dual standard for uranium to ensure protectiveness of
both kidney toxicity and carcinogenicity, i.e., one in g/L and
one in pCi/L, would be unnecessarily complicated, since it would
require that both uranium isotopic analyses and mass analyses be
performed by each water system. EPA agrees that a dual standard would
be unnecessarily complicated and has chosen a single standard expressed
in g/L that is protective of both kidney toxicity and carcinogenicity.
3. Retaining Beta Particle and Photon Radioactivity MCL
With today's rule, EPA is retaining the existing MCL for beta and
photon emitters and the methodology for deriving concentration limits
for individual beta and photon emitters that is incorporated by
reference. The concentrations for these contaminants were derived from
a dosimetry model used at the time the rule was originally promulgated
in 1976. When these risks are calculated in accordance with the latest
dosimetry models described in Federal Guidance Report 13, the risks
associated with these concentrations, while varying considerably,
generally fall within the Agency's current risk target range for
drinking water contaminants of 10-4 to 10-6.
Accordingly, we are not changing the MCL for beta particle and photon
radioactivity at this time.
We also are concerned that under the regulatory changes for the
beta particle and photon radioactivity MCL proposed in 1991 \8\) the
concentrations of many individual radionuclides have associated
lifetime cancer morbidity (and mortality) risks that exceed the
Agency's target risk range. A newly proposed MCL expressed in mrem-ede
could result in a more consistent risk level within the Agency's target
risk range. However, in today's final rule, we are ratifying the
current standard since it is protective of public health. At the same
time, we believe a near future review of the beta particle and photon
radioactivity MCL and the methods for calculating individual
radionuclide concentration limits is appropriate. We intend to
reevaluate the MCL under the authority of section 1412(b)(9) of the
SDWA to ensure that the MCL reflects the best available science. This
review will be performed as expeditiously as possible (expected to be 2
to 3 years).
---------------------------------------------------------------------------

\8\ 4 mrem ede with a look-up table of concentrations different
from those calculated using the current MCL and the methodology
incorporated by reference in the current rule.
---------------------------------------------------------------------------

Particular questions that we believe warrant examination as part of
such a reevaluation process would include, but are not limited to, the
following:
What additional beta and photon emitters should be regulated?
What is the appropriate aggregate MCL expression for this
category of radionuclides?
What new information concerning occurrence, analytical
methods, health effects, treatment, costs, and benefits would have a
bearing on this reevaluation?
Is there an advantage to setting individual radionuclide
concentration limits using a ``uniform risk level MCL''?
If the basis of the current MCL changes, is there an
advantage to and legal basis for setting concentration limits for
individual beta particle and photon emitters within a guidance document
that can be readily updated as scientific understanding improves?
To what degree, in keeping with the provisions of sections
1412(b)(9) and 1412(b)(3)(A), can the existing methodology for
calculating the concentration limits of individual beta and photon
emitters be adjusted in accordance with the best available scientific
models and information and still meet the requirement that revised
regulations provide ``greater or equivalent protection to the health of
persons''?
How would any adjustments be reconciled with the
requirement that MCLs be set ``as close as feasible'' to MCLGs?
Finally, we note that there should be no assumption, from the
outset of this reevaluation, that the process will necessarily lead to
a different set of individual beta and photon emitter concentration
limits than those that result from the methodology incorporated by
reference in the current and final rule. This reevaluation will involve
a complicated set of legal, regulatory, and technical information that
will need to be carefully considered.
a. Summary of Major Comments Regarding the Decision To Retain the
Current Beta Particle and Photon Radioactivity MCL
Of the 70 commenters who responded to the April 21, 2000 NODA,
approximately 14 commented on the MCL for beta particle and photon
radioactivity. The commenters represented Federal agencies, State
governments, local governments, water utilities, water associations,
nuclear institute representatives and public interest groups. Seven
commenters support EPA's proposal to retain the current MCL and several
of these commenters agreed that it was appropriate to review the
standard under the six year review process \9\. The commenters that
supported EPA's proposal to maintain this MCL felt there was no
appreciable occurrence of man-made beta emitters in drinking water, so
it was not a pressing public health concern to revise the MCL. Several
of these commenters also felt it was appropriate to delay action on
lead-210 until more occurrence information becomes available.
---------------------------------------------------------------------------

\9\ Six Year Review Process--Under the Safe Drinking Water Act
(SDWA), the U.S. Environmental Protection Agency (EPA) must
periodically review existing National Primary Drinking Water
Regulations (NPDWRs) and, if appropriate, revise them. This
requirement is contained in section 1412(b)(9) of SDWA, as amended
in 1996, which reads, ``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.''
---------------------------------------------------------------------------

Three of the 14 commenters objected to EPA's proposal to retain the
current standard and to defer re-evaluation to the statutorily required
six year process. These commenters felt that the Agency should propose
to update the models used as the basis for the MCL on a shorter time-
frame than the six year review process. The commenters felt that
deferring the reevaluation of beta/photons to the six year review
process would increase and perpetuate the uncertainty involved with
standards which are used in waste management and cleanup decisions. One
commenter pointed out that most DOE sites with

[[Page 76717]]

radiological contamination are moving towards the final Record of
Decision (ROD) stage (as required as part of site clean-up under the
Superfund Program). The commenter felt that delaying the re-evaluation
of this MCL until the next six year review process (2002-2008) would
occur after most RODs were already in place and it would be too late to
incorporate a new MCL into the RODs. The commenter further stated that
some ROD commitments will be using clean up standards based on the 1976
values and if the standards are eventually relaxed, the committed RODs
(which were based on the 1976 values) will be extremely expensive and
may not be justifiable. EPA agrees that review of the MCL for beta
particle and photon radioactivity is a priority and, as previously
discussed in this section, the Agency intends to review this standard
within the general time frame established for the U.S. Department of
Energy's (DOE) submission of the licensing application for the Yucca
Mountain site.
4. Retaining the Current Gross Alpha Particle Activity MCL
In 1991, EPA proposed excluding radium-226 from adjusted gross
alpha particle activity, which is currently defined as the gross alpha
particle activity result minus the contributions from uranium and radon
(in practice, it is not necessary to exclude radon, since it
volatilizes before analysis). The 1991 proposal to increase the
combined radium-226/-228 MCL from 5 pCi/L combined to 20 pCi/L each
made the adjusted gross alpha definition necessary, since the radium-
226 MCL exceeded the adjusted gross alpha particle activity MCL.
Besides addressing this inconsistency, at the time EPA believed that
the unit risk from radium-226 was small enough that the change in the
definition of adjusted gross alpha particle activity would not result
in a significant change in health protectiveness. As discussed in the
NODA, the 1991 risk analysis was based on the EPA RADRISK model, which
is now outdated.
The most current risk analyses are based on FGR-13, discussed
previously in today's preamble and in detail in the NODA and its
Technical Support Document. These new radionuclide cancer risk
coefficients greatly improved health effects analyses indicate that the
unit risk from radium-226 is too significant to exclude radium-226 from
adjusted gross alpha particle activity without an appreciable loss in
health protectiveness. For this reason, today's rule does not change
the definition of adjusted gross alpha from the current rule.
Also, as discussed in the NODA, further occurrence data will be
collected for polonium-210 and radium-224 (discussed in more detail
next) and, based on findings, EPA may propose in the future to address
these and/or other contaminants that contribute to gross alpha particle
activity through changes to the definition of adjusted gross alpha
particle activity. Regardless of the findings concerning polonium-210
and radium-224 occurrence, the gross alpha particle activity standard
will be reviewed under the required six year regulatory review process.
a. Summary of Major Comments Regarding the Decision to Retain the
Current Definition of the (Adjusted) Gross Alpha Particle Activity MCL
Of the 70 commenters who responded to the April 21, 2000 NODA,
approximately 23 commented on issues regarding the gross alpha particle
activity MCL and/or whether or not to regulate polonium-210 and/or
radium-224 separately. The summary of the comments regarding radium-224
is discussed further in the next section. The commenters represented
State governments, local governments, water associations, water
utilities, associations of elected officials and public interest
groups. Of these 23 commenters, 14 stated that EPA should not regulate
polonium-210 and/or radium-224 separately. Some commenters felt either
the occurrence of these radionuclides is rare in water supplies or they
felt that not enough occurrence data was available to warrant separate
limits. EPA agrees that occurrence information should be collected
before proposing separate standards. Commenters felt that occurrence
information should be gathered under an unregulated contaminant
monitoring mechanism, which EPA is doing in the case of polonium-210.
Only one commenter supported an immediate separate standard for
polonium-210 and quick gross alpha particle activity analysis to ensure
that radium-224 was included in gross alpha particle activity
measurement. EPA points out that a proposal would be necessary for such
actions and that a proposal would require adequate occurrence
information. Of those commenters who commented on retaining the current
definition of the gross alpha particle activity MCL, including radium-
226, most supported retaining the standard as is. However, three
commenters stated that radium-226 should not be included in the gross
alpha particle activity MCL, since it is already regulated in the
combined radium-226/-228 standard. EPA points out that the contribution
from radium-226 to the over-all risk from gross alpha particle activity
is significant and that removing it would reduce the health
protectiveness of the gross alpha particle activity standard. Also, two
commenters felt that gross alpha particle activity should only be used
as a screening tool (versus a standard) since the commonly occurring
alpha emitting radionuclides are already covered under other standards.
EPA points out polonium-210 is not regulated under any other standard
at this time. The gross alpha particle activity standard will be
reviewed under six year review and these and other considerations will
be taken into account.
5. Further Study of Radium-224
As discussed in section I.C., recent studies show that there is a
positive correlation between radium-228 and radium-224 (correlation
coefficient of 0.82, approximately 1:1). This correlation means that in
most situations in which a system has high radium-224 levels, it will
also have high radium-228 levels and, with a less degree of certainty,
high radium-226 levels. More details on this relationship, including
the summary statistics, can be found in the NODA and its Technical
Support Document (USEPA 2000e and 2000h). The expected result of these
correlations is that high radium-224 levels will be mitigated by
enforcement of the combined radium-226/-228 MCL, keeping in mind that
treatment for radium does not differentiate between the different
isotopes. Since radium-228 is estimated to be eight times more
radiotoxic than radium-224, it appears that radium-224 may not be a
pressing public health concern compared to the co-occurring regulated
contaminant radium-228. The Agency plans to collect additional national
occurrence information for radium-224, which may involve coordination
with the USGS, and will evaluate whether future regulatory action or
guidance is necessary. Radium-224 occurrence data collection activities
are not as high a priority as addressing other radionuclide commitments
such as the review of the beta particle and photon radioactivity MCL.
For several reasons, a change in the gross alpha particle activity
holding time has been determined to be an inappropriate regulatory
solution. First, the uncertainty in the national occurrence data does
not allow EPA to determine the number of systems out of compliance with
the gross alpha particle activity standard due to radium-224 if a

[[Page 76718]]

48-72 hour holding time is required. Since this change may result in a
significant number of systems out of compliance with the current gross
alpha particle activity MCL, EPA would need to issue a proposed
amendment before making such a change. Such a proposal would require
national level occurrence data for radium-224 in drinking water. Since
EPA's next course of action is to collect such data to determine if a
proposal is needed, EPA believes that this course of action is the
appropriate one.
a. Summary of Major Comments on Radium-224
(1) The Use of a Short Gross Alpha Particle Activity Sample Holding
Time to Measure Radium-224: Several commenters stated that the use of a
short gross alpha sample holding time to measure radium-224 would raise
technical difficulties and would be costly. Several commenters stated
that there was not enough information to warrant a change to the gross
alpha holding time or to regulate radium-224 separately. EPA agrees
with this comment and, as stated in the Notice of Data Availability
(NODA; USEPA 2000e), will not change the gross alpha holding time or
regulate radium-224 separately in today's final rule. Some commenters
stated that it would not be appropriate to change the holding time or
to issue a separate standard in the final rule without a proposal. This
is in agreement with what the Agency stated in the NODA.
(2) The Need to Regulate Radium-224: One commenter suggested that
the radium-224 cancer mortality risk coefficient from Federal Guidance
Report-13 (FGR-13) warranted a health concern and warranted regulating
radium-224. While EPA agrees that radium-224 is a health concern, the
radium-224 cancer mortality unit risk is eight times less than the
radium-228 cancer mortality unit risk. In other words, it would take 40
pCi/L of radium-224 to present an equal cancer mortality risk as 5 pCi/
L of radium-228. Since the correlation between radium-224 and radium-
228 is approximately one-to-one (1:1) in the areas known to be of
concern, one would typically expect to find 5 pCi/L of radium-224
associated with 5 pCi/L of radium-228. Since radium-226 and radium-228
also significantly co-occur, EPA believes that in most situations in
which radium-224 occurs it would be present at levels lower than 5 pCi/
L for systems in compliance with the combined radium-226/-228 standard.
Table I-3 shows the predicted increase in risk for water systems in
areas in which radium-224 is known to co-occur with radium-228,
assuming a 1:1 correlation. This table shows that the presence of
radium-224 increases the over-all combined radium risk by 5%-13%,
depending on the relative contributions of radium-226 to radium-228 to
the MCL of 5 pCi/L. EPA believes that this situation indicates that
radium-224 may be of concern in some areas, but also believes that
collecting data to determine if radium-224 is of national concern is
the appropriate next step for determining if radium-224 should be
regulated separately.

Table 1-3.--Typical Increase in Combined Radium Risk Due to Presence of
Ra-224 for Water Systems With Combined Ra-226/-228 Levels of 5 pCi/L,
Assuming a 1:1 Correlation of Ra-224 and Ra-228
------------------------------------------------------------------------
Percent increase
in risk due to
Ra-226 (pCi/L) Ra-228 (pCi/L) Ra-224 (pCi/L) presence of Ra-
224
------------------------------------------------------------------------
5 0 0 0%
4 1 1 5%
3 2 2 8%
2 3 3 10%
1 4 4 12%
0 5 5 13%
------------------------------------------------------------------------

6. Entry Point Monitoring and the Standardized Monitoring Framework
The changes to the existing distribution system-based monitoring
scheme proposed in 1991 are promulgated in today's final rule. New
monitoring must be performed at entry points to the distribution
system, which is meant to ensure that all customers are protected by
the radionuclides NPDWRs. The 1976 monitoring scheme ensured that
``average customers'' were protected, but did not ensure that all
customers were served by water at or below the MCL for the various
radionuclides.
While EPA is finalizing a change to the point of compliance from a
representative distribution system sampling point to all points of
entry to the distribution system, EPA realizes that unless data
grandfathering is allowed, many systems will have to re-establish
monitoring baselines that have been established for many years. The
``monitoring baseline'' refers to the average contaminant level
analytical result that is used for determining the future monitoring
frequency. For this reason, EPA is allowing primacy entities (States,
Tribes, and other) the option of developing data grandfathering plans
that are suited to their individual situations (e.g., occurrence
patterns, water system configurations, and other factors) as a part of
their primacy packages. This situation will allow primacy entities
flexibility to grandfather historical data for determining future
monitoring frequencies, while allowing EPA oversight of the process to
ensure that the goal of having each entry point in compliance with the
MCLs is met. Since future monitoring will be conducted at each entry
point, this approach will ensure that compliance is achieved at every
entry point.
The new requirements for uranium and radium-228 will mean that
initial monitoring baselines for determining future monitoring
frequencies will need to be established. Only community water systems
that have gross alpha particle activity screening levels greater that
15 pCi/L will be required to monitor for uranium. Thus, many systems
will be able to use historical gross alpha data to determine future
monitoring frequency under the uranium standard. And, since the current
monitoring requirements for gross alpha particle activity already
require systems with gross alpha particle activity levels greater than
15 pCi/L to quantify uranium levels (to subtract out the uranium
contribution to the gross alpha particle activity), EPA expects that
many of these water systems will also be able to grandfather historical
uranium data. Given this situation, EPA does not expect uranium
monitoring requirements to be overly burdensome to community water
systems or drinking water programs.
Community water systems without historical radium-228 data
(expected to be those with gross alpha particle

[[Page 76719]]

activity levels less than 5 pCi/L and radium-226 levels less than 3
pCi/L) will need to establish an initial monitoring baseline to
determine future monitoring frequency. Four consecutive quarterly
samples will be required to establish this baseline. However, States
and Tribes may waive the last two quarterly samples and determine the
initial monitoring baseline on the first two samples if the results for
the first two samples are below the detection limit (1 pCi/L), which
would be considered a non-detect and would be reported as ``zero''
(this discussion assumes that radium-226 levels are also non-detects
and are reported as zero). Systems with non-detects for radium-228 and
radium-226 would have to monitor once every nine years after the
initial monitoring period. Other monitoring requirements are discussed
in section I.J.
7. Separate Monitoring for Radium-228 and Change to Systems Required To
Monitor for Beta Particle and Photon Radioactivity
Separate monitoring for radium-228, proposed in 1991, is
promulgated in today's rule. The need for separate monitoring of
radium-228 is supported by the occurrence studies supporting the 1991
proposal and new occurrence studies (USEPA 2000e and i), which indicate
that the 1976 radium-228 screens are not robust. Since the unit risks
for radium-228 are higher than for radium-226 (described in the NODA
and its Technical Support Document, USEPA 2000e and h), EPA believes
that separate monitoring for radium-228, as proposed in 1991, is
essential to enforcing the combined radium-226/-228 standard.
In addition, today's rule eliminates the previous requirement that
all surface water systems serving more than 100,000 persons must
monitor for beta particles and photon radioactivity. Beta particle and
photon radioactivity monitoring will be performed only by community
water systems designated by the State as ``vulnerable'' or
``contaminated''. In 1976, the Agency was concerned about nuclear
fallout contaminating surface water sources. The Agency anticipated
that large surface water systems (i.e. systems serving greater than
100,000 persons) would be vulnerable to becoming contaminated by
nuclear testing activities. Therefore, the radionuclides regulation
required all surface water systems serving more than 100,000 persons
and any other systems determined by the State to be vulnerable to
monitor for beta and photon emitters.
Since that time above-ground testing of nuclear weapons has been
banned, and sources of man-made radiation are not expected, thus, large
surface water systems are not automatically vulnerable to beta and
photon emitters. As a result, the Agency has reevaluated the 1975
approach, and in today's rule, as proposed in 1991, is removing the
requirement for all large surface water systems to monitor for beta and
photon emitters, unless they have been designated as vulnerable by the
State. The Agency believes that States are in the best position to
determine which systems are vulnerable to beta and photon emitters. The
EPA is also encouraging States to reevaluate a system's vulnerability
to beta photon emitters when conducting source water assessments and
provide immediate notification to those systems that have been deemed
vulnerable.
8. Future Actions Regarding the Regulation of Radionuclides at Non-
Transient Non-Community Water Systems
EPA will not regulate NTNC water systems with today's rule, but may
propose to do so in the future. As described in the NODA (USEPA 2000e),
EPA considered regulating non-transient non-community (NTNC) water
systems for today's final rule, as proposed in 1991. The NODA also
described EPA's analysis of the risks faced by customers of NTNC water
systems, potential risk reductions, and compliance costs. EPA stated
that several options were being considered for finalization: (1) Not
regulating NTNC water systems; (2) regulating all NTNC water systems
under the same requirements faced by CWSs; (3) regulating targeted NTNC
water systems, based on occurrence potential, typical lengths of
exposure, the age distribution of typical customers, and other factors;
(4) issuing guidance recommending that States require that targeted
NTNC systems monitor, and in some cases, mitigate to acceptable levels.
EPA's rationale for not regulating NTNC water systems at this time
is based upon consideration of several factors. EPA summarized the
results of a conservative Monte Carlo analysis of risks at NTNC water
systems in the NODA and discussed the analysis in more detail in its
Technical Support Document (USEPA 2000h). After evaluating the
available information and the various comments on the NODA, EPA does
not believe that exposure to radionuclides by consumers of water from
NTNC systems poses an unacceptable health risk. This conclusion is
based on consideration of the total pattern of exposure of individuals,
considering their consumption of both NTNC water and water from other
types of water systems. However, EPA's information for these
radionuclides is limited and will be the subject of additional future
analyses and reevaluation, together with any new data that can be obtained.
In the immediate future and in consultation with the National
Drinking Water Advisory Committee (NDWAC), EPA will further evaluate
various approaches to regulating NTNCs generally (including
radionuclides). This further analysis will involve examination of
additional data and information and will include further analysis of a
full range of possible options. In this evaluation, EPA will consider
risk analyses for adults and children, occurrence patterns, the
national distribution of NTNC water systems, and other factors. In
determining the appropriate action, EPA will consider the issue of
consistency between the various regulations for chronic contaminants
applicable to NTNC water systems, including future rules.
a. Summary of Major Comments on NTNCWSs and EPA Responses
Of the 70 commenters who responded to the April 21, 2000 NODA,
approximately 31 commented on the issue of NTNC water systems and the
options presented in the NODA. About 75 percent of these 31 commenters
oppose regulation of NTNC water systems. While several of the
commenters felt that EPA should only require targeted monitoring, many
commenters felt that monitoring of NTNC water systems should be left to
the discretion of the States. A few commenters felt that EPA should
treat NTNC water systems like CWSs and require regulation and some
commenters felt partial coverage of targeted NTNC water systems would
be appropriate.
Those opposed to the regulation of NTNC water systems felt the
cost/benefit and risk analyses presented in the NODA did not support a
requirement to regulate. Some of those opposed to regulating NTNC water
systems believe EPA needs to gather more information about the
occurrence of radionuclides, the amount and percentage of water
consumed, and the duration of exposure at NTNC water systems. Many
commenters felt that EPA should allow States the flexibility or
discretion to determine whether or not to regulate NTNC water systems
and leave it to the States to target specific NTNC water systems. Some
commenters

[[Page 76720]]

suggested that EPA issue guidance that recommends targeted NTNC water
systems monitor and meet the CWS MCLs. In addition, some commenters
stated that EPA should be consistent in all their rules when
considering whether or not to regulate NTNC water systems. EPA believes
that all of these comments have merit and that the regulation of
radionuclides at NTNC water systems deserves further evaluation along
with an analysis of additional data and information. If EPA proposes to
regulate NTNC water systems in the future, stakeholders will have
future opportunity to comment. Regarding State discretion, States may
at any time choose to regulate NTNC water systems, either under a
targeted rule or otherwise.

