[Federal Register Volume 65, Number 236 (Thursday, December 7, 2000)]
[Rules and Regulations]
[Pages 76708-76753]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-30421]



[[Page 76707]]

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Part II





Environmental Protection Agency





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40 CFR Parts 9, 141, and 142



National Primary Drinking Water Regulations; Radionuclides; Final Rule

  Federal Register / Vol. 65 , No. 236 / Thursday, December 7, 2000 / 
Rules and Regulations  

[[Page 76708]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9, 141, and 142

[FRL-6909-3]
RIN 2040-AC98


National Primary Drinking Water Regulations; Radionuclides; Final 
Rule

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
g/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).
---------------------------------------------------------------------------

    \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
----------------------------------------------------------------------------------------------------------------
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