E. What Are the Health Effects That May Result From Exposure to
Radionuclides in Drinking Water?

Radioactive drinking water contaminants differ from one another in
ways that determine their harmfulness. Each radionuclide has a
particular half-life and emits characteristic forms of radiation (alpha
particles, beta particles, and/or photons). A radionuclide's half-life
and concentration determine its radioactivity, i.e., the number of
radioactive ``decay events'' that occur in a particular unit of time.
These factors, concentration, half-life, form of radioactive decay, and
radiation energy, all determine a particular radionuclide's potential
for impacting human health. For a discussion of half-life and the
different forms of radioactive decay, see Appendix I (``Fundamentals of
Radioactivity in Drinking Water'') to the Radionuclides NODA's
Technical Support Document (USEPA 2000h).
The potential for harmful health effects from exposure to
radioactive compounds results from the ability of ionizing radiation to
chemically change the molecules that make-up biological tissues (e.g.,
stomach, liver, lung) through a process called ``ionization.'' The
radiation (alpha and beta particles and photons) emitted by
radionuclides is called ``ionizing radiation'' because the radiation
has sufficient energy to strip electrons from nearby atoms as they
travel through a cell or other material. Ionization may result in
significant chemical changes to biologically important molecules. For
example, ionizing radiation can damage important molecules like DNA.
DNA is the elementary building block for genes and the chemical that
carries genetic information involved in many fundamental biological
processes. Damage to the DNA of an individual gene may cause the gene
to mutate, changing a cell's genetic code. Such mutation can lead to
cancer. Since ionizing radiation may damage genes, it can adversely
affect individuals directly exposed as well as their descendants. While
much of this cellular damage is repaired by the body, restoring proper
biological functions, the net result of an increase in exposure to
ionizing radiation is an increase in the risk of cancer or harmful
genetic mutations that may be passed on to future generations. (See,
EPA's fact sheets on ionizing radiation and associated health effects
at http://www.epa.gov/radiation/ionize.htm and in the record of this
final rulemaking; (USEPA 1998a and1998c)).
Alpha emitters and beta/photon emitters differ in the magnitude of
their biological effects. Alpha particles interact very strongly with
matter (e.g., human tissues), transferring their energy through these
interactions. Beta particles interact less strongly, which allows them
to travel further through tissue before being absorbed. The difference
of interest is in the concentration of tissue damage. Alpha particles
may damage many molecules over a short distance, while beta particles
may damage molecules spread out over a greater distance. The actual
number of potentially damaged molecules depends upon the energy of the
alpha particle or beta particle (which differs between individual alpha
emitters and beta emitters). Photon emissions may also interact with
tissues, but they interact over much longer distances (they can pass
through the body entirely). Exposure to any of these forms of radiation
increases the risk of cancer.
All people are chronically exposed to background levels of
radiation present in the environment. Many people also receive
additional chronic exposures, including exposure to radionuclides in
drinking water, and/or relatively small acute exposures, for example
from medical X-rays. For populations receiving such exposures, the
primary concern is that radiation could increase the risk of cancers or
harmful genetic effects.
The likelihood of developing cancer or genetic mutations from
short-term exposure to the concentrations of radionuclides found in
drinking water supplies is negligible. However, long-term exposures may
result in increased risks of genetic effects and other effects such as
cancer, precancerous lesions, benign tumors, and congenital defects.
For example, an individual that is exposed to relatively high levels of
radium-228 (e.g., 20 pCi/L) in drinking water over the course of a
lifetime is projected to have a significantly increased chance of
developing fatal cancer (roughly a one in one thousand increased risk
if exposed to radium-228 at 20 pCi/L over a lifetime of 70 years).
The probability of a radiation-caused cancer or genetic effect is
related to the total amount of radiation accumulated by an individual.
Based on current scientific models, it is assumed that any exposure to
radiation may be harmful (or may increase the risk of cancer); however,
at very low exposures (e.g., drinking water exposures below the MCL),
the estimated increases in risk are very small and uncertain. For this
reason, cancer rates in populations receiving very low doses of
radiation may not show increases over the rates for unexposed populations.
For information on effects at high levels of exposure, scientists
largely depend on epidemiological data on survivors of the Japanese
atomic bomb explosions and on people receiving large doses of radiation
for medical purposes. These data demonstrate a higher incidence of
cancer among exposed individuals and a greater probability of cancer as
the exposure increases. In the absence of more direct information, that
data is also used to estimate what the effects could be at lower
exposures. Where questions arise, scientists extrapolate from
information obtained from cellular and molecular studies, but these
extrapolations are acknowledged to be only estimates. Professionals in
the radiation protection field prudently assume that the chance of a
fatal cancer from radiation exposure increases in proportion to the
magnitude of the exposure.
In the case of uranium in drinking water, we must consider not only
carcinogenic health effects but also damage to the kidneys that may
result from ingestion. When uranium radioactively decays in the body,
it results in increased cancer risks. However, natural uranium isotopes
have long half-lives, which means that uranium tends to persist in the
body until it is excreted or stored in tissue. As discussed in detail
in the Notice of Data Availability (USEPA 2000e), its Technical Support
Document (USEPA 2000h), and the Toxicological Review of Uranium (USEPA
2000b) this persistent uranium may result in kidney toxicity. See
section I.D.2 for a brief summary of kidney (renal) function and
uranium toxicity.
1. Major Comments
Most comments on Health Effects related to three areas of risk
estimation: (1) The use of a linear, non-threshold model, (2) not
finding a threshold for

[[Page 76721]]

radium, and (3) not promoting claimed beneficial effects of ionizing
radiation.
a. Linear Non-threshold Model: Some commenters suggested that the
Agency abandon the linear nonthreshold (LNT) model it employs to
estimate radiation induced carcinogenesis. They suggest a new paradigm
should be used.
The Agency disagrees and believes its position is based on weight
of evidence and support from national and international groups of
experts interested in radiation protection. EPA classifies all
radionuclides as Group A (known human) carcinogens. This classification
is based on the considerable weight of epidemiological evidence that
exposure to high doses of ionizing radiation causes cancer in humans
and on the fact that all radionuclides emit ionizing radiation.
Radiation has been shown to induce unique DNA damage, mutations, and
transformation of cells in culture. The monoclonal nature of cancers is
evidence that a single ``wild'' cell can give rise to a cancer. For
alpha particles, it has been shown experimentally that a single alpha
passing through a cell is sufficient to induce a mutational event;
there are strong theoretical reasons to expect that the same is true
for low energy transfer (LET) radiation such as gamma rays. Since a
single particle traversal of a cell is the minimum event for radiation
exposure, a prudent assumption is that there is no threshold for
radiation induced mutations.
To estimate radiogenic cancer risks and to regulate low-dose
radiation exposures from continuous intakes of radionuclides in
environmental media, EPA uses a linear, non-threshold (LNT) dose-
response model. The LNT model permits direct extrapolation of low-dose
cancer risks from high-dose exposures--allowing for adjustments, as
needed, for differences in radiation quality, dose rate, and exposed
populations, including such factors as age at exposure, time since
exposure, baseline cancer rates, and gender and assumes that there is
no threshold for effects; i.e., it is assumed that exposure to any
amount of radioactivity has a finite potential to induce cancers in
humans. As noted above, support for the LNT model comes in part from
the linear dose-response relationships observed for most types of
cancers in the intermediate- to high-dose range for atomic bomb
survivors, and from results of molecular and cellular studies. Several
such studies have shown that a single radiation track traversing a cell
nucleus can cause unrepaired or misrepaired DNA lesions and chromosomal
aberrations. Other studies have shown that DNA lesions and chromosomal
aberrations can lead to cancer. From these studies, it is assumed that
the probability of DNA damage and carcinogenesis is linearly
proportional to the dose.
EPA's application of the LNT model to estimate and regulate cancer
risks from environmental exposures to radionuclides is entirely
consistent with all past and current observations and recommendations
of the International Commission on Radiological Protection (ICRP), the
National Council on Radiation Protection and Measurements (NCRP), the
National Academy of Sciences Committee on the Biological Effects of
Ionizing Radiation (BEIR), and the United Nations Scientific Committee
on the Effect of Atomic Radiation (UNSCEAR), and the National Radiation
Protection Board (NRBP). Citing the recommendations of these national
and international advisory bodies, the U.S. Department of Energy, the
U.S. Nuclear Regulatory Commission, and other Federal and State
agencies with regulatory authority over radioactive materials also
apply the LNT model as the basis for setting regulations and guidelines
for radiation protection. However, to address these limitations and the
uncertainties associated with this model and improve its radiation risk
assessments, EPA is actively supporting national and international
studies of radiation dosimetry and dose reconstruction, radionuclide
biokinetics, quantitative techniques for uncertainty analyses, and
long-term follow-up epidemiological studies of populations exposed
chronically to low-dose radiation. The Agency also continues to review
its policies and positions as new reports and data are published so
that the best science is applied.
b. Radium Carcinogenicity Threshold: Some commenters have suggested
that there is a threshold for radium carcinogenicity. They generally
base this conclusion on the ``Radium Dial Painter'' studies.
The Agency disagrees. While the ``Radium Dial Painter'' studies are
interesting, they are of limited value for the estimation of risk.
First, no one knows the quantity of radium ingested in those studies,
so dose estimates are speculative. The intake estimates are based on
the body burden the first time the subjects were measured and back-
calculated with biokinetics modeling. Moreover, the quantities of
radium ingested by the subjects was great enough to cause extensive
skeletal pathology and interfere with normal bone metabolism. In
addition to problems of radium dosimetry, the high mortality in some
groups, and the small numbers of subjects in all exposure groups, would
impair use of the data to develop dose response relationships.
Only a small fraction of persons known to have been exposed to
radium have been located and their radium content at that time
measured. Of 6,675 subjects identified above as being in the data base
and as having been exposed to radium, 2,383 have been measured to
determine their radium-226 burden. (21 of the 85 osteosarcomas occurred
in subjects who had never been measured for radium burden.) Since the
radium intake in dial painters is unknown, body burden is known only
from the date of first radioassay (usually many years after the radium
intake), and metabolism is estimated from other sources, estimates of
the radiation dose must be based on a series of poorly verified
assumptions. In spite of these inherent problems in the data set,
efforts have been made to use the radium dial workers, or some subset
of them, to establish a ``practical threshold'' for radium or other
internal emitter exposure.
The ``practical threshold'' concept is derived from studies of
chemical carcinogenesis which include dose levels causing extensive
life shortening. Plots of the mean age at tumor onset vs dose indicates
an increase in tumor latency with decreasing dose. Extrapolation of
these curves to environmental dose levels has led some investigators to
conclude at these dose levels tumor latency would exceed the human life
span. This ``practical threshold'' is as an argument for a threshold
and against LNT models. The ``practical threshold'' model has been
examined and rejected by experts at the International Agency for
Research on Cancer (IARC). The IARC warned in their discussion
regarding mean tumor latency or mean age at tumor onset that ``care
must be taken not to extrapolate the observed tendency for the mean age
at onset to increase with decreasing dose below the dose range in which
most animals get cancer. Failure to observe this restriction has led to
the unjustified speculation that progressively lower and lower human
doses of environmental contaminants will produce cancers only at age
200 or 300 years; for refutation, see Peto (1978).''
Even if there were no problems with intake, dose, metabolism,
extensive pathology, etc., as mentioned above, the radium dial studies
would be uninformative on the subject of the dose response relationship
at environmental exposure levels. The number of subjects and their
distribution in dose categories is too small. The number of subjects

[[Page 76722]]

needed to show a given risk increases as the square of the decrease in
dose. For example, if 10 subjects are required to show an radiogenic
risk at dose level x, 250 would be needed to show the same risk at dose
level x/5, and 1000 at dose level x/10. There just are not enough
subjects at lower dose levels to show the risk, giving the illusion of
a threshold.
The claims regarding a possible ``practical threshold'' addressed
above are based solely on the bone cancer data. However, bone cancer
constitutes only a fraction of the estimated risk from ingested radium.
Radium-226 has also been found to induce epithelial cancers in sinuses
in the head (due to radon-222 released into the sinus air spaces from
the decay of radium-226 in bone). The data in the dial painter study is
inadequate to develop a dose response relationship for sinus cancers,
however the number of epithelial cancers expected in the dial painters
is about the same as the number of bone cancers. The number of bone
cancers in the Agency's radium-226 risk model is doubled to get an
estimate of combined bone and sinus cancers. In addition to bone
cancer, patients treated with radium-224 were found to have significant
increases in breast cancer, soft tissue sarcomas, liver cancer, thyroid
cancer, cancers of urinary organs, and leukemia. Given our
understanding of radium metabolism and the effects of alpha
irradiation, it is expected that ingestion of any of the radium
isotopes will increase the risks for various types of cancer other than
bone. EPA's risk estimates include all these potential sites.
c. ``Beneficial Effects'' of Radiation: One commenter suggests
there are beneficial effects of radiation, ``Hormesis'' (small doses of
radiation are good for you) and ``Adaptive Response'' (relatively small
doses of radiation protect against large doses of radiation).
The Agency finds that, based on available scientific evidence,
these phenomena are not relevant to environmental radiation protection.
Neither has been shown to occur at environmental dose levels. Neither
has been shown to influence the dose response for induction of
radiation induced cancer. Hormesis has not been demonstrated in normal
healthy active populations of mammals, much less in humans. Adaptive
response may have some application in radiotherapy (very high radiation
doses), but it is not relevant to environmental exposure levels.
Hormesis is a non-specific phenomenon. Biological, chemical, or
physical agents may stimulate hormesis; thus, cold, physical stress,
toxic chemicals, antibiotics, as well as ionizing radiation, can be
hormetins. Hormesis originally was used to describe a stimulatory
effect, which was not inherently good or bad. Recent usage of the term
``Radiation Hormesis'' implies the discussion relates to beneficial
effects. It should not, however, imply absence of radiation
carcinogenesis.
The ``adaptive response'' is also a nonspecific response to stress,
which has been observed at the cellular level. An ``adaptive response''
is observed experimentally when a ``conditioning'' exposure is given,
followed at some later time by a ``challenge'' exposure, and the
response in the ``conditioned'' organism or cell culture is less than
in controls; that is, the conditioning exposure was ``protective''
against the challenge. In typical studies where cells in culture are
given a conditioning dose of radiation in the range of 0.2 to 20 rad (2
to 200 milliGray or mGy), a dose of 100 to 200 rad (1000 to 2000 mGy)
given later causes only about 50% as great an effect as that observed
in controls with no conditioning exposure. However several points are
noteworthy: not all cells respond, effects may be different for cells
at different stages in the cell cycle, not all conditioning doses give
the same response (sometimes instead of protection there is synergism
between doses), the ``adaptive'' effects are transient, and the timing
of the challenge dose may be critical to response. Given these
limitations, EPA does not believe it is appropriate at this time to
consider such an adaptive response in its assessment of the risks from
environmental levels of radiation.

F. Does This Regulation Apply to My Water System?

The NPDWRs for combined radium-226 and radium-228, gross alpha
particle radioactivity, beta particle and photon radioactivity, and
uranium apply to all community water systems.

G. What Are the Final Drinking Water Regulatory Standards for
Radionuclides (Maximum Contaminant Level Goals and Maximum Contaminant
Levels)?

The maximum contaminant level goals (non-enforceable health-based
target, MCLGs) and maximum contaminant levels (enforceable regulatory
limits, MCLs) are listed in table I-4. For the reasons already
described, EPA is retaining the existing MCLs for combined radium-226
and radium-228, gross alpha, and beta particle and photon
radioactivity. EPA is finalizing an MCL of 30 g/L for uranium,
based on kidney toxicity and cancer risk endpoints. The final MCLGs are
zero for all radionuclides, based on the no-threshold cancer risk model
for ionizing radiation.

Table I-4.--MCLGs and MCLs for Radionuclides in Drinking Water (Other
Than Radon)
------------------------------------------------------------------------
Contaminant MCLG (pCi/L) MCL
------------------------------------------------------------------------
Combined Radium-226 and Radium- Zero.............. 5 pCi/L.
228.
Gross Alpha (Excluding radon Zero.............. 15 pCi/L.
and uranium).
Beta Particle and Photon Zero.............. 4 mrem/year.
Radioactivity.
Uranium........................ Zero.............. 30 g/L.
------------------------------------------------------------------------

H. What Are the Best Available Technologies (BATs) for Removing
Radionuclides From Drinking Water?

Under the SDWA, EPA must specify the best available technology
(BAT) for each MCL that is set. PWSs that are unable to achieve an MCL
may be granted a variance if they use the BAT and meet other
requirements (see section I.M for a discussion of variances and
exemptions). Table I-5 lists the best available technologies (BATs) for
complying with the radionuclides MCLs.

Table I-5.--Best Available Technologies (BATs) for Radionuclides in
Drinking Water
------------------------------------------------------------------------
Contaminant BAT
------------------------------------------------------------------------
Combined radium-226 and radium-228..... Ion Exchange, Lime Softening,
Reverse Osmosis.

[[Page 76723]]

Gross alpha (excluding radon and Reverse Osmosis.
uranium).
Beta particle and photon radioactivity. Ion Exchange and Reverse
Osmosis.
Uranium................................ Ion Exchange, Lime Softening;
Reverse Osmosis, Enhanced
Coagulation/Filtration.
------------------------------------------------------------------------

In addition to BATs, the SDWA, as amended in 1996, requires EPA to
list small system compliance technologies (the requirements are
described in section I.M). EPA published a list of small systems
compliance technologies for the existing radionuclide MCLs in 1998 (63
FR 42032) and issued a guidance document on their use (USEPA 1998f).
EPA took comment on small system compliance technologies for uranium in
the NODA (USEPA 2000e; 65 FR 21576). Table I-6 is a compilation of all
of the small systems compliance technologies for radionuclides,
including limitations, required operator skill, raw water quality
ranges, and other considerations. Table I-7 shows the small systems
compliance technologies listed for: combined radium-226 and radium-228,
gross alpha particle radioactivity, beta particle and photon
radioactivity, and uranium.

Table I-6.--List of Small Systems Compliance Technologies for Radionuclides and Limitations to Use
----------------------------------------------------------------------------------------------------------------
Limitations (see Operator skill level Raw water quality range &
Unit technologies footnotes) required \1\ considerations \1\
----------------------------------------------------------------------------------------------------------------
1. Ion Exchange (IE)............... (a) Intermediate............... All ground waters.
2. Point of Use (POU \2\) IE....... (b) Basic...................... All ground waters.
3. Reverse Osmosis (RO)............ (c) Advanced................... Surface waters usually
require pre-filtration.
4. POU \2\ RO...................... (b) Basic...................... Surface waters usually
require pre-filtration.
5. Lime Softening.................. (d) Advanced................... All waters.
6. Green Sand Filtration........... (e) Basic...................... ..........................
7. Co-precipitation with Barium (f) Intermediate to Advanced... Ground waters with
Sulfate. suitable water quality.
8. Electrodialysis/Electrodialysis .................. Basic to Intermediate...... All ground waters.
Reversal.
9. Pre-formed Hydrous Manganese (g) Intermediate............... All ground waters.
Oxide Filtration.
10. Activated alumina.............. (a), (h) Advanced................... All ground waters;
competing anion
concentrations may affect
regeneration frequency.
11. Enhanced coagulation/filtration (i) Advanced................... Can treat a wide range of
water qualities.
----------------------------------------------------------------------------------------------------------------
\1\ 1 National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities.
National Academy Press. Washington, DC 1997.
\2\ 2A POU, or ``point-of-use'' technology is a treatment device installed at a single tap used for the purpose
of reducing contaminants in drinking water at that one tap. POU devices are typically installed at the kitchen
tap. See the April 21, 2000 NODA for more details.
Limitations Footnotes to Table I-6: Technologies for Radionuclides
a The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be
carefully considered before choosing this technology.
b When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring must
be provided by water utility to ensure proper performance.
c Reject water disposal options should be carefully considered before choosing this technology. See other RO
limitations described in the SWTR Compliance Technologies Table.
d The combination of variable source water quality and the complexity of the water chemistry involved may make
this technology too complex for small surface water systems.
e Removal efficiencies can vary depending on water quality.
f This technology may be very limited in application to small systems. Since the process requires static mixing,
detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate levels that
already have a suitable filtration treatment train in place.
g This technology is most applicable to small systems that already have filtration in place.
h Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems
without an adequately trained operator.
i Assumes modification to a coagulation/filtration process already in place.

Table I-7.--Compliance Technologies by System Size Category for Radionuclide NPDWRs
----------------------------------------------------------------------------------------------------------------
Compliance technologies \1\ for system
size categories (population served)
Contaminant ------------------------------------------ 3,300-10,000
25-500 501-3,300
----------------------------------------------------------------------------------------------------------------
Combined radium-226 and radium- 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 8, 9
228. 7, 8, 9. 7, 8, 9.
Gross alpha particle activity... 3, 4............... 3, 4............... 3, 4
Beta particle activity and phton 1, 2, 3, 4......... 1, 2, 3, 4......... 1, 2, 3, 4
activity.

[[Page 76724]]

Uranium......................... 1, 2, 4, 10, 11.... 1, 2, 3, 4, 5, 10, 1, 2, 3, 4, 5, 10, 11
11.
----------------------------------------------------------------------------------------------------------------
Note: (1) Numbers correspond to those technologies found listed in the table I-6 above.

I. What Analytical Methods Are for Compliance Monitoring of
Radionuclides?

The approved methods for compliance monitoring of radionuclides are
listed in Sec. 141.25. These methods are shown in Table I-8. A large
portion of the approved methods for radionuclides were added after the
1991 proposed rule (56 FR 33050). There, the Agency proposed to approve
fifty-six methods for the measurement of radionuclides in drinking
water (excluding radon). Fifty-four of the fifty-six were actually
promulgated in the March 5, 1997 final methods rule (62 FR 10168). In
addition to these fifty-four, EPA also promulgated 12 radiochemical
methods in the March 5, 1997 final methods rule, which were submitted
by commenters after the 1991 proposed rule.
In the March 5, 1997 final methods rule for radionuclides (62 FR
10168), the Agency approved several methods for the analysis of
uranium. Specific analysis for uranium can be performed by
radiochemical methods, alpha spectrometry, fluorometric (mass), or
laser phosphorimetry (mass) (see Table I-8). The radio-chemical method
separates and concentrates uranium from potentially-interfering
radionuclides and non-radioactive sample constituents. The resulting
concentrate, depending on the method, can then be counted by gas flow
proportional counting, alpha scintillation, or alpha spectrometry.
Results from proportional counting or alpha scintillation counting
accurately determine the alpha emission rate from total uranium in the
sample; however, the uranium isotope ratio (uranium-234/uranium-238)
cannot be determined and the uranium mass cannot be estimated unless an
empirical conversion factor is applied to the measured count rate. The
use of alpha spectrometry allows for the determination of individual
isotopes of uranium and the accurate calculation of the mass of
uranium-238 present in the sample. Additionally, the concentration of
uranium-234 can be accurately measured, if necessary to assess the
radiotoxicity of this isotope.
Both the fluorometric and the laser phosphorimetry methods measure
the mass of uranium-238 present in the sample; a conversion factor must
be used to convert the mass measurement to an approximate radioactivity
concentration in picoCuries. The computed radioactivity is only
approximate because the ratio of uranium isotopes must be assumed. The
use of mass-type methods is acceptable provided a conversion factor of
0.67 pCi/g is used to convert the fluorometric or laser
phosphorimetry uranium-238 mass result from micrograms to picoCuries.
This conversion factor is conservative and is based on a 1:1 ratio of
uranium-234 to uranium-238 in uranium-bearing minerals. The scientific
literature indicates that the activity ratio varies in ground water
from region to region (typically from 0.67 to 1.5 pCi/g).
EPA recognizes that the mass conversion factor is conservative in
that the calculated uranium alpha emission rate based on the mass
measurement may be biased low (i.e., underestimated). The use of this
conversion factor may result in a larger net gross alpha (gross alpha
less the calculated uranium gross alpha contribution), which may
require additional testing to resolve. Conversely, the calculated mass
of uranium based on gross alpha could be biased high and result in an
overestimation, which may require additional testing to resolve. Both
situations are protective in that the bias requires additional testing
to resolve when the uranium concentration in a sample is near the
proposed MCL regardless of which method is used to measure the uranium.
1. Major Comments
a. Request for ICP-MS Method for Uranium: In response to the NODA,
several commenters asked EPA to consider the approval of an Inductively
Coupled Plasma Mass Spectrometry (ICP-MS) method for uranium analysis
(a mass method). Many commenters stated that the ICP-MS method (i.e.,
EPA 200.8 or SM 3125) is more cost-effective, less labor-intensive and
offers greater sensitivity than some of the currently approved methods
for uranium analysis. EPA is currently reviewing the ICP-MS method for
uranium and will publish a proposal and a final in a future rulemaking.
b. Detection Limit for Uranium: In 1976, the NPDWRs defined the
``detection limit'' (DL) as the ``concentration which can be counted
with a precision of plus or minus 100 percent at the 95 percent
confidence level (1.96 , where is the standard
deviation of the net counting rate of the sample).'' The detection
limits for gross alpha, radium-226, radium-228, gross beta and other
radionuclides are listed at Sec. 141.25 and reproduced in Table I-9. In
the NODA, EPA stated that it would maintain the use of detection limits
as the required measures of sensitivity for radiochemical analysis,
instead of using the method detection limit (MDL), the practical
quantitation level (PQL) and acceptance limits, as was proposed in
1991. Although no comments were submitted about EPA's decision to
maintain the use of the detection limits listed in Sec. 141.25, several
commenters submitted comments about the appropriate measure of
sensitivity for uranium.
Since uranium was not previously regulated, no detection limit is
listed in the CFR and none was proposed in 1991. In 1991, the Agency
only proposed a PQL (5 pCi/L) and an acceptance limit (30%)
for uranium. Because the NODA was not the appropriate mechanism to
propose a detection limit for uranium, the Agency stated that it ``may
have to adopt the PQL for uranium until a detection limit is
proposed.'' Several commenters disagreed with the use of a PQL and
acceptance limits for uranium. They felt that EPA should be consistent
with other regulated radionuclides and set a detection limit for
uranium as the required measure of sensitivity. The Agency agrees with
the commenters and will propose a detection limit for uranium in a
future rulemaking before the compliance date of this rule to be
consistent with the sensitivity measures used for other radionuclides.

[[Page 76725]]

Table I-8.--Analytical Methods Approved by EPA for Radionuclide Monitoring (Sec. 141.25)
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Reference (method or page number)
Contaminant Methodology ----------------------------------------------------------------------------------------------------------------------
EPA \1\ EPA \2\ EPA \3\ EPA \4\ SM \5\ ASTM \6\ USGS \7\ DOE \8\ Other
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Naturally occurring:
Gross alpha \11\ and beta... Evaporation........ 900.0 p 1 00-01 p 1 302, 7110 B ............ R-1120-76 ............ ...........
Gross alpha \11\............ Co-precipitation... ....... ....... 00-02 ........ 7110 C ............ ............ ............ ...........
Radium 226.................. Radon emanation.... 903.1 p 16 Ra-04 p 19 7500-Ra C D 3454-91 R-1141-76 Ra-05 N.Y. \9\
Radiochemical...... 903.0 p 13 Ra-03 ........ 304, 305, 7500-Ra B D 2460-90 R-1140-76 ............ ...........
Radium 228.................. Radiochemical...... 904.0 p 24 Ra-05 p 19 304, 7500-Ra D ............ R-1142-76 ............ N.Y. \9\
N.J. \10\
Uranium \12\................ Radiochemical...... 908.0 ....... ........ ........ 7500-U B ............ ............. ............ ...........
Fluorometric....... 908.1 ....... ........ ........ 7500-U C (17th Ed.) D 2907-91 R-1180-76 U-04 ...........
R-1181-76
Alpha spectrometry. ....... ....... 00-07 p 33 7500-U C (18th or 19th D 3972-90 R-1182-76 U-02 ...........
Ed.)
Laser ....... ....... ........ ........ ....................... D 5174-91 ............ ........... ...........
phosphorimetry.
Man-made:
Radioactive cesium.......... Radiochemical...... 901.0 p 4 ........ ........ 7500-Cs B D 2459-72 R-1111-76 ............ ...........
Gamma ray 901.1 ....... ........ p 92 7120 D 3649-91 R-1110-76 4.5.2.3 ...........
spectrometry.
Radioactive iodine.......... Radiochemical...... 902.0 p 6 ........ ........ 7500-1 B ............ ............ ............
p 9 7500-1 C D 3649-91
7500-1 D
Gamma ray 901.1 ....... ........ p 92 7120 (19th Ed.) D 4785-88 ................ 4.5.2.3 ...........
spectrometry.
Radioactive Strontium 89, 90 Radiochemical...... 905.0 p 29 Sr-4 p. 65 303, 7500-Sr B ............. R-1160-76 Sr-01 ...........
Sr-02
Tritium..................... Liquid 906.0 p 34 H-2 p. 87 306,7500-3H B D 4107-91 R-1171-76 ............ ...........
scintillation.
Gamma emitters.............. Gamma ray 901.1 ....... ........ p 92 7120 (19th Ed.) D 3649-91 R-1110-76 4.5.2.3 ...........
spectrometry. 902.0 7500-Cs B D 4785-88
901.0 7500-I B
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ``Prescribed Procedures for Measurement of Radioactivity in Drinking Water,'' EPA 600/4-80-032 , August 1980. Available at U.S. Department of Commerce, National
Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161 (Telephone 800-553-6847), PB 80-224744.
\2\ ``Interim Radiochemical Methodology for Drinking Water,'' EPA 600/4-75-008 (revised), March 1976. Available at NTIS, ibid. PB 253258.
\3\ ``Radiochemistry Procedures Manual'', EPA 520/5-84-006, December 1987. Available at NTIS, ibid. PB 84-215581.
\4\ ``Radiochemical Analytical Procedures for Analysis of Environmental Samples,'' U.S. Department of Energy, March 1979. Available at NTIS, ibid. EMSL LV 053917.
\5\ Standard Methods for the Examination of Water and Wastewater, 13th, 17th, 18th, 19th Editions, 1971, 1989, 1992, 1995. Available at American Public Health Association,
1015 Fifteenth Street N.W., Washington, D.C. 20005. Methods 302, 303, 304, 305 and 306 are only in the 13th edition. Methods 7110B, 7110 C, 7500-Ra B, 7500-Ra C, 7500-Ra D,
7500-U B, 7500-Cs B, 7500-I B, 750-9I C, 7500-D, 7500-Sr B, 7500-3H B are in the 17th, 18th and 19th editions. Method 7500-U C Fluorometric Uranium is only in the 17th
Edition, and 7500-U C Alpha spectrometry is only in the 18th and 19th editions. Method 7120 is only in the 19th edition. Methods 302, 303, 304, 305 and 306 are only in the
13th edition.
\6\ Annual Book of ASTM Standards, Vol. 11.02, 1994; American Society for Testing and Materials; any year containing the cited version of the method may be used. Copies
may be obtained from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
\7\ ``Methods for Determination of Radioactive Substances in Water and Fluvial Sediments,'' Chapter A5 in Book 5 of Techniques of Water-Resources Investigations of the
United States Geological Survey, 1977. Available at U.S. Geological Survey Information Services, Box 25286, Federal Center, Denver, CO 80225-0425.
\8\ ``EML Procedures Manual'', 27th Edition, Volume 1, 1990. Available at the Environmental Measurements Laboratory, U.S. Department of Energy (DOE), 376 Hudson Street,
New York, NY 10014- 3621.
\9\ ``Determination of Ra-226 and Ra-228 (Ra-02),'' January 1980; Revised June 1982. Available at Radiological Sciences Institute Center for Laboratories and Research,
New York State Department of Health, Empire State Plaza, Albany, NY 12201.
\10\ ``Determination of Radium 228 in Drinking Water,'' August 1980. Available at State of New Jersey, Department of Environmental Protection, Division of Environmental
Quality, Bureau of Radiation and Inorganic Analytical Services, 9 Ewing Street, Trenton, NJ 08625.
\11\ Natural uranium and thorium-230 are approved as gross alpha-particle activity calibration standards for the gross alpha co-precipitation and evaporation methods;
americium-241 is approved for use with the gross alpha co-precipitation methods.
\12\ If uranium (U) is determined by mass-type methods (i.e., fluorometric or laser phosphorimetry), a 0.67 pCi/g uranium conversion factor must be used. This conversion
factor is conservative and is based on the 1:1 activity ratio of U-234 to U-238 that is characteristic of naturally-occurring uranium in rock.

Table I-9.--Required Regulatory Detection Limits for the Various
Radiochemical Contaminants (Sec. 141.25)
------------------------------------------------------------------------
Contaminant Detection Limit (pCi/L)
------------------------------------------------------------------------
Gross Alpha............................... 3
Gross Beta................................ 4
Radium-226................................ 1
Radium-228................................ 1
Cesium-134................................ 10
Strontium-89.............................. 10
Strontium-90.............................. 2
Iodine-131................................ 1
Tritium................................... 1,000
Other Radionuclides and Photon/Gamma \1/10\th of the rule.
Emitters.
------------------------------------------------------------------------

J. Where and How Often Must a Water System Test for Radionuclides?

1. Monitoring Frequency for Gross Alpha, Radium 226, Radium 228, and
Uranium
The monitoring scheme being finalized today provides for more
frequent, but less sample-intensive (on a per compliance site basis),
monitoring for systems with a demonstrated inherent vulnerability and
reduced monitoring for systems with low contaminant levels, which will
apply to most systems. Instead of the current monitoring framework for
radionuclides of four samples every four years for results above 50% of
the MCL and one sample every 4 years for those at or below 50% (at
State discretion), the revised rule calls for one sample every three
years for compliant systems with average contaminant levels above 50%
of the MCL but at or below the MCL, one sample every 6 years for
systems with levels above the detection limit and at or below 50% of
the MCL, and every 9 years for systems with levels below the detection
limit.
2. Monitoring Frequency for Beta Particle and Photon Radioactivity
Beta particle and photon radioactivity monitoring will be performed
only by community water systems designated by the State as
``vulnerable'' or ``contaminated''. A community water systems (both
surface and ground water) designated by the State as vulnerable must
collect quarterly samples for beta emitters and annual samples for
tritium and strontium-90 at each entry point to the distribution
system, beginning within one quarter after being notified by the State.
Systems already designated by the State must continue to sample until
the State reviews and either reaffirms or removes the designation. If
the gross beta particle activity minus the naturally occurring
potassium-40 beta particle activity at a sampling point has a running
annual average less than or equal to 50 pCi/L (screening level), the
system may reduce the frequency of monitoring at that sampling point to
once every 3 years.
Community water systems (both surface and ground water) designated
by the State as utilizing waters contaminated by effluents from nuclear
facilities must collect quarterly samples for beta emitters and iodine-
131 and annual samples for tritium and strontium-90 at each entry point
to the distribution system, beginning within one quarter after being
notified by the State. Systems already designated by the State as
systems using waters contaminated by effluents from nuclear facilities
must continue to sample until the State reviews and either reaffirms or
removes the designation. If the gross

[[Page 76726]]

beta particle activity beta minus the naturally occurring potassium-40
beta particle activity at a sampling point has a running annual average
less than or equal to 15 pCi/L (screening level), the system may reduce
the frequency of monitoring at that sampling point to every 3 years.
For CWS in the vicinity of a nuclear facility, the State may allow
the CWS to utilize environmental surveillance data collected by the
nuclear facility in lieu of monitoring at the system's entry point(s),
where the State determines if such data is applicable to a particular
water system. Community water systems designated by the State to
monitor for beta particle and photon radioactivity can not apply to the
State for a waiver from the monitoring frequencies.
Several USGS studies, including the study entitled Gross-beta
Activity in Ground Water: Natural Sources and Artifacts of Sampling and
Laboratory Analysis, have found that Potassium-40 and Radium-228 appear
to be the primary sources of beta activity in ground water. EPA
recognizes that naturally occurring potassium could trigger many
systems into conducting expensive beta speciation analysis due to
exceedance of the screening level. Therefore, as noted above, naturally
occurring Potassium-40 analyzed from the same or equivalent sample used
for the gross beta analysis may be subtracted from the total gross beta
activity to determine if the screening level is exceeded. The
potassium-40 beta particle activity must be calculated by multiplying
elemental potassium concentrations (in mg/L) by a factor of 0.82. If
the gross beta particle activity minus the naturally occurring
potassium-40 beta particle activity exceeds the screening level, an
analysis of the sample must be performed to identify the major
radioactive constituents present in the sample and the appropriate
doses must be calculated and summed to determine compliance with
Sec. 141.66(d). Doses must also be calculated and combined for measured
levels of tritium and strontium to determine compliance.
The regulatory language in Sec. 141.26(b)(6) of today's rule
requires systems to monitor monthly at sampling points which exceed the
maximum contaminant levels in Sec. 141.66(d) beginning in the next
month after the exceedance occurred. There are many circumstances that
may arise from this requirement such as collecting and obtaining the
results in two separate months, however, the EPA intended this to
require all systems to collect the initial monthly sample no later than
30 days following the collection date of the initial MCL exceedance.
The EPA believes that States have evaluated the vulnerability of
systems to potential beta emitting sources under the existing rule.
Therefore, States should use the existing vulnerability assessments to
notify systems of their status and monitoring requirements if they have
not provided that notification previously. The EPA is also encouraging
States to reevaluate a systems vulnerability to beta photon emitting
sources when conducting a systems source water assessment and provide
immediate notification to those systems that have been deemed vulnerable.
3. Sampling Points and Data Grandfathering
Because the current radionuclide NPDWRs have been in effect for
almost 25 years, States have much historical distribution system data
for the regulated radionuclides at most community water systems and
have data regarding occurrence patterns at various scales. The
monitoring scheme is an attempt to balance two opposing goals: first,
to ensure that every entry point is in compliance, and second, to allow
States and drinking water systems to make maximal use of the existing
distribution system historical data.
To meet the first goal, today's final rule requires that all new
monitoring be at the entry point to the distribution system. This will
ensure that all entry points are in compliance with the MCLs from now
on. But, rather than narrowly prescribing specific criteria for
grandfathering existing distribution system data, today's rule provides
flexibility to States to devise a grandfathering plan applicable to
their own circumstances. In particular, States may devise a plan for
determining which systems will need to analyze new samples from each
entry point to establish initial monitoring baselines for the currently
regulated radionuclides and which can rely on the existing distribution
system data for the same purpose (including existing uranium data). EPA
had considered more prescriptive options, such as allowing
grandfathering for systems with fewer than three entry points, systems
serving fewer than 3,300 persons, systems drawing from aquifers of
certain characteristics, etc. However, the many competing variables
present at the local level make generalizations impractical at the
national level. Since the grandfathering plans will be a part of the
primacy packages approved by the EPA Regions, EPA will have oversight
over these plans. EPA expects that the plans would allow grandfathering
only for situations in which it is to be expected that every entry
point is in compliance with the MCLs. For example, if a system with
five entry points (all of significant flows) has gross alpha monitoring
data from a representative point in the distribution system and the
result is 75% of the MCL (11 pCi/L), EPA expects that this data would
not be grandfathered, since it can not be ruled out that at least one
of the entry points has a contaminant level greater than the MCL. On
the other hand, if the distribution system sample baseline result is
below the detection limit and the State determines that, based on
aquifer and other characteristics, the entry points are expected to
have fairly uniform contaminant levels, then a State could reasonably
determine that this water system should be able to grandfather its
distribution system data. EPA will provide an Implementation Guidance
to further explain this issue after today's rule is final.
4. Does the Rule Allow Compositing of Samples?
Compositing allows a system to have combined samples analyzed to
reduce the costs of monitoring. Compositing of samples is done in the
laboratory. The 1976 rule allowed compositing for gross alpha and
allowed (but did not recommend) some compositing for beta/photon
emitters. Compositing is essentially an issue for the initial round of
monitoring for systems without data to grandfather. Once decreased
monitoring is in effect, only a single sample will be required and
compositing will not be an issue. In general, there are three kinds of
compositing: combining samples taken from the same sampling point from
different quarters (temporal compositing), samples taken in the same
quarter from different sampling points within a system (spatial
compositing), and samples taken from different water systems each
having one well (inter-system compositing). Inter-system and spatial
compositing are not allowed in today's rule, since this kind of
compositing defeats the purpose of monitoring at each entry point to
the distribution system.
Because compositing lessens the burden on systems and allows for
adequate monitoring reliability in some situations, temporal
compositing is allowed under circumstances in which the detection limit
is low compared to the MCL. In particular, temporal compositing is
allowed for uranium, gross alpha radium-226 (provided a DL of 1 pCi/L
is met) and radium-228 (provided a DL of 1 pCi/L is met). While

[[Page 76727]]

compositing is allowed under these circumstances, compositing of
several samples taken at different times provides less information than
individual analysis of the samples. For example, if contaminant levels
vary appreciably with pumping rates and pumping rates are seasonal,
compositing will hide this potentially significant variance.
Additionally, if a State allows a system with low contaminant levels to
base compliance on two results from different quarters, compositing may
not be desirable. If a State wishes to be more stringent and use the
highest result of four initial samples to set future monitoring
frequency, compositing is not appropriate. However, under some
conditions, States may wish to allow water systems to have their
samples composited before analysis.
Commenters generally agreed that spatial monitoring was
impractical, since it would provide limited information on contaminant
levels at individual entry points. Some commenters suggested that the
six month holding time for gross alpha would necessitate compositing
twice, two samples in the first six months and two in the second six
months. Although this type of compositing would be allowed, EPA
disagrees that this is necessary, since, for statistical reasons,
analysis of four composited samples taken in four different quarters
will achieve results of comparable quality (assuming that the analysis
is done within the same year that the first sample is taken) to
individual analyses of four samples using six month holding times. For
this reason, annual compositing at a single entry point is allowed for
gross alpha. While several commenters were desirous of maximum
compositing flexibility, the technical limitations described rule out
some types of compositing, specifically spatial and inter-system
compositing.
5. Interpretation of Analytical Results
The Agency recognizes that States have interpreted radionuclide
analytical results in a variety of ways, including adding or
subtracting standard deviations from the analytical results. The Agency
believes that compliance and reduced monitoring frequencies should be
calculated based on the ``analytical result(s)'' as stated in
Sec. 141.26(c)(3). It is EPA's interpretation that the analytical
result is the number that the laboratory reports, not including (i.e.
not adding or subtracting) the standard deviation. For example, if a
laboratory reports that the gross alpha measurement for a sampling
point is 7 2 pCi/L, then compliance and reduced monitoring
would be calculated using a value of 7 pCi/L.

K. Can My Water System Use Point-of-Use (POU), Point-of-Entry (POE)
\10\, or Bottled Water To Comply With This Regulation?
---------------------------------------------------------------------------

\10\ Point-of-entry (POE) treatment units treat all of the water
entering a household or other building, with the result being
treated water from any tap. Point-of-use (POU) treatment units treat
only the water at a particular tap or faucet, with the result being
treated water at that one tap, with the other taps serving untreated
water. POE and POU treatment units often use the same technological
concepts employed in the analogous central treatment processes, the
main difference being the much smaller scale of the device itself
and the flows being treated.
---------------------------------------------------------------------------

EPA has listed: (1) POU ion exchange and POU reverse osmosis as
small system compliance technologies for combined radium-226 and
radium-228, and beta particle and photon radioactivity; and (2) POU
reverse osmosis as a small systems compliance technology for gross
alpha particle activity (63 FR 42032; on August 6, 1998, also see Table
I-6 and I-7)). While these POU technologies are not considered BAT for
large systems, they may be used as BAT under sections 1412 and 1415 of
the Act for systems serving 10,000 persons or fewer. Guidance documents
were published to support the small systems compliance technology lists
(``Small System Compliance Technology List for the Non-Microbial
Contaminants Regulated Before 1996,'' USEPA 1998f). The small system
compliance technology list described in section I.H., table I-6, of
today's final rule is identical to the 1998 list, with the exception of
the addition of small systems compliance technologies for uranium. See
section I.H. for details about the lists. POE technologies are not
being listed as small systems compliance technologies since they are
considered emerging technologies and due to concerns regarding waste
disposal and costs. POE technologies (and other technologies) may be
added in the future through small system compliance technology updates.
The authority for listing POU technologies as small system
compliance technologies comes from section 1412(b)(4)(e)(ii) of the
SDWA, which identifies both Point-of-Entry (POE) and Point-of-Use (POU)
treatment units as options for compliance technologies. The SDWA
identifies requirements that must be met when POU or POE units are used
by a water system to comply with an NPDWR. Section 1412(b)(4)(e)(ii)
stipulates that ``point-of-entry and point-of-use treatment units shall
be owned, controlled, and maintained by the public water system or by a
person under contract with the public water system to ensure proper
operation and maintenance and compliance with the MCL or treatment
technique and equipped with mechanical warnings to ensure that
customers are automatically notified of operational problems.'' Other
conditions in this section of the SDWA include the following: ``If the
American National Standards Institute has issued product standards
applicable to a specific type of POE or POU treatment unit, individual
units of that type shall not be accepted for compliance with a MCL or
treatment technique unless they are independently certified in
accordance with such standards.''
In order to list POU treatment units as compliance technologies,
EPA had to withdraw the part of Sec. 141.101 that prohibited POU
devices being used to comply with an MCL. To this end, a final rule was
published in the Federal Register on June 11, 1998 (EPA 1998g). For
more details on POU and POE devices, see the supporting guidance
document for the small system compliance technology lists (USEPA 1998f).
Public water systems are not allowed to use bottled water to comply
with an MCL (63 FR 31932; June 11, 1998). Bottled water may only be
used on a temporary basis to avoid unreasonable risks to health, e.g.,
as negotiated with the State or other primacy agency as part of the
compliance schedule period for an exemption or variance.

L. What Do I Need To Tell My Customers?

1. Consumer Confidence Reports
On August 19, 1998, EPA issued Subpart O, the final rule requiring
community water systems to provide annual reports on the quality of
water delivered to their customers (63 FR 44512). The first Consumer
Confidence Reports (CCRs) were to be made available to customers by
October 19, 1999, and now they are due each year by July 1
(Sec. 141.152(a)). In these reports, systems must provide, among other
things, the levels and sources of all detected contaminants and a
description of the potential health effects of any contaminant found at
levels that violate EPA or State rules, as part of a broader
description of the violation and efforts to remedy it. For MCL or
treatment technique violations, specific ``health effects language'' in
Appendix A of Subpart O must be included verbatim in the report.
Today's rule updates the Appendix to include health effects language
and ``likely source''

[[Page 76728]]

information for uranium. This language is consistent both with
previously published health effects language for other radionuclides
and with the language now required by the Public Notification Rule.
Table I-10 shows the health effects language required for the
radionuclides for the purposes of CCR and public notification.

Table I-10.--Standard Health Effects Language for CCR and Public
Notification
------------------------------------------------------------------------
Standard health effects language for
Contaminant CCR and public notification
------------------------------------------------------------------------
Beta/photon emitters.............. Certain minerals are radioactive and
may emit forms of radiation known
as photons and beta radiation. Some
people who drink water containing
beta and photon emitters in excess
of the MCL over many years may have
an increased risk of getting
cancer.
Alpha Emitters.................... Certain minerals are radioactive and
may emit a form of radiation known
as alpha radiation. Some people who
drink water containing alpha
emitters in excess of the MCL over
many years may have an increased
risk of getting cancer.
Combined Radium (-226 & -228)..... Some people who drink water
containing radium 226 or 228 in
excess of the MCL over many years
may have an increased risk of
getting cancer.
Uranium........................... Some people who drink water
containing uranium in excess of the
MCL over many years may have an
increased risk of getting cancer
and kidney toxicity.
------------------------------------------------------------------------

2. Public Notification
Sections 1414(c)(1) and (c)(2) of the SDWA, as amended in 1996,
require that public water systems notify their customers when they are
in violation of NPDWRs. In the case of the radionuclides NPDWRs, this
only applies to community water systems. On May 4, 2000, EPA revised
the minimum requirements that public water systems must meet for public
notification of violations of EPA's drinking water standards and other
situations that pose a risk to public health from the drinking water.
These revisions were promulgated under the Public Notification Rule
(PNR), under 40 CFR Part 141, Subpart Q. Water systems must begin to
comply with the new regulations on October 31, 2000 (if they are in
jurisdictions where the program is directly implemented by EPA), or on
the date a primacy State adopts the new requirements (but not later
than May 6, 2002). Until the effective date of the new requirements,
water systems must continue to comply with the requirements under
Sec. 141.32. Subsequent EPA drinking water regulations that affect
public notification requirements will amend the PNR as a part of each
individual rulemaking.
Public notification of drinking water violations is an important
part of the ``public right to know'' provisions of the 1996 Amendments
to the Safe Drinking Water Act. The PNR sets the requirements that
public water systems must follow regarding the form, manner, frequency,
and content for public notifications. These requirements apply to
owners and operators of, in the case of the radionuclides NPDWRs,
community water systems. The PNR requires that any regulated system
notify its customers when: (1) A violation of a NPDWR occurs; (2) the
system obtains a variance or an exemption from a NPDWR; or (3) the
system is facing another situation posing a significant risk to public
health.
Depending on the severity of the situation, water suppliers have
from 24 hours to one year to notify their customers after a violation
occurs. EPA specifies three categories, or tiers, of public
notification. Depending under which tier a violation situation falls,
water systems have different amounts of time to distribute and ways to
deliver the notice:
Immediate Notice (Tier 1): Any time a situation occurs
where there is the potential for human health to be immediately
impacted, water suppliers have 24 hours to notify people who may drink
the water of the situation. Water suppliers must use media outlets such
as television, radio, and newspapers, post their notice in public
places, or personally deliver a notice to their customers in these
situations.
Notice ``as soon as possible'' (Tier 2): Any time a water
system provides water with levels of a contaminant that exceed EPA or
State standards or that hasn't been treated properly, but that does not
pose an immediate risk to human health, the water system must notify
its customers as soon as possible, but within 30 days of the violation.
Notice may be provided via the media, posting, or through the mail.
Annual Notice (Tier 3): When water systems violate a
drinking water standard that does not have a direct impact on human
health (for example, failing to take a required sample on time) the
water supplier has up to a year to provide a notice of this situation
to its customers. The extra time gives water suppliers the opportunity
to consolidate these notices and send them with annual water quality
reports (consumer confidence reports (CCR)), if the CCR meets the PNR
timing, content, and distribution requirements.
The PNR lists the currently regulated radionuclides (combined
radium-226 and radium-228, gross alpha, and beta particle and photon
radioactivity) as being subject to ``Tier 2'' public notice
requirements for MCL violations and ``Tier 3'' public notice
requirements for violations of the monitoring and testing procedure
requirements. Today's rule does not change this designation for the
currently regulated radionuclides and adds uranium to the list of
contaminants subject to Tier 2 requirements for MCL violations and Tier
3 requirements for violations of the monitoring and testing procedure
requirements.
The elements to be included in each public notice are specified
under Sec. 141.205(a). All notices must include:
A description of the violation that occurred, including
the potential health effects (as specified in appendix B to subpart Q
for MCL violations and the standard language under Sec. 141.205(d)(2)
for monitoring violations);
The population at risk and if alternate water supplies
need to be used;
What the water system is doing to correct the problem;
Actions consumers can take;
When the violation occurred and when the system expects it
to be resolved;
How to contact the water system for more information; and
Standard language encouraging broader distribution of the notice.
The standard health effects language used for public notification
is the same as that for CCR, which is provided in Table I-10.
The public notice requirements under 40 CFR 141.203(b)(1) are such
that the public water system must provide a Tier 2 public notice to
persons served as soon as practical, but no later than 30 days after
the system learns of the violation. Posted notices are required to
remain in place for as long as the

[[Page 76729]]

violation or situation persists, but in no case for less than seven
days, even if the violation or situation is resolved. The PNR under
Sec. 141.203(b)(2) also requires the public water system to repeat the
notice every three months for as long as the violation persists. In
contrast, the current rule requires a newspaper notice within 14 days,
a notice mailed to all bill-payers within forty-five days, and a repeat
notice mailed every three months thereafter until the violation is
resolved.
The public notification requirement gives the primacy agency
discretion, in appropriate circumstances, to extend the time period
allowed for the Tier 2 notice from 30 days to up to three months for
the initial notice and to allow repeat notice less frequently than
every three months (but no less than once per year). Permission must be
granted in writing. Although the discretion given to the primacy agency
is fairly broad, the rule specifically disallows extensions of the 30-
day deadline for the initial public notice for any unresolved
violation. The PNR also does not allow primacy agencies to establish
regulations or policies that automatically give ``across-the-board''
extensions or reductions in the repeat notice frequency for all the
other violations.
For the most up-to-date version of the CCR and PNR tables that will
be published in the July edition of the Code of Federal Regulations
(appendix A to subpart O, and appendices A and B to subpart Q of 40 CFR
part 141), visit EPA's Office of Ground Water and Drinking Water's
website at ``http://www.epa.gov/safewater/tables.html.'' These on-line
tables incorporate changes on an on-going basis.

M. Can My Water System Get a Variance or an Exemption From an MCL Under
Today's Rule?

There are two kinds of variances applicable to public water
systems: ``regular variances,'' which are usually referred to simply as
``variances,'' and ``small systems variances.'' The currently regulated
radionuclides are already subject to the provisions for variances and
exemptions and nothing in today's rule changes these provisions. The
regular variances and exemptions provisions will be discussed later in
this section.
As discussed in the NODA, the ``Small Systems Compliance Technology
List'' (SSCTL) for combined radium-226 and -228, gross alpha particle
activity, and beta particle/photon emitter radioactivity was published
in the Federal Register on August 6, 1998 (63 FR 42032), as required by
the amended SDWA. The SSCTL list for uranium was published for comment
in the radionuclides NODA.
The 1996 SDWA identifies three categories of small drinking water
systems, those serving populations between 25-500, 501-3,300, and
3,301-10,000. In addition to BAT determinations, the SDWA directs EPA
to make technology assessments for each of the three small system size
categories in all future regulations establishing an MCL or treatment
technique. Two classes of small systems technologies are identified for
future NPDWRs: small system compliance technologies and small system
variance technologies.
Small system compliance technologies (``compliance technologies'')
may be listed for NPDWRs that promulgate MCLs or treatment techniques.
In the case of an MCL, ``compliance technology'' refers to a technology
or other means that is affordable for the appropriate small systems (if
applicable) and that achieves compliance. Possible compliance
technologies include packaged or modular systems and point-of-entry
(POE) or point-of-use (POU) treatment units, as described previously.
Small system variance technologies (``variance technologies'') are
only specified for those system size/source water quality combinations
for which no technology meets all of the criteria for listing as a
compliance technology (section 1412(b)(15)(A)). Thus, the listing of a
compliance technology for a size category/source water combination
prohibits the listing of variance technologies for that combination.
While variance technologies may not achieve compliance with the MCL or
treatment technique requirement, they must achieve the maximum
reduction that is affordable considering the size of the system and the
quality of the source water. Variance technologies must also achieve a
level of contaminant reduction that is ``protective of public health''
(section 1412(b)(15)(B)). The process for determining small system
compliance technologies and small system variance technologies is
described in more detail in the guidance document, ``Small System
Compliance Technology List for the Non-Microbial Contaminants Regulated
Before 1996'' (USEPA 1998f).
In the case of the currently regulated radionuclides, i.e.,
combined radium-226 and -228, gross alpha particle activity, and total
beta particle and photon radioactivity, there are no variance
technologies allowable since the SDWA (section 1415(e)(6)(A))
specifically prohibits small system variances for any MCL or treatment
technique which was promulgated prior to January 1, 1986. The Variance
and Exemption Rule describes EPA's interpretation of this section in
more detail (see 63 FR 19442; April 20, 1998).
Stakeholders provided input regarding the small system compliance
technologies for combined radium-226 and -228, gross alpha emitters,
and beta particle and photon radioactivity, and uranium that are listed
in section I.H. The small system compliance technologies for the
radionuclides regulated since 1976 were listed and described in the
Federal Register on August 6, 1998 (63 FR 42032) and in an accompanying
guidance manual (EPA 1998b). Small systems compliance technologies for
uranium were evaluated subsequent to the 1998 list, and presented in
the Small Systems Compliance Technology List for the Radionuclides Rule
(USEPA 1999a). Small systems compliance technologies for uranium were
evaluated in terms of each technology's removal capabilities,
contaminant concentration applicability ranges, other water quality
concerns, treatment costs, and operational/maintenance requirements.
This list was published for comment in the April 21, 2000, Notice of
Data Availability (USEPA 2000e). No comments were received.
Small system compliance technology lists are technology specific,
but not product (manufacturer) specific. Product specific lists were
determined to be inappropriate due to the potential resource
intensiveness involved. Information on specific products will be
available through another mechanism. EPA's Office of Research and
Development has a pilot project under the Environmental Technology
Verification (ETV) Program to provide treatment system purchasers with
performance data from independent third parties.
The currently regulated radionuclides are already subject to the
provisions for ``regular variances'' and exemptions. Uranium will be
subject to the same provisions. Variances generally allow a system to
provide drinking water that may be above the maximum contaminant level
on the condition that the quality of the drinking water is still
protective of public health. The SDWA (1415(a)) requires that any
system obtaining a variance must enter into a compliance schedule with
the primacy entity as a condition of the variance. An exemption, on the
other hand, is intended to allow a system with compelling circumstances
an extension of time before the system must comply with applicable SDWA
requirements.

[[Page 76730]]

An exemption is limited to three years after the otherwise applicable
compliance date, although extensions up to a total of six additional
years may be available to small systems under certain conditions.

N. How Were Stakeholders Involved in the Development of This Rule?

EPA has consulted with a broad range of stakeholders and technical
experts. EPA held a two-day stakeholders meeting on the radionuclides
rule in Washington, DC on December 11-12, 1997. The meeting was
announced in the Federal Register and open to any one interested in
attending in person or by phone. During the meeting, EPA discussed a
range of regulation development issues with the stakeholders, including
the statutory requirements, the stipulated agreement, MCLs for each of
the radionuclides, new scientific information on health effects,
occurrence, analytical methods, treatment technologies, and the current
and proposed monitoring framework. The presentations generated useful
discussion and provided feedback to EPA regarding technical issues,
stakeholder concerns and possible regulatory options. Participants in
EPA's stakeholder meeting included representatives from the Association
of Metropolitan Water Agencies (AMWA), Association of State Drinking
Water Administrators (ASDWA), American Water Works Association (AWWA),
National Association of Water Companies, State departments of
environmental protection, State health department, State drinking water
programs, Federal agencies, environmental groups, and local water
systems. The public docket for this final rulemaking contains the
meeting summary for EPA's stakeholder meeting on radionuclides in
drinking water.
In addition, during the regulation development process, EPA gave
presentations on the radionuclides regulation at meetings of the AWWA,
ASDWA and EPA State/Regional conferences, and met with States from
Regions 2, 3, 7, and 8 regarding radionuclides issues and the upcoming
final rule. EPA participated in AWWA's Technical Advisory Workgroup
(TAW), which meets annually to discuss technical issues including
treatment, occurrence, and health risks. State public health
departments and drinking water program representatives of both large
and small drinking water districts participated in TAW meetings. EPA
also held frequent conference calls with interested State drinking
water programs about the development of the rule. In addition, EPA made
presentations and received input at Tribal meetings in Nevada, Alaska,
and California. Finally, EPA held a one-day meeting with associations
that represent State, county, and local government elected officials on
May 30, 2000, and discussed five upcoming drinking water regulations,
including radionuclides. See section V.I ``Executive Order 13132'' for
more information about the meeting.
The Agency utilized the feedback received from the stakeholders
during all these meetings in developing today's final rule.

O. What Financial Assistance Is Available for Complying With This Rule?

Various Federal programs exist to provide financial assistance to
State, local, and Tribal governments to administer and comply with this
and other drinking water rules. The Federal government provides funding
to States and Tribes that have a primary enforcement responsibility for
their drinking water programs through the Public Water Systems
Supervision (PWSS) Grants program. Additional funding is available from
other programs administered either by EPA or other Federal agencies.
These include the Drinking Water State Revolving Fund (DWSRF) and
Housing and Urban Development's Community Development Block Grant
Program. For example, the SDWA authorizes the Administrator of the EPA
to award capitalization grants to States, which in turn can provide low
cost loans and other types of assistance to eligible public water
systems. The DWSRF assists public water systems with financing the
costs of infrastructure needed to achieve or maintain compliance with
SDWA requirements. Each State has considerable flexibility to determine
the design of its program and to direct funding toward its most
pressing compliance and public health protection needs. States may
also, on a matching basis, use up to ten percent of their DWSRF
allotments for each fiscal year to assist in running the State drinking
water program.
Under PWSS Program Assistance Grants, the Administrator may make
grants to States to carry out public water system supervision programs.
States may use these funds to develop primacy programs. States may
``contract'' with other State agencies to assist in the development or
implementation of their primacy program. However, States may not use
program assistance grant funds to contract with regulated entities
(i.e., water systems). PWSS Grants may be used by States to set-up and
administer a State program which includes such activities as: public
education, testing, training, technical assistance, developing and
administering a remediation grant and loan or incentive program
(excludes the actual grant or loan funds), or other regulatory or non-
regulatory measures.

P. How Are the Radionuclides MCLs Used Under the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA)?

The framework for the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP) includes the
expectation that contaminated ground waters will be returned to
beneficial uses whenever practicable (see Sec. 300.430(a)(1)(iii)(F)).
Section 121(d) of CERCLA requires on-site remedial actions to attain
MCLGs and water quality standards under CWA when relevant and
appropriate. The NCP (Sec. 300.430(e)(2)(i)(B) and (C) clarify that
MCLs or non-zero MCLGs established under SDWA will typically be
considered relevant and appropriate cleanup levels for ground waters
that are a current or potential source of drinking water.
EPA's guidance on complying with these requirements are contained
in an EPA document entitled ``Presumptive Response Strategy and Ex-Situ
Treatment Technologies for Contaminated Ground Water at CERCLA Sites,
Final Guidance,'' (October 1996. OSWER Directive 9283.1-12). A
discussion of the flexibility of EPA's guidance under CERCLA on the
attainment of drinking waters in ground water is contained in section
2.6 ``Areas of Flexibility in Cleanup Approach'' (pp 15-19) of the 1996
OSWER directive. The discussion in the 1996 OSWER directive regarding
monitored natural attenuation and determining beneficial uses of
groundwater has been updated by the following EPA guidance documents:
(1) ``Use of Monitored Natural Attenuation at Superfund, RCRA
Corrective Action, and Underground Storage Tank Sites'' (April 1999.
Final OSWER Directive 9200.4-17P), and (2) ``The Role of CSGWPPs in EPA
Remediation Programs'' (April 4, 1997, OSWER Directive 9283.1-09).

Q. What Is the Effective Date and Compliance Date for the Rule?

Much of today's rule will involve retaining current elements of the
radionuclides NPDWR. Those portions of the final rule that are
unaffected by the upcoming regulatory changes are

[[Page 76731]]

already in effect. MCLs for gross alpha, beta particle and photon
radioactivity, and combined radium-226 and -228 will be unchanged and
are already in effect. Regarding water systems that are currently out
of compliance with the existing NPDWRs for gross alpha, combined
radium-226 and -228, and/or beta particle and photon radioactivity,
States with primacy and EPA will renegotiate, as necessary, enforcement
actions that put systems on compliance schedules as expeditiously as
possible.
Under the Safe Drinking Water Act, the final rule becomes effective
three years after promulgation December 8, 2003. Under the Standard
Monitoring Framework (SMF), systems usually have three years to
complete the initial monitoring cycle of four consecutive quarterly
samples. In order to synchronize the monitoring periods for
radionuclides with the Standardized Monitoring Framework and alleviate
potential laboratory capacity problems, the end of the initial
monitoring period will be December 31, 2007. EPA expects that States
will phase-in monitoring over this period and determine compliance upon
completion of each water system's initial monitoring schedule. For
example, the fraction of water systems that begin monitoring in the
first year would have compliance determinations made at the end of the
first year, based upon the average results of the four quarterly
samples. New monitoring includes initial monitoring for uranium, the
new monitoring requirements for radium-228, and new initial monitoring
under the requirements for entry points. Data grandfathering discretion
for existing monitoring data to determine future monitoring schedules
is discussed in sections I.D and I.J. Combined radium-226 and radium-
228 MCL violations which result from the new requirement for separate
radium-228 monitoring will be treated as ``new violations'' and will be
on the same schedule as other new violations (e.g. uranium). Water
systems with existing monitoring data for radium-228 and uranium that
demonstrate that they are not in compliance with the MCL will be out of
compliance on the effective date of the rule.

R. Has EPA Considered Laboratory Approval/Certification and Laboratory
Capacity?

The ultimate effectiveness of the approved regulations depends upon
the ability of laboratories to reliably analyze contaminants at
relatively low levels. The Drinking Water Laboratory Certification
Program is intended to ensure that approved drinking water laboratories
analyze regulated drinking water contaminants within acceptable limits
of performance. The Certification Program is managed through a
cooperative effort between EPA's Office of Ground Water and Drinking
Water and the Office of Research and Development. The program
stipulates that laboratories analyzing drinking water compliance
samples must be certified by U.S. EPA or the State. The program also
requires that certified laboratories must analyze Proficiency Testing
(PT) samples [formerly called Performance Evaluation (PE) samples], use
approved methods and pass periodic on-site audits.
1. Laboratory Approval/Certification
As discussed in the April 21, 2000 NODA, EPA recently privatized
the PT program, including the Water Supply (WS) studies. The decision
to privatize the PT studies programs was announced in the Federal
Register on June 12, 1997 (62 FR 32112). The notice indicated that in
the future the EPA would issue standards for the operation of the
program, while the National Institute of Standards and Technology
(NIST) would develop standards for private sector PT suppliers and
would evaluate and accredit PT suppliers. The private sector would
develop and manufacture PT samples and conduct PT studies.
2. Laboratory Capacity: Laboratory Certification and PT Studies
The availability of laboratories is also dependent on laboratory
certification efforts in the individual States with regulatory
authority for their drinking water programs. Until June of 1999, a
major component of many of these certification programs was their
continued participation in the current EPA Water Supply (WS) PT
program. As discussed previously, NIST is administering the program to
accredit a provider for PT samples for radionuclides. States also have
the option of approving their own PT sample providers. The extent to
which the PT program will affect short-term and long-term laboratory
capacity for radionuclides will be assessed after PT providers are
approved by NIST or the States. However, EPA anticipates that
radionuclide PT samples will be available in time to allow for
laboratory certification before compliance monitoring is required.
3. Summary of Major Comments Regarding Laboratory Capacity and EPA
Responses
In the April 21, 2000 NODA, the Agency stated that it is difficult
to ascertain how and if externalization of the PT program will affect
radiochemical laboratory capacity and the cost of radiochemical
analyses. In the absence of definitive information, the Agency
solicited public comments on this subject. The Agency stated in the
NODA that it recognized that PT externalization may be an
implementation issue for at least three reasons:
The externalization of the radionuclides PT studies
program may cause short-term disruption in laboratory accreditation;
Requiring NTNCWSs to monitor under the Standard Monitoring
Framework will add approximately 20,000 systems to the universe of
systems that are already required to monitor;
And the radon rule will be implemented at approximately
the same time as the radionuclides rule.
To alleviate potential laboratory capacity problems that could
result, the Agency solicited comments on whether or not to extend the
initial monitoring period to four years (instead of three years). Of
the 70 commenters who provided comments on the radionuclides NODA, 15
commented on laboratory externalization and its related issues. The
major concerns raised by the commenters and the Agency's responses to
them are provided below.
a. Laboratory Certification, Availability of PT Samples and Costs
of PT Samples: Several commenters noted there is currently no
certification process through which laboratories can receive State
certification for radionuclide analyses due to the lack of availability
of PT samples. Some commenters noted that only one PT provider has
volunteered to provide PT samples for radionuclides and based on their
inquiries, PT sample costs are too high. Commenters believe the high
costs of PT samples will affect the resulting costs of the
radiochemical analyses (by increasing operational costs). Several
commenters felt EPA should reconsider the privatization of PT program.
Commenters stated that EPA must ensure that an adequate number of
laboratories are available to perform accurate measurements and provide
data of good quality for compliance and enforcement efforts.
After evaluating public comment, EPA published its final decision
about the externalization of the PT Program in the June 12, 1997 final
notice (62 FR 32112). Currently, the PT program for radionuclides is
being privatized, i.e., operated by an independent third party provider
accredited by the National Institute of Standards and Technology
(NIST). EPA believes this program will

[[Page 76732]]

ensure the continued viability of the existing PT programs, with EPA
maintaining oversight. NIST is in the process of approving a provider
for PT samples for radionuclides. To alleviate concerns about the costs
of PT samples, States have the option to approve PT sample provider(s)
themselves. The Agency anticipates that radionuclide PT samples will be
available in time to allow for laboratory certification before
compliance monitoring is required.
b. Laboratory Capacity: Commenters stressed the impact that the
externalization of the PT program, this regulation and the radon
regulation would have on laboratory capacity and workloads of the
laboratories. Some commenters felt the externalization and high costs
of PT samples would decrease the number of radiochemical laboratories
and in affect decrease laboratory capacity. Also, commenters felt that
if EPA required 48-72 hour turn around times for gross alpha (to catch
the alpha particle contribution from radium-224) or monitoring of
regulated radionuclides by NTNCWSs, radiochemical laboratories would
not be able to address the additional demand for analytical services.
EPA agrees that laboratory capacity could be effected by the
externalization of the PT program. In an effort to alleviate potential
laboratory capacity problems, EPA has agreed to extend the initial
monitoring period from three to four years. Extending the initial
monitoring period will spread the burden on the laboratories as well as
the costs associated with the monitoring. In addition, EPA is allowing
systems to grandfather existing data on currently regulated
radionuclides and composite under certain circumstances (for more
information on compositing and grandfathering, see section I.J. In
addition, because EPA has decided not to require a 48 to 72 hour turn
around time for gross alpha particle activity nor to regulate NTNCWSs,
the potential burden on laboratory capacity should be alleviated.

II. Statutory Authority and Regulatory Background

A. What Is the Legal Authority for Setting National Primary Drinking
Water Regulations (NPDWRs)?

The SDWA requires EPA to promulgate regulations pertaining to
public water systems. Specifically, section 1412(b)(4) requires that
EPA set a health-based goal called a maximum contaminant level goal
(MCLG) as a target for setting an enforceable standard, the maximum
contaminant level (MCL). The MCLG is determined by studies of the
health effects of contaminants on animals under laboratory conditions
or humans via epidemiological studies. The MCLG is the level at which
no known or anticipated adverse effects on the health of persons occur
and which allows an adequate margin of safety. The Safe Drinking Water
Act requires EPA to set the MCL as close to the MCLG as is
``feasible,'' which is defined as ``feasible with the use of the best
technology, treatment techniques and other means which the
Administrator finds, after examination for efficacy under field
conditions and not solely under laboratory conditions, are available
(taking cost into consideration) * * *'' [section 1412(b)(4)(D)].
Additionally, section 1412(b)(6) provides that if the Administrator
determines that at the feasible level, the benefits do not justify the
costs, EPA can set a standard which maximizes the health risk reduction
benefits at a cost that is justified by the benefits. In today's rule,
EPA is invoking these authorities with respect to the uranium standard.
Section 1412 (b)(9) requires that any revisions to NPDWRs maintain or
provide for greater protection of the health of persons.

B. Is EPA Required To Finalize the 1991 Radionuclides Proposal?

The SDWA requires that EPA issue MCLGs for the currently regulated
radionuclides in drinking water and establish a NPDWR for uranium. When
EPA failed to finalize the 1991 proposal, a citizen group brought suit
to establish a schedule for finalizing the appropriate portions of the
proposal. Following the 1996 amendments to the SDWA, the plaintiffs and
EPA agreed on a schedule for completing the revisions to the
radionuclides rulemaking by either finalizing applicable parts of the
1991 proposal or affirming the validity of the current rule with an
explanation of why the current rule is preferable. With respect to
uranium, EPA has no current rule, and is required to finalize a uranium
regulation on the same schedule as gross alpha particle activity,
combined radium-226 and -228, and beta particle and photon
radioactivity. This agreement was reflected in a stipulation of the
parties in litigation in U.S. District Court in Oregon.

III. Rule Implementation

A. What Are the Requirements for Primacy?

This section describes the regulations and other procedures and
policies primacy entities have to adopt, or have in place, to implement
today's final rule. States must continue to meet all other conditions
of primacy in 40 CFR part 142.
Section 1413 of the SDWA establishes requirements that primacy
entities (States or Indian Tribes) must meet to maintain primary
enforcement responsibility (primacy) for its public water systems.
These include:
(1) Adopting drinking water regulations that are no less stringent
than Federal NPDWRs in effect under sections 1412(a) and 1412(b) of the
Act,
(2) Adopting and implementing adequate procedures for enforcement,
(3) Keeping records and making reports available on activities that
EPA requires by regulation,
(4) Issuing variances and exemptions (if allowed by the State)
under conditions no less stringent than allowed by sections 1415 and
1416, and
(5) Adopting and being capable of implementing an adequate plan for
the provision of safe drinking water under emergency situations.
40 CFR part 142 sets out the specific program implementation
requirements for States to obtain primacy for the Public Water Supply
Supervision Program, as authorized under section 1413 of the Act. In
addition to adopting the basic primacy requirements, States may be
required to adopt special primacy provisions pertaining to a specific
regulation. These regulation-specific provisions may be necessary where
implementation of the NPDWR involves activities beyond those in the
generic rule. States are required by Sec. 142.12 to include these
regulation-specific provisions in an application for approval of their
program revisions. These State primacy requirements apply to today's
final rule, along with the special primacy requirements discussed below.
To implement today's final rule, States are required to adopt
revisions to Sec. 141.25--Analytical methods for radioactivity;
Sec. 141.26--Monitoring frequency and compliance requirements for
radioactivity in community water systems; appendix A to subpart O--
Regulated contaminants; appendix A to subpart Q--NPDWR violations and
other situations requiring public notice; appendix B to subpart Q--
Standard health effects language for public notification; Sec. 142.16--
Special primacy requirements; and new requirements Sec. 141.55--Maximum
contaminant level goals for radionuclides; and Sec. 141.66--Maximum
contaminant levels for radionuclides.

B. What Are the Special Primacy Requirements?

In addition to adopting drinking water regulations at least as
stringent as the

[[Page 76733]]

Federal regulations listed above, EPA requires that States adopt
certain additional provisions related to this regulation to have their
program revision application approved by EPA.
The State's request for approval must contain the following:
(1) If a State chooses to use grandfathered data in the manner
described in Sec. 141.26(a)(2)(ii)(C) of this chapter, then the State
must describe the procedures and criteria which it will use to make
these determinations (whether distribution system or entry point
sampling points are used).
(i) The decision criteria that the State will use to determine that
data collected in the distribution system are representative of the
drinking water supplied from each entry point to the distribution
system. These determinations must consider:
(A) All previous monitoring data.
(B) The variation in reported activity levels.
(C) Other factors affecting the representativeness of the data
(e.g. geology).
(2) A monitoring plan by which the State will assure all systems
complete the required monitoring within the regulatory deadlines.
States may update their existing monitoring plan or use the same
monitoring plan submitted for the requirements in Sec. 142.16(e)(5)
under the National Primary Drinking Water Regulations for the inorganic
and organic contaminants (i.e. the Phase II/V Rules). States may note
in their application any revision to an existing monitoring plan or
note that the same monitoring plan will be used. The State must
demonstrate that the monitoring plan is enforceable under State law.
There are many ways that a State may satisfy the special primacy
requirements. The Agency intends to issue guidance regarding ways to
satisfy these requirements, but States have the flexibility to develop
individual programs appropriate for the circumstances within each State.

C. What Are the Requirements for Record Keeping?

The current regulations in Sec. 142.14 require States with primacy
enforcement responsibility to keep records of analytical results to
determine compliance, system inventories, sanitary surveys, State
approvals, vulnerability determinations, monitoring requirements,
monitoring frequency decisions, enforcement actions, and the issuance
of variances and exemptions. These records include:
(1) Any determination of a system's vulnerability to contamination
by beta and photon emitters (Sec. 142.14(d)(4)); and
(2) Any determination that a system can reduce or increase
monitoring frequency for gross alpha particle activity, gross beta
particle and photon radioactivity, uranium, radium-226 and 228. The
records must include the basis for the decision, and the repeat
monitoring frequency (Sec. 142.14(d)(5)).
Since these requirements are generally included in
Sec. 142.14(d)(4) and (5), revisions to the rule are not necessary.

D. What Are the Requirements for Reporting?

Currently, States must report to EPA information under Sec. 142.15
regarding violations, variances and exemptions, enforcement actions and
general operations of State public water supply programs. These
reporting requirements remain unchanged and apply to the radionuclides
as with any other regulated contaminant.

E. When Does a State Have To Apply for Primacy?

The State must submit a request for approval of program revisions
that adopts the uranium MCL, implementing regulations, and other
revisions promulgated in today's final rulemaking within two years of
the publication date of today's rule unless EPA approves an extension
per Sec. 142.12(b). To maintain primacy for the Public Water Supply
Supervision (PWSS) Program and to be eligible for interim primacy
enforcement authority for future regulations, States must adopt today's
rule. Interim primacy enforcement authority allows States to implement
and enforce drinking water regulations once State regulations are
effective and the State has submitted a complete and final primacy
revision application. To obtain interim primacy, a State must have
primacy with respect to each existing NPDWR. Under interim primacy
enforcement authority, States are effectively considered to have
primacy during the period that EPA is reviewing their primacy revision
application.

F. What Are Tribes Required To Do Under This Regulation?

Currently, no federally recognized Indian tribes have primacy to
enforce any of the drinking water regulations. EPA Regions implement
the rules for all Tribes under section 1451(a)(1) of SDWA. Tribes would
need to submit a primacy application in order to have the authority to
implement the radionuclides NPDWRs. Tribes with primacy for drinking
water programs are eligible for grants and contract assistance (section
1451(a)(3)). Tribes are also eligible for grants under the Drinking
Water State Revolving Fund Tribal set aside grant program authorized by
SDWA section 1452(i) for public water system expenditures.

IV. Economic Analyses

Under Executive Order 12866, Regulatory Planning and Review, EPA
must estimate the costs and benefits of the finalized changes to the
Radionuclides NPDWRs and submit the impact analysis to the Office of
Management and Budget (OMB) as part of the rulemaking process. EPA has
prepared an Economic Analysis (USEPA 2000g) to comply with the
requirements of this Order. This section provides a summary of the
information from the economic analysis regarding estimates of the costs
and benefits related to the changes to the existing radionuclides
NPDWRs and the uranium NPDWR being finalized today. The economic
analysis is an update to the Health Risk Reduction and Cost Analysis
(USEPA 2000f) announced in the NODA (USEPA 2000e) and summarized in the
NODA's Technical Support Document (USEPA 2000h). The updates to the
economic analysis reflect comments received on the NODA. This section
will not repeat all of the material presented in the NODA and in some
cases will refer back to that notice. Changes made in response to
comments will be highlighted.

A. Estimates of Costs and Benefits for Community Water Systems

Two requirements under today's rule are expected to incur costs and
benefits: the adoption of the uranium MCL of 30 g/L and the
requirement for separate monitoring of radium-228, which is expected to
result in additional systems in violation of the combined radium-226/-
228 MCL of 5 pCi/L. EPA estimates that these requirements will result
in annual compliance costs of $81 million in 1999 dollars, with $25
million of this annual cost being due to mitigation of systems newly in
violation of the radium-226/-228 standard due to new monitoring
requirements, $51 million due to mitigation of systems in violation of
a uranium MCL of 30 g/L, $ 4.9 million due to monitoring and
reporting by CWSs, and $ 0.06 million due to new implementation costs
for States. While these represent new compliance costs, most water
systems will experience reduced compliance costs in the long-term
because of reduced monitoring frequency for systems with low
contaminant levels under the Standardized Monitoring Framework. The
basis for these estimates, and

[[Page 76734]]

alternate cost estimates using different assumptions are described
later in this section.
State implementation and CWS start up costs are estimated to be $10
million annually for the first three years. Of this $10 million,
approximately $ 0.25 million are State start up costs with the
remainder being comprised by CWS start up costs (USEPA 2000d). Over the
first twenty-three year period, the implementation costs for States and
CWSs are estimated to be $ 4.9 million annually (included in the annual
compliance costs reported previously). These costs include preparation
of the primacy application, training, planning, and other compliance
preparations, and monitoring and reporting costs for PWSs.
The treatment/non-treatment compliance unit costs and national
costing assumptions used in the Economic Analysis (USEPA 2000g) are
standard and are consistent with those used for estimating the costs of
compliance the other recently proposed drinking water rules. The
updated Technologies and Costs document (USEPA 2000i) provides unit
capital and ``operations & maintenance'' costs for water treatment
plants, including residuals disposal costs. Typical model small system
treatment costs ranged from $ 0.25 to $ 3 per kilogallon of water
treated, with associated annual per household costs ranging from $20 to
$250, with the value depending upon water system size and water
quality. Large system model unit costs ranged from $0.17 to $ 0.28 per
kilogallon treated, with associated annual per household costs ranging
from $14 to $23.
For various reasons (see the NODA's Technical Support Document for
details, USEPA 2000h), the estimate of monetized benefits associated
with compliance of today's rule are more uncertain than the costs
estimates. In the case of the requirement for separate monitoring for
radium-228, cancer risk reduction benefits of $1.7 million annually are
expected. While the net benefits for this monitoring change are
expected to be negative, this monitoring change is essential for
enforcing the combined radium-226/-228 standard. In the case of the
uranium standard, the benefits are difficult to monetize, since the
number of kidney toxicity cases avoided cannot be estimated using
current risk models. For this reason, the uranium kidney toxicity
benefits are considered to be ``non-quantified benefits'' for this
rule. As discussed in detail in part D of section I (``Rationale for
the Final Uranium MCL''), we consider these non-quantified kidney
benefits to be a significant part of this assessment of costs and benefits.
The uranium cancer risk reduction benefits are estimated to be $3
million annually, which, we reiterate, do not include the non-
quantified kidney toxicity risk reduction benefits. As discussed in the
NODA, there are significant uncertainties associated with any estimate
of drinking water benefits, including uncertainties in the unit risks
used to estimate risk reductions and the various health endpoints that
cannot yet be fully quantifitied.
Other non-quantified benefits include those related to the
technologies used to remove radium and uranium from ground water (e.g.,
water softening technologies like ion exchange, lime softening, and
membrane softening and iron removal technologies like green sand
filtration and oxidation/filtration). EPA does not have enough
information to estimate these benefits, but believes that they could be
significant. Examples of benefits related to water softening include
reductions in excessive calcium and manganese carbonate scaling in
distribution systems, water heaters, and boilers and reductions in soap
and detergent use. Examples of benefits related to iron removal include
improvements in color and taste and reduction in staining of clothes,
sinks, and basins.

B. Background

1. Overview of the 1991 Economic Analysis
Many of the options proposed in 1991 economic analysis are not
being finalized today. Today's discussion will focus on the analysis of
costs and benefits of the options that are being finalized: a final
uranium standard and separate monitoring for radium-228. The 1991
economic analysis (USEPA 1991) estimated the annual cost of compliance
with a uranium MCL of 20 g/L to be $55 million, affecting
approximately 1,500 systems, the vast majority of them being small
systems. The 1991 estimate of the annual cost of compliance with a
uranium MCL of 40 g/L was $23 million. The current estimate of
the cost of compliance with a uranium MCL of 20 g/L is $93
million, impacting 900 systems, most of them small.
2. Summary of the Current Estimates of Risk Reductions, Benefits, and Costs
Table IV-1 shows the summarized results for EPA's analysis of risk
reductions, benefits valuations, and costs of compliance (see USEPA
2000g for more detailed break-downs of the risk reductions, costs, and
benefits by system size). The risk reductions and cost estimates are
based on the estimated range of numbers of community water systems
predicted to be out of compliance with the uranium MCL of 30
g/L and the systems that are predicted to be out of compliance
with the current combined radium-226/-228 standard of 5 pCi/L because
of the new requirement for separate radium-228 monitoring. The best
estimate values shown are the midpoints from ranges that are based on
the two occurrence model methodologies described in the NODA (USEPA
2000e), the ``direct proportions'' and ``lognormal model'' approaches.
As described in the NODA, these two approaches are expected to serve as
``low-end'' and ``high-end'' occurrence estimates, respectively.
Eliminating the combined radium-226/-228 monitoring deficiency \11\
is predicted to lead to 295 (range of 270 to 320) systems out of
compliance with an MCL of 5 pCi/L, affecting 420,000 persons (range
380,000 to 460,000). A uranium MCL of 30 g/L is predicted to
impact 500 systems (range 400 to 590), affecting 620,000 persons (range
130,000 to 1,100,000). The estimates of occurrence and risk reductions
for a uranium MCL of 30 g/L are based on the assumption that
the activity-to-mass ratio in drinking water is 0.9 g/pCi.
Based on the available information, the average activity-to-mass ratio
for the various uranium isotopes in drinking water typically varies
from 0.7 to 1.5 pCi/g.
---------------------------------------------------------------------------

\11\ The monitoring deficiency is corrected by requiring the
separate analysis of radium-228 for systems with gross alpha levels
below 5 pCi/L and radium-226 levels below 3 pCi/L.
---------------------------------------------------------------------------

The estimated cancer morbidity risk reduction for the option
addressing the combined radium monitoring deficiency is 0.4 (0.3 to
0.5) cancer cases avoided annually, with an associated annual monetized
benefit of $1.7 million (range of $1.2 to $2.2 million). The annual
cancer morbidity risk reduction estimated for a uranium MCL of 30
g/L is 0.9 cases/year (range 0.1 to 1.6). The associated
annual monetized benefit related to uranium cancer risk reduction is $3
million (range from $0.2 to $6 million) \12\. The risk reductions and

[[Page 76735]]

benefits shown for uranium do not include those related to kidney
toxicity, which are non-quantifiable (cases avoided cannot be
estimated). As discussed in section I.D.2 of today's final rule, these
non-quantifiable benefits are projected to be preventing a series of
adverse affects on the functioning of the kidney such as proteinuria
(e.g., reabsorption deficiency or leakage of albumin), that could
ultimately lead to a more widespread breakdown in kidney tubular
function. Such effects on tubular function would be manifested by an
impaired ability of the kidneys to filter and reabsorb nutrients and to
excrete urine.
---------------------------------------------------------------------------

\12\ The Agency has agreed to consider the July 27, 2000
recommendations of its Science Advisory Board (SAB) concerning
discounting of benefits in future drinking water regulations. In
particular, the SAB recommended that quantitative adjustments to
benefits be considered with respect to timing of risk (e.g.,
consideration of a lag or latency period before the resulting cancer
fatality) and income growth. The SAB also recommended that other
possible adjustments to benefits estimates be considered in a
qualitative manner. We have not made any such adjustments to the
benefits associated with today's rule since the principal benefits
are non-quantifiable (avoidance of kidney toxicity due to reductions
in exposure to uranium). We do not believe that adjustments to these
monetized cancer avoidance benefits estimates for either timing or
income growth would materially affect our benefits assessment or
decisions resulting from overall consideration of the benefits and
costs of the regulatory standard.
---------------------------------------------------------------------------

Annual compliance costs are estimated to be $25 million (range $16
to $35 million) for the option addressing the combined radium
monitoring deficiencies. Annual compliance costs for the uranium NPDWR
are predicted to be $51 million (range from $9 to $92 million). In
addition to these mitigation related compliance costs, water systems
are expected to incur $4.9 million annually in monitoring and reporting
costs. As demonstrated by this analysis the estimated range of central-
tendency annual compliance costs exceed the ranges of central-tendency
annual monetized benefits for both provisions finalized today.

Table IV-1.--Summary of Costs and Benefits for Community Water Systems Predicted To Be Impacted by the Regulatory Options Being Considered for
Finalization
--------------------------------------------------------------------------------------------------------------------------------------------------------
Best-estimate
Estimated lifetime Best-estimate value of of annual
Numbers of systems radiogenic cancer Total cancer cases avoided cancer cases, compliance
Options impacted \1\ morbidity risk at MCL avoided annually (fatal in millions of $/ costs, in
(population exposed 2, 3, 4 cases) year) millions of $/
above MCL) year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Systems predicted to be impacted by corrections to the monitoring deficiencies for combined radium-226 and -228
--------------------------------------------------------------------------------------------------------------------------------------------------------
Eliminate combined radium monitoring 295 systems (420 K 1 x 10-4............... 0.4.................... 1.7................... 25
deficiency. persons). (0.3)..................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Systems predicted to be out of compliance with proposed options for uranium MCL
--------------------------------------------------------------------------------------------------------------------------------------------------------
Uranium at 30 g/L.......... 500 systems (620 K 1 x 10-4 (assumes 30 0.9.................... 3.0................... 51
persons). pCi/). (0.6).................. Kidney toxicity
(Total Number of kidney benefits range from
toxicity cases cannot prevention of mild
be accurately proteinurea to
estimated, but possible more serious
expected to be impaired kidney
substantial). tubular function.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes: Compliance costs do not include monitoring and reporting costs, which comprise an additional $5 million annually. Ranges based on directly
proportional versus lognormal distribution approach.
\1\ Compared to the initial baseline (i.e., occurrence data are adjusted to eliminate existing MCL violations) for combined radium. Occurrence data is
unadjusted for uranium options.
\2\ 1 x 10 is equivalent to ``one in ten thousand'', EPA's usual upper limit of acceptable cancer incidence (morbidity) risk for contaminants in
drinking water.
\3\ These risk estimates are based on several simplifying assumptions and are only meant to be illustrative. The reported combined radium risk is based
on an ``occurrence weighted average'' for radium-226 and radium-228 (2.3 x 10-5 per pCi/L). The ``best-estimate'' for a particular situation would
depend on the actual levels of Radium226 and Radium228 that comprise the combined level of 5 pCi/L. Regarding uranium risks, since the individual
uranium isotopes that make up naturally-occurring uranium have cancer morbidity risks that are similar in magnitude (6.4 to 7.1 x 10-11 per pCi), the
assumptions about isotopic prevalence are not important. Here, we assumed that the simple average applied (3.83 x 10-6 per pCi/L).
\4\ Kidney toxicity is not considered in this estimate of risk or monetized benefits.

3. Uncertainties in the Estimates of Benefits and Cost
The models used to estimate costs and benefits related to
regulatory measures have uncertainty associated with the model inputs.
The types and uncertainties of the various inputs and the uncertainty
analyses for risks, benefits, and costs are qualitatively discussed in
this section.
a. Uncertainties in Risk Reduction and Benefits Estimates
For each individual radionuclide, EPA developed a central-tendency
risk coefficient that expresses the estimated probability that cancer
will result in an exposed individual per unit of radionuclide activity
(e.g., per pCi/L) over the individual's lifetime (assumed to be 70
years). Two types of risks are considered, cancer morbidity, which
refers to any incidence of cancer (fatal or non-fatal), and cancer
mortality, which refers to a fatal cancer illness. For this analysis,
we used the draft September 1999 risk coefficients developed as part of
EPA's revisions to Federal Guidance Report 13 (FGR-13, EPA 1999e). FGR-
13 compiled the results of several models predicting the cancer risks
associated with radioactivity. The cancer sites considered in these
models include the esophagus, stomach, colon, liver, lung, bone, skin,
breast, ovary, bladder, kidney, thyroid, red marrow (leukemia), as well
as residual impacts on all remaining cancer sites combined.
There are substantial uncertainties associated with the risk
coefficients in FGR-13 (EPA 1999e): researchers estimate that some of
the coefficients may change by a factor of more than 10 if plausible
alternative models are used to predict risks. While the report does not
bound the uncertainty for all radionuclides, it estimates that the
central-tendency risk coefficients for uranium-234 and radium-226 may
change by a factor of seven depending on the models employed to estimate

[[Page 76736]]

risk.\13\ Ranges that reflect uncertainty and variability in the risk
coefficients have been used to conduct a sensitivity analysis of risk
reductions and benefits, the results of which are reported in Economics
Analysis (USEPA 2000g).
---------------------------------------------------------------------------

\13\ Table 2.4, Uncertainty Categories for Selected Risk
Coefficients. Federal Guidance Report 13 (1999).
---------------------------------------------------------------------------

Since the available occurrence data do not provide information on
the contribution of individual radionuclides or isotopes to the total
activities of gross alpha or uranium, there is uncertainty involved in
the assumptions about isotopic ratios. These and other uncertainties
related to occurrence information (e.g., uncertainty in extending the
NIRS database results to the national level) also contribute to
uncertainty in the estimates of impacts. Other inputs that were used in
the sensitivity analysis of risk reductions and benefits are the age-
and gender-dependent distributions of water ingestion, which are used
in estimating lifetime exposure, and the credible range for the ``value
of a statistical life.''
b. Uncertainty in Compliance Cost Estimates
Regarding uncertainty in the compliance cost estimates, these
estimates assume that most systems will install treatment to comply
with the MCLs, while recent research suggests that water systems
usually select compliance options like blending (combining water from
multiple sources), developing new ground water wells, and purchasing
water (USEPA 2000g). As discussed in the NODA, preliminary data (202
compliance actions from 14 States) on nitrate violations suggest that
only around a quarter (25%) of those systems taking action in response
to a nitrate violation installed treatment, while roughly a third
developed a new well or wells. The remainder either modified the
existing operations (10-15%), blended (15%), or purchased water (15-
20%). Similar data for radium violations from the State of Illinois (77
compliance actions) indicate that around a quarter of systems taking
action installed treatment, while the majority (50-55%) purchased
water, with the remainder (20-25%) either installing a new well,
blending, or stopping production from the contaminated well or wells.
EPA will continue to gather information regarding the prevalence of
treatment versus non-treatment options for compliance for other
contaminants. At this time, this data is considered preliminary and
will be used for comparisons only.
To evaluate the potential variability in the compliance cost
estimates, EPA has performed a sensitivity analysis for uncertainties
in the decision tree by varying the assumed percentages for the modeled
compliance options. Since per system costs are much higher for very
large systems, the assumptions used in the large water system size
categories can be expected to dominate the variability in national
costs. The sensitivity analysis results are reported in the Economic
Analysis (USEPA 2000g).
4. Major Comments
Following is a summary of the major comments received on the
analysis of costs and benefits for the finalization of the
radionuclides rule.
a. Retention of radium-226/-228 MCL of 5 pCi/L: Several commenters
suggested that the costs and benefits of compliance with the existing
radium-226/-228 MCL should be included in the analysis of the costs and
benefits of the finalization of today's rule, because ``systems
currently in non-compliance with the combined radium MCL are in that
situation because of EPA's proposed rule changes in 1991.'' EPA
disagrees with this comment since all of MCLs for the currently
regulated radionuclides, including radium-226/-228 have been fully
enforceable since 1976. While some may argue that the radionuclides
rules were ``National Interim Primary Drinking Water Regulations''
(NIPDWRs) between 1976 and 1986, NIPDWRs were fully enforceable. In
addition, six years elapsed between the re-authorization of the Safe
Drinking Water Act (1986), which finalized all NIPDWRs, and the 1991
proposal. Given the fact that 25 years have elapsed since this MCL
became an enforceable standard, EPA believes that it is appropriate to
consider only the costs and benefits of the changes that are being made
in the current standards. In view of the fact that 25 years have
elapsed since this MCL became an enforceable standard, EPA believes
that is appropriate to consider only the costs and benefits of the
changes that are made to the current radium standards as a cost of
today's rule. EPA further believes that any costs incurred by
facilities that are required to comply with the 1976 rule represent
deferred costs that those facilities elected not to expend until now.\14\
---------------------------------------------------------------------------

\14\ It is difficult to estimate these costs due to recent
efforts by many CWSs to comply with the current radium rule,
however, we would expect approximately 200-400 systems would spend
in the range of $18-36 million annually to comply with the current
standard. (Low estimate in range is based on recent SDWIS data; high
estimate is based on 1984 NIRS occurrence database.)
---------------------------------------------------------------------------

b. Cost/Benefit Analysis Requirements: One commenter suggested that
the analysis of costs and benefits, as presented in the Notice of Data
Availability (USEPA 2000e) omitted some information required under
section 1412(b)(4)(C) of the 1996 SDWA. EPA disagrees with this
comment. All of the required information relevant to the analysis of
costs and benefits for the options considered are found in the draft
Health Risk Reduction and Cost Analysis (HRRCA, USEPA 2000f), which was
announced by and described in the NODA. In the HRRCA, EPA did meet the
requirements of the Safe Drinking Water Act for performing analyses of
costs and benefits. For compliance with each regulatory option being
considered, EPA updated the analysis supporting the 1991 radionuclides
proposal, including estimates of quantifiable and non-quantifiable
health risk reduction benefits, quantifiable and non-quantifiable
health risk reduction benefits likely to occur from reductions in co-
occurring contaminants (excluding those associated with compliance with
other proposed or promulgated regulations), quantifiable and non-
quantifiable costs, the incremental costs and benefits for the uranium
options, the effects of the contaminant on the general population and
on sensitive groups within the population (e.g., children), and other
relevant factors. In addition to the HRRCA, EPA is supporting today's
final actions with a Economic Analysis (USEPA 2000g) that builds on the
HRRCA, including some changes made in response to comments received.
c. Cumulative Affordability: Several commenters suggested that EPA
consider the cumulative impact of its regulations on the affordability
of water service, as opposed to looking at affordability one regulation
at a time. EPA agrees that it would be best to look at ``cumulative
affordability,'' since this is the only realistic indicator of
affordability. For this reason, EPA includes a ``water bill baseline''
in its affordability assessments, which includes cumulative impacts
from existing regulations. When a rule is promulgated, the water bill
baseline increases and the estimate of affordability decreases, the
details of which depend on the percentages of systems impacted and the
estimates of the annual per household costs associated with the
regulation. The affordability assessment supporting the uranium small
systems compliance

[[Page 76737]]

technology list is based on the current baseline, which is described in
``Variance Technology Findings for Contaminants Regulated Before
1996'', which can be downloaded at ``http://www.epa.gov/OGWDW/standard/
varfd.pdf.'' As future rules are promulgated that impact small water
systems (including this one), this baseline will be revised.
d. Disposal costs: One commenter suggested that EPA ``did not
adequately address the disposal of waste stream residuals'' in the NODA
and that waste disposal costs are a ``significant factor'' in
estimating costs. EPA agrees that waste disposal considerations are
very important when considering the implementation of this rule. Since
the only MCL that EPA is finalizing today is the uranium MCL (the
others are existing regulations), this is the only MCL that could be
impacted by this consideration. In estimating the compliance costs for
today's actions, EPA did include waste disposal costs in its estimate
of treatment costs, including estimated waste-related capital costs,
operations and maintenance costs, and residuals disposal. EPA believes
that its estimate of residuals disposal are adequate and are based on
the best available information.
e. Discounting of Costs and Benefits: One commenter stated that it
is ``appropriate and standard practice to ensure that costs and
benefits be evaluated on the same basis to avoid apples and oranges
comparison,'' further stating that EPA should discount both or neither.
EPA agrees that costs and benefits should be evaluated in such a way
that they can be compared.
One approach to accomplish this is to annualize the costs and
benefits of the regulation. In such instances, the capital costs, paid
up front, need to be spread out across the life of the equipment. To do
that, one needs to reflect the time value of resources. The analyst
must ask the question: What is the annual payment that could finance
the capital investment? Such a calculation would reflect the social
discount rate. Annual operations and maintenance (O&M) costs would not
have to be annualized, since these costs are assumed to be accrued on a
continual basis each year.
Ideally, the analysis would also annualize the benefits using the
same techniques. As noted previously, we have not made any such
adjustments to the benefits associated with today's rule for uranium
since the principal benefits are non-quantifiable (avoidance of kidney
toxicity due to reductions in exposure to uranium). We do not believe
that adjustments to these benefits estimates for either timing or
income growth would materially affect our benefits assessment or
decisions resulting from overall consideration of the benefits and
costs of the regulatory standard.
f. Use of MCLs for Ground Water Protection Needs to be Evaluated as
Part of this Rulemaking: One commenter stated that, since linkages are
made between drinking water standards and ``clean-up standards'' for
radioactively contaminated sites, the costs and benefits of applying
drinking water standards to clean-up efforts should be evaluated as
part of this rulemaking. EPA disagrees that clean-up costs and benefits
should be used to influence the setting of drinking water MCLs. EPA
does, however, agree that cross-program costs and benefits should be
considered when appropriate. In this case, it is inappropriate to
consider clean-up and ground water protection costs since MCLs are set
specifically and solely with drinking water exposures in mind. If
another program or Agency applies these MCLs for other purposes (e.g.,
clean-up standards), then the costs and benefits of that application
should be considered when evaluating that application.

V. Other Required Analyses and Consultations

A. Regulatory Flexibility Act (RFA)

The RFA, as amended by the Small Business Regulatory Enforcement
Fairness Act of 1996 (SBREFA), 5 USC 601 et seq., generally requires an
agency to prepare a regulatory flexibility analysis of any rule subject
to notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
The RFA provides default definitions for each type of small entity.
It also authorizes an agency to use alternative definitions for each
category of small entity, ``which are appropriate to the activities of
the agency'' after proposing the alternative definition(s) in the
Federal Register and taking comment. 5 U.S.C. sec. 601(3)-(5). In
addition to the above, to establish an alternative small business
definition, agencies must consult with SBA's Chief Counsel for Advocacy.
For purposes of assessing the impacts of today's rule on small
entities, EPA considered small entities to be CWSs serving fewer than
10,000 persons. This is the cut-off level specified by Congress in the
1996 Amendments to the Safe Drinking Water Act for small system
flexibility provisions. Because this definition does not correspond to
the definitions of ``small'' for small businesses, governments, and
non-profit organizations, EPA requested comment on an alternative
definition of ``small entity'' in the preamble to the proposed Consumer
Confidence Report (CCR) regulation (63 FR 7620, February 13, 1998).
Comments showed that stakeholders support the proposed alternative
definition. EPA also consulted with the Small Business Administration's
Office of Advocacy on the definition as it relates to small business
analysis. In the preamble to the final CCR regulation (63 FR 4511,
August 19, 1998), EPA expressed its intention to use this alternative
definition for regulatory flexibility assessments under the RFA for all
drinking water regulations and has thus used it in this final rulemaking.
In accordance with section 603 of the RFA, EPA prepared an initial
regulatory flexibility analysis (IRFA) for the 1991 proposed rule (see
56 FR 33050). Since the proposed rule (July 18, 1991) pre-dated the
1996 Amendments to the RFA, EPA did not convene a Small Business
Advocacy Review Panel for this rule.
We also prepared a final regulatory flexibility analysis (FRFA) for
today's final rule. The FRFA addresses the issues raised by public
comments on the IRFA, which was part of the proposal of this rule. The
FRFA is available for review in the docket and is summarized below.
The RFA requires EPA to include the following when completing an FRFA:
(1) A succinct statement of the need for, and objectives of the rule;
(2) A summary of the significant issues raised by the public
comments on the IRFA, and a summary of the assessment of those issues,
and a statement of any changes made to the proposed rule as a result of
those comments;
(3) A description of the types and number of small entities to
which the rule will apply and the impact they will experience, or an
explanation why no estimate is available;
(4) A description of reporting, record keeping, and other
compliance requirements of the rule, including an estimate of the
classes of small entities which will be subject to the rule and the
type of professional skills necessary for preparation of reports or
records; and
(5) A description of the steps the Agency has taken to minimize the
significant impact on small entities consistent with the stated
objectives of

[[Page 76738]]

the applicable statutes, including a statement of the factual, policy,
and legal reasons why we selected the chosen alternative in the final
rule and why the other significant alternatives to the rule were rejected.
EPA has considered and addressed all of the requirements. The
following is a summary of the FRFA. The need for and objectives for the
rule are discussed in sections I.A, I.B, I.C and II.A of this preamble.
Requirements ``2'' through ``4'' are addressed in the subsections that
follow. The fifth requirement is discussed in sections I.D and I.J.,
which provide information about steps EPA has taken that will lessen
impacts on small systems, including: (1) The selection of the less
stringent uranium MCL, (2) overall reduced monitoring frequencies for
systems with radionuclides levels less than the MCL, (3) allowance of
grandfathering of data and State monitoring discretion for determining
initial monitoring baseline, and (4) exclusion of NTNCWS from the
regulation. Sections I.C. and I.B provide the rationale for the
retention of the MCLs for radium-226 and -228, gross alpha, and photon/
beta emitters.
The significant issues raised in public comments were the high cost
of compliance for small systems and high cumulative costs for water
contaminant testing. EPA understands these concerns and has made
several changes to the proposed rule that will reduce cost impacts to
small systems. In addition, commenters disagreed with the proposal to
include NTNC water systems in the rule. Based on several factors,
including these comments and the analyses of risks faced by NTNC
customers, risk reductions, benefits, and costs, EPA has decided that
additional future analyses and reevaluation, together with any new data
that can be obtained is needed before regulating radionuclides at NTNC
drinking water systems (see section I.D.8. for further discussion).
This information will be collected and future regulatory action will be
assessed under the regulatory review process. A complete summary of
comments received and EPA's responses can be obtained from the docket
(USEPA 2000a).
For many small entities, today's final rule will reduce long-term
monitoring costs because the rule provides for less frequent follow-up
monitoring (relative to the 1976 rule) for systems if they have
radionuclides levels (e.g., gross alpha and radium-226 and -228) below
the MCLs (most small systems). For example, under the 1976 rule, a
system with a gross alpha level less than the MCL but greater than \1/
2\ MCL is required to monitor four times in a four year period. The
revised monitoring scheme will allow this system to reduce the
monitoring frequency to one sample every three years or less. In
addition, EPA is giving States discretion in using historical
monitoring data (grandfathering) to determine the initial monitoring
baseline for systems. Therefore, systems with sufficient data may not
be required to take four quarterly samples for the initial monitoring
period and may immediately begin reduced monitoring (e.g., one sample
per three years, six years, or nine years) after the rule is effective
(e.g., three years after the rule is promulgated). See sections I.D
``How has this new information impacted the regulatory decisions being
promulgated today?'' and I.J ``Where and how often must a water system
test for radionuclides?'' for additional information about monitoring.
A small percentage (1.5%) of systems are expected to exceed the radium-
226 and-228 and uranium MCLs and will be required to take action to
come into compliance.
The number of small entities subject to today's rule is shown in
Table V-1.

Table V-1.--Summary of Analysis Results
From the ``Economic Analysis of the Radionuclides NPDWR'' (USEPA 2000g)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Ground water systems Surface water systems
--------------------------------------------------------------------------------------------------------------------------------
Combined radium loophole Uranium (20g/L) Uranium (40 g/ Uranium (20 g/ Uranium (40 g/
Community water system size class (25 to 10,00) ---------------------------------------------------- L) L) L)
----------------------------------------------------------------
Number of Cost/ Number of Cost/ Number of Cost/ Number of Cost/ Number of Cost/
systems Revenue systems Revenue systems Revenue systems Revenue systems Revenue
---------------------------------------------------------------------\1\-----------------------\1\-----------------------\1\-----------------------\1\-----------------------\1\---
Total............................................ 270-310 \2\ 1-2 820-900 \2\ 1-3 300-400 \2\ 1-3 10-40 \2\ 1-3 0-20 \2\ 0-3
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ As reported in the economic analysis support document (USEPA 2000g), the revenue portion of the cost per revenue estimates are based on data collected the 1992 Census of
Governments. The Agency then estimated average revenues for small governments.
The reported ranges represent results using the directly proportional approach followed by results using the lognormal distribution approach.
``0'' indicates that no systems in this category are expected to be out of compliance with the MCL.
Revenue estimates are taken from Exhibit 6-3 of the economic analysis support document (USEPA 2000g).
See Appendix G of the economic analysis support document (USEPA 2000g) for information regarding the number of affected for the 25 to 10,000 size class and the associated costs.
Detail does not add to totals due to rounding.
\2\ Percent.

Small systems are also required to provide information in the
Consumer Confidence Report or other public notification if the system
exceeds one of the MCLs. As is the case for other contaminants,
required information on radionuclides levels must be provided by
affected systems and is not considered to be confidential. The
professional skills necessary for preparing reports are the same skill
level required by small systems for current reporting and monitoring
requirements for other drinking water standards.
In addition to the public comments on the proposal, the Agency
considered comments received through an outreach process that obtained
input from small entities, including a Stakeholders meeting, Tribal
consultations, and other consultations. After considering all the input
from stakeholders as well as its own analyses, the Agency has included
several measures in today's rule that should reduce the burden on small
drinking water systems: (1) A revised monitoring scheme with long-term
monitoring reduction for most small systems; (2) State discretion for
grandfathering existing monitoring data; (3) the decision not to
regulate non-transient, non-community water systems, which are
generally very small water systems; and (4) the selection of a uranium
MCL that is less stringent than the 1991 proposed feasible level. The
uranium MCL is still protective of public health with an adequate margin

[[Page 76739]]

of safety, but will impact fewer small systems, reducing the number of
systems that may face waste disposal issues, and increasing the
likelihood that non-treatment options for achieving compliance may be
used. These items are discussed in more detail in sections I.D and I.J.
EPA also is preparing a small entity compliance guide to help small
entities comply with this rule. Small entities will be able to access a
copy of this guide at: http://www.epa.gov/sbrefa/ (to be available
within 60 days of the publication of the rule in the Federal Register).

B. Paperwork Reduction Act

The Office of Management and Budget (OMB) has approved the
information collection requirements contained in this rule under the
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and
has assigned OMB control number--2040-0228
Under this rule, respondents to the monitoring, reporting, and
recordkeeping requirements include the owners and operators of
community water systems and State officials that must report data to
the Agency. Monitoring for radium-228, uranium, and beta and photon
emitters will be required at each entry point to the distribution
system under the final radionuclides rule. States will have discretion
in grandfathering existing data for determining initial monitoring
baselines for the currently regulated contaminants, combined radium-
226/-228, gross alpha particle activity, and beta particle and photon
radioactivity.
EPA has estimated the burden associated with the specific
information collection, record keeping and reporting requirements of
the proposed rule in the accompanying Information Collection Request
(ICR). The ICR for today's final rule compares the current requirements
to the revised requirements for information collection, reporting and
record-keeping. There are several activities that the State and the
CWSs must perform in preparing to comply with the revised Radionuclides
Rule. Start-up activities include reading the final rule to become
familiar with the requirements and training staff to perform the
required activities.
For PWSs, the number of hours required to perform each activity may
vary by system size. This rule only applies to community water systems.
As shown in Table V-2, there are approximately 53,121 CWSs and 56
States and territories considered in this ICR (a total of 53,177
respondents). During the first three years after promulgation of this
rule, the average burden hours per respondent per year is estimated to
be 6 hours for PWSs and 115 hours for States. During this period, the
total burden hour per year for the approximately 53,177 respondents
covered by this rule is estimated to be 342,873 hours to prepare to
comply with this revised Radionuclide Rule. There are no new
monitoring, record-keeping, reporting or equipment costs for CWSs
during the first three-year period, hence no responses are expected
from the CWSs. The average number of responses for the States is
expected to be 37 per year during the first three year period. Total
annual labor costs during this first 3 year period are expected to be
about $10 million per year for CWS.

Table V-2.--Average Burden, Respondents, and Responses During the Three-Year ICR Approval Period
----------------------------------------------------------------------------------------------------------------
Total (each
CWSs States year)
----------------------------------------------------------------------------------------------------------------
Average Burden Hours per Year................................... 336,433 6,440 342,873
Average Respondents per Year.................................... 53,121 56 53,177
Average Burden Hours per Respondent per Year.................... 6 115 121
Average Responses per Year...................................... \1\ 0 33 33
Average Burden Hours per Response per Year...................... \1\ 0 17 17
Average Responses per Respondent per Year....................... \1\ 0 \2\ .66 .66
----------------------------------------------------------------------------------------------------------------
\1\ Preparation only.
\2\ Two over 3-year period.

Table V-3.--Summary of Burden and Costs for the Radionuclides Rule for the ICR Approval Period
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of Number of Total annual Total annual
Respondent Category respondents responses burden labor costs Total annual Total annual
annually annually (hours) ($ dollars) capital cost O&M cost
--------------------------------------------------------------------------------------------------------------------------------------------------------
CWSs.................................................... 53,121 (\1\) 336,433 $9,925,042 0 0
States.................................................. 56 \2\ 37 (2 per 6,440 247,905 0 0
respondent
over 3 year
period)
-----------------------------------------------------------------------------------------------
Total............................................... 53,177 33 342,873 10,172,947 0 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Preparation only.
\2\ Two per respondent over 3-year period.

Three years after the promulgation date, community water systems
will begin collecting mandatory monitoring data as described earlier in
this section. As reported in the ICR (using a 7% discount rate over a
23 year period), EPA estimates that today's revisions to monitoring
will result in a national annual monitoring, reporting and record
keeping burden of $ 4.85 million (25,197 hours) for all CWSs and an
average annual programmatic burden of $63,723 (4,170 hours) for States
(total for all 56 jurisdictions) over the first 23 years after
promulgation of this rule (see Table V-4).

[[Page 76740]]

Table V-4.--Summary of Burden and Costs for the Radionuclides Rule for the Post-ICR Approval Period
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of Number of Total annual Total annual
Respondent category respondents responses burden Total annual Total annual O&M cost
annually annually (hours) labor costs capital cost (monitoring)
--------------------------------------------------------------------------------------------------------------------------------------------------------
CWSs.................................................... 53,121 50,394 25,197 $537,574 0 $4,855,439
States.................................................. 56 224 4,170 63,723 0 63,723
-----------------------------------------------------------------------------------------------
Total............................................... 53,177 50,618 29,367 601,297 0 4,919,162
--------------------------------------------------------------------------------------------------------------------------------------------------------

Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing procedures to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations are listed in 40 CFR part 9 and 48 CFR chapter 15. EPA is
amending the table in 40 CFR part 9 of the currently approved ICR
control numbers issued by OMB for various regulations to list the
information requirements contained in this final rule.

C. Unfunded Mandates Reform Act

1. Summary of UMRA Requirements
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub.L.
104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector. Under UMRA section 202, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to State, local, and tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule, for which a written
statement is needed, section 205 of the UMRA generally requires EPA to
identify and consider a reasonable number of regulatory alternatives
and adopt the least costly, most cost-effective or least burdensome
alternative that achieves the objectives of the rule. The provisions of
section 205 do not apply when they are inconsistent with applicable
law. Moreover, section 205 allows EPA to adopt an alternative other
than the least costly, most cost-effective or least burdensome
alternative if the Administrator publishes with the final rule an
explanation of why that alternative was not adopted.
Before EPA establishes any regulatory requirements that may
significantly or uniquely affect small governments, including tribal
governments, it must have developed, under section 203 of the UMRA, a
small government agency plan. The plan must provide for notifying
potentially affected small governments, enabling officials of affected
small governments to have meaningful and timely input in the
development of EPA regulatory proposals with significant Federal
intergovernmental mandates and informing, educating, and advising small
governments on compliance with the regulatory requirements.
EPA has determined that this rule does not contain a Federal
mandate that may result in expenditures of $100 million or more for
State, local, and tribal governments, in the aggregate, or the private
sector in any one year. The estimated total annual compliance costs of
the final rule is 83 million (See section IV. Economic Analyses for
additional information). Thus, today's rule is not subject to the
requirements of sections 202 and 205 of the UMRA. This rule will
establish requirements that affect small community water systems. EPA
has determined that this rule may contain regulatory requirements that
significantly or uniquely affect small governments. As described in
part A of this section, EPA has provided all public water systems
(including small systems) with opportunities to provide input into the
development of this rule and to be informed about the requirements for
compliance.

D. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), (Pub. L. 104-113, section 12(d), 15 U.S.C. 272
note), directs EPA to use voluntary consensus standards in its
regulatory activities unless to do so would be inconsistent with
applicable law or otherwise impractical. Voluntary consensus standards
are technical standards (e.g., material specifications, test methods,
sampling procedures, business practices) that are developed or adopted
by voluntary consensus standard bodies. The NTTAA directs EPA to
provide to Congress, through OMB, explanations when the Agency decides
not to use available and applicable voluntary consensus standards.
Today's rule does not establish any technical standards, thus,
NTTAA does not apply to this rule. It should be noted, however, that
systems complying with this rule need to use previously approved
technical standards already included in Sec. 141.25. Currently, a total
of 89 radiochemical methods are approved for compliance monitoring of
radionuclides in drinking water. Of these methods, twenty-four (24) are
approved by the Standard Methods Committee and are described in the
``Standard Methods for the Examination of Waste and Wastewater (13th,
17th, 18th, and 19th editions),'' which was prepared and published by
the American Public Health Association. In addition, twelve of the
approved radiochemistry methods are from the American Society for
Testing and Materials (ASTM) and are described in the Annual Book of
ASTM Standards. These methods and their references are provided in
Table I-8 (shown in section I of this preamble).

E. Executive Order 12866: Regulatory Planning and Review

Under Executive Order 12866, [58 FR 51735 (October 4, 1993)] the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant

[[Page 76741]]

regulatory action'' as one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.''
Pursuant to the terms of Executive Order 12866, it has been
determined that this rule is a ``significant regulatory action.'' As
such, this action was submitted to OMB for review. Changes made in
response to OMB suggestions or recommendations will be documented in
the public record.

F. Executive Order 12898: Environmental Justice

Executive Order 12898 ``Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations,'' (59 FR
7629, February 16, 1994) establishes a Federal policy for incorporating
environmental justice into Federal agency missions by directing
agencies to identify and address disproportionately high and adverse
human health or environmental effects of its programs, policies, and
activities on minority and low-income populations. The Agency has
considered environmental justice-related issues concerning the
potential impacts of this action and has consulted with minority and
low-income stakeholders by convening a stakeholder meeting via video
conference specifically to address environmental justice issues.
As part of EPA's responsibilities to comply with E.O. 12898, the
Agency held a stakeholder meeting via video conference on March 12,
1998, to highlight components of pending drinking water regulations and
how they may impact sensitive sub-populations, minority populations,
and low-income populations. Topics discussed included treatment
techniques, costs and benefits, data quality, health effects, and the
regulatory process. Participants included national, State, tribal,
municipal, and individual stakeholders. EPA conducted the meeting by
video conference call between eleven cities. This meeting was a
continuation of stakeholder meetings that started in 1995 to obtain
input on the Agency's Drinking Water programs. The major objectives for
the 1998 meeting were:
(1) Solicit ideas from Environmental Justice (EJ) stakeholders on
known issues concerning current drinking water regulatory efforts;
(2) Identify key issues of concern to EJ stakeholders; and
(3) Receive suggestions from EJ stakeholders concerning ways to
increase representation of EJ communities in OGWDW regulatory efforts.
In addition, EPA developed a plain-English guide specifically for
this meeting to assist stakeholders in understanding the multiple and
sometimes complex issues surrounding drinking water regulations. A
meeting summary for the March 12, 1998 Environmental Justice
stakeholders meeting (USEPA 1998J) is available in the public docket
for this final rulemaking.
The radionuclides rule applies to all community water systems,
which will provide equal health protection for all minority and low-
income populations served by systems regulated under this rule from
exposure to radionuclides.

G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

Executive Order 13045: ``Protection of Children from Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies
to any rule that: (1) Was initiated after April 21, 1997, or for which
a Notice of Proposed Rulemaking was published after April 21, 1998; (2)
is determined to be ``economically significant'' as defined under E.O.
12866, and (3) concerns an environmental health or safety risk that EPA
has reason to believe may have a disproportionate effect on children.
If the regulatory action meets all three criteria, the Agency must
evaluate the environmental health or safety effects of the planned rule
on children, and explain why the planned regulation is preferable to
other potentially effective and reasonably feasible alternatives
considered by the Agency.
This final rule is not subject to the Executive Order because EPA
published a notice of proposed rulemaking before April 21, 1998.
However, EPA's policy since November 1, 1995 is to consistently and
explicitly consider risks to infants and children in all risk
assessments generated during its decision making process including the
setting of standards to protect public health and the environment.
Today's action primarily involves retaining the current MCLs for
the regulated radionuclides, rather than adopting the less stringent
1991 proposed MCLs for the regulated radionuclides. In addition, an MCL
for uranium, currently unregulated, is promulgated in today's rule.
Since today's rule involves the decision to retain the more stringent
current MCLs and to adopt a uranium MCL that is protective of both
kidney toxicity and radiological carcinogenicity, today's action is
consistent with greater protection of children's health.
The cancer risks estimated and presented in today's final rule
explicitly account for differential cancer risks to children. In the
case of uranium kidney toxicity, there is no information that suggests
that children are a sensitive subpopulation. However, as discussed in
the Notice of Data Availability (USEPA 2000e), the Agency does have
reason to believe that radionuclides in drinking water present higher
unit risks to children than to adults, since there is evidence that
children are more sensitive to radiation than adults. Because of this,
we have explicitly considered the risks to children in evaluating the
lifetime risks associated with the current MCLs and 1991 proposed MCLs.
In other words, the lifetime risks that are reported for each MCL are
integrated over the entire lifetime of the individual and include the
risks incurred during childhood.
In more detail, the per unit dose risk coefficients used to
estimate lifetime risks are age-specific and organ-specific and are
used in a lifetime risk model that applies the appropriate age-specific
sensitivities throughout the calculation. The model also includes age-
specific changes in organ mass and metabolism, which further
incorporates age-specific effects pertinent to age sensitivity. The
risk estimate at any age is the best estimate of risk for an individual
of that age, so the summation of these age-specific risk estimates over
all ages is best estimate of the lifetime risk for an individual. In
developing the lifetime risks, the model calculates the risks over an
age distribution for a stationary population to simulate the lifetime
risk of an individual. The model also accounts for competing causes of
death and age-specific survival rates. These adjustments make the
lifetime risk estimate more realistic. At the same time, consumption
rates of food, water and air are different between adults and children.
The lifetime risk estimates for radionuclides in water use age-specific
water intake rates derived from average

[[Page 76742]]

national consumption rates when calculating the risk per unit intake.
While radiation protection organizations have developed the concept
of committed dose, the dose to an organ or tissue from time of intake
to end of life, there is no equivalent for risk. If we define
``committed risk'' as the lifetime risk from a given intake, then it
will be easier to compare the risks of intakes at different times of
life. In Table V-5, the ``committed risk'' is given for 5 isotopes and
5 periods of life and continuous lifetime exposure. If the radionuclide
concentration in the water is kept constant, the fraction of the
lifetime risk committed during any age interval will also remain
constant. Unless the intake is restricted in an age-specific manner,
the fraction of the lifetime risk contributed by any age interval is a
constant.

Table V-5.--Lifetime Risks and Fractions of Lifetime Risk Per Age Group
----------------------------------------------------------------------------------------------------------------
Age (yrs) 0-6 6-18 18-30 30-70 70-110 0-110
----------------------------------------------------------------------------------------------------------------
Lifetime risk for intake of water containing 1 Bq/L during several different age intervals
----------------------------------------------------------------------------------------------------------------
Ra-224........................................ 2.3e-05 3.3e-05 1.1e-05 1.5e-05 9.8e-07 8.4e-05
Ra-226........................................ 2.9e-05 8.6e-05 5.0e-05 5.1e-05 2.9e-06 2.2e-04
Ra-228........................................ 1.1e-04 2.6e-04 1.2e-04 1.1e-04 5.1e-06 6.1e-04
U-238......................................... 6.7e-06 1.2e-05 6.1e-06 9.8e-06 3.7e-07 3.4e-05
H-3........................................... 3.9e-09 8.5e-09 6.2e-09 9.6e-09 6.7e-10 2.9e-08
----------------------------------------------------------------------------------------------------------------
Percentage of lifetime risk committed for water intake during the age interval
----------------------------------------------------------------------------------------------------------------
Ra-224........................................ 28 40 13 18 1 100
Ra-226........................................ 13 39 23 23 1 100
Ra-228........................................ 17 43 20 19 1 100
U-238......................................... 19 33 18 28 1 100
H-3........................................... 13 29 21 33 2 100
----------------------------------------------------------------------------------------------------------------

In summary, today's decision to retain the current more stringent
MCLs for radionuclides and to establish an MCL for uranium in drinking
water is consistent with the protection of children's health. In making
this decision, EPA evaluated the lifetime radiogenic cancer risks
associated with the current and final MCLs, which are based on age-
specific cancer risk models that explicitly consider children's higher
per unit dose risks.

H. Executive Order 13084: Consultation and Coordination With Indian
Tribal Governments

Under Executive Order 13084, EPA may not issue a regulation that is
not required by statute if it significantly or uniquely affects the
communities of Indian tribal governments and imposes substantial direct
compliance costs on those communities, unless the Federal government
provides the funds necessary to pay the direct compliance costs
incurred by the tribal governments or if EPA consults with those
governments. If EPA complies by consulting, Executive Order 13084
requires EPA to provide to the Office of Management and Budget, in a
separately identified section of the preamble to the rule, a
description of the extent of EPA's prior consultation with
representatives of affected tribal governments, a summary of the nature
of their concerns, and a statement supporting the need to issue the
regulation. In addition, Executive Order 13084 requires EPA to develop
an effective process permitting elected officials and other
representatives of Indian tribal governments ``to provide meaningful
and timely input in the development of regulatory policies on matters
that significantly or uniquely affect their communities.''
EPA does not believe that today's rule significantly or uniquely
affect the communities of Indian tribal governments nor does it impose
substantial direct compliance costs on these communities. The
provisions of today's rules apply to all community water systems.
Tribal governments may be owners or operators of such systems, however,
nothing in today's provisions uniquely affects them. EPA believes that
the final rule will not significantly burdens most Tribal systems, and
in some cases, will be less burdensome than the current radionuclides
rule. Accordingly, the requirements of section 3(b) of Executive Order
13084 do not apply to this rule.
Nonetheless, EPA did inform and involve Tribal governments in the
rulemaking process. EPA staff attended the 16th Annual Consumer
Conference of the National Indian Health Board on October 6-8, 1998 in
Anchorage, Alaska. Over nine hundred attendees representing Tribes from
across the country were in attendance. During the conference, EPA
conducted two workshops for meeting participants. The objectives of the
workshops were to present an overview of EPA's drinking water program,
solicit comments on key issues of potential interest in upcoming
drinking water regulations, and to solicit advice in identifying an
effective consultative process with Tribes for the future.
EPA, in conjunction with the Inter Tribal Council of Arizona
(ITCA), also convened a Tribal consultation meeting on February 24-25,
1999, in Las Vegas, Nevada to discuss ways to involve Tribal
representatives, both Tribal council members and tribal water utility
operators, in the stakeholder process. Approximately twenty-five
representatives from a diverse group of Tribes attended the two-day
meeting. Meeting participants included representatives from the
following Tribes: Cherokee Nation, Nezperce Tribe, Jicarilla Apache
Tribe, Blackfeet Tribe, Seminole Tribe of Florida, Hopi Tribe, Cheyenne
River Sioux Tribe, Menominee Indian Tribe, Tulalip Tribes, Mississippi
Band of Choctaw Indians, Narragansett Indian Tribe, and Yakama Nation.
The major meeting objectives were to:
(1) Identify key issues of concern to Tribal representatives;
(2) Solicit input on issues concerning current OGWDW regulatory efforts;
(3) Solicit input and information that should be included in
support of future drinking water regulations; and
(4) Provide an effective format for Tribal involvement in EPA's
regulatory development process.
EPA staff also provided an overview on the forthcoming
radionuclides rule at the meeting. The presentation included the health
concerns associated with radionuclides, EPA's current position

[[Page 76743]]

on radionuclides in drinking water, and specific issues for Tribes. The
following questions were posed to the Tribal representatives to begin
discussion on radionuclides in drinking water:
(1) What are the current radionuclides levels in your water systems?
(2) Are you treating for radionuclides if they exceed the MCL? Is
it effective and affordable?
(3) What are Tribal water systems affordability issues in regard to
radionuclides?
(4) Would in home treatment units be an acceptable alternative to
central treatment?
(5) What level of monitoring is reasonable?
The summary for the February 24-25, 1999 meeting was sent to all
565 Federally recognized Tribes in the United States.
EPA also conducted a series of workshops at the Annual Conference
of the National Tribal Environmental Council which was held on May 18-
20, 1999 in Eureka, California. Representatives from over 50 Tribes
attended all, or part, of these sessions. The objectives of the
workshops were to provide an overview of forthcoming EPA regulations
affecting water systems; discuss changes to operator certification
requirements; discuss funding for Tribal water systems; and to discuss
innovative approaches to regulatory cost reduction. Meeting summaries
for EPA's Tribal consultations are available in the public docket for
this rulemaking (USEPA 1999c, USEPA 1999d).

I. Executive Order 13132

Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'are defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
This final rule does not have federalism implications. It will not
have substantial direct effects on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government,
as specified in Executive Order 13132. Thus, Executive Order 13132 does
not apply to this rule
Although Executive Order 13132 does not apply to this rule, EPA did
consult with representatives of State and local elected officials in
the process of developing this final regulation. On May 30, 2000, EPA
held a one-day meeting in Washington, DC with representatives of
elected State and local officials to discuss how upcoming drinking
water regulations may affect State, county, and local governments. The
rules discussed were: Arsenic, Radon, Radionuclides, Long Term 1
Enhanced Surface Water Treatment and Filter Backwash Rule, and the
Ground Water Rule. EPA invited associations which represent elected
officials, including National Governors' Association (NGA), National
League of Cities (NLC), Council of State Governments (CSG), U.S.
Conference of Mayors, International City/County Management Association
(ICMA), National Association of Counties (NACO), National Association
of Towns and Townships, and National Conference of State Legislators
(NCSL). EPA also invited the National Association of Attorneys General
(NAAG), the Association of State and Territorial Health Officials
(ASTHO), the Environmental Council of States (ECOS), and the Southern
Govenors' Association (SGO). With the invitation letter, EPA provided
an agenda and background information about the five upcoming drinking
water rules, including today's rule.
Ten representatives of elected officials participated in the one-
day meeting, which included State of Florida--Governor Bush's Office,
State of Ohio-Governor Taft's Office, NGA, NACO, NAAG, NLC, ECOS, ICMA,
SGO, and ASTHO. The meeting encompassed presentation and discussion
about each of the five rules. The purpose of the meeting was to:
Provide information about the five upcoming drinking water regulations;
Consult on the expected compliance and implementation
costs of these rules for State, county, and local governments; and
Gain a better understanding of State, county, and local
governments' and their elected officials' views.
Following the meeting, EPA sent the materials presented and
distributed at the meeting to the organizations that were not able to
attend, in order to provide them additional information about the
upcoming regulations. EPA has prepared a meeting summary which provides
in more detail the participants' concerns and questions regarding each
rule. This summary is available in the public docket supporting this
rulemaking (USEPA 2000c).
This meeting was not held sooner due to the relatively recently
signed Executive Order and the need to consider how to best comply with
its terms and conditions. Thus, many of the issues associated with
today's rulemaking were in relatively advanced stages of development by
the time of the May 30, 2000 meeting. Nevertheless, we endeavored to
accommodate each of the comments received from elected officials or
their representatives to the maximum extent possible, within the
constraints imposed by our statutory mandate to protect public health
through the promulgation of drinking water standards.
The principal concerns of these officials were the overall burden
of the rule and the potentially high costs of compliance with its
provisions. In particular, they expressed concerns about the
affordability for the rule for small systems and costs for disposal of
treatment residues that may be considered hazardous due to
radioactivity. In response, we took several steps to address these
particular concerns as well as actions in response to the generalized
concern about the overall burden of the rule.
EPA believes that today's regulatory action is necessary to reduce
kidney toxicity and cancer health risks from uranium, as well as to
maintain public health protection resulting from the current
radionuclide National Primary Drinking Water Regulations. The Agency
understands the officials' concerns about regulatory burden and have
addressed them in several ways. First, EPA selected a less stringent
MCL for uranium of 30 g/L by invoking the discretionary
authority for the Administrator to set an MCL less stringent than the
feasible level if the benefits of an MCL set at the feasible level
would not justify the costs (section 1412(b)(6)). As a result, fewer
water systems will be in violation of the uranium MCL, reducing the
number of systems that may face radioactive waste disposal issues, and
resulting in the ability of a higher percentage of water systems to use
non-treatment options for achieving compliance (e.g., new wells,
blending of water sources, modifying existing operations, etc.).
To further mitigate impacts on water systems and State drinking
water programs, EPA is allowing State discretion in grandfathering data
for determining initial monitoring frequency. Since the data
grandfathering plan will be a part of a State's primacy package, EPA
will have oversight over the data grandfathering process. EPA believes
that this approach provides flexibility for States to consider their

[[Page 76744]]

particular circumstances, while allowing EPA to ensure that goals are
met. Under this approach, many systems will be able to use existing
monitoring data to establish initial monitoring baselines, which will
be used to determine future monitoring frequency under the Standardized
Monitoring Framework. Water systems that do not have adequate data to
grandfather will be required to follow the requirements for new
monitoring. The details of these requirements can be found in part J of
section I, ``Where and how often must a water system test for
radionuclides?'' EPA expects that there will be overall reduced
monitoring burden in the long-term, with monitoring relief being
targeted towards those water systems that have low radionuclide levels.
Today's final rule will not apply to non-transient, non-community water
systems (e.g., schools, state parks, nursing homes), which are
primarily small ground water systems.
EPA will provide guidance to small water systems on complying with
today's rule. This will include information on monitoring, treatment
technology and other compliance options, including information on the
disposal of water treatment residuals. Regarding the cost of treatment,
EPA agrees that treatment technologies can be expensive for small water
systems. However, EPA expects that many small water systems will rely
on other compliance options, e.g., alternate source, purchasing water,
and point-of-use devices. In cases in which small water systems have no
other option and cannot afford to install treatment, they may apply to
the State for exemptions (see part M of section I, ``Can my water
system get a variance or an exemption?''), which gives them extra time.
An exemption is limited to three years after the otherwise applicable
compliance date, although extensions up to a total of six additional
years may be available to small systems under certain conditions. If a
water system has very high contaminant levels and no compliance options
other than treatment, the water system can apply for a variance, under
the requirements described in part M of section I. In addition, there
are various sources of funding for State and local governments,
including the Drinking Water State Revolving Fund, which is described
in part M of section I, ``What financial assistance is available for
complying with the rule?''

J. Consultation With the Science Advisory Board and the National
Drinking Water Advisory Council

In accordance with section 1412(d) and (e) of SDWA, EPA consulted
with the Science Advisory Board and National Drinking Water Advisory
Council and considered their comments in developing this rule. See the
OW Docket for additional information.

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This rule is not a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective December 8, 2003.

VI. References

NIH 2000a. ``Kidney Diseases: Publications On-Line.'' National
Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
June 2000. National Institutes of Health.
NIH 2000b. ``Proteinuria.'' National Kidney and Urologic Diseases
Information Clearinghouse. June 2000. National Institutes of Health.
NIH 2000c. ``Your Kidneys and How They Work.'' National Kidney and
Urologic Diseases Information Clearinghouse. June 2000. National
Institutes of Health.
USEPA 1991. ``Regulatory Impact Analysis of Proposed National
Primary Drinking Water Regulations for Radionuclides (Draft dated
June 14, 1991). Prepared by Wade Miller Associates.
USEPA 1994. Federal Actions to Address Environmental Justice in
Minority Populations and Low-Income Populations, 59 FR 7629,
February 16, 1994.
USEPA 1998a. ``A Fact Sheet on the Health Effects from Ionizing
Radiation.'' Prepared by the Office of Radiation & Indoor Air,
Radiation Protection Division. EPA 402-F-98-010. May 1998.
USEPA 1998b. Announcement of Small System Compliance Technology
Lists for Existing National Primary Drinking Water Regulations and
Findings Concerning Variance Technologies, 63 FR 42032, August 6, 1998.
USEPA 1998c. ``Ionizing Radiation Series No. 1.'' Prepared by the
Office of Radiation & Indoor Air, Radiation Protection Division. EPA
402-F-98-009. May 1998.
USEPA 1998d. National Primary Drinking Water Regulations: Consumer
Confidence; Proposed Rule 63 FR 7605, February 13, 1998.
USEPA 1998e. National Primary Drinking Water Regulation: Consumer
Confidence Reports; Final Rule, 63 FR 44511, August 19, 1998.
USEPA 1998f. ``Small System Compliance Technology List for the Non-
Microbial Contaminants Regulated Before 1996.'' EPA-815-R-98-002.
September 1998.
USEPA 1999a. ``Small Systems Compliance Technology List for the
Radionuclides Rule.'' Prepared by International Consultants, Inc.
Draft. April 1999.
USEPA 1999b. Cancer Risk Coefficients for Environmental Exposure to
Radionuclides, Federal Guidance Report No. 13. US Environmental
Protection Agency, Washington, DC, 1999.
USEPA 1999c. ``Inter Tribal Council of Arizona, Inc.: Ground Water
and Drinking Water Tribal Consultation Meeting.'' Executive Summary.
February 24-25, 1999.
USEPA 1999d. ``OGWDW Tribal Consultations: Workshops at the Annual
Conference of the National Tribal Environmental Council.'' May 18-
20, 1999.
USEPA 2000a. ``Comment/Response Document for the Radionuclides
Notice of Data Availability and 1991 Proposed Rule.'' Prepared by
Industrial Economics, Inc. for EPA. November 2000.
USEPA 2000b. ``Draft Toxicological Review of Uranium.'' Prepared by
the Office of Science and Technology. Draft. June 6, 2000.
USEPA 2000c. Government Dialogue on U.S. EPA's Upcoming Drinking
Water Regulations. Meeting Summary. May 30, 2000.
USEPA 2000d. ``Information Collection Request for National Primary
Drinking Water Regulations: Radionuclides''. Prepared by ISSI
Consulting Group, for EPA. September 22, 2000.
USEPA 2000e. National Primary Drinking Water Regulations;
Radionuclides; Notice of Data Availability; Proposed Rule. 65 FR
21577. April 21, 2000.
USEPA 2000f. ``Preliminary Health Risk Reduction and Cost Analysis:
Revised National Primary Drinking Water Standards for
Radionuclides.'' Prepared by Industrial Economics, Inc. for EPA.
Draft. January 2000.
USEPA 2000g. ``Economic Analysis of the Radionuclides National
Primary Drinking Water Regulations.'' Prepared by Industrial
Economics, Inc. for EPA. November 2000.
USEPA 2000h. ``Technical Support Document for the Radionuclides
Notice of Data Availability.'' Draft. March, 2000.
USEPA 2000i. ``Technologies and Costs for the Removal of
Radionuclides from Potable Water Supplies.'' Draft. Prepared by
Malcolm Pirnie, Inc. June, 2000.

List of Subjects

40 CFR Part 9

Reporting and recordkeeping requirements.

[[Page 76745]]

40 CFR Part 141

Environmental protection, Chemicals, Indians-lands, Incorporation
by reference, Intergovernmental relations, Radiation protection,
Reporting and recordkeeping requirements, Water supply.

40 CFR Part 142

Environmental protection, Administrative practice and procedure,
Chemicals, Indians-lands, Intergovernmental relations, Radiation
protection, Reporting and recordkeeping requirements, Water supply.

Dated: November 21, 2000.
Carol M. Browner,
Administrator.

For reasons set out in the preamble, 40 CFR parts 9, 141, and 142
are amended as follows:
1. The authority citation for part 9 continues to read as follows:

Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326-1330, 1324,
1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 1971-
1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-
1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3,
300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-
9657, 11023, 11048.

2. In Sec. 9.1 the table is amended by:
(a) Removing the entry for 141.25-141.30 and adding new entries for
141.25(a)-(e), 141.26 (a)-(b), and 141.27-141.30;
(b) Removing the entry for 142.14(a)-(d)(7) and adding new entries
for 142.14(a)-(d)(3), 142.14(d)(4)-(5), and 142.14(d)(6)-(7); and
(c) Removing the entry for 142.15(c)(5)-(d) and adding new entries
for 142.15(c)(5), 142.15(c)(6)-(7), and 142.15(d).
The additions read as follows:

Sec. 9.1 OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------
OMB control
40 CFR citation No.
------------------------------------------------------------------------

* * * * *
------------------------------------------------------------------------
National Primary Drinking Water Regulations
------------------------------------------------------------------------

* * * * *
141.25(a)-(e)............................................. 2040-0090
141.26(a)-(b)............................................. 2040-0228
141.27-141.30............................................. 2040-0090

* * * * *
------------------------------------------------------------------------
National Primary Drinking Water Regulations Implementation
------------------------------------------------------------------------

* * * *
142.14(a)-(d)(3).......................................... 2040-0090
142.14(d)(4)-(5).......................................... 2040-0228
142.14(d)(6)-(7).......................................... 2040-0090

* * * * *
142.15(c)(5).............................................. 2040-0090
142.15(c)(6)-(7).......................................... 2040-0228
142.15(d)................................................. 2040-0090
------------------------------------------------------------------------

* * * * *

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

1. The authority citation for part 141 continues to read as follows:

Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.

Subpart B--[Amended]

Secs. 141.15 and 141.16 [Removed]

2. Sections 141.15 and 141.16 are removed.

Subpart C--[Amended]

3. Section 141.25 is amended by:
a. Revising paragraph (a) introductory text (the table remains
unchanged),
b. Revising paragraph (c)(1),
c. Revising paragraph (c)(2) and redisgnating Table B in paragraph
(c)(2) as Table C and
d. Revising paragraph (d).
The revisions read as follows:

Sec. 141.25 Analytical methods for radioactivity.

(a) Analysis for the following contaminants shall be conducted to
determine compliance with Sec. 141.66 (radioactivity) in accordance
with the methods in the following table, or their equivalent determined
by EPA in accordance with Sec. 141.27.
* * * * *
(c) * * *
(1) To determine compliance with Sec. 141.66(b), (c), and (e) the
detection limit shall not exceed the concentrations in Table B to this
paragraph.

Table B.--Detection Limits for Gross Alpha Particle Activity, Radium
226, Radium 228, and Uranium
------------------------------------------------------------------------
Contaminant Detection limit
------------------------------------------------------------------------
Gross alpha particle activity.............. 3 pCi/L.
Radium 226................................. 1 pCi/L.
Radium 228................................. 1 pCi/L.
Uranium.................................... Reserve
------------------------------------------------------------------------

(2) To determine compliance with Sec. 141.66(d) the detection
limits shall not exceed the concentrations listed in Table C to this
paragraph.
* * * * *
(d) To judge compliance with the maximum contaminant levels listed
in Sec. 141.66, averages of data shall be used and shall be rounded to
the same number of significant figures as the maximum contaminant level
for the substance in question.
* * * * *

4. Section 141.26 is revised to read as follows:

Sec. 141.26 Monitoring frequency and compliance requirements for
radionuclides in community water systems

(a) Monitoring and compliance requirements for gross alpha particle
activity, radium-226, radium-228, and uranium.
(1) Community water systems (CWSs) must conduct initial monitoring
to determine compliance with Sec. 141.66(b), (c), and (e) by December
31, 2007. For the purposes of monitoring for gross alpha particle
activity, radium-226, radium-228, uranium, and beta particle and photon
radioactivity in drinking water, ``detection limit'' is defined as in
Sec. 141.25(c).
(i) Applicability and sampling location for existing community
water systems or sources. All existing CWSs using ground water, surface
water or systems using both ground and surface water (for the purpose
of this section hereafter referred to as systems) must sample at every
entry point to the distribution system that is representative of all
sources being used (hereafter called a sampling point) under normal
operating conditions. The system must take each sample at the same
sampling point unless conditions make another sampling point more
representative of each source or the State has designated a
distribution system location, in accordance with paragraph
(a)(2)(ii)(C) of this section.
(ii) Applicability and sampling location for new community water
systems or sources. All new CWSs or CWSs that use a new source of water

[[Page 76746]]

must begin to conduct initial monitoring for the new source within the
first quarter after initiating use of the source. CWSs must conduct
more frequent monitoring when ordered by the State in the event of
possible contamination or when changes in the distribution system or
treatment processes occur which may increase the concentration of
radioactivity in finished water.
(2) Initial monitoring: Systems must conduct initial monitoring for
gross alpha particle activity, radium-226, radium-228, and uranium as
follows:
(i) Systems without acceptable historical data, as defined below,
must collect four consecutive quarterly samples at all sampling points
before December 31, 2007.
(ii) Grandfathering of data: States may allow historical monitoring
data collected at a sampling point to satisfy the initial monitoring
requirements for that sampling point, for the following situations.
(A) To satisfy initial monitoring requirements, a community water
system having only one entry point to the distribution system may use
the monitoring data from the last compliance monitoring period that
began between June 2000 and December 8, 2003.
(B) To satisfy initial monitoring requirements, a community water
system with multiple entry points and having appropriate historical
monitoring data for each entry point to the distribution system may use
the monitoring data from the last compliance monitoring period that
began between June 2000 and December 8, 2003.
(C) To satisfy initial monitoring requirements, a community water
system with appropriate historical data for a representative point in
the distribution system may use the monitoring data from the last
compliance monitoring period that began between June 2000 and December
8, 2003, provided that the State finds that the historical data
satisfactorily demonstrate that each entry point to the distribution
system is expected to be in compliance based upon the historical data
and reasonable assumptions about the variability of contaminant levels
between entry points. The State must make a written finding indicating
how the data conforms to the these requirements.
(iii) For gross alpha particle activity, uranium, radium-226, and
radium-228 monitoring, the State may waive the final two quarters of
initial monitoring for a sampling point if the results of the samples
from the previous two quarters are below the detection limit.
(iv) If the average of the initial monitoring results for a
sampling point is above the MCL, the system must collect and analyze
quarterly samples at that sampling point until the system has results
from four consecutive quarters that are at or below the MCL, unless the
system enters into another schedule as part of a formal compliance
agreement with the State.
(3) Reduced monitoring: States may allow community water systems to
reduce the future frequency of monitoring from once every three years
to once every six or nine years at each sampling point, based on the
following criteria.
(i) If the average of the initial monitoring results for each
contaminant (i.e., gross alpha particle activity, uranium, radium-226,
or radium-228) is below the detection limit specified in Table B, in
Sec. 141.25(c)(1), the system must collect and analyze for that
contaminant using at least one sample at that sampling point every nine
years.
(ii) For gross alpha particle activity and uranium, if the average
of the initial monitoring results for each contaminant is at or above
the detection limit but at or below \1/2\ the MCL, the system must
collect and analyze for that contaminant using at least one sample at
that sampling point every six years. For combined radium-226 and
radium-228, the analytical results must be combined. If the average of
the combined initial monitoring results for radium-226 and radium-228
is at or above the detection limit but at or below \1/2\ the MCL, the
system must collect and analyze for that contaminant using at least one
sample at that sampling point every six years.
(iii) For gross alpha particle activity and uranium, if the average
of the initial monitoring results for each contaminant is above \1/2\
the MCL but at or below the MCL, the system must collect and analyze at
least one sample at that sampling point every three years. For combined
radium-226 and radium-228, the analytical results must be combined. If
the average of the combined initial monitoring results for radium-226
and radium-228 is above \1/2\ the MCL but at or below the MCL, the
system must collect and analyze at least one sample at that sampling
point every three years.
(iv) Systems must use the samples collected during the reduced
monitoring period to determine the monitoring frequency for subsequent
monitoring periods (e.g., if a system's sampling point is on a nine
year monitoring period, and the sample result is above \1/2\ MCL, then
the next monitoring period for that sampling point is three years).
(v) If a system has a monitoring result that exceeds the MCL while
on reduced monitoring, the system must collect and analyze quarterly
samples at that sampling point until the system has results from four
consecutive quarters that are below the MCL, unless the system enters
into another schedule as part of a formal compliance agreement with the
State.
(4) Compositing: To fulfill quarterly monitoring requirements for
gross alpha particle activity, radium-226, radium-228, or uranium, a
system may composite up to four consecutive quarterly samples from a
single entry point if analysis is done within a year of the first
sample. States will treat analytical results from the composited as the
average analytical result to determine compliance with the MCLs and the
future monitoring frequency. If the analytical result from the
composited sample is greater than \1/2\ MCL, the State may direct the
system to take additional quarterly samples before allowing the system
to sample under a reduced monitoring schedule.
(5) A gross alpha particle activity measurement may be substituted
for the required radium-226 measurement provided that the measured
gross alpha particle activity does not exceed 5 pCi/l. A gross alpha
particle activity measurement may be substituted for the required uranium
measurement provided that the measured gross alpha particle activity does
not exceed 15 pCi/l.
The gross alpha measurement shall have a confidence interval of 95%
(1.65, where is the standard deviation of the net
counting rate of the sample) for radium-226 and uranium. When a system
uses a gross alpha particle activity measurement in lieu of a radium-
226 and/or uranium measurement, the gross alpha particle activity
analytical result will be used to determine the future monitoring
frequency for radium-226 and/or uranium. If the gross alpha particle
activity result is less than detection, \1/2\ the detection limit will
be used to determine compliance and the future monitoring frequency.
(b) Monitoring and compliance requirements for beta particle and
photon radioactivity.
To determine compliance with the maximum contaminant levels in
Sec. 141.66(d) for beta particle and photon radioactivity, a system
must monitor at a frequency as follows:
(1) Community water systems (both surface and ground water)
designated by the State as vulnerable must sample for beta particle and
photon radioactivity. Systems must collect quarterly samples

[[Page 76747]]

for beta emitters and annual samples for tritium and strontium-90 at
each entry point to the distribution system (hereafter called a
sampling point), beginning within one quarter after being notified by
the State. Systems already designated by the State must continue to
sample until the State reviews and either reaffirms or removes the
designation.
(i) If the gross beta particle activity minus the naturally
occurring potassium-40 beta particle activity at a sampling point has a
running annual average (computed quarterly) less than or equal to 50
pCi/L (screening level), the State may reduce the frequency of
monitoring at that sampling point to once every 3 years. Systems must
collect all samples required in paragraph (b)(1) of this section during
the reduced monitoring period.
(ii) For systems in the vicinity of a nuclear facility, the State
may allow the CWS to utilize environmental surveillance data collected
by the nuclear facility in lieu of monitoring at the system's entry
point(s), where the State determines if such data is applicable to a
particular water system. In the event that there is a release from a
nuclear facility, systems which are using surveillance data must begin
monitoring at the community water system's entry point(s) in accordance
with paragraph (b)(1) of this section.
(2) Community water systems (both surface and ground water)
designated by the State as utilizing waters contaminated by effluents
from nuclear facilities must sample for beta particle and photon
radioactivity. Systems must collect quarterly samples for beta emitters
and iodine-131 and annual samples for tritium and strontium-90 at each
entry point to the distribution system (hereafter called a sampling
point), beginning within one quarter after being notified by the State.
Systems already designated by the State as systems using waters
contaminated by effluents from nuclear facilities must continue to
sample until the State reviews and either reaffirms or removes the
designation.
(i) Quarterly monitoring for gross beta particle activity shall be
based on the analysis of monthly samples or the analysis of a composite
of three monthly samples. The former is recommended.
(ii) For iodine-131, a composite of five consecutive daily samples
shall be analyzed once each quarter. As ordered by the State, more
frequent monitoring shall be conducted when iodine-131 is identified in
the finished water.
(iii) Annual monitoring for strontium-90 and tritium shall be
conducted by means of the analysis of a composite of four consecutive
quarterly samples or analysis of four quarterly samples. The latter
procedure is recommended.
(iv) If the gross beta particle activity beta minus the naturally
occurring potassium-40 beta particle activity at a sampling point has a
running annual average (computed quarterly) less than or equal to 15
pCi/L, the State may reduce the frequency of monitoring at that
sampling point to every 3 years. Systems must collect all samples
required in paragraph (b)(2) of this section during the reduced
monitoring period.
(v) For systems in the vicinity of a nuclear facility, the State
may allow the CWS to utilize environmental surveillance data collected
by the nuclear facility in lieu of monitoring at the system's entry
point(s), where the State determines if such data is applicable to a
particular water system. In the event that there is a release from a
nuclear facility, systems which are using surveillance data must begin
monitoring at the community water system's entry point(s) in accordance
with paragraph (b)(2) of this section.
(3) Community water systems designated by the State to monitor for
beta particle and photon radioactivity can not apply to the State for a
waiver from the monitoring frequencies specified in paragraph (b)(1) or
(b)(2) of this section.
(4) Community water systems may analyze for naturally occurring
potassium-40 beta particle activity from the same or equivalent sample
used for the gross beta particle activity analysis. Systems are allowed
to subtract the potassium-40 beta particle activity value from the
total gross beta particle activity value to determine if the screening
level is exceeded. The potassium-40 beta particle activity must be
calculated by multiplying elemental potassium concentrations (in mg/L)
by a factor of 0.82.
(5) If the gross beta particle activity minus the naturally
occurring potassium-40 beta particle activity exceeds the screening
level, an analysis of the sample must be performed to identify the
major radioactive constituents present in the sample and the
appropriate doses must be calculated and summed to determine compliance
with Sec. 141.66(d)(1), using the formula in Sec. 141.66(d)(2). Doses
must also be calculated and combined for measured levels of tritium and
strontium to determine compliance.
(6) Systems must monitor monthly at the sampling point(s) which
exceed the maximum contaminant level in Sec. 141.66(d) beginning the
month after the exceedance occurs. Systems must continue monthly
monitoring until the system has established, by a rolling average of 3
monthly samples, that the MCL is being met. Systems who establish that
the MCL is being met must return to quarterly monitoring until they
meet the requirements set forth in paragraph (b)(1)(ii) or (b)(2)(i) of
this section.
(c) General monitoring and compliance requirements for
radionuclides.
(1) The State may require more frequent monitoring than specified
in paragraphs (a) and (b) of this section, or may require confirmation
samples at its discretion. The results of the initial and confirmation
samples will be averaged for use in compliance determinations.
(2) Each public water systems shall monitor at the time designated
by the State during each compliance period.
(3) Compliance: Compliance with Sec. 141.66 (b) through (e) will be
determined based on the analytical result(s) obtained at each sampling
point. If one sampling point is in violation of an MCL, the system is
in violation of the MCL.
(i) For systems monitoring more than once per year, compliance with
the MCL is determined by a running annual average at each sampling
point. If the average of any sampling point is greater than the MCL,
then the system is out of compliance with the MCL.
(ii) For systems monitoring more than once per year, if any sample
result will cause the running average to exceed the MCL at any sample
point, the system is out of compliance with the MCL immediately.
(iii) Systems must include all samples taken and analyzed under the
provisions of this section in determining compliance, even if that
number is greater than the minimum required.
(iv) If a system does not collect all required samples when
compliance is based on a running annual average of quarterly samples,
compliance will be based on the running average of the samples collected.
(v) If a sample result is less than the detection limit, zero will
be used to calculate the annual average, unless a gross alpha particle
activity is being used in lieu of radium-226 and/or uranium. If the
gross alpha particle activity result is less than detection, \1/2\ the
detection limit will be used to calculate the annual average.
(4) States have the discretion to delete results of obvious
sampling or analytic errors.
(5) If the MCL for radioactivity set forth in Sec. 141.66 (b)
through (e) is exceeded, the operator of a community water system must
give notice to the

[[Page 76748]]

State pursuant to Sec. 141.31 and to the public as required by subpart
Q of this part.

Subpart F--[Amended]

5. A new Sec. 141.55 is added to subpart F to read as follows:

Sec. 141.55 Maximum contaminant level goals for radionuclides.

MCLGs for radionuclides are as indicated in the following table:

------------------------------------------------------------------------
Contaminant MCLG
------------------------------------------------------------------------
1. Combined radium-226 and radium-228........ Zero.
2. Gross alpha particle activity (excluding Zero.
radon and uranium).
3. Beta particle and photon radioactivity.... Zero.
4. Uranium................................... Zero.
------------------------------------------------------------------------

Subpart G--National Primary Drinking Water Regulations: Maximum
Contaminant Levels and Maximum Residual Disinfectant Levels

6. The heading of subpart G is revised as set out above.

7. A new Sec. 141.66 is added to subpart G to read as follows:

Sec. 141.66 Maximum contaminant levels for radionuclides.

(a) [Reserved]
(b) MCL for combined radium-226 and -228. The maximum contaminant
level for combined radium-226 and radium-228 is 5 pCi/L. The combined
radium-226 and radium-228 value is determined by the addition of the
results of the analysis for radium-226 and the analysis for radium-228.
(c) MCL for gross alpha particle activity (excluding radon and
uranium). The maximum contaminant level for gross alpha particle
activity (including radium-226 but excluding radon and uranium) is 15
pCi/L.
(d) MCL for beta particle and photon radioactivity. (1) The average
annual concentration of beta particle and photon radioactivity from
man-made radionuclides in drinking water must not produce an annual
dose equivalent to the total body or any internal organ greater than 4
millirem/year (mrem/year).
(2) Except for the radionuclides listed in table A, the
concentration of man-made radionuclides causing 4 mrem total body or
organ dose equivalents must be calculated on the basis of 2 liter per
day drinking water intake using the 168 hour data list in ``Maximum
Permissible Body Burdens and Maximum Permissible Concentrations of
Radionuclides in Air and in Water for Occupational Exposure,'' NBS
(National Bureau of Standards) Handbook 69 as amended August 1963, U.S.
Department of Commerce. This incorporation by reference was approved by
the Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. Copies of this document are available from the
National Technical Information Service, NTIS ADA 280 282, U.S.
Department of Commerce, 5285 Port Royal Road, Springfield, Virginia
22161. The toll-free number is 800-553-6847. Copies may be inspected at
EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460;
or at the Office of the Federal Register, 800 North Capitol Street,
NW., Suite 700, Washington, DC. If two or more radionuclides are
present, the sum of their annual dose equivalent to the total body or
to any organ shall not exceed 4 mrem/year.

Table A.--Average Annual Concentrations Assumed To Produce: a Total Body
or Organ Dose of 4 mrem/yr
------------------------------------------------------------------------

------------------------------------------------------------------------
1. Radionuclide............. Critical organ...... pCi per liter
2. Tritium.................. Total body.......... 20,000
3. Strontium-90............. Bone Marrow......... 8
------------------------------------------------------------------------

(e) MCL for uranium. The maximum contaminant level for uranium is
30 g/L.
(f) Compliance dates. (1) Compliance dates for combined radium-226
and -228, gross alpha particle activity, gross beta particle and photon
radioactivity, and uranium: Community water systems must comply with
the MCLs listed in paragraphs (b), (c), (d), and (e) of this section
beginning December 8, 2003 and compliance shall be determined in
accordance with the requirements of Secs. 141.25 and 141.26. Compliance
with reporting requirements for the radionuclides under appendix A to
subpart O and appendices A and B to subpart Q is required on December
8, 2003.
(g) Best available technologies (BATs) for radionuclides. The
Administrator, pursuant to section 1412 of the Act, hereby identifies
as indicated in the following table the best technology available for
achieving compliance with the maximum contaminant levels for combined
radium-226 and -228, uranium, gross alpha particle activity, and beta
particle and photon radioactivity.

Table B.--BAT for Combined Radium-226 and Radium-228, Uranium, Gross
Alpha Particle Activity, and Beta Particle and Photon Radioactivity
------------------------------------------------------------------------
Contaminant BAT
------------------------------------------------------------------------
1. Combined radium-226 and radium-228.. Ion exchange, reverse osmosis,
lime softening.
2. Uranium............................. Ion exchange, reverse osmosis,
lime softening, coagulation/
filtration.
3. Gross alpha particle activity Reverse osmosis.
(excluding Radon and Uranium).
4. Beta particle and photon Ion exchange, reverse osmosis.
radioactivity.
------------------------------------------------------------------------

(h) Small systems compliance technologies list for radionuclides.

[[Page 76749]]

Table C.--List of Small Systems Compliance Technologies for Radionuclides and Limitations to Use
----------------------------------------------------------------------------------------------------------------
Limitations
Unit technologies (see Operator skill level Raw water quality range and
footnotes) required \1\ considerations.\1\
----------------------------------------------------------------------------------------------------------------
1. Ion exchange (IE)................... (a) Intermediate.............. All ground waters.
2. Point of use (POU \2\) IE........... (b) Basic..................... All ground waters.
3. Reverse osmosis (RO)................ (c) Advanced.................. Surface waters usually
require pre-filtration.
4. POU\2\ RO........................... (b) Basic..................... Surface waters usually
require pre-filtration.
5. Lime softening...................... (d) Advanced.................. All waters.
6. Green sand filtration............... (e) Basic. .............................
7. Co-precipitation with Barium sulfate (f) Intermediate to Advanced.. Ground waters with suitable
water quality.
8. Electrodialysis/electrodialysis ............ Basic to Intermediate..... All ground waters.
reversal.
9. Pre-formed hydrous Manganese oxide (g) Intermediate.............. All ground waters.
filtration.
10. Activated alumina.................. (a), (h) Advanced.................. All ground waters; competing
anion concentrations may
affect regeneration
frequency.
11. Enhanced coagulation/filtration.... (i) Advanced.................. Can treat a wide range of
water qualities.
----------------------------------------------------------------------------------------------------------------
\1\ National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities.
National Academy Press. Washington, D.C. 1997.
\2\ A POU, or ``point-of-use'' technology is a treatment device installed at a single tap used for the purpose
of reducing contaminants in drinking water at that one tap. POU devices are typically installed at the kitchen
tap. See the April 21, 2000 NODA for more details.

Limitations Footnotes: Technologies for Radionuclides:
a The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be
carefully considered before choosing this technology.
b When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring must
be provided by water utility to ensure proper performance.
c Reject water disposal options should be carefully considered before choosing this technology. See other RO
limitations described in the SWTR Compliance Technologies Table.
d The combination of variable source water quality and the complexity of the water chemistry involved may make
this technology too complex for small surface water systems.
e Removal efficiencies can vary depending on water quality.
f This technology may be very limited in application to small systems. Since the process requires static mixing,
detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate levels that
already have a suitable filtration treatment train in place.
g This technology is most applicable to small systems that already have filtration in place.
h Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems
without an adequately trained operator.
i Assumes modification to a coagulation/filtration process already in place.

Table D.--Compliance Technologies by System Size Category for Radionuclide NPDWR's
----------------------------------------------------------------------------------------------------------------
Compliance technologies \1\ for system size
categories (population served)
Contaminant -------------------------------------------------- 3,300-10,000
25-500 501-3,300
----------------------------------------------------------------------------------------------------------------
1. Combined radium-226 and radium-228 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7. 8,
9. 9. 9.
2. Gross alpha particle activity..... 3, 4................... 3, 4................... 3, 4.
3. Beta particle activity and photon 1, 2, 3, 4............. 1, 2, 3, 4............. 1, 2, 3, 4.
activity.
4. Uranium........................... 1, 2, 4, 10, 11........ 1, 2, 3, 4, 5, 10, 11.. 1, 2, 3, 4, 5, 10, 11.
----------------------------------------------------------------------------------------------------------------
Note: 1 Numbers correspond to those technologies found listed in the table C of 141.66(h).

Subpart O--[Amended]

8. The table in appendix A to subpart O is amended under the
heading ``Radioactive contaminants'' by revising the entries for
``Beta/photon emitters (mrem/yr)'', ``Alpha emitters
(pCi/l)'', and ``Combined radium (pCi/l)'' and adding a new entry for
``Uranium (pCi/L)'' to read as follows:

[[Page 76750]]

Appendix A to Subpart O--Regulated Contaminants

--------------------------------------------------------------------------------------------------------------------------------------------------------
To
convert
Contaminant units Traditional MCL in mg/L for CCR, MCL in MCLG Major sources in Health effects language
multiply CCR units drinking water
by
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *
Radioactive contaminants:
Beta/photon emitters (mrem/yr).. 4 mrem/yr................... - 4 0 Decay of natural and Certain minerals are
man-made deposits. radioactive and may emit
forms of radiation known
as photons and beta
radiation. Some people who
drink water containing
beta particle and photon
radioactivity in excess of
the MCL over many years
may have an increased risk
of getting cancer.
Alpha emitters (pCi/L).......... 15 pCi/L.................... - 15 0 Erosion of natural Certain minerals are
deposits. radioactive and may emit a
form of radiation known as
alpha radiation. Some
people who drink water
containing alpha emitters
in excess of the MCL over
many years may have an
increased risk of getting
cancer.
Combined radium (pCi/L)......... 5 pCi/L..................... - 5 0 Erosion of natural Some people who drink water
deposits. containing radium-226 or -
228 in excess of the MCL
over many years may have
an increased risk of
getting cancer.
Uranium (pCi/L)................. 30 g/L............. - 30 0 Erosion of natural Some people who drink water
deposits. containing uranium in
excess of the MCL over
many years may have an
increased risk of getting
cancer and kidney
toxicity.

* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

Subpart Q--[Amended]

9. Appendix A to subpart Q under I.F. ``Radioactive contaminants''
is amended by:
a. Revising entries 1, 2, and 3;
b. Adding entry 4;
c. Redesignating endnotes 9 through 17 as endnotes 11 through 19;
and
d. Adding new endnotes 9 and 10.

Appendix A to Subpart Q--NPDWR Violations and Other Situations
Requiring Public Notice \1\

----------------------------------------------------------------------------------------------------------------
MCL/MRDL/TT Violations Monitoring and testing
\2\ procedure violations
---------------------------------------------------
Contaminant Tier of Tier of
public public
notice Citation notice Citation
required required
----------------------------------------------------------------------------------------------------------------

I. Violations of National Primary Drinking Water Regulations (NPDWR) \3\

* * * * * *
*
F. Radioactive contaminants

1. Beta/photon emitters..................................... 2 141.66(d) 3 141.25(a)
141.26(b)
2. Alpha emitters........................................... 2 141.66(c) 3 141.25(a)
141.26(a)
3. Combined radium (226 and 228)............................ 2 141.66(b) 3 141.25(a)
141.26(a)
4. Uranium.................................................. \9\ 2 141.66(e) \10\ 3 141.25(a)
141.26(a)

* * * * * *
*
----------------------------------------------------------------------------------------------------------------

Appendix A--Endnotes

* * * * *
1. Violations and other situations not listed in this table
(e.g., reporting violations and failure to prepare Consumer
Confidence Reports), do not require notice, unless otherwise
determined by the primary agency. Primacy agencies may, at their
option, also

[[Page 76751]]

require a more stringent public notice tier (e.g., Tier 1 instead of
Tier 2 or Tier 2 instead of Tier 3) for specific violations and
situations listed in this Appendix, as authorized under Sec.
141.202(a) and Sec. 141.203(a).
2. MCL--Maximum contaminant level, MRDL--Maximum residual
disinfectant level, TT--Treatment technique.
3. The term Violations of National Primary Drinking Water
Regulations (NPDWR) is used here to include violations of MCL, MRDL,
treatment technique, monitoring, and testing procedure requirements.
* * * * *
9. The uranium MCL Tier 2 violation citations are effective
December 8, 2003 for all community water systems.
10. The uranium Tier 3 violation citations are effective
December 8, 2000 for all community water systems.
* * * * *
10. Appendix B to Subpart Q is amended by:
a. Redesignating entries 79 through 84 and 86 through 88 as 80
through 85 and 87 through 89, respectively, and entries 85a and 85b
as 86a and 86b, respectively;
b. Adding a new entry 79 for uranium under ``G. Radioactive
contaminants'';
c. Redesignating endnote entries 16 through 21 as 17 through 22;
and
d. adding a new endnote 16.

Appendix B to Subpart Q--Standard Health Effects Language for
Public Notification

----------------------------------------------------------------------------------------------------------------
Standard health effects
Contaminant MCLG\1\ mg/L MCL\2\ mg/L language for public
notification
----------------------------------------------------------------------------------------------------------------
National Primary Drinking Water Regulations
(NPDWR)

* * * * * *
*
G. Radioactive contaminants

* * * * * *
*
79. Uranium\16\............................. Zero................ 30 g/L.... Some people who drink
water containing
uranium in excess of
the MCL over many
years may have an
increased risk of
getting cancer and
kidney toxicity.

* * * * * *
*
----------------------------------------------------------------------------------------------------------------

Appendix B--Endnotes

1. MCLG--Maximum contaminant level goal
2. MCL--Maximum contaminant level
* * * * *
16. The uranium MCL is effective December 8, 2003 for all
community water systems.
* * * * *

PART 142--NATIONAL PRIMARY DRINKING WATER REGULATIONS
IMPLEMENTATION

1. The authority citation for part 142 continues to read as
follows:

Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.

Subpart B--Primary Enforcement Responsibility

2. Section 142.16 is amended by adding and reserving paragraphs
(i), (j), and (k) and adding a new paragraph (l) to read as follows:

Sec. 142.16 Special primacy requirements.

* * * * *
(i)-(k) [Reserved]
(l) An application for approval of a State program revision for
radionuclides which adopts the requirements specified in
Sec. 141.26(a)(2)(ii)(C) of this chapter must contain the following (in
addition to the general primacy requirements enumerated in this part,
including that State regulations be at least as stringent as the
Federal requirements):
(1) If a State chooses to use grandfathered data in the manner
described in Sec. 141.26(a)(2)(ii)(C) of this chapter, then the State
must describe the procedures and criteria which it will use to make
these determinations (whether distribution system or entry point
sampling points are used).
(i) The decision criteria that the State will use to determine that
data collected in the distribution system are representative of the
drinking water supplied from each entry point to the distribution
system. These determinations must consider:
(A) All previous monitoring data.
(B) The variation in reported activity levels.
(C) Other factors affecting the representativeness of the data
(e.g. geology).
(ii) [Reserved]
(2) A monitoring plan by which the State will assure all systems
complete the required monitoring within the regulatory deadlines.
States may update their existing monitoring plan or use the same
monitoring plan submitted for the requirements in Sec. 142.16(e)(5)
under the national primary drinking water regulations for the inorganic
and organic contaminants (i.e. the phase II/V rules). States may note
in their application any revision to an existing monitoring plan or
note that the same monitoring plan will be used. The State must
demonstrate that the monitoring plan is enforceable under State law.

Subpart G--[Amended]

3. Section 142.65 is added to read as follows.

Sec. 142.65 Variances and exemptions from the maximum contaminant
levels for radionuclides.

(a)(1) Variances and exemptions from the maximum contaminant levels
for combined radium-226 and radium-228, uranium, gross alpha particle
activity (excluding Radon and Uranium), and beta particle and photon
radioactivity. (i) The Administrator, pursuant to section 1415(a)(1)(A)
of the Act, hereby identifies the following as the best available
technology, treatment techniques, or other means available for
achieving compliance with the maximum contaminant levels for the
radionuclides listed in Sec. 141.66(b), (c), (d), and (e) of this
chapter, for the purposes of issuing variances and exemptions, as shown
in Table A to this paragraph.

[[Page 76752]]

Table A.--BAT for Radionuclides Listed in Sec. 141.66
------------------------------------------------------------------------
Contaminant BAT
------------------------------------------------------------------------
Combined radium-226 and radium-228..... Ion exchange, reverse osmosis,
lime softening.
Uranium................................ Ion exchange, reverse osmosis,
lime softening, coagulation/
filtration.
Gross alpha particle activity Reverse osmosis.
(excluding radon and uranium).
Beta particle and photon radioactivity. Ion exchange, reverse osmosis.
------------------------------------------------------------------------

(ii) In addition, the Administrator hereby identifies the following
as the best available technology, treatment techniques, or other means
available for achieving compliance with the maximum contaminant levels
for the radionuclides listed in Sec. 141.66(b), (c), (d), and (e) of
this chapter, for the purposes of issuing variances and exemptions to
small drinking water systems, defined here as those serving 10,000
persons or fewer, as shown in Table C to this paragraph.

Table B.--List of Small Systems Compliance Technologies for Radionuclides and Limitations to Use
----------------------------------------------------------------------------------------------------------------
Limitations
Unit technologies (see Operator skill level required Raw water quality range &
footnotes) \1\ considerations \1\
----------------------------------------------------------------------------------------------------------------
1. Ion exchange (IE)................. (\a\) Intermediate................. All ground waters.
2. Point of use (POU \2\ ) IE........ (\b\) Basic........................ All ground waters.
3. Reverse osmosis (RO).............. (\c\) Advanced..................... Surface waters usually
require pre-filtration.
4. POU \2\ RO........................ (\b\) Basic........................ Surface waters usually
require pre-filtration.
5. Lime softening.................... (\d\) Advanced..................... All waters.
6. Green sand filtration............. (\e\) Basic.
7. Co-precipitation with barium (\f\) Intermediate to Advanced..... Ground waters with suitable
sulfate. water quality.
8. Electrodialysis/electrodialysis Basic to Intermediate........ All ground waters.
reversal.
9. Pre-formed hydrous manganese oxide (\g\) Intermediate................. All ground waters.
filtration.
10. Activated alumina................ (\a\), (\h\) Advanced..................... All ground waters; competing
anion concentrations may
affect regeneration
frequency.
11. Enhanced coagulation/filtration.. (\i\) Advanced..................... Can treat a wide range of
water qualities.
----------------------------------------------------------------------------------------------------------------
\1\ National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities.
National Academy Press. Washington, D.C. 1997.
\2\ A POU, or ``point-of-use'' technology is a treatment device installed at a single tap used for the purpose
of reducing contaminants in drinking water at that one tap. POU devices are typically installed at the kitchen
tap. See the April 21, 2000 NODA for more details.

Limitations Footnotes: Technologies for Radionuclides:
\a\ The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be
carefully considered before choosing this technology.
\b\ When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring must
be provided by water utility to ensure proper performance.
\c\ Reject water disposal options should be carefully considered before choosing this technology. See other RO
limitations described in the SWTR compliance technologies table.
\d\ The combination of variable source water quality and the complexity of the water chemistry involved may make
this technology too complex for small surface water systems.
\e\ Removal efficiencies can vary depending on water quality.
\f\ This technology may be very limited in application to small systems. Since the process requires static
mixing, detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate
levels that already have a suitable filtration treatment train in place.
\g\ This technology is most applicable to small systems that already have filtration in place.
\h\ Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems
without an adequately trained operator.
\i\ Assumes modification to a coagulation/filtration process already in place.

Table C.--BAT for Small Community Water Systems for the Radionuclides Listed in Sec. 141.66
----------------------------------------------------------------------------------------------------------------
Compliance technologies \1\ for system size categories (population
Contaminant ----------------------------------served)---------------------------------
25-500 501-3,300 3,300-10,000
----------------------------------------------------------------------------------------------------------------
Combined radium-226 and radium-228... 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8,
9. 9. 9.
Gross alpha particle activity........ 3, 4................... 3, 4................... 3, 4.
Beta particle activity and photon 1, 2, 3, 4............. 1, 2, 3, 4............. 1, 2, 3, 4.
activity.
Uranium.............................. 1, 2, 4, 10, 11........ 1, 2, 3, 4, 5, 10, 11.. 1, 2, 3, 4, 5, 10, 11.
----------------------------------------------------------------------------------------------------------------
\1\ Note: Numbers correspond to those technologies found listed in the table B to this paragraph.

(2) A State shall require community water systems to install and/or
use any treatment technology identified in Table A to this section, or
in the case of small water systems (those serving 10,000 persons or
fewer), Table B and Table C

[[Page 76753]]

of this section, as a condition for granting a variance except as
provided in paragraph (a)(3) of this section. If, after the system's
installation of the treatment technology, the system cannot meet the
MCL, that system shall be eligible for a variance under the provisions
of section 1415(a)(1)(A) of the Act.
(3) If a community water system can demonstrate through
comprehensive engineering assessments, which may include pilot plant
studies, that the treatment technologies identified in this section
would only achieve a de minimus reduction in the contaminant level, the
State may issue a schedule of compliance that requires the system being
granted the variance to examine other treatment technologies as a
condition of obtaining the variance.
(4) If the State determines that a treatment technology identified
under paragraph (a)(3) of this section is technically feasible, the
Administrator or primacy State may require the system to install and/or
use that treatment technology in connection with a compliance schedule
issued under the provisions of section 1415(a)(1)(A) of the Act. The
State's determination shall be based upon studies by the system and
other relevant information.
(5) The State may require a community water system to use bottled
water, point-of-use devices, point-of-entry devices or other means as a
condition of granting a variance or an exemption from the requirements
of Sec. 141.66 of this chapter, to avoid an unreasonable risk to health.
(6) Community water systems that use bottled water as a condition
for receiving a variance or an exemption from the requirements of
Sec. 141.66 of this chapter must meet the requirements specified in
either Sec. 142.62(g)(1) or Sec. 142.62(g)(2) and (g)(3).
(7) Community water systems that use point-of-use or point-of-entry
devices as a condition for obtaining a variance or an exemption from
the radionuclides NPDWRs must meet the conditions in Sec. 142.62(h)(1)
through (h)(6).

[FR Doc. 00-30421 Filed 12-6-00; 8:45 am]
BILLING CODE 6560-50-U

Notices For
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National Primary Drinking Water Regulations; Radionuclides; Final Rule

